基于现场数据的变压器首次故障率研究

Study on the First Failure Rate of Transformer Based on Field Data

为指导电网中变压器的检修规划与可靠性分析,将变压器首次发生危急或严重缺陷定义为变压器首次故障,用统计分析方法与可靠性理论中的故障率建模方法分析了某省网变压器故障率随时间的变化规律。收集了某省网生产管理系统(production management system,PMS)中20年变压器缺陷记录,构建了不同投运时间的10个样本集合,分析了故障率随变压器运行年限的变化情况;选出了拟合效果最好的3个分布函数;建立了不同样本集的故障率Weibull分布模型,分析了故障率随变压器投运年份和运行年限的变化规律;建立了不同部件和不同变压器生产厂家的故障率Weibull分布模型,分析了各部件和厂家的故障率差异。研究结果表明:新投运的变压器偶然失效规律占主导地位,其平均故障前时间更长,且没有像传统浴盆曲线的早期失效规律,偶然失效期故障率为0~0.2次/(台·a);不同部件和不同厂家的故障率Weibull分布函数形状相似,但其平均故障前时间明显不同。所得变压器故障规律能有效指导供电单位对检修计划进行优化调整。

In order to guide the transformer maintenance planning and reliability analysis of the power grid,the critical or serious defect of transformer for the first time is defined as the first transformer failure,and the law of the transformer failure rate changing with time in a province of China is analyzed by using a statistical analysis method and failure rate modeling method in reliability theory.The transformer defect records of 20 years in the production management system(PMS)system of a provincial network are collected,10 sample sets with different commissioning time are constructed,and the variation of the failure rate with the transformer operating years is analyzed.Three distribution functions with the best fitting effect are selected.The Weibull distribution model of failure rate for different sample sets is established,and the change rule of failure rate with the commissioning time and the operating years of transformer is analyzed.Moreover,the Weibull distribution model of failure rate of different parts and different transformer manufacturers is established,and the difference of fault rate of different components and different transformer manufacturers is analyzed.The results show that the random failure law of newly commissioned transformers is dominant,their mean time to failure is longer,there is no early failure law like the traditional bathing curve,and the failure rate in the random failure period is 0~0.2 times/(set·year).The shape of the Weibull distribution function of the failure rate is similar for different components and different manufacturers,but their mean time to failure is significantly different.The transformer failure law obtained in this paper can effectively guide the power supply unit to optimize and adjust the maintenance plan.