Effect of high-frequency pulse ageing on dielectric response of paper/oil insulation

The presence of high-frequency components has been drastically increasing in the power network due to increased use of power electronics and non-linear loads. Such pulsed or high-frequency voltages may affect the performance of insulation systems by increasing their ageing speed. To evaluate accelerated ageing of dielectric materials under high-frequency pulses with different characteristics, it is required to have comparisons between parameters that can indicate the degradation level of aged dielectric materials. This research adopts dielectric spectroscopy applied over a wide range of frequency and measurement voltage, for such comparisons. Paper/oil samples are tested at different time intervals of ageing, under both unipolar and bipolar voltage applications, and the dielectric parameters are compared. The results of this study can contribute in understanding the basics of dielectric responses of paper/oil insulation under high-frequency transient conditions.