국내 교류 전기철도 급전계통 보호용 과전류 계전기 모델링 및 과부하 보호 협조에 관한 연구

In this paper, modeling of overcurrent relay(OCR) to protect domestic AC electric railway Auto Transformer(AT) feeding system and operation characteristic analysis on overload condition are described. The target system of this paper is actual site where overload trip of circuit breaker occurs frequently. Because this AT feeding system is made of parallel single track which had a load(electric train) respectively, and is connected with only T phase of Scott Transformer. In addition, this system has been feeding 66kV voltage by KEPCO, not 154kV. We focus on protective coordination of Scott Transformer primary side and secondary side OCR for Korea single track AC electrical railway system in operation currently. We modeled single track AT feeding system and OCR. Also we performed faults and overload analysis for verification of OCR"s setting values and system modeling. To analyze above mentioned research, we used PSCAD/EMTDC software tool.