Automatic Differential Protection of Distribution Network Line Current Based on DTW Algorithm and Phase Features

Aiming at the inefficiency of traditional protection systems in distribution network line faults, a distribution network line current automatic differential protection method based on DTW algorithm and phase characteristics is proposed. Firstly, a device framework integrating data acquisition, digital processing, and protection algorithms was designed to achieve precise processing and discrimination of fault currents and voltages. In terms of fault detection mechanism, differential protection criterion is introduced, which extracts current amplitude and phase characteristics, and uses line fault direction diagram to accurately locate the fault location and evaluate its severity. Innovatively applying the DTW algorithm allows for adaptive adjustment of the timeline length based on data features, thereby optimizing the similarity between data collection points and significantly improving the accuracy of fault feature recognition. By using the DTW distance as the objective function, this method can accurately calculate the position of short-circuit points, grounding resistance value, and fault phase current amplitude, effectively improving the reliability and efficiency of distribution network line protection. The simulation results have verified the improved protection effect of this method in terms of amplitude and phase difference, demonstrating the characteristics of rapid response and efficient action. Even in the case of frequent faults, its efficient performance can still be maintained.