Influence of AC corona discharge on contamination layer of composite insulator surface

Pollution layer on insulator surface may change under corona discharge during the long-term service of insulators, which would influence the performance of contaminated insulators. In this paper, AC corona discharge experiments are studied by utilizing a 31-needle-to-plate electrode system. The Scanning Electron Microscope (SEM), Fourier Transform Infrared Spectroscopy (FTIR) and X-ray Photoelectron Spectroscopy (XPS) are used to study the characteristic variation of pollution after corona process. It was concluded that hydrophobicity, microstructure and chemical composition of pollution obviously changed after corona process.