EPE Association: EPE 2009 - Subtopic 17-9 - DS: 'Power Electronics for Transport Applications'

EPE 2009 - Subtopic 17-9 - DS: 'Power Electronics for Transport Applications'
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2009 - Conference > EPE 2009 - Topic 17: 'Electrical Systems in Aerospace, Space, Surface and Marine Transport' > EPE 2009 - Subtopic 17-9 - DS: 'Power Electronics for Transport Applications'

   [return to parent folder]

   A components library for simulation and analysis of aircraft electrical power systems using modelica
By Martin KUHN, Antonio GRIFFO, Jiabin WANG, Johann BALS [View]
[Download]

Abstract: A library of components for simulation and analysis of large vehicular electrical power systems using Modelica language is presented. Components are described using different levels of model complexity, catering for both detailed high fidelity transient switching dynamics and averaged value descriptions which, being time invariant, are a computationally efficient and useful tool for design, stability and sensitivity analyses. The merits of employing the Modelica based modelling tool are discussed, and its utilities and effectiveness are demonstrated through a test system consisting of a three-phase, variable frequency synchronous generator which feeds high voltage DC loads via an auto-transformer rectifier unit.

   A Multi-level Simulation using VHDL-AMS and Coupled Analysis for an Alternator Regeneration System in a Vehicle
By Shinji YAMAMOTO, Takashi ABE, Tsuyoshi HIGUCHI, Kimitoshi TSUJI [View]
[Download]

Abstract: Recent innovation in vehicle systems has brought the extensive application of power electronics (PE) technology, which in turn has made the system more complex. The vehicle system is a multi-domain system, so that computer simulation has become an indispensable tool for vehicle system analysis. We propose a simulation method for the complex vehicle system based on the VHDL-AMS language. A multi-level modeling technique for an alternator regeneration system is also proposed using VHDL-AMS and coupled analysis with the aim of analyzing the simulation of the regeneration system in detail.

   A Power Line Communication Approach for Body Electronics Modules
By Antonio TESTA, Salvatore DE CARO, Romeo LETOR [View]
[Download]

Abstract: Body electronics systems are pervasively spreading all over modern vehicles making cars easy to operate, relieving drivers from several minor tasks and improving safety and comfort. These systems are connected between them and to peripheral control units through networks based on serial protocols. Cost reductions can be accomplished by adopting Power Line Communication techniques, to enable existing power cables to provide the physical layer for communication. An investigation about a power line communication system dedicated to body electronics applications is presented in this paper. The concept and the methods used for data transmission from a master to some slave nodes are described and the design of a transceiver retaining the logic of the LIN protocol and allowing data transfer through power cables is then discussed. Cost and EMC issues are also considered. A prototype power line network has been realized and tested.

   constant power cycling for accelerated ageing of supercapacitors
By Paul KRECZANIK, Pascal VENET, Guy CLERC, Christian MARTIN, Gerard ROJAT, Younes ZITOUNI [View]
[Download]

Abstract: This paper deals with the lifetime of supercapacitors used in transportation. Increasing onboard electrical devices require adapted storage elements like supercapacitors to supply all electrical systems. Reliability and lifetime are two major factors for electrical storage system. Based on accelerated ageing, some supercapacitors have been studied using a dedicated test bench. Temperature, voltage, current and power cycling are monitored since supercapacitor ageing are affected by these parameters. An ageing law suitable for a transport application is obtained and discussed.

   Develop of a Marine Diesel Particulate Filter (M-DPF) Applied for High Frequency Induction Heating
By yosuke FUKUOKA [View]
[Download]

Abstract: Novel marine diesel particulate filter (M-DPF) applied for high frequency induction heating is useful system in which particulate matter (PM) exhausted from marine diesel engine is trapped on the surface of the metallic fiber filter and is effectively burned and regenerated by high frequency induction heating. For efficient PM trapping and regeneration of the DPF, the construction on substance of the filter is crucial importance. From the design point of view, some types of DPF such as cylindrical type and pleated type are experimentally examined for PM reduction system and the performance as DPF is investigated. Trapped PM on the metallic fiber filter is successfully burned off by high frequency induction heating unit which is composed of a new working coil and high frequency power supply.

   Efficient Simulation Method for Comparison of Brush and Brushless DC Motors for Light Traction Application
By Geraldo SINCERO, Jerome CROS, Philippe VIAROUGE [View]
[Download]

Abstract: This work presents modeling and simulation method to evaluate performance of light traction systems. This method is well adapted to study permanent magnet brushed and brushless dc motor drives, as it presents a general modeling approach for the commutator and armature of permanent magnet synchronous machines. Two types of commercial motor drives for electric scooters are analyzed and compared.

   Enabling pressure tolerant power electronic converters for subsea applications
By MAGNAR HERNES, RICCARDO PITTINI [View]
[Download]

Abstract: This paper present result from an on-going research project on pressure tolerant power electronics where the power electronic components are enabled to operate in a pressurized dielectric environment. The driving force for the research is to provide new solutions for subsea high power converters that can get benefits by reduced weight and volume of pressure chambers, reduced number of electric power penetrators, obtain less complexity and more reliable cooling system, reduced costs and increased overall reliability. The components of most concern have been power semiconductors, power capacitors and IGBT gate drivers. Even though the work reported in this paper is still in progress, the basic investigations and experimental work so far indicates that reliable solutions for pressure tolerant power electronics has a high potential for success, when all power components and gate driver electronics are vacuumized and soaked in a proper dielectric fluid. This is valid for the individual components as well as for the complete circuits. Also the feedbacks from the components manufacturers are uplifting in that respect.

   Flatness based control of a fuel cell-supercapacitor multi source/multi load hybrid system
By Alireza PAYMAN, serge PIERFEDERICI, farid MEIBODY-TABAR, bernard DAVAT [View]
[Download]

Abstract: This paper presents the flatness based control of a multi-source/multi-load electrical hybrid system (EHS) composed of a fuel cell and a supercapacitor-bank (SCB) as the main and auxiliary source, respectively. The main and auxiliary sources are connected to a DC link which has a floating voltage. This DC-power source supplies three independent 5V, 12V and 24V loads which are connected to the DC link through different buck converters. A flatness based method is used in this paper to control the hybrid system. For this purpose, the electrostatic energy stored on the DC link and also output capacitors are considered as the flat outputs of the system. Then, different reference trajectories are planned on these outputs and they are forced to track their references. The dynamics of fuel cell is limited by controlling the DC link voltage variation which is carried out by putting a filter on the reference of DC link trajectory. The proposed method does not contain commutation algorithm whereas the different operating modes exist. The implementation results are presented to validate operation of the proposed method in the multi source/multi load hybrid system.

   Hybrid Drive System of an Industrial Truck Using a Three-Phase DC-DC Converter Feeding Ultra-Capacitors
By Christian RUDOLPH [View]
[Download]

Abstract: The diesel-electric drive system of an industrial truck is extended with an energy storage subsystem utilizing ultra-capacitors thus establishing a reliable technical solution with a great energy saving potential. A bidirectional three-phase DC-DC converter is proposed to charge the ultra-capacitors during the regenerative braking of the electric drive and to discharge them when peak power is demanded. The developed DC-DC converter uses three-phase coupled inductors for filtering its phase and output currents. The presented current-control for the DC-DC converter is both effective and easy to implement. Practical results show that the DC-DC converter operates reliably in the laboratory as well as in the hybrid drive system of industrial trucks. Depending on the field of application for the industrial truck, total energy savings of ten to twenty percent are possible.

   Model-based sensorless control of a SPM Synchronous Motor Drive for a Hybrid Catamaran
By Silverio BOLOGNANI [View]
[Download]

Abstract: The paper deals with a sensorless control of a Permanent Magnet synchronous motor drive for a hybrid electric catamaran. A Surfaceâ€“mounted Permanent Magnet motor has been chosen and a distinctive sensorless control of this machine is deeply described. Control performance is validated by simulation and experimental results. Start-up mode, reversal of speed and synchronization lost occurrence will be specifically treated.

   Modeling and Simulation of Marine On-board Electrical Network
By Pedro Neiva KVIESKA, Mourad AÃT-AHMED, Guy LEBRET, Gang YAO [View]
[Download]

Abstract: This paper presents detailed models and simulators for an electrical on-board marine network. A one machine network is considered, and loads are described, initially, as equivalent RL circuits based on active and reactive powers, which results in a 5th order dynamic system. Then a more refined model with capacitances is proposed, which results in a 9th order dynamic system. This model represents the network in a simple and yet realistic way. The behavior of this system for different load situations leads to a load classification that is briefly discussed. To perfectly know the conditions of the load commutations that are being analyzed, electrical simulators were developed in the Matlab/Simulink environment. Both simulators, for each one of the load models are here described. The RL simulator presents a very good performance, and the RLC a very large range of adaptability.

   Novel Voltage Balancer forElectric Double Layer Capacitor by Using CW circuit
By Keiju MATSUI, Hiroto SHIMADA, Masaru HASEGAWA, Takayoshi SUZUKI [View]
[Download]

Abstract: EDLCs (Electric Double Layer Capacitors) offer high energy density and long life span, so various applications may be anticipated in the realm of energy storage devices, such as those used in electric vehicles or electric power stabilisation in power systems, etc. However, since the voltage limit is low of the devices, it is necessary to connect them in series or parallel. In addition, it is required that they be used in the region of their critical voltage limit or capacity limit. In order to apply them efficiently, the devices should be use with balanced voltage. Firstly, the authors discuss a conventional method, for example using a forward converter, etc. In a second approach, a novel voltage balancer is presented, employing a CW(Cockcroft-Walton) circuit. Characteristics of proposed circuit are analized and discussed.

   Power Electronics Interface for an Hybrid PEMFC Generating System with Fault Management Strategies for Transportation
By Alexandre DE BERNARDINIS, Denis CANDUSSO, Fabien HAREL, GÃ©rard COQUERY [View]
[Download]

Abstract: This paper presents a fault tolerant power electronics interface used in an hybrid PEM Fuel Cell generating system for transportation. A battery plays the role of an energy buffer on the DC link. Anti-parallel bypass diodes are used to isolate a defective fuel cell module. An interleaved boost converter with backup strategies realizes the electrical interface. The diode derivation circuit and the electrical converter can ensure uninterrupted power delivery and fault management. Simulations with degraded working modes for the fuel cell and power converter are presented and the diode bypass function is experimentally validated on a 20-cell 500W PEM fuel cell stack.

   Rapid Modelling and Design of Variable Speed Permanent Magnet Generators for Maritime Applications
By Juan Marcelo GUTIERREZ ALCARAZ, Nada AL-FARTUSI, Henk POLINDER, J.A. FERREIRA [View]
[Download]

Abstract: Electrical power generation plays an important role in maritime vessels. This power is usually provided by a multi-component system where the generation begins with the rotational movement of a prime mover, usually and Internal Combustion Engine, an electric generator and an assortment of power electronic components to process and regulate electrical energy. Due to the requirements of the application, i.e. power-on-demand to reduce fuel consumption and increase user comfort, all components need to be adapted to perform efficiently within a wide range of output power levels. For such a purpose a Variable Speed Permanent Magnet Generator (VSPMG) is presented as a solution that fulfills most of the requirements of the power generation stage. However, the design of such of generator is a long process where multiple variables intervene. The following paper deals with a rapid modelling and design tool that helps evaluate a VSPMG with concentrated windings in a quick, and relatively accurate, manner. This tool can be used to obtain a first draft design that can be perfected after further analysis. Analytical equations and experimental data are presented for validation. A simplified thermal model is also presented with the corresponding experimental counterpart. Finally, conclusions are given and next steps are suggested.

   Some Considerations Concerning the Distribution of Electrical Energy in a Low Voltage System
By Petre-Marian NICOLAE, Lucian MANDACHE, Ileana-Diana NICOLAE, Ioana-Gabriela SIRBU [View]
[Download]

Abstract: One presents the main disturbances sources from the distribution substations used for urban electric transportation systems: transformers from substations; three-phase supplying line; converters from substations; contact line and path rails. Using a quality analyzer, numerical recordings are obtained representing the waveforms of voltages and currents in a substation for the transformation medium to low voltage. The recorded data are transferred to a PC and processed, based on an original decomposition algorithm that implements the Fast Fourier Transform (FFT). The study case refers to a global consumption of a substation with an approximate active power of 590 kW and reactive power 65 kVAr. Harmonic decompositions of the recorded voltages and currents are made. One computes a series of quantities characteristic to the analyzed distorting regime (RMS values, total harmonic distortion for the phase voltages and phase currents, a.o.). The waveforms are afterward recomposed revealing that the computation error introduced by the decomposition algorithm is very small. The phases (re)active powers and total powers are determined. Interpretations of the determined values are provided. The analysis reveals the necessity to create a dedicated data acquisition system for each transformation substation in order to provide a complete monitoring system. Also should be useful the development of some real time recording and processing systems to realize a compensation efficient both from the distorting regime point of view and respectively from the compensation along the fundamental harmonic.

   THE ENERGY STORAGE SYSTEM FOR PUBLIC TRANSPORT
By Lubos STREIT, Pavel DRABEK [View]
[Download]

Abstract: This paper presents research motivated by industrial demand for energy storage system for city transport vehicles. Our city transport has problems with stability of the trolley line voltage at the several places in the city a therefore this research has been started. Energy storage system with supercapacitors is one solution. The kinetic energy is accumulated into the supercapacitor during vehicle braking. This energy can be used to accelerating again. It is important to save the energy in the vehicles, which accelerate very often (we can think about stabile or mobile version).

   The Stability Analysis of AC-DC Systems Including Actuator Dynamics for Aircraft Power Systems
By KONGPAN AREERAK, Serhiy BOZHKO, Greg ASHER, LILIANA DE LILLO, ALAN WATSON, Tao WU, Dave THOMAS [View]
[Download]

Abstract: This paper presents the small-signal stability analysis of AC-DC power system taking into account dynamics of electromechanical actuator (EMA). A dq modelling method is employed to predict unstable operation caused by possible variations in operating points and/or system parameters. The obtained theoretical results are supported by intensive simulations and verified experimentally.

   Weight and Efficiency Optimization Strategy of an interleaved DC-DC Converter for a Solar Aircraft
By Yannick LOUVRIER, Philippe BARRADE, Alfred RUFER [View]
[Download]

Abstract: Today, energy saving is one of the main objectives for engineers. In the case of mobile applications, energy can be saved by two different ways. First, decreasing the total masse of the system, and second, increasing the efficiency of the overall system.This paper presents an optimization strategy to design an interleaved DC/DC converter in order to find the best compromise between efficiency, weight and current inductor ripple. The strategy of this method also lends itself well to find the right split power level that must by selected to obtain the best efficiency and weight power density of a given application.

EPE 2009 - Subtopic 17-9 - DS: 'Power Electronics for Transport Applications'
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2009 - Conference > EPE 2009 - Topic 17: 'Electrical Systems in Aerospace, Space, Surface and Marine Transport' > EPE 2009 - Subtopic 17-9 - DS: 'Power Electronics for Transport Applications'
	[return to parent folder]

	A components library for simulation and analysis of aircraft electrical power systems using modelica By Martin KUHN, Antonio GRIFFO, Jiabin WANG, Johann BALS	[View] [Download]
Abstract: A library of components for simulation and analysis of large vehicular electrical power systems using Modelica language is presented. Components are described using different levels of model complexity, catering for both detailed high fidelity transient switching dynamics and averaged value descriptions which, being time invariant, are a computationally efficient and useful tool for design, stability and sensitivity analyses. The merits of employing the Modelica based modelling tool are discussed, and its utilities and effectiveness are demonstrated through a test system consisting of a three-phase, variable frequency synchronous generator which feeds high voltage DC loads via an auto-transformer rectifier unit.

	A Multi-level Simulation using VHDL-AMS and Coupled Analysis for an Alternator Regeneration System in a Vehicle By Shinji YAMAMOTO, Takashi ABE, Tsuyoshi HIGUCHI, Kimitoshi TSUJI	[View] [Download]
Abstract: Recent innovation in vehicle systems has brought the extensive application of power electronics (PE) technology, which in turn has made the system more complex. The vehicle system is a multi-domain system, so that computer simulation has become an indispensable tool for vehicle system analysis. We propose a simulation method for the complex vehicle system based on the VHDL-AMS language. A multi-level modeling technique for an alternator regeneration system is also proposed using VHDL-AMS and coupled analysis with the aim of analyzing the simulation of the regeneration system in detail.

	A Power Line Communication Approach for Body Electronics Modules By Antonio TESTA, Salvatore DE CARO, Romeo LETOR	[View] [Download]
Abstract: Body electronics systems are pervasively spreading all over modern vehicles making cars easy to operate, relieving drivers from several minor tasks and improving safety and comfort. These systems are connected between them and to peripheral control units through networks based on serial protocols. Cost reductions can be accomplished by adopting Power Line Communication techniques, to enable existing power cables to provide the physical layer for communication. An investigation about a power line communication system dedicated to body electronics applications is presented in this paper. The concept and the methods used for data transmission from a master to some slave nodes are described and the design of a transceiver retaining the logic of the LIN protocol and allowing data transfer through power cables is then discussed. Cost and EMC issues are also considered. A prototype power line network has been realized and tested.

	constant power cycling for accelerated ageing of supercapacitors By Paul KRECZANIK, Pascal VENET, Guy CLERC, Christian MARTIN, Gerard ROJAT, Younes ZITOUNI	[View] [Download]
Abstract: This paper deals with the lifetime of supercapacitors used in transportation. Increasing onboard electrical devices require adapted storage elements like supercapacitors to supply all electrical systems. Reliability and lifetime are two major factors for electrical storage system. Based on accelerated ageing, some supercapacitors have been studied using a dedicated test bench. Temperature, voltage, current and power cycling are monitored since supercapacitor ageing are affected by these parameters. An ageing law suitable for a transport application is obtained and discussed.

	Develop of a Marine Diesel Particulate Filter (M-DPF) Applied for High Frequency Induction Heating By yosuke FUKUOKA	[View] [Download]
Abstract: Novel marine diesel particulate filter (M-DPF) applied for high frequency induction heating is useful system in which particulate matter (PM) exhausted from marine diesel engine is trapped on the surface of the metallic fiber filter and is effectively burned and regenerated by high frequency induction heating. For efficient PM trapping and regeneration of the DPF, the construction on substance of the filter is crucial importance. From the design point of view, some types of DPF such as cylindrical type and pleated type are experimentally examined for PM reduction system and the performance as DPF is investigated. Trapped PM on the metallic fiber filter is successfully burned off by high frequency induction heating unit which is composed of a new working coil and high frequency power supply.

	Efficient Simulation Method for Comparison of Brush and Brushless DC Motors for Light Traction Application By Geraldo SINCERO, Jerome CROS, Philippe VIAROUGE	[View] [Download]
Abstract: This work presents modeling and simulation method to evaluate performance of light traction systems. This method is well adapted to study permanent magnet brushed and brushless dc motor drives, as it presents a general modeling approach for the commutator and armature of permanent magnet synchronous machines. Two types of commercial motor drives for electric scooters are analyzed and compared.

	Enabling pressure tolerant power electronic converters for subsea applications By MAGNAR HERNES, RICCARDO PITTINI	[View] [Download]
Abstract: This paper present result from an on-going research project on pressure tolerant power electronics where the power electronic components are enabled to operate in a pressurized dielectric environment. The driving force for the research is to provide new solutions for subsea high power converters that can get benefits by reduced weight and volume of pressure chambers, reduced number of electric power penetrators, obtain less complexity and more reliable cooling system, reduced costs and increased overall reliability. The components of most concern have been power semiconductors, power capacitors and IGBT gate drivers. Even though the work reported in this paper is still in progress, the basic investigations and experimental work so far indicates that reliable solutions for pressure tolerant power electronics has a high potential for success, when all power components and gate driver electronics are vacuumized and soaked in a proper dielectric fluid. This is valid for the individual components as well as for the complete circuits. Also the feedbacks from the components manufacturers are uplifting in that respect.

	Flatness based control of a fuel cell-supercapacitor multi source/multi load hybrid system By Alireza PAYMAN, serge PIERFEDERICI, farid MEIBODY-TABAR, bernard DAVAT	[View] [Download]
Abstract: This paper presents the flatness based control of a multi-source/multi-load electrical hybrid system (EHS) composed of a fuel cell and a supercapacitor-bank (SCB) as the main and auxiliary source, respectively. The main and auxiliary sources are connected to a DC link which has a floating voltage. This DC-power source supplies three independent 5V, 12V and 24V loads which are connected to the DC link through different buck converters. A flatness based method is used in this paper to control the hybrid system. For this purpose, the electrostatic energy stored on the DC link and also output capacitors are considered as the flat outputs of the system. Then, different reference trajectories are planned on these outputs and they are forced to track their references. The dynamics of fuel cell is limited by controlling the DC link voltage variation which is carried out by putting a filter on the reference of DC link trajectory. The proposed method does not contain commutation algorithm whereas the different operating modes exist. The implementation results are presented to validate operation of the proposed method in the multi source/multi load hybrid system.

	Hybrid Drive System of an Industrial Truck Using a Three-Phase DC-DC Converter Feeding Ultra-Capacitors By Christian RUDOLPH	[View] [Download]
Abstract: The diesel-electric drive system of an industrial truck is extended with an energy storage subsystem utilizing ultra-capacitors thus establishing a reliable technical solution with a great energy saving potential. A bidirectional three-phase DC-DC converter is proposed to charge the ultra-capacitors during the regenerative braking of the electric drive and to discharge them when peak power is demanded. The developed DC-DC converter uses three-phase coupled inductors for filtering its phase and output currents. The presented current-control for the DC-DC converter is both effective and easy to implement. Practical results show that the DC-DC converter operates reliably in the laboratory as well as in the hybrid drive system of industrial trucks. Depending on the field of application for the industrial truck, total energy savings of ten to twenty percent are possible.

	Model-based sensorless control of a SPM Synchronous Motor Drive for a Hybrid Catamaran By Silverio BOLOGNANI	[View] [Download]
Abstract: The paper deals with a sensorless control of a Permanent Magnet synchronous motor drive for a hybrid electric catamaran. A Surfaceâ€“mounted Permanent Magnet motor has been chosen and a distinctive sensorless control of this machine is deeply described. Control performance is validated by simulation and experimental results. Start-up mode, reversal of speed and synchronization lost occurrence will be specifically treated.

	Modeling and Simulation of Marine On-board Electrical Network By Pedro Neiva KVIESKA, Mourad AÃT-AHMED, Guy LEBRET, Gang YAO	[View] [Download]
Abstract: This paper presents detailed models and simulators for an electrical on-board marine network. A one machine network is considered, and loads are described, initially, as equivalent RL circuits based on active and reactive powers, which results in a 5th order dynamic system. Then a more refined model with capacitances is proposed, which results in a 9th order dynamic system. This model represents the network in a simple and yet realistic way. The behavior of this system for different load situations leads to a load classification that is briefly discussed. To perfectly know the conditions of the load commutations that are being analyzed, electrical simulators were developed in the Matlab/Simulink environment. Both simulators, for each one of the load models are here described. The RL simulator presents a very good performance, and the RLC a very large range of adaptability.

	Novel Voltage Balancer forElectric Double Layer Capacitor by Using CW circuit By Keiju MATSUI, Hiroto SHIMADA, Masaru HASEGAWA, Takayoshi SUZUKI	[View] [Download]
Abstract: EDLCs (Electric Double Layer Capacitors) offer high energy density and long life span, so various applications may be anticipated in the realm of energy storage devices, such as those used in electric vehicles or electric power stabilisation in power systems, etc. However, since the voltage limit is low of the devices, it is necessary to connect them in series or parallel. In addition, it is required that they be used in the region of their critical voltage limit or capacity limit. In order to apply them efficiently, the devices should be use with balanced voltage. Firstly, the authors discuss a conventional method, for example using a forward converter, etc. In a second approach, a novel voltage balancer is presented, employing a CW(Cockcroft-Walton) circuit. Characteristics of proposed circuit are analized and discussed.

	Power Electronics Interface for an Hybrid PEMFC Generating System with Fault Management Strategies for Transportation By Alexandre DE BERNARDINIS, Denis CANDUSSO, Fabien HAREL, GÃ©rard COQUERY	[View] [Download]
Abstract: This paper presents a fault tolerant power electronics interface used in an hybrid PEM Fuel Cell generating system for transportation. A battery plays the role of an energy buffer on the DC link. Anti-parallel bypass diodes are used to isolate a defective fuel cell module. An interleaved boost converter with backup strategies realizes the electrical interface. The diode derivation circuit and the electrical converter can ensure uninterrupted power delivery and fault management. Simulations with degraded working modes for the fuel cell and power converter are presented and the diode bypass function is experimentally validated on a 20-cell 500W PEM fuel cell stack.

	Rapid Modelling and Design of Variable Speed Permanent Magnet Generators for Maritime Applications By Juan Marcelo GUTIERREZ ALCARAZ, Nada AL-FARTUSI, Henk POLINDER, J.A. FERREIRA	[View] [Download]
Abstract: Electrical power generation plays an important role in maritime vessels. This power is usually provided by a multi-component system where the generation begins with the rotational movement of a prime mover, usually and Internal Combustion Engine, an electric generator and an assortment of power electronic components to process and regulate electrical energy. Due to the requirements of the application, i.e. power-on-demand to reduce fuel consumption and increase user comfort, all components need to be adapted to perform efficiently within a wide range of output power levels. For such a purpose a Variable Speed Permanent Magnet Generator (VSPMG) is presented as a solution that fulfills most of the requirements of the power generation stage. However, the design of such of generator is a long process where multiple variables intervene. The following paper deals with a rapid modelling and design tool that helps evaluate a VSPMG with concentrated windings in a quick, and relatively accurate, manner. This tool can be used to obtain a first draft design that can be perfected after further analysis. Analytical equations and experimental data are presented for validation. A simplified thermal model is also presented with the corresponding experimental counterpart. Finally, conclusions are given and next steps are suggested.

	Some Considerations Concerning the Distribution of Electrical Energy in a Low Voltage System By Petre-Marian NICOLAE, Lucian MANDACHE, Ileana-Diana NICOLAE, Ioana-Gabriela SIRBU	[View] [Download]
Abstract: One presents the main disturbances sources from the distribution substations used for urban electric transportation systems: transformers from substations; three-phase supplying line; converters from substations; contact line and path rails. Using a quality analyzer, numerical recordings are obtained representing the waveforms of voltages and currents in a substation for the transformation medium to low voltage. The recorded data are transferred to a PC and processed, based on an original decomposition algorithm that implements the Fast Fourier Transform (FFT). The study case refers to a global consumption of a substation with an approximate active power of 590 kW and reactive power 65 kVAr. Harmonic decompositions of the recorded voltages and currents are made. One computes a series of quantities characteristic to the analyzed distorting regime (RMS values, total harmonic distortion for the phase voltages and phase currents, a.o.). The waveforms are afterward recomposed revealing that the computation error introduced by the decomposition algorithm is very small. The phases (re)active powers and total powers are determined. Interpretations of the determined values are provided. The analysis reveals the necessity to create a dedicated data acquisition system for each transformation substation in order to provide a complete monitoring system. Also should be useful the development of some real time recording and processing systems to realize a compensation efficient both from the distorting regime point of view and respectively from the compensation along the fundamental harmonic.

	THE ENERGY STORAGE SYSTEM FOR PUBLIC TRANSPORT By Lubos STREIT, Pavel DRABEK	[View] [Download]
Abstract: This paper presents research motivated by industrial demand for energy storage system for city transport vehicles. Our city transport has problems with stability of the trolley line voltage at the several places in the city a therefore this research has been started. Energy storage system with supercapacitors is one solution. The kinetic energy is accumulated into the supercapacitor during vehicle braking. This energy can be used to accelerating again. It is important to save the energy in the vehicles, which accelerate very often (we can think about stabile or mobile version).

	The Stability Analysis of AC-DC Systems Including Actuator Dynamics for Aircraft Power Systems By KONGPAN AREERAK, Serhiy BOZHKO, Greg ASHER, LILIANA DE LILLO, ALAN WATSON, Tao WU, Dave THOMAS	[View] [Download]
Abstract: This paper presents the small-signal stability analysis of AC-DC power system taking into account dynamics of electromechanical actuator (EMA). A dq modelling method is employed to predict unstable operation caused by possible variations in operating points and/or system parameters. The obtained theoretical results are supported by intensive simulations and verified experimentally.

	Weight and Efficiency Optimization Strategy of an interleaved DC-DC Converter for a Solar Aircraft By Yannick LOUVRIER, Philippe BARRADE, Alfred RUFER	[View] [Download]
Abstract: Today, energy saving is one of the main objectives for engineers. In the case of mobile applications, energy can be saved by two different ways. First, decreasing the total masse of the system, and second, increasing the efficiency of the overall system.This paper presents an optimization strategy to design an interleaved DC/DC converter in order to find the best compromise between efficiency, weight and current inductor ripple. The strategy of this method also lends itself well to find the right split power level that must by selected to obtain the best efficiency and weight power density of a given application.