Frequency-Dependent Surface-Discharge Lifetime and PRPD Failure Signatures of Polyimide Insulation Under High-Frequency Sinusoidal Voltage
Polyimide (PI) film is a widely used insulation material in high-frequency power equipment, yet its frequency–lifetime relation and terminal discharge features have rarely been resolved together over a complete ageing trajectory. This paper reports three contributions. First, a condition-specific frequency–lifetime rel...