EPE Association: EPE 1989 - 22 - Lecture Session 3.5: SIGNAL PROCESSING

EPE 1989 - 22 - Lecture Session 3.5: SIGNAL PROCESSING
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 1989 - Conference > EPE 1989 - 22 - Lecture Session 3.5: SIGNAL PROCESSING

   [return to parent folder]

   HIGH PERFORMANCE SINGLE CHIP GATING CIRCUIT FOR A PHASE CONTROLLED BRIDGE
By F. P. Dawson; R. Bonert [View]
[Download]

Abstract: The increasing availability of single chip low cost microcontrollers has made it possible to reconsider conventional hardware designs for a variety of gating circuits. This paper, in particular, presents the design of a gating circuit for a six pulse phase controlled bridge utilizing a single chip programmable microcontroller. The dynamic performance of the proposed gating circuit is similar to an analog circuit implementation. The resolution of the firing angle is better than .1 degrees at 60Hz. Moreover, the system is designed to operate over a frequency range of 3 Hz to 120 Hz, and to automatically adapt to changes in line frequency. The experimental verification of the performance criteria are also presented. Finally an example of a special application for a dual bridge AC to DC converter is presented.

   ESTIMATION OF SPEED AND POLE POSITION OF AN INVERTER FED PERMANENT EXCITED SYNCHRONOUS MACHINE
By Ph. K. Sattler; K. Stärker [View]
[Download]

Abstract: To control the speed of a drive consisting of an inverter fed synchronous machine normally the speed has to be measured with a sensor. It is also necessary to measure the pole position to control the current phasor of the machine. In this paper a method is presented to control the speed only by measuring the terminal voltages and line currents of the machine. Speed and pole position are estimated by a Kalman-filter. The model of the permanent excited synchronous machine in the state space, the Kalman-filter algorithm, results of simulation, the practical realization and practical results are shown.

   INDIRECT POSITION DETECTION AT STANDSTILL FOR BRUSHLESS DC AND STEP MOTORS
By Laurent Cardoletti; Alain Cassat; Marcel Jufer [View]
[Download]

Abstract: Classically, the brushless DC motors are self-commutated by means of sensors as Hall devices, resolvers or optical sensors. Some indirect methods are also known, as the back EMF or the third harmonic detection. But these solutions cannot give any information at standstill. The present paper describes a possibility of position detection at standstill, without direct sensor. The position is determined by short current pulses, enabling to detect indirectly the saturation level of the different phases. In order to avoid the temperature effect on the time constants, the messurement is converted in a current difference, with positive and negative current pulses on each phase. So, it is possible to define a logical state corresponding to the actual position with an angular accuracy of one electrical period divided by 2m (m = phase number). Such a method is necessary in order to assure a starting in the good direction. An hazardous first switch on can let start the motor in the wrong direction. So, the proposed system offers the possibility to start surely, without back oscillation. The method is presented through a principle analysis, a process description and experimental measurements.

EPE 1989 - 22 - Lecture Session 3.5: SIGNAL PROCESSING
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 1989 - Conference > EPE 1989 - 22 - Lecture Session 3.5: SIGNAL PROCESSING
	[return to parent folder]

	HIGH PERFORMANCE SINGLE CHIP GATING CIRCUIT FOR A PHASE CONTROLLED BRIDGE By F. P. Dawson; R. Bonert	[View] [Download]
Abstract: The increasing availability of single chip low cost microcontrollers has made it possible to reconsider conventional hardware designs for a variety of gating circuits. This paper, in particular, presents the design of a gating circuit for a six pulse phase controlled bridge utilizing a single chip programmable microcontroller. The dynamic performance of the proposed gating circuit is similar to an analog circuit implementation. The resolution of the firing angle is better than .1 degrees at 60Hz. Moreover, the system is designed to operate over a frequency range of 3 Hz to 120 Hz, and to automatically adapt to changes in line frequency. The experimental verification of the performance criteria are also presented. Finally an example of a special application for a dual bridge AC to DC converter is presented.

	ESTIMATION OF SPEED AND POLE POSITION OF AN INVERTER FED PERMANENT EXCITED SYNCHRONOUS MACHINE By Ph. K. Sattler; K. Stärker	[View] [Download]
Abstract: To control the speed of a drive consisting of an inverter fed synchronous machine normally the speed has to be measured with a sensor. It is also necessary to measure the pole position to control the current phasor of the machine. In this paper a method is presented to control the speed only by measuring the terminal voltages and line currents of the machine. Speed and pole position are estimated by a Kalman-filter. The model of the permanent excited synchronous machine in the state space, the Kalman-filter algorithm, results of simulation, the practical realization and practical results are shown.

	INDIRECT POSITION DETECTION AT STANDSTILL FOR BRUSHLESS DC AND STEP MOTORS By Laurent Cardoletti; Alain Cassat; Marcel Jufer	[View] [Download]
Abstract: Classically, the brushless DC motors are self-commutated by means of sensors as Hall devices, resolvers or optical sensors. Some indirect methods are also known, as the back EMF or the third harmonic detection. But these solutions cannot give any information at standstill. The present paper describes a possibility of position detection at standstill, without direct sensor. The position is determined by short current pulses, enabling to detect indirectly the saturation level of the different phases. In order to avoid the temperature effect on the time constants, the messurement is converted in a current difference, with positive and negative current pulses on each phase. So, it is possible to define a logical state corresponding to the actual position with an angular accuracy of one electrical period divided by 2m (m = phase number). Such a method is necessary in order to assure a starting in the good direction. An hazardous first switch on can let start the motor in the wrong direction. So, the proposed system offers the possibility to start surely, without back oscillation. The method is presented through a principle analysis, a process description and experimental measurements.