Study of Effects of Repetitive Impulse Voltage on Paper Insulation

Repetitive impulses have become an inherent part of the present power system due to various conditions discussed. Stress due to repetitive pulses on insulator has a detrimental effect and may cause system failures in unfavorable conditions. In this study, various paper insulators used in transformer and motor were tested using recurrent impulse voltages. Breakdown voltages were noted and a design scheme was employed to capture the PD before breakdown using a HFCT and PC oscilloscope. A comparative analysis was done based on its breakdown and on its partial discharge data. DWT and reconstruction was performed on the PD signal and analysed to report the frequency of PD occurring due to recurrent impulse voltages on the afore-mentioned insulating materials.