EPE Association: EPE 2014 - LS1a: Advanced Power Converter Topologies

EPE 2014 - LS1a: Advanced Power Converter Topologies
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2014 ECCE Europe - Conference > EPE 2014 - Topic 02: Power Converter Topologies and Design > EPE 2014 - LS1a: Advanced Power Converter Topologies

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   A Hybrid Converter for Medium Voltage using a Low-Voltage Current Source Active Filter Connected via a Series Capacitor
By Savvas PAPADOPOULOS, Mohamed RASHED, Christian KLUMPNER, Patrick WHEELER [View]
[Download]

Abstract: This paper proposes a new three phase hybrid inverter topology suitable for medium to high voltage inverter applications. The topology consists of a 3-phase VSI rated at medium voltage acting as a main inverter bridge processing the bulk power whilst being connected in parallel to a CSI acting as an active filter to cancel out the switching current ripple produced by the VSI. The CSI is connected via a series capacitor which minimises the voltage stress to only a small fraction of the fundamental grid voltage via a control approach shown in the paper. Therefore, the added installed power of the CSI is less than 4\% of the main inverter bridge which should account for a small added cost. As a result, the hybrid topology allows for optimal device utilization to achieve high output current quality with minimal device ratings and potentially improved efficiency. The control of the CSI is independent to the main inverter bridge which means that the auxiliary converter solution can be retrofitted to existing medium voltage installations for power quality improvement.

   A Novel Scheme for a Bi-directional Isolated DC-DC Converter with a DC-link Diode Using Reverse Recovery Current
By Takae SHIMADA, Hiroyuki SHOJI, kimiaki TANIGUCHI [View]
[Download]

Abstract: A bi-directional isolated DC-DC converter using a novel circuit topology and its control method are described. The proposed circuit is based on a voltage-fed full-bridge circuit on the high-voltage side and a current-fed full-bridge circuit with an active clamp circuit on the low-voltage side. In order to make use of only MOSFETs with slow body diodes in the high-voltage full-bridge circuit to reduce the switching loss, the high-voltage side has a newly added DC-link fast recovery diode. The proposed control method, reverse recovery commutation and acceleration, recovers the reverse recovery current of the DC-link diode and stores the current in Lr, and accelerates the current for smooth boost operation so that the voltage applied to the low-voltage side MOSFETs is kept down. All nine MOSFETs can be turned on under zero-voltage switching conditions in both buck and boost modes. The results of testing under minimum input voltage conditions demonstrated that the proposed method increases the maximum output power without increasing the voltage applied to the low-voltage side MOSFETs. A 1.5-kW prototype exhibited efficiency of 94 \% at maximum output power at a switching frequency of 100 kHz.

   Cell Capacitor Sizing in Modular Multilevel Converters and Hybrid Topologies
By Michael MERLIN, Timothy GREEN, Paul MITCHESON, FRANCISCO JOSE MORENO, Kevin DYKE, David TRAINER [View]
[Download]

Abstract: This paper presents a method to calculate the minimal size of cell capacitors in multilevel VSCs which meets a maximum voltage deviation criterion under ideal conditions. This method is applied to the Modular Multilevel Converter (MMC), the Alternate Arm Converter (AAC) and the hybrid multilevel converter with ac-side cascaded H-bridge cells (AC-CHB). The results show that the newer VSC topologies exhibits smaller energy deviation in their stacks, leading to an overall smaller volume of cell capacitors for the converter station but often accompanied by some compromises such as higher power losses or degraded DC current waveform quality.

   Ensuring Soft-Switching Operation of a Three-Phase Dual-Active Bridge DC-DC Converter applying an Auxiliary Resonant-Commutated Pole
By Nils SOLTAU, Julian LANGE, Marco STIENEKER, Hanno STAGGE, Rik DE DONCKER [View]
[Download]

Abstract: An auxiliary resonant-commutated pole (ARCP) ensures soft switching in the entire operation range of a three-phase dual-active bridge dc-dc converter. This work evaluates the design and the resulting boost in system efficiency for different semiconductor materials and devices. Afterwards, a full-scale medium-voltage prototype of an ARCP is constructed. The subsequent measurements are presented within this work, before the economic feasibility is discussed.

EPE 2014 - LS1a: Advanced Power Converter Topologies
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2014 ECCE Europe - Conference > EPE 2014 - Topic 02: Power Converter Topologies and Design > EPE 2014 - LS1a: Advanced Power Converter Topologies
	[return to parent folder]

	A Hybrid Converter for Medium Voltage using a Low-Voltage Current Source Active Filter Connected via a Series Capacitor By Savvas PAPADOPOULOS, Mohamed RASHED, Christian KLUMPNER, Patrick WHEELER	[View] [Download]
Abstract: This paper proposes a new three phase hybrid inverter topology suitable for medium to high voltage inverter applications. The topology consists of a 3-phase VSI rated at medium voltage acting as a main inverter bridge processing the bulk power whilst being connected in parallel to a CSI acting as an active filter to cancel out the switching current ripple produced by the VSI. The CSI is connected via a series capacitor which minimises the voltage stress to only a small fraction of the fundamental grid voltage via a control approach shown in the paper. Therefore, the added installed power of the CSI is less than 4\% of the main inverter bridge which should account for a small added cost. As a result, the hybrid topology allows for optimal device utilization to achieve high output current quality with minimal device ratings and potentially improved efficiency. The control of the CSI is independent to the main inverter bridge which means that the auxiliary converter solution can be retrofitted to existing medium voltage installations for power quality improvement.

	A Novel Scheme for a Bi-directional Isolated DC-DC Converter with a DC-link Diode Using Reverse Recovery Current By Takae SHIMADA, Hiroyuki SHOJI, kimiaki TANIGUCHI	[View] [Download]
Abstract: A bi-directional isolated DC-DC converter using a novel circuit topology and its control method are described. The proposed circuit is based on a voltage-fed full-bridge circuit on the high-voltage side and a current-fed full-bridge circuit with an active clamp circuit on the low-voltage side. In order to make use of only MOSFETs with slow body diodes in the high-voltage full-bridge circuit to reduce the switching loss, the high-voltage side has a newly added DC-link fast recovery diode. The proposed control method, reverse recovery commutation and acceleration, recovers the reverse recovery current of the DC-link diode and stores the current in Lr, and accelerates the current for smooth boost operation so that the voltage applied to the low-voltage side MOSFETs is kept down. All nine MOSFETs can be turned on under zero-voltage switching conditions in both buck and boost modes. The results of testing under minimum input voltage conditions demonstrated that the proposed method increases the maximum output power without increasing the voltage applied to the low-voltage side MOSFETs. A 1.5-kW prototype exhibited efficiency of 94 \% at maximum output power at a switching frequency of 100 kHz.

	Cell Capacitor Sizing in Modular Multilevel Converters and Hybrid Topologies By Michael MERLIN, Timothy GREEN, Paul MITCHESON, FRANCISCO JOSE MORENO, Kevin DYKE, David TRAINER	[View] [Download]
Abstract: This paper presents a method to calculate the minimal size of cell capacitors in multilevel VSCs which meets a maximum voltage deviation criterion under ideal conditions. This method is applied to the Modular Multilevel Converter (MMC), the Alternate Arm Converter (AAC) and the hybrid multilevel converter with ac-side cascaded H-bridge cells (AC-CHB). The results show that the newer VSC topologies exhibits smaller energy deviation in their stacks, leading to an overall smaller volume of cell capacitors for the converter station but often accompanied by some compromises such as higher power losses or degraded DC current waveform quality.

	Ensuring Soft-Switching Operation of a Three-Phase Dual-Active Bridge DC-DC Converter applying an Auxiliary Resonant-Commutated Pole By Nils SOLTAU, Julian LANGE, Marco STIENEKER, Hanno STAGGE, Rik DE DONCKER	[View] [Download]
Abstract: An auxiliary resonant-commutated pole (ARCP) ensures soft switching in the entire operation range of a three-phase dual-active bridge dc-dc converter. This work evaluates the design and the resulting boost in system efficiency for different semiconductor materials and devices. Afterwards, a full-scale medium-voltage prototype of an ARCP is constructed. The subsequent measurements are presented within this work, before the economic feasibility is discussed.