Prediction and Measurement of Induction Phenomena in the 765 kV Double Circuit Transmission Line operated with two voltage grades

765 kV 송전선로에서의 이종 전압등급 병행 운전시의 유도현상 예측 및 실측 결과

The western route of KEPCO's 765 kV transmission line has been tentatively operating as 345 kV voltage before commercial operation. KEPCO decided to operate the 765 kV line for commercial operation after completing the test operation of 765 kV substation in 2002. In the process of energizing the line as 765 kV voltage, double circuit transmission line will be operated with two voltage grades of 765 kV and 345 kV. As the earthing switches are installed on both ends of the line, electrostatic induction voltage and electromagnetic induction current were calculated prior to the line energizing in order to confirm the ratings. The induced voltage and current are important for the maintenance of the parallel circuit. This paper presents the simulation results of electrical phenomena such as electrostatic induction voltage and electromagnetic induction current from the parallel line. The transmission line was modeled by EMTP (Electro-Magnetic Transient Program). The simulation results were compared with the measured results at the field.