Influence of Humidity on Partial Discharge Characteristics of Cable Buffer Layer under Different Electric Fields

In recent years, the discharge problems in buffer layer have drawn wide attention in the industry. Relative humidity is an important impact factor of partial discharge, and it is necessary to carry out research on the mechanism of relative humidity on partial discharge characteristics. Based on the cable buffer layer structure, the partial discharge test platform based on the pulse-current method for buffer layer was established within a controllable humidity environment. The results show that the variation of relative humidity has no effects on the geometric shape of the partial discharge pattern, but it will affect the characteristic parameters of partial discharge. Under the lower humidity conditions, the discharge amplitude gradually decreases with the increase of relative humidity. Under the higher humidity conditions, the rise of relative humidity will promote the development of discharge activities in the buffer layer, and the discharge amplitude will increase with the increase of relative humidity.