Research on compound protection for mine power network based on information fusion

Abstract：A complex protection scheme for power distribution line based on information fusion of power current and fault transient current was presented. In this scheme, band pass filters were connected at boundaries of protected zones in parallel. Due to the attenuation of transient component of fault current at frequency pass-band of the device, the difference of transient current spectrum energy in the frequency band between internal faults and external faults was strengthened. The results of PSCAD / EMTDC simulation prove the obvious difference, and protection setting value can be chosen based on the results of simulation. For reducing the loss of information caused by "Discount Rule", the bas- ic belief assignments of transient current and power current were set up by full subset reference vector method. Two ev- idences were fused by the D-S evidence combination theory, and a decision-making method based on the basic belief assignment was used to discriminate the internal faults. The simulation results prove that the scheme is an available mine 6/10 kV distribution line protection solution, which can not only discriminate internal faults or external faults, but also can ensure protection reliability under lighting strike or switch operating.