高压套管油纸绝缘气泡生成特性.

Due to the long-term effect of the electric field and the heating from the conductor heating, many bubbles will precipitate on the surface of the oil-paper inside the bushing. When the bubbles move to the strong electric field, the partial discharge is caused, which seriously threatens the safe operation of the transformer hushing. Therefore, the conditions for bubble separation were analyzed based on the physical analysis of the liquid. The test platform for bubble observation inside the bushing oil-paper insulation was established, and lest samples with different water content were tested subsequently. The rapid heating method was employed to study the bubble generation over the oil-paper surface, and the variation of initial temperature of bubbles was obtained. The bubble initiation temperature between 0.5 °C/min and 5.5 °C/min was explored through experiments. The results show that the bubble initiation temperature differed by a maxi-mum of 30 °C at different temperature rise rated. When the rising rate is greater than 3 °C/min, the bubble initial temperature begin to decrease significantly; while when the temperature rising rale is less than 3 °C/min, the bubble generation initial temperature is more dispersive hut the result is normally distributed; When the moisture content increases, the initial temperature of bubble generation decreases significantly. When the moisture content increases from 2. 7% to 6. 8% , the initial temperature of the bubble drops by 44 °C. The research results have engineering application value for analyzing whether there are bubbles inside the bushing during operation, evaluating the internal insulation status of the transformer bushing, and ensuring the safe and stable operation of the power transformer. [ABSTRACT FROM AUTHOR]