Research on weather condition of significant decline of air gap breakdown voltage

In Pearl River Delta and other Chinese developed regions, the atmospheric environment presents a new feature that is air pollution and haze happens more and more frequently. Under this condition, the characteristics of external insulation should be paid more attention. In this paper, automatic discharge monitoring systems are installed in Guangzhou, the representative city of Pearl River Delta, to monitor breakdown voltage of the air gap and atmospheric parameters. Analysis shows that there are a few discharges with a much lower breakdown voltage. The weather condition of significant decline of breakdown voltage (SDOBV) is studied in this paper. The research shows that SDOBV appears in spring frequently, and breakdown voltage will drop significantly in high humidity, low wind velocity and low illuminance environment.