EPE Association: EPE 1991 - 37 - Session 4.4: PERMANENT MAGNET MOTOR DRIVES

EPE 1991 - 37 - Session 4.4: PERMANENT MAGNET MOTOR DRIVES
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   BRUSHLESS DC-MOTOR WITH DIGITAL STATE CONTROLLER
By G. Henneberger; T. Lutter [View]
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Abstract: In this paper a digital state controller is presented which has been developed for a selfcommutated permanent magnet excited synchronous machine. In order to use the current precontrol technique the rotor has a magnetic asymmetrical design. Since the machine represents a strong nonlinear system, special methods are necessary in order to develop the controller. Among others, the structure of the machine asks for a cascade controller. Because state controllers exclusively have P-behaviour, a load observer has to be applied to realize stationary precision. The design of the controller and the observer of a brushless dc-motor are described. The function of the controller is proved by simulation techniques and verified by measurements.

   AN INTEGRATED CIRCUIT CONTROLLER FOR BRUSHLESS DC DRIVES
By D. J. Kinniment; P. P. Acarnley; A. G. Jack [View]
[Download]

Abstract: This paper describes the design and operation of an ASIC controller for brushless dc drives of the trapezoidal type. The integrated circuit controller incorporates both torque and speed control loops in separate dedicated processors. The ASIC itself is designed to encompass a very wide range of applications using the minimum number of external cornponents. The applications include: i) the precise speed control of a 10W motor used in a laser scanner, where speed accuracy of 1 part in 10to6 is required, and ii) control of a 10kW motor used in the feed drive of a multi-axis machine tool, where each axis control unit must interact with a host computer which provides overall supervision of the machine.

   A CONTROL METHOD FOR PERMANENT MAGNET SYNCHRONOUS MOTORS WITH TRAPEZOIDAL ELECTROMOTIVE FORCE
By L. Schülting; H.-Ch. Skudelny [View]
[Download]

Abstract: In this paper, a control method for a permanent magnet synchronous motor (PSM) fed by a voltage source inverter (VSI) is described. The electromotive force (EMF) has trapezoidal waveforms. Thus the current in each phase of the PSM must be constant for a third of a period in order to achieve a constant torque. The control method presented here needs only one current sensor in the DC link. During the commutation process in the VSI from one phase to the next an overcurrent occurs in some operating conditions of the drive due to the special form of current sensing. This overcurrent endangers the switches of the inverter and must be prevented. Therefore a control method is developed which considers the commutation process in the VSI. A unit called "chopper" was added to the hysteresis controller to avoid the overcurrent in the switches. This proposed controller shows the same good dynamic and steady-state behaviour as schemes sensing the load currents. General equations of the VSI are given that take into account the status of the whole current controller. Especially during the commutation process the calculations point out that the switches are reliably protected. Detailed simulation results based on the analytical study are presented and verified by laboratory tests.

   SENSORLESS POSITION DETECTION USING THE SUPPLY VOLTAGE FOR A PROGRAMMABLE CURRENT DRIVE FOR SYNCHRONOUS MOTORS
By L. Cardoletti; M. Jufer [View]
[Download]

Abstract: The brushless DC motors and the switched reluctance motors are self-commutated according to their position. Indirect position detections are more and more often developed, using the back-EMF, the third harmonic or the current analysis. For a driver controlled in current, it is possible to self-synchronize the current wave, according to the supply voltage zero-crossing. Such a driver is presented, as an example, it is controlled in current in order to generate a given torque characteristic, without ripple.

   FIVE PHASE TRAPEZIODAL BACK EMF PM SYNCHRONOUS MACHINES AND DRIVES
By P. J. McCleer; J. M. Bailey; J. S. Lawler; B. Banerjee [View]
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Abstract: Surface mount magnet trapezoidal back emf PM synchronous machines, commonly referred to as "Brushless DC" machines, are commercially available in sizes ranges from fractional to tens of horsepower. These machines employ quasi square wave current drive, have concentrated full pitch stator windings and nearly full pitch totor magnet segments, and are almost universally configured as wye connected (iolated neutral) three phase units. In this paper, we show the benefits of extending this type of machine design in both radial and axial air gap versions to five phase, full pitch stator winding geometries. Not only are the torque capacities of similarly sized machines increased, but the peak VA requirements of the switching devices in the coupled solid-state drive circuits are reduced as well. This paper details specific designs for both radial and axial gap five phase machines at the 10 HP level and presents simulated results for the operation of the accompanying 10-device solid-state voltage source drive circuit.

   EXTENDING THE VOLTAGE SATURATED PERFORMANCE OF A DC BRUSHLESS DRIVE
By Antonino Fratta; Alfredo Vagati; Franco Villata [View]
[Download]

Abstract: A commutation technique for DC Brushless drives is presented, able to increase the motoring working area in the T, w plane, for a given supply voltage. Starting from the common two-phase-on scheme, the basic concept is in leading the turn-on angles, while keeping constant the turn-off ones. The method is analysed in detail, by analytical and computational means. Practically obtained results are also given, in the case of a high speed spindle drive.

EPE 1991 - 37 - Session 4.4: PERMANENT MAGNET MOTOR DRIVES
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 1991 - Conference > EPE 1991 - 37 - Session 4.4: PERMANENT MAGNET MOTOR DRIVES
	[return to parent folder]

	BRUSHLESS DC-MOTOR WITH DIGITAL STATE CONTROLLER By G. Henneberger; T. Lutter	[View] [Download]
Abstract: In this paper a digital state controller is presented which has been developed for a selfcommutated permanent magnet excited synchronous machine. In order to use the current precontrol technique the rotor has a magnetic asymmetrical design. Since the machine represents a strong nonlinear system, special methods are necessary in order to develop the controller. Among others, the structure of the machine asks for a cascade controller. Because state controllers exclusively have P-behaviour, a load observer has to be applied to realize stationary precision. The design of the controller and the observer of a brushless dc-motor are described. The function of the controller is proved by simulation techniques and verified by measurements.

	AN INTEGRATED CIRCUIT CONTROLLER FOR BRUSHLESS DC DRIVES By D. J. Kinniment; P. P. Acarnley; A. G. Jack	[View] [Download]
Abstract: This paper describes the design and operation of an ASIC controller for brushless dc drives of the trapezoidal type. The integrated circuit controller incorporates both torque and speed control loops in separate dedicated processors. The ASIC itself is designed to encompass a very wide range of applications using the minimum number of external cornponents. The applications include: i) the precise speed control of a 10W motor used in a laser scanner, where speed accuracy of 1 part in 10to6 is required, and ii) control of a 10kW motor used in the feed drive of a multi-axis machine tool, where each axis control unit must interact with a host computer which provides overall supervision of the machine.

	A CONTROL METHOD FOR PERMANENT MAGNET SYNCHRONOUS MOTORS WITH TRAPEZOIDAL ELECTROMOTIVE FORCE By L. Schülting; H.-Ch. Skudelny	[View] [Download]
Abstract: In this paper, a control method for a permanent magnet synchronous motor (PSM) fed by a voltage source inverter (VSI) is described. The electromotive force (EMF) has trapezoidal waveforms. Thus the current in each phase of the PSM must be constant for a third of a period in order to achieve a constant torque. The control method presented here needs only one current sensor in the DC link. During the commutation process in the VSI from one phase to the next an overcurrent occurs in some operating conditions of the drive due to the special form of current sensing. This overcurrent endangers the switches of the inverter and must be prevented. Therefore a control method is developed which considers the commutation process in the VSI. A unit called "chopper" was added to the hysteresis controller to avoid the overcurrent in the switches. This proposed controller shows the same good dynamic and steady-state behaviour as schemes sensing the load currents. General equations of the VSI are given that take into account the status of the whole current controller. Especially during the commutation process the calculations point out that the switches are reliably protected. Detailed simulation results based on the analytical study are presented and verified by laboratory tests.

	SENSORLESS POSITION DETECTION USING THE SUPPLY VOLTAGE FOR A PROGRAMMABLE CURRENT DRIVE FOR SYNCHRONOUS MOTORS By L. Cardoletti; M. Jufer	[View] [Download]
Abstract: The brushless DC motors and the switched reluctance motors are self-commutated according to their position. Indirect position detections are more and more often developed, using the back-EMF, the third harmonic or the current analysis. For a driver controlled in current, it is possible to self-synchronize the current wave, according to the supply voltage zero-crossing. Such a driver is presented, as an example, it is controlled in current in order to generate a given torque characteristic, without ripple.

	FIVE PHASE TRAPEZIODAL BACK EMF PM SYNCHRONOUS MACHINES AND DRIVES By P. J. McCleer; J. M. Bailey; J. S. Lawler; B. Banerjee	[View] [Download]
Abstract: Surface mount magnet trapezoidal back emf PM synchronous machines, commonly referred to as "Brushless DC" machines, are commercially available in sizes ranges from fractional to tens of horsepower. These machines employ quasi square wave current drive, have concentrated full pitch stator windings and nearly full pitch totor magnet segments, and are almost universally configured as wye connected (iolated neutral) three phase units. In this paper, we show the benefits of extending this type of machine design in both radial and axial air gap versions to five phase, full pitch stator winding geometries. Not only are the torque capacities of similarly sized machines increased, but the peak VA requirements of the switching devices in the coupled solid-state drive circuits are reduced as well. This paper details specific designs for both radial and axial gap five phase machines at the 10 HP level and presents simulated results for the operation of the accompanying 10-device solid-state voltage source drive circuit.

	EXTENDING THE VOLTAGE SATURATED PERFORMANCE OF A DC BRUSHLESS DRIVE By Antonino Fratta; Alfredo Vagati; Franco Villata	[View] [Download]
Abstract: A commutation technique for DC Brushless drives is presented, able to increase the motoring working area in the T, w plane, for a given supply voltage. Starting from the common two-phase-on scheme, the basic concept is in leading the turn-on angles, while keeping constant the turn-off ones. The method is analysed in detail, by analytical and computational means. Practically obtained results are also given, in the case of a high speed spindle drive.