500kV电力变压器匝间绝缘模型线圈的电老化特性

摘要

In order to solve the problem of transformer turn-to-turn insulation is the main positions of power transformer damage accident.500 kV power transformer turn-to-turn insulation model coils were designed and fabricated to study the electrical aging characteristic of turn-to-turn insulation.By the results of preliminary test of the model coils,the right experimental scheme was selected;then the method was determined to calculate the parameters of the model of inverse power on the basis of maximum likelihood method;the parameters were calculated under different amount of data.The result of analysis show that different amount of data make parameters calculated different and it needs at least four kinds of time that voltage continue to obtain the right voltage endurance coefficient N,and it was got in a reliable way under 10 kind of time.In this way,the value is 13.38.Finally,the inverse power model between aging life and electric field strength was obtained through the calculation and simulated analysis,which can be used to guide the actual transformer production design.%针对变压器匝间绝缘是电力变压器损坏事故中的主要损坏部位的问题,设计并制作了500 kV电力变压器匝间绝缘的线圈模型,研究匝间绝缘的电老化特性.根据模型线圈预试验的结果,确定了实验方案,并基于极大似然法思想确定求取反幂模型中的参数方法;最后求取不同数据量下的参数值.分析结果表明:不同数据量下所求得的参数值不同,若使电压寿命指数N不出现异常值,至少需要在4种电压持续时间下进行实验;在10种电压持续时间下可得到可靠的电压寿命指数N,其值为13.38.最终通过简单计算及仿真分析求得了老化寿命与电场强度间的反幂模型,用于指导实际变压器的生产设计.