EPE Association: EPE 2003 - Topic 09b: Reluctance Machines and Drives

EPE 2003 - Topic 09b: Reluctance Machines and Drives
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2003 - Conference > EPE 2003 - Topic 09: ELECTRICAL MACHINES AND ADJUSTABLE SPEED DRIVES > EPE 2003 - Topic 09b: Reluctance Machines and Drives

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   Pumping autonomous reluctance generator by switching the load
By N. Ben-Hail; R. Rabinovici [View]
[Download]

Abstract: The sinusoidal variable reluctance generator (VRG) was discussed and analyzed largely in the literature. In the present paper, the influence of switching the VRG load on enhancing the pumping phenomena is explained. Switching the load of the VRG can contribute to pump more energy into the system, or inversely a smaller VRG can provide the same power by switching its load and therefore the cost of the generator can be reduced. In the following sections a switching single- phase VRG is analyzed. Experimental and simulation results of a switching single-phase and three-phase VRG are discussed.

   Feasibility study of an SR drive for a multi-megawatt high-speed application
By S.J. Watkins; J. Corda [View]
[Download]

Abstract: The paper gives an insight into the main features of an SR drive system from the perspective of a multi-megawatt drive application where the rated speed is typically above ten thousand rev/min and the operating voltage is in the range of several kV. The power electronic converter is based on a topology, which allows the application of multiple voltage levels to the machine's phase windings, while utilising lower voltage, fast switching IGBTs. The system's performance is illustrated by means of computer simulation which includes modelling of the electronics conduction and switching losses together with the copper and iron-loss in the machine.

   Performance enhancement of switched reluctance drives by a novel converter concept
By M. Hiller; J. Hildinger; R. Marquardt [View]
[Download]

Abstract: A new converter topology for switched reluctance (SR) Drives is presented. Compared to conventional converter circuits it offers major degrees of freedom leading to a significant performance enhancement of the drive system. The new converter concept features an additional voltage source for each phase which can be controlled independently of the DC-link voltage. This results in an extended control flexibility, leading to significant improvements regarding efficiency, maximum torque or torque ripple up to maximum speed. Furthermore a second energy source (e.g. supercapacitors) can easily be integrated into the drive system. Because additional chokes are not required, this leads to compact and attractive drive systems for a wide range of applications.

   Acoustic noise comparison between two different switched reluctance motors and an inverter fed induction motor
By J. A. Sanchez; P. Andrada; M. Torrent; J.I. Perat [View]
[Download]

Abstract: An experimental comparison of the acoustic noise emitted by two different switched reluctance motors and an inverter-fed induction motor is reported. Two SRMs of the same size and rated at the same power but with different electromagnetic structures, 6/4 and 12/8, considering various control strategies, are compared with an inverter-fed induction motor (VSI-IM) of similar ratings running under the same working conditions.

   Measurement of magnetic characteristics of switched reluctance motors
By C. S. Dragu; R. Belmans [View]
[Download]

Abstract: The flux-linkage dependency of rotor position and phase current creates a complex problem for the accurate characterization of switched reluctance motors. This paper deals with the SRM static magnetic characteristics measurement using digital processing. Over the last few years a number of analytical algorithms, as well as finite elements modeling and experimental methods have been used to create the magnetization curves of a Switched Reluctance Motor. An overview of the most common methods used to determine the SRM characteristics is given. Using the direct method, the experimental magnetic curves have been obtained for a 1.8 kW four-phase SRM. A digital storage oscilloscope is used to record voltage and current waveforms. The data is loaded to a PC and processed in Matlab. Once the curves have been established, the torque characteristics can be calculated using the well-known co-energy method. The tests carried out prove the correctness of the methodology.

   Optimal firing angles control for four-quadrant operation of an 8/6 SRM
By C. S. Dragu; R. Belmans [View]
[Download]

Abstract: Finding the best firing angles for a specific SRM application is an optimization problem. After reviewing the mathematical model and the motor operation characteristics, an optimization firing angles algorithm with respect to efficiency and average torque maximization in all four quadrants is presented. The algorithm consists of calculating the average torque and efficiency for the full range of turn-on and -off angles. The criteria of choosing the extreme limits and the post-processing algorithm are described. The main conclusions are presented together with simulation results for an 8/6 SRM four-quadrant control.

   Maximum torque control strategy for switched reluctance motors during dc-link disturbances
By F. D'hulster; K. Stockman; R. Belmans [View]
[Download]

Abstract: This paper describes a method to improve the torque performance of a Switched Reluctance Motor (SRM) during dc-link disturbances, using a voltage-dependent control strategy. Voltage sags or excessive load transients can cause a drop in the dc-link voltage, resulting in a loss of mean torque production of the SRM. A voltage dependent control strategy is presented to obtain maximum mean torque, even at lower voltage levels. Optimal control is defined using a nonlinear model of the SRM with drive, based on finite element flux-linkage data. The torque behaviour of the SRM during dc-link disturbances is analyzed, using the analytical electromagnetic system equations, resulting in optimal turn-on and turn-off angles. When analyzing the electromagnetic system equations of a stator phase, it can be seen that, during a drop in the dc-link voltage, the rotor base speed decreases and field weakening is reached at a lower rotor speed. Anticipating the turn-on angle and injecting the phase current before pole-overlap (low back-emf) is the technique proposed in this paper. Finally, the strategy is integrated into a SRM-drive to maximize the torque during startup of a high-inertia industrial machine. If the acceleration is critical, the resulting dc-link voltage drop must be taken into account to reach an optimal control with maximum mean torque production. The considered SRM is a 8/6 SRM with a three level current hysteresis controller.

   Influence of commutations on switched reluctance motor iron losses analytical and experimental studies
By J. Bouchnaif; R. Romary; J. F. Brudny; M. Azizi [View]
[Download]

Abstract: This paper describes a simplified analytical approach to compute iron losses of switched reluctance machines (SRM). The method is based on the combination between Lavers method and analytical calculations of stator and rotor pole flux linkage. The advantages of this method is that no SRM static flux characteristic is needed. It allows to assess qualitatively iron loss generated by the harmonics and also to study the influence of each parameter (current, advanced angle, tooth, ...). The first part of this work describes the analytical model of the stator and rotor pole flux densities, then these quantities are compared with those ones obtained using the finite elements method for a 8/6 SRM. A non linear extrapolation is used with the least squares method for the sinusoidal static iron losses characteristic to exploit the Lavers method. Then the influence of the current climbing on SRM iron loss is discussed. Both The influence of current commutations and regulation on these losses are verified experimentally. It is shown that these two parameters generate a lot of supplementary iron losses usually not considered in the previous theoretical models of iron loss prediction. The theoretical and the experimental results obtained for a 8/6, 2kW, SRM show that the commutation and the current regulation generate a local extreme in the stator pole flux waveforms. The last waveforms are obtained thanks to an auxiliary coil which has been wound around the machine stator pole. The local extreme generate supplementary iron losses reported to that estimated by the proposed procedure.

   Minimizing signal-energy of the course of radial force to reduce noise in variable reluctance motors
By M. Kaiserseder; J. Schmid; W. Amrhein; A. Schumacher [View]
[Download]

Abstract: Radial force is the major origin of acoustic noise in switched reluctance machines. This reduction of noise and vibration can be done by reducing the ratio of harmonics in the fourier spectrum of the radial force. A mathematical analysis leads to an optimization problem that can be solved by the help of genetic algorithms. The resulting radial force is impressed by current shaping.

   Application of genetic algorithms for optimal design of switched reluctance drives
By E. Lomonova; A. Matveev [View]
[Download]

Abstract: This paper analyses the procedure approach and treats the results of applying genetic algorithms (GA) to the design of switched reluctance drives (SRD). The mathematical model of SRD is presented as well as the experimental verification of the model. Dimensioning of a general-purpose SRD is presented as a design example. The dimensioning process is carried out as a solution of multi-objective optimisation task with help of specially developed CAE software named SRD-DASP. The coupling of GA with Experimental Design Method is used to solve the optimisation task.

   On-line feedforward dead-time compensation for PMSM drive
By H.-S. Kim; M.-J. Youn [View]
[Download]

Abstract: In this paper, a new on-line dead-time compensation method is proposed. In the proposed method, the magnitude of the output voltage errors due to dead-time effect is estimated using a time delay control technique and the output voltage errors are calculated using the estimated values and measured current and position information. The calculated voltage errors are fed to voltage references in order to compensate the dead-time effect. The proposed method is applied to a PM synchronous motor drive system and implemented in a digital manner using a digital signal processor (DSP) TMS320C31. The simulations and experiments are carried out for this system to show the effectiveness of the proposed method.

   Sensorless drive for switched reluctance motor based on gradient of phase inductance
By I. Miki; H. Noda [View]
[Download]

Abstract: This paper describes a simple sensorless drive method for switched reluctance motors (SRMs) based on the gradient of phase inductance of SRM. The phase inductance of the SRM varies with the position of the rotor, and the gradient of the active phase inductance is zero when the stator pole of the active phase and the rotor pole are aligned. Therefore, it is possible to drive the SRM without a position sensor by appropriately changing the active phase when the gradient of the phase inductance is zero. In this method, the gradient of the phase inductance can be easily computed using basic equation from the applied voltage to the SRM and the stator current measured. Experimental results with the laboratory test system demonstrate that it is possible to simply control the SRM without a position sensor according to this method.

   Torque-ripple minimisation in switched reluctance motors using a neuro-fuzzy control stategy
By E.P. Kennedy; M. Condon; J. Dowling [View]
[Download]

Abstract: A novel neuro-fuzzy control strategy for torque-ripple minimisation in switched reluctance motors is presented. A compensating signal is added to the output of a PI controller in a current-regulated speed control loop. The neuro-fuzzy compensator is trained offline using data obtained from the steady-state operation of the switched reluctance motor. Simulation results confirm a very significant reduction in the torque-ripple.

   Analysis of low cost switched reluctance motor drives topologies: 2+1 C-dump and the 2+1 with double supply
By W. M. da Silva; P. P. de Paula; D. R. de Sousa; V. A. Tersarioli; C. Goldemberg; A. Van den Bossche [View]
[Download]

Abstract: This paper presents three Switched Reluctance Motor Converter schemes: the conventional asymmetric half-bridge circuit, a new 2+1 C-Dump circuit and a 2+1 converter with double supply. The alternative topologies try to minimize the number of switches, connections, volume and cost while keeping efficiency high. A test bench was conceived to allow the performance evaluation and developments of these converter drives. Simulation and tests results using a 6/4 Switched Reluctance Motor prototype are presented.

   High speed operation of the hybrid stepping motors by a new lead angle control with one pulse voltage
By Y. Okumatsu; A. Kawamura [View]
[Download]

Abstract: This paper presents a new lead angle control method for the high speed operation of the hybrid stepping motor with the one pulse voltage. Experimental result shows that the stable high acceleration and deceleration driving are achieved under both the heavy-load and light-load.

   Sensorless control of a synchronous reluctance motor for compressor of air-conditioner
By D.-H. Cheong; K.-H. Lee; J.-C. Kim [View]
[Download]

Abstract: A sensorless control of a Synchronous Reluctance Motor for compressor of air-conditioner under the large variation load torque into the compressor is presented, and the sensorless variable speed control for energy saving is required with wide range. The sensorless control is the rotor position estimation at low speed is based on the tracking loop and the rotor position at high speed is estimated by using the flux observer. The proposed sensorless control is implemented with the low and high speed sensorless control algorithms using the fixed-point type DSP and is experimentally evaluated.

   Direct torque and flux control of brushless doubly-fed reluctance motors
By M. G. Jovanovic; J. Yu; E. Levi [View]
[Download]

Abstract: A new direct torque (and flux) control (DTC) algorithm for the brushless doubly-fed reluctance machine (BDFRM) is proposed in the paper. This popular control method has been successfully applied to almost all conventional machines but not to doubly-fed drive systems. The scheme developed is generally applicable to the doubly-excited wound rotor induction machine (DEWRIM) as well. The simulation results have demonstrated high controller performance over the entire speed range and under all loading conditions of the machine.

   High performance current controller for switched reluctance motors based on iterative learning
By S.K. Sahoo; S.K. Panda; J.X. Xu [View]
[Download]

Abstract: Switched reluctance motors(SRM) are being considered for variable speed drive applications, due to their simple construction and fault-tolerant power electronic converter configuration. However, inherent torque ripples have prevented their wide-spread application. Many researchers have proposed a cascaded torque control structure where the desired torque is first converted to equivalent phase currents and subsequently a current controller is used to ensure that the desired currents flow through the stator windings. High performance torque control requires accurate current tracking by the inner current controller. Due to the highly non-linear nature of SRM, achieving perfect current tracking is a major challenge. In this paper, we have reviewed various works by earlier researchers on current controllers as reported in the literature and analyzed their merits and demerits. Subsequently, we have proposed and implemented a novel current controller based on Iterative Learning. Experimental results are provided for a 1 hp, 8/6 pole SRM which demonstrate the effectiveness of our proposed scheme in achieving improved current tracking.

EPE 2003 - Topic 09b: Reluctance Machines and Drives
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2003 - Conference > EPE 2003 - Topic 09: ELECTRICAL MACHINES AND ADJUSTABLE SPEED DRIVES > EPE 2003 - Topic 09b: Reluctance Machines and Drives
	[return to parent folder]

	Pumping autonomous reluctance generator by switching the load By N. Ben-Hail; R. Rabinovici	[View] [Download]
Abstract: The sinusoidal variable reluctance generator (VRG) was discussed and analyzed largely in the literature. In the present paper, the influence of switching the VRG load on enhancing the pumping phenomena is explained. Switching the load of the VRG can contribute to pump more energy into the system, or inversely a smaller VRG can provide the same power by switching its load and therefore the cost of the generator can be reduced. In the following sections a switching single- phase VRG is analyzed. Experimental and simulation results of a switching single-phase and three-phase VRG are discussed.

	Feasibility study of an SR drive for a multi-megawatt high-speed application By S.J. Watkins; J. Corda	[View] [Download]
Abstract: The paper gives an insight into the main features of an SR drive system from the perspective of a multi-megawatt drive application where the rated speed is typically above ten thousand rev/min and the operating voltage is in the range of several kV. The power electronic converter is based on a topology, which allows the application of multiple voltage levels to the machine's phase windings, while utilising lower voltage, fast switching IGBTs. The system's performance is illustrated by means of computer simulation which includes modelling of the electronics conduction and switching losses together with the copper and iron-loss in the machine.

	Performance enhancement of switched reluctance drives by a novel converter concept By M. Hiller; J. Hildinger; R. Marquardt	[View] [Download]
Abstract: A new converter topology for switched reluctance (SR) Drives is presented. Compared to conventional converter circuits it offers major degrees of freedom leading to a significant performance enhancement of the drive system. The new converter concept features an additional voltage source for each phase which can be controlled independently of the DC-link voltage. This results in an extended control flexibility, leading to significant improvements regarding efficiency, maximum torque or torque ripple up to maximum speed. Furthermore a second energy source (e.g. supercapacitors) can easily be integrated into the drive system. Because additional chokes are not required, this leads to compact and attractive drive systems for a wide range of applications.

	Acoustic noise comparison between two different switched reluctance motors and an inverter fed induction motor By J. A. Sanchez; P. Andrada; M. Torrent; J.I. Perat	[View] [Download]
Abstract: An experimental comparison of the acoustic noise emitted by two different switched reluctance motors and an inverter-fed induction motor is reported. Two SRMs of the same size and rated at the same power but with different electromagnetic structures, 6/4 and 12/8, considering various control strategies, are compared with an inverter-fed induction motor (VSI-IM) of similar ratings running under the same working conditions.

	Measurement of magnetic characteristics of switched reluctance motors By C. S. Dragu; R. Belmans	[View] [Download]
Abstract: The flux-linkage dependency of rotor position and phase current creates a complex problem for the accurate characterization of switched reluctance motors. This paper deals with the SRM static magnetic characteristics measurement using digital processing. Over the last few years a number of analytical algorithms, as well as finite elements modeling and experimental methods have been used to create the magnetization curves of a Switched Reluctance Motor. An overview of the most common methods used to determine the SRM characteristics is given. Using the direct method, the experimental magnetic curves have been obtained for a 1.8 kW four-phase SRM. A digital storage oscilloscope is used to record voltage and current waveforms. The data is loaded to a PC and processed in Matlab. Once the curves have been established, the torque characteristics can be calculated using the well-known co-energy method. The tests carried out prove the correctness of the methodology.

	Optimal firing angles control for four-quadrant operation of an 8/6 SRM By C. S. Dragu; R. Belmans	[View] [Download]
Abstract: Finding the best firing angles for a specific SRM application is an optimization problem. After reviewing the mathematical model and the motor operation characteristics, an optimization firing angles algorithm with respect to efficiency and average torque maximization in all four quadrants is presented. The algorithm consists of calculating the average torque and efficiency for the full range of turn-on and -off angles. The criteria of choosing the extreme limits and the post-processing algorithm are described. The main conclusions are presented together with simulation results for an 8/6 SRM four-quadrant control.

	Maximum torque control strategy for switched reluctance motors during dc-link disturbances By F. D'hulster; K. Stockman; R. Belmans	[View] [Download]
Abstract: This paper describes a method to improve the torque performance of a Switched Reluctance Motor (SRM) during dc-link disturbances, using a voltage-dependent control strategy. Voltage sags or excessive load transients can cause a drop in the dc-link voltage, resulting in a loss of mean torque production of the SRM. A voltage dependent control strategy is presented to obtain maximum mean torque, even at lower voltage levels. Optimal control is defined using a nonlinear model of the SRM with drive, based on finite element flux-linkage data. The torque behaviour of the SRM during dc-link disturbances is analyzed, using the analytical electromagnetic system equations, resulting in optimal turn-on and turn-off angles. When analyzing the electromagnetic system equations of a stator phase, it can be seen that, during a drop in the dc-link voltage, the rotor base speed decreases and field weakening is reached at a lower rotor speed. Anticipating the turn-on angle and injecting the phase current before pole-overlap (low back-emf) is the technique proposed in this paper. Finally, the strategy is integrated into a SRM-drive to maximize the torque during startup of a high-inertia industrial machine. If the acceleration is critical, the resulting dc-link voltage drop must be taken into account to reach an optimal control with maximum mean torque production. The considered SRM is a 8/6 SRM with a three level current hysteresis controller.

	Influence of commutations on switched reluctance motor iron losses analytical and experimental studies By J. Bouchnaif; R. Romary; J. F. Brudny; M. Azizi	[View] [Download]
Abstract: This paper describes a simplified analytical approach to compute iron losses of switched reluctance machines (SRM). The method is based on the combination between Lavers method and analytical calculations of stator and rotor pole flux linkage. The advantages of this method is that no SRM static flux characteristic is needed. It allows to assess qualitatively iron loss generated by the harmonics and also to study the influence of each parameter (current, advanced angle, tooth, ...). The first part of this work describes the analytical model of the stator and rotor pole flux densities, then these quantities are compared with those ones obtained using the finite elements method for a 8/6 SRM. A non linear extrapolation is used with the least squares method for the sinusoidal static iron losses characteristic to exploit the Lavers method. Then the influence of the current climbing on SRM iron loss is discussed. Both The influence of current commutations and regulation on these losses are verified experimentally. It is shown that these two parameters generate a lot of supplementary iron losses usually not considered in the previous theoretical models of iron loss prediction. The theoretical and the experimental results obtained for a 8/6, 2kW, SRM show that the commutation and the current regulation generate a local extreme in the stator pole flux waveforms. The last waveforms are obtained thanks to an auxiliary coil which has been wound around the machine stator pole. The local extreme generate supplementary iron losses reported to that estimated by the proposed procedure.

	Minimizing signal-energy of the course of radial force to reduce noise in variable reluctance motors By M. Kaiserseder; J. Schmid; W. Amrhein; A. Schumacher	[View] [Download]
Abstract: Radial force is the major origin of acoustic noise in switched reluctance machines. This reduction of noise and vibration can be done by reducing the ratio of harmonics in the fourier spectrum of the radial force. A mathematical analysis leads to an optimization problem that can be solved by the help of genetic algorithms. The resulting radial force is impressed by current shaping.

	Application of genetic algorithms for optimal design of switched reluctance drives By E. Lomonova; A. Matveev	[View] [Download]
Abstract: This paper analyses the procedure approach and treats the results of applying genetic algorithms (GA) to the design of switched reluctance drives (SRD). The mathematical model of SRD is presented as well as the experimental verification of the model. Dimensioning of a general-purpose SRD is presented as a design example. The dimensioning process is carried out as a solution of multi-objective optimisation task with help of specially developed CAE software named SRD-DASP. The coupling of GA with Experimental Design Method is used to solve the optimisation task.

	On-line feedforward dead-time compensation for PMSM drive By H.-S. Kim; M.-J. Youn	[View] [Download]
Abstract: In this paper, a new on-line dead-time compensation method is proposed. In the proposed method, the magnitude of the output voltage errors due to dead-time effect is estimated using a time delay control technique and the output voltage errors are calculated using the estimated values and measured current and position information. The calculated voltage errors are fed to voltage references in order to compensate the dead-time effect. The proposed method is applied to a PM synchronous motor drive system and implemented in a digital manner using a digital signal processor (DSP) TMS320C31. The simulations and experiments are carried out for this system to show the effectiveness of the proposed method.

	Sensorless drive for switched reluctance motor based on gradient of phase inductance By I. Miki; H. Noda	[View] [Download]
Abstract: This paper describes a simple sensorless drive method for switched reluctance motors (SRMs) based on the gradient of phase inductance of SRM. The phase inductance of the SRM varies with the position of the rotor, and the gradient of the active phase inductance is zero when the stator pole of the active phase and the rotor pole are aligned. Therefore, it is possible to drive the SRM without a position sensor by appropriately changing the active phase when the gradient of the phase inductance is zero. In this method, the gradient of the phase inductance can be easily computed using basic equation from the applied voltage to the SRM and the stator current measured. Experimental results with the laboratory test system demonstrate that it is possible to simply control the SRM without a position sensor according to this method.

	Torque-ripple minimisation in switched reluctance motors using a neuro-fuzzy control stategy By E.P. Kennedy; M. Condon; J. Dowling	[View] [Download]
Abstract: A novel neuro-fuzzy control strategy for torque-ripple minimisation in switched reluctance motors is presented. A compensating signal is added to the output of a PI controller in a current-regulated speed control loop. The neuro-fuzzy compensator is trained offline using data obtained from the steady-state operation of the switched reluctance motor. Simulation results confirm a very significant reduction in the torque-ripple.

	Analysis of low cost switched reluctance motor drives topologies: 2+1 C-dump and the 2+1 with double supply By W. M. da Silva; P. P. de Paula; D. R. de Sousa; V. A. Tersarioli; C. Goldemberg; A. Van den Bossche	[View] [Download]
Abstract: This paper presents three Switched Reluctance Motor Converter schemes: the conventional asymmetric half-bridge circuit, a new 2+1 C-Dump circuit and a 2+1 converter with double supply. The alternative topologies try to minimize the number of switches, connections, volume and cost while keeping efficiency high. A test bench was conceived to allow the performance evaluation and developments of these converter drives. Simulation and tests results using a 6/4 Switched Reluctance Motor prototype are presented.

	High speed operation of the hybrid stepping motors by a new lead angle control with one pulse voltage By Y. Okumatsu; A. Kawamura	[View] [Download]
Abstract: This paper presents a new lead angle control method for the high speed operation of the hybrid stepping motor with the one pulse voltage. Experimental result shows that the stable high acceleration and deceleration driving are achieved under both the heavy-load and light-load.

	Sensorless control of a synchronous reluctance motor for compressor of air-conditioner By D.-H. Cheong; K.-H. Lee; J.-C. Kim	[View] [Download]
Abstract: A sensorless control of a Synchronous Reluctance Motor for compressor of air-conditioner under the large variation load torque into the compressor is presented, and the sensorless variable speed control for energy saving is required with wide range. The sensorless control is the rotor position estimation at low speed is based on the tracking loop and the rotor position at high speed is estimated by using the flux observer. The proposed sensorless control is implemented with the low and high speed sensorless control algorithms using the fixed-point type DSP and is experimentally evaluated.

	Direct torque and flux control of brushless doubly-fed reluctance motors By M. G. Jovanovic; J. Yu; E. Levi	[View] [Download]
Abstract: A new direct torque (and flux) control (DTC) algorithm for the brushless doubly-fed reluctance machine (BDFRM) is proposed in the paper. This popular control method has been successfully applied to almost all conventional machines but not to doubly-fed drive systems. The scheme developed is generally applicable to the doubly-excited wound rotor induction machine (DEWRIM) as well. The simulation results have demonstrated high controller performance over the entire speed range and under all loading conditions of the machine.

	High performance current controller for switched reluctance motors based on iterative learning By S.K. Sahoo; S.K. Panda; J.X. Xu	[View] [Download]
Abstract: Switched reluctance motors(SRM) are being considered for variable speed drive applications, due to their simple construction and fault-tolerant power electronic converter configuration. However, inherent torque ripples have prevented their wide-spread application. Many researchers have proposed a cascaded torque control structure where the desired torque is first converted to equivalent phase currents and subsequently a current controller is used to ensure that the desired currents flow through the stator windings. High performance torque control requires accurate current tracking by the inner current controller. Due to the highly non-linear nature of SRM, achieving perfect current tracking is a major challenge. In this paper, we have reviewed various works by earlier researchers on current controllers as reported in the literature and analyzed their merits and demerits. Subsequently, we have proposed and implemented a novel current controller based on Iterative Learning. Experimental results are provided for a 1 hp, 8/6 pole SRM which demonstrate the effectiveness of our proposed scheme in achieving improved current tracking.