ABSTRACT
Single-phase leakage fault is one of the most common line faults in coal mine power supply system. It will easily cause grade-skip trip because the switch in upper substation don’t have enough wait time. So when there is single-phase leakage fault happened in the coal mine grid, the switch of fault line and that in upper level substation will both trip, which leads to gradeskip trip. While with the application of WAMS (wide area measurement system) in coal mine grid, the control center will judge the fault line according to all the information in the grid, and send trip instruction only to fault switch. The biggest advantages of WAMS are data sampling synchronously in whole grid and decisions made by all the information received in control center.
