Voltage Dynamic Response Analysis Under the Fault of Distribution Network

After the grounding high-impedance fault occurs in the distribution network, the fault current is weak, and the traditional protection cannot effectively identify and remove the fault in time. Therefore, in the event of a distribution network line fault, a fast and reliable fault location method is required to achieve accurate fault point location. Over recent decades, Travelling Wave (TW)-based fault location techniques have gained significant traction. However, prevailing TW methods entail excessive computational resource utilization within the signal processing algorithm for wave head extraction, prompting the need for a novel approach characterized by rapid response times and heightened positional precision. This study introduces a TW wave head identification algorithm leveraging a high-pass filter for seamless extraction of the wave head by filtering out low-frequency signal fluctuations. Furthermore, to enhance precision in fault localization, a double-ended methodology is employed for precise fault determination. In this paper, the theoretical design of the method is introduced in detail, and the effectiveness of the method is tested on the simulation model of single-phase grounding fault of distribution line of neutral ungrounded system established in PSCAD, and the reliability of the method is fully revealed by comparing with the commonly used TW wave head extraction technologies based on wavelet transform and single-ended TW positioning method.