EPE Association: EPE 2018 - LS2b: High Power Converters

EPE 2018 - LS2b: High Power Converters
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2018 ECCE Europe - Conference > EPE 2018 - Topic 02: Power Converter Topologies and Design > EPE 2018 - LS2b: High Power Converters

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   A Dual Active Bridge Topology with Increased Voltage Conversion Range
By Martin WATTENBERG [View]
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Abstract: We present a dual active bridge topology suitable for wide voltage range applications covering all combinations of 200V to 600V on the input and 20V to 60V on the output with constant power of 1kW. We employ a stepped inductance scheme to adjust the effective inductance of the converter, thus extending the efficient operation range. Using a variable switching frequency between 35 kHz and 150 kHz with operation-point-dependent limits further increases the performance of the converter. A prototype was built and the proposed changes have been compared to a fixed frequency, fixed inductance implementation. Measurements show a maximum loss reduction of 40 \%, leading to a peak efficiency of 97\% whilemaintaining constant output power over the entire working area.

   Design and Commissioning of a 10 kV Three-Phase Transformerless Inverter with 15 kV Silicon Carbide MOSFETs
By Jürgen THOMA [View]
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Abstract: A medium voltage inverter based on 15 kV Silicon Carbide (SiC) MOSFETs is presented in thispaper. By using a three-level topology it is possible to feed directly into a 10 kVAC distribution grid.Measurement results of the successful operation at full output voltage are shown. A maximumefficiency of over 97\% is reached.

   Design of a High Frequency 3-phase 3-level Hybrid Active-NPC Inverter
By Alireza KOUCHAKI [View]
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Abstract: This paper presents design and implementation of a three-level hybrid active neutral point clamped (3LANPC) inverter using Gallium-Nitride (GaN) switches. This paper shows a modest usage of wide band gap (WBG) devices for achieving a high frequency converter. The ANPC benefits from hybrid modulation in which only two switches out of 6 active switches are modulating with high frequency (HF, carrier frequency) and the rest are switching with the reference frequency or low frequency (LF). Therefore, WBG switches can be utilized for these two HF switches. In this paper, gallium-nitride (GaN) FETs have been used for the HF switches. Two different switch technologies plus two different modulation schemes have introduced a hybrid 3L-ANPC. The semiconductor losses are calculated and modified with respect to the switch technologies. A three-phase 10kW hybrid 3L-ANPC is designed using two 650V GaN-FETs and four 650V Si-MOSFETs for each phase. The switching frequency of the GaN-FETs is optimized to be at 100 kHz. Different modulation schemes are implemented in the FPGA of a dSPACE device and the converter is tested at various conditions.

   Electronic Capacitor Realization for Grid-Connected Power Converters
By Alon KUPERMAN [View]
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Abstract: The paper suggests a way of operating a DC-DC converter to directly emulate a large capacitance of a controllable value when a much smaller capacitor is actually utilized. Converters that are operated in this way are referred to as Electronic Capacitors (EC). The proposed system has the potential of replacing in a plug-and-play fashion any real large capacitor (within the control bandwidth). The control algorithm forces the converter terminal voltage to follow capacitance equation as a function of sensed (or estimated) terminal current while simultaneously compensating for conversion losses. The proposed method is verified by emulating bulk DC link capacitance of a commercial power factor correction (PFC) front end. It is shown that steady state performance of the system with electrolytic and electronic capacitors is nearly the same at both DC link and grid sides. On the other hand, transients are handled slightly differently due to dissimilar hold-up abilities of real and electronic capacitors and are therefore subject of future research.

EPE 2018 - LS2b: High Power Converters
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2018 ECCE Europe - Conference > EPE 2018 - Topic 02: Power Converter Topologies and Design > EPE 2018 - LS2b: High Power Converters
	[return to parent folder]

	A Dual Active Bridge Topology with Increased Voltage Conversion Range By Martin WATTENBERG	[View] [Download]
Abstract: We present a dual active bridge topology suitable for wide voltage range applications covering all combinations of 200V to 600V on the input and 20V to 60V on the output with constant power of 1kW. We employ a stepped inductance scheme to adjust the effective inductance of the converter, thus extending the efficient operation range. Using a variable switching frequency between 35 kHz and 150 kHz with operation-point-dependent limits further increases the performance of the converter. A prototype was built and the proposed changes have been compared to a fixed frequency, fixed inductance implementation. Measurements show a maximum loss reduction of 40 \%, leading to a peak efficiency of 97\% whilemaintaining constant output power over the entire working area.

	Design and Commissioning of a 10 kV Three-Phase Transformerless Inverter with 15 kV Silicon Carbide MOSFETs By Jürgen THOMA	[View] [Download]
Abstract: A medium voltage inverter based on 15 kV Silicon Carbide (SiC) MOSFETs is presented in thispaper. By using a three-level topology it is possible to feed directly into a 10 kVAC distribution grid.Measurement results of the successful operation at full output voltage are shown. A maximumefficiency of over 97\% is reached.

	Design of a High Frequency 3-phase 3-level Hybrid Active-NPC Inverter By Alireza KOUCHAKI	[View] [Download]
Abstract: This paper presents design and implementation of a three-level hybrid active neutral point clamped (3LANPC) inverter using Gallium-Nitride (GaN) switches. This paper shows a modest usage of wide band gap (WBG) devices for achieving a high frequency converter. The ANPC benefits from hybrid modulation in which only two switches out of 6 active switches are modulating with high frequency (HF, carrier frequency) and the rest are switching with the reference frequency or low frequency (LF). Therefore, WBG switches can be utilized for these two HF switches. In this paper, gallium-nitride (GaN) FETs have been used for the HF switches. Two different switch technologies plus two different modulation schemes have introduced a hybrid 3L-ANPC. The semiconductor losses are calculated and modified with respect to the switch technologies. A three-phase 10kW hybrid 3L-ANPC is designed using two 650V GaN-FETs and four 650V Si-MOSFETs for each phase. The switching frequency of the GaN-FETs is optimized to be at 100 kHz. Different modulation schemes are implemented in the FPGA of a dSPACE device and the converter is tested at various conditions.

	Electronic Capacitor Realization for Grid-Connected Power Converters By Alon KUPERMAN	[View] [Download]
Abstract: The paper suggests a way of operating a DC-DC converter to directly emulate a large capacitance of a controllable value when a much smaller capacitor is actually utilized. Converters that are operated in this way are referred to as Electronic Capacitors (EC). The proposed system has the potential of replacing in a plug-and-play fashion any real large capacitor (within the control bandwidth). The control algorithm forces the converter terminal voltage to follow capacitance equation as a function of sensed (or estimated) terminal current while simultaneously compensating for conversion losses. The proposed method is verified by emulating bulk DC link capacitance of a commercial power factor correction (PFC) front end. It is shown that steady state performance of the system with electrolytic and electronic capacitors is nearly the same at both DC link and grid sides. On the other hand, transients are handled slightly differently due to dissimilar hold-up abilities of real and electronic capacitors and are therefore subject of future research.