Differential protection of distribution lines based on Hausdorff algorithm

Abstract

Given the weak time synchronization capability of the feeder terminal unit (FTU) in the distribution network, a new differential protection method for the distribution network is proposed. The method uses the abrupt change of the phase current as the starting criterion, then sends a phase current sampling sequence of power frequency period to the associated FTU, and determines whether the fault occurs in the section by calculating the Hausdorff distance between the sample sequences of the associated FTU current. This algorithm needs no voltage information and the calculation amount is small, making it suitable for multi-branch lines and accurately identifying faults inside and outside the area. A large number of simulation experiments show that the protection scheme has a 4 ms anti-synchronization error capability and is basically unaffected by transition resistance, which is suitable for active distribution networks with high penetration of distributed power supply.