An integral equation expression for steady state PD characteristics under sinusoidal wave voltage

This paper proposes an integral equation to describe the stochastic fluctuation of partial discharge (PD) occurrence under sinusoidal wave voltage based on a simple PD model (an equivalent circuit model). The stochastic behavior of PD fluctuation is assumed to arise from the fluctuation of PD delay time after the discharge inception voltage is built up across a discharge gap. For simplicity of calculation, the distribution of the delay time is assumed to obey an exponential distribution. Based on these assumptions, it is found that the proposed integral equation can provide the basic characteristics such as the PD pulse frequency distribution versus the applied voltage phase angle