Influence Of Crack Defect On GIS Basin Insulator And Its Detection Method

In the environment of vigorous growth in the civil economy,the electricity load of city is growing,but the power supply and demand are becoming more critical,while the construction land is very limited.Gas insulated metal enclosed switchgear(GIS)has attracted more and more attention because of its small size,less land occupation and high operation reliability.It is more and more used in the construction of Urban Power Grid Substation.GIS is an indispensable and important equipment in the power system.,once the GIS fault occurs,it will have an impact on the operation of the power grid,so the research of GIS fault detection has begun to be paid more attention.As an indispensable insulation device in GIS,basin insulator also plays the role of supporting bus and separating two adjacent gas chambers.The importance of basin insulator in GIS is self-evident,but at the same time,it is also a component with relatively high failure probability in GIS,so the defect detection of basin insulator is especially important.Crack defect is one of the main defects that lead to basin insulator fault,so this paper will study the influence of crack on insulator.In this paper,we use finite element way to research the static characteristics,electrical characteristics and vibration feature of the basin insulator.The beginning is the stress research on the basin insulator,and the discuss on stress arrangement of the insulator.The aim is to analyze the damage of the cracks on the structure and performance of the insulator,and the influence of the cracks with different positions and sizes on the stress distribution of the insulator.Then,the electrostatic field of the basin insulator is analyzed,the electric field strength of the insulator is calculated,and the influence of the cracks in each position of the insulator and the cracks of different sizes on the electric field distribution of the insulator is analyzed.It is found that the cracks may lead to partial discharge of the insulator,and the potential risk of the crack defects of the basin insulator is exposed,which is the reference for the development of the basin insulator This paper provides an effective method for the study of depression.Then the modal analysis of the basin insulator is carried out.Compared with the natural frequencies of the intact insulator and the insulator with various crack defects,it is proved that the natural frequency can reflect the existence of the crack defects,and the variation law of the natural frequency of the insulator with crack defects is obtained.At the same time,the modal analysis method is applied to the GIS unit,which proves that the modal analysis is also suitable for the detection of GIS unit,and the natural frequency variation law of the crack defect is consistent with that of the insulator,which further proves that the vibration characteristics can effectively reflect whether the insulator has crack defects.Finally,the vibration characteristic detection system of GIS basin insulator is built to judge the health status of the insulator through the vibration signal,which provides a reference measurement method for on-line condition monitoring and structural defect detection of basin insulator.