A phase selector for transmission line protective relaying using the multi-parameter comparison criterion

A novel phase selector is proposed based on the multi-parameter comparison of fault components. Each of three phases is used as the reference phase in turn to calculate the positive sequence component and the sum of the zero and negative sequence components. The phase difference between the positive sequence component and the sum of the zero and negative sequence components is calculated under three different reference phases. Therefore, a multi-parameter criterion is proposed based on the three cosine values to accomplish the phase selection. The proposed method has an obvious boundary for faulty phase discrimination. Furthermore, the proposed method has good performance of sensitivity and reliability, and its effectiveness is verified by the simulations.