EPE Association: EPE 1987 - 11 - Lecture Session 1.11: PWM CONVERTERS

EPE 1987 - 11 - Lecture Session 1.11: PWM CONVERTERS
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 1987 - Conference > EPE 1987 - 11 - Lecture Session 1.11: PWM CONVERTERS

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   A COMPARISON BETWEEN TWO PWM STRATEGIES: NATURAL SAMPLING AND INSTANTANEOUS FEEDBACK
By G. Friedrich; J. P. Vilain [View]
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Abstract: A relatively small number of control strategies are commonly used to drive chopping converters able to perform on any load, any waveform. The authors campare the two main strategies: natural sampling and instantaneous feedback. After defining some quality criteria, both methods are compared by means of a numerical simulation and a harmonic analysis in order to estimate their respective performance. A prototype (300 V - 20 A), based on a Cascode structure and using the strategy of instantaneous feedback, is described.

   ON THE CONTROL OF A PWM INVERTER SUPPLIED BY A FLUCTUATING VOLTAGE SOURCE AND FEEDING A NON LINEAR LOAD
By B. Chauveau; Y. Cheron; H. Foch; M. Binet [View]
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Abstract: The authors propose the analysis of the operation of a single-phase PWM inverter, taking into account non linearities such as an "impedant" supply or non linear loads (triacs, rectifiers,...). The control action is analysed in order to optimize the load voltage harmonic spectrum. Numerical simulations and experimental results are employed to validate the used method.

   CONTROLLER FOR SINUSOIDAL AND OPTIMIZED PWM WITH PULSE PATTERN CHANGES WITHOUT CURRENT TRANSIENTS
By G. Stanke; B. Nyland [View]
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Abstract: The paper describes the development of a PWM modulator for high power voltage source inverters supplying induction motors. With regard to the small switching frequencies and utilization of the installed power the modulator operates in the modes of free-running and synchronized sinusoidal modulation, optimized modulation and square wave mode. The modulator functions purely digitally on the basis of a microcomputer with minimum hardware requirements and may be coupled to a digital superimposed controller for torque or speed. The hardware and software functions for the different modes are explained in detail. The feasibilities of transitions between the individual modes or different pulse numbers without current transients are evaluated from general considerations. The performance of the modulator was tested on a Iaboratory test bed.

   A FULL NUMERIC INTEGRATED CIRCUIT FOR AN ULTRA HIGH PERFORMANCE P.W.M. MODULATOR
By J. Koulischer; J. L. Van Eck; G. Bingen; J. M. Bodson [View]
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Abstract: This paper describes an integrated circuit providing ultra high quality P.W.M. waveforms. Four different modulation types (asynchronous, synchronous, precalculated, square waves) have been implemented. The transitions between the waveforms have been optimized. Due to a programmable structure, it is possible to choose the most adequate modulation strategy for a given application.

   USE OF THE PULSE WIDTH MODULATION TO IMPROVE THE PERFORMANCES OF RECTIFIERS
By E. Destobbeleer; G. Seguier [View]
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Abstract: Thyristor rectifiers, working with natural commutation, present two drawbacks : they create harmonic currents, they absorb reactive power. In order to reduce these drawbacks, we have studied and tested a rectifier including a current commutating diode bridge directly connected to a series chopper. The chopper control allows each A.C. current half cycle to be in phase with the corresponding one of the feeding voltage, so that no reactive power is then absorbed. Using suitable current pulses in each half cycle, the lower order harmonics can be cancelled. The P.W.M. is interesting only when it is associated with the filtering of the input current and of the output voltage. It allows an interesting reduction of the weight of the input filter. The output filter must eliminate the order of harmonic corresponding to the rectifier pulse number. Theoretical and experimental results show the quality of the obtained characteristics and the particular care which must be taken in determining the filter elements.

EPE 1987 - 11 - Lecture Session 1.11: PWM CONVERTERS
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 1987 - Conference > EPE 1987 - 11 - Lecture Session 1.11: PWM CONVERTERS
	[return to parent folder]

	A COMPARISON BETWEEN TWO PWM STRATEGIES: NATURAL SAMPLING AND INSTANTANEOUS FEEDBACK By G. Friedrich; J. P. Vilain	[View] [Download]
Abstract: A relatively small number of control strategies are commonly used to drive chopping converters able to perform on any load, any waveform. The authors campare the two main strategies: natural sampling and instantaneous feedback. After defining some quality criteria, both methods are compared by means of a numerical simulation and a harmonic analysis in order to estimate their respective performance. A prototype (300 V - 20 A), based on a Cascode structure and using the strategy of instantaneous feedback, is described.

	ON THE CONTROL OF A PWM INVERTER SUPPLIED BY A FLUCTUATING VOLTAGE SOURCE AND FEEDING A NON LINEAR LOAD By B. Chauveau; Y. Cheron; H. Foch; M. Binet	[View] [Download]
Abstract: The authors propose the analysis of the operation of a single-phase PWM inverter, taking into account non linearities such as an "impedant" supply or non linear loads (triacs, rectifiers,...). The control action is analysed in order to optimize the load voltage harmonic spectrum. Numerical simulations and experimental results are employed to validate the used method.

	CONTROLLER FOR SINUSOIDAL AND OPTIMIZED PWM WITH PULSE PATTERN CHANGES WITHOUT CURRENT TRANSIENTS By G. Stanke; B. Nyland	[View] [Download]
Abstract: The paper describes the development of a PWM modulator for high power voltage source inverters supplying induction motors. With regard to the small switching frequencies and utilization of the installed power the modulator operates in the modes of free-running and synchronized sinusoidal modulation, optimized modulation and square wave mode. The modulator functions purely digitally on the basis of a microcomputer with minimum hardware requirements and may be coupled to a digital superimposed controller for torque or speed. The hardware and software functions for the different modes are explained in detail. The feasibilities of transitions between the individual modes or different pulse numbers without current transients are evaluated from general considerations. The performance of the modulator was tested on a Iaboratory test bed.

	A FULL NUMERIC INTEGRATED CIRCUIT FOR AN ULTRA HIGH PERFORMANCE P.W.M. MODULATOR By J. Koulischer; J. L. Van Eck; G. Bingen; J. M. Bodson	[View] [Download]
Abstract: This paper describes an integrated circuit providing ultra high quality P.W.M. waveforms. Four different modulation types (asynchronous, synchronous, precalculated, square waves) have been implemented. The transitions between the waveforms have been optimized. Due to a programmable structure, it is possible to choose the most adequate modulation strategy for a given application.

	USE OF THE PULSE WIDTH MODULATION TO IMPROVE THE PERFORMANCES OF RECTIFIERS By E. Destobbeleer; G. Seguier	[View] [Download]
Abstract: Thyristor rectifiers, working with natural commutation, present two drawbacks : they create harmonic currents, they absorb reactive power. In order to reduce these drawbacks, we have studied and tested a rectifier including a current commutating diode bridge directly connected to a series chopper. The chopper control allows each A.C. current half cycle to be in phase with the corresponding one of the feeding voltage, so that no reactive power is then absorbed. Using suitable current pulses in each half cycle, the lower order harmonics can be cancelled. The P.W.M. is interesting only when it is associated with the filtering of the input current and of the output voltage. It allows an interesting reduction of the weight of the input filter. The output filter must eliminate the order of harmonic corresponding to the rectifier pulse number. Theoretical and experimental results show the quality of the obtained characteristics and the particular care which must be taken in determining the filter elements.