Optical Partial Discharge Detection and Analysis for Insulation Aging Evolution

Partial discharge (PD) is considered a typical sign in the early stage of insulation failure. However, PD characteristics under square wave voltage at different temperatures and air pressures have rarely been investigated. One of the challenges is the strong electromagnetic interference (EMI) to PD detection aroused by the rising/falling edge of the square wave. To address this issue, a silicon photomultiplier (SiPM) optical method is proposed to detect PD of twisted pair insulation. PD inception voltage (PDIV) is measured and the results show that the PDIV decreases with the increase in temperature and decrease in air pressure. Moreover, the aging experiments are conducted to explore the relationship between PD accumulation and the lifetime at various temperatures and air pressures. Finally, a lifetime model is proposed to evaluate the remaining lifetime of twisted pair insulation.