Detection of Series Arcs in Low-Voltage AC Power Lines Using Load Side Voltage Sag and Waveform Similarity Comparison

The similarity between arc fault current waveforms and nonlinear load currents can lead to misjudgments in arc fault identification methods that rely on arc current. In response to this issue, this paper establishes a unified fault criterion based on the conclusion that different types of loads that exhibit similar magnitudes of load side voltage sag during arc faults. Combined the voltage sag criterion with waveform criteria, this paper proposes a novel arc fault detection method. The method takes the load side voltage sag value exceeding the threshold as the detection start condition. After detection starts, the method identifies faults by calculating the degree of load side voltage waveform distortion using Hausdorff distance algorithm. Simulations are conducted on five different loads to determine the startup threshold and detection threshold. Test results show that the fault identification accuracy of the proposed method is 100% under the above thresholds.