Earth Fault Detection Method in Non-solidly Earthed Network Based on the Increments of Phase Current

In current distribution network, transient features of current and voltage are widely used to solve earth fault as ground system varies and makes it is very important to find its precise fault point when an earth fault occurs. Zero-sequence current and voltage are required to acquire in most method, which is not suitable for old distribution line. This thesis comes up with a method which uses abrupt current change to trigger its logic, determine fault point according to Bhattacharyya Distance and calculate unbalance ratio via the fault point and complete the whole procedure. This method is very precise and robust according to simulation analysis and real-time experiment results.