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Development of Low-voltage Seamless Transfer Microgrid on Grid-connected Type Islands by Autonomous Operation

자율운전에 의한 계통연계형 도서의 저압 무순단 마이크로그리드 구축

  • Kim, Jeong Hun (Korea Electric Power Corporation (KEPCO) Research Institute) ;
  • Kwon, Jung-Min (Department of Electrical Engineering, Hanbat National University) ;
  • Yun, Sang-Yun (Korea Electric Power Corporation (KEPCO) Research Institute)
  • Received : 2017.09.18
  • Accepted : 2017.10.10
  • Published : 2017.12.01

Abstract

This paper presents research on low-voltage microgrids to maintain a continuous power supply to critical loads on grid-connected islands in Korea. The low-voltage microgrids of this paper focused on that changes public office buildings into uninterrupted microgrids by autonomous operation. For this, a microgrid controller (MGC) and a power conditioning system (PCS) that allow a seamless transfer between grid-connected and grid-isolated operation are proposed. The proposed PCS operates with a silicon controlled rectifier (SCR) switch and employs a simple structure. It supplies power continuously without operators through a coordinated operation between MGC and PCS. In addition, proposed MG has a schedule operation for minimizing electricity charges and provides ancillary services that enable the utilization of resources according to the operation purpose of utility distribution networks. To demonstrate the uninterrupted low-voltage microgrid proposed in this study, a microgrid was implemented and tested in a public office building in Anjwa Island, Jeollanam-do in Korea. A seamless, autonomous operation history, despite system disturbances, was obtained through a long-term demonstration of operation. The results showed that the proposed microgrid technology can be used to achieve energy resilience in grid-connected island areas.

Keywords

References

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