Voltage Control of ULTC and Distributed Generations in Distribution System

분산전원이 연계된 배전계통에서 ULTC와 분산전원의 전압제어

  • Received : 2011.10.21
  • Accepted : 2011.11.24
  • Published : 2011.12.01


LDC(Line Drop Compensation) is widely used in controlling ULTC(Under Load Tap Changer) output voltage at distribution substation. However, LDC may experience some difficulties in voltage control due to renewable energy resources and distributed generations. Therefore, more advanced voltage control algorithm is necessary to deal with these problems. In this paper, a modified voltage control algorithm for ULTC and DG is suggested. ULTC is operated with the voltages measured at various points in distribution system and prevents overvoltage and undervoltage in the distribution feeders. Reactive power controller in DG compensates the voltage drop in each distribution feeders. By these algorithms, the voltage unbalance between feeders and voltage limit violation will be reduced and the voltage profile in each feeder will become more flat.


Under load tap changer(ULTC);Distribted generation(DG);Distribution system;Line drop compensation(LDC);Reactive power;Voltage control


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Supported by : 한국에너지 기술평가원(KETEP)