Influence of temperature on frequency domain spectroscopy detection of transformer bushings

Abstract

Frequency domain spectroscopy (FDS) technology has been widely used to evaluate the insulation state of electrical equipment. However, there are still many in-adaptability when using FDS technology to evaluate the insulation state of transformer bushings. Especially, the result will be affected by temperature in the quantitative diagnosis of moisture degree. The influence of different temperatures on FDS detection data of transformer bushings has been studied to solve this problem in this paper. To obtain the FDS test data curves of transformer bushings at different temperatures, the transformer bushings experiment platform was built in the laboratory. And the bushing samples at different temperatures was measured by FDS detection method, which started at 30 °C and rising at 10 °C intervals until the temperature reached 80 °C. The result shows that the temperature will have a serious impact on the FDS detection data, especially the R0 and C5 in the extended Debye model. To solve the influence of temperature, FDS data correction curves with different temperature has been built in this paper. And its feasibility has been verified by FDS data of transformer bushings with 0% and 1.89% water content. The obtained results can promote the application of FDS method in the evaluation of transformer bushings insulation state.