A Method for Measuring Electric Field Distribution Along Insulator Surfaces Based on Electroluminescence Effect and Its Image Processing Algorithm

The measurement of electric field distribution along insulator surfaces plays a vital role in the design of insulators. This article proposes a measuring method of electric field distribution and its image processing algorithm based on electroluminescent effect. Unlike traditional electric field probes, this method is a noncontact measuring method that could reduce electric field distortion along insulator surfaces. There are three main steps: spraying epoxy coating mixed with ZnS:Cu electroluminescent powder on insulator surfaces, photoing luminescence images under different voltages, and deducing the electric field distribution by the proposed image processing algorithm. The surface electric field distributions of three typical insulators used in gas-insulated switchgear/gas-insulated transmission line (GIS/GIL) are measured. Compared with simulation results, the measurement errors of the disk insulator, the basin-type insulator, and the tri-post insulator are less than 2%, 4%, and 2.5%. This method provides a new way of measuring electric field distribution along insulator surfaces.