EPE Association: EPE 1989 - 46: LATE PAPERS

EPE 1989 - 46: LATE PAPERS
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 1989 - Conference > EPE 1989 - 46: LATE PAPERS

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   CONTROL OF AN ELECTROMAGNETIC VEHICLE SUSPENSION SYSTEM USING THE INMOS TRANSPUTER
By P. K. Sinha; J. C. Hinton; N. S. McLagan [View]
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Abstract: This paper presents a novel transputer-based controller for an electromagnetic suspension system. Because of the relatively fast speed of response and significant force-excitation nonlinearity, analogue controllers are not ideal and linear control laws restrict the operating range. The parallel programming language occam is used to overcome some of the control problems and a novel power amplifier is used to improve the power bandwidth of the system. Some experimental results are included to highlight the effectiveness of the proposed control technique.

   DIMENSIONING THE ACTIVE SUSPENSION SYSTEM OF A WHEELED VEHICLE
By R. Balli; R. Curto; A. De Carli; G. Franceschini [View]
[Download]

Abstract: The actual trend is to use electric drives in active suspension systems for wheeled vehicles. Torque motors are conveniently used as actuators: The main problem consists of setting up the power of single components of the drive in order to obtain the desired performance of the suspension system without over-dimensioning the drive. The aim of the paper is to present a simulation procedure for dimensioning the active and passive components of a suspension system for a formula one racing car. A suitable model of the chassis and suspension systems is worked out by considering the real structure and the possible operating conditions. The parameter of the model are tuned with experimental tests. On the basis of this model, the dimensioning of the actuator is effected by a simulation program. The parameters of the chassis, springs, dampers, and terrain elevation are assumed as variables.

   ZERO-CURRENT SWITCHING-MODE FORWARD QUASI-RESONANT DC-DC POWER CONVERTERS WITH HIGH-FREQUENCY TRANSFORMER LINK USING IGBTS
By L. Ding; M. Nakaoka; Y. Ogino [View]
[Download]

Abstract: This paper presents two forward types of isolated quasi-resonant DC-DC power converters incorporating the resonant switch tank topologies operating under the principle of zero-current switching (ZCS) control scheme. These high power converters featured practically by using new bipolar-mode power semiconductor devices (lGBTs or SI thyristors) for high-frequency switching control are introduced in order to minimize switching losses and stresses, and to reduce EMI noise level, and to utilize the parasitic circuit parameters contained into the high-frequency transformer and power semiconductor devices. The one-switch / two-switch ZCS-forward quasi-resonant converters with high-frequency transformer link including DC regenerating feedback diode loops are newly derived from the conventional PWM forward converters using one-switch / two-switch on the basis of employing current-mode resonant switch concepts with unidirectional or bidirectional topology. The converter circuits demonstrated here are capable of operating in the ultrasonic frequency ranges up to about 1MHz with a significant improvement in performances and high-power density. ln particular, the worklng principle of the two-switch forward ZCS quasi-resonant converter with unidirectional half-cycle current switch is described In detail. Developed is the steady-state operating analysis for ZCS-forward quasi-resonant converter circuit both one-switch and two-switch topologies. The voltage regulation characteristics in steady-state under the operation restrictions and frequency-modulation strategy are illustrated and evaluated using the normalized expressions. The trially-produced forward ZCS quasi-resonant DC-DC converter breadboard using two-IGBTs with unidirectional switch topology suitable for high-power applicatlons are practically built and tested experimentally as battery charger for electrical vehicle system.

   AN ACTIVE POWER FILTER WITH MONITORING OF HARMONIC SPECTRUM
By T. Nakajima; E. Masada [View]
[Download]

Abstract: A novel control scheme for the active filter, 'Component Separate PWM' is presented in this paper. This scheme has notable features both on the way of the compensating current generation and the harmonic component detection. The harmonic current is detected from the power line and is separated into its components by the digital spectral analysis of 'Moving Fourier Transform' or a least square estimation strategy. Thereafter the PWM signal is determined precisely against each of the detected component by the principle of the cosine crossing control with the time varying amplitude signal. These new methods enables to reduce the switching losses and realize high efficiency. Moreover the specified harmonic component that causes a serious interference to the network can be eliminated selectively and effectively. In this case, the active filter with the Component Separate PWM control scheme is regarded as a harmonic monitoring instrument connected to the electrical power system, which can flexibly control the global harmonic current flow in the power line. From the results of numerical case studies, this type of active filter shows good compensation performance even in the dynamic operation.

   MEASUREMENT OF THE REDISTRIBUTION OF CURRENT IN GTO THYRISTORS DURING TURN OFF
By P. R. Palmer; C. M. Johnson [View]
[Download]

Abstract: A method is described for measuring the redistribution of current that occurs between cathode islands in multi-cathode GTO Thyristors at turn-off. Current redistribution has implications for device reliability, since the maximum controllable current for a single island may be reached catastrophically. Results are presented for 400A GTO's showing that the extent of the current redistribution depends upon the storage time allowed, and the anode-cathode voltage reached during the current fall time. From this conclusions are made concerning GTO circuit design and rating of the devices.

   A FREQUENCY COMPENSATED, FAST-ACTING CONTROL SYSTEM FOR STATIC VAR COMPENSATORS
By D. O. Ebockayuck; C. D. Manning [View]
[Download]

Abstract: The Fixed Capacitor Thyristor-Controlled Reactor (FC-TCR) is widely used for AC voltage control on transmission lines and industrial busbars. It has a relatively simple main circuit and its performance depends very much on its controI system. Host reported control systems for static VAR compensators (SVC) employ zero crossing detection and as such suffer from inherently slowed responses and are sensitive to frequency changes, harmonic distortions and transients in the system voltage. This paper presents an SVC control system which employs an inner conduction angle feedback loop, for fast and accurate response, and overcomes the above problems. The control strategy is outlined In detail and tests results are given which demonstrate the effectiveness of the scheme.

   PLUGGING CONTROL OF THYRISTOR FED INDUCTION MOTOR
By N. Tcheir; F. P. Flynn; D. M. Grant [View]
[Download]

Abstract: This paper deals with some aspects of the performance of the three phase induction machine when supplied via an SCR voltage controller. In the present study, a consideration is given to plugging operation with the in-line thyristors present, and a particular attention is paid to the soft starting of the machine. The validity of the analysis was confirmed by the agreement obtained between theoretical calculations and corresponding experimental results.

   USE OF GTO'S IN RESONANT CIRCUIT TOPOLOGIES
By J. M. Leisten; L. Hobson [View]
[Download]

Abstract: Detailed analysis of various forms of resonant converters using a Gate Turn Off Thyristor as the switching device has been carried out. Suitable design procedures have also been formulated. Prototype units based on Buck, half-wave version of the Flyback and Class E resonant converter topologies have been built and evaluated. Each prototype unit has been simulated on a computer using the PSPICE analogue circuit simulation package and the results are presented.

EPE 1989 - 46: LATE PAPERS
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 1989 - Conference > EPE 1989 - 46: LATE PAPERS
	[return to parent folder]

	CONTROL OF AN ELECTROMAGNETIC VEHICLE SUSPENSION SYSTEM USING THE INMOS TRANSPUTER By P. K. Sinha; J. C. Hinton; N. S. McLagan	[View] [Download]
Abstract: This paper presents a novel transputer-based controller for an electromagnetic suspension system. Because of the relatively fast speed of response and significant force-excitation nonlinearity, analogue controllers are not ideal and linear control laws restrict the operating range. The parallel programming language occam is used to overcome some of the control problems and a novel power amplifier is used to improve the power bandwidth of the system. Some experimental results are included to highlight the effectiveness of the proposed control technique.

	DIMENSIONING THE ACTIVE SUSPENSION SYSTEM OF A WHEELED VEHICLE By R. Balli; R. Curto; A. De Carli; G. Franceschini	[View] [Download]
Abstract: The actual trend is to use electric drives in active suspension systems for wheeled vehicles. Torque motors are conveniently used as actuators: The main problem consists of setting up the power of single components of the drive in order to obtain the desired performance of the suspension system without over-dimensioning the drive. The aim of the paper is to present a simulation procedure for dimensioning the active and passive components of a suspension system for a formula one racing car. A suitable model of the chassis and suspension systems is worked out by considering the real structure and the possible operating conditions. The parameter of the model are tuned with experimental tests. On the basis of this model, the dimensioning of the actuator is effected by a simulation program. The parameters of the chassis, springs, dampers, and terrain elevation are assumed as variables.

	ZERO-CURRENT SWITCHING-MODE FORWARD QUASI-RESONANT DC-DC POWER CONVERTERS WITH HIGH-FREQUENCY TRANSFORMER LINK USING IGBTS By L. Ding; M. Nakaoka; Y. Ogino	[View] [Download]
Abstract: This paper presents two forward types of isolated quasi-resonant DC-DC power converters incorporating the resonant switch tank topologies operating under the principle of zero-current switching (ZCS) control scheme. These high power converters featured practically by using new bipolar-mode power semiconductor devices (lGBTs or SI thyristors) for high-frequency switching control are introduced in order to minimize switching losses and stresses, and to reduce EMI noise level, and to utilize the parasitic circuit parameters contained into the high-frequency transformer and power semiconductor devices. The one-switch / two-switch ZCS-forward quasi-resonant converters with high-frequency transformer link including DC regenerating feedback diode loops are newly derived from the conventional PWM forward converters using one-switch / two-switch on the basis of employing current-mode resonant switch concepts with unidirectional or bidirectional topology. The converter circuits demonstrated here are capable of operating in the ultrasonic frequency ranges up to about 1MHz with a significant improvement in performances and high-power density. ln particular, the worklng principle of the two-switch forward ZCS quasi-resonant converter with unidirectional half-cycle current switch is described In detail. Developed is the steady-state operating analysis for ZCS-forward quasi-resonant converter circuit both one-switch and two-switch topologies. The voltage regulation characteristics in steady-state under the operation restrictions and frequency-modulation strategy are illustrated and evaluated using the normalized expressions. The trially-produced forward ZCS quasi-resonant DC-DC converter breadboard using two-IGBTs with unidirectional switch topology suitable for high-power applicatlons are practically built and tested experimentally as battery charger for electrical vehicle system.

	AN ACTIVE POWER FILTER WITH MONITORING OF HARMONIC SPECTRUM By T. Nakajima; E. Masada	[View] [Download]
Abstract: A novel control scheme for the active filter, 'Component Separate PWM' is presented in this paper. This scheme has notable features both on the way of the compensating current generation and the harmonic component detection. The harmonic current is detected from the power line and is separated into its components by the digital spectral analysis of 'Moving Fourier Transform' or a least square estimation strategy. Thereafter the PWM signal is determined precisely against each of the detected component by the principle of the cosine crossing control with the time varying amplitude signal. These new methods enables to reduce the switching losses and realize high efficiency. Moreover the specified harmonic component that causes a serious interference to the network can be eliminated selectively and effectively. In this case, the active filter with the Component Separate PWM control scheme is regarded as a harmonic monitoring instrument connected to the electrical power system, which can flexibly control the global harmonic current flow in the power line. From the results of numerical case studies, this type of active filter shows good compensation performance even in the dynamic operation.

	MEASUREMENT OF THE REDISTRIBUTION OF CURRENT IN GTO THYRISTORS DURING TURN OFF By P. R. Palmer; C. M. Johnson	[View] [Download]
Abstract: A method is described for measuring the redistribution of current that occurs between cathode islands in multi-cathode GTO Thyristors at turn-off. Current redistribution has implications for device reliability, since the maximum controllable current for a single island may be reached catastrophically. Results are presented for 400A GTO's showing that the extent of the current redistribution depends upon the storage time allowed, and the anode-cathode voltage reached during the current fall time. From this conclusions are made concerning GTO circuit design and rating of the devices.

	A FREQUENCY COMPENSATED, FAST-ACTING CONTROL SYSTEM FOR STATIC VAR COMPENSATORS By D. O. Ebockayuck; C. D. Manning	[View] [Download]
Abstract: The Fixed Capacitor Thyristor-Controlled Reactor (FC-TCR) is widely used for AC voltage control on transmission lines and industrial busbars. It has a relatively simple main circuit and its performance depends very much on its controI system. Host reported control systems for static VAR compensators (SVC) employ zero crossing detection and as such suffer from inherently slowed responses and are sensitive to frequency changes, harmonic distortions and transients in the system voltage. This paper presents an SVC control system which employs an inner conduction angle feedback loop, for fast and accurate response, and overcomes the above problems. The control strategy is outlined In detail and tests results are given which demonstrate the effectiveness of the scheme.

	PLUGGING CONTROL OF THYRISTOR FED INDUCTION MOTOR By N. Tcheir; F. P. Flynn; D. M. Grant	[View] [Download]
Abstract: This paper deals with some aspects of the performance of the three phase induction machine when supplied via an SCR voltage controller. In the present study, a consideration is given to plugging operation with the in-line thyristors present, and a particular attention is paid to the soft starting of the machine. The validity of the analysis was confirmed by the agreement obtained between theoretical calculations and corresponding experimental results.

	USE OF GTO'S IN RESONANT CIRCUIT TOPOLOGIES By J. M. Leisten; L. Hobson	[View] [Download]
Abstract: Detailed analysis of various forms of resonant converters using a Gate Turn Off Thyristor as the switching device has been carried out. Suitable design procedures have also been formulated. Prototype units based on Buck, half-wave version of the Flyback and Class E resonant converter topologies have been built and evaluated. Each prototype unit has been simulated on a computer using the PSPICE analogue circuit simulation package and the results are presented.