内部炭化对复合绝缘子绝缘性能的影响研究

随着复合绝缘子在高压线路中的广泛使用，其绝缘击穿事故也越来越多，其中内部炭化是引起绝缘击穿的重要原因之一。为了了解内部炭化对复合绝缘子绝缘性能的影响，建立了以复合绝缘子为研究对象的静电场有限元模型。基于电场数值分析理论，采用有限元分析法实现了对复合绝缘子电位与电场分布的精确计算，计算结果表明在两端金具与棒芯接触处场强最大。同时，对炭化后复合绝缘子的电压分布的分析计算表明，绝缘子的炭化区域基本丧失绝缘性能，并将加速未炭化部分的老化；高压端前数片绝缘子的电压比正常值高出27．09％，有绝缘击穿的可能；炭化区域绝缘子电压出现畸变，局部放电的可能性大大增加。

Influence of Internal Charring on the Insulation Performance of Composite Insulator

With the increasingly widespread application of composite insulator in high voltage transmission line, more and more accidents of insulation breakdown have occurred, and the internal charring is one of the important reasons for the insulation breakdown. In order to understand the influence of the internal charring to the insulation performance of composite insulators, the finite element model of the electrostatic field is established. Field theory and finite element analysis are used, accurate calculation of potential and electric field distribution of composite insulators are achieved, and the results show that the maximum field intensity is in both ends of the fittings and rod-core contact. Meanwhile, the study of the voltage distribution shows that the area of internal charring have almost lost the insulation performance, and accelerated the aging of area which has no charring. The voltage of the high side insulator is 27.09% higher than normal, there is more possibility of insulation breakdown. The charring region appears abnormal voltage, greatly increases the possibility of partial discharge.