EPE Association: EPE-PEMC 2000 - Topic 01c: Switched Mode Power Supplies and UPS

EPE-PEMC 2000 - Topic 01c: Switched Mode Power Supplies and UPS
You are here: EPE Documents > 04 - EPE-PEMC Conference Proceedings > EPE-PEMC 2000 - Conference > EPE-PEMC 2000 - Topic 01: Power Converters > EPE-PEMC 2000 - Topic 01c: Switched Mode Power Supplies and UPS

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   Adaptive Model of DC/DC Converter in CCM and DCM
By Jakopoviæ Z., Odaviæ M. [View]
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Abstract: Computer simulations are very important in the analysis and design of power electronic converters and systems. In this article an approach of modelling DC/DC converters with circuit oriented simulation programs is discussed. This approach is chosen instead of use of special-purpose programs that manipulate state space equations, because on that way the focus remains on the circuit rather than on the mathematics of the solution. Circuit models of the boost DC/DC converter are presented. Following those approaches, circuit models for other basic converters, such as buck and buck-boost, can be easily derived. These circuit models are called adaptive models because they can recognise an appropriate mode of operation of the DC/DC converter (CCM-continuous conduction mode or DCM-discontinuous conduction mode). The advantage of the adaptive model is also that it can be used in AC analysis. Modern circuit oriented simulation programs (PSpice, SIMPLORER) can linearize such circuit models around the steady-state operating point and on that way enable successful AC analysis without need for deriving analytical expressions.

   Comparison between Hard and Soft Switched DC/AC IGBT Inverters for Usage in Uninterruptible Power Supplies
By Patt M., Renken F.*, Schmidt J. [View]
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Abstract: One main aspect in the development of Uninterruptible Power Supply Inverters (UPS) is the reduction of the losses. This paper shows the effects of reducing the losses by hard and soft switched IGBT Inverters with three different DC-link voltage levels. All inverters are PWM controlled for sinusoidal output voltage. The efficiency of the inverters is measured. A possibility for determining the losses in each semiconductor in the powerparts is presented. The efficiency-curves will be presented and the losses are divided up in switching and forward power losses.

   Design Procedures for Symmetrical Resonant Flyback Converters
By Puklus Z., Szilagyi Cs.P.*, Bíró K. A.** [View]
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Abstract: Symmetrical resonant flyback converters (SRFC) are members of the larger family of symmetrical resonant converters. They represent the only isolated converter alternative in that family, and were developed less than a year ago. Design procedures, control circuits and sample waveforms from working converters were not yet published. This paper provides the derivation from first principles of the fundamental converter equations. It also explains the functioning of the converter, its typical waveforms and introduces a step by step design example, for a Discontinuous Conduction Mode (DCM) converter, switched above resonance. The schematic diagram of the first SRFC built by the authors, and a printed circuit board layout for the gate drive circuit is presented. Captured waveforms and measured parameters are also attached.

   PWM Battery Charger with a Single Switch in the Grid Side
By Segui S., Gimeno F.J., Ibanez F., Sanches C., Alcaniz M. [View]
[Download]

Abstract: Commercial high-power battery chargers usually use controlled rectifiers with SCR semiconductors and phase control in the secondary winding of a transformer connected to the supply grid. Generally, currents handled by the semiconductors are very high, while the voltages are usually far below the nominal voltage of the electrical network. This paper proposes a battery charger that takes advantage of the characteristics of new power semiconductors and works with an IGBT power switch functioning at the voltage level of the grid at a low current. It uses PWM switching technique with current control.

EPE-PEMC 2000 - Topic 01c: Switched Mode Power Supplies and UPS
You are here: EPE Documents > 04 - EPE-PEMC Conference Proceedings > EPE-PEMC 2000 - Conference > EPE-PEMC 2000 - Topic 01: Power Converters > EPE-PEMC 2000 - Topic 01c: Switched Mode Power Supplies and UPS
	[return to parent folder]

	Adaptive Model of DC/DC Converter in CCM and DCM By Jakopoviæ Z., Odaviæ M.	[View] [Download]
Abstract: Computer simulations are very important in the analysis and design of power electronic converters and systems. In this article an approach of modelling DC/DC converters with circuit oriented simulation programs is discussed. This approach is chosen instead of use of special-purpose programs that manipulate state space equations, because on that way the focus remains on the circuit rather than on the mathematics of the solution. Circuit models of the boost DC/DC converter are presented. Following those approaches, circuit models for other basic converters, such as buck and buck-boost, can be easily derived. These circuit models are called adaptive models because they can recognise an appropriate mode of operation of the DC/DC converter (CCM-continuous conduction mode or DCM-discontinuous conduction mode). The advantage of the adaptive model is also that it can be used in AC analysis. Modern circuit oriented simulation programs (PSpice, SIMPLORER) can linearize such circuit models around the steady-state operating point and on that way enable successful AC analysis without need for deriving analytical expressions.

	Comparison between Hard and Soft Switched DC/AC IGBT Inverters for Usage in Uninterruptible Power Supplies By Patt M., Renken F., Schmidt J.*	[View] [Download]
Abstract: One main aspect in the development of Uninterruptible Power Supply Inverters (UPS) is the reduction of the losses. This paper shows the effects of reducing the losses by hard and soft switched IGBT Inverters with three different DC-link voltage levels. All inverters are PWM controlled for sinusoidal output voltage. The efficiency of the inverters is measured. A possibility for determining the losses in each semiconductor in the powerparts is presented. The efficiency-curves will be presented and the losses are divided up in switching and forward power losses.

	Design Procedures for Symmetrical Resonant Flyback Converters By Puklus Z., Szilagyi Cs.P., Bíró K. A.*	[View] [Download]
Abstract: Symmetrical resonant flyback converters (SRFC) are members of the larger family of symmetrical resonant converters. They represent the only isolated converter alternative in that family, and were developed less than a year ago. Design procedures, control circuits and sample waveforms from working converters were not yet published. This paper provides the derivation from first principles of the fundamental converter equations. It also explains the functioning of the converter, its typical waveforms and introduces a step by step design example, for a Discontinuous Conduction Mode (DCM) converter, switched above resonance. The schematic diagram of the first SRFC built by the authors, and a printed circuit board layout for the gate drive circuit is presented. Captured waveforms and measured parameters are also attached.

	PWM Battery Charger with a Single Switch in the Grid Side By Segui S., Gimeno F.J., Ibanez F., Sanches C., Alcaniz M.	[View] [Download]
Abstract: Commercial high-power battery chargers usually use controlled rectifiers with SCR semiconductors and phase control in the secondary winding of a transformer connected to the supply grid. Generally, currents handled by the semiconductors are very high, while the voltages are usually far below the nominal voltage of the electrical network. This paper proposes a battery charger that takes advantage of the characteristics of new power semiconductors and works with an IGBT power switch functioning at the voltage level of the grid at a low current. It uses PWM switching technique with current control.