Final Report Summary - OPTIMORE (Optimised Modular Range Extender for every day customer usage)
Executive Summary:
Worldwide, there is a strong trend towards highly efficient, low (preferably zero) emission vehicles, i.e. electrical vehicles. Electric Vehicles are able to cover almost 80% of average travel needs. However, many vehicle users require occasional longer distance travel capabilities of their vehicle. To relief this so-called “range anxiety”, there is a need for advanced plug-in hybrids and electrical vehicles with range extenders for regular customer duty. For this purpose, highly efficient, compact, clean and low cost engines are developed in this project OptiMoRE. Three different RE concepts of OPTIMORE will be developed and demonstrated to serve the niches from city vehicles over medium sized passenger cars up to light commercial vehicles.
The CONCEPT of OptiMoRE is based upon the following major elements:
1. Definition of real world driving conditions (driving cycles and comfort requirements) as a baseline for further optimisation and EV assessment
2. Optimisation of components and the whole RE system regarding emission, fuel consumption, cost, weight and exhaust gas after-treatment
3. Modular setup of an EV concept to fulfil a wide range of customer expectations
4. Advanced control strategies as a key for cost reduction and system optimisation
5. Functional and Electrical safety analysis and concept development to define measures necessary according to the ISO 26262 standard
6. Build-up and optimisation of three technology demonstrator vehicles covering EV aspects for delivery trucks, all-purpose vehicles and city cars.
The main results achieved can be described as follows:
A Commercial Vehicle moving to efficiency in real driving cycles and approaching industrial sustainability is developed, build up and demonstrated and an overall weight reduction of the RE unit is 126 kg (approx. 50% reduction) compared to FUEREX is achieved. Further, the vehicle defined three main working points for the Range Extender: 20, 15 and 10 kW of electrical power at battery terminals.
The second demonstrator is achieved: the Modular Electric Range Extender vehicle. The Volvo passenger car modular approach contains three different drivetrains which can be integrated into one electrified powertrain platform. It contains of a tunnel battery and an optional rear drivetrain providing different attributes and resulting cost. The concept itself fulfills the requirements for Euro 6 emission levels. Within the RE development also the Human Machine Interface (HMI) is closely examined to find a non distrurbing ECO-Coach function started with case study what problems which occur related to limited electric range. The new HMI concept is implemented in a demonstrator vehicle.
The City Electric Range Extender Vehicle was optimised in the system layout, improved in the hardware and the software was industrialised. This all with the aim to reduce the cost and to optimise the whole system based on the detailed development. The final result was a demonstrator vehicle fully functional and operational.
Next to the three demonstrator vehicles, a functional safety development took place and resulted in the generic functional safety concept and is developed based on the methodical and structural principles described in the ISO 26262. According to the definition the following set was created: Generic Item Definition for RE-EVs, Generic Hazard and Risk Analysis for RE-EVs, Generic powertrain system FMEA for RE-EVs and Generic Functional Safety Concept for RE-EVs.
The final achievement was the development of an Optimization routine for Range Extenders, battery sizes and controls for different vehicle niches. The theoretical study was assessed and evaluated based on real drive cycles and drive missions, collected in a database in Sweden. The definition of real world driving conditions (driving cycles and comfort requirements) was achieved as a baseline for further optimization and EV assessment. This is based on Real world conditions for specific vehicle niche markets set the baseline for defining drive cycles, driving/usage profiles and customer demands. Also, environmental circumstances which influence emissions, heating, ventilation, air-conditioning and cooling (HVAC) are taken into account, as these aspects have a significant influence on the optimum REX design.
Project Context and Objectives:
2.1 Project Context
Worldwide, there is a strong trend towards highly efficient, low (preferably zero) emission vehicles, e.g. electrical vehicles. Factors that contribute to this trend are widespread concerns on: global warming and climate change (as effect of rising atmospheric CO2 concentrations), air quality (especially in urban areas: adverse health effect) and decreasing availability and dependency of fossil fuels.
Electric vehicles are able to cover almost 80% of average travel needs. However, many vehicle users require occasional longer distance travel capabilities of their vehicle. To relief this so-called “range anxiety”, there is a need for advanced plug-in hybrids and electric vehicles with range extenders for regular customer duty. For this purpose, highly efficient, compact, clean and low cost engines are required. Such systems are developed to provide battery charging over longer trips and/or in areas where electric recharge infrastructure is not (yet) available. For many application cases the target is to develop an electric vehicle for city driving with the ability to cover longer driving distances without any limitations compared to today’s vehicle comfort.
Most of the proposers of OPTIMORE are participating in the on-going FP7 project FUEREX . The main objective of the FUEREX project is to define and prove the best technology for range extenders from sub-compact passenger cars to light duty trucks in order to allow large market penetration of electric vehicles. Three types of spark ignition engines are being developed, capable of using renewable bio fuels as well as regular fossil fuels. This technology will enable a large reduction of CO2 emissions from passenger cars and light duty vehicles, since the market share of electric vehicles equipped with range extenders is expected to be much higher than for pure battery electric vehicles, due to both lower cost and higher driving range. Each of the developed range extenders are integrated and tested in a vehicle.
The major results of the FUEREX project are:
• Three range extenders demonstrating state of the art performance and integration
• Bench test demonstrating emissions, efficiency and performance for total RE
• Vehicle test demonstrating integration/NVH and vehicle performance.
OPTIMORE focuses on solving and overcoming well known shortcomings of BEVs and further develops and optimizes the range extender concepts from FUEREX results and experiences, simultaneously creating an important path towards customer acceptance of electrified vehicles and increasing the market penetration.
2.2 Concept and objectives
2.2.1 Concept of the OPTIMORE project
The OPTIMORE project takes on the challenge to develop and optimize the concept of the fully-integrated, range-extended, electrified light duty vehicle. Three different RE concepts will be developed and demonstrated to serve the niches from city vehicles, medium sized passenger cars up to light commercial vehicles.
The CONCEPT of OPTIMORE is based upon the following major elements.
The elements, their features and the major innovations are:
1. Definition of real world driving conditions (driving cycles and comfort requirements) as a baseline for further optimization and EV assessment
a. Real world conditions for specific vehicle niche markets set the baseline for defining drive cycles, driving/usage profiles and customer demands. Also, environmental circumstances which influence emissions, heating, ventilation, air-conditioning and cooling (HVAC) are taken into account, as these aspects have a significant influence on the optimum REX design.
2. Optimization of components and the whole RE system regarding emission, fuel consumption, cost, weight and exhaust gas after-treatment
a. Partly based on the results and the hardware of the FUEREX project the following further development will be performed: Optimization of REX for optimal battery capacity, REX power, emissions costs and control strategy cannot be divided into separate optimizations where the objectives are optimized one by one, as the different objectives are closely interconnected and partly in conflict with each other. A method is used that allows simultaneous optimization of the whole concept. What makes it even more challenging is that the optimization will be made not just for one typical driving cycle, but for a large set of driving cycles representing different types of users and different traffic environments.
3. Modular setup of an EV concept to fulfil a wide range of customer expectations
a. The experience with EVs up to now shows that this technology is too expensive. A modular setup / approach allows the same vehicle to be equipped with different drivelines based on customer demand. This enables OEMs to offer the optimum efficiency, functionality and cost for different customers. The same base vehicle, Volvo C30 electric will be analysed in three different versions: Pure electric drive only for short driving cycles, series range extender for city oriented use and parallel range extender for more highway use.
4. Advanced control strategies as a key for cost reduction and system optimization
a. Actual driving environment information like temperatures, speed, exterior and interior NVH levels;
b. Predictive driving and routing information, either taken from GPS based navigation type systems or from learned driving patterns.
c. This enables amongst others storage of energy in advance, providing backup for the REX in extreme situations and utilising REX for heating and cooling of the vehicle. But also, to enable fully electric driving where it is highly desirable (or even mandatory) such as in the centres of a growing number of cities.
d. Such control strategies have great potential for optimizing the performance over the trip in terms of comfort, fuel efficiency, emission as well as for achieving low overall system cost.
5. Functional and Electrical safety analysis and concept development to define necessary measures to fulfil and implement the ISO 26262 standard
a. The electrical system on board the EV-RE complies with the ISO 26262 functional safety standard for road vehicles. This primarily concerns the high voltage (HV) components on board and the precautions/measures to be taken in this respect.
6. Build-up and optimization of three technology demonstrator vehicles covering EV aspects for delivery trucks, all-purpose vehicles and city cars.
a. The build-up of demo vehicles is very expensive and time consuming. Within OPTIMORE it is only possible due to the fact that the consortium has already acquired knowledge and built-up first prototypes in FUEREX which will be utilized in OPTIMORE. This helps not only to keep the OPTIMORE budget, but it is an ideal situation to improve the technology in a very target oriented way. Three Fully Electric Vehicles (FEV) equipped with range extenders will demonstrate the largest potential to meet the customer demands in terms of efficiency, NVH, fuel type, exhaust emissions, dimensions, weight and costs. The three concepts are:
b. City compact electric vehicle, equipped with an innovative rotary engine for medium term (2020+);
c. A family (medium passenger) of new electric vehicles either as FEV or EV-RE equipped with a 3 cylinder piston engine (VCC/AVL-Schrick) used in a modular way, based on customer demands and their needs on the short term (2020+);
d. Light commercial electric vehicle, equipped with a 2 cylinder piston engine (CRF) optimized for weight and costs with an application on light commercial vehicles on the short term (2015+).
OPTIMORE takes on the challenge of simultaneously meeting the tough efficiency, emission, noise vibration and harshness (NVH), integration and cost requirements for a range extender. Each of the requirements can be met separately, but the main challenge lies in meeting them all and optimizing them at the same time - and - at a low enough cost to represent a competitive solution for the customer demands.
OPTIMORE targets for finding solutions – for both short and medium term – have large impact in terms of volume (market segments and number of vehicles) and ecological footprint (reduced (CO2) emissions, well to wheel efficiency, optimized weight and costs, etc.). The developed range extender concepts are expected to be very competitive, in comparison with battery electric vehicles but also in comparison with plug-in hybrid vehicles with a more traditional ICE power train, and therefore have the potential to be the main solution for passenger cars in the medium term perspective.
2.3 Objectives – Commercial Vehicle moving to efficiency in real driving cycles and approaching industrial sustainability
To approach industrial sustainability, RE components will be improved and optimized to reduce costs, weight and volume and to improve efficiency
To increase system overall efficiency during vehicle lifetime also an optimized hybrid capability will be implemented in an optimized range extender control SW.
1. Cost, weight and volume optimization of REX unit in light commercial Vehicle. Target weight reduction for REX is 20% together with a reduction of Range Extender length by 25%respect to FUEREX configuration.
2. RE fuel consumption and emission optimization acting both on ICE and electric machine efficiency and RE utilization strategies. Emission target is to match half of EuroVI standard with a correspondent best BSFC of 230gr/kWh.
3. Standardisation and modularization
Main results:
- Reduced Range Extender costs, weight and volume
- Improved Range Extender efficiency and emissions
- Improved control SW capability, including hybrid mode
2.4 Objectives – Modular Electric Range Extender vehicle
A modular approach towards an electric vehicle, which can be equipped with either an extra battery, a Range Extender for extra urban use or an ICE turbo charged with gearbox Range Extender for longer trips. With the help of this approach the electric vehicle can satisfy the needs of many potential customers.
Main results:
- An optimized parallel / serial Electric demonstrator Vehicle (Volvo C30/Volvo V60) in a modular way.
- Human Machine Interface for driver/user.
- Establish the correct controls for optimal use of the power sources in the vehicle (ICE, E-motor, E-motor/generator)
2.5 Objectives – Electric Vehicle – City car
Here, the approach is to develop an electric city vehicle equipped with a Rotary engine range extender. The operating system for the electric city vehicle will be adapted to real world operating conditions with special attention to user comfort needs and emission requirements. Reliability, performance and cost of needed hardware will be optimized and identified to reflect production intent material, cost and safety level.
Main results:
- Optimized hardware and advanced operating strategy for real world driving conditions
- Verification of ISO 26262 compliance for operating system.
- Identification of cost reduction potentials for volume production.
2.6 Objectives – Functional Safety Development
A functional safety concept will be worked out to assure safety in electric and hybrid vehicles containing a high voltage battery. Herein potential hazards due to torque handling of the appropriate control units as well as the high voltage contact safety will be considered. Potential risks will be minimized by both hardware and software measures.
Main results:
- HV contact safety
- HV battery technology safety (in terms of overloading, overheating, etc.)
- Control algorithm monitoring features
2.7 Objectives – Optimization of range extender, battery size and control for different vehicle niches
The optimization method and the analysis of optimal sizing for different vehicles are aimed to support the commercialization of the REX technologies, rather than to optimize the demonstrator vehicles within OPTIMORE. The demonstrator vehicle will show that the technologies meet the expectations, while the ability to define attractive and cost effective REX systems for a wide set of vehicles will be demonstrated through a theoretical simulation study.
Main results:
- Defined driving cycles to be used for the optimization of the range extender sizes, describing typical use for the investigated vehicle types, the variations between different type of drivers and environments needed to create robust range extender concepts.
- Knowhow and computer algorithms to optimize the size of the range extender and the battery size as well as the control strategy using the driving cycles developed. Especially this includes algorithms to optimally decide the sizing of a number of vehicles for a vehicle market represented by the drive cycles of the drivers. This gives the optimal division of the set of drivers into subsets, distinct vehicle niches, and the sizing of each niche.
- Knowhow of the relationship between driving cycles and REX performance in order to design optimal REX solutions for defined niches.
2.8 Objectives – Dissemination and exploitation
Main objective of this work package is to establish an appropriate and effective communication of the project results towards relevant stakeholders and the automotive community in general.
Main results:
- Dissemination plan
- Project website for dissemination to the broad public
- Workshop for relevant stakeholders
Project Results:
This chapter describes the main achievements of the project per main objective.
3.1 Commercial Vehicle moving to efficiency in real driving cycles and approaching industrial sustainability (Fuel consumption, efficiency and emission optimization)
Main results for the Optimore Electric Daily Range Extender version come from the experience of the Iveco Daily Electric major customers: according to the data of the usage of their vehicle, in general, Electric LCV daily mission for urban delivery is around 80 km per day. Sometime having suburban operation as well increased mileage can be necessary and for this reason a hypothetic daily cycle was identified:
52 Km for SUBURBAN CYCLE (≈60%)
33 Km for URBAN /DOOR TO DOOR CYCLE (≈40%)
Respectively divided in:
14 km at the average speed of 11Km/h - (URBAN)
18 Km at the average speed of 6,7Km/h - (DOOR TO DOOR)
52 Km at the average speed of 50 Km/h - (SUBURBAN)
With an average speed of 14km/h.
Have been considered 230 working days and a consequential mileage around 20.000 km/year; with this kind of cycle the possible situation that occurs each time SOC decreases below 40% and the range anxiety rises for the driver has been covered.
In order to increase vehicle flexibility and avoid the above mentioned drivers anxiety, but also maintaining urban delivery targets and electric operation during vehicle lifetime as well as reducing batteries weight and cost, range extender version specifications were fixed as following:
Considering the average speed of 14km/h, and considering that the energy consumption of this kind of vehicle is theoretical around 350 Wh/km, we estimate an average power of 4.9 kW.
After the tests performed on road, emulating the condition of the Hypothetic urban cycle, the results were an energy consumption, in electric mode, of around 360 Wh/km with an average power of 6.8 kW. The consequential electric range was 48 km.
This is a good value if we consider that , respect to the FUEREX demonstrator, on OPTIMORE demonstrator there is less embedded energy (only one battery pack); in fact , thanks to the new configuration with the Supercaps modules in parallel, the battery , working in a “comfort zone” , can guaranty to the complete system better performances and better efficiency than FUEREX.
During the test done in Hybrid/R.E. mode, although the hybrid capability implemented in the optimized range extender control SW on the AVMU control unit works properly, the RE fuel consumption and emission optimization were not completely in line with the targets: the optimization of the system calibration was not possible due to the sudden failure of APU inverter.
Anyway, despite the not optimized values of fuel consumption, with the fuel tank integrated on the vehicle (25 liters), it was possible to guarantee a R.E. range of around 207 km that is a value that can cover the ranges of the Hypothetic cycle:
52 Km for SUBURBAN CYCLE (≈60%)
33 Km for URBAN /DOOR TO DOOR CYCLE (≈40%)
On the other hand, as said before, the Pure Electric range, thanks to the new optimized ESS system, is completely achieved.
Cost, weight and volume optimization
To approach industrial sustainability, RE components have been improved and optimized in order to reduce costs, weight and volume.
The target weight reduction for REX was 20% together with a reduction of Range Extender length by 25% respect to FUEREX configuration.
The Optimore engine configuration starts from the Fuerex one, moving towards reducing cost and weight (industrial sustainability) and improving efficiency in real driving cycles: from this point of view the Optimore engine is a twin cylinder gasoline one, natural aspirated version. In fact a gasoline engine, if we include the fuel storage system, is much easier and lighter respect to the NG one and the availability of the fuel (gasoline) guarantees an easy capillary distribution of the vehicles.
Last but not least, the simplification of the engine implies an obvious cost reduction.
In the following table a comparison of the two different engine system configurations, in terms of weight, is shown:
The weight reduction in the Optimore configuration is around 50%, much higher than the target that was 20%.
The most important contribution to the weight reduction is given by the replacement of the CNG storage system with a standard gasoline tank. Another improvement is the weight reduction of the electric machine, thanks to the implementation of a different EM technology that allowed the design of a lighter machine. Concerning the length, thanks to the integration study of ICE and electric machine at mechanical level, the total length of the system is around 500 mm, taking to a length reduction of more than 30% respect to the FUEREX configuration
In conclusion, in terms of efficiency, the new E-machine compared to the Bosch E-Machine, seems to be less performing, but this is basically due to the absence of the permanent magnets in the rotor stack. In fact the Bosch E-Machine is a synchronous reluctance machine with internal permanent magnets (much more efficient especially at low rpm, up to the base speed), moreover the torque production capability is higher because of the even bigger active parts volume.
In fact the Bosch E-machine can provide up to 80 kW in overload condition, the new E-machine instead can provide up to 50 kW in overload condition.
At the same time the new E-machine is lighter, smaller and quite cheaper if compared to the Bosch E-Machine.
In order to reduce the technological gap between the two E-machines (our E-Machine has no permanent magnets) an innovative stator winding was designed and a customized rotor lamination was developed in order to make possible a direct drive installation with the ICE’s shaft. This solution made it possible to remove the mechanical interface between ICE and the Bosch E-Machine, with a large reduction of weight and size of the hybrid powertrain.
In the following table is summarized the comparison between the two E-machines:
In the first three columns is possible to find the comparison in terms of actual efficiency referred to a winding temperature of 100 °C . The gap is more evident at the lower speed, but this is just a peculiarity due to the two different types of E-Machine, in fact the permanents magnets give a substantial advantage in terms of torque production from the zero speed up to the base speed.
This gap is also due to the lower active parts volume (-32%); in fact the torque production capability is directly dependent on length and diameter of the active parts (at constant max phase current).
Standardization and modularization
For the standardization point of view we can state that:
- For the cooling system , respect to the FUEREX demonstrator, two normal production radiators have been used
- The HMI application implemented uses two standard Off-the-Shelf components and only the SW application has been customized.
- The battery package is a standard pack already used on Daily electric.
For the modularization point of view we can state that :
- The SW components implemented on the AVMU and on VMU allow to manage different configuration of the system and we would be able to change the number of battery of supercaps in order to fit the needs of different customer profiles.
- Also the modularity of the HW components used would allow us to change the vehicle configuration according different needs in terms of energy or power.
Demonstrator
The result of the final integration of the various components is:
3.2 Modular Electric Range Extender vehicle demonstrators
The VCC modular approach contains three different drivetrains which can be integrated into one electrified powertrain platform. It contains of a tunnel battery and an optional rear drivetrain providing different attributes and resulting cost.
Volvo C30 Electric have been chosen as a baseline, and the Optimore concept is a Parallel/Series hybrid. In addition to a pure series hybrid, the consumption during highway driving improves with drivability and performance.
Teh concept with the rear subframe contains the dual clutch transmission with the electric machine integrated in the gearbox. The subframe contains driveshafts within the same assembly and the engine mounts are similar as in Fuerex. The difference in this concept is that the movement of the rear powertrain will be larger, as because of pre-tensioning the drivetrain when transferring wheel torque. The Electric machine in the Optimore transmission is assembled on the even shaft axis.
The main results in consumption performance can be seen in Table 1 below. The concept itself fulfills the requirements for Euro 6 emission levels, although the prototype used in the project cannot fulfill these levels due to early prototyping material. In order to run the engine in efficient operating points, knock compensation need to be well calibrated to run efficiently. The higher sustain consumption in the Optimore concept can partially be explained by a spark retard at part-loads and the higher road load for the Optimore prototype than for Fuerex. This will also affect the emission results, why Table 1, Annex I, Part B could not be fulfilled fully within this project.
Table 1 Representing the Consumption performance of each concept where red values are representing simulated values and green are representing values measured within the scope of the Optimore project
C30 BEV C30 Fuerex Optimore
Results and Attributes Data Concept 1 Concept 2 Concept 3
Fuel Economy Fuelconsumption
@ 90 kph [l/100 km] 0 5,5 4,1
CO2 @ 90 kph [g/km] 0 128 97
CO2 NEDC depletion [g/km] 0 0 0
CO2 NEDC sustain [g/km] 0 166 183
Electric Range [km] 161 60 60
NEDC CO2 rating [g/km] 0 26 28
HMI Demonstrator and Work
The goal to find a non distrurbing ECO-Coach function started with case study what problems which occur related to limited electric range. This continued with analyzing the disturbance effects which can lead to limited electric range which are caused the driver. These disturbance factors which are related to the usage and driving of the car, have been the key focus information to distribute in a non-disturbing way. Also, a benchmark of the current market HMI have been carried out on already implemented competitor interfaces, to understand how they relate and affect the driving. One example is trees with growing leafs when driving efficiently and different type reward systems in the design. The focus in this project have been rewarding the driver driving efficiently by not displaying any information in order not to cause any distraction, different from the market today. The main driver related disturbance factors for electric range have been identified as:
- Driving too fast, road resistance increase with Air Drag
- Accelerating too hard, so the optimal efficiency of the drivetrain cannot be achieved
- Braking too hard, with saturated electric recuperation and engaging friction brakes
Also, a guidance range meter was implemented to feedback how the electric range is affected by the road load polynomial. In this way, one would know which Eco-speed to aim for to avoid engine starts when driving towards a destination.
3.3 City Electric Vehicle demonstrator
The targets of this WP were; To optimise the system layout, To improve the hardware and to industrialise the software, To reduce the cost and To optimise the whole system based on the detailed development.
The system layout of the city car was optimized based on real world conditions and the experience of the previous project FUEREX regarding drivability, fuel consumption, emissions, cost and NVH:
- by associated REX operating strategy, driven by State of Charge requirements
- Thermal management under real-world conditions for the optional use of electric energy and/or waste heat generated in the RE unit
- Comfort demand combined with the technical thermal management of the power train and the impact on efficiency, durability and emission
The hardware and SW were further developed by
- Eliminating of expensive (prototype) materials and processes,
- Improved aftertreatment functionalities,
- Evaluation of different design solutions to improve packaging and NVH,
- Developing next level of power electronics regarding automotive requirements, volume and weight reduction.
The SW industrialization was concentrated on functional safety, comfort features and integration into operating software which finally represents a solid base for further specific applications:
- Development and testing of fail-safe procedures for the charging process
- Integration of optional communication to the charging infrastructure
- Safe start procedure for control units and proper initialization sequences
- Integration of air conditioning and heating strategies
- Optimized creeping mode for low speeds in city operation
- Redundant control algorithms on vehicle and engine control unit for error detection and recognition of shutdown or limp home conditions
- Variable recuperation modes on driver demand
- Development of range extender multi-point operation for flexible adaptation
- Implementation of emission relevant functions like charcoal-canister purge
The development was based on the Control Units and the E-Vehicle architecture.
The cost reduction of the Range Extender under reliability aspects addressed:
- Evaluation of well-known volume production materials and technologies for the use in the rotary engine production.
- Beside cost reduction on component level, various sub-systems were simplified or combined to reduce complexity and weight.
- The cooling/heating system of the ICE, aftertreatment system, E-motor and battery regarding hardware, operating and control strategies were optimized.
The production cost assessment was performed for the range extender unit incl. exhaust system for two different production scenarios:
Scenario 1: Volume: 20.000 units/year, OEM production, brownfield approach
Scenario 2: Volume: 100.000 units/year, Tier 1 Supplier for different OEM’s, brownfield approach
The system optimization was performed under two main aspects, the legal NEDC test cycle and representative load profiles for EVs. The operating point of the range extender has a high influence on NVH behavior in the vehicle especially under low speed conditions at city driving. This aspect was optimized once again with the final performance of the range extender in the vehicle. Based on these criteria the durability aspects are of minor priority at real live conditions.
The final results of the rotary range extender are shown in Table 2. Compared to the project targets the NVH behavior, the weight, and space targets were fulfilled, while the cost targets can be kept at a production volume higher than 100.000 units per year. The specific fuel consumption is app. 5 % higher than the target value, the emission level at NEDC is at 65% of EU6 (target was 50 %). The reasons for that are the HC emissions.
The final integration of the Wankel Range Extender into the city car with the targets; excellent driveability, excellent NHV behaviour and no constraints of the passenger compartment and car boot were achieved.
The vehicle concept provides an electric range for average daily need of approx. 50km with a high voltage battery of 12 kWh. The battery management is designed for an energy and power reserve required for full dynamic vehicle performance. The vehicle is equipped with an electric motor of 75kW & 240Nm peak torque, the energy consumption will be 16kWh/100km, and the fuel tank size is dimensioned for 250km total range. The fuel consumption of 1.8l/100km is measured under real driving conditions at daily use in a timeframe of March 2014 to October 2014.
Important for the electric driving range are the load profile, heating in wintertime and air conditioning in summer time. The lower the average speed the more negative impact of heating and air conditioning appears. Whereas the electric operating range is decreasing by 40 % in the NEDC cycle due to air conditioning, in the New York City Cycle the electric operating range is shrinking by app. 60 %.
3.4 Functional Safety Development
Motivation and Achievements:
In the course of the OPTIMORE project co-funded by the European Commission, AVL-SCHRICK developed a complete generic functional safety concept applicable for range extender electric vehicles (RE-EVs). It was created to be used as a baseline for all functional safety and system level FMEA work packages in RE-EV production programs for the OPTIMORE project partners and AVL-SCHRICK itself.
The generic functional safety concept is developed based on the methodical and structural principles described in the ISO 26262. According to the definition in this standard, the following set of documents was created:
- Generic Item Definition for RE-EVs
- Generic Hazard and Risk Analysis for RE-EVs
- Generic powertrain system FMEA for RE-EVs
- Generic Functional Safety Concept for RE-EVs
Generic Item Definition
For the creation of a generic item definition for range extender electric vehicles (RE-EVs), the following steps were executed by AVL-SCHRICK:
Definition of a generic RE-EV powertrain architecture applicable for the target vehicles of the OPTIMORE partners and also for other RE-EV applications.
Definition of the main functionalities of the generic RE-EV powertrain and allocation to a responsible hybrid powertrain component / control unit.
Definition of the system boundaries for the functional safety development. The system boundaries indicate which components are taken into account completely for functional safety development and which interfaces to environmental components have to be considered. The boundaries are illustrated in a generic system boundary diagram showing all identified powertrain components and the respective internal and external component interfaces.
Definition of the high voltage circuitry. As the HV storage system and the corresponding consumers and circuitry are highly critical in terms of safety development, a generic HV architecture including all HV components, switches and wiring for RE-EVs was defined and agreed.
Detailed definition of RE-EV functionalities including boundary conditions, function sequence and functional allocation to target controller. For each function the trigger conditions, a description of the function sequence and the exit conditions were identified. Each sub-task during a function was allocated to a designated target controller which is responsible to control and monitor the respective task.
Identification of RE-EV operation scenarios as input for Hazard and Risk Analysis (HRA). The final part of the Item definition contains a collection of operation scenarios for the RE-EV including the type of streets, the traffic situation, the driving situation and the environmental conditions.
Generic Hazard And Risk Analysis
On the basis of the item definition, a generic Hazard and Risk Analysis (HRA) was created and agreed with the OPTIMORE partners applicable for all RE-EV concepts. In the HRA, a rating of possible malfunctions of the defined functions was done under consideration of the driving situation and environment as defined in the item definition. The generation of a HRA is divided in two different phases:
- Preparation phase with collection and structuring of required inputs from item definition, generic databases and other sources.
- HRA session phase with common workshops to identify hazards, discuss their ratings and to derive respective safety goals.
Altogether, 73 hazards were identified, described and evaluated for generic RE-EVs. The rating for Severity, the Exposure and the Controllability for each failure mode was executed according to ISO 26262 methodology. Composed out of these three ratings, an overall safety level was calculated (Automotive Safety Integrity Level – ASIL):
40 hazards rated with QM
17 hazards rated with ASIL A
11 hazards rated with ASIL B
2 hazards rated with ASIL C
3 hazards rated with ASIL D
For all hazards with ASIL higher that QM, a safe state was determined and described in the safety goal as input for the functional safety concept.
Generic Powertrain System FMEA
A generic powertrain system FMEA was created based on a generic RE-EV architecture and related functionalities as agreed with the OPTIMORE partners in the RE-EV Item Definition. The FMEA identifies countermeasures on (sub-) system and component level to prevent powertrain failure modes with high severity. The approach for creation of the FMEA was the following:
- The systems and components of the RE-EV powertrain are identified and assigned to the levels powertrain level, (sub-) system level and component level. Each component is linked to the related system and the powertrain.
- The main functions for the powertrain systems are identified.
- For each system and each related function, potential failure modes are identified which compromise the functionality of the system or the passenger safety.
- For each system failure mode, potential effects on powertrain level are identified and rated concerning their severity. The rated severity is cross-checked with the results of the HRA to ensure the quality of the functional safety work.
- For each system failure mode, potential causes on component level are identified.
- For each failure mode on component level causing effects with high severity (≥ 7) at powertrain level, preventive actions and detection actions are defined.
As a result, a large list of preventive and detection actions for each component of the RE-EV powertrain was created describing measures to increase the robustness of the system and to prevent critical failures with potential impact on RE-EV driver and environment safety. The list includes more than 500 actions assigned to the different components.
Additionally to the already specified countermeasures, the output of this powertrain system FMEA can be used as in input for the component FMEAs to be done component suppliers in vehicle series development programs.
Generic Functional Safety Concept
Based on the previous functional safety tasks (creation of item definition, preparation of hazard and risk analysis) a generic function safety concept (FSC) was created applicable for generic RE-EV architectures and related functionalities as agreed with the OPTIMORE partners. In the FSC all identified safety goals of the HRA were derived in functional safety requirements and allocated to the elements of the relevant safety architecture concept.
The applied approach to develop the Functional Safety Concept for generic RE-EV architectures in the OPTIMORE project is composed in the following steps:
- The safety goals with the assigned ASIL levels and the safe states identified in the hazard and risk analysis are the basis for the derivation of functional requirements in the FSC. The safety goals coming from the HRA are combined to ten safety goals in the FSC. The highest ASIL rating of the HRA safety goals is applied to the safety goal in the FSC.
- If applicable, a decomposition of the ASIL rating according to the regulations as defined in ISO 26262 is done (applied on one safety goal).
- For each safety goal, at least one functional safety requirement is defined.
- Each functional safety requirement is allocated to the related architectural elements of the item.
- For each functional safety requirement, a safe state is defined.
- For each functional safety requirement, a fault tolerance time is defined.
- For each safety goal, a safe state is defined (considering the safe state of the functional safety requirements).
- For each safety goal, a fault tolerance time is defined (considering the fault tolerance time of the functional safety requirements).
- If applicable, additional requirements safety instructions are defined (warning concept, etc.).
For the ten identified safety goals, in total 71 safety requirements were defined to be applied to the different components of a generic RE-EV powertrain.
As a results of the functional safety concept, the final step of the functional safety investigation for RE-EV concepts, a large number of generic requirements has been defined, discussed and handed over to the OPTIMORE project partners. The defined requirements shall be used by the partners as a baseline for their own functional safety process in order to shorten the time-to-market of their respective vehicle. At the same time, the results are also used by AVL-SCHRICK to strengthen their market position as engineering partner for RE-EV solutions by reducing the effort and time and thus cost during respective development programs.
3.5 Optimization of range extender, battery size and control for different vehicle niches
In this section the main results concerning the objectives in Section 1 are described.
Optimal battery size
To illustrate the methodology developed, a real world movement database with more than 400 drivers is used.
The data describing the drivers can be described by a density function f(x) which equals the fraction of trips by this driver of length x. The total number of trips is indicated by T. The vehicle is assumed to be re-charged after each trip. The main variables to be considered in the sizing are the battery size, described as All Electric Range (AER) with price C_batt per kWh, the distance the vehicle can drive electrically, and the range extender size. The energy costs, fuel and electricity are indicated by f_km and e_km, respectively. Using this notation, the Total Cost of Ownership (TCO) as a function of AER is expressed by the relation.
(for the equations, please refer to the pdf file including)
This is the fundamental relation used for all investigations concerning the sizing of components, the dependency on the drive cycles, the sensitivity of the sizing etc.
When computing the optimal battery size for the 400 drivers contained in the database and grouping them in vehicle niches is easier to visualize which drivers are group together. For the case one wants to offer three battery sizes and a conventional vehicle to this group of drivers.
This also illustrates the sensitivity of the optimal choice by changed conditions by how much the intersection change. Other measures of sensitivity, for example, how much TCO change for the individual drivers due to changes, eg, if the fuel price change, has been investigated based on the relation of TCO. All these results can nicely be illustrated in figures.
Smaller Range Extender Size
The normal energy management strategy for RE-vehicles is to use the cheap electric energy first and start the RE when the battery is empty which happens if the trip is longer than the AER. This is called Charge depletion charge sustaining (CDCS) strategy. If the driving distance is known in advance, a not unrealistic assumption, Blended Charge Depletion (BCD) is an alternative where the battery and the RE are used in parallel during the whole trip and this makes it possible to downsize the RE without reducing the performance of the vehicle. This is shown here in an example where the required RE power to complete motorway driving cycles of different distances are compared.
Motorway driving is represented by an Artemis motorway driving cycle. The battery size in this example is of 14kWh battery, which allows for approximately 47 km AER in an Artemis Motorway driving cycle. The RE sizes needed as well as the depending on maximum trip distance.
Several conclusions can be derived:
- The RE size for CSCD mode is independent on the distance of the driving cycle. It only depends on the average power demanded in the CS part of the driving.
- The reduction in RE size when driving in BCD mode is proportional to the ratio between the driving cycle distance and the AER of the vehicle.
Another criterion for sizing of the range extender is performance during climbing, Table 4 shows the extra energy needed from the battery in order to climb 1000 meters with a 25 kW RE but maintaining the performance level of a 35 kW RE. Hence, as long as this energy is available in the battery before the slope, the 25 kW RE has the same performance as the 35kW RE.
1000 meters climb at: CSCD Mode BCD Mode
120 km/h-2% slope 35 kW 25 kW + 2.74 kWh
100 km/h-5% slope 35 kW 25 kW + 2 kWh
70 km/h-10% slope 35 kW 25 kW + 1.58 kWh
Table 4. Extra energy from the battery to climb 1000 meters when downsizing the RE power from 35 kW to 25 kW.
If the vehicle is able to anticipate and save that extra energy in the battery a 25 kW RE could offer similar performance than a more expensive, heavier 35 kW RE.
Charging the battery with RE power will be possible in many driving situations. Driving the vehicle in an Artemis motorway driving cycle a 25 kW RE is able to recharge 2kWh into the battery in around 18 minutes, and if the vehicle is driving a less power demanding rural environment (Artemis Rural) the same 2 kWh can be charged into the battery in just 10 minutes.
A 35 kW RE would cost around 2800€ while the cost of a 15 kW RE would be in 1500€ level. Assuming a linear dependency between power and cost a 25 kW RE would cost approximately 2150 €, which represent 650 € savings from a 35 kW RE.
Potential Impact:
4.1 Expected impacts listed in the work programme
The OPTIMORE project contributes to the expected impact listed in 7.2.7.THE ‘EUROPEAN GREEN CARS INITIATIVE’ under the topic Research on electric and hybrid vehicles
GC.SST.2012.1-5 Integration and optimisation of range extenders on Electric Vehicles
Although Electric Vehicles are able to cover almost 80% of average travel needs, the residual need of many vehicle users for occasional longer distance travel means that range-extended electrified vehicles provide an important path towards increasing the market penetration and customer acceptance of electrified vehicles, by relieving the so-called “range anxiety”..
The focus of the research will be on developing and optimising the concept of the fully-integrated, range-extended, electrified light duty vehicle which will offer both significantly reduced impact on the environment and long range capability. The aim is to optimise the integration and control of the electrified vehicles equipped with a range-extender while ensuring that the range in pure-electric mode, typically charged using the grid, is sufficient to cover average daily mileage.
The activities should address the following issues:
• Optimisation of the ICE used as the range extender and of its after treatment system.
• Impact on optimal battery capacity.
• Advanced control strategies.
• Modularisation.
• Performance, safety, recyclability and cost.
• Characterisation, standardisation and synergies with other applications.
• Existing engines from other applications potentially well adapted to the range extender role
4.1.1 Why introducing Fully Electric Vehicles (FEV)?
To achieve a sustainable transport sector the net CO2 emissions from fossil fuels must gradually be eliminated. Already by 2020 a significant reduction must be reached, but that is not enough and the net CO2 emission must continue to be reduced completely during this century. To achieve this non-fossil energy sources must be used. The main sources available are fuels from biomass, hydrogen from renewable sources or electricity from wind-, hydro-, solar- or nuclear power.
Bio fuels are a technically feasible option, but there is a competition for the biomass resources from many sectors in society, like food, energy and feedstock for the industry. The potential for sustainable biomass production is far too small to meet all the demand for it. Therefore the biomass will be used by the sector, which is prepared to pay most for it and recent studies indicate that this will mainly be the food sector, parts of the stationary energy sector and a feedstock for industry. Vehicles will most likely be rather run on electricity, for cost reasons. It is also likely that bio fuels will be used in some special parts of the transport sector that cannot be electrified, like air and sea transport, special vehicles and some part of the long haul transports. Renewable electricity will most likely also be a scarce resource for many years to come, but in comparison with biomass it is likely to be both cheaper and more easily produced in large quantities.
Hydrogen is also a competitor to battery electric vehicles, and then mainly as fuel cell hydrogen vehicles. It is a technology which is more difficult to draw certain conclusions about. Hydrogen will in many respects be comparable to electric vehicles in that they will also be quiet, no toxic emissions and no CO2 emission from the vehicles. However, the main drawback of hydrogen lies in the need for a completely new infrastructure for hydrogen supply. When it comes to cost for the energy the picture is not fully clear, but it seems likely that electric energy can be produced at a lower cost, at least in the short to medium term perspective.
Electric cars are quieter, cleaner and cheaper to run than cars equipped with an Internal Combustion Engine. Below, in a nutshell, are a few key benefits of electric cars:
1. Electricity is cheaper than gas, a difference which is likely to increase as oil becomes a scarce resource, and can come from renewable resources such as solar and wind power.
2. Electric cars pollute less than gas-powered cars (especially when renewable energy sources are used to generate the electricity).
3. By using domestically-generated electricity rather than relying on foreign oil, we can achieve energy independence.
4. Electric cars can utilize the existing electric grid rather than require the development of a new, expensive energy infrastructure (as would be the case with hydrogen).
4.1.2 Why Electric Vehicles with a Range Extender and projected impact of OPTIMORE
As mentioned before, there are many benefits for an electric vehicle. So why have they not yet been fully adopted?
The introduction of electric vehicles is delayed by several problems of the chicken or the egg type:
• Electric vehicle are too expensive and therefore almost non existing, due to the battery price – Batteries are too expensive due to the low volume of production.
• Electric vehicles require a charging infrastructure with high coverage in order to be attractive – Building a charging infrastructure is only attractive once there are many electric vehicles that pay to use it.
• The limited range of the electric vehicle is a problem since the batteries are expensive and heavy. – Once electric vehicles are the standard solution the short range is less of an issue since charging infrastructure will be available almost everywhere.
Range extender vehicles will be the important evolution step which enables the unlocking of the above mentioned lock-in mechanisms. This is enabled since the range extender vehicles allow:
- Reducing the battery costs for the consumer: since the range extender makes it possible to size the battery only for the typical driving distance rather than for the occasional long distance trip. As a result, the batteries cost for driving this vehicle will be much lower than an EV without a REX.
- Charging of the batteries: due to the fact the REX is available charging the batteries is not a crucial issue anymore and the advance planning for the use of the car will be much less crucial. Still the drivers will normally use the available charging stations and thus creates market demand that encourages a continuing expansion of the charging infrastructure.
- Limits on driving distance: Most of the electric cars have limits on how many miles they can go before needing a recharge. The REX solves this issue by allowing a small and cheap battery which is often used to its limit in order to maximize electric driving range. The range extender provides the confidence to do this, while it will still only be used for a rather small part of the total driving range of the vehicle. As the range extender vehicles will have created a “critical mass” for battery volumes and charger infrastructure, the fully electric vehicle will gradually be able to replace many of the REX vehicles as the batteries become cheaper and have higher energy density, and with growing possibilities to charge almost anywhere.
Also, one of the biggest problems for pure-electric vehicles is not just the driver’s ‘range anxiety’ but also the huge draw on battery power required by lights and heating in winter. Cold weather also wallops the battery’s performance. It is not foreseen that these issues are being solved on the short term. The EV has a promising future but it will be at least a decade away for electric vehicles breaking through into the mass consumer market. However, the ultimate goal will be to have a fully electric vehicle.
The Electric Vehicle with REX provides the opportunity to tackle the above mentioned issues. And also important, it provides the opportunity to anticipate the foreseen developments relative to a 2011 battery:
• Improvements of 20 to 25% in specific energy with a similar reduction in cost by 2016 primarily due to improved battery design and packaging;
• Improvements of 70 to 75% in specific energy and 50% reduction in cost per kWh by 2020 to 2022 with the introduction of advanced materials for the anodes and cathodes, such as silicon anodes;
• Potential for a tripling of specific energy and 70% cost reduction per kWh by 2030 with the introduction of lithium-sulfur batteries;
The current costs of lithium batteries are based on battery manufacturer quotations to car manufacturers at rates of about 20 thousand per year for supply starting in 2011/2012. Future costs to 2020 and 2030 are based on using current cost numbers and accounting for effects of volume, scale and in the case of the battery, new technology, as shown below.
The key about combining a petrol engine/generator and battery pack is that it can deliver the performance of a big internal combustion engine along with very low emissions of both CO2 and pollutants.
Battery cost and size mean that all-electric cars still have a relatively limited operating range. With the range extender, the electric car has its effective range increased by a thousand kilometres - yet with the average carbon dioxide emissions below or way below 50 g/km.
OPTIMORE’s contribution to solving the problem
As explained, the electric passenger cars that are currently being developed are not yet competitive with conventional vehicle technology and do not meet the customer needs to a large extent. Three Fully Electric Vehicles (FEV) equipped with range extenders will demonstrate the largest potential to meet the customer demands in terms of efficiency, NVH, fuel type, exhaust emissions, dimensions, weight and costs. The three concepts are:
a) City compact Electric Vehicle, equipped with an innovative rotary engine for medium term (2020+)
b) A family (medium passenger) of new Electric Vehicle either as FEV or EV-RE equipped with a 3 cylinder piston engine (VCC/AVL-Schrick) used in a modular way, based on customer demands and their needs on the short term (2020+)
c) Light commercial Electric vehicle, equipped with a 2 cylinder piston engine (CRF) optimised for weight and costs with an application on light Commercial vehicles on the short term (2015+)
OPTIMORE delivers solutions for both short and medium term that have large impact in terms of volume (market segments and number of vehicles) and ecological footprint (reduced (CO2) emissions, well to wheel efficiency, optimised weight and costs, etc.). The developed range extender concepts are expected to be very competitive both in comparison with battery electric vehicles but also in comparison with plug-in hybrid vehicles with a more traditional ICE power train, and thus they have the potential to be the main solution for passenger cars in the medium term perspective.
Economic impact of OPTIMORE
Optimore will reduce the dependence on oil and to reduce emissions. With the global requirement to reduce CO2 emissions driving a move to the increased electrification of the vehicle, the realities of economics provide a serious challenge for electrical cars.
Although OPTIMORE has its focus on the application in battery electric vehicles with range extenders rather than on plug in hybrids, there are many similarities between range extenders for battery vehicles and plug in hybrids.
It is therefore safe to say that OPTIMORE has an impact in accelerating the sales in both EV and PHEV markets with a focus on sub-compact passenger cars and light duty commercial vehicles. The reason for focussing also on this particular segment is the expected dramatic increase of freight transport inside high concentration urban areas during the next decade. For its specific mission profile this kind of vehicle can, of course, get the maximum benefit from the electric driving mode (noise, vibration, pollution, frequent stop&start situations) while the Range Extender approach will supply a higher flexibility in terms of fleet management.
Market introduction of RE-BEV’s will be accelerated directly by the OPTIMORE auto manufacturers Volvo Cars and the FIAT group (represented by IVECO) but also through the RE engine manufacturers in the AVL group that will supply other car manufacturers with integrated RE solutions. Obviously, both exploitation routes will have beneficial effects on Europe’s automotive industry in terms of competitiveness and employment.
Environmental impact of OPTIMORE
In Europe, the European Union is committed under the Kyoto Protocol to reduce GHG emissions by 8 per cent by 2008-2012 compared to the 1990 level. In addition, the EU has committed to a 20% cut in its greenhouse gas emissions by 2020. The EU has also adopted a target improving energy efficiency in the European Union by 20% by 2020.
The OPTIMORE concepts meet these targets and even more important the project will address all main obstacles for developing successful electric vehicles and thus play a major role in the greening of the transport sector in Europe. Not only are electric vehicles more efficient in their use of energy, they produce no direct greenhouse gas emissions. There is also an indirect effect of introducing low CO2 emission vehicles, since they make buyers aware of the possibility to lower the fuel consumption even further. The introduction of hybrid vehicles triggered a significant improvement of the fuel consumption of traditional ICE power trains, and it is likely that the introduction of Range Extender vehicles with an attractive performance will increase the customer demand also for other sorts of low fuel consumption vehicles.
In the environmental comparison of conventional BEV’s and RE-BEV’s, another important issue related to the battery mass is worth mentioning. The specific power density of a battery system is in the range of 0.1kW/kg thus a nominal range (extension) of 100km requires an additional battery weight of 150 – 200 kg, which is equivalent to a surplus in fuel demand 0.4 to 0.8L /100km in customer duty. The range extension by a range extender engine has a much lower weight penalty for common customer range requirements leading to only a minor fuel consumption penalty relative to an urban area BEV with a range of 50km only.
4.1.3 Added value of a European approach
The aims of OPTIMORE can be best achieved by addressing the research at European level rather than at national or private level. The main reasons are the following:
• Car manufactures and (first tier) suppliers are operating/acting on a European (even world wide) scale rather than a national scale;
• Greening of road transport and in particular Electrification of the vehicle fleet is a European and even global issue;
• Reducing the emissions in road transport is a major societal concern common to all European countries and it requires a sustained effort at European (and global) level to achieve significant improvements;
Moreover, the initiation of OPTIMORE at European level enables to bring together partners with excellence in necessary fields of expertise, which are not adequately available at national level. The OPTIMORE consortium fits together perfectly to find system solutions as the basis for future customer programmes and products meeting these targets. It brings together engine specialists (AVL, CRF), major auto manufacturers (Volvo Cars and the FIAT group represented by CRF and Altra), and scientific excellence in the fields of combustion engine technology, hybrid vehicle technology (Chalmers) and alternative fuels (AVL and Chalmers).
4.1.4 Contributions to standards and regulations
There is a need to standardize driving cycles for vehicles with range extenders, to enable efficient ways of calculating relevant figures for emissions and fuel/energy consumption. The work within OPTIMORE will contribute by describing important aspects of the driving cycles. However, it is not a primary goal of OPTIMORE to define standard drive cycles as it is expected that standards will not be defined until there is significantly more experience with range extender vehicles on the European roads.
4.1.5 Collaboration with other (inter)national research activities
Collaboration is foreseen with Coordination Action ULYSSES (The future propulsion as one system) and the large-scale collaborative project HI-CEPS (Highly integrated combustion electric powertrain system), belonging to the CA ULYSSES, both led by CRF. The research done in FP7 project FUEREX will be used as a basis for OPTIMORE.
The Chalmers research on system analysis/control and combustion engines is carried out in close cooperation with research on related topics within several national Swedish programs.
4.1.6 External factors that may determine whether the impacts will be achieved
Electric-drive vehicles are unlikely to succeed in the next five to ten years without strong policy support (governmental/tax incentives) in the area of making vehicles cost competitive with today’s internal combustion engine (ICE) vehicles. Moreover, cost competitiveness will depend highly on future electricity and oil prices, and consumer willingness to pay extra for EVs compared to similar ICE vehicles. . Battery cost is the main bottleneck and, hence, a break-throw in battery technology lowering this cost would of course change the future map drastically in favor for electro-mobility in large.
4.2 Dissemination and exploitation of project results, and management of intellectual property
4.2.1 Exploitation of project results
Because of the consortium’s constitution along the value chain, the partners of the OPTIMORE project will together handle all exploitation related activities and IPR-issues.
Exploitation route
According to the ERTRAC road map , the future introduction of Electric Vehicles in the market will very strongly depend on the availability of functioning and cost efficient products from the suppliers. In their view, low-cost/weight motors and electronics should be available by 2012. Followed by optimized combustion engines for range extenders and highly integrated motors & controls by 2016. As the last milestone, mass production of highly integrated range extender systems should be a fact by 2018-2020.
Due to the fact that OPTMORE builds upon the FP7 FUEREX project, it’s work programme could very well run ahead of ERTRACs’ schedule, bridging the gap between milestone 2 (intermediate) and milestone 3 (mass production), herewith significantly supporting the early-market readiness of BEVs.
Exploitation interests partner group
Interest OEM partners [VOLVO, IVECO]
In December 2008 a new law was adopted: the new law nominally strives to reduce the average CO2 emissions from new cars to 130 g/km by 2015. Significantly the law adds a 95 g/km target for 2020, the “modalities” and “aspects of implementation” of which will be reviewed by the Commission in January 2013.
Carmakers are responsible for delivering the reductions. The company target is an average for all cars sold, not a fixed limit that no car may exceed. In this scenario, automotive manufacturers must seek and provide improved and innovative vehicle solutions to the open market which are not only compliant with the energy and environmental conditions and with the new law requirements, but also be competitive and increasingly appealing. In other words all the main global OEMs, including those based in Europe, are essentially being forced into finding new technological solutions to respect the social and environmental needs (environmental friendly vehicles) on one hand and on the other meet the demands of the customer (like higher levels of driveability and comfort, better safety and styling) at acceptable costs (in terms of purchase and operation costs as the price of fuel continues to increase).
Volvo and IVECO are committed towards meeting the targets for fleet average consumption of vehicles in Europe by 2020. One of the key technologies needed for this is electrification of vehicles as it shifts the propulsion system from fossil fuels. The reduction of European CO2 emissions is naturally dependent on the matter in which the electricity is produced. However, assuming a fossil free production of electricity this is a huge step forward. The successful introduction of electrified vehicles is strongly connected to the cost. Therefore Volvo and IVECO strongly believe that finding the right balance between battery capacity and range extender power is a key to finding the right cost. Modularity of the product is also a key to cost optimising the product. This is also one of the outputs from this project. The OEM partners will use the findings of this project to optimise the vehicles for maximum energy efficiency as well as cost in order to deliver an attractive product to the customer.
Interest supplier partners [AVL, Getrag]
The main interest of AVL is to sell leading engineering services and technologies especially to European Tier1 suppliers or OEMs which help to reduce CO2, emissions and NVH levels to comply with future legislation.
The service portfolio of AVL includes component, system development and software engineering. The rotary range extender and therewith OPTIMORE is a flagship for AVL regarding E-mobility. It is covering the integration of conventional technology with future key E-mobility elements to lower emissions at maximum in urban areas and to lower CO2 emissions generally as an enabler for E-vehicles in a wide application field. Currently it is a potential demonstration, 2015 the technology will be available for mass production, 2018 to 2020 the vehicles with highly integrated systems should be on the market. This business plan of AVL fits very well to the ERTRAC roadmap.
Interest knowledge providing partners [Chalmers, CRF]
CRF foresees different possible levels of exploitation concerning the Range Extender pack. The envisaged architecture is suitable not only for the specific application on BEV commercial vehicle, but also for other possible synergic utilizations that are concurring for the cost/volume industrialization targets; of course further exploitable results can be delivered during the progress of work. In the table below the plan is summarized (all generated in WP2):
Exploitable knowledge (description) Exploitable product(s) or measure(s) Sector(s) of application Time for commercial use Patents or other IPR protection
Specific management strategies Dedicated strategies integrated in the ECU RE pack tailored for small size Passenger Vehicles 2015 Pre-existing patents and patent application (CRF)
RE pack architecture Integrated Optimized Range Extender pack 1- Micro CHP (Combined Heat & Power) for off - road applications – i.e. industrial and domestic.
2- Series Hybrid for mid-High Size Passenger Vehicles 2016 Pre-existing patents and Patent applications (CRF, MM-PWT)
For universities the project should lead to the development of new insights and knowledge in several areas which will increase our innovation and development capacity. The new knowledge generated will be translated into new research ideas/projects but also used in education of PhD’s and Master students.
Chalmers has selected Transportation and Energy as two of its eight areas of advance and sustainable development as an overall focus, and this will means that the results from OPTIMORE will be used in a large research network.
• Swedish hybrid vehicle centre: Hosted by Chalmers and including the three Swedish vehicle OEMs and five universities.
• Combustion Engine Research Centre: a competence centre dedicated to development of environmental friendly and efficient combustion engines, including both university and industry.
• The Energy area of advance which include Hybrid and electric vehicles as one of the research themes.
Because of these networks, the results from OPTIMORE will be used by OEMs and researchers developing vehicles, but the knowledge will also be spread to researchers involved in other areas where the development of the vehicles is not the main focus but where understanding of the possibilities with range extender vehicles may be of importance for guiding their research and development. These other areas where OPTIMORE results may be very useful can be for instance life cycle studies of new transport solutions, development of recycling, development of new fuel and energy supply, Vehicle safety research or development of global energy and resource models.
The project has also generated good engineering examples which will be used in teaching. In this way, general engineering methodology can be covered at the same time as relevant environmental important aspects are covered.
4.2.2 Dissemination and exploitation
Within the Dissemination and Exploitation work package several deliverables are achieved in the first period, mainly setup of dissemination tools. The second period of the project was the execution of the dissemination activities and the monitoring of the exploitable results.
Public website
www.optimore-project.eu the project website was initiated at the beginning of the project and all project (public) results are available on the website.
(Peer) reviewed articles
From the results of the OPTIMORE project are in total six articles created and accepted by several journals and publishers.
The abstracts of these articles can be foud following the below link. Also included are the links to the publishers where the articles can be downloaded or purchased (if not free available).
http://www.optimore-project.eu/articles/peer-reviewed-articles.html
Flyer, Newsletters and other dissemination material
In total three newsletters are created from the project.
The first newsletter in the form of a general Flyer and distributed to all relevant stakeholders, using the dissemination database. The flyer is also published on the website as news item and under downloads.
The first newsletter was released after period 1. The newsletter was sent as an html mailing via e-mail and with reference to the downloadable items on the OPTIMORE website.
The second newsletter was released after the completion of the project and contains the following items:
- Final results, split into the 3 demonstrator vehicles and the results on the optimisation study from Chalmers and the functional safety. Short description in the newsletter with a reference and link to the more extended description on the public website
- Listing of all publications resulting from the research in the project
- Link to all deliverables from the project
- Results from the FINAL event
Further dissemination achievements
Final Workshop at Volvo
The final workshop was arranged in a two day workshop, with the first day afternoon an overview of all results from the OPTIMORE project followed by an evening event to further discuss the results. The second day was a gathering at the Volvo driving test track in Gothenburg, where the invited guests and the project partners could “experience” the driving in electric and electric Range Extender vehicles. Followed by a short workshop where the feedback from the participants was collected to further improve Range Extender vehicles in the near future.
Internal dissemination at OEM level
Within VOLVO/CRF/IVECO, the information was shared with relevant people in the design & test engineering departments in Europe, to evaluate how the outcome of the project could be implemented and be used to introduce OPTIMORE technology in Electric Vehicles across Europe and beyond.
List of Websites:
www.optimore-project.eu
Worldwide, there is a strong trend towards highly efficient, low (preferably zero) emission vehicles, i.e. electrical vehicles. Electric Vehicles are able to cover almost 80% of average travel needs. However, many vehicle users require occasional longer distance travel capabilities of their vehicle. To relief this so-called “range anxiety”, there is a need for advanced plug-in hybrids and electrical vehicles with range extenders for regular customer duty. For this purpose, highly efficient, compact, clean and low cost engines are developed in this project OptiMoRE. Three different RE concepts of OPTIMORE will be developed and demonstrated to serve the niches from city vehicles over medium sized passenger cars up to light commercial vehicles.
The CONCEPT of OptiMoRE is based upon the following major elements:
1. Definition of real world driving conditions (driving cycles and comfort requirements) as a baseline for further optimisation and EV assessment
2. Optimisation of components and the whole RE system regarding emission, fuel consumption, cost, weight and exhaust gas after-treatment
3. Modular setup of an EV concept to fulfil a wide range of customer expectations
4. Advanced control strategies as a key for cost reduction and system optimisation
5. Functional and Electrical safety analysis and concept development to define measures necessary according to the ISO 26262 standard
6. Build-up and optimisation of three technology demonstrator vehicles covering EV aspects for delivery trucks, all-purpose vehicles and city cars.
The main results achieved can be described as follows:
A Commercial Vehicle moving to efficiency in real driving cycles and approaching industrial sustainability is developed, build up and demonstrated and an overall weight reduction of the RE unit is 126 kg (approx. 50% reduction) compared to FUEREX is achieved. Further, the vehicle defined three main working points for the Range Extender: 20, 15 and 10 kW of electrical power at battery terminals.
The second demonstrator is achieved: the Modular Electric Range Extender vehicle. The Volvo passenger car modular approach contains three different drivetrains which can be integrated into one electrified powertrain platform. It contains of a tunnel battery and an optional rear drivetrain providing different attributes and resulting cost. The concept itself fulfills the requirements for Euro 6 emission levels. Within the RE development also the Human Machine Interface (HMI) is closely examined to find a non distrurbing ECO-Coach function started with case study what problems which occur related to limited electric range. The new HMI concept is implemented in a demonstrator vehicle.
The City Electric Range Extender Vehicle was optimised in the system layout, improved in the hardware and the software was industrialised. This all with the aim to reduce the cost and to optimise the whole system based on the detailed development. The final result was a demonstrator vehicle fully functional and operational.
Next to the three demonstrator vehicles, a functional safety development took place and resulted in the generic functional safety concept and is developed based on the methodical and structural principles described in the ISO 26262. According to the definition the following set was created: Generic Item Definition for RE-EVs, Generic Hazard and Risk Analysis for RE-EVs, Generic powertrain system FMEA for RE-EVs and Generic Functional Safety Concept for RE-EVs.
The final achievement was the development of an Optimization routine for Range Extenders, battery sizes and controls for different vehicle niches. The theoretical study was assessed and evaluated based on real drive cycles and drive missions, collected in a database in Sweden. The definition of real world driving conditions (driving cycles and comfort requirements) was achieved as a baseline for further optimization and EV assessment. This is based on Real world conditions for specific vehicle niche markets set the baseline for defining drive cycles, driving/usage profiles and customer demands. Also, environmental circumstances which influence emissions, heating, ventilation, air-conditioning and cooling (HVAC) are taken into account, as these aspects have a significant influence on the optimum REX design.
Project Context and Objectives:
2.1 Project Context
Worldwide, there is a strong trend towards highly efficient, low (preferably zero) emission vehicles, e.g. electrical vehicles. Factors that contribute to this trend are widespread concerns on: global warming and climate change (as effect of rising atmospheric CO2 concentrations), air quality (especially in urban areas: adverse health effect) and decreasing availability and dependency of fossil fuels.
Electric vehicles are able to cover almost 80% of average travel needs. However, many vehicle users require occasional longer distance travel capabilities of their vehicle. To relief this so-called “range anxiety”, there is a need for advanced plug-in hybrids and electric vehicles with range extenders for regular customer duty. For this purpose, highly efficient, compact, clean and low cost engines are required. Such systems are developed to provide battery charging over longer trips and/or in areas where electric recharge infrastructure is not (yet) available. For many application cases the target is to develop an electric vehicle for city driving with the ability to cover longer driving distances without any limitations compared to today’s vehicle comfort.
Most of the proposers of OPTIMORE are participating in the on-going FP7 project FUEREX . The main objective of the FUEREX project is to define and prove the best technology for range extenders from sub-compact passenger cars to light duty trucks in order to allow large market penetration of electric vehicles. Three types of spark ignition engines are being developed, capable of using renewable bio fuels as well as regular fossil fuels. This technology will enable a large reduction of CO2 emissions from passenger cars and light duty vehicles, since the market share of electric vehicles equipped with range extenders is expected to be much higher than for pure battery electric vehicles, due to both lower cost and higher driving range. Each of the developed range extenders are integrated and tested in a vehicle.
The major results of the FUEREX project are:
• Three range extenders demonstrating state of the art performance and integration
• Bench test demonstrating emissions, efficiency and performance for total RE
• Vehicle test demonstrating integration/NVH and vehicle performance.
OPTIMORE focuses on solving and overcoming well known shortcomings of BEVs and further develops and optimizes the range extender concepts from FUEREX results and experiences, simultaneously creating an important path towards customer acceptance of electrified vehicles and increasing the market penetration.
2.2 Concept and objectives
2.2.1 Concept of the OPTIMORE project
The OPTIMORE project takes on the challenge to develop and optimize the concept of the fully-integrated, range-extended, electrified light duty vehicle. Three different RE concepts will be developed and demonstrated to serve the niches from city vehicles, medium sized passenger cars up to light commercial vehicles.
The CONCEPT of OPTIMORE is based upon the following major elements.
The elements, their features and the major innovations are:
1. Definition of real world driving conditions (driving cycles and comfort requirements) as a baseline for further optimization and EV assessment
a. Real world conditions for specific vehicle niche markets set the baseline for defining drive cycles, driving/usage profiles and customer demands. Also, environmental circumstances which influence emissions, heating, ventilation, air-conditioning and cooling (HVAC) are taken into account, as these aspects have a significant influence on the optimum REX design.
2. Optimization of components and the whole RE system regarding emission, fuel consumption, cost, weight and exhaust gas after-treatment
a. Partly based on the results and the hardware of the FUEREX project the following further development will be performed: Optimization of REX for optimal battery capacity, REX power, emissions costs and control strategy cannot be divided into separate optimizations where the objectives are optimized one by one, as the different objectives are closely interconnected and partly in conflict with each other. A method is used that allows simultaneous optimization of the whole concept. What makes it even more challenging is that the optimization will be made not just for one typical driving cycle, but for a large set of driving cycles representing different types of users and different traffic environments.
3. Modular setup of an EV concept to fulfil a wide range of customer expectations
a. The experience with EVs up to now shows that this technology is too expensive. A modular setup / approach allows the same vehicle to be equipped with different drivelines based on customer demand. This enables OEMs to offer the optimum efficiency, functionality and cost for different customers. The same base vehicle, Volvo C30 electric will be analysed in three different versions: Pure electric drive only for short driving cycles, series range extender for city oriented use and parallel range extender for more highway use.
4. Advanced control strategies as a key for cost reduction and system optimization
a. Actual driving environment information like temperatures, speed, exterior and interior NVH levels;
b. Predictive driving and routing information, either taken from GPS based navigation type systems or from learned driving patterns.
c. This enables amongst others storage of energy in advance, providing backup for the REX in extreme situations and utilising REX for heating and cooling of the vehicle. But also, to enable fully electric driving where it is highly desirable (or even mandatory) such as in the centres of a growing number of cities.
d. Such control strategies have great potential for optimizing the performance over the trip in terms of comfort, fuel efficiency, emission as well as for achieving low overall system cost.
5. Functional and Electrical safety analysis and concept development to define necessary measures to fulfil and implement the ISO 26262 standard
a. The electrical system on board the EV-RE complies with the ISO 26262 functional safety standard for road vehicles. This primarily concerns the high voltage (HV) components on board and the precautions/measures to be taken in this respect.
6. Build-up and optimization of three technology demonstrator vehicles covering EV aspects for delivery trucks, all-purpose vehicles and city cars.
a. The build-up of demo vehicles is very expensive and time consuming. Within OPTIMORE it is only possible due to the fact that the consortium has already acquired knowledge and built-up first prototypes in FUEREX which will be utilized in OPTIMORE. This helps not only to keep the OPTIMORE budget, but it is an ideal situation to improve the technology in a very target oriented way. Three Fully Electric Vehicles (FEV) equipped with range extenders will demonstrate the largest potential to meet the customer demands in terms of efficiency, NVH, fuel type, exhaust emissions, dimensions, weight and costs. The three concepts are:
b. City compact electric vehicle, equipped with an innovative rotary engine for medium term (2020+);
c. A family (medium passenger) of new electric vehicles either as FEV or EV-RE equipped with a 3 cylinder piston engine (VCC/AVL-Schrick) used in a modular way, based on customer demands and their needs on the short term (2020+);
d. Light commercial electric vehicle, equipped with a 2 cylinder piston engine (CRF) optimized for weight and costs with an application on light commercial vehicles on the short term (2015+).
OPTIMORE takes on the challenge of simultaneously meeting the tough efficiency, emission, noise vibration and harshness (NVH), integration and cost requirements for a range extender. Each of the requirements can be met separately, but the main challenge lies in meeting them all and optimizing them at the same time - and - at a low enough cost to represent a competitive solution for the customer demands.
OPTIMORE targets for finding solutions – for both short and medium term – have large impact in terms of volume (market segments and number of vehicles) and ecological footprint (reduced (CO2) emissions, well to wheel efficiency, optimized weight and costs, etc.). The developed range extender concepts are expected to be very competitive, in comparison with battery electric vehicles but also in comparison with plug-in hybrid vehicles with a more traditional ICE power train, and therefore have the potential to be the main solution for passenger cars in the medium term perspective.
2.3 Objectives – Commercial Vehicle moving to efficiency in real driving cycles and approaching industrial sustainability
To approach industrial sustainability, RE components will be improved and optimized to reduce costs, weight and volume and to improve efficiency
To increase system overall efficiency during vehicle lifetime also an optimized hybrid capability will be implemented in an optimized range extender control SW.
1. Cost, weight and volume optimization of REX unit in light commercial Vehicle. Target weight reduction for REX is 20% together with a reduction of Range Extender length by 25%respect to FUEREX configuration.
2. RE fuel consumption and emission optimization acting both on ICE and electric machine efficiency and RE utilization strategies. Emission target is to match half of EuroVI standard with a correspondent best BSFC of 230gr/kWh.
3. Standardisation and modularization
Main results:
- Reduced Range Extender costs, weight and volume
- Improved Range Extender efficiency and emissions
- Improved control SW capability, including hybrid mode
2.4 Objectives – Modular Electric Range Extender vehicle
A modular approach towards an electric vehicle, which can be equipped with either an extra battery, a Range Extender for extra urban use or an ICE turbo charged with gearbox Range Extender for longer trips. With the help of this approach the electric vehicle can satisfy the needs of many potential customers.
Main results:
- An optimized parallel / serial Electric demonstrator Vehicle (Volvo C30/Volvo V60) in a modular way.
- Human Machine Interface for driver/user.
- Establish the correct controls for optimal use of the power sources in the vehicle (ICE, E-motor, E-motor/generator)
2.5 Objectives – Electric Vehicle – City car
Here, the approach is to develop an electric city vehicle equipped with a Rotary engine range extender. The operating system for the electric city vehicle will be adapted to real world operating conditions with special attention to user comfort needs and emission requirements. Reliability, performance and cost of needed hardware will be optimized and identified to reflect production intent material, cost and safety level.
Main results:
- Optimized hardware and advanced operating strategy for real world driving conditions
- Verification of ISO 26262 compliance for operating system.
- Identification of cost reduction potentials for volume production.
2.6 Objectives – Functional Safety Development
A functional safety concept will be worked out to assure safety in electric and hybrid vehicles containing a high voltage battery. Herein potential hazards due to torque handling of the appropriate control units as well as the high voltage contact safety will be considered. Potential risks will be minimized by both hardware and software measures.
Main results:
- HV contact safety
- HV battery technology safety (in terms of overloading, overheating, etc.)
- Control algorithm monitoring features
2.7 Objectives – Optimization of range extender, battery size and control for different vehicle niches
The optimization method and the analysis of optimal sizing for different vehicles are aimed to support the commercialization of the REX technologies, rather than to optimize the demonstrator vehicles within OPTIMORE. The demonstrator vehicle will show that the technologies meet the expectations, while the ability to define attractive and cost effective REX systems for a wide set of vehicles will be demonstrated through a theoretical simulation study.
Main results:
- Defined driving cycles to be used for the optimization of the range extender sizes, describing typical use for the investigated vehicle types, the variations between different type of drivers and environments needed to create robust range extender concepts.
- Knowhow and computer algorithms to optimize the size of the range extender and the battery size as well as the control strategy using the driving cycles developed. Especially this includes algorithms to optimally decide the sizing of a number of vehicles for a vehicle market represented by the drive cycles of the drivers. This gives the optimal division of the set of drivers into subsets, distinct vehicle niches, and the sizing of each niche.
- Knowhow of the relationship between driving cycles and REX performance in order to design optimal REX solutions for defined niches.
2.8 Objectives – Dissemination and exploitation
Main objective of this work package is to establish an appropriate and effective communication of the project results towards relevant stakeholders and the automotive community in general.
Main results:
- Dissemination plan
- Project website for dissemination to the broad public
- Workshop for relevant stakeholders
Project Results:
This chapter describes the main achievements of the project per main objective.
3.1 Commercial Vehicle moving to efficiency in real driving cycles and approaching industrial sustainability (Fuel consumption, efficiency and emission optimization)
Main results for the Optimore Electric Daily Range Extender version come from the experience of the Iveco Daily Electric major customers: according to the data of the usage of their vehicle, in general, Electric LCV daily mission for urban delivery is around 80 km per day. Sometime having suburban operation as well increased mileage can be necessary and for this reason a hypothetic daily cycle was identified:
52 Km for SUBURBAN CYCLE (≈60%)
33 Km for URBAN /DOOR TO DOOR CYCLE (≈40%)
Respectively divided in:
14 km at the average speed of 11Km/h - (URBAN)
18 Km at the average speed of 6,7Km/h - (DOOR TO DOOR)
52 Km at the average speed of 50 Km/h - (SUBURBAN)
With an average speed of 14km/h.
Have been considered 230 working days and a consequential mileage around 20.000 km/year; with this kind of cycle the possible situation that occurs each time SOC decreases below 40% and the range anxiety rises for the driver has been covered.
In order to increase vehicle flexibility and avoid the above mentioned drivers anxiety, but also maintaining urban delivery targets and electric operation during vehicle lifetime as well as reducing batteries weight and cost, range extender version specifications were fixed as following:
Considering the average speed of 14km/h, and considering that the energy consumption of this kind of vehicle is theoretical around 350 Wh/km, we estimate an average power of 4.9 kW.
After the tests performed on road, emulating the condition of the Hypothetic urban cycle, the results were an energy consumption, in electric mode, of around 360 Wh/km with an average power of 6.8 kW. The consequential electric range was 48 km.
This is a good value if we consider that , respect to the FUEREX demonstrator, on OPTIMORE demonstrator there is less embedded energy (only one battery pack); in fact , thanks to the new configuration with the Supercaps modules in parallel, the battery , working in a “comfort zone” , can guaranty to the complete system better performances and better efficiency than FUEREX.
During the test done in Hybrid/R.E. mode, although the hybrid capability implemented in the optimized range extender control SW on the AVMU control unit works properly, the RE fuel consumption and emission optimization were not completely in line with the targets: the optimization of the system calibration was not possible due to the sudden failure of APU inverter.
Anyway, despite the not optimized values of fuel consumption, with the fuel tank integrated on the vehicle (25 liters), it was possible to guarantee a R.E. range of around 207 km that is a value that can cover the ranges of the Hypothetic cycle:
52 Km for SUBURBAN CYCLE (≈60%)
33 Km for URBAN /DOOR TO DOOR CYCLE (≈40%)
On the other hand, as said before, the Pure Electric range, thanks to the new optimized ESS system, is completely achieved.
Cost, weight and volume optimization
To approach industrial sustainability, RE components have been improved and optimized in order to reduce costs, weight and volume.
The target weight reduction for REX was 20% together with a reduction of Range Extender length by 25% respect to FUEREX configuration.
The Optimore engine configuration starts from the Fuerex one, moving towards reducing cost and weight (industrial sustainability) and improving efficiency in real driving cycles: from this point of view the Optimore engine is a twin cylinder gasoline one, natural aspirated version. In fact a gasoline engine, if we include the fuel storage system, is much easier and lighter respect to the NG one and the availability of the fuel (gasoline) guarantees an easy capillary distribution of the vehicles.
Last but not least, the simplification of the engine implies an obvious cost reduction.
In the following table a comparison of the two different engine system configurations, in terms of weight, is shown:
The weight reduction in the Optimore configuration is around 50%, much higher than the target that was 20%.
The most important contribution to the weight reduction is given by the replacement of the CNG storage system with a standard gasoline tank. Another improvement is the weight reduction of the electric machine, thanks to the implementation of a different EM technology that allowed the design of a lighter machine. Concerning the length, thanks to the integration study of ICE and electric machine at mechanical level, the total length of the system is around 500 mm, taking to a length reduction of more than 30% respect to the FUEREX configuration
In conclusion, in terms of efficiency, the new E-machine compared to the Bosch E-Machine, seems to be less performing, but this is basically due to the absence of the permanent magnets in the rotor stack. In fact the Bosch E-Machine is a synchronous reluctance machine with internal permanent magnets (much more efficient especially at low rpm, up to the base speed), moreover the torque production capability is higher because of the even bigger active parts volume.
In fact the Bosch E-machine can provide up to 80 kW in overload condition, the new E-machine instead can provide up to 50 kW in overload condition.
At the same time the new E-machine is lighter, smaller and quite cheaper if compared to the Bosch E-Machine.
In order to reduce the technological gap between the two E-machines (our E-Machine has no permanent magnets) an innovative stator winding was designed and a customized rotor lamination was developed in order to make possible a direct drive installation with the ICE’s shaft. This solution made it possible to remove the mechanical interface between ICE and the Bosch E-Machine, with a large reduction of weight and size of the hybrid powertrain.
In the following table is summarized the comparison between the two E-machines:
In the first three columns is possible to find the comparison in terms of actual efficiency referred to a winding temperature of 100 °C . The gap is more evident at the lower speed, but this is just a peculiarity due to the two different types of E-Machine, in fact the permanents magnets give a substantial advantage in terms of torque production from the zero speed up to the base speed.
This gap is also due to the lower active parts volume (-32%); in fact the torque production capability is directly dependent on length and diameter of the active parts (at constant max phase current).
Standardization and modularization
For the standardization point of view we can state that:
- For the cooling system , respect to the FUEREX demonstrator, two normal production radiators have been used
- The HMI application implemented uses two standard Off-the-Shelf components and only the SW application has been customized.
- The battery package is a standard pack already used on Daily electric.
For the modularization point of view we can state that :
- The SW components implemented on the AVMU and on VMU allow to manage different configuration of the system and we would be able to change the number of battery of supercaps in order to fit the needs of different customer profiles.
- Also the modularity of the HW components used would allow us to change the vehicle configuration according different needs in terms of energy or power.
Demonstrator
The result of the final integration of the various components is:
3.2 Modular Electric Range Extender vehicle demonstrators
The VCC modular approach contains three different drivetrains which can be integrated into one electrified powertrain platform. It contains of a tunnel battery and an optional rear drivetrain providing different attributes and resulting cost.
Volvo C30 Electric have been chosen as a baseline, and the Optimore concept is a Parallel/Series hybrid. In addition to a pure series hybrid, the consumption during highway driving improves with drivability and performance.
Teh concept with the rear subframe contains the dual clutch transmission with the electric machine integrated in the gearbox. The subframe contains driveshafts within the same assembly and the engine mounts are similar as in Fuerex. The difference in this concept is that the movement of the rear powertrain will be larger, as because of pre-tensioning the drivetrain when transferring wheel torque. The Electric machine in the Optimore transmission is assembled on the even shaft axis.
The main results in consumption performance can be seen in Table 1 below. The concept itself fulfills the requirements for Euro 6 emission levels, although the prototype used in the project cannot fulfill these levels due to early prototyping material. In order to run the engine in efficient operating points, knock compensation need to be well calibrated to run efficiently. The higher sustain consumption in the Optimore concept can partially be explained by a spark retard at part-loads and the higher road load for the Optimore prototype than for Fuerex. This will also affect the emission results, why Table 1, Annex I, Part B could not be fulfilled fully within this project.
Table 1 Representing the Consumption performance of each concept where red values are representing simulated values and green are representing values measured within the scope of the Optimore project
C30 BEV C30 Fuerex Optimore
Results and Attributes Data Concept 1 Concept 2 Concept 3
Fuel Economy Fuelconsumption
@ 90 kph [l/100 km] 0 5,5 4,1
CO2 @ 90 kph [g/km] 0 128 97
CO2 NEDC depletion [g/km] 0 0 0
CO2 NEDC sustain [g/km] 0 166 183
Electric Range [km] 161 60 60
NEDC CO2 rating [g/km] 0 26 28
HMI Demonstrator and Work
The goal to find a non distrurbing ECO-Coach function started with case study what problems which occur related to limited electric range. This continued with analyzing the disturbance effects which can lead to limited electric range which are caused the driver. These disturbance factors which are related to the usage and driving of the car, have been the key focus information to distribute in a non-disturbing way. Also, a benchmark of the current market HMI have been carried out on already implemented competitor interfaces, to understand how they relate and affect the driving. One example is trees with growing leafs when driving efficiently and different type reward systems in the design. The focus in this project have been rewarding the driver driving efficiently by not displaying any information in order not to cause any distraction, different from the market today. The main driver related disturbance factors for electric range have been identified as:
- Driving too fast, road resistance increase with Air Drag
- Accelerating too hard, so the optimal efficiency of the drivetrain cannot be achieved
- Braking too hard, with saturated electric recuperation and engaging friction brakes
Also, a guidance range meter was implemented to feedback how the electric range is affected by the road load polynomial. In this way, one would know which Eco-speed to aim for to avoid engine starts when driving towards a destination.
3.3 City Electric Vehicle demonstrator
The targets of this WP were; To optimise the system layout, To improve the hardware and to industrialise the software, To reduce the cost and To optimise the whole system based on the detailed development.
The system layout of the city car was optimized based on real world conditions and the experience of the previous project FUEREX regarding drivability, fuel consumption, emissions, cost and NVH:
- by associated REX operating strategy, driven by State of Charge requirements
- Thermal management under real-world conditions for the optional use of electric energy and/or waste heat generated in the RE unit
- Comfort demand combined with the technical thermal management of the power train and the impact on efficiency, durability and emission
The hardware and SW were further developed by
- Eliminating of expensive (prototype) materials and processes,
- Improved aftertreatment functionalities,
- Evaluation of different design solutions to improve packaging and NVH,
- Developing next level of power electronics regarding automotive requirements, volume and weight reduction.
The SW industrialization was concentrated on functional safety, comfort features and integration into operating software which finally represents a solid base for further specific applications:
- Development and testing of fail-safe procedures for the charging process
- Integration of optional communication to the charging infrastructure
- Safe start procedure for control units and proper initialization sequences
- Integration of air conditioning and heating strategies
- Optimized creeping mode for low speeds in city operation
- Redundant control algorithms on vehicle and engine control unit for error detection and recognition of shutdown or limp home conditions
- Variable recuperation modes on driver demand
- Development of range extender multi-point operation for flexible adaptation
- Implementation of emission relevant functions like charcoal-canister purge
The development was based on the Control Units and the E-Vehicle architecture.
The cost reduction of the Range Extender under reliability aspects addressed:
- Evaluation of well-known volume production materials and technologies for the use in the rotary engine production.
- Beside cost reduction on component level, various sub-systems were simplified or combined to reduce complexity and weight.
- The cooling/heating system of the ICE, aftertreatment system, E-motor and battery regarding hardware, operating and control strategies were optimized.
The production cost assessment was performed for the range extender unit incl. exhaust system for two different production scenarios:
Scenario 1: Volume: 20.000 units/year, OEM production, brownfield approach
Scenario 2: Volume: 100.000 units/year, Tier 1 Supplier for different OEM’s, brownfield approach
The system optimization was performed under two main aspects, the legal NEDC test cycle and representative load profiles for EVs. The operating point of the range extender has a high influence on NVH behavior in the vehicle especially under low speed conditions at city driving. This aspect was optimized once again with the final performance of the range extender in the vehicle. Based on these criteria the durability aspects are of minor priority at real live conditions.
The final results of the rotary range extender are shown in Table 2. Compared to the project targets the NVH behavior, the weight, and space targets were fulfilled, while the cost targets can be kept at a production volume higher than 100.000 units per year. The specific fuel consumption is app. 5 % higher than the target value, the emission level at NEDC is at 65% of EU6 (target was 50 %). The reasons for that are the HC emissions.
The final integration of the Wankel Range Extender into the city car with the targets; excellent driveability, excellent NHV behaviour and no constraints of the passenger compartment and car boot were achieved.
The vehicle concept provides an electric range for average daily need of approx. 50km with a high voltage battery of 12 kWh. The battery management is designed for an energy and power reserve required for full dynamic vehicle performance. The vehicle is equipped with an electric motor of 75kW & 240Nm peak torque, the energy consumption will be 16kWh/100km, and the fuel tank size is dimensioned for 250km total range. The fuel consumption of 1.8l/100km is measured under real driving conditions at daily use in a timeframe of March 2014 to October 2014.
Important for the electric driving range are the load profile, heating in wintertime and air conditioning in summer time. The lower the average speed the more negative impact of heating and air conditioning appears. Whereas the electric operating range is decreasing by 40 % in the NEDC cycle due to air conditioning, in the New York City Cycle the electric operating range is shrinking by app. 60 %.
3.4 Functional Safety Development
Motivation and Achievements:
In the course of the OPTIMORE project co-funded by the European Commission, AVL-SCHRICK developed a complete generic functional safety concept applicable for range extender electric vehicles (RE-EVs). It was created to be used as a baseline for all functional safety and system level FMEA work packages in RE-EV production programs for the OPTIMORE project partners and AVL-SCHRICK itself.
The generic functional safety concept is developed based on the methodical and structural principles described in the ISO 26262. According to the definition in this standard, the following set of documents was created:
- Generic Item Definition for RE-EVs
- Generic Hazard and Risk Analysis for RE-EVs
- Generic powertrain system FMEA for RE-EVs
- Generic Functional Safety Concept for RE-EVs
Generic Item Definition
For the creation of a generic item definition for range extender electric vehicles (RE-EVs), the following steps were executed by AVL-SCHRICK:
Definition of a generic RE-EV powertrain architecture applicable for the target vehicles of the OPTIMORE partners and also for other RE-EV applications.
Definition of the main functionalities of the generic RE-EV powertrain and allocation to a responsible hybrid powertrain component / control unit.
Definition of the system boundaries for the functional safety development. The system boundaries indicate which components are taken into account completely for functional safety development and which interfaces to environmental components have to be considered. The boundaries are illustrated in a generic system boundary diagram showing all identified powertrain components and the respective internal and external component interfaces.
Definition of the high voltage circuitry. As the HV storage system and the corresponding consumers and circuitry are highly critical in terms of safety development, a generic HV architecture including all HV components, switches and wiring for RE-EVs was defined and agreed.
Detailed definition of RE-EV functionalities including boundary conditions, function sequence and functional allocation to target controller. For each function the trigger conditions, a description of the function sequence and the exit conditions were identified. Each sub-task during a function was allocated to a designated target controller which is responsible to control and monitor the respective task.
Identification of RE-EV operation scenarios as input for Hazard and Risk Analysis (HRA). The final part of the Item definition contains a collection of operation scenarios for the RE-EV including the type of streets, the traffic situation, the driving situation and the environmental conditions.
Generic Hazard And Risk Analysis
On the basis of the item definition, a generic Hazard and Risk Analysis (HRA) was created and agreed with the OPTIMORE partners applicable for all RE-EV concepts. In the HRA, a rating of possible malfunctions of the defined functions was done under consideration of the driving situation and environment as defined in the item definition. The generation of a HRA is divided in two different phases:
- Preparation phase with collection and structuring of required inputs from item definition, generic databases and other sources.
- HRA session phase with common workshops to identify hazards, discuss their ratings and to derive respective safety goals.
Altogether, 73 hazards were identified, described and evaluated for generic RE-EVs. The rating for Severity, the Exposure and the Controllability for each failure mode was executed according to ISO 26262 methodology. Composed out of these three ratings, an overall safety level was calculated (Automotive Safety Integrity Level – ASIL):
40 hazards rated with QM
17 hazards rated with ASIL A
11 hazards rated with ASIL B
2 hazards rated with ASIL C
3 hazards rated with ASIL D
For all hazards with ASIL higher that QM, a safe state was determined and described in the safety goal as input for the functional safety concept.
Generic Powertrain System FMEA
A generic powertrain system FMEA was created based on a generic RE-EV architecture and related functionalities as agreed with the OPTIMORE partners in the RE-EV Item Definition. The FMEA identifies countermeasures on (sub-) system and component level to prevent powertrain failure modes with high severity. The approach for creation of the FMEA was the following:
- The systems and components of the RE-EV powertrain are identified and assigned to the levels powertrain level, (sub-) system level and component level. Each component is linked to the related system and the powertrain.
- The main functions for the powertrain systems are identified.
- For each system and each related function, potential failure modes are identified which compromise the functionality of the system or the passenger safety.
- For each system failure mode, potential effects on powertrain level are identified and rated concerning their severity. The rated severity is cross-checked with the results of the HRA to ensure the quality of the functional safety work.
- For each system failure mode, potential causes on component level are identified.
- For each failure mode on component level causing effects with high severity (≥ 7) at powertrain level, preventive actions and detection actions are defined.
As a result, a large list of preventive and detection actions for each component of the RE-EV powertrain was created describing measures to increase the robustness of the system and to prevent critical failures with potential impact on RE-EV driver and environment safety. The list includes more than 500 actions assigned to the different components.
Additionally to the already specified countermeasures, the output of this powertrain system FMEA can be used as in input for the component FMEAs to be done component suppliers in vehicle series development programs.
Generic Functional Safety Concept
Based on the previous functional safety tasks (creation of item definition, preparation of hazard and risk analysis) a generic function safety concept (FSC) was created applicable for generic RE-EV architectures and related functionalities as agreed with the OPTIMORE partners. In the FSC all identified safety goals of the HRA were derived in functional safety requirements and allocated to the elements of the relevant safety architecture concept.
The applied approach to develop the Functional Safety Concept for generic RE-EV architectures in the OPTIMORE project is composed in the following steps:
- The safety goals with the assigned ASIL levels and the safe states identified in the hazard and risk analysis are the basis for the derivation of functional requirements in the FSC. The safety goals coming from the HRA are combined to ten safety goals in the FSC. The highest ASIL rating of the HRA safety goals is applied to the safety goal in the FSC.
- If applicable, a decomposition of the ASIL rating according to the regulations as defined in ISO 26262 is done (applied on one safety goal).
- For each safety goal, at least one functional safety requirement is defined.
- Each functional safety requirement is allocated to the related architectural elements of the item.
- For each functional safety requirement, a safe state is defined.
- For each functional safety requirement, a fault tolerance time is defined.
- For each safety goal, a safe state is defined (considering the safe state of the functional safety requirements).
- For each safety goal, a fault tolerance time is defined (considering the fault tolerance time of the functional safety requirements).
- If applicable, additional requirements safety instructions are defined (warning concept, etc.).
For the ten identified safety goals, in total 71 safety requirements were defined to be applied to the different components of a generic RE-EV powertrain.
As a results of the functional safety concept, the final step of the functional safety investigation for RE-EV concepts, a large number of generic requirements has been defined, discussed and handed over to the OPTIMORE project partners. The defined requirements shall be used by the partners as a baseline for their own functional safety process in order to shorten the time-to-market of their respective vehicle. At the same time, the results are also used by AVL-SCHRICK to strengthen their market position as engineering partner for RE-EV solutions by reducing the effort and time and thus cost during respective development programs.
3.5 Optimization of range extender, battery size and control for different vehicle niches
In this section the main results concerning the objectives in Section 1 are described.
Optimal battery size
To illustrate the methodology developed, a real world movement database with more than 400 drivers is used.
The data describing the drivers can be described by a density function f(x) which equals the fraction of trips by this driver of length x. The total number of trips is indicated by T. The vehicle is assumed to be re-charged after each trip. The main variables to be considered in the sizing are the battery size, described as All Electric Range (AER) with price C_batt per kWh, the distance the vehicle can drive electrically, and the range extender size. The energy costs, fuel and electricity are indicated by f_km and e_km, respectively. Using this notation, the Total Cost of Ownership (TCO) as a function of AER is expressed by the relation.
(for the equations, please refer to the pdf file including)
This is the fundamental relation used for all investigations concerning the sizing of components, the dependency on the drive cycles, the sensitivity of the sizing etc.
When computing the optimal battery size for the 400 drivers contained in the database and grouping them in vehicle niches is easier to visualize which drivers are group together. For the case one wants to offer three battery sizes and a conventional vehicle to this group of drivers.
This also illustrates the sensitivity of the optimal choice by changed conditions by how much the intersection change. Other measures of sensitivity, for example, how much TCO change for the individual drivers due to changes, eg, if the fuel price change, has been investigated based on the relation of TCO. All these results can nicely be illustrated in figures.
Smaller Range Extender Size
The normal energy management strategy for RE-vehicles is to use the cheap electric energy first and start the RE when the battery is empty which happens if the trip is longer than the AER. This is called Charge depletion charge sustaining (CDCS) strategy. If the driving distance is known in advance, a not unrealistic assumption, Blended Charge Depletion (BCD) is an alternative where the battery and the RE are used in parallel during the whole trip and this makes it possible to downsize the RE without reducing the performance of the vehicle. This is shown here in an example where the required RE power to complete motorway driving cycles of different distances are compared.
Motorway driving is represented by an Artemis motorway driving cycle. The battery size in this example is of 14kWh battery, which allows for approximately 47 km AER in an Artemis Motorway driving cycle. The RE sizes needed as well as the depending on maximum trip distance.
Several conclusions can be derived:
- The RE size for CSCD mode is independent on the distance of the driving cycle. It only depends on the average power demanded in the CS part of the driving.
- The reduction in RE size when driving in BCD mode is proportional to the ratio between the driving cycle distance and the AER of the vehicle.
Another criterion for sizing of the range extender is performance during climbing, Table 4 shows the extra energy needed from the battery in order to climb 1000 meters with a 25 kW RE but maintaining the performance level of a 35 kW RE. Hence, as long as this energy is available in the battery before the slope, the 25 kW RE has the same performance as the 35kW RE.
1000 meters climb at: CSCD Mode BCD Mode
120 km/h-2% slope 35 kW 25 kW + 2.74 kWh
100 km/h-5% slope 35 kW 25 kW + 2 kWh
70 km/h-10% slope 35 kW 25 kW + 1.58 kWh
Table 4. Extra energy from the battery to climb 1000 meters when downsizing the RE power from 35 kW to 25 kW.
If the vehicle is able to anticipate and save that extra energy in the battery a 25 kW RE could offer similar performance than a more expensive, heavier 35 kW RE.
Charging the battery with RE power will be possible in many driving situations. Driving the vehicle in an Artemis motorway driving cycle a 25 kW RE is able to recharge 2kWh into the battery in around 18 minutes, and if the vehicle is driving a less power demanding rural environment (Artemis Rural) the same 2 kWh can be charged into the battery in just 10 minutes.
A 35 kW RE would cost around 2800€ while the cost of a 15 kW RE would be in 1500€ level. Assuming a linear dependency between power and cost a 25 kW RE would cost approximately 2150 €, which represent 650 € savings from a 35 kW RE.
Potential Impact:
4.1 Expected impacts listed in the work programme
The OPTIMORE project contributes to the expected impact listed in 7.2.7.THE ‘EUROPEAN GREEN CARS INITIATIVE’ under the topic Research on electric and hybrid vehicles
GC.SST.2012.1-5 Integration and optimisation of range extenders on Electric Vehicles
Although Electric Vehicles are able to cover almost 80% of average travel needs, the residual need of many vehicle users for occasional longer distance travel means that range-extended electrified vehicles provide an important path towards increasing the market penetration and customer acceptance of electrified vehicles, by relieving the so-called “range anxiety”..
The focus of the research will be on developing and optimising the concept of the fully-integrated, range-extended, electrified light duty vehicle which will offer both significantly reduced impact on the environment and long range capability. The aim is to optimise the integration and control of the electrified vehicles equipped with a range-extender while ensuring that the range in pure-electric mode, typically charged using the grid, is sufficient to cover average daily mileage.
The activities should address the following issues:
• Optimisation of the ICE used as the range extender and of its after treatment system.
• Impact on optimal battery capacity.
• Advanced control strategies.
• Modularisation.
• Performance, safety, recyclability and cost.
• Characterisation, standardisation and synergies with other applications.
• Existing engines from other applications potentially well adapted to the range extender role
4.1.1 Why introducing Fully Electric Vehicles (FEV)?
To achieve a sustainable transport sector the net CO2 emissions from fossil fuels must gradually be eliminated. Already by 2020 a significant reduction must be reached, but that is not enough and the net CO2 emission must continue to be reduced completely during this century. To achieve this non-fossil energy sources must be used. The main sources available are fuels from biomass, hydrogen from renewable sources or electricity from wind-, hydro-, solar- or nuclear power.
Bio fuels are a technically feasible option, but there is a competition for the biomass resources from many sectors in society, like food, energy and feedstock for the industry. The potential for sustainable biomass production is far too small to meet all the demand for it. Therefore the biomass will be used by the sector, which is prepared to pay most for it and recent studies indicate that this will mainly be the food sector, parts of the stationary energy sector and a feedstock for industry. Vehicles will most likely be rather run on electricity, for cost reasons. It is also likely that bio fuels will be used in some special parts of the transport sector that cannot be electrified, like air and sea transport, special vehicles and some part of the long haul transports. Renewable electricity will most likely also be a scarce resource for many years to come, but in comparison with biomass it is likely to be both cheaper and more easily produced in large quantities.
Hydrogen is also a competitor to battery electric vehicles, and then mainly as fuel cell hydrogen vehicles. It is a technology which is more difficult to draw certain conclusions about. Hydrogen will in many respects be comparable to electric vehicles in that they will also be quiet, no toxic emissions and no CO2 emission from the vehicles. However, the main drawback of hydrogen lies in the need for a completely new infrastructure for hydrogen supply. When it comes to cost for the energy the picture is not fully clear, but it seems likely that electric energy can be produced at a lower cost, at least in the short to medium term perspective.
Electric cars are quieter, cleaner and cheaper to run than cars equipped with an Internal Combustion Engine. Below, in a nutshell, are a few key benefits of electric cars:
1. Electricity is cheaper than gas, a difference which is likely to increase as oil becomes a scarce resource, and can come from renewable resources such as solar and wind power.
2. Electric cars pollute less than gas-powered cars (especially when renewable energy sources are used to generate the electricity).
3. By using domestically-generated electricity rather than relying on foreign oil, we can achieve energy independence.
4. Electric cars can utilize the existing electric grid rather than require the development of a new, expensive energy infrastructure (as would be the case with hydrogen).
4.1.2 Why Electric Vehicles with a Range Extender and projected impact of OPTIMORE
As mentioned before, there are many benefits for an electric vehicle. So why have they not yet been fully adopted?
The introduction of electric vehicles is delayed by several problems of the chicken or the egg type:
• Electric vehicle are too expensive and therefore almost non existing, due to the battery price – Batteries are too expensive due to the low volume of production.
• Electric vehicles require a charging infrastructure with high coverage in order to be attractive – Building a charging infrastructure is only attractive once there are many electric vehicles that pay to use it.
• The limited range of the electric vehicle is a problem since the batteries are expensive and heavy. – Once electric vehicles are the standard solution the short range is less of an issue since charging infrastructure will be available almost everywhere.
Range extender vehicles will be the important evolution step which enables the unlocking of the above mentioned lock-in mechanisms. This is enabled since the range extender vehicles allow:
- Reducing the battery costs for the consumer: since the range extender makes it possible to size the battery only for the typical driving distance rather than for the occasional long distance trip. As a result, the batteries cost for driving this vehicle will be much lower than an EV without a REX.
- Charging of the batteries: due to the fact the REX is available charging the batteries is not a crucial issue anymore and the advance planning for the use of the car will be much less crucial. Still the drivers will normally use the available charging stations and thus creates market demand that encourages a continuing expansion of the charging infrastructure.
- Limits on driving distance: Most of the electric cars have limits on how many miles they can go before needing a recharge. The REX solves this issue by allowing a small and cheap battery which is often used to its limit in order to maximize electric driving range. The range extender provides the confidence to do this, while it will still only be used for a rather small part of the total driving range of the vehicle. As the range extender vehicles will have created a “critical mass” for battery volumes and charger infrastructure, the fully electric vehicle will gradually be able to replace many of the REX vehicles as the batteries become cheaper and have higher energy density, and with growing possibilities to charge almost anywhere.
Also, one of the biggest problems for pure-electric vehicles is not just the driver’s ‘range anxiety’ but also the huge draw on battery power required by lights and heating in winter. Cold weather also wallops the battery’s performance. It is not foreseen that these issues are being solved on the short term. The EV has a promising future but it will be at least a decade away for electric vehicles breaking through into the mass consumer market. However, the ultimate goal will be to have a fully electric vehicle.
The Electric Vehicle with REX provides the opportunity to tackle the above mentioned issues. And also important, it provides the opportunity to anticipate the foreseen developments relative to a 2011 battery:
• Improvements of 20 to 25% in specific energy with a similar reduction in cost by 2016 primarily due to improved battery design and packaging;
• Improvements of 70 to 75% in specific energy and 50% reduction in cost per kWh by 2020 to 2022 with the introduction of advanced materials for the anodes and cathodes, such as silicon anodes;
• Potential for a tripling of specific energy and 70% cost reduction per kWh by 2030 with the introduction of lithium-sulfur batteries;
The current costs of lithium batteries are based on battery manufacturer quotations to car manufacturers at rates of about 20 thousand per year for supply starting in 2011/2012. Future costs to 2020 and 2030 are based on using current cost numbers and accounting for effects of volume, scale and in the case of the battery, new technology, as shown below.
The key about combining a petrol engine/generator and battery pack is that it can deliver the performance of a big internal combustion engine along with very low emissions of both CO2 and pollutants.
Battery cost and size mean that all-electric cars still have a relatively limited operating range. With the range extender, the electric car has its effective range increased by a thousand kilometres - yet with the average carbon dioxide emissions below or way below 50 g/km.
OPTIMORE’s contribution to solving the problem
As explained, the electric passenger cars that are currently being developed are not yet competitive with conventional vehicle technology and do not meet the customer needs to a large extent. Three Fully Electric Vehicles (FEV) equipped with range extenders will demonstrate the largest potential to meet the customer demands in terms of efficiency, NVH, fuel type, exhaust emissions, dimensions, weight and costs. The three concepts are:
a) City compact Electric Vehicle, equipped with an innovative rotary engine for medium term (2020+)
b) A family (medium passenger) of new Electric Vehicle either as FEV or EV-RE equipped with a 3 cylinder piston engine (VCC/AVL-Schrick) used in a modular way, based on customer demands and their needs on the short term (2020+)
c) Light commercial Electric vehicle, equipped with a 2 cylinder piston engine (CRF) optimised for weight and costs with an application on light Commercial vehicles on the short term (2015+)
OPTIMORE delivers solutions for both short and medium term that have large impact in terms of volume (market segments and number of vehicles) and ecological footprint (reduced (CO2) emissions, well to wheel efficiency, optimised weight and costs, etc.). The developed range extender concepts are expected to be very competitive both in comparison with battery electric vehicles but also in comparison with plug-in hybrid vehicles with a more traditional ICE power train, and thus they have the potential to be the main solution for passenger cars in the medium term perspective.
Economic impact of OPTIMORE
Optimore will reduce the dependence on oil and to reduce emissions. With the global requirement to reduce CO2 emissions driving a move to the increased electrification of the vehicle, the realities of economics provide a serious challenge for electrical cars.
Although OPTIMORE has its focus on the application in battery electric vehicles with range extenders rather than on plug in hybrids, there are many similarities between range extenders for battery vehicles and plug in hybrids.
It is therefore safe to say that OPTIMORE has an impact in accelerating the sales in both EV and PHEV markets with a focus on sub-compact passenger cars and light duty commercial vehicles. The reason for focussing also on this particular segment is the expected dramatic increase of freight transport inside high concentration urban areas during the next decade. For its specific mission profile this kind of vehicle can, of course, get the maximum benefit from the electric driving mode (noise, vibration, pollution, frequent stop&start situations) while the Range Extender approach will supply a higher flexibility in terms of fleet management.
Market introduction of RE-BEV’s will be accelerated directly by the OPTIMORE auto manufacturers Volvo Cars and the FIAT group (represented by IVECO) but also through the RE engine manufacturers in the AVL group that will supply other car manufacturers with integrated RE solutions. Obviously, both exploitation routes will have beneficial effects on Europe’s automotive industry in terms of competitiveness and employment.
Environmental impact of OPTIMORE
In Europe, the European Union is committed under the Kyoto Protocol to reduce GHG emissions by 8 per cent by 2008-2012 compared to the 1990 level. In addition, the EU has committed to a 20% cut in its greenhouse gas emissions by 2020. The EU has also adopted a target improving energy efficiency in the European Union by 20% by 2020.
The OPTIMORE concepts meet these targets and even more important the project will address all main obstacles for developing successful electric vehicles and thus play a major role in the greening of the transport sector in Europe. Not only are electric vehicles more efficient in their use of energy, they produce no direct greenhouse gas emissions. There is also an indirect effect of introducing low CO2 emission vehicles, since they make buyers aware of the possibility to lower the fuel consumption even further. The introduction of hybrid vehicles triggered a significant improvement of the fuel consumption of traditional ICE power trains, and it is likely that the introduction of Range Extender vehicles with an attractive performance will increase the customer demand also for other sorts of low fuel consumption vehicles.
In the environmental comparison of conventional BEV’s and RE-BEV’s, another important issue related to the battery mass is worth mentioning. The specific power density of a battery system is in the range of 0.1kW/kg thus a nominal range (extension) of 100km requires an additional battery weight of 150 – 200 kg, which is equivalent to a surplus in fuel demand 0.4 to 0.8L /100km in customer duty. The range extension by a range extender engine has a much lower weight penalty for common customer range requirements leading to only a minor fuel consumption penalty relative to an urban area BEV with a range of 50km only.
4.1.3 Added value of a European approach
The aims of OPTIMORE can be best achieved by addressing the research at European level rather than at national or private level. The main reasons are the following:
• Car manufactures and (first tier) suppliers are operating/acting on a European (even world wide) scale rather than a national scale;
• Greening of road transport and in particular Electrification of the vehicle fleet is a European and even global issue;
• Reducing the emissions in road transport is a major societal concern common to all European countries and it requires a sustained effort at European (and global) level to achieve significant improvements;
Moreover, the initiation of OPTIMORE at European level enables to bring together partners with excellence in necessary fields of expertise, which are not adequately available at national level. The OPTIMORE consortium fits together perfectly to find system solutions as the basis for future customer programmes and products meeting these targets. It brings together engine specialists (AVL, CRF), major auto manufacturers (Volvo Cars and the FIAT group represented by CRF and Altra), and scientific excellence in the fields of combustion engine technology, hybrid vehicle technology (Chalmers) and alternative fuels (AVL and Chalmers).
4.1.4 Contributions to standards and regulations
There is a need to standardize driving cycles for vehicles with range extenders, to enable efficient ways of calculating relevant figures for emissions and fuel/energy consumption. The work within OPTIMORE will contribute by describing important aspects of the driving cycles. However, it is not a primary goal of OPTIMORE to define standard drive cycles as it is expected that standards will not be defined until there is significantly more experience with range extender vehicles on the European roads.
4.1.5 Collaboration with other (inter)national research activities
Collaboration is foreseen with Coordination Action ULYSSES (The future propulsion as one system) and the large-scale collaborative project HI-CEPS (Highly integrated combustion electric powertrain system), belonging to the CA ULYSSES, both led by CRF. The research done in FP7 project FUEREX will be used as a basis for OPTIMORE.
The Chalmers research on system analysis/control and combustion engines is carried out in close cooperation with research on related topics within several national Swedish programs.
4.1.6 External factors that may determine whether the impacts will be achieved
Electric-drive vehicles are unlikely to succeed in the next five to ten years without strong policy support (governmental/tax incentives) in the area of making vehicles cost competitive with today’s internal combustion engine (ICE) vehicles. Moreover, cost competitiveness will depend highly on future electricity and oil prices, and consumer willingness to pay extra for EVs compared to similar ICE vehicles. . Battery cost is the main bottleneck and, hence, a break-throw in battery technology lowering this cost would of course change the future map drastically in favor for electro-mobility in large.
4.2 Dissemination and exploitation of project results, and management of intellectual property
4.2.1 Exploitation of project results
Because of the consortium’s constitution along the value chain, the partners of the OPTIMORE project will together handle all exploitation related activities and IPR-issues.
Exploitation route
According to the ERTRAC road map , the future introduction of Electric Vehicles in the market will very strongly depend on the availability of functioning and cost efficient products from the suppliers. In their view, low-cost/weight motors and electronics should be available by 2012. Followed by optimized combustion engines for range extenders and highly integrated motors & controls by 2016. As the last milestone, mass production of highly integrated range extender systems should be a fact by 2018-2020.
Due to the fact that OPTMORE builds upon the FP7 FUEREX project, it’s work programme could very well run ahead of ERTRACs’ schedule, bridging the gap between milestone 2 (intermediate) and milestone 3 (mass production), herewith significantly supporting the early-market readiness of BEVs.
Exploitation interests partner group
Interest OEM partners [VOLVO, IVECO]
In December 2008 a new law was adopted: the new law nominally strives to reduce the average CO2 emissions from new cars to 130 g/km by 2015. Significantly the law adds a 95 g/km target for 2020, the “modalities” and “aspects of implementation” of which will be reviewed by the Commission in January 2013.
Carmakers are responsible for delivering the reductions. The company target is an average for all cars sold, not a fixed limit that no car may exceed. In this scenario, automotive manufacturers must seek and provide improved and innovative vehicle solutions to the open market which are not only compliant with the energy and environmental conditions and with the new law requirements, but also be competitive and increasingly appealing. In other words all the main global OEMs, including those based in Europe, are essentially being forced into finding new technological solutions to respect the social and environmental needs (environmental friendly vehicles) on one hand and on the other meet the demands of the customer (like higher levels of driveability and comfort, better safety and styling) at acceptable costs (in terms of purchase and operation costs as the price of fuel continues to increase).
Volvo and IVECO are committed towards meeting the targets for fleet average consumption of vehicles in Europe by 2020. One of the key technologies needed for this is electrification of vehicles as it shifts the propulsion system from fossil fuels. The reduction of European CO2 emissions is naturally dependent on the matter in which the electricity is produced. However, assuming a fossil free production of electricity this is a huge step forward. The successful introduction of electrified vehicles is strongly connected to the cost. Therefore Volvo and IVECO strongly believe that finding the right balance between battery capacity and range extender power is a key to finding the right cost. Modularity of the product is also a key to cost optimising the product. This is also one of the outputs from this project. The OEM partners will use the findings of this project to optimise the vehicles for maximum energy efficiency as well as cost in order to deliver an attractive product to the customer.
Interest supplier partners [AVL, Getrag]
The main interest of AVL is to sell leading engineering services and technologies especially to European Tier1 suppliers or OEMs which help to reduce CO2, emissions and NVH levels to comply with future legislation.
The service portfolio of AVL includes component, system development and software engineering. The rotary range extender and therewith OPTIMORE is a flagship for AVL regarding E-mobility. It is covering the integration of conventional technology with future key E-mobility elements to lower emissions at maximum in urban areas and to lower CO2 emissions generally as an enabler for E-vehicles in a wide application field. Currently it is a potential demonstration, 2015 the technology will be available for mass production, 2018 to 2020 the vehicles with highly integrated systems should be on the market. This business plan of AVL fits very well to the ERTRAC roadmap.
Interest knowledge providing partners [Chalmers, CRF]
CRF foresees different possible levels of exploitation concerning the Range Extender pack. The envisaged architecture is suitable not only for the specific application on BEV commercial vehicle, but also for other possible synergic utilizations that are concurring for the cost/volume industrialization targets; of course further exploitable results can be delivered during the progress of work. In the table below the plan is summarized (all generated in WP2):
Exploitable knowledge (description) Exploitable product(s) or measure(s) Sector(s) of application Time for commercial use Patents or other IPR protection
Specific management strategies Dedicated strategies integrated in the ECU RE pack tailored for small size Passenger Vehicles 2015 Pre-existing patents and patent application (CRF)
RE pack architecture Integrated Optimized Range Extender pack 1- Micro CHP (Combined Heat & Power) for off - road applications – i.e. industrial and domestic.
2- Series Hybrid for mid-High Size Passenger Vehicles 2016 Pre-existing patents and Patent applications (CRF, MM-PWT)
For universities the project should lead to the development of new insights and knowledge in several areas which will increase our innovation and development capacity. The new knowledge generated will be translated into new research ideas/projects but also used in education of PhD’s and Master students.
Chalmers has selected Transportation and Energy as two of its eight areas of advance and sustainable development as an overall focus, and this will means that the results from OPTIMORE will be used in a large research network.
• Swedish hybrid vehicle centre: Hosted by Chalmers and including the three Swedish vehicle OEMs and five universities.
• Combustion Engine Research Centre: a competence centre dedicated to development of environmental friendly and efficient combustion engines, including both university and industry.
• The Energy area of advance which include Hybrid and electric vehicles as one of the research themes.
Because of these networks, the results from OPTIMORE will be used by OEMs and researchers developing vehicles, but the knowledge will also be spread to researchers involved in other areas where the development of the vehicles is not the main focus but where understanding of the possibilities with range extender vehicles may be of importance for guiding their research and development. These other areas where OPTIMORE results may be very useful can be for instance life cycle studies of new transport solutions, development of recycling, development of new fuel and energy supply, Vehicle safety research or development of global energy and resource models.
The project has also generated good engineering examples which will be used in teaching. In this way, general engineering methodology can be covered at the same time as relevant environmental important aspects are covered.
4.2.2 Dissemination and exploitation
Within the Dissemination and Exploitation work package several deliverables are achieved in the first period, mainly setup of dissemination tools. The second period of the project was the execution of the dissemination activities and the monitoring of the exploitable results.
Public website
www.optimore-project.eu the project website was initiated at the beginning of the project and all project (public) results are available on the website.
(Peer) reviewed articles
From the results of the OPTIMORE project are in total six articles created and accepted by several journals and publishers.
The abstracts of these articles can be foud following the below link. Also included are the links to the publishers where the articles can be downloaded or purchased (if not free available).
http://www.optimore-project.eu/articles/peer-reviewed-articles.html
Flyer, Newsletters and other dissemination material
In total three newsletters are created from the project.
The first newsletter in the form of a general Flyer and distributed to all relevant stakeholders, using the dissemination database. The flyer is also published on the website as news item and under downloads.
The first newsletter was released after period 1. The newsletter was sent as an html mailing via e-mail and with reference to the downloadable items on the OPTIMORE website.
The second newsletter was released after the completion of the project and contains the following items:
- Final results, split into the 3 demonstrator vehicles and the results on the optimisation study from Chalmers and the functional safety. Short description in the newsletter with a reference and link to the more extended description on the public website
- Listing of all publications resulting from the research in the project
- Link to all deliverables from the project
- Results from the FINAL event
Further dissemination achievements
Final Workshop at Volvo
The final workshop was arranged in a two day workshop, with the first day afternoon an overview of all results from the OPTIMORE project followed by an evening event to further discuss the results. The second day was a gathering at the Volvo driving test track in Gothenburg, where the invited guests and the project partners could “experience” the driving in electric and electric Range Extender vehicles. Followed by a short workshop where the feedback from the participants was collected to further improve Range Extender vehicles in the near future.
Internal dissemination at OEM level
Within VOLVO/CRF/IVECO, the information was shared with relevant people in the design & test engineering departments in Europe, to evaluate how the outcome of the project could be implemented and be used to introduce OPTIMORE technology in Electric Vehicles across Europe and beyond.
List of Websites:
www.optimore-project.eu
