Aging of Insulation Materials under Repetitive Impulse Voltage Stress

Abstract:
State-of-the-art fast semiconductors can create very high dv/dt during switching transition. These switching slopes reach values between 100 kV/mus and 250 kV/mus which result in a significantly higher stress in comparison to conventional setups in the range of 20 kV/mus. Together with high repetitive rates, this stress can damage insulation material and leads to partial discharges and electrical breakdown. The paper describes testing methods and results for two typical insulation materials. Degradation and breakdown mechanisms are analyzed with short term and accelerated lifetime tests.