Influence of temperature on electrical aging characteristics of polytetrafluoroethylene under nanosecond pulses

Polytetrafluoroethylene (PTFE) has been widely used in insulation equipment and high voltage apparatus due to its excellent insulating property. However, electrical aging phenomenon of PTFE may cause insulation failure under nanosecond pulses. Temperature is an important parameter that influences the electrical aging process. This paper investigated the effect of temperature on the electrical aging characteristics of PTFE under nanosecond pulses. A nanosecond pulse generator MPC50D based on magnetic pulse compression was used. The output voltage has a rise time of 30 ns and a full width at half maximum of 70 ns. The needle electrode was adopted to accelerate the aging process. The testing chamber SP-80U was used to control the temperature and humidity. The experimental results showed that the inception voltage increased and the speed of the aging process decreased when the temperature decreased. The effects of the pulse repetition rate and the impacting mechanism of temperature on electrical aging characteristics were also discussed.