Development of repetitive voltage impulse generator and automatic repetitive PD inception voltage measurement system for testing inverter-fed motor insulation

In this study, a repetitive impulse voltage generator has been developed for detecting RPDIV (Repetitive Partial Discharge Inception Voltage) and RPDEV (RPD Extinction Voltage) of motorette test specimen designated in IEC60034-18-41-TS in the inverter surge. The fabrication of a generator is also described using a high-power semiconductor module and a variable amplitude DC power source. A design methodology for the impulse generator for partial discharge test is developed. The developed generator can generate a given number of voltage impulses with rise time of larger than 200 ns and arbitrary pulse width at less than 10 kHz of repetitive frequency and variable rate of applied voltage rise. Automatic PD measuring system including the repetitive voltage impulse generator was also developed. The system allows automatic data acquisition of RPDIV and RPDEV defined according to IEC61934TS as well as conventionally defined PDIV and PDEV. We report the result that repetitive impulse voltage was applied to confirm the insulation dignity of inverter-fed motor insulation using the repetitive impulse voltage generator.