Impact of WBG Converter Voltage Rise-Time and Switching Frequency on the PDIV of Twisted Pairs

The effect of wide bandgap converter on the partial discharge inception voltage (PDIV) of enameled magnet wires was investigated. Tests were carried out using an optical detection system, changing the rise time and the switching frequency. The experiments showed that neither the rise time nor the switching frequency influence the PDIV. Physically, this finding supports the idea that the permittivity does not change in the frequency range of the impulse voltage spectrum. However, the overshoot can affect PDIV measurements as neither the peak voltage nor the dc bus voltage provides an accurate evaluation of the PDIV.