EPE Association: EPE 2009 - Subtopic 04-1 - LS: 'Soft Switch Converters (Higher Power)'

EPE 2009 - Subtopic 04-1 - LS: 'Soft Switch Converters (Higher Power)'
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2009 - Conference > EPE 2009 - Topic 04: 'Soft Switch Converters' > EPE 2009 - Subtopic 04-1 - LS: 'Soft Switch Converters (Higher Power)'

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   Designing LLC resonant converters for optimum efficiency
By Claudio ADRAGNA, Silvio DE SIMONE, Claudio SPINI [View]
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Abstract: This paper presents a novel design methodology for the tank circuit of LLC resonant converters, based on a simplified yet accurate model of the steady-state operation in the â€œbelow-resonanceâ€ region. This model is used in a design strategy that aims to design a converter capable of operating with soft-switching in the specified input voltage range, with a load varying from zero up to the maximum specified level, with minimum reactive energy and, then, maximum efficiency level.

   Soft-switching three-phase PWM Inverter Architecture utilizing Coupling Switches between Input and Output Stage
By Klaus RIGBERS, Rik W. DE DONCKER [View]
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Abstract: Power converters for renewable energy systems are expected to have a high lifetime, low costs and a very high efficiency over a wide input power and voltage range (e.g. for photovoltaic and fuel cells). Although very high efficiencies can be achieved with hard-switched power converters operating with state of the art semiconductors, hard-switching results in several disadvantages such as conducted emissions. In addition, the switching frequency is limited to maintain a high efficiency, although a low switching frequency results in a higher required energy storage. In this paper, a three-phase PWM inverter architecture for photovoltaic or fuel cell inverter is presented, which has a wide input voltage range and achieves Zero Voltage Switching (ZVS) for all inverter switches at all operation points. This has been obtained by introducing coupling switches between input and output stage, which also reduce conduction losses. It is shown that, auxiliary passive components are not required.

   Very High Performance AC/DC/DC Converter Architecture for Traction Power Supplies
By ANTONIO COCCIA [View]
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Abstract: This paper presents a very high efficiency AC/DC/DC converter topology suitable for all those applications dealing with high power requirements and good handling of very wide input voltage variations, such as Traction auxiliary services. In particular, to enhance high conversion efficiency together with high reliability and cost reduction, the document addresses the use of a double stage power architecture where the Front-end unit is a 3L PFC (power factor corrector) Boost Converter. The second Converter Stage is instead realized by means of a 3L Half-Bridge LLC Resonant Converter operated both in ZVS and quasi-ZCS mode. Thanks to the 3L PFC Boost Converter it is possible to achieve both, compensation of the wide input voltage range and PF (power factor) very close to unity. The first converter stage, guaranteeing a constant DC voltage applied at the intermediate dc-link, will allow the 2nd Converter Stage -- resonant based - to always work in the optimal operating point, no matter the value of the line voltage. As a matter of fact, high conversion efficiency can always be achieved in all the operating conditions. In the first part, the document discusses the topology architecture describing in details the operation principle of each stage. Next, the converter model and the resonant tank design procedure are presented. In the last section, experimental results, particularly designed for traction applications, are shown to confirm the validity of the theoretical analysis.

EPE 2009 - Subtopic 04-1 - LS: 'Soft Switch Converters (Higher Power)'
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2009 - Conference > EPE 2009 - Topic 04: 'Soft Switch Converters' > EPE 2009 - Subtopic 04-1 - LS: 'Soft Switch Converters (Higher Power)'
	[return to parent folder]

	Designing LLC resonant converters for optimum efficiency By Claudio ADRAGNA, Silvio DE SIMONE, Claudio SPINI	[View] [Download]
Abstract: This paper presents a novel design methodology for the tank circuit of LLC resonant converters, based on a simplified yet accurate model of the steady-state operation in the â€œbelow-resonanceâ€ region. This model is used in a design strategy that aims to design a converter capable of operating with soft-switching in the specified input voltage range, with a load varying from zero up to the maximum specified level, with minimum reactive energy and, then, maximum efficiency level.

	Soft-switching three-phase PWM Inverter Architecture utilizing Coupling Switches between Input and Output Stage By Klaus RIGBERS, Rik W. DE DONCKER	[View] [Download]
Abstract: Power converters for renewable energy systems are expected to have a high lifetime, low costs and a very high efficiency over a wide input power and voltage range (e.g. for photovoltaic and fuel cells). Although very high efficiencies can be achieved with hard-switched power converters operating with state of the art semiconductors, hard-switching results in several disadvantages such as conducted emissions. In addition, the switching frequency is limited to maintain a high efficiency, although a low switching frequency results in a higher required energy storage. In this paper, a three-phase PWM inverter architecture for photovoltaic or fuel cell inverter is presented, which has a wide input voltage range and achieves Zero Voltage Switching (ZVS) for all inverter switches at all operation points. This has been obtained by introducing coupling switches between input and output stage, which also reduce conduction losses. It is shown that, auxiliary passive components are not required.

	Very High Performance AC/DC/DC Converter Architecture for Traction Power Supplies By ANTONIO COCCIA	[View] [Download]
Abstract: This paper presents a very high efficiency AC/DC/DC converter topology suitable for all those applications dealing with high power requirements and good handling of very wide input voltage variations, such as Traction auxiliary services. In particular, to enhance high conversion efficiency together with high reliability and cost reduction, the document addresses the use of a double stage power architecture where the Front-end unit is a 3L PFC (power factor corrector) Boost Converter. The second Converter Stage is instead realized by means of a 3L Half-Bridge LLC Resonant Converter operated both in ZVS and quasi-ZCS mode. Thanks to the 3L PFC Boost Converter it is possible to achieve both, compensation of the wide input voltage range and PF (power factor) very close to unity. The first converter stage, guaranteeing a constant DC voltage applied at the intermediate dc-link, will allow the 2nd Converter Stage -- resonant based - to always work in the optimal operating point, no matter the value of the line voltage. As a matter of fact, high conversion efficiency can always be achieved in all the operating conditions. In the first part, the document discusses the topology architecture describing in details the operation principle of each stage. Next, the converter model and the resonant tank design procedure are presented. In the last section, experimental results, particularly designed for traction applications, are shown to confirm the validity of the theoretical analysis.