EPE Association: EPE 1997 – 65: Dialogue Session DS5d: RELUCTANCE DRIVES

EPE 1997 – 65: Dialogue Session DS5d: RELUCTANCE DRIVES
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 1997 - Conference > EPE 1997 – 65: Dialogue Session DS5d: RELUCTANCE DRIVES

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   A GENERALISED APPROACH TO TORQUE AND CURRENT COMPUTATION IN SWITCHED RELUCTANCE MOTORS
By Duco W. J. Pulle; Ian R. Petersen [View]
[Download]

Abstract: This paper describes a generalised mathematical model which can be used to model fully pitched or short pitched switched reluctance drive systems. Both nonlinear and mutual inductance effects are fully incorporated whereby extensive use is made of bivariate splines to model the magnetisation characteristics of the motor. Experimental verification of the new method is presented.

   A NEW SINGLE PHASE INDUCTION MOTOR UTILIZING A PARAMETRIC OSCILLATION
By Yoshinori Sakamoto; Mitsuo Natsusaka; Koichi Murakami [View]
[Download]

Abstract: A new type of a parametric motor using a laminated iron core is proposed in this paper. The structure and the fundamental performance characteristics of the motor are discussed. It is clarified that the output and efficiency of the trial motor are comparable to conventional single phase induction motors. The input and output characteristics of the motor are also analyzed, using the modified equivalent circuit of the asymmetric two-phase induction motor. The calculated characteristics agree well with the experimental values in the regions of the slip.

   SWITCHED RELUCTANCE MOTOR WITH 16 STATOR POLES AND 12 ROTOR TEETH
By J. Wolff; H. Späth [View]
[Download]

Abstract: The Elektrotechnisches Institut of the University Karlsruhe has developed, optimxzed and manufactured a Switched Reluctance Drive with power converter and control engineering according to the latest scientific findings. The motor was constructed for the rated output of about 25 kW and for industrial applications. The nominal speed of the test Switched Reluctance Motors is 1500 revolutions per minute. The drive works in all for quadrants and was designed for applications with highest demands for dynamics, constant torque, low noise and highest power output.

   SIMULATION AND CONTROL OF SATURATED SYNCHRONOUS RELUCTANCE MACHINE
By M. Chomat; M. D. McCulloch [View]
[Download]

Abstract: A model of a variable-speed drive with a synchronous reluctance machine (SRM) has been developed. The SRM is modeled employing the space phasor theory with considering the effects of magnetic saturation. Numerical simulations of the operation of variable-frequency inverter fed SRM are presented to show the influence of magnetic saturation on the performance of the machine. The operation of the SRM drive with rotor-oriented vector control taking different values of parameters into account is analyzed and discussed. The effects of saturation on the stability and transient operation are investigated.

   HIGH PERFORMANCE SWITCHED RELUCTANCE MOTOR AND POWER CONVERTER FOR IMPLEMENTATION IN AN ELECTRIC VEHICLE
By Bernd Hexamer [View]
[Download]

Abstract: Electric drives based on a switched reluctance motor (SRM) have some attractive properties: the drives have a high efficiency especially at partial load and switched reluctance motors are less expensive than AC induction motors. Nevertheless, there are some disadvantages like noise and torque ripple caused by the physical working principle of the SRM. With the implementation of a switched reluctance drive (SRD) in an electric vehicle, the suitability of a SRM for traction should be examined. Therefore, a water-cooled power converter with the control-unit and the peripheral devices will be developed. This paper presents the structure and the function of the power converter, the control procedure to balance the switching-losses in the modules, differrent practical realizations and the final realization for the water-cooled power converter with especially designed power modules.

   ROTOR POSITION ESTIMATION OF A SWITCHED RELUCTANCE GENERATOR
By M. Stiebler; K. Liu [View]
[Download]

Abstract: Identification of the rotor position angle is important for the operation of switched reluctance machines (SRM). In this paper an approach was studied by means of simulation to estimate the rotor position of a switched reluctance generator (SRG) on the basis of phase current measurement and integration of flux linkage. The method can also be applied for motor operation. The results suggests the feasibility of sensorless operation.

   A NEW ROTOR POSITION ESTIMATION METHOD FOR SWITCHED RELUCTANCE MOTORS USING PWM VOLTAGE CONTROL
By G. Gallegos-Lopez; P. C. Kjaer; T. J. E. Miller [View]
[Download]

Abstract: The paper describes a new method for indirect sensing of the rotor position in switched reluctance motors using PWM voltage control. The detection method uses the change of the derivative of the phase current to detect the position where a rotor pole and stator pole start to overlap. As no a priori knowledge of motor parameteres is required, the method is applicable to most SRM topologies in a wide power and speed range and for several inverter topologies. It allows medium dynamics. To start up the motor, feedforward method is used which assures robust start-up even under load. The method is comparable to the back EMF position estimation for brushless DC motors. Experimental results demonstrate the robust functionality of the method.

   EFFECT OF CHANGING THE NUMBER OF TURNS ON THE PERFORMANCE OF A SWITCHED RELUCTANCE MOTOR
By J. Corda [View]
[Download]

Abstract: The paper establishes a methodology for examining the effect of hypothetical changes of number of turns per phase winding on the performance of a switched reluctance motor with a given magnetic configuration and specified operating conditions in terms of the output power and speed. The objective of this examination is to select the optimum number of turns. The selection is based on an interative comparison of predicted performance of hypothetical motors with different number of turns. The method used for examining the effect of changing the number of turns includes: (i) transforming the initial input data (magnetisation characteristics and phase winding resistance) used in the mathematical model of the SR motor, to take into account change of the number of turns, and (ii)search for the optimum values of control variables which give maximum efficiency at a required output power and speed.

   CALCULATION OF FORCES IN A HYBRID LINEAR STEPPING MOTOR FOR MACHINE TOOLS
By J. F. Gieras; R. Wang [View]
[Download]

Abstract: A hybrid linear stepping motor (HLSM) with high accuracy and repeatability has been discussed. The motor is fed from a phase current controller and microstepping driver. The finite element method (FEM) is employed for calculating the force. Both the virtual work principle and Maxwell stress tensor have been used. The thrust shows a high content of pulsating force while the normal force is much higher than the thrust. The HLSM is especially suitable for machine tools and high speed positioning systems.

   TWO-PHASE SR MOTOR MODELLING USING A FINITE ELEMENT METHOD COUPLED WITH THE DRIVER
By M. Crivii; M. Jufer [View]
[Download]

Abstract: Usually the analytical methods used to predict the two-phase SR motor performances present a relatively difficult problem due to the special shape of the rotor poles and the high level of saturation. The recent developments of finite element software makes possible to calculate directly the dynamic characteristics of the motor using the moving air gap technique and the coupling with external electronic circuit. The paper presents the application of this features to the dynamic performance calculation of the two-phase SR motor drives, operating in current control mode. The simulation and experimental results are presented.

   OVERLOAD PROTECTION AND MAXIMUM POWER OPERATING POINT CONTROL OF SWITCHED RELUCTANCE MOTOR DRIVES
By Reinhard Orthmann; Alexander Krautstrunk; Hans-Peter Schöner [View]
[Download]

Abstract: When operating switched reluctance motor drives close to their limits, fast changes in operating conditions can cause stall and even damage of the drive. The disappearance of a safety clearance between two excitation cycles causes such malfunction. A method is proposed to determine the safety clearance on-line with the help of system design data and operating parameters. Furthermore algorithms are developed to control the drive at the maximum power operating point even when operating conditions are dynamically changing.

   A NOVEL METHOD FOR THE PREDICTION OF LOSSES IN SWITCHED RELUCTANCE MACHINES
By J. Reinert; R. Inderka; R. W. De Doncker [View]
[Download]

Abstract: An optimal design qf a switched reluctance machine can only be achieved with a precise calculation of the remagnetisation losses. However, due to the non-sinusoidal flux-waveforms and the high degree of saturation an accurate prediction of the losses in the magnetic circuit of a switched reluctance machine is not simple. In this paper a new analytical approach to calculate the losses in the different parts of the core, having different flux waveforms, is presented. The calculation can be performed with standard computer programs. Also, a simulation program implementing this novel method of core-loss calculation is presented. With this simulation the entire drive system can be analysed.

   A NEW CONTROL ANGLE STRATEGY FOR SWITCHED RELUCTANCE MOTOR
By H. Henao; G. A .Capolino; E. Bassily; M. Poloujadoff [View]
[Download]

Abstract: To obtain the best performances for a switched reluctance motor, three factors in control strategy are important : the turn-on and turn-off angle estin1ations, the control law to define the reference phase currents and the current control method. In this paper, the former of these points is analyzed and a new control angle estimation is proposed. This new method has been tested with a trapezoidal phase reference torque model which links the turn-on and turn-off angles, avoiding the inductance regions which produce high current peaks to reduce the torque ripple and consequently the machine noise.

   CONTROL ANALYSIS OF A SWITCHED RELUCTANCE MOTOR
By Milan D. Cundev; Lidija B. Petkovska [View]
[Download]

Abstract: In this paper a novel approach to the optimal control of a switched reluctance motor on the basis of electromagnetic field solution is presented. At first it is required to determine both the Oux linkage characteristics and the characteristics of the coenergy of the motor. After. on the basis of energy concept, the static torque characteristics are computed. The optimal control analysis of the switched reluctance motor is carried out by using the set of solutions of the voltage balance equation for different control parameters by changing the voltage supply and the rotor speed of the motor. On the basis of the analysis of transient characteristics in this paper the optimal control parameters of the switched reluctance motor are predicted and proposed.

   FAST DIGITAL CURRENT CONTROL IN SWITCHED RELUCTANCE MOTOR DRIVE WITHOUT CURRENT FEEDBACK FILTERS
By Frede Blaabjerg; Philip C. Kjaer; Peter O. Rasmussen; Lars Christensen; Steffan Hansen; Jesper R. Kristoffersen [View]
[Download]

Abstract: This paper proposes a method to avoid current feedback filters in fast digital based current loops in switched reluctance drives. The method uses symmetrical modulation of the PWM and synchronously sampling of the current. This gives a noise-free current sampling and no anti-aliasing filter is necessary. A fast FPGA based test system is used for test of the new method. Test results show a significant improved current loop control with the new method compared with traditional methods. It is concluded that the new method can be used in other applications with digital control.

   PARAMETERS AND VOLT-AMPERE RATINGS OF A SYNCHRONOUS RELUCTANCE MOTOR DRIVE FOR FLUX-WEAKENING APPLICATIONS TAKING INTO ACCOUNT IRON SATURATION
By N. Bianchi; S. Bolognani [View]
[Download]

Abstract: The purpose of this paper is to individuate the parameters and the volt-ampere ratings of a synchronous reluctance motor drive to meet a prefixed torque-speed operating region. The effects of the iron saturation are taken into account by an appropriate model of the magnetic characteristic of the motor. The possibility to obtain smaller motor dimensions and higher torque-to-current ratios at base speed by designing the motor with a small saturation current is pointed out in the paper.

EPE 1997 – 65: Dialogue Session DS5d: RELUCTANCE DRIVES
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 1997 - Conference > EPE 1997 – 65: Dialogue Session DS5d: RELUCTANCE DRIVES
	[return to parent folder]

	A GENERALISED APPROACH TO TORQUE AND CURRENT COMPUTATION IN SWITCHED RELUCTANCE MOTORS By Duco W. J. Pulle; Ian R. Petersen	[View] [Download]
Abstract: This paper describes a generalised mathematical model which can be used to model fully pitched or short pitched switched reluctance drive systems. Both nonlinear and mutual inductance effects are fully incorporated whereby extensive use is made of bivariate splines to model the magnetisation characteristics of the motor. Experimental verification of the new method is presented.

	A NEW SINGLE PHASE INDUCTION MOTOR UTILIZING A PARAMETRIC OSCILLATION By Yoshinori Sakamoto; Mitsuo Natsusaka; Koichi Murakami	[View] [Download]
Abstract: A new type of a parametric motor using a laminated iron core is proposed in this paper. The structure and the fundamental performance characteristics of the motor are discussed. It is clarified that the output and efficiency of the trial motor are comparable to conventional single phase induction motors. The input and output characteristics of the motor are also analyzed, using the modified equivalent circuit of the asymmetric two-phase induction motor. The calculated characteristics agree well with the experimental values in the regions of the slip.

	SWITCHED RELUCTANCE MOTOR WITH 16 STATOR POLES AND 12 ROTOR TEETH By J. Wolff; H. Späth	[View] [Download]
Abstract: The Elektrotechnisches Institut of the University Karlsruhe has developed, optimxzed and manufactured a Switched Reluctance Drive with power converter and control engineering according to the latest scientific findings. The motor was constructed for the rated output of about 25 kW and for industrial applications. The nominal speed of the test Switched Reluctance Motors is 1500 revolutions per minute. The drive works in all for quadrants and was designed for applications with highest demands for dynamics, constant torque, low noise and highest power output.

	SIMULATION AND CONTROL OF SATURATED SYNCHRONOUS RELUCTANCE MACHINE By M. Chomat; M. D. McCulloch	[View] [Download]
Abstract: A model of a variable-speed drive with a synchronous reluctance machine (SRM) has been developed. The SRM is modeled employing the space phasor theory with considering the effects of magnetic saturation. Numerical simulations of the operation of variable-frequency inverter fed SRM are presented to show the influence of magnetic saturation on the performance of the machine. The operation of the SRM drive with rotor-oriented vector control taking different values of parameters into account is analyzed and discussed. The effects of saturation on the stability and transient operation are investigated.

	HIGH PERFORMANCE SWITCHED RELUCTANCE MOTOR AND POWER CONVERTER FOR IMPLEMENTATION IN AN ELECTRIC VEHICLE By Bernd Hexamer	[View] [Download]
Abstract: Electric drives based on a switched reluctance motor (SRM) have some attractive properties: the drives have a high efficiency especially at partial load and switched reluctance motors are less expensive than AC induction motors. Nevertheless, there are some disadvantages like noise and torque ripple caused by the physical working principle of the SRM. With the implementation of a switched reluctance drive (SRD) in an electric vehicle, the suitability of a SRM for traction should be examined. Therefore, a water-cooled power converter with the control-unit and the peripheral devices will be developed. This paper presents the structure and the function of the power converter, the control procedure to balance the switching-losses in the modules, differrent practical realizations and the final realization for the water-cooled power converter with especially designed power modules.

	ROTOR POSITION ESTIMATION OF A SWITCHED RELUCTANCE GENERATOR By M. Stiebler; K. Liu	[View] [Download]
Abstract: Identification of the rotor position angle is important for the operation of switched reluctance machines (SRM). In this paper an approach was studied by means of simulation to estimate the rotor position of a switched reluctance generator (SRG) on the basis of phase current measurement and integration of flux linkage. The method can also be applied for motor operation. The results suggests the feasibility of sensorless operation.

	A NEW ROTOR POSITION ESTIMATION METHOD FOR SWITCHED RELUCTANCE MOTORS USING PWM VOLTAGE CONTROL By G. Gallegos-Lopez; P. C. Kjaer; T. J. E. Miller	[View] [Download]
Abstract: The paper describes a new method for indirect sensing of the rotor position in switched reluctance motors using PWM voltage control. The detection method uses the change of the derivative of the phase current to detect the position where a rotor pole and stator pole start to overlap. As no a priori knowledge of motor parameteres is required, the method is applicable to most SRM topologies in a wide power and speed range and for several inverter topologies. It allows medium dynamics. To start up the motor, feedforward method is used which assures robust start-up even under load. The method is comparable to the back EMF position estimation for brushless DC motors. Experimental results demonstrate the robust functionality of the method.

	EFFECT OF CHANGING THE NUMBER OF TURNS ON THE PERFORMANCE OF A SWITCHED RELUCTANCE MOTOR By J. Corda	[View] [Download]
Abstract: The paper establishes a methodology for examining the effect of hypothetical changes of number of turns per phase winding on the performance of a switched reluctance motor with a given magnetic configuration and specified operating conditions in terms of the output power and speed. The objective of this examination is to select the optimum number of turns. The selection is based on an interative comparison of predicted performance of hypothetical motors with different number of turns. The method used for examining the effect of changing the number of turns includes: (i) transforming the initial input data (magnetisation characteristics and phase winding resistance) used in the mathematical model of the SR motor, to take into account change of the number of turns, and (ii)search for the optimum values of control variables which give maximum efficiency at a required output power and speed.

	CALCULATION OF FORCES IN A HYBRID LINEAR STEPPING MOTOR FOR MACHINE TOOLS By J. F. Gieras; R. Wang	[View] [Download]
Abstract: A hybrid linear stepping motor (HLSM) with high accuracy and repeatability has been discussed. The motor is fed from a phase current controller and microstepping driver. The finite element method (FEM) is employed for calculating the force. Both the virtual work principle and Maxwell stress tensor have been used. The thrust shows a high content of pulsating force while the normal force is much higher than the thrust. The HLSM is especially suitable for machine tools and high speed positioning systems.

	TWO-PHASE SR MOTOR MODELLING USING A FINITE ELEMENT METHOD COUPLED WITH THE DRIVER By M. Crivii; M. Jufer	[View] [Download]
Abstract: Usually the analytical methods used to predict the two-phase SR motor performances present a relatively difficult problem due to the special shape of the rotor poles and the high level of saturation. The recent developments of finite element software makes possible to calculate directly the dynamic characteristics of the motor using the moving air gap technique and the coupling with external electronic circuit. The paper presents the application of this features to the dynamic performance calculation of the two-phase SR motor drives, operating in current control mode. The simulation and experimental results are presented.

	OVERLOAD PROTECTION AND MAXIMUM POWER OPERATING POINT CONTROL OF SWITCHED RELUCTANCE MOTOR DRIVES By Reinhard Orthmann; Alexander Krautstrunk; Hans-Peter Schöner	[View] [Download]
Abstract: When operating switched reluctance motor drives close to their limits, fast changes in operating conditions can cause stall and even damage of the drive. The disappearance of a safety clearance between two excitation cycles causes such malfunction. A method is proposed to determine the safety clearance on-line with the help of system design data and operating parameters. Furthermore algorithms are developed to control the drive at the maximum power operating point even when operating conditions are dynamically changing.

	A NOVEL METHOD FOR THE PREDICTION OF LOSSES IN SWITCHED RELUCTANCE MACHINES By J. Reinert; R. Inderka; R. W. De Doncker	[View] [Download]
Abstract: An optimal design qf a switched reluctance machine can only be achieved with a precise calculation of the remagnetisation losses. However, due to the non-sinusoidal flux-waveforms and the high degree of saturation an accurate prediction of the losses in the magnetic circuit of a switched reluctance machine is not simple. In this paper a new analytical approach to calculate the losses in the different parts of the core, having different flux waveforms, is presented. The calculation can be performed with standard computer programs. Also, a simulation program implementing this novel method of core-loss calculation is presented. With this simulation the entire drive system can be analysed.

	A NEW CONTROL ANGLE STRATEGY FOR SWITCHED RELUCTANCE MOTOR By H. Henao; G. A .Capolino; E. Bassily; M. Poloujadoff	[View] [Download]
Abstract: To obtain the best performances for a switched reluctance motor, three factors in control strategy are important : the turn-on and turn-off angle estin1ations, the control law to define the reference phase currents and the current control method. In this paper, the former of these points is analyzed and a new control angle estimation is proposed. This new method has been tested with a trapezoidal phase reference torque model which links the turn-on and turn-off angles, avoiding the inductance regions which produce high current peaks to reduce the torque ripple and consequently the machine noise.

	CONTROL ANALYSIS OF A SWITCHED RELUCTANCE MOTOR By Milan D. Cundev; Lidija B. Petkovska	[View] [Download]
Abstract: In this paper a novel approach to the optimal control of a switched reluctance motor on the basis of electromagnetic field solution is presented. At first it is required to determine both the Oux linkage characteristics and the characteristics of the coenergy of the motor. After. on the basis of energy concept, the static torque characteristics are computed. The optimal control analysis of the switched reluctance motor is carried out by using the set of solutions of the voltage balance equation for different control parameters by changing the voltage supply and the rotor speed of the motor. On the basis of the analysis of transient characteristics in this paper the optimal control parameters of the switched reluctance motor are predicted and proposed.

	FAST DIGITAL CURRENT CONTROL IN SWITCHED RELUCTANCE MOTOR DRIVE WITHOUT CURRENT FEEDBACK FILTERS By Frede Blaabjerg; Philip C. Kjaer; Peter O. Rasmussen; Lars Christensen; Steffan Hansen; Jesper R. Kristoffersen	[View] [Download]
Abstract: This paper proposes a method to avoid current feedback filters in fast digital based current loops in switched reluctance drives. The method uses symmetrical modulation of the PWM and synchronously sampling of the current. This gives a noise-free current sampling and no anti-aliasing filter is necessary. A fast FPGA based test system is used for test of the new method. Test results show a significant improved current loop control with the new method compared with traditional methods. It is concluded that the new method can be used in other applications with digital control.

	PARAMETERS AND VOLT-AMPERE RATINGS OF A SYNCHRONOUS RELUCTANCE MOTOR DRIVE FOR FLUX-WEAKENING APPLICATIONS TAKING INTO ACCOUNT IRON SATURATION By N. Bianchi; S. Bolognani	[View] [Download]
Abstract: The purpose of this paper is to individuate the parameters and the volt-ampere ratings of a synchronous reluctance motor drive to meet a prefixed torque-speed operating region. The effects of the iron saturation are taken into account by an appropriate model of the magnetic characteristic of the motor. The possibility to obtain smaller motor dimensions and higher torque-to-current ratios at base speed by designing the motor with a small saturation current is pointed out in the paper.