Partial Discharge Characteristics of Biaxially Oriented Polypropylene Film Under Nanosecond Pulse Voltage With High Rise Rate

Film capacitors are used as the key energy storage device for high-power pulse generators, and partial discharge (PD) is an important factor leading to insulation degradation and the failure of film capacitors. To accurately evaluate the effect of the rise rate on PD under nanosecond pulse voltage, experiments on the PD characteristics of biaxially oriented polypropylene (BOPP) films under high rise rate (18.3–140 V/ns) nanosecond pulse voltages were carried out. The PDs were mostly concentrated in the rising and falling phases of the nanosecond pulse. Moreover, the repetitive PD inception voltage (RPDIV) first increased and then remained unchanged as the rise time increased, and the PD amplitude and the number of discharges in the rising phase of the nanosecond pulse increased as the rise rate increased, while the discharge time lag decreased gradually. The PD amplitude, the number of discharges, and the discharge time lag in the falling phase of the nanosecond pulse all increased as the rise rate increased. In addition, when the rise rate was less than 50 V/ns, the PD statistical characteristics changed rapidly as the rise rate increased, and when the rise rate was greater than 50 V/ns, the PD statistical characteristics gradually changed more slowly as the rise rate increased.