EPE Association: EPE 2016 - LS2a: Soft Switching Converters

EPE 2016 - LS2a: Soft Switching Converters
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2016 ECCE Europe - Conference > EPE 2016 - Topic 02: Power Converter Topologies and Design > EPE 2016 - LS2a: Soft Switching Converters

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   A Novel Commutation Sequence for the Three-Level Active Neutral-Point-Clamped Inverter to Aid in Splitting Switching and Conduction Losses Among the Semiconduct
By Luis CABALLERO [View]
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Abstract: The three-level neutral-point-clamped (3L-NPC) topology is competitive in the large wind energyconversion systems (WECS) thanks to its simple implementation and proper performance compared toother topologies. However, the 3L-NPC topology does not allow distributing power losses evenlyamong the switching devices, which limits its output power capability. Current literature focuses onthe three-level active neutral-point-clamped (3L-ANPC) as an evolution of the 3L-NPC, enabling amore even power loss distribution. However, some devices still suffer from significant switching andconduction power losses with typical commutation sequences. This paper proposes a novelcommutation sequence for a 3L-ANPC inverter leg to force that each device mainly withstands eitherswitching or conduction losses. This enables the selection of optimum devices for each position,resulting in an improved converter loss distribution, thermal performance, efficiency, and outputpower capability. A 2 MW low-voltage WECS is simulated with an electro-thermal model developedin PLECS, reaching a reduction of around 16\% in total switching losses. In addition, an enhancedthermal performance is achieved, reducing the maximum junction temperature increase above ambienttemperature, on average for all devices, around 4\%. The thermal advantages are considerably higher incertain devices, reaching maximum reductions of around 17\% in the maximum junction temperatureincrease above ambient temperature and about 40\% in the maximum device junction temperaturevariation. All reductions are with reference to the conventional commutation sequence.

   A ZCT Soft Switching Approach for T-type 3-level Converter - Analysis, Design Guideline, Experiment and Issues
By Yanhong ZHANG [View]
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Abstract: A zero current transition (ZCT) approach for T-type 3-level converter is presented in the paper. Through State-Plane analysis of its voltage and current trajectory in 4 operation zones, a design guideline is developed. The proposal is verified in a 10KVA converter, which is a mini-model of 500KVA UPS product. Preliminary test result shows that diode reverse recovery is a big concern for such ZCT soft switching techniques. Countermeasures for reducing the impact of diode reverse recovery are tested and discussed.

   Soft-Switching Three-Phase AC to DC Converter Isolated By High-Frequency Transformer
By Kazuma SUZUKI [View]
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Abstract: This paper presents a soft-switching three-phase AC to DC converter isolated by high-frequency transformer. The-soft switching conditions are indicated and the soft-switching control method are derived. The effectiveness of the proposed circuit and control method are verified by experiments using a 1 kW prototype.

   Step Up DC-DC Converter for Automotive Application
By Alexander ISURIN [View]
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Abstract: Electrification of vehicle accessories often requires the application of low voltage high current step up DC-DC converter with a high voltage gain ratio qualified for use in an automotive environment. The proposed topology provides step-up on low voltage side that reduces the transformer turns ratio, leading to a simplified transformer design with reduced cost and increased efficiency which is especially important with low input voltage (10-20VDC) at 2-4kW or more. Fundamental operation of the topology has been and verified by simulation in NL-5. An experimental prototype has been built, which verifies the performance and high efficiency of the circuit topology. High efficiency DC-DC (94\%, 3kW and 94.5\%, 10kW) prototypes have been built. This topology is a better solution for higher power at low input voltage than parallel input stages. It was compared with other topologies by cost and performance.

EPE 2016 - LS2a: Soft Switching Converters
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2016 ECCE Europe - Conference > EPE 2016 - Topic 02: Power Converter Topologies and Design > EPE 2016 - LS2a: Soft Switching Converters
	[return to parent folder]

	A Novel Commutation Sequence for the Three-Level Active Neutral-Point-Clamped Inverter to Aid in Splitting Switching and Conduction Losses Among the Semiconduct By Luis CABALLERO	[View] [Download]
Abstract: The three-level neutral-point-clamped (3L-NPC) topology is competitive in the large wind energyconversion systems (WECS) thanks to its simple implementation and proper performance compared toother topologies. However, the 3L-NPC topology does not allow distributing power losses evenlyamong the switching devices, which limits its output power capability. Current literature focuses onthe three-level active neutral-point-clamped (3L-ANPC) as an evolution of the 3L-NPC, enabling amore even power loss distribution. However, some devices still suffer from significant switching andconduction power losses with typical commutation sequences. This paper proposes a novelcommutation sequence for a 3L-ANPC inverter leg to force that each device mainly withstands eitherswitching or conduction losses. This enables the selection of optimum devices for each position,resulting in an improved converter loss distribution, thermal performance, efficiency, and outputpower capability. A 2 MW low-voltage WECS is simulated with an electro-thermal model developedin PLECS, reaching a reduction of around 16\% in total switching losses. In addition, an enhancedthermal performance is achieved, reducing the maximum junction temperature increase above ambienttemperature, on average for all devices, around 4\%. The thermal advantages are considerably higher incertain devices, reaching maximum reductions of around 17\% in the maximum junction temperatureincrease above ambient temperature and about 40\% in the maximum device junction temperaturevariation. All reductions are with reference to the conventional commutation sequence.

	A ZCT Soft Switching Approach for T-type 3-level Converter - Analysis, Design Guideline, Experiment and Issues By Yanhong ZHANG	[View] [Download]
Abstract: A zero current transition (ZCT) approach for T-type 3-level converter is presented in the paper. Through State-Plane analysis of its voltage and current trajectory in 4 operation zones, a design guideline is developed. The proposal is verified in a 10KVA converter, which is a mini-model of 500KVA UPS product. Preliminary test result shows that diode reverse recovery is a big concern for such ZCT soft switching techniques. Countermeasures for reducing the impact of diode reverse recovery are tested and discussed.

	Soft-Switching Three-Phase AC to DC Converter Isolated By High-Frequency Transformer By Kazuma SUZUKI	[View] [Download]
Abstract: This paper presents a soft-switching three-phase AC to DC converter isolated by high-frequency transformer. The-soft switching conditions are indicated and the soft-switching control method are derived. The effectiveness of the proposed circuit and control method are verified by experiments using a 1 kW prototype.

	Step Up DC-DC Converter for Automotive Application By Alexander ISURIN	[View] [Download]
Abstract: Electrification of vehicle accessories often requires the application of low voltage high current step up DC-DC converter with a high voltage gain ratio qualified for use in an automotive environment. The proposed topology provides step-up on low voltage side that reduces the transformer turns ratio, leading to a simplified transformer design with reduced cost and increased efficiency which is especially important with low input voltage (10-20VDC) at 2-4kW or more. Fundamental operation of the topology has been and verified by simulation in NL-5. An experimental prototype has been built, which verifies the performance and high efficiency of the circuit topology. High efficiency DC-DC (94\%, 3kW and 94.5\%, 10kW) prototypes have been built. This topology is a better solution for higher power at low input voltage than parallel input stages. It was compared with other topologies by cost and performance.