基于频率响应分析法的高压套管绝缘检测仿真分析

Simulation Analysis of High Voltage Bushing Insulation Status Detection Using Frequency Response Anslysis Method

近年来,电网中套管事故频发,给国民经济造成了重大损失,引起了电力运行和检修部门的高度关注。因此及时开展高压套管内部绝缘状况的有效检测手段研究是十分重要和迫切的。为此,主要探讨了用基于介质响应原理的频率响应分析(FRA)法对套管进行绝缘检测的机理,采用MATLAB软件建立了套管结构的RC模型,仿真分析了各参数变化时FRA曲线的特征,以及隔离刀闸断口接地和高压引线的影响,并结合实测曲线进行了相应的对比分析。研究结果表明,当套管发生绝缘缺陷而出现比较明显的松弛极化特征时,FRA曲线会出现相应的凹陷,凹陷的数目和具体变化情况与套管的绝缘缺陷程度和松弛极化过程有关。理论仿真和实测曲线的吻合度较好,证实了FRA法应用于套管绝缘状况检测的可行性。

In recent years,there are many bushing faults in the power grid,which have brought heavy loss to the national economy and raised great attention of the power operation and maintenance department＇s concern,so it is important and urgent to do some research on the inner insulation status of high voltage bushing.This paper mainly discusses the mechanism of frequency response analysis（FRA） method on the insulation detection of bushing,which is based on the dielectric response theory.It builds the RC model of the bushing instruction in MATLAB and analyzes the characteristics of FRA curve with different simulation parameters,as well as the influence of isolation switch grounding and high voltage wire.Results show that obvious indentation in the FRA curve will appear when the bushing has some insulation defects.The number and change state of the indentation in FRA curve is related to the degree and relaxation polarization of the insulation defects of the bushing.Simulation results were compared with the real detection results on the spot and it was found that these two agreed well with each other,which indicates the feasibility of FRA method.