Multiple stress aging of magnet wire by high frequency voltage pulses and high temperatures

This paper presents the results of multistress accelerated aging tests conducted on electrical insulation of fine gauge magnet wire used in high voltage coils of encapsulated flyback transformers. The aim of this work is to find an empirical electrical-thermal model to estimate the lifetime of the insulation exposed to multistress conditions including voltage and temperature at different high pulsating frequencies. The lifetime model was obtained by combining the Weibull distribution of failure data with electrical-thermal multistress aging model. The arbitrary parameters of the combined Weibull-life-stress model were obtained by maximum likelihood estimation.