Journal of Power Electronics

The Korean Institute of Power Electronics (전력전자학회)
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Topology and start-up strategy for DC-DC transformers based on voltage balancing unit

  • Zhang, Jialin (C-EPRI Electric Power Engineering Co., Ltd., NARI Group Corporation) ;
  • Zha, Kunpeng (C-EPRI Electric Power Engineering Co., Ltd., NARI Group Corporation) ;
  • Tang, Xiaojun (School of Electrical Engineering, Xi'an Jiaotong University) ;
  • Yang, Yuefeng (C-EPRI Electric Power Engineering Co., Ltd., NARI Group Corporation) ;
  • Yan, Hui (C-EPRI Electric Power Engineering Co., Ltd., NARI Group Corporation) ;
  • Wen, Fuyue (C-EPRI Electric Power Engineering Co., Ltd., NARI Group Corporation) ;
  • Shi, Mingming (State Grid Jiangsu Electric Power Co., Ltd. Research Institute)
  • Received : 2020.12.08
  • Accepted : 2021.03.30
  • Published : 2021.07.20
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Abstract

As a core piece of equipment in DC distribution networks, DC solid-state transformers (DCSSTs) are attracting more and more attention in academia and industry. Due to the limitations in terms of the electrical stress of the switches, the input series output parallel (ISOP) structure is adopted in DCSSTs. This paper proposed an improved DCSST topology based on a voltage balancing unit (VBU). This topology has the advantages of higher power density, reduced weight, and cascaded number without compromising efficiency, cost, or reliability. The working modes, mathematical models, and control strategy are analyzed. In addition, a start-up strategy and a parameter design method are proposed in this paper. Simulation and experimental results verify the correctness and effectiveness of the proposed solution. The proposed DCSST is a practical scheme for the application of DC distribution networks.

Keywords

Acknowledgement

This study was financially supported by the State Grid Corporation of China Science and Technology Project: Research on the key technologies of high efficiency and compact multi-port DC transformer.

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