On-site Partial Discharge Detection Using Pulse Current Method for Collective Capacitors

As an important reactive power compensation equipment in the substation, collective capacitors are of great significance to the safe and stable operation of the power grid. However, the large capacity of collective capacitors reduces the sensitivity of local discharge detection and increases the capacity requirements of the test equipment. This paper proposes a method of optimizing the design of detection impedance and suppressing loop interference, which can improve the sensitivity of partial discharge detection by pulsed current method and makes the minimum detectable discharge meet the test requirements. Through theoretical analysis and experimental research, the equivalence of partial discharge test under low frequency 5Hz and industrial frequency 50Hz is verified, and a low-frequency partial discharge on-site detection program is designed, which is successfully applied in the substation site. In this paper, the method reduces the capacity of the compensation reactor and the test power demand and realizes the partial discharge field detection of the aggregate capacitor.