Adaptive Differential Protection Method for Active Distribution Network Based on DTW Distance Algorithm

The access to a large number of distributed generation (DG) changes the structure of the distribution network and fault characteristics, and the traditional three-stage current protection makes it difficult to identify faults accurately. Therefore, a differential protection method for active distribution network (ADN) based on dynamic time warping (DTW) distance is proposed. Firstly, utilizing the DTW distance algorithm to calculate and normalize the current waveform similarity at both ends of the protected line. Then, according to the DTW distance calculation results, the adaptive braking coefficient of current differential protection is constructed to realize reliable fault identification. Finally, an ADN simulation model is built in PSCAD to verify the performance of the proposed method. The simulation results show that the DG access capacity does not affect the proposed method, which has higher sensitivity than traditional current differential protection and certain resistance to fault resistance, noise, and engineering applicability.