A novel pilot protection scheme for transmission lines based on current distribution histograms and their Bhattacharyya coefficient

Abstract The current waveform characteristics at both ends of a transmission line under different disturbances are represented by means of probability distribution histograms. By adopting the Bhattacharyya distance (BD) algorithm to quantify the similarity of current distribution histograms, a novel scheme of pilot protection for transmission lines based on Bhattacharyya coefficient (BC) is put forward. The proposed scheme can correctly identify internal faults, external faults, and faults accompanied with current transformer (CT) saturation of transmission lines. It also shows good performance in the cases of abnormal samples. The validity of the proposed scheme is evaluated by various simulation and dynamic analog experiment tests.