A method for judging small current grounding based on low-pass filtering

In the current algorithms for determining small current grounding, due to the complex on-site environment, the digital sampling waveforms may have glitches, which can affect the normal determination of small current grounding. To filter out the glitches in the digital sampling waveform, low-pass filtering was adopted to process the digital sampling waveform, and the filtered waveform was used for small current grounding judgment. Taking the single-phase grounding fault detection waveform of the distribution network with small current grounding as an example, the application mode and treatment effect of this method are elaborated in detail. The results show the feasibility and effectiveness of the method. Low-pass filtering can effectively remove the glitches in the sampled signal waveform without adversely affecting the effective information of the waveform, and it has a beneficial impact on the judgment of small current grounding.