Partial Discharge Characteristics Under High Frequency High Voltage Stress and Their Impact on Solid Insulating Materials

Abstract

Insulation systems are increasingly exposed to combinations of high electric fields and high frequencies simultaneously. This can be linked to the growing integration of power electronic components and the ongoing development of power semiconductors. This trend also influences the occurrence of partial discharge (PD) phenomena, which can lead to higher stress when taking high-frequency components into account. Since the relevant and possible frequencies are steadily increasing, this work presents general investigation of PD characteristics for a wide frequency range up to 2 MHz and their impact on different insulating materials. The investigations have shown that the PD amplitudes increase with increasing frequency and that the number of PDs rises disproportionately. As a result, the intensity of PDs increases rapidly, reducing the lifetimes of the materials from over a year at 50 Hz, to days or minutes in the kHz range, and to seconds at 2 MHz.