EPE Association: EPE 1985 - 24 - Lecture Session 3.10: PERMANENT MAGNET MOTOR DRIVES

EPE 1985 - 24 - Lecture Session 3.10: PERMANENT MAGNET MOTOR DRIVES
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 1985 - Conference > EPE 1985 - 24 - Lecture Session 3.10: PERMANENT MAGNET MOTOR DRIVES

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   MICROCOMPUTER-BASED CASCADE CONTROL FOR POSITION, SPEED AND TORQUE WITH DISTURBANCE OBSERVER FOR AN ELECTRICAL DRIVE SYSTEM
By F. Depping; M. Voits [View]
[Download]

Abstract: To draw full advantage from a direct digital cascade control scheme by applying modern microprocessor technology established continuous control principles may be used as a guideline to be adapted to sampled-data control systems. The criteria of reference frequency response with closed-loop unity gain magnitude (UGM) approach are applied to find optimization rules for the parameters of discrete cancellation controllers. Performance effectiveness is increased by further programmed properties using compensation and observer techniques without additional hardware expenditures. Design objectives are to rapidly follow reference settings and rejecting disturbances effectively. The experimental results confirm the practicability of the strategy pursued and allow the conclusion that it may improve the performance of electrical drive systems with cascade structure.

   A MICROPROCESSOR-CONTROLLED HIGH-ACCURACY DCM SPEED CONTROL SYSTEM
By Chen Tie-Nian, Zhang Chen, Chen Wei-Jun [View]
[Download]

Abstract: A high-accuracy reversible DCM speed control system is developed by using a 8-bit microprocessor. In this system, a staged control method with all digital circuits (digital reference, digital speed measurement and digital firing) is instead of the conventional double closed-loop control algorithm. A "tracking counter-emf" control method is being used at large error in order to optimize the transient behavior, and a single closed-loop linear control method is being used at little error in order to compromise between the algorithm accuracy and response speed of the system. The algorithm is 16-bit word length but the intermediate result in the process is 24-bit word length. The static error of this system is less than 0,05%. The dynamic speed drop is less than 5% and the restoring time is less thsn 0.5 s. The resolution of firing angle is less than 0,01. There is maximum torque and almost no overshoot in the motor starting period. The ratio of the performance to price is superior to common systems.

   A STEP MOTOR DRIVE OPERATING AT MAXIMUM TORQUE
By V. R. Dinov; V. D. Lazarov [View]
[Download]

Abstract: The paper deals with powerful step motors designed for numerical control of machine tools, industrial manipulators and robots. An equation concerning the instantaneous value of the electromagnetic torque has been derived following the analysis of the instantaneous state of the energy and the co-energy of the magnetic system of the motor phases. This allows for the calculation of a family of curves expressing the function average torque - initial angle of the switching on of the phase (the average dynamic error) for a given control frequency. The possibilities to drive the motor with shortened pulses as well as operating it in autocommutation mode and the combination of these two ways of control for achieving maximum torque have been studied.

   DIRECT DIGITAL CONTROL OF A SELF-CONTROLLED SYNCHRONOUS MOTOR WITH PERMANENT MAGNET
By C. Bergmann; P. Goureau; J. P. Louis [View]
[Download]

Abstract: This paper deals with a direct digital control of a two phases synchronous motor with permanent magnet. A 8086 Microprocessor treats the two principal functions: the phase-currents regulations and the self control. The control is realized at high sampling frequency and we present results concerning modelling and implementation.

   SELF-COMMUTATION OF BRUSHLESS DC MOTORS WITHOUT ENCODERS
By M. Jufer [View]
[Download]

Abstract: The brushless DC motor phases are normally switched by a rotor position detector. Usually, it is constituted by 3 Hall sensors, excited by the PM rotor flux density. If this solution is relatively simple, its main limitation is the invariant switching position. In order to keep an optimum torque characteristic, this position must normally vary in a range of ± pi/2 (electric angle). Different alternatives for this solution are presented, mainly related to the back EMF detection:
- the direct back EMF detection through a particular winding or a non-supplied phase;
- the indirect back EMF detection in an analogical way;
- the indirect back EMF detection by a numerical sample method;
- the third harmonic voltage detection.
The two last solutions are presented, applied to the same motor and compared to the Hall sensor technique.

EPE 1985 - 24 - Lecture Session 3.10: PERMANENT MAGNET MOTOR DRIVES
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 1985 - Conference > EPE 1985 - 24 - Lecture Session 3.10: PERMANENT MAGNET MOTOR DRIVES
	[return to parent folder]

	MICROCOMPUTER-BASED CASCADE CONTROL FOR POSITION, SPEED AND TORQUE WITH DISTURBANCE OBSERVER FOR AN ELECTRICAL DRIVE SYSTEM By F. Depping; M. Voits	[View] [Download]
Abstract: To draw full advantage from a direct digital cascade control scheme by applying modern microprocessor technology established continuous control principles may be used as a guideline to be adapted to sampled-data control systems. The criteria of reference frequency response with closed-loop unity gain magnitude (UGM) approach are applied to find optimization rules for the parameters of discrete cancellation controllers. Performance effectiveness is increased by further programmed properties using compensation and observer techniques without additional hardware expenditures. Design objectives are to rapidly follow reference settings and rejecting disturbances effectively. The experimental results confirm the practicability of the strategy pursued and allow the conclusion that it may improve the performance of electrical drive systems with cascade structure.

	A MICROPROCESSOR-CONTROLLED HIGH-ACCURACY DCM SPEED CONTROL SYSTEM By Chen Tie-Nian, Zhang Chen, Chen Wei-Jun	[View] [Download]
Abstract: A high-accuracy reversible DCM speed control system is developed by using a 8-bit microprocessor. In this system, a staged control method with all digital circuits (digital reference, digital speed measurement and digital firing) is instead of the conventional double closed-loop control algorithm. A "tracking counter-emf" control method is being used at large error in order to optimize the transient behavior, and a single closed-loop linear control method is being used at little error in order to compromise between the algorithm accuracy and response speed of the system. The algorithm is 16-bit word length but the intermediate result in the process is 24-bit word length. The static error of this system is less than 0,05%. The dynamic speed drop is less than 5% and the restoring time is less thsn 0.5 s. The resolution of firing angle is less than 0,01. There is maximum torque and almost no overshoot in the motor starting period. The ratio of the performance to price is superior to common systems.

	A STEP MOTOR DRIVE OPERATING AT MAXIMUM TORQUE By V. R. Dinov; V. D. Lazarov	[View] [Download]
Abstract: The paper deals with powerful step motors designed for numerical control of machine tools, industrial manipulators and robots. An equation concerning the instantaneous value of the electromagnetic torque has been derived following the analysis of the instantaneous state of the energy and the co-energy of the magnetic system of the motor phases. This allows for the calculation of a family of curves expressing the function average torque - initial angle of the switching on of the phase (the average dynamic error) for a given control frequency. The possibilities to drive the motor with shortened pulses as well as operating it in autocommutation mode and the combination of these two ways of control for achieving maximum torque have been studied.

	DIRECT DIGITAL CONTROL OF A SELF-CONTROLLED SYNCHRONOUS MOTOR WITH PERMANENT MAGNET By C. Bergmann; P. Goureau; J. P. Louis	[View] [Download]
Abstract: This paper deals with a direct digital control of a two phases synchronous motor with permanent magnet. A 8086 Microprocessor treats the two principal functions: the phase-currents regulations and the self control. The control is realized at high sampling frequency and we present results concerning modelling and implementation.

	SELF-COMMUTATION OF BRUSHLESS DC MOTORS WITHOUT ENCODERS By M. Jufer	[View] [Download]
Abstract: The brushless DC motor phases are normally switched by a rotor position detector. Usually, it is constituted by 3 Hall sensors, excited by the PM rotor flux density. If this solution is relatively simple, its main limitation is the invariant switching position. In order to keep an optimum torque characteristic, this position must normally vary in a range of ± pi/2 (electric angle). Different alternatives for this solution are presented, mainly related to the back EMF detection: - the direct back EMF detection through a particular winding or a non-supplied phase; - the indirect back EMF detection in an analogical way; - the indirect back EMF detection by a numerical sample method; - the third harmonic voltage detection. The two last solutions are presented, applied to the same motor and compared to the Hall sensor technique.