EPE Association: EPE 1993 - 18 - Lecture Session L6c: DRIVES: SWITCHED RELUCTANCE

EPE 1993 - 18 - Lecture Session L6c: DRIVES: SWITCHED RELUCTANCE
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 1993 - Conference > EPE 1993 - 18 - Lecture Session L6c: DRIVES: SWITCHED RELUCTANCE

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   NEURAL NETWORKS USED FOR TORQUE RIPPLE MINIMISATION FROM A SWITCHED RELUCTANCE MOTOR
By D.S. Reay; T.C. Green; B.W. Williams [View]
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Abstract: The application of neural techniques to the problem of torque ripple minimisation in a switched reluctance motor (SRM) is presented. More conventional techniques for torque linearisation and decoupling are reviewed, after which the application of a neural network to the problem is described. Results obtained experimentally and by simulation of a 4kW IGBT converter and 4-phase SRM are used to illustrate the approach. The networks used have been implemented using both digital signal processor (DSP) and field programmable gate array (FPGA) technologies.

   SENSORLESS METHODS FOR DETERMINING THE ROTOR POSITION OF SWITCHED RELUCTANCE MOTORS
By W. F. Ray; I. H. Al-Bahadly [View]
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Abstract: The attractions of switched reluctance (SR) drives compared to conventional altematives will be significantly enhanced if the optical rotor position sensor can be eliminated. Considerable attention has recently been applied to various methods for sensorless rotor position measurement, generally based on measurement of phase current and inductance or flux and a pre-knowledge of the magnetic characteristics. This paper comprehensively reviews the various methods previously suggested in both papers and patents for operation both at low and high speeds. Lower speed methods generally utilise the introduction of test signals into the phase winding whilst the winding is normally unenergised. Higher speed methods utilise the main excitation current waveform. In addition there are a number of miscellaneous methods which are considered.

   DEVELOPMENT OF SMOOTH TORQUE IN SWITCHED RELUCTANCE MOTORS USING SELF-LEARNING TECHNIQUES
By C. Rochford; R.C. Kavanagh; M.G. Egan; J.M.D. Murphy [View]
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Abstract: Control of the switched or variable reluctance motor is complicated by its nonlinear nature, caused by its doubly salient construction and by the fact that it is designed to operate in magnetic saturation. In this paper, the usually laborious characterisation and commissioning procedures are replaced by an off-line, self-learning algorithm. Numerical approximations are made to the non-linear flux/current/position and torque/current/position characteristics of the reluctance motor by determining the coefficients of approximating functions that model such characteristics. Use of this model allows fast, efficient, on-line torque control suitable for use as an inner loop in velocity and position controllers. Knowledge of the flux-linkage characteristics assimilated by the controller permits the use of feedforward terms to compensate for undesirable non-linearities in the motor.

   TURN-OFF ANGLE CONTROL OF SWITCHED RELUCTANCE MOTORS FOR OPTIMUM TORQUE OUTPUT
By R. Orthmann; H. P. Schöner [View]
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Abstract: A new analytical concept is proposed to determine the turn-off angle for optimum torque output. It is based on the simplified voltage equation of the motor terminal. Simulation results based on a linear motor model are presented to demonstrate the influence of turn-off angle on torque output. The concept enables the on-line calculation of the optimal turnoff-angle. It just requires the knowledge of some state variables within the control loop and some fixed drive parameters. A decrease in torque ripple and subsequently a decrease in acoustic noise is the result. The concept is applicable to the full wave mode and the chopping mode as well.

EPE 1993 - 18 - Lecture Session L6c: DRIVES: SWITCHED RELUCTANCE
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 1993 - Conference > EPE 1993 - 18 - Lecture Session L6c: DRIVES: SWITCHED RELUCTANCE
	[return to parent folder]

	NEURAL NETWORKS USED FOR TORQUE RIPPLE MINIMISATION FROM A SWITCHED RELUCTANCE MOTOR By D.S. Reay; T.C. Green; B.W. Williams	[View] [Download]
Abstract: The application of neural techniques to the problem of torque ripple minimisation in a switched reluctance motor (SRM) is presented. More conventional techniques for torque linearisation and decoupling are reviewed, after which the application of a neural network to the problem is described. Results obtained experimentally and by simulation of a 4kW IGBT converter and 4-phase SRM are used to illustrate the approach. The networks used have been implemented using both digital signal processor (DSP) and field programmable gate array (FPGA) technologies.

	SENSORLESS METHODS FOR DETERMINING THE ROTOR POSITION OF SWITCHED RELUCTANCE MOTORS By W. F. Ray; I. H. Al-Bahadly	[View] [Download]
Abstract: The attractions of switched reluctance (SR) drives compared to conventional altematives will be significantly enhanced if the optical rotor position sensor can be eliminated. Considerable attention has recently been applied to various methods for sensorless rotor position measurement, generally based on measurement of phase current and inductance or flux and a pre-knowledge of the magnetic characteristics. This paper comprehensively reviews the various methods previously suggested in both papers and patents for operation both at low and high speeds. Lower speed methods generally utilise the introduction of test signals into the phase winding whilst the winding is normally unenergised. Higher speed methods utilise the main excitation current waveform. In addition there are a number of miscellaneous methods which are considered.

	DEVELOPMENT OF SMOOTH TORQUE IN SWITCHED RELUCTANCE MOTORS USING SELF-LEARNING TECHNIQUES By C. Rochford; R.C. Kavanagh; M.G. Egan; J.M.D. Murphy	[View] [Download]
Abstract: Control of the switched or variable reluctance motor is complicated by its nonlinear nature, caused by its doubly salient construction and by the fact that it is designed to operate in magnetic saturation. In this paper, the usually laborious characterisation and commissioning procedures are replaced by an off-line, self-learning algorithm. Numerical approximations are made to the non-linear flux/current/position and torque/current/position characteristics of the reluctance motor by determining the coefficients of approximating functions that model such characteristics. Use of this model allows fast, efficient, on-line torque control suitable for use as an inner loop in velocity and position controllers. Knowledge of the flux-linkage characteristics assimilated by the controller permits the use of feedforward terms to compensate for undesirable non-linearities in the motor.

	TURN-OFF ANGLE CONTROL OF SWITCHED RELUCTANCE MOTORS FOR OPTIMUM TORQUE OUTPUT By R. Orthmann; H. P. Schöner	[View] [Download]
Abstract: A new analytical concept is proposed to determine the turn-off angle for optimum torque output. It is based on the simplified voltage equation of the motor terminal. Simulation results based on a linear motor model are presented to demonstrate the influence of turn-off angle on torque output. The concept enables the on-line calculation of the optimal turnoff-angle. It just requires the knowledge of some state variables within the control loop and some fixed drive parameters. A decrease in torque ripple and subsequently a decrease in acoustic noise is the result. The concept is applicable to the full wave mode and the chopping mode as well.