High Temperature Partial Discharge Inception Voltage under Repetitive Impulse Voltage Applied to Motorette Samples

This paper presents a measurement method for partial discharge inception voltage (PDIV) and repetitive PDIV (RPDIV) of motorette samples with different terminal connections from room temperature to 155°C PDIV and RPDIV characteristics of the motorlet sample up to the high-temperature region were clarified. As a result, PDIV and RPDIV were found to decrease under high temperature environment. These results were interpreted in terms of a decrease in discharge inception voltage of microvoids which might exist in the motorette insulation layer, as well as an increase in the voltage shared to the voids due to an increase in the relative dielectric constant of the insulation with the temperature rise.