Research on Centralized Short-Circuit and Leakage Protection for High-Voltage System of Underground Central Substation

According to the problems which are relay protection is difficult to adjust and when line fault occurs it will easily get override trip in the underground 6 kV power supply system in Gu Shu-yuan Coal Mine. This paper presents a centralized selective short circuit and leakage protection system. Which focuses on the analysis of the short circuit longitudinal differential protection, based on pattern recognition method of single-phase earth leakage protection principle, and completes the rapidity and selectivity of the leakage fault line selection . Through the simulation, experimental and field operation shows that the schemes can effectively improve the reliability and safety of high voltage power supply system in Gu Shu-yuan Coal Mine ,it also establishes the necessary foundation of the goal of "network relay protection" in high voltage power supply system for in China.