Background Noise of Partial Discharge Detection and Its Suppression in Complex Electromagnetic Environment

Partial Discharge (PD) signal generated by high-voltage electrical equipment is usually weak. Therefore, the small Electromagnetic Interference (EMI) is strict required in site when carrying out the PD test. Generally, the background noise of PD signal cannot exceed 2~3 pC. However, in the application scenario of power system PD field detection, we have to face the problem of the complex electromagnetic environment and excessive background noise, and there is few research document focus on it at present. In this paper, we study the background noise type, its mechanism and coupling path of PD detection through experiments in a complex electromagnetic environment. Through our constant attempts, several effective noise suppression methods such as improved grounding, power isolation and optimized wiring layout are proposed. As result, the original background noise is successfully reduced from 28~50 pC to 1.2~1.6 pC and meet the PD test requirements, which provides valuable experience for background noise suppression of partial discharge detection in complex electromagnetic environment.