Theoretical Calculation and Experimental Study on the Effect of Gas Content on Heat - Induced Bubble Formation of Oil-paper Insulation

Increasing temperature will cause heat-induced bubbles to form in oil-paper insulation, which will threaten its insulation performance, and the gas content will affect its inception temperature. In order to clarify the influence of gas content in oil on the inception temperature, the calculation model of heat-induced bubbles (ITBE) was improved to calculate the inception temperature under different gas content. Meanwhile, the corresponding experimental platform and winding model were built to carry out the corresponding experimental research. The results show that the calculated results were in good agreement with the experimental results. The increase of gas content will lead to the decrease of inception temperature. The lower the water content of paper, the more obvious the influence of gas content. This can be explained qualitatively by the relation of pressure in the bubble germ. The research is helpful to provide reference for the condition evaluation of oil-paper insulation.