EPE Association: EPE 2015 - LS3b: Active Components and New Materials

EPE 2015 - LS3b: Active Components and New Materials
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2015 ECCE Europe - Conference > EPE 2015 - Topic 01: Devices, Packaging and System Integration > EPE 2015 - LS3b: Active Components and New Materials

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   6.5kV FREEDM-Pair: Ideal High Power Switch Capitalizing on Si and SiC
By Xiaoqing SONG [View]
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Abstract: 6.5kV Si IGBTs have been used widely in median voltage drives, HVDC, FACTs and traction systems.However, the large switching losses of the Si IGBT limit its switching frequency to only 100Hz to1kHz. On the other hand, wide bandgap (WBG)power devices such as Silicon Carbide (SiC) MOSFETor JFET have demonstrated their superior advantages over Si IGBT, especially in terms ofsignificantly reduced switching losses. A major issue facing large scale adoption of SiC power devicesis still the much higher cost. This paper proposes that the FREEDM-Pair, a Si/SiC hybrid switch,should be an ideal and cost effective switch for high power applications. In the proposed FREEDM-Pair,a SiC MOSFET is connected in parallel with Si IGBT to combine the advantages of IGBT andMOSFET. A 6.5 kV FREEDM-Pair is developed as an example to demonstrate its superiorcost/performance. Experimental results demonstrated 70\% switching loss reduction and the FREEDM-Paircost is estimated to be only 50\% higher than 6.5 kV Si IGBT.

   A new package with Kelvin Source connection for increasing power density in power electronics design
By Vittorio CRISAFULLI [View]
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Abstract: Nowadays, there is a high demand from the power electronics market in having systems more efficientand compact. Packaging has become one of the focus factors in power electronics. With moresophisticated products being developed today, in term of Silicon device like Power MOSFETs andIGBTs, there are higher loads and stresses being put on the packaging of these semiconductormaterials. Today the silicon technology of a power transistor has reached very high integration, havingday by day a smaller die size (smaller dimensions and increased performances). So the impact of theparasitic phenomena starts to become more significant than before. In this paper, the parasitic effect ofthe internal source connection between the die and the package of IGBT will be analyzed. A newFour-lead TO-247 package for the Field stop II IGBT has been will be introduced. The advantage ofthe kelvin connection will be validated against the normal TO-247 in a 4kW Double-switch-forwardconverterprototype. A comparison will be shown between a conventional TO-247 and an innovativeone that allows withdrawing the effect of the parasitic source inductance.

   Investigation of the Thermal Runaway of Silicon Carbide Diodes during Blocking Operation
By Christian BÖDEKER [View]
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Abstract: Schottky-diodes in silicon (Si) are well-known for their problematic blocking behaviour at hightemperatures and high blocking voltages. High leakage currents [1] and self-heating can lead to athermal runaway [2] due to the fatal feedback loop of both. Devices produced of silicon carbide (SiC)are expected to avoid this problem by much lower leakage currents due to the higher Schottky barrierheight [1]. Accordingly, this problem was supposed to be solved for good. However, early SiCSchottky-diodes suffered from non-ideal leakage current densities [3] [4] [5] and were highlyendangered by thermal runaway. In this work the blocking stability of current SiC-Schottky- and SiCpin-diodes is investigated by means of calculation and measurement. Different leakage mechanisms inSchottky- and pin-diodes lead to different voltage and temperature dependencies of the leakagecurrent. The temperature difference _Td, for which a doubling of the leakage current IR occurs, issignificantly higher for SiC-Schottky- and SiC-pin-diodes at nominal voltage than for Si-pin-diodes.Experiments show, that the thermal stability is achieved even under worst cooling conditions or duringhigh temperature operation and thermal runaway during blocking is no longer a limiting factor withinthe specified operating range. However, when going to higher voltages or operating temperatures therisk of thermal runaway has to be reassessed.

   New 1200V full SiC module with 800A rated current
By Eugen WIESNER [View]
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Abstract: This paper is dealing with a newly developed high current 800A/1200V full SiC module containing SiC MOSFETs and antiparallel SiC Schottky Barrier Diodes in a half bridge configuration. Electrical characteristics and thermal performance are described and compared with Si-based IGBT modules. The dependencies of switching characteristics from specific operation conditions are investigated on. The paper concludes with a recommendation of application conditions to benefit most from such a high current full SiC module.

EPE 2015 - LS3b: Active Components and New Materials
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2015 ECCE Europe - Conference > EPE 2015 - Topic 01: Devices, Packaging and System Integration > EPE 2015 - LS3b: Active Components and New Materials
	[return to parent folder]

	6.5kV FREEDM-Pair: Ideal High Power Switch Capitalizing on Si and SiC By Xiaoqing SONG	[View] [Download]
Abstract: 6.5kV Si IGBTs have been used widely in median voltage drives, HVDC, FACTs and traction systems.However, the large switching losses of the Si IGBT limit its switching frequency to only 100Hz to1kHz. On the other hand, wide bandgap (WBG)power devices such as Silicon Carbide (SiC) MOSFETor JFET have demonstrated their superior advantages over Si IGBT, especially in terms ofsignificantly reduced switching losses. A major issue facing large scale adoption of SiC power devicesis still the much higher cost. This paper proposes that the FREEDM-Pair, a Si/SiC hybrid switch,should be an ideal and cost effective switch for high power applications. In the proposed FREEDM-Pair,a SiC MOSFET is connected in parallel with Si IGBT to combine the advantages of IGBT andMOSFET. A 6.5 kV FREEDM-Pair is developed as an example to demonstrate its superiorcost/performance. Experimental results demonstrated 70\% switching loss reduction and the FREEDM-Paircost is estimated to be only 50\% higher than 6.5 kV Si IGBT.

	A new package with Kelvin Source connection for increasing power density in power electronics design By Vittorio CRISAFULLI	[View] [Download]
Abstract: Nowadays, there is a high demand from the power electronics market in having systems more efficientand compact. Packaging has become one of the focus factors in power electronics. With moresophisticated products being developed today, in term of Silicon device like Power MOSFETs andIGBTs, there are higher loads and stresses being put on the packaging of these semiconductormaterials. Today the silicon technology of a power transistor has reached very high integration, havingday by day a smaller die size (smaller dimensions and increased performances). So the impact of theparasitic phenomena starts to become more significant than before. In this paper, the parasitic effect ofthe internal source connection between the die and the package of IGBT will be analyzed. A newFour-lead TO-247 package for the Field stop II IGBT has been will be introduced. The advantage ofthe kelvin connection will be validated against the normal TO-247 in a 4kW Double-switch-forwardconverterprototype. A comparison will be shown between a conventional TO-247 and an innovativeone that allows withdrawing the effect of the parasitic source inductance.

	Investigation of the Thermal Runaway of Silicon Carbide Diodes during Blocking Operation By Christian BÖDEKER	[View] [Download]
Abstract: Schottky-diodes in silicon (Si) are well-known for their problematic blocking behaviour at hightemperatures and high blocking voltages. High leakage currents [1] and self-heating can lead to athermal runaway [2] due to the fatal feedback loop of both. Devices produced of silicon carbide (SiC)are expected to avoid this problem by much lower leakage currents due to the higher Schottky barrierheight [1]. Accordingly, this problem was supposed to be solved for good. However, early SiCSchottky-diodes suffered from non-ideal leakage current densities [3] [4] [5] and were highlyendangered by thermal runaway. In this work the blocking stability of current SiC-Schottky- and SiCpin-diodes is investigated by means of calculation and measurement. Different leakage mechanisms inSchottky- and pin-diodes lead to different voltage and temperature dependencies of the leakagecurrent. The temperature difference _Td, for which a doubling of the leakage current IR occurs, issignificantly higher for SiC-Schottky- and SiC-pin-diodes at nominal voltage than for Si-pin-diodes.Experiments show, that the thermal stability is achieved even under worst cooling conditions or duringhigh temperature operation and thermal runaway during blocking is no longer a limiting factor withinthe specified operating range. However, when going to higher voltages or operating temperatures therisk of thermal runaway has to be reassessed.

	New 1200V full SiC module with 800A rated current By Eugen WIESNER	[View] [Download]
Abstract: This paper is dealing with a newly developed high current 800A/1200V full SiC module containing SiC MOSFETs and antiparallel SiC Schottky Barrier Diodes in a half bridge configuration. Electrical characteristics and thermal performance are described and compared with Si-based IGBT modules. The dependencies of switching characteristics from specific operation conditions are investigated on. The paper concludes with a recommendation of application conditions to benefit most from such a high current full SiC module.