Surface aging condition monitoring of glass insulators in substations based on laser transmission spectroscopy

Abstract

The aging of glass insulator materials in substations leads to a decrease in the overall insulating performance of insulators, which affects the safety of power system operation. In order to effectively and accurately detect the aging condition of the glass insulator surface in a substation, a technical method based on laser transmission spectroscopy is proposed to characterize the aging state of glass insulators. During the application of laser transmission spectroscopy, a high-frequency laser is used as the incident light source, and the refractive index and the corresponding deflection angle are calculated during the analysis of the high-frequency laser’s vertically incident optical path; the electromagnetic wave theory is integrated to calculate the sample’s absorption coefficient, transmittance, reflectance, signal time delay, and other relevant optical parameters so that non-destructive testing of the glass insulator can be carried out. Experiments were carried out on glass insulator specimens with different aging degrees, and the corresponding relationships between different aging degrees of glass insulator media, absorption coefficients, and signal time delays were obtained by analyzing the laser transmission spectra of the specimens and integrating the time-domain spectral analysis. The test results show that there are obvious differences in the absorption characteristics of glass insulators with different aging degrees in the high-frequency laser band, and the longer the aging time is, the more obvious the absorption characteristics are and the larger the corresponding absorption coefficients are.