EPE Association: EPE 1987 - 07 - Lecture Session 1.07: CONVERTERS (III)

EPE 1987 - 07 - Lecture Session 1.07: CONVERTERS (III)
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 1987 - Conference > EPE 1987 - 07 - Lecture Session 1.07: CONVERTERS (III)

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   THE DOUBLE FORWARD-FLYBACK CONVERTER
By J. Sebastian; J. Uceda; M. Rico [View]
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Abstract: A new two-output dc-to-dc converter is studied in this paper. In this converter, using only a power transistor, both outputs have been regulated by controlling duty cycle and switching frequency. The number of power components in this new converter is very low, avoiding the use of demagnetizing components of the isolation transformer.

   LOW-LOSS SWITCHING IN SMPS AND HALFBRIDGE CIRCUITS
By K. Löhn [View]
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Abstract: Switching losses can be avoided in classical converters, if the energies stored in parasitic capacitances are recovered in the next transition phase. This requires certain topological and operational conditions which cannot always be met. A squarewave circuit for operating low voltage lamps from the mains is presented taking advantage of these principles.

   INTERACTIVE SWITCHING IN A BRIDGE-LEG
By Jean Barret [View]
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Abstract: In bridge-leg power converters, delays between the logic command signals and the switching of the power devices (the delay in the interface and switches) storage and switching-time of the power device, may generate short circuit in the bridge-leg if not considered. The obvious solution is to introduce dead-time between the switching signals of top and bottom devices in a bridge-leg. This solution limits regulation and linearity of the modulation signal. Using practical examples, interactive switching strategies are analysed which optimise the delay-time between one device switching-off and the other switching-on.

   A NOVEL THREE-PHASE WAVEFORM GENERATOR FOR INVERTER DRIVES
By T. C. Green; J. C. Salmon; B. W. Williams [View]
[Download]

Abstract: A novel digital modulation technique, termed slope modulation, has been developed from delta modulation. The technique naturally copes with some of the common problems encountered with other inverter switching strategies. The main advantages are the well defined minimum on and off times experienced by the switches and the maintainance of full resolution at all output levels. A slope modulator was implemented using standard logic devices and was used as the basis of an entirely digital inverter controller. The nature of the modulator allowed the incorporation of a number of useful practical features such as third harmonic boosting, waveform back tracking and quarter wave symmetry. This was achieved without the use of a microprocessor or any similar complex hardware. The result is a versatile system suitable for production as a gate array.

EPE 1987 - 07 - Lecture Session 1.07: CONVERTERS (III)
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 1987 - Conference > EPE 1987 - 07 - Lecture Session 1.07: CONVERTERS (III)
	[return to parent folder]

	THE DOUBLE FORWARD-FLYBACK CONVERTER By J. Sebastian; J. Uceda; M. Rico	[View] [Download]
Abstract: A new two-output dc-to-dc converter is studied in this paper. In this converter, using only a power transistor, both outputs have been regulated by controlling duty cycle and switching frequency. The number of power components in this new converter is very low, avoiding the use of demagnetizing components of the isolation transformer.

	LOW-LOSS SWITCHING IN SMPS AND HALFBRIDGE CIRCUITS By K. Löhn	[View] [Download]
Abstract: Switching losses can be avoided in classical converters, if the energies stored in parasitic capacitances are recovered in the next transition phase. This requires certain topological and operational conditions which cannot always be met. A squarewave circuit for operating low voltage lamps from the mains is presented taking advantage of these principles.

	INTERACTIVE SWITCHING IN A BRIDGE-LEG By Jean Barret	[View] [Download]
Abstract: In bridge-leg power converters, delays between the logic command signals and the switching of the power devices (the delay in the interface and switches) storage and switching-time of the power device, may generate short circuit in the bridge-leg if not considered. The obvious solution is to introduce dead-time between the switching signals of top and bottom devices in a bridge-leg. This solution limits regulation and linearity of the modulation signal. Using practical examples, interactive switching strategies are analysed which optimise the delay-time between one device switching-off and the other switching-on.

	A NOVEL THREE-PHASE WAVEFORM GENERATOR FOR INVERTER DRIVES By T. C. Green; J. C. Salmon; B. W. Williams	[View] [Download]
Abstract: A novel digital modulation technique, termed slope modulation, has been developed from delta modulation. The technique naturally copes with some of the common problems encountered with other inverter switching strategies. The main advantages are the well defined minimum on and off times experienced by the switches and the maintainance of full resolution at all output levels. A slope modulator was implemented using standard logic devices and was used as the basis of an entirely digital inverter controller. The nature of the modulator allowed the incorporation of a number of useful practical features such as third harmonic boosting, waveform back tracking and quarter wave symmetry. This was achieved without the use of a microprocessor or any similar complex hardware. The result is a versatile system suitable for production as a gate array.