EPE Association: EPE 2011 - DS3f: Topic 10: Synchronous, Permanent Magnet Synchronous and Brushless DC Motor

EPE 2011 - DS3f: Topic 10: Synchronous, Permanent Magnet Synchronous and Brushless DC Motor
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2011 ECCE Europe - Conference > EPE 2011 - Topic 10: Electrical Machines > EPE 2011 - DS3f: Topic 10: Synchronous, Permanent Magnet Synchronous and Brushless DC Motor

   [return to parent folder]

   A Novel Switched Reluctance Machine with Windings and Permanent Magnets in the Stator Yoke
By Yu HASEGAWA, Kenji NAKAMURA, Osamu ICHINOKURA [View]
[Download]

Abstract: This paper presents a novel switched reluctance (SR) machine which has both windings and permanent magnets in the stator yoke. Characteristics of the proposed SR machine operating as a motor and generator are estimated by a finite element method, and compare with that of conventional reluctance machines.

   Basic Examination of Eddy Current Estimation based on Reluctance Network Analysis
By Yukihiro YOSHIDA, Kenji NAKAMURA, Osamu ICHINOKURA [View]
[Download]

Abstract: This paper presents a method for calculating eddy current loss based on reluctance network analysis (RNA) considering the magnetic reaction field caused by the eddy current by using magnetic inductance. First, an electric network model for calculating eddy current is indicated. Next, RNA model considering the magnetic reaction field is presented. The validity of the proposed model is proved by comparing with the finite element Analysis (FEA) and experiment.

   Comparison of an Active Stator and a 3-phase synchronous machine
By Neamat T. IRENJI [View]
[Download]

Abstract: The electromagnetic developed torque of a conventional three-phase machine is compared with that of the same machine rearranged as an Active Stator machine, a new multiphase machine concept developed by Converteam UK Ltd. The comparison is made by using analytical methods and Finite Element solutions. Relations describing the average developed torque are derived for both three phase and AS machines.For the same physical dimensions the AS machine produces higher developed torque, offering an economical alternative to conventional machines especially in applications with very low to medium speeds such as the wind energy sector.

   Design and Control of a Single Stator Dual PM Rotors Axial Synchronous Machine for Hybrid Electric Vehicles
By Lucian Nicolae TUTELEA, Ion BOLDEA, Sorin Ioan DEACONU, Fabrizio MARIGNETTI, Gabriel Nicolae POPA [View]
[Download]

Abstract: In this paper is presenting the preliminary designing and control of a synchronous machine with axial airgap single stator dual-rotor with permanent surface magnets and different pole pairs number, destined for hybrid electric vehicles (HEV) applications. For machine’s designing was used the equivalent magnetic circuits method that takes into account the saturation and dispersion of the magnetic field.The control model is developed for a single inverter that produces three phase output voltage with two frequencies components; the torque current for each rotor is controlled through the stator current that passes the two serial windings.The machine, coupled with the thermal engine (ICE), can operate as starter for short time at start-up and as generator, when the rotational speed is established by the thermal engine’s regulator.The other machine can operate as motor in wide speed range (both inferior and superior to the generator’s), but also in generator regime with power recovery at braking.

   Design of integrated electro-hydraulic power unit for hybrid mobile working machines
By Pavel PONOMAREV, Maria POLIKARPOVA, Olli HEINIKAINEN, Juha PYRHÖNEN [View]
[Download]

Abstract: A high power density integrated non-overlapping concentrated tooth winding synchronous machine with embedded permanent magnets for a hydraulic motor-pump is designed. Direct liquid cooling with the working fluid itself is implemented. Aspects of immersing the motor into hydraulic oil for cooling purposes are discussed. FEM modelling of PM eddy-current losses and static temperature evaluation are performed.

   Detection of Inter-Turns Short Circuits in Permanent Magnet Synchronous Motors Operating under Transient Conditions by means of the Zero Sequence Voltage
By Julio URRESTY, Jordi-Roger RIBA, Harold SAAVEDRA, Jose Luis ROMERAL [View]
[Download]

Abstract: This work proposes the zero sequence voltage component (ZSVC) of the stator three-phase voltages as a method for detecting winding inter-turns short circuits in permanent magnet synchronous motors PMSM operating under transient conditions. Additionally it proves the linear relationship between the ZSVC and speed, which is effectively used as a fault severity index. The acquired ZSVC temporal signal is processed by means of the Hilbert-Huang transform (HHT).Experimental results presented in this work show the advantages of the method to provide helpful data for online diagnosis of stator winding inter-turn faults.

   Dynamic Simulation of Planetary type Magnetic Gear based on Reluctance Network Analysis
By Michinari FUKUOKA, Kenji NAKAMURA, Osamu ICHINOKURA [View]
[Download]

Abstract: Magnetic gears have attractive features such as low acoustic noise and maintenance-free operation in comparison with conventional mechanical gears. Planetary type magnetic gears, especially, have higher transmission torque than the other types. Therefore, the magnetic gears are expected to be put into practical use. This paper presents a method for dynamic simulation of the planetary type magnetic gears based on reluctance network analysis (RNA). The RNA has several features including a simple analytical model, high calculation accuracy, and ease of coupled simulation with rotational motion of rotors.

   Evaluation of the Machine Non-Linearities as a Aid to Develop Self-Commissioning in Sensorless Drives
By Jesus ARELLANO-PADILLA, Mark SUMNER, Chris GERADA, Gary BUCKLEY [View]
[Download]

Abstract: This paper investigates the minimum requirements to implement compensation schemes for saliency based sensorless control schemes that will work successfully irrespective of the method or machine type. The paper focuses on analyzing the saliency disturbance components due to the machine only, by simulating a machine with a FEM model, and coupling this to a simulation of a full sensorless control which uses ideal power electronic components. The initial results show common saliency harmonics which can therefore simplify the setting up of the filters used to clean up position estimates in sensorless drives.

   Investigation into Commutation Torque Ripple Reduction in a BDCM Drive Using Various Combined PWM-Square-PWM Control Strategies
By Houcine ZEROUG, Nadia TADRIST, Boussad BOUKAIS, Houria SAHRAOUI [View]
[Download]

Abstract: In this paper, commutation torque ripple in a brushless dc motor is examined using simple fixed frequency PWM combined with square wave control strategies. These were easily derived from true Hall Effect sensor signals through decoding. The performances of the drive were examined from Matlab based simulation model using these techniques. It shows that the PWM-ON/ON-PWM presents better commutation torque ripple compensation over a large operating speed range. But H\_PWM/L\_PWM present better time response, a compromise has to be made between these strategies. An experimental testing bed was built to confirm the effectiveness of the approach used.

   Magnet eddy current loss calculation method for segmentation analysis on Permanent Magnet Machines
By Patxi MADINA, Javier POZA, Gaizka UGALDE, Gaizka ALMANDOZ [View]
[Download]

Abstract: Eddy current losses generated in the rotor of permanent magnet machines may lead to an excessive magnet heating. This can cause the magnets to get fully demagnetized so it is very important to analyze the losses on them. In high power application usually it is necessary to design solutions to reduce eddy current losses. The most common technique is the magnet segmentation. Analytical calculation of magnet eddy current losses may give some inaccuracies on the results and FEM analysis may be too time-consuming in some design steps. A new method that combines FEM and numerical calculations to evaluate the losses for different magnet segmentation is presented in this paper.

   Modelling of Electrically Excited Synchronous Machine (EESM) considering nonlinear material characteristics and multiple saliencies
By Markus SEILMEIER [View]
[Download]

Abstract: Sophisticated control techniques for electrically excited synchronous machines need precise, but easymodels. Non-ideal characteristics may appear, if the machine shows multiple geometric and/or saturationinduced saliencies. In contrast to the conventional modelling approach, a novel stator-oriented magneticcircuit approach is used to deduce a nonlinear machine model with time-variant parameters, which makesit possible to account for multiple geometric and saturation induced saliencies systematically. Using thismethod one can find systematic conditions whether the cross saturation effect can occur. Moreover thenew modeling technique leads to new insights for the interpretation of the resulting differential equationsin the field oriented coordinates. One finds that both the differential and absolute inductances are relevantfor torque generation in the machine.

   Multiphysic optimal design of an inverter fed PMSM and choice of the switching frequency
By Benjamin DAGUSE, Xavier JANNOT, Christophe LEDOUX, Pierre LEFRANC, Jean-Claude VANNIER [View]
[Download]

Abstract: The aim of this paper is to perform an optimal design of a surface mounted PMSM, dedicated to an embedded application, based on a multiphysic modelling and using a genetic algorithm. Finally, a quantitative criterion, regarding the torque ripple, is introduced to choose the switching frequency of the power electronic supply.

   Parameter Optimization Study and Performance Analysis of 6S-8P Permanent Magnet Flux Switching Machine with Field Excitation for High Speed Hybrid Electric Vehi
By Erwan SULAIMAN, Takashi KOSAKA, Nobuyuki MATSUI [View]
[Download]

Abstract: Over the past decade, many automotive companies have been commercializing HEVs. Most of them employ interior permanent magnet synchronous machine (IPMSM) using rare-earth magnet as their main traction drives from viewpoints of high torque and power density and high efficiency over most of operating torque-speed ranges. However, since all permanent magnets (PMs) are located on rotor part, a design approach to ensure mechanical strength of the rotor depends on rib thickness and number of bridges between PMs. The increase in the number of bridges improves the mechanical strength, but reduces the maximum torque of the machine due to an increase in leakage flux of PM. To overcome this problem, 6S-8P permanent magnet flux switching machine with additional field excitation coil is presented. The proposed machine has all active parts on the stator body and a rugged rotor structure suitable for high speed operation. Some design parameter refinements are conducted to this machine in order to elevate maximum torque and maximum power densities. As a result, it is shown that the proposed machine after the design refinements becomes a good candidate for target HEV drive applications.

   Performance Analysis and Comparison of Three Interior Permanent Magnet Synchronous Motor with High Homopolar Inductance for Electric Vehicle Applications
By Hussein DOGAN, Albert FOGGIA, Frédéric WURTZ, Lauric GARBUIO [View]
[Download]

Abstract: This paper presents a comparison of different permanent magnets synchronous motors (PMSM) having a high homopolar or zero-sequence inductance. The high value of zero-sequence inductance is particularly a necessity for certain applications in which the winding coupling is not in Wye connection. Thereby, the homopolar currents which are sources of losses are reduced and minimized. In this study, we investigate three topologies of PMSM according to the specifications of an electric vehicle (EV) with severe constraints and a maximum rotation speed of 12, 000 rpm. Those fractional-slots machines are the 3-phase 12 slots / 8 rotor poles (12/8), the 12/10 and the 18/10. Then, the goal is to compare and evaluate the topologies firstly with a fast and coarse approach and then with finite element analysis (FEA) to finally determine which is the most suitable for the application.

   Principle and Basic Characteristics of a Hybrid Variable Magnetic-Force Motor
By Kazuto SAKAI, Satoru KURAMOCHI, Hisanori HASHIMOTO [View]
[Download]

Abstract: Reduction in power consumed by motors is required for energy saving in electrical appliances and electric vehicles. The motors used in such appliances and vehicles operate at variable speeds. For reducing energy consumption of electrical appliances, the flux-weakening current that depresses the voltage at high speed leads to significant copper and core losses. Therefore, we have developed a new technique for controlling the magnetic force of a permanent magnet on the basis of the load or speed of the motor. In this paper, we propose a novel motor that can vary the magnetic flux of permanent magnets and clarify the principle and basic characteristics of the motor. Our motor has a permanent magnet magnetized by magnetizing coils of the stator. The results show that the motor can vary magnetic flux linkage from 37\% to 100\% and produce high torque. In addition, when positive field current flow in the magnetizing coils as a field coil, maximum torque increases by 25 \%. Also, the induced voltage can decrease to 0 V by negative field current. The results of our analysis prove that our novel motor can vary the flux of a permanent magnet on the load and can be used in a variable-speed drive with high performance.

   Sensorless Control at High Starting Torque of a 4000 Nm Traction Drive With Permanent Magnet Synchronous Machine
By Florian DEMMELMAYR [View]
[Download]

Abstract: This paper presents numerical torque simulations and sensorless control of a permanent magnet synchronous machine (PMSM). The machine was developed for a wheel-hub traction drive with a maximumtorque of 4000 Nm. The Indirect Flux detection by Online Reactance Measurement (INFORM) methodprovides control at standstill and low speed without a rotor position sensor. A back electromotive force(EMF) model handles the operation at higher speed. The structure of the control and the load behaviourof INFORM are shown. The torque characteristic is calculated by numerical simulation and comparedwith recorded values. An additional curve depicts the influence of the INFORM test signals on machinetorque.

   The Influence of Impact Load on Torsional Dynamics of Generator Units
By Marija MIROSEVIC, Zlatko MALJKOVIC, Mateo MILKOVIC [View]
[Download]

Abstract: The paper analyses the dynamics of generator-units, as well as induction motors during impact loads. Mathematical model of integral motor drives consisting of: diesel engine, synchronous generator and motor drives has been developed. The aim is to compare torsional dynamics during direct-on-line starting of induction motors with changing loads.

   Thermal analysis of permanent-magnet synchronous reluctance machines
By Shafigh NATEGH, Oskar WALLMARK, Mats LEKSELL [View]
[Download]

Abstract: This paper presents a thermal analysis of permanent-magnet synchronous reluctance machines (PMSRM). Particular focus is put on the rotor and two lumped parameter (LP) thermal models of the rotorare implemented and evaluated. The results of the two LP thermal models are compared to thermal simulations using the finite element method (FEM). Induced eddy current losses in the permanent magnets are computed using three-dimensional (3D) FEM computations whereas the losses in the electrical steel are obtained using a 2D FEM model. Based on type of cooling system, two cases are evaluated and the agreement between the two LP thermal simulations and the thermal FEM simulation is generally good but particular differences are highlighted. In the first case, the water cooling system manages to effectively handle the dominating copper losses which results in only a minor temperature difference between the shaft and the inner part of the stator teeth. In the second case, it is assumed that there is a significant temperature difference between the rotor shaft and the stator.

   Validation of Non-linear Dynamic FEM Model for Design of PM Machines with Concentrated Windings in Ship Application
By Hung VU XUAN, Ani SAMUEL, Domenico LAHAYE, Henk POLINDER, Ferreira BRAM [View]
[Download]

Abstract: The machine under study is a surface-mounted outer rotor permanent magnet (PM) synchronous machine with concentrated windings, which is integrated in a flywheel of a diesel engine. The main objective of this work is to build an accurate nonlinear transient finite element method (FEM) model coupling to circuit model and validate this experimentally. The FEM model is made by scripts, so it is very convenient to change design parameters of PM machine. This will help in design optimization of PM machines. A sample PM machine is investigated for validating no-load voltage, load voltage, electric current, electromagnetic torque, short circuit current and reactance of FEM model. Comparison of simulation and experimental results shows very good agreement with error margin smaller than 3\%. Results show that the end effects of a PM machine with concentrated windings having large number of teeth and poles can be neglected, even when its diameter is larger than its length. Analysis of results during three-phase short circuit shows that armature current during short circuit is limited strongly by armature reaction in the d-axis direction, even though the winding resistance is much smaller than the reactance. It can be shown that a PM machine designed with reasonable reactance can avoid demagnetization due to three-phase short circuit.

EPE 2011 - DS3f: Topic 10: Synchronous, Permanent Magnet Synchronous and Brushless DC Motor
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2011 ECCE Europe - Conference > EPE 2011 - Topic 10: Electrical Machines > EPE 2011 - DS3f: Topic 10: Synchronous, Permanent Magnet Synchronous and Brushless DC Motor
	[return to parent folder]

	A Novel Switched Reluctance Machine with Windings and Permanent Magnets in the Stator Yoke By Yu HASEGAWA, Kenji NAKAMURA, Osamu ICHINOKURA	[View] [Download]
Abstract: This paper presents a novel switched reluctance (SR) machine which has both windings and permanent magnets in the stator yoke. Characteristics of the proposed SR machine operating as a motor and generator are estimated by a finite element method, and compare with that of conventional reluctance machines.

	Basic Examination of Eddy Current Estimation based on Reluctance Network Analysis By Yukihiro YOSHIDA, Kenji NAKAMURA, Osamu ICHINOKURA	[View] [Download]
Abstract: This paper presents a method for calculating eddy current loss based on reluctance network analysis (RNA) considering the magnetic reaction field caused by the eddy current by using magnetic inductance. First, an electric network model for calculating eddy current is indicated. Next, RNA model considering the magnetic reaction field is presented. The validity of the proposed model is proved by comparing with the finite element Analysis (FEA) and experiment.

	Comparison of an Active Stator and a 3-phase synchronous machine By Neamat T. IRENJI	[View] [Download]
Abstract: The electromagnetic developed torque of a conventional three-phase machine is compared with that of the same machine rearranged as an Active Stator machine, a new multiphase machine concept developed by Converteam UK Ltd. The comparison is made by using analytical methods and Finite Element solutions. Relations describing the average developed torque are derived for both three phase and AS machines.For the same physical dimensions the AS machine produces higher developed torque, offering an economical alternative to conventional machines especially in applications with very low to medium speeds such as the wind energy sector.

	Design and Control of a Single Stator Dual PM Rotors Axial Synchronous Machine for Hybrid Electric Vehicles By Lucian Nicolae TUTELEA, Ion BOLDEA, Sorin Ioan DEACONU, Fabrizio MARIGNETTI, Gabriel Nicolae POPA	[View] [Download]
Abstract: In this paper is presenting the preliminary designing and control of a synchronous machine with axial airgap single stator dual-rotor with permanent surface magnets and different pole pairs number, destined for hybrid electric vehicles (HEV) applications. For machine’s designing was used the equivalent magnetic circuits method that takes into account the saturation and dispersion of the magnetic field.The control model is developed for a single inverter that produces three phase output voltage with two frequencies components; the torque current for each rotor is controlled through the stator current that passes the two serial windings.The machine, coupled with the thermal engine (ICE), can operate as starter for short time at start-up and as generator, when the rotational speed is established by the thermal engine’s regulator.The other machine can operate as motor in wide speed range (both inferior and superior to the generator’s), but also in generator regime with power recovery at braking.

	Design of integrated electro-hydraulic power unit for hybrid mobile working machines By Pavel PONOMAREV, Maria POLIKARPOVA, Olli HEINIKAINEN, Juha PYRHÖNEN	[View] [Download]
Abstract: A high power density integrated non-overlapping concentrated tooth winding synchronous machine with embedded permanent magnets for a hydraulic motor-pump is designed. Direct liquid cooling with the working fluid itself is implemented. Aspects of immersing the motor into hydraulic oil for cooling purposes are discussed. FEM modelling of PM eddy-current losses and static temperature evaluation are performed.

	Detection of Inter-Turns Short Circuits in Permanent Magnet Synchronous Motors Operating under Transient Conditions by means of the Zero Sequence Voltage By Julio URRESTY, Jordi-Roger RIBA, Harold SAAVEDRA, Jose Luis ROMERAL	[View] [Download]
Abstract: This work proposes the zero sequence voltage component (ZSVC) of the stator three-phase voltages as a method for detecting winding inter-turns short circuits in permanent magnet synchronous motors PMSM operating under transient conditions. Additionally it proves the linear relationship between the ZSVC and speed, which is effectively used as a fault severity index. The acquired ZSVC temporal signal is processed by means of the Hilbert-Huang transform (HHT).Experimental results presented in this work show the advantages of the method to provide helpful data for online diagnosis of stator winding inter-turn faults.

	Dynamic Simulation of Planetary type Magnetic Gear based on Reluctance Network Analysis By Michinari FUKUOKA, Kenji NAKAMURA, Osamu ICHINOKURA	[View] [Download]
Abstract: Magnetic gears have attractive features such as low acoustic noise and maintenance-free operation in comparison with conventional mechanical gears. Planetary type magnetic gears, especially, have higher transmission torque than the other types. Therefore, the magnetic gears are expected to be put into practical use. This paper presents a method for dynamic simulation of the planetary type magnetic gears based on reluctance network analysis (RNA). The RNA has several features including a simple analytical model, high calculation accuracy, and ease of coupled simulation with rotational motion of rotors.

	Evaluation of the Machine Non-Linearities as a Aid to Develop Self-Commissioning in Sensorless Drives By Jesus ARELLANO-PADILLA, Mark SUMNER, Chris GERADA, Gary BUCKLEY	[View] [Download]
Abstract: This paper investigates the minimum requirements to implement compensation schemes for saliency based sensorless control schemes that will work successfully irrespective of the method or machine type. The paper focuses on analyzing the saliency disturbance components due to the machine only, by simulating a machine with a FEM model, and coupling this to a simulation of a full sensorless control which uses ideal power electronic components. The initial results show common saliency harmonics which can therefore simplify the setting up of the filters used to clean up position estimates in sensorless drives.

	Investigation into Commutation Torque Ripple Reduction in a BDCM Drive Using Various Combined PWM-Square-PWM Control Strategies By Houcine ZEROUG, Nadia TADRIST, Boussad BOUKAIS, Houria SAHRAOUI	[View] [Download]
Abstract: In this paper, commutation torque ripple in a brushless dc motor is examined using simple fixed frequency PWM combined with square wave control strategies. These were easily derived from true Hall Effect sensor signals through decoding. The performances of the drive were examined from Matlab based simulation model using these techniques. It shows that the PWM-ON/ON-PWM presents better commutation torque ripple compensation over a large operating speed range. But H\_PWM/L\_PWM present better time response, a compromise has to be made between these strategies. An experimental testing bed was built to confirm the effectiveness of the approach used.

	Magnet eddy current loss calculation method for segmentation analysis on Permanent Magnet Machines By Patxi MADINA, Javier POZA, Gaizka UGALDE, Gaizka ALMANDOZ	[View] [Download]
Abstract: Eddy current losses generated in the rotor of permanent magnet machines may lead to an excessive magnet heating. This can cause the magnets to get fully demagnetized so it is very important to analyze the losses on them. In high power application usually it is necessary to design solutions to reduce eddy current losses. The most common technique is the magnet segmentation. Analytical calculation of magnet eddy current losses may give some inaccuracies on the results and FEM analysis may be too time-consuming in some design steps. A new method that combines FEM and numerical calculations to evaluate the losses for different magnet segmentation is presented in this paper.

	Modelling of Electrically Excited Synchronous Machine (EESM) considering nonlinear material characteristics and multiple saliencies By Markus SEILMEIER	[View] [Download]
Abstract: Sophisticated control techniques for electrically excited synchronous machines need precise, but easymodels. Non-ideal characteristics may appear, if the machine shows multiple geometric and/or saturationinduced saliencies. In contrast to the conventional modelling approach, a novel stator-oriented magneticcircuit approach is used to deduce a nonlinear machine model with time-variant parameters, which makesit possible to account for multiple geometric and saturation induced saliencies systematically. Using thismethod one can find systematic conditions whether the cross saturation effect can occur. Moreover thenew modeling technique leads to new insights for the interpretation of the resulting differential equationsin the field oriented coordinates. One finds that both the differential and absolute inductances are relevantfor torque generation in the machine.

	Multiphysic optimal design of an inverter fed PMSM and choice of the switching frequency By Benjamin DAGUSE, Xavier JANNOT, Christophe LEDOUX, Pierre LEFRANC, Jean-Claude VANNIER	[View] [Download]
Abstract: The aim of this paper is to perform an optimal design of a surface mounted PMSM, dedicated to an embedded application, based on a multiphysic modelling and using a genetic algorithm. Finally, a quantitative criterion, regarding the torque ripple, is introduced to choose the switching frequency of the power electronic supply.

	Parameter Optimization Study and Performance Analysis of 6S-8P Permanent Magnet Flux Switching Machine with Field Excitation for High Speed Hybrid Electric Vehi By Erwan SULAIMAN, Takashi KOSAKA, Nobuyuki MATSUI	[View] [Download]
Abstract: Over the past decade, many automotive companies have been commercializing HEVs. Most of them employ interior permanent magnet synchronous machine (IPMSM) using rare-earth magnet as their main traction drives from viewpoints of high torque and power density and high efficiency over most of operating torque-speed ranges. However, since all permanent magnets (PMs) are located on rotor part, a design approach to ensure mechanical strength of the rotor depends on rib thickness and number of bridges between PMs. The increase in the number of bridges improves the mechanical strength, but reduces the maximum torque of the machine due to an increase in leakage flux of PM. To overcome this problem, 6S-8P permanent magnet flux switching machine with additional field excitation coil is presented. The proposed machine has all active parts on the stator body and a rugged rotor structure suitable for high speed operation. Some design parameter refinements are conducted to this machine in order to elevate maximum torque and maximum power densities. As a result, it is shown that the proposed machine after the design refinements becomes a good candidate for target HEV drive applications.

	Performance Analysis and Comparison of Three Interior Permanent Magnet Synchronous Motor with High Homopolar Inductance for Electric Vehicle Applications By Hussein DOGAN, Albert FOGGIA, Frédéric WURTZ, Lauric GARBUIO	[View] [Download]
Abstract: This paper presents a comparison of different permanent magnets synchronous motors (PMSM) having a high homopolar or zero-sequence inductance. The high value of zero-sequence inductance is particularly a necessity for certain applications in which the winding coupling is not in Wye connection. Thereby, the homopolar currents which are sources of losses are reduced and minimized. In this study, we investigate three topologies of PMSM according to the specifications of an electric vehicle (EV) with severe constraints and a maximum rotation speed of 12, 000 rpm. Those fractional-slots machines are the 3-phase 12 slots / 8 rotor poles (12/8), the 12/10 and the 18/10. Then, the goal is to compare and evaluate the topologies firstly with a fast and coarse approach and then with finite element analysis (FEA) to finally determine which is the most suitable for the application.

	Principle and Basic Characteristics of a Hybrid Variable Magnetic-Force Motor By Kazuto SAKAI, Satoru KURAMOCHI, Hisanori HASHIMOTO	[View] [Download]
Abstract: Reduction in power consumed by motors is required for energy saving in electrical appliances and electric vehicles. The motors used in such appliances and vehicles operate at variable speeds. For reducing energy consumption of electrical appliances, the flux-weakening current that depresses the voltage at high speed leads to significant copper and core losses. Therefore, we have developed a new technique for controlling the magnetic force of a permanent magnet on the basis of the load or speed of the motor. In this paper, we propose a novel motor that can vary the magnetic flux of permanent magnets and clarify the principle and basic characteristics of the motor. Our motor has a permanent magnet magnetized by magnetizing coils of the stator. The results show that the motor can vary magnetic flux linkage from 37\% to 100\% and produce high torque. In addition, when positive field current flow in the magnetizing coils as a field coil, maximum torque increases by 25 \%. Also, the induced voltage can decrease to 0 V by negative field current. The results of our analysis prove that our novel motor can vary the flux of a permanent magnet on the load and can be used in a variable-speed drive with high performance.

	Sensorless Control at High Starting Torque of a 4000 Nm Traction Drive With Permanent Magnet Synchronous Machine By Florian DEMMELMAYR	[View] [Download]
Abstract: This paper presents numerical torque simulations and sensorless control of a permanent magnet synchronous machine (PMSM). The machine was developed for a wheel-hub traction drive with a maximumtorque of 4000 Nm. The Indirect Flux detection by Online Reactance Measurement (INFORM) methodprovides control at standstill and low speed without a rotor position sensor. A back electromotive force(EMF) model handles the operation at higher speed. The structure of the control and the load behaviourof INFORM are shown. The torque characteristic is calculated by numerical simulation and comparedwith recorded values. An additional curve depicts the influence of the INFORM test signals on machinetorque.

	The Influence of Impact Load on Torsional Dynamics of Generator Units By Marija MIROSEVIC, Zlatko MALJKOVIC, Mateo MILKOVIC	[View] [Download]
Abstract: The paper analyses the dynamics of generator-units, as well as induction motors during impact loads. Mathematical model of integral motor drives consisting of: diesel engine, synchronous generator and motor drives has been developed. The aim is to compare torsional dynamics during direct-on-line starting of induction motors with changing loads.

	Thermal analysis of permanent-magnet synchronous reluctance machines By Shafigh NATEGH, Oskar WALLMARK, Mats LEKSELL	[View] [Download]
Abstract: This paper presents a thermal analysis of permanent-magnet synchronous reluctance machines (PMSRM). Particular focus is put on the rotor and two lumped parameter (LP) thermal models of the rotorare implemented and evaluated. The results of the two LP thermal models are compared to thermal simulations using the finite element method (FEM). Induced eddy current losses in the permanent magnets are computed using three-dimensional (3D) FEM computations whereas the losses in the electrical steel are obtained using a 2D FEM model. Based on type of cooling system, two cases are evaluated and the agreement between the two LP thermal simulations and the thermal FEM simulation is generally good but particular differences are highlighted. In the first case, the water cooling system manages to effectively handle the dominating copper losses which results in only a minor temperature difference between the shaft and the inner part of the stator teeth. In the second case, it is assumed that there is a significant temperature difference between the rotor shaft and the stator.

	Validation of Non-linear Dynamic FEM Model for Design of PM Machines with Concentrated Windings in Ship Application By Hung VU XUAN, Ani SAMUEL, Domenico LAHAYE, Henk POLINDER, Ferreira BRAM	[View] [Download]
Abstract: The machine under study is a surface-mounted outer rotor permanent magnet (PM) synchronous machine with concentrated windings, which is integrated in a flywheel of a diesel engine. The main objective of this work is to build an accurate nonlinear transient finite element method (FEM) model coupling to circuit model and validate this experimentally. The FEM model is made by scripts, so it is very convenient to change design parameters of PM machine. This will help in design optimization of PM machines. A sample PM machine is investigated for validating no-load voltage, load voltage, electric current, electromagnetic torque, short circuit current and reactance of FEM model. Comparison of simulation and experimental results shows very good agreement with error margin smaller than 3\%. Results show that the end effects of a PM machine with concentrated windings having large number of teeth and poles can be neglected, even when its diameter is larger than its length. Analysis of results during three-phase short circuit shows that armature current during short circuit is limited strongly by armature reaction in the d-axis direction, even though the winding resistance is much smaller than the reactance. It can be shown that a PM machine designed with reasonable reactance can avoid demagnetization due to three-phase short circuit.