EPE Association: EPE 2007 - Subtopic 15-1

EPE 2007 - Subtopic 15-1 - LS: DC power supplies
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2007 - Conference > EPE 2007 - Topic 15: 'Power supplies' > EPE 2007 - Subtopic 15-1 - LS: DC power supplies

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   Advantages of 3-stage-DC/DC-converters for Server Switch Mode Power Supply (SMPS) applications
By SCHWALBE Ulf; REIMANN Tobias; SCHERF Marko; DEBOY Gerald [View]
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Abstract: This contribution deals with the benefits and the challenges of 3-stage DC/DC converters in SMPS applications. They are compared to state of the art 2-stage DC/DC converters for high power and highest efficiency power supplies focusing on server, telecom AC/DC and battery charger applications as a major market for advanced system solutions. The main difference between a 3-stage SMPS and a conventional 2-stage topology is the existence of an extra stage to assume the output power regulation from the main stage. This publication points out the advantages, the problems and the limits of current-fed pre-regulated 3-stage topologies considering the demands. Further on a comparison of different approaches for a voltage-fed post-regulated 3-stage SMPS is presented. This paper also reconsiders the optimal operation frequency regarding the passive components in a resonant mode converter used in the post-regulated circuit. All presented results are extracted from calculations, simulations or practical measurements on the basis of different 800 W demonstrators with 12 V output.

   Digitalizing Gate Control of High Efficiency, High Frequency and High Power Chopper Circuit SAZZ Using FPGA
By KAWAMURA Atsuo; TSURUTA Yukinori; PAVLOVSKY Martin [View]
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Abstract: In the past, we have proposed a high frequency, high efficiency and high power chopper based on new soft switching topology SAZZ (Snubber Assisted Zero Voltage and Zero Current Transition chopper) for FCEV application. We studied the effectiveness of the SAZZ method by simulation and by experiment. This time we concentrated on digital control of SAZZ converter by FPGA. We report on the status quo of the digitalization of SAZZ gate control.

   Influences of magnetic inductance, leakage inductance and saturable inductance on an active clamp forward converter
By REIMANN Tobias ; DEBOY Gerald; PETZOLDT Juergen; TIAN Jian; SCHERF Marko [View]
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Abstract: In this paper, the influences of the magnetic inductance, leakage inductance and saturable inductor on the behaviour of the active clamp forward are analyzed, and their mathematic solutions are given. Based on the analysis, the other topology variant is proposed, which can be used to reduce the oscillation across the freewheeling switch and improve the ZVS condition of the auxiliary switch in primary side. This leads to improve the EMI behaviour and efficiency because the low voltage rectifier switches could be used. To verify these analyse, some experimental results are presented.

EPE 2007 - Subtopic 15-1 - LS: DC power supplies
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2007 - Conference > EPE 2007 - Topic 15: 'Power supplies' > EPE 2007 - Subtopic 15-1 - LS: DC power supplies
	[return to parent folder]

	Advantages of 3-stage-DC/DC-converters for Server Switch Mode Power Supply (SMPS) applications By SCHWALBE Ulf; REIMANN Tobias; SCHERF Marko; DEBOY Gerald	[View] [Download]
Abstract: This contribution deals with the benefits and the challenges of 3-stage DC/DC converters in SMPS applications. They are compared to state of the art 2-stage DC/DC converters for high power and highest efficiency power supplies focusing on server, telecom AC/DC and battery charger applications as a major market for advanced system solutions. The main difference between a 3-stage SMPS and a conventional 2-stage topology is the existence of an extra stage to assume the output power regulation from the main stage. This publication points out the advantages, the problems and the limits of current-fed pre-regulated 3-stage topologies considering the demands. Further on a comparison of different approaches for a voltage-fed post-regulated 3-stage SMPS is presented. This paper also reconsiders the optimal operation frequency regarding the passive components in a resonant mode converter used in the post-regulated circuit. All presented results are extracted from calculations, simulations or practical measurements on the basis of different 800 W demonstrators with 12 V output.

	Digitalizing Gate Control of High Efficiency, High Frequency and High Power Chopper Circuit SAZZ Using FPGA By KAWAMURA Atsuo; TSURUTA Yukinori; PAVLOVSKY Martin	[View] [Download]
Abstract: In the past, we have proposed a high frequency, high efficiency and high power chopper based on new soft switching topology SAZZ (Snubber Assisted Zero Voltage and Zero Current Transition chopper) for FCEV application. We studied the effectiveness of the SAZZ method by simulation and by experiment. This time we concentrated on digital control of SAZZ converter by FPGA. We report on the status quo of the digitalization of SAZZ gate control.

	Influences of magnetic inductance, leakage inductance and saturable inductance on an active clamp forward converter By REIMANN Tobias ; DEBOY Gerald; PETZOLDT Juergen; TIAN Jian; SCHERF Marko	[View] [Download]
Abstract: In this paper, the influences of the magnetic inductance, leakage inductance and saturable inductor on the behaviour of the active clamp forward are analyzed, and their mathematic solutions are given. Based on the analysis, the other topology variant is proposed, which can be used to reduce the oscillation across the freewheeling switch and improve the ZVS condition of the auxiliary switch in primary side. This leads to improve the EMI behaviour and efficiency because the low voltage rectifier switches could be used. To verify these analyse, some experimental results are presented.