Final Report Summary - SOG PEERS (SOG Power Electronics with Energy Recycling System)
Executive Summary:
The Smart Operation on Ground (SOG) concept has appeared at the end of the 60’s, but technology was not efficient enough to allow introducing the concept. In 2012, it is not anymore the case, and this project aims to demonstrate the feasibility of an electrical solution. In this continuity, a french supplier of aircraft systems and equipment has decided to collaborate with AIR FRANCE in the development of the new system EGTS (Electric Green Taxiing System), an electrical device for taxiing the aircraft to roll over the tracks without using fuels. Based on initial analyzes, Air France evaluates a gain equivalent to a few percent of the fuel cost per flight cycle on the basis of its current operations for its fleet of over 120 aircraft short and medium haul.
This system uses an electric generator of the APU (Auxiliary Power Unit) to power the motors of the drive wheels, enabling the aircraft to move on the tracks without using the main engine. For this, each of these wheels is equipped with an electromechanical actuator and thanks to the power electronics and the control electronics of the wheels, the driver has complete control over the speed, direction and braking of aircraft on the ground.
SOG-PEERS (Smart Operation on Ground Power Electronics with Energy Recycling System) is a part of EGTS and is intended to electrically motorize the landing gear for short/medium haul plane (type Airbus A320 and Boeing737).
This electrical system must both recover and store the braking energy and secondly, to restore this energy during taxiing phases (before take-off and after landing, ie the phase when the aircraft is taxiing). This system will no longer use the aircraft engine thrust during the taxiing phases.
SOG-PEERS project involves several partners :
- The Topic Manager for system & integration activities on SOG project
- An English University for SOG electrical motor (wheel actuator) development
- A German laboratory for the modelisation and the development of system control laws.
- ADENEO which brings its expertise in conversion and energy storage environment constrained, and in management and monitoring / control of electrical actuators for the PEERS demonstrator.
SOG PEERS includes basic functions like forward and backward motion; moreover, it includes electrical braking, cruise control and energy braking recovery and storage. Stored energy will be managed to be used for example to supply emergency braking or emergency Landing Gear Extension Retraction System.
ADENEO has been working in different fields for motor control and has developed asynchronous and synchronous controllers hardware and software with the associated certification level in DO178 and DO254 currently for A350 XWB A/C. ADENEO is used to design embedded power converters. Starting 20 years ago with the railway industry, ADENEO brought it power electronic knowledge to aircraft industry to design converters for aircraft electrical networks. ADENEO has got significant experience in energy braking recovery, especially in light railway industry. By developing and testing embedded and stationary solutions, ADENEO has built strong experience, and now manages mature solutions that can be brought to aeronautic field. In railway industry, ADENEO has been selected to present NEOGREEN, its braking energy recovery product at the international Braking Energy Recovery workshop in Bielefeld of Ticket To Kyoto association in 2011. An embedded demonstrator has been tested in commercial service in Paris during 2 years, and a first NEOGREEN has been installed beginning of 2011 in Lyon tramway network. Based on this, ADENEO proposed in 2012 to develop a TRL4 demonstrator, based on internal COTS specially upgraded, to study the technical feasibility of the principle of energy recovery system on the EGTS (Electric Green Taxiing System) and a new super-capacitor technology.
More generally, the general objectives of SOG-PEERS which is part of a project electric taxiing are:
- Reduction in kerosene consumption of the aircraft;
- Noise reduction on the airport
- Increase the life of carbon brakes of the airplane (electric braking, so less stresses on these organs during the phases of "taxiing").
Project Context and Objectives:
ADENEO in collaboration with its partners, via the project SOG PEERS, wants to develop new electric taxiing solutions further efficient than the existing ones, notably in terms of energy efficiency. The main function of SOG PEERS equipment is to provide motive power to the landing gear wheels of an airliner to move on taxiways of an airport without start up the reactors.
The SOG PEERS project therefore includes an ability to recover braking energy in landing phase, and to reinject this electrical power at the time of the acceleration phase of the aircraft on ground. Energy saving allowing control the aircraft to the ground.
The SOG system consists of:
- Wheel actuators to provide mechanical torque and power to the wheels of the main landing gear. These actuators include wheel electric motors and transmissions, and are developed by the University
- Power electronic equipment (supported by PEERS) and control units for driving the actuators developed by Adeneo.
- System fitted on each wheel of the landing gear to ensure its drive and control independently developed by the Topic Manager
PEERS system, developed by Adeneo, is divided into two main parts:
- Power Electronic Unit (PEU), which drives the actuators of the wheel. It is composed mainly:
- Power Drive Units (PDU) which includes inverters, filters, etc. ;
- Control unit (CU), which manages the acquisition of data from engine sensors and embeds the control law. The CU will also acquire orders from senior controller SOG Controller system;
- Motor coupling function. The engine is still connected to the wheel of the aircraft (no clutch or reducer). This function allows you to bypass the motor phases during the landing and takeoff of the aircraft;
• PSU Power Supply Unit (PSU), which manages both the power from the network of the aircraft and the energy recovery system.
During acceleration phases, the PSU is providing power to the PEU in order to provide the needed motion torque to the aircraft thanks to the wheel actuators. This power may come from aircraft network or local energy storage device (LESD).
During braking phase, some regenerative power is transmitted from the Wheel Actuator Motors to the PEU and then, from the PEU to the PSU in the local energy storage device. Depending of the system status and configuration, the power may be:
- Stored in the local Energy storage device
- Burned in dedicated device (resistor, ...)
During aircraft landing or take off phases, the coupling function of the PEU disconnects the Wheel Actuator Motors to the PEERS. The coupling function of the PEU does a short-circuit between each power electrical connection of the wheel actuator.
EGTS objectives
The electrical taxiing system (EGTS) will provide many benefits such as:
- A reduced kerosene consumption of the aircraft during ground maneuvers : whereas taxiing traditional (use of reactors) on airports consumes a large volume of fuel - around 5 million tons per year for a short-haul flight - the electric taxiing system can generate savings of up to 4% fuel uplift
- A limitation of emissions nitric oxide (NOx) by 50% and carbon dioxide (CO2) 75% when aircraft is in taxiing
- Improved performance in terms of speed and autonomy during taxiing: the airplanes equipped with electric taxiing system will leave the boarding area autonomously and faster (length of pushback reduced by 60%), reducing the congested parking areas and tracks taxiing : departures on time and reduction of time on the ground
- Reducing of noise pollution at departure gates: the reactors are not on an optimum operating point during the taxiing phase, while these are the ones primarily responsible for noise pollution.
- Reducing maintenance by limiting the equipments (the system eliminates the need for tractors, towing equipment ...) and increasing the life of carbon brakes
Adeneo objectives
Adeneo is developing power devices with more and more power, in both conversion and storage activities. SOG-PEERS requires numerous converters and storage devices, with a complex management of all the energy transfers within these equipment. The main objectives for Adeneo in this project are the following :
- Development of an energy storage system based on a new technology of fast storage components, into weight and volume as low as possible.
- Development of a synchronous motor control with 2 stars. The constraint of this development is the low speed of the engine.
- Development of a PFC (Power Factor Convertor) converter with a power of 50KVA. This converter will be able to interface with the aircraft network.
- Study of an energy management approximating that of a hybrid vehicle.
- Development and manufacturing of a TRL4 demonstrator to prove the feasibility of this concept on a testbench simulating the real conditions for a landing aircraft on an airport.
The main features established for SOG-PEERS demonstrator are as follows
- System input power to the three phase power of the aircraft: 50kVA to allow the demonstrator to drive a SOG electrical motor
- Electrical engine power to drive : 50KVA
- Energy storage : nearly 500 000 Joules
- Weigh objectives for the final system : 100 Kg for all system – The weigh objective is not required for the TRL4 demonstrator.
Project Results:
The project was conducted in two main phases from October 2012 to May 2015.
- From September 2012 to April 2013 :
o System Specification & Preliminary Design in collaboration with the Topic manager
o Result : TRL3 review Green
- From May 2013 to October 2014 :
o Design, development & manufacturing of the PEU subassembly
o Result : Motor drive validation - PEU + SOG Electrical Engine in the laboratory of the University
- From October 2014 to May 2015 :
o Design, development & manufacturing of the PSU subassembly
o Electrical tests, integration and performance tests on PEERS demonstrator.
o Result : TRL4 review Green
The main activities and results of these phases are described in Periodic Reports ref: 7824A12 & 7824A15 submitted by Adeneo.
At the end of the project, main achievements are given below :
- The system validation had been performed on motor test bench
- The PEERS is able to drive the motor in both directions and in the four quadrants :
- The Sog-Control Unit dials with the PEERS and is able to drive it correctly
- The protections had been tested on the demonstrator and on the real time simulator for more complex tests
- The PEERS had been tested in endurance & the motor thermal behavior had been tested
- The running on dynamometer had been simulated on the real time simulator
- The demonstration was performed with the global system on “mobile testbench” in June 2015 in the laboratory of the Topic Manager.
So PEERS demonstrator is ready to perform demonstration on dynamometer.
On this project, the main S/T results for ADENEO are the following :
- Development of control laws for a double star motor running in low speed mode as well as the electronic power device which allows to drive this motor. Performance tests have been performed and are successful. This technological brick had never been developed in Adeneo before , and will be reused through another project for a embedded equipment in a submarine .
- Development of a supercapacitor storage module based on new fast storage components (Lithium Ion super capacitor) with all the management of the storage and the transfers of this energy. Power tests with charge & discharge cycles (endurance) have been performed with electrical loads and are successful. Performance tests have been performed with SOG motor and the behaviour of the system was good and compliant to the specification.
- Development of technological brick for PFC converter. This topology is able to be a rectifier or even an inverter. The simulations and the design take into account these two flows of power but for the demonstrator only the rectifier mode will be tested and validated.
- The use of Adeneo real time simulator to validate all subassemblies of PEERS. Initially, this simulator was developed for railways applications. For Sog-Peers project, Adeneo developed all the model to simulate a perfect environment of the equipment. All FPGA and software have been debugged with this simulation tool. Different tests have been done to check failure management and control laws. ADENEO has no electrical motor to verify the regulation. The verification of the regulation loops (speed and current) were performed on the NEO-SIM.
- For Adeneo, it was the first close collaborative work between ETI / University and industrial for an European project.
The demonstrator is oversized compared to the real need. In laboratory conditions, the demonstrator must be able to perform several tests in succession. While in case of actual use, the aircraft landed once therefore solicits the equipment only once. So, complementary to these results, Adeneo has performed optimization studies of the weight of the equipment and enabling to have a version of the PEERS which could be embedded in an airplane.This study has resulted in an optimization of the electrical architecture, and a modularity of sub-assemblies.
Initial estimates allow to get close to the goal of 100Kg with a system having the following main characteristics:
- 100kW nominal power with two double star motors driven separately.
- 850kJ energy storage available
It could be an input to the next step of the design (TRL5), associated to the definition of the safety criteria.
For ADENEO, 2 points are critical and must be taken account in the definition of the undesired events and the DAL for the PEERS:
- the WA coupling function during the landing and the take off the aircraft. The safety analysis could have an impact on the architecture.
- the monitoring of the super-capacitor to prevent over-charge of the cells.
Potential Impact:
Expected final results and potential impacts for Adeneo are the following
- Project results will be firstly devoted to aeronautical with the participation via Cleansky2 to the next step. Bring the gap from TRL4 demonstrator toward full TRL6 embedded equipment.
- Improving the maturity of Adeneo to address calls for proposal of CleanSky2 projects
- Improving the competitiveness of the energy storage markets with fast charge & discharge constraints
- Development of an innovative technological brick based on the architecture using the fast storage Lithium Ion super capacitor in railways domain.
- Re used of the super capacitor technology in energy storage for renewable energies
- Improving the PFC technological brick to increase the competitiveness of Adeneo in the field of renewable energies or in recycling energy technology.
- Participation in a collaborative project on the development of CEM simulation software for the standard DO160
- Promote the expertise and skills of Adeneo in hardware in the loop simulation and the real time simulator “NeoSim” developed by Adeneo for future aeronautic developments.
The dissemination activities are described in the attached file.
List of Websites:
Non applicable
The Smart Operation on Ground (SOG) concept has appeared at the end of the 60’s, but technology was not efficient enough to allow introducing the concept. In 2012, it is not anymore the case, and this project aims to demonstrate the feasibility of an electrical solution. In this continuity, a french supplier of aircraft systems and equipment has decided to collaborate with AIR FRANCE in the development of the new system EGTS (Electric Green Taxiing System), an electrical device for taxiing the aircraft to roll over the tracks without using fuels. Based on initial analyzes, Air France evaluates a gain equivalent to a few percent of the fuel cost per flight cycle on the basis of its current operations for its fleet of over 120 aircraft short and medium haul.
This system uses an electric generator of the APU (Auxiliary Power Unit) to power the motors of the drive wheels, enabling the aircraft to move on the tracks without using the main engine. For this, each of these wheels is equipped with an electromechanical actuator and thanks to the power electronics and the control electronics of the wheels, the driver has complete control over the speed, direction and braking of aircraft on the ground.
SOG-PEERS (Smart Operation on Ground Power Electronics with Energy Recycling System) is a part of EGTS and is intended to electrically motorize the landing gear for short/medium haul plane (type Airbus A320 and Boeing737).
This electrical system must both recover and store the braking energy and secondly, to restore this energy during taxiing phases (before take-off and after landing, ie the phase when the aircraft is taxiing). This system will no longer use the aircraft engine thrust during the taxiing phases.
SOG-PEERS project involves several partners :
- The Topic Manager for system & integration activities on SOG project
- An English University for SOG electrical motor (wheel actuator) development
- A German laboratory for the modelisation and the development of system control laws.
- ADENEO which brings its expertise in conversion and energy storage environment constrained, and in management and monitoring / control of electrical actuators for the PEERS demonstrator.
SOG PEERS includes basic functions like forward and backward motion; moreover, it includes electrical braking, cruise control and energy braking recovery and storage. Stored energy will be managed to be used for example to supply emergency braking or emergency Landing Gear Extension Retraction System.
ADENEO has been working in different fields for motor control and has developed asynchronous and synchronous controllers hardware and software with the associated certification level in DO178 and DO254 currently for A350 XWB A/C. ADENEO is used to design embedded power converters. Starting 20 years ago with the railway industry, ADENEO brought it power electronic knowledge to aircraft industry to design converters for aircraft electrical networks. ADENEO has got significant experience in energy braking recovery, especially in light railway industry. By developing and testing embedded and stationary solutions, ADENEO has built strong experience, and now manages mature solutions that can be brought to aeronautic field. In railway industry, ADENEO has been selected to present NEOGREEN, its braking energy recovery product at the international Braking Energy Recovery workshop in Bielefeld of Ticket To Kyoto association in 2011. An embedded demonstrator has been tested in commercial service in Paris during 2 years, and a first NEOGREEN has been installed beginning of 2011 in Lyon tramway network. Based on this, ADENEO proposed in 2012 to develop a TRL4 demonstrator, based on internal COTS specially upgraded, to study the technical feasibility of the principle of energy recovery system on the EGTS (Electric Green Taxiing System) and a new super-capacitor technology.
More generally, the general objectives of SOG-PEERS which is part of a project electric taxiing are:
- Reduction in kerosene consumption of the aircraft;
- Noise reduction on the airport
- Increase the life of carbon brakes of the airplane (electric braking, so less stresses on these organs during the phases of "taxiing").
Project Context and Objectives:
ADENEO in collaboration with its partners, via the project SOG PEERS, wants to develop new electric taxiing solutions further efficient than the existing ones, notably in terms of energy efficiency. The main function of SOG PEERS equipment is to provide motive power to the landing gear wheels of an airliner to move on taxiways of an airport without start up the reactors.
The SOG PEERS project therefore includes an ability to recover braking energy in landing phase, and to reinject this electrical power at the time of the acceleration phase of the aircraft on ground. Energy saving allowing control the aircraft to the ground.
The SOG system consists of:
- Wheel actuators to provide mechanical torque and power to the wheels of the main landing gear. These actuators include wheel electric motors and transmissions, and are developed by the University
- Power electronic equipment (supported by PEERS) and control units for driving the actuators developed by Adeneo.
- System fitted on each wheel of the landing gear to ensure its drive and control independently developed by the Topic Manager
PEERS system, developed by Adeneo, is divided into two main parts:
- Power Electronic Unit (PEU), which drives the actuators of the wheel. It is composed mainly:
- Power Drive Units (PDU) which includes inverters, filters, etc. ;
- Control unit (CU), which manages the acquisition of data from engine sensors and embeds the control law. The CU will also acquire orders from senior controller SOG Controller system;
- Motor coupling function. The engine is still connected to the wheel of the aircraft (no clutch or reducer). This function allows you to bypass the motor phases during the landing and takeoff of the aircraft;
• PSU Power Supply Unit (PSU), which manages both the power from the network of the aircraft and the energy recovery system.
During acceleration phases, the PSU is providing power to the PEU in order to provide the needed motion torque to the aircraft thanks to the wheel actuators. This power may come from aircraft network or local energy storage device (LESD).
During braking phase, some regenerative power is transmitted from the Wheel Actuator Motors to the PEU and then, from the PEU to the PSU in the local energy storage device. Depending of the system status and configuration, the power may be:
- Stored in the local Energy storage device
- Burned in dedicated device (resistor, ...)
During aircraft landing or take off phases, the coupling function of the PEU disconnects the Wheel Actuator Motors to the PEERS. The coupling function of the PEU does a short-circuit between each power electrical connection of the wheel actuator.
EGTS objectives
The electrical taxiing system (EGTS) will provide many benefits such as:
- A reduced kerosene consumption of the aircraft during ground maneuvers : whereas taxiing traditional (use of reactors) on airports consumes a large volume of fuel - around 5 million tons per year for a short-haul flight - the electric taxiing system can generate savings of up to 4% fuel uplift
- A limitation of emissions nitric oxide (NOx) by 50% and carbon dioxide (CO2) 75% when aircraft is in taxiing
- Improved performance in terms of speed and autonomy during taxiing: the airplanes equipped with electric taxiing system will leave the boarding area autonomously and faster (length of pushback reduced by 60%), reducing the congested parking areas and tracks taxiing : departures on time and reduction of time on the ground
- Reducing of noise pollution at departure gates: the reactors are not on an optimum operating point during the taxiing phase, while these are the ones primarily responsible for noise pollution.
- Reducing maintenance by limiting the equipments (the system eliminates the need for tractors, towing equipment ...) and increasing the life of carbon brakes
Adeneo objectives
Adeneo is developing power devices with more and more power, in both conversion and storage activities. SOG-PEERS requires numerous converters and storage devices, with a complex management of all the energy transfers within these equipment. The main objectives for Adeneo in this project are the following :
- Development of an energy storage system based on a new technology of fast storage components, into weight and volume as low as possible.
- Development of a synchronous motor control with 2 stars. The constraint of this development is the low speed of the engine.
- Development of a PFC (Power Factor Convertor) converter with a power of 50KVA. This converter will be able to interface with the aircraft network.
- Study of an energy management approximating that of a hybrid vehicle.
- Development and manufacturing of a TRL4 demonstrator to prove the feasibility of this concept on a testbench simulating the real conditions for a landing aircraft on an airport.
The main features established for SOG-PEERS demonstrator are as follows
- System input power to the three phase power of the aircraft: 50kVA to allow the demonstrator to drive a SOG electrical motor
- Electrical engine power to drive : 50KVA
- Energy storage : nearly 500 000 Joules
- Weigh objectives for the final system : 100 Kg for all system – The weigh objective is not required for the TRL4 demonstrator.
Project Results:
The project was conducted in two main phases from October 2012 to May 2015.
- From September 2012 to April 2013 :
o System Specification & Preliminary Design in collaboration with the Topic manager
o Result : TRL3 review Green
- From May 2013 to October 2014 :
o Design, development & manufacturing of the PEU subassembly
o Result : Motor drive validation - PEU + SOG Electrical Engine in the laboratory of the University
- From October 2014 to May 2015 :
o Design, development & manufacturing of the PSU subassembly
o Electrical tests, integration and performance tests on PEERS demonstrator.
o Result : TRL4 review Green
The main activities and results of these phases are described in Periodic Reports ref: 7824A12 & 7824A15 submitted by Adeneo.
At the end of the project, main achievements are given below :
- The system validation had been performed on motor test bench
- The PEERS is able to drive the motor in both directions and in the four quadrants :
- The Sog-Control Unit dials with the PEERS and is able to drive it correctly
- The protections had been tested on the demonstrator and on the real time simulator for more complex tests
- The PEERS had been tested in endurance & the motor thermal behavior had been tested
- The running on dynamometer had been simulated on the real time simulator
- The demonstration was performed with the global system on “mobile testbench” in June 2015 in the laboratory of the Topic Manager.
So PEERS demonstrator is ready to perform demonstration on dynamometer.
On this project, the main S/T results for ADENEO are the following :
- Development of control laws for a double star motor running in low speed mode as well as the electronic power device which allows to drive this motor. Performance tests have been performed and are successful. This technological brick had never been developed in Adeneo before , and will be reused through another project for a embedded equipment in a submarine .
- Development of a supercapacitor storage module based on new fast storage components (Lithium Ion super capacitor) with all the management of the storage and the transfers of this energy. Power tests with charge & discharge cycles (endurance) have been performed with electrical loads and are successful. Performance tests have been performed with SOG motor and the behaviour of the system was good and compliant to the specification.
- Development of technological brick for PFC converter. This topology is able to be a rectifier or even an inverter. The simulations and the design take into account these two flows of power but for the demonstrator only the rectifier mode will be tested and validated.
- The use of Adeneo real time simulator to validate all subassemblies of PEERS. Initially, this simulator was developed for railways applications. For Sog-Peers project, Adeneo developed all the model to simulate a perfect environment of the equipment. All FPGA and software have been debugged with this simulation tool. Different tests have been done to check failure management and control laws. ADENEO has no electrical motor to verify the regulation. The verification of the regulation loops (speed and current) were performed on the NEO-SIM.
- For Adeneo, it was the first close collaborative work between ETI / University and industrial for an European project.
The demonstrator is oversized compared to the real need. In laboratory conditions, the demonstrator must be able to perform several tests in succession. While in case of actual use, the aircraft landed once therefore solicits the equipment only once. So, complementary to these results, Adeneo has performed optimization studies of the weight of the equipment and enabling to have a version of the PEERS which could be embedded in an airplane.This study has resulted in an optimization of the electrical architecture, and a modularity of sub-assemblies.
Initial estimates allow to get close to the goal of 100Kg with a system having the following main characteristics:
- 100kW nominal power with two double star motors driven separately.
- 850kJ energy storage available
It could be an input to the next step of the design (TRL5), associated to the definition of the safety criteria.
For ADENEO, 2 points are critical and must be taken account in the definition of the undesired events and the DAL for the PEERS:
- the WA coupling function during the landing and the take off the aircraft. The safety analysis could have an impact on the architecture.
- the monitoring of the super-capacitor to prevent over-charge of the cells.
Potential Impact:
Expected final results and potential impacts for Adeneo are the following
- Project results will be firstly devoted to aeronautical with the participation via Cleansky2 to the next step. Bring the gap from TRL4 demonstrator toward full TRL6 embedded equipment.
- Improving the maturity of Adeneo to address calls for proposal of CleanSky2 projects
- Improving the competitiveness of the energy storage markets with fast charge & discharge constraints
- Development of an innovative technological brick based on the architecture using the fast storage Lithium Ion super capacitor in railways domain.
- Re used of the super capacitor technology in energy storage for renewable energies
- Improving the PFC technological brick to increase the competitiveness of Adeneo in the field of renewable energies or in recycling energy technology.
- Participation in a collaborative project on the development of CEM simulation software for the standard DO160
- Promote the expertise and skills of Adeneo in hardware in the loop simulation and the real time simulator “NeoSim” developed by Adeneo for future aeronautic developments.
The dissemination activities are described in the attached file.
List of Websites:
Non applicable