EPE Association: EPE 2016 - DS1e: Electrical Machines

EPE 2016 - DS1e: Electrical Machines
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2016 ECCE Europe - Conference > EPE 2016 - Topic 04: Electrical Machines and Drive Systems > EPE 2016 - DS1e: Electrical Machines

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   An Improved Dynamic model for Simulation and Stability Analysis of Brushless Doubly Fed Machines
By Mohammad Naser HASHEMNIA [View]
[Download]

Abstract: This paper presents a dynamic model for brushless doubly fed machine including core loss. Using the space vector notation, the conventional equivalent circuit model of the machine is modified to take the core loss effect into account. The proposed method introduces resistances corresponding to stator/rotor core loss components designated to the power/control windings. This model can be used for enhanced time-domain simulations, design of high performance control strategies with core loss detuning effect compensation and also as a tool for stability analysis of the machine drive under different control methods. The dynamic model of a prototype machine is simulated with and without consideration of core loss, and the results are compared with finite element simulations to show the superiority of the proposed model to the conventional one.

   Construction of the FSPM machine and its measurement in comparison with modeled results
By Pavel SVETLIK [View]
[Download]

Abstract: This paper deals with construction of a prototype of a flux-switching permanent magnet machine (FSPM). This machine was manufactured on behalf of mathematical calculations and created models. These models are compared with measurement performed on the real machine and some conclusions about quality of manufactured machine are presented.

   Design Methodology of a High Speed Switched Reluctance Generator Drive for Aircrafts
By Marcos LAFOZ [View]
[Download]

Abstract: The paper proposes a high speed switched reluctance (SR) drive for aircraft applications, covering the demand of more electric aircrafts (MEA) and defending the particular benefits of this machine technology against others, such as permanent magnet synchronous generators. An appropriate topology of electrical machine and power converter for a high speed DC distribution grid is selected. Firstly, the electromagnetic design of the generator, by means of FEM, is described in detail, paying attention to the problem of the torque ripple and pointing out some solutions to improve it, based on an iterative optimisation of both stator and rotor geometries and phases activation and deactivation angles. Then, the design of power electronics is also analysed, obtaining the required modules and cooling system from a simulation model, using the maximum and average current levels as well as the duty cycles. The model has been developed from the generator electromagnetic design and integrates the control strategy, in charge of controlling the DC-link voltage. An iterative procedure using FEM analysis and the simulation model is also used to validate the thermal and mechanical behaviour of the system. Finally, the integration of the complete electric drive is discussed with the criteria of maintaining the system within the available room and keeping the temperature under the maximum limits. The application of aircraft equipment is specially demanding in terms of robustness, low maintenance, fault tolerance, high temperature and harsh environment, and those are the reasons why the SR generator is a reliable alternative.

   Dynamic load of induction machine due to rotor's eccentricity and bearing clearance
By Miroslav BYRTUS [View]
[Download]

Abstract: The most critical part of the induction machines which determines on their life time operation are rolling element bearings. To ensure reliable drive with an induction machine requires deep insight in electro-mechanical dynamics during its operation. The flexible multibody modeling technique enables the simulation of dynamic loads on all drive components. This paper focuses on complex dynamic modeling of machine's behavior in case of eccentrically placed rotor supported by nonlinear bearing with radial clearance. The life time of machine's bearing becomes very important issue of machine's maintenance and reliability and is markedly influenced by any unbalanced forces acting on the rotor. Only the complex electro-mechanical models of the rotor considering all unbalanced electrical and mechanical rotor forces can provide the very detailed information about the bearing load. The methodology of determination of such loading is applied to the 11 kW squirrel-cage induction machine.

   Effect of Micro-filler of Aluminium Oxide on the Mechanical, Electrical and Thermal Properties of Electrical Insulation Systems
By Tetjana TOMASKOVA [View]
[Download]

Abstract: Polymers are the preferred materials for use in electrical applications and for power electronics due to their simple of production, light weight and low cost. However, polymers have relatively low thermal conductivity. This paper deals with preparation of epoxy composites with content of micro-filler of aluminum oxide (Al2O3) with high thermal conductivity. Using specific fillers can improve performance parameters of electrical equipment and their thermal, electrical, mechanical properties without the design changes. When it found electrical insulating systems with higher value of thermal conductivity thus it would be possible to increase utilization of rotating machine, alternatively encumber of rotating machine of higher values of current, reduce the size and change the price of electric rotating machines.

   Electromagnetic Calculation of a Wound-Rotor Brushless Doubly-Fed Machine
By Fei XIONG [View]
[Download]

Abstract: To quickly and accurately calculate steady-state performance of wound-rotor BDFM, this paper presents an electromagnetic calculation method. A 100 kW wound-rotor BDFM is used as an example to verify the quickness and accuracy of the analytical method by the comparison of the calculation data, two-dimensional (2D) FEM simulation results and experimental data.

   Expanding the Operating Range of Permanent Magnet Synchronous Motors by Using the Optimum Number of Phases
By Miriam BOXRIKER [View]
[Download]

Abstract: A holistic approach to determine the optimum number of phases m of an m-phase motor in combinationwith an m-leg inverter for electric vehicle applications is presented. The optimum offers a significantimprovement of the torque and power by approximately 9.6\% over the whole operating range in comparisonto a 3-phase motor and therefore enhances the power and torque density without expanding thedesign parameters of the machine.

   MMF Harmonic Analysis of Polyphase Windings based on the Closed-form Analytical Equation
By Xiang REN [View]
[Download]

Abstract: The several new winding configurations, such as fractional slot concentrated winding andconcentrated winding with two slot pitches, have been attracted lots of attentions due to their inherentadvantages such as short ending winding, easy manufacture and so on. However, these windingconfigurations are always suffer from much richer magneto motive force(MMF) harmonic contentsand their MMF waveforms are far from sinusoidal waves compared to regular integer slot winding,and this leads to that the existing the MMF analysis equations built for regular integer and factionalslot distribution windings do not work well for these novel winding configurations, especially forpoly-phase windings, whose phase number is not three. This paper proposes general equations forpredicting the harmonic order for any poly-phase windings. The phase belt, distribution and slot pitchfactors for multiphase winding configuration with highest fundamental are derived. Based on theproposed equations, the key electromagnetic performances of multiphase winding including regularthree phase winding, such as harmonic orders and contents, can be efficiently and effectively predictedand calculated. Finally, Several FEA models are built to verify these equations.

   Semi-Analytical Loss Model for Rotary Transformers
By Henrik KRUPP [View]
[Download]

Abstract: In modern automotive drive applications, ElectricallyExcited Synchronous Machines (ESM) have become analternative to PSMs. Until now, ESMs need slip-rings to supplythe rotor winding. However, carbon brush slip-ring systems aresensitive to environmental influences and produce conductive carbondust during operation. This paper discusses thecreation and utilisation of a semi-analytical loss model for the designof rotary transformes with air-gaps for contactless energy transfer systemsto replace slip-ring systems in electrical machines.The model allows fast and easy loss calculation for topologies like theseries-resonant-converter.It is validated by FEM for three basic core-shapes of rotary transformers.Once a parameter set is determined by FEM for a transformer design, analyticalscaling laws allow fast loss calculation of the copper-losses for arbitrary frequenciesand temperatures.

   Stability criterion for maximum clearing time of a DFIG: an equal area criterion's equivalent for induction generators
By Janailson RODRIGUES LIMA [View]
[Download]

Abstract: Stability is a primordial concern of power systems. From the generator point of view, it means thatthe machine must be able to attain an equilibrium state (possibly the pre-fault state) once the system isback to normal operation. For Synchronous Generators, the Equal Area Criterion (EAC) can be used todetermine the maximum fault clearing time also known as critical clearing time. Such criterion is notvalid for Induction Generators. In fact, only a few works aimed for a stability criterion for Doubly-FedInduction Generators (DFIG). Since the EAC uses the power-angle profile of the synchronous machine,the work done here proposes the use of the power-slip profile of the DFIG. Using the power-slip profile ofa DFIG, an analytic method for critical fault clearing time for a DFIG is developed. The analytic valuescalculated using the criterion are compared with values obtained through simulations showing accurateresults. Hence, the method can be used as an indicator for transient stability for DFIG.

   Variable Reluctance Machine with Synchronous Capacitors
By Yotam FRECHTER [View]
[Download]

Abstract: A synchronous variable reluctance machine (VRM) can work with either a grid connection or a capacitor bank, each would need to provide the machine with positive reactive power to counter the machine inductive coils. Simulation shows that synchronous Variable capacitance could improve the VRM power transfer, when working both as a generator and as a motor. A 3~ synchronous VRM was modelled and simulated. A simulated synchronous capacitor (a device which changes capacitance synchronously with the machine) is connected to the simulated machine.The results show hope that it will be possible to operate the machine in extreme situations. The ability to transfer energy is shown to be improved at the expense of current THD.

EPE 2016 - DS1e: Electrical Machines
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2016 ECCE Europe - Conference > EPE 2016 - Topic 04: Electrical Machines and Drive Systems > EPE 2016 - DS1e: Electrical Machines
	[return to parent folder]

	An Improved Dynamic model for Simulation and Stability Analysis of Brushless Doubly Fed Machines By Mohammad Naser HASHEMNIA	[View] [Download]
Abstract: This paper presents a dynamic model for brushless doubly fed machine including core loss. Using the space vector notation, the conventional equivalent circuit model of the machine is modified to take the core loss effect into account. The proposed method introduces resistances corresponding to stator/rotor core loss components designated to the power/control windings. This model can be used for enhanced time-domain simulations, design of high performance control strategies with core loss detuning effect compensation and also as a tool for stability analysis of the machine drive under different control methods. The dynamic model of a prototype machine is simulated with and without consideration of core loss, and the results are compared with finite element simulations to show the superiority of the proposed model to the conventional one.

	Construction of the FSPM machine and its measurement in comparison with modeled results By Pavel SVETLIK	[View] [Download]
Abstract: This paper deals with construction of a prototype of a flux-switching permanent magnet machine (FSPM). This machine was manufactured on behalf of mathematical calculations and created models. These models are compared with measurement performed on the real machine and some conclusions about quality of manufactured machine are presented.

	Design Methodology of a High Speed Switched Reluctance Generator Drive for Aircrafts By Marcos LAFOZ	[View] [Download]
Abstract: The paper proposes a high speed switched reluctance (SR) drive for aircraft applications, covering the demand of more electric aircrafts (MEA) and defending the particular benefits of this machine technology against others, such as permanent magnet synchronous generators. An appropriate topology of electrical machine and power converter for a high speed DC distribution grid is selected. Firstly, the electromagnetic design of the generator, by means of FEM, is described in detail, paying attention to the problem of the torque ripple and pointing out some solutions to improve it, based on an iterative optimisation of both stator and rotor geometries and phases activation and deactivation angles. Then, the design of power electronics is also analysed, obtaining the required modules and cooling system from a simulation model, using the maximum and average current levels as well as the duty cycles. The model has been developed from the generator electromagnetic design and integrates the control strategy, in charge of controlling the DC-link voltage. An iterative procedure using FEM analysis and the simulation model is also used to validate the thermal and mechanical behaviour of the system. Finally, the integration of the complete electric drive is discussed with the criteria of maintaining the system within the available room and keeping the temperature under the maximum limits. The application of aircraft equipment is specially demanding in terms of robustness, low maintenance, fault tolerance, high temperature and harsh environment, and those are the reasons why the SR generator is a reliable alternative.

	Dynamic load of induction machine due to rotor's eccentricity and bearing clearance By Miroslav BYRTUS	[View] [Download]
Abstract: The most critical part of the induction machines which determines on their life time operation are rolling element bearings. To ensure reliable drive with an induction machine requires deep insight in electro-mechanical dynamics during its operation. The flexible multibody modeling technique enables the simulation of dynamic loads on all drive components. This paper focuses on complex dynamic modeling of machine's behavior in case of eccentrically placed rotor supported by nonlinear bearing with radial clearance. The life time of machine's bearing becomes very important issue of machine's maintenance and reliability and is markedly influenced by any unbalanced forces acting on the rotor. Only the complex electro-mechanical models of the rotor considering all unbalanced electrical and mechanical rotor forces can provide the very detailed information about the bearing load. The methodology of determination of such loading is applied to the 11 kW squirrel-cage induction machine.

	Effect of Micro-filler of Aluminium Oxide on the Mechanical, Electrical and Thermal Properties of Electrical Insulation Systems By Tetjana TOMASKOVA	[View] [Download]
Abstract: Polymers are the preferred materials for use in electrical applications and for power electronics due to their simple of production, light weight and low cost. However, polymers have relatively low thermal conductivity. This paper deals with preparation of epoxy composites with content of micro-filler of aluminum oxide (Al2O3) with high thermal conductivity. Using specific fillers can improve performance parameters of electrical equipment and their thermal, electrical, mechanical properties without the design changes. When it found electrical insulating systems with higher value of thermal conductivity thus it would be possible to increase utilization of rotating machine, alternatively encumber of rotating machine of higher values of current, reduce the size and change the price of electric rotating machines.

	Electromagnetic Calculation of a Wound-Rotor Brushless Doubly-Fed Machine By Fei XIONG	[View] [Download]
Abstract: To quickly and accurately calculate steady-state performance of wound-rotor BDFM, this paper presents an electromagnetic calculation method. A 100 kW wound-rotor BDFM is used as an example to verify the quickness and accuracy of the analytical method by the comparison of the calculation data, two-dimensional (2D) FEM simulation results and experimental data.

	Expanding the Operating Range of Permanent Magnet Synchronous Motors by Using the Optimum Number of Phases By Miriam BOXRIKER	[View] [Download]
Abstract: A holistic approach to determine the optimum number of phases m of an m-phase motor in combinationwith an m-leg inverter for electric vehicle applications is presented. The optimum offers a significantimprovement of the torque and power by approximately 9.6\% over the whole operating range in comparisonto a 3-phase motor and therefore enhances the power and torque density without expanding thedesign parameters of the machine.

	MMF Harmonic Analysis of Polyphase Windings based on the Closed-form Analytical Equation By Xiang REN	[View] [Download]
Abstract: The several new winding configurations, such as fractional slot concentrated winding andconcentrated winding with two slot pitches, have been attracted lots of attentions due to their inherentadvantages such as short ending winding, easy manufacture and so on. However, these windingconfigurations are always suffer from much richer magneto motive force(MMF) harmonic contentsand their MMF waveforms are far from sinusoidal waves compared to regular integer slot winding,and this leads to that the existing the MMF analysis equations built for regular integer and factionalslot distribution windings do not work well for these novel winding configurations, especially forpoly-phase windings, whose phase number is not three. This paper proposes general equations forpredicting the harmonic order for any poly-phase windings. The phase belt, distribution and slot pitchfactors for multiphase winding configuration with highest fundamental are derived. Based on theproposed equations, the key electromagnetic performances of multiphase winding including regularthree phase winding, such as harmonic orders and contents, can be efficiently and effectively predictedand calculated. Finally, Several FEA models are built to verify these equations.

	Semi-Analytical Loss Model for Rotary Transformers By Henrik KRUPP	[View] [Download]
Abstract: In modern automotive drive applications, ElectricallyExcited Synchronous Machines (ESM) have become analternative to PSMs. Until now, ESMs need slip-rings to supplythe rotor winding. However, carbon brush slip-ring systems aresensitive to environmental influences and produce conductive carbondust during operation. This paper discusses thecreation and utilisation of a semi-analytical loss model for the designof rotary transformes with air-gaps for contactless energy transfer systemsto replace slip-ring systems in electrical machines.The model allows fast and easy loss calculation for topologies like theseries-resonant-converter.It is validated by FEM for three basic core-shapes of rotary transformers.Once a parameter set is determined by FEM for a transformer design, analyticalscaling laws allow fast loss calculation of the copper-losses for arbitrary frequenciesand temperatures.

	Stability criterion for maximum clearing time of a DFIG: an equal area criterion's equivalent for induction generators By Janailson RODRIGUES LIMA	[View] [Download]
Abstract: Stability is a primordial concern of power systems. From the generator point of view, it means thatthe machine must be able to attain an equilibrium state (possibly the pre-fault state) once the system isback to normal operation. For Synchronous Generators, the Equal Area Criterion (EAC) can be used todetermine the maximum fault clearing time also known as critical clearing time. Such criterion is notvalid for Induction Generators. In fact, only a few works aimed for a stability criterion for Doubly-FedInduction Generators (DFIG). Since the EAC uses the power-angle profile of the synchronous machine,the work done here proposes the use of the power-slip profile of the DFIG. Using the power-slip profile ofa DFIG, an analytic method for critical fault clearing time for a DFIG is developed. The analytic valuescalculated using the criterion are compared with values obtained through simulations showing accurateresults. Hence, the method can be used as an indicator for transient stability for DFIG.

	Variable Reluctance Machine with Synchronous Capacitors By Yotam FRECHTER	[View] [Download]
Abstract: A synchronous variable reluctance machine (VRM) can work with either a grid connection or a capacitor bank, each would need to provide the machine with positive reactive power to counter the machine inductive coils. Simulation shows that synchronous Variable capacitance could improve the VRM power transfer, when working both as a generator and as a motor. A 3~ synchronous VRM was modelled and simulated. A simulated synchronous capacitor (a device which changes capacitance synchronously with the machine) is connected to the simulated machine.The results show hope that it will be possible to operate the machine in extreme situations. The ability to transfer energy is shown to be improved at the expense of current THD.