On the Use of Traveling Wave for Fault Location in Coal Mine Distribution Power Systems

Coal mine distribution power system is a one-terminal power network which located at the end side of power network. When single phase to ground fault occurs, fault current is too weak to locate the fault position. In order to solve this problem, a new algorithm is presented, which uses the difference of wave velocity between ground mode component and aerial mode component of traveling wave that arrives at the point of detection, the occurring time of modulus maxima of the wavelet can be considered as the arriving time of the ground mode component and aerial mode component of current traveling pulse. Only the time of initial wave head arriving is detected, and it is not affected by other branch lines, the dependability of the fault location is improved. Further more, the on-line measurement of traveling wave velocity is implemented, and it is effective for the improvement of fault location accuracy based on traveling wave. The simulation of the ideal condition and the existence of transitional resistance in the 6kv mine power network proved that this method is more effective and feasible.