173 / 2024-04-15 16:00:46

The Effect of Electrostatic Probe on Flat Insulator Charge Distribution During Online Measurement

Electrostatic Probe,HVDC GIL,Online Measurement,Surface Charge

The accumulation of surface charge on the DC GIL insulator will reduce the flashover voltage along the surface of insulator. The online measurement for the dynamic accumulation process of surface charge can better reveal the mechanism of surface charge accumulation. Therefore, the study of surface charge online measurement is of great significance. In this paper, a needle-plate charging experimental model with an electrostatic probe for online measurement is constructed. The surface charge online measurements on a flat insulator made of epoxy/Al₂O₃ are also performed. Meanwhile, the electric field distribution during online measurement is calculated. The results show that: compared with the case without probe, the maximum of the positive charge density accumulated on the surface of flat insulator increased by more than 50% when the probe was measured online. The positive charge region expands towards the probe position, a mass of positive charge accumulated near the sharp corner of the probe. In addition, the electrostatic probe obviously distorts the space electric field distribution, which further changes the original surface charge density distribution. This work can serve as a reference for online measurement of surface charge.