Highly Sensitive Wideband Measurement Method of DC Micro-Discharges Based on Optimized Subdivided Electrode System

Abstract

The presence of micro-discharges, which is caused by micro-protrusions or conductor surface roughness, was a potential hazard leading to non-uniform charging at the gas-solid interface of the insulators in DC gas-insulated equipment. It is crucial and necessary to measure micro-discharges. However, the low sensitivity of conventional methods limits their measurement range. In this letter, a highly sensitive wideband DC micro-discharges measurement method based on the optimized subdivided electrode system has been achieved. Synchronous measurements using ultra-high frequency (UHF) and photon counting were conducted to evaluate the performance of this method. Results show that this method realizes the highly sensitive measurement as low as 0.02 pC. The integrated charge differs from the injected charge of the calibrator by only 0.6% and achieves lower partial discharge inception voltage (PDIV) compared with other methods.