CORDIS - EU research results

A Platform Power Management System and Low Voltage Drive Train for Hybrid and Electric Vehicles

Final Report Summary - SAFEDRIVE (A Platform Power Management System and Low Voltage Drive Train for Hybrid and Electric Vehicles)

Executive Summary:

Safedrive is a development project that is funded under European Commission Seventh Framework programme for the benefit of SME associations. The Safedrive project proposed an initiative to develop an electric vehicle drive train incorporating a novel modular motor design, a Split-Pi DC to DC converter together with a power management and distribution system. This technology is designed to be utilised in pure electric and hybrid-electric vehicles. One of the main features of the research was the development of a modular DC motor which is constructed with materials that are easily accessible negating the need to source rare-earth magnetic material such as neodymium. The torque characteristic of the motor under development has a target value of 800-1200nm. This would eliminate the requirement for a gearbox allowing direct drive via drive shaft or as a hub motor.

Another aspect of the project was the development of a highly efficient bi-directional DC to DC converter which is located in the drivetrain between the power sources and the modular motors. The power sources will be super capacitor, lithium Ion batteries and a motor-generator set.

SME electric and hybrid vehicle manufacturers within Europe are the main beneficiaries of the technology developed in this project and will gain from being able to access open source drive train components which could reduce their costs and provide them with similar benefits to the larger vehicle manufacturers who have the advantage of mass production and the sharing of vehicle platform technology.

The project consortium consists of SME association groups, SME end user manufacturers, SME supply chain partners and RTD performers. These organisations were drawn from many countries within Europe including UK, Belgium, France, Switzerland, Spain, Croatia and Czech Republic.

Project Context and Objectives:

The objectives of the Safedrive project are based around the requirements of the European SME hybrid, electric and fuel cell industry. This industry represents around 1,600 manufacturers and suppliers. The current difficulty for these organisations is the lack of a common drive train platform which could be adapted to fit specialised applications. This puts them at a disadvantage when competing with the larger multinational vehicle manufacturers who dominate the vehicle market.

The aim of this project is to create a means for European SME electric vehicle manufacturers to make inroads into the electric vehicle market and close the gap that exists. The project proposes to develop an electric drivetrain which is modular and scalable and can be adapted to suit a wide range of electric/hybrid vehicle applications. These include small cars, heavy goods and utility vehicles.

The main objectives were as follows:

• Characterisation and Modelling
• Research and simulation of control


• Motor theory validation and principle design
• Development and prototype of the power

Management systems

• Development and prototype of the motor mechanical and power electronics systems
• Technology Integration
• Testing and Validation
• Knowledge transfer and training
• Innovation and exploitation activities

Project Results:

The Safedrive project achievement to date are as follows: the consortium partners have performed research into existing technologies, developed control algorithms for controlling the power distribution in the drive train, developed and implement the modular motor theory in the laboratory, developed a novel method for producing high current carrying circuit boards using a copper thermal spraying technology

The final stage of the project will be to integrate the individual developments onto a prototype platform in order to demonstrate the results and achievement of the project. This work has continued during period 3 and is nearing completion.

In the third period, the work that had been performed during the previous two periods was built up on and it provided the base information for the designs of the drive train component parts. Taking each component in turn, the development progressed as follows:

The modular DC motor design has been divided into three developments. The first being a small version of the motor consisting of two flux return rings and a rotor. A set of slip rings were used to supply the current to the rotor. Steel segment were used to create the magnetic fields in the rotors and flux return rings. Later versions of the motor will used a soft magnetic material called Somaloy.

This first prototype was developed in order to prove the mechanical integrity of the design before moving quickly onto the fully size motor design. A large proportion of the CAD design work for the full size motor was performed for the first prototype.

The small motor was produced successfully and displayed at the Geneva motor Show in March 2013. Laboratory tests on the motor were also performed to gain some preliminary results of future performance.

A full size 4-gap motor was constructed shortly afterwards and this was extensively tested in the laboratory on a dynamometer. This motor consisted of 6 rotor and stator/flux return ring pairs. Steel segments were again used in this version of the motor.

The complex motor switching circuitry has been designed and produced in order to provide the required commutation for the motor. This included firmware development and testing. A basic switching module was implemented for the small prototype motor and the circuitry was upgraded to supply the switching for the full size motor

In the third phase of the motor development, the small prototype motor was redesigned and built using the Somaloy soft magnetic material in the rotors, stator and flux return rings. Using this material would improve the operations of the motor and enable it run at higher rotational speeds and be able to produce the required torque.

The Split Pi DC to DC consists of several PCBs forming the eight phases that are required to drive a full size motor. Circuit diagrams and PCB layouts have been produced and the manufacture of the first prototype module has taken place during period three. Testing has been performed and results have been gained. From the initial findings, another development stage is required in order for the full eight phase converter to operating with the modular motor and test its drive capabilities.

The power management module has be developed and tested and it will be ready to integrate with the other drivetrain components during the integration phase together with the transmission cabling which have been specified. A switching matrix has been designed and developed which is the interface between the power management system and the Split-Pi DC to DC converter. The power transfer between the multiple power sources within an electric vehicle can be controlled when these modules are integrated. A system to manage the Lithium Ion batteries has also been developed as part of the integration.

The consortium has worked hard to disseminate Safedrive throughout the whole duration of the project. Highlights have been EVS26, USA and IAMF, Geneva in period two of the project and the Geneva motor show and EVS27 during period three of the project. Several other events have also been attended by members of the consortium and Safedrive has been publicised n partner websites and in publications.

Potential Impact:

The expected final result of the project will be a fully functional electric vehicle drive train incorporating an innovative modular DC motor able to produce a torque as specified, an 8 phase Split-Pi DC to DC converter capable of supplying the motor with current from Lithium Ion Batteries, Super capacitors, motor-generator set or other in-vehicle DC supply. The power management of the drive train will be controlled by a dedicated power controller with a user interface. The interface between the power management and the Dc-Dc converter will be a switching matrix.

The results of this project will be of great benefit to the electric and hybrid vehicle market and increase the access to electric vehicle for larger range of people.

For example, a modular in-hub motor will allow the development of low-floored buses for city centre use improving access for the disabled and infirm.

The low standing voltage of the vehicle will eliminate the electrical hazard which is present on many of the current electric and hybrid vehicles available today. There will also be environmental benefits with a reduction in vehicle exhaust gas emissions

The open source nature of the project results will enable SME manufacturers to access the technology which will be more cost effective for their businesses and allow them to develop into other areas.

The consortium has worked hard to disseminate Safedrive throughout the whole duration of the project. Highlights have been EVS26, USA and IAMF, Geneva in period two of the project and the Geneva motor show and EVS27 during period three of the project. Several other events have also been attended by members of the consortium and Safedrive has been publicised partner websites and in publications. Dissemination material used by project partners includes a project pull-up banner, information flyers and a project poster. The website which is fully accessible has provided information to a wider audience.

List of Websites:

The project website can be found at the following web address

The details of the main contacts for the Safedrive are shown below:

Project Coordinator:
Mr Angel Aghili
Pleinlaan 2
1050 Brussel
Tel. + 32 (0)2-629 2363

Project Exploitation Manager:
Mr Robert Kybird
Green Energy Technologies Ltd
39 Marsh Green Road West,
Marsh Barton,
Exeter, EX2 8PN,
United Kingdom
Tel: +44(0)845 6432194

Project Manager:
Mr Orlando Davy
UK intelligent Systems
Research Institute
Nottingham Road
Melton Mowbray
LE13 0PB
United Kingdom
Tel: +44(0)1664 501501