EPE Association: EPE 2009 - Subtopic 04-3 - LS: 'Soft Switch Converters (Circuits and Control)'

EPE 2009 - Subtopic 04-3 - LS: 'Soft Switch Converters (Circuits and Control)'
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2009 - Conference > EPE 2009 - Topic 04: 'Soft Switch Converters' > EPE 2009 - Subtopic 04-3 - LS: 'Soft Switch Converters (Circuits and Control)'

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   Frequency / Duty Cycle Control of LCC Resonant Converter Supplying High Voltage Very Low Frequency Test Systems
By Manli HU, Norbert FROEHLEKE, Joachim BOECKER [View]
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Abstract: Very low frequency (VLF) high-voltage (HV) sinusoidal test waveforms are suitable for testing characteristics and insulation qualities of long buried power cables. Unlike as with conventional PWM converters, a newly developed LCC resonant inverter combined with a symmetrical three-stage voltage multiplier rectifier is introduced in this paper to generate VLF HV sinusoidal waves. Due to the wide ranges of output voltage and output load, both the switching frequency and the duty cycle are adopted as control variables. Based on a small-signal equivalent circuit model and a reduced-order transfer function, an average mode current controller is developed for the zero voltage switched LCC resonant converter generating up to 85 kV (RMS) at 0.1 Hz as test voltage. The theoretical analysis and design are verified by simulations and experimental measurements with a prototype setup.

   Parallel connection of resonant converters based on piezoelectric transformers
By Miguel A. JOSE-PRIETO , Juan DIAZ, Fernando NUÃ‘O, David GACIO, Pedro J. VILLEGAS-SAIZ [View]
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Abstract: The aim of the paper is to demonstrate the parallel connection of two converters -based on piezoelectric transformers- given by they are source currents. One of the converters will be the "master" and the other one will be the "slave". Due to this connection, new control strategies are possible, such as duty cycle slave control and so on. It is also probed that the output voltage ripple will be dimnished. Experimental results obtained in a laboratory prototype are also included.

   Current Sharing in Multiphase Boost ZVS Active-Clamping Converters
By Esther DE JODAR, Jose A VILLAREJO, Jacinto JIMENEZ, Miguel MORENO [View]
[Download]

Abstract: Power stages can be connected in parallel to increase the output power. Whenever, it requires current sharing among phases, to optimize the design. A method to achieve the desired current sharing is with equalizing resistors, what it means power losses, or connecting converters with high impedance. In this work has been studied that input impedance of active clamp boost converters can work as a lossless equalizing resistor to achieve current sharing and benefits of soft switching can be added to the benefits of parallel association.

EPE 2009 - Subtopic 04-3 - LS: 'Soft Switch Converters (Circuits and Control)'
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2009 - Conference > EPE 2009 - Topic 04: 'Soft Switch Converters' > EPE 2009 - Subtopic 04-3 - LS: 'Soft Switch Converters (Circuits and Control)'
	[return to parent folder]

	Frequency / Duty Cycle Control of LCC Resonant Converter Supplying High Voltage Very Low Frequency Test Systems By Manli HU, Norbert FROEHLEKE, Joachim BOECKER	[View] [Download]
Abstract: Very low frequency (VLF) high-voltage (HV) sinusoidal test waveforms are suitable for testing characteristics and insulation qualities of long buried power cables. Unlike as with conventional PWM converters, a newly developed LCC resonant inverter combined with a symmetrical three-stage voltage multiplier rectifier is introduced in this paper to generate VLF HV sinusoidal waves. Due to the wide ranges of output voltage and output load, both the switching frequency and the duty cycle are adopted as control variables. Based on a small-signal equivalent circuit model and a reduced-order transfer function, an average mode current controller is developed for the zero voltage switched LCC resonant converter generating up to 85 kV (RMS) at 0.1 Hz as test voltage. The theoretical analysis and design are verified by simulations and experimental measurements with a prototype setup.

	Parallel connection of resonant converters based on piezoelectric transformers By Miguel A. JOSE-PRIETO , Juan DIAZ, Fernando NUÃ‘O, David GACIO, Pedro J. VILLEGAS-SAIZ	[View] [Download]
Abstract: The aim of the paper is to demonstrate the parallel connection of two converters -based on piezoelectric transformers- given by they are source currents. One of the converters will be the "master" and the other one will be the "slave". Due to this connection, new control strategies are possible, such as duty cycle slave control and so on. It is also probed that the output voltage ripple will be dimnished. Experimental results obtained in a laboratory prototype are also included.

	Current Sharing in Multiphase Boost ZVS Active-Clamping Converters By Esther DE JODAR, Jose A VILLAREJO, Jacinto JIMENEZ, Miguel MORENO	[View] [Download]
Abstract: Power stages can be connected in parallel to increase the output power. Whenever, it requires current sharing among phases, to optimize the design. A method to achieve the desired current sharing is with equalizing resistors, what it means power losses, or connecting converters with high impedance. In this work has been studied that input impedance of active clamp boost converters can work as a lossless equalizing resistor to achieve current sharing and benefits of soft switching can be added to the benefits of parallel association.