Fuzzy approach to fault classification for transmission line protection

This paper presents a scheme for real time fault location and classification on transmission lines using fuzzy logic technique. The protection algorithm is based on the travelling waves present on major transmission lines after the incidence of a fault. The time interval between the initial travelling wave propagated from a fault and a later wave resulting from a reflection at the fault position is used to find the location of the fault. A possible application based on modal analysis to detect the type of fault is also proposed. This paper shows that a fuzzy approach can be useful in transmission line protection, whenever fuzzy decisions have to be undertaken. Simulation results are used to illustrate the basic features of the performance of the new scheme on a 220 kV transmission line.