Power system fault detection and state estimation using Kalman filter with hypothesis testing

An algorithm for detecting power system faults and estimating the pre and post-fault steady state values of the voltages and currents is described. The proposed algorithm is based on the Kalman filter and hypothesis testing. It is shown that a power system fault is ideally suited for single sample hypothesis testing. The performance of the proposed technique is examined in connection with the protection of parallel transmission lines. The proposed technique avoids many problems of parallel line protection. The simplicity and the avoidance of complicated software and hardware in addition to the stability of the relay under different switching conditions are some of the features of the proposed technique. Studies performed on a long double-circuit transmission line with and without series compensation show a trip time in all cases of around 5 ms