Effect of Temperature on Partial Discharge Characteristics of BOPP Film Under Nanosecond Pulse Voltage

Temperature is an important factor to aggravate the insulation degradation of metallized film capacitors, in order to study the effect of temperature on the partial discharge characteristics of biaxially oriented polypropylene (BOPP) film under nanosecond pulse voltage, the partial discharge measurement of BOPP film was carried out at varying temperatures (25 °C~100 °C) and with different rising times (15~115 ns). It is found that the repetitive partial discharge inception voltage (RPDIV) and partial discharge time-lag gradually decrease with the increase of temperature, while the number of partial discharges and the amplitude of discharges in the falling stage of the pulse show a monotonically increasing trend; the amplitude of discharges in the rising stage of the pulse increases, then decreases and then increases again with the increase of temperature, and there are the local maximum and local minimum at 55°C and 85°C, respectively. Meanwhile, based on the thermal field emission effect, the quantitative mathematical relationship between the partial discharge statistical characteristics and temperature is established for the first time. The results are expected to provide experimental basis and mechanism explanation for the reliability assessment and insulation performance improvement of dielectric insulation for energy storage under extreme conditions.