试验回路参数对污染条件下绝缘子电气特性的影响研究

Influence of Test Circuit Parameters on Electrical Characteristic of Insulators at Contamination Condition

绝缘子是电网中最常用的电气设备之一,对于保证电网安全运行具有重要作用,但实际在运绝缘子的电气特性与高压实验室得出的结果存在一定差异。为此文中提出了一个考虑试验回路—绝缘子相互作用的数学模型,用于模拟污秽条件下复合绝缘子和瓷绝缘子的电气特性,通过与实际试验结果进行了对比验证了模型的有效性;最后计算分析了试验回路参数、ESDD、绝缘子伞裙结构、电压等级、试验布置等因素对绝缘子电气特性的影响。结果表明,文中提出的模型能够有效模拟具有不同表面润湿性或疏水性的复合绝缘子的电气特性;分析结果显示实际电力系统等试验回路参数的变化会导致绝缘子闪络性能低于实验室通过试验得到的预期值,其中瓷绝缘子的相对降低程度相比复合绝缘子更显著。

Insulator is one of the most commonly used electrical equipment in power grid and plays an important role in ensuring safe operation of power grid.However,certain difference between the electrical characteristics of insulator in actual operation and the result obtained from the high voltage laboratory is existed.One mathematical model considering the interaction between test circuit and insulator is proposed in this paper and is used for simulating electrical characteristics of composite insulator and porcelain insulator at contamination condition.The effectiveness of the model is verified by comparing it with the actual test result.Finally,the influence of such factors as test circuit parameters,ESDD,shed structure of insulator,voltage and test layout etc on electrical performance of insulator is calculated and analyzed.It is shown by the result the model proposed in this paper can be able to simulate effectively the electrical characteristics of composite insulators with different surface wettability or hydrophobicity.It is shown by the analysis result that the variation of test circuit parameters of actual power system can cause the flashover performance of insulator to be lower than the expected value which is obtained through laboratory tests,in which the relative reduction degree of porcelain insulator is more significant than that of composite insulator.