The Influences of Humidity on PD Characteristics in a Void in Polyvinyl Chloride (PVC)

Partial Discharges (PD's) may cause the degradation of insulating materials and affects the lifetime of high-voltage apparatuses. Therefore, it is important to understand the correlation between PD behaviors and the aging process. This paper reports the experimental results on partial discharges in a void in Polyvinyl Chloride (PVC). The PD's in PVC were measured using CIGRE method II electrode system. The PD patterns (phi-q-n), the maximum charge (Q_max), PD pulse number (n) and other characteristics were investigated. The PD (phi-q-n) patterns and characteristics changed remarkably with time and were compared to each other. The experimental results showed that the PD patterns and PD characteristics were affected by aging and humidity condition