Research on Measurement Method of Electric Field Intensity on Surface of Metal Conductor

Insulation level of power equipment is always dependent on the electric field intensity (EFI) on the electrode surface and in internal dielectric of power equipment. However, as we know, the EFI on the electrode surface cannot be measured so far. The method for electronic EFI measurement is proposed in this article. The physical model for the experiment with an analytical solution to EFI is designed. The EFI measurement is conducted at many different points on the metal surface of high-voltage conductor of the physical model. Combined the method of images with the electric axis method, the analytical solution of the electric field at different positions on the surface of a high-voltage conductor is obtained. Comparison between measurement results and computation results of the EFI is made. The relative error between them is less than 5%. The proposed method is verified. The proposed method of EFI in this article can be used in study of compact power equipment, online detection, state evaluation, and the study on safety and stability of power grid.