Electrical aging models for fine gauge magnet wire enamel of flyback transformer

This paper presents the results of accelerated aging tests conducted on electrical insulation of fine gauge magnet wire used in high voltage coils of an encapsulated flyback transformer. The aim of this work is to find an empirical aging model to estimate the lifetime of the insulation exposed to high frequency pulse voltages. Both the inverse power law and exponential models were examined. The lifetime model was obtained by combining the Weibull distribution of failure data with the proposed aging model. The arbitrary parameters of the combined Weibull-lifetime-stress model were obtained using maximum likelihood estimation. The aging results show that failure data at pulse voltage can be represented by both the inverse power law and exponential models.