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A Study on the Over Current Relay Misoperation in Power System with Distributed Generations

분산전원 연계 계통에서의 과전류계전기 오동작에 관한 연구

  • Park, Jong-Il ;
  • Lee, Kyebyung ;
  • Park, Chang-Hyun
  • 박종일 ;
  • 이계병 ;
  • 박창현
  • Received : 2018.10.26
  • Accepted : 2018.11.23
  • Published : 2018.12.01

Abstract

This paper deals with an analysis of the causes of over current relay(OCR) misoperation in power system with distributed generations(DG). In general, Y-D and Y-Y-D transformer connections are used for grid interconnection of DG. According to the interconnection guideline, the neutral point on Y side should be grounded. However, these transformer connections can lead to OCR misoperation as well as over current ground relay(OCGR) misoperation. Several researches have addressed the OCGR misoperation due to the interaction between transformer connections and zero-sequence voltage of distribution system. Recently, a misoperation of OCR at the point of DG interconnection to the utility system has been also reported. With increasing the interconnections of DG, such OCR as well as OCGR misoperations are expected to increase. In this paper, PSCAD/EMTDC modeling including DG interconnection transformer was performed and various case studies was carried out for identifying the cause of OCR misoperation.

Keywords

Over current ground relay(OCGR);Over current relay(OCR);Voltage unbalance;Yg-Yg-D transformer;Zero-sequence harmonic

References

  1. Jong-Gyeoum Kim, Young-Jeen Park, "The Measurement & Analysis of Voltage Unbalance Factor at LV Customer of Three-Phase Four-Wire System", Journal of the Korean Institute of Illuminating and Electrical Installation Engineers, Vol. 18, No. 6, pp. 91-99, Nov. 2004. https://doi.org/10.5207/JIEIE.2004.18.6.091
  2. Jung-Eun Lee, Young-Joo Song, Hong-Kyoo Choi, Tae-Hoon Kim, In-Tae Kim, "A Study on Application for Y-Tz Transformer Winding Method to Decrease the Current Unbalance on the Source Side", The Transactions of The Korean Institute of Electrical Engineers, Vol. 63, No. 9, pp. 1206-1211, Jul. 2014. https://doi.org/10.5370/KIEE.2014.63.9.1206
  3. Jong-Gyeum Kim, "A New Analysis for Load Unbalance Factor", The Transactions of the Korean Institute of Electrical Engineers P, Vol. 55, No. 2, pp. 67-72, Jun. 2006.
  4. Korea Electric Association, "Consumer's Electrical Installation Guide", 2016.
  5. Dong-Yeol Shin, Bok-Nam Ha, Won-Wook Jung, Han-Ju Cha, "A Study on the Reverse-Power-Flow Phenomenon due to Transformer Wiring Types in Distribution System", Journal of the Korean Institute of Illuminating and Electrical Installation Engineers, Vol. 22, No. 09, pp. 111-119, 2008.
  6. Dong-Yeol Shin, Yong-woo Park, Han-Ju Cha, "A Case Study on Malfunction of OCGR and Inaccuracy of Watt-hour Meter in Distributed Generation System", The Transactions of The Korean Institute of Electrical Engineer, Vol. 57, No. 08, 2008.
  7. Arthur R. Bergen, Vijay Vittal, Power Systems Analysis, 2nd Edition, Prentice-Hall, pp. 470-472, 2000.
  8. Aeso International Inc, "Transformer Modelling Guide," Jul. 08, 2014.

Acknowledgement

Supported by : 한국전력공사