不同接触缺陷下气体绝缘组合电器发热—振动多场耦合数值建模与分析OA

Gas insulated switchgear(GIS)is widely used in power system.The contacts inside the GIS are the key parts to achieve electrical connection and,however,also the parts prone to frequent accident.It is therefore of great significance to find mechanical faults in time and judge the types of faults for maintaining the long-term and stable operation of GIS.In order to explore the corresponding relationship between the external temperature rise and vibra-tion characteristics and the type pf the internal contact fault,in this paper a electro-thermal-structural multi-physi-cal field coupling numerical calculation model of GIS under such four defects as spring missing(F1),bolt looseness(F2),weak spring contact(F3)and and insufficient docking depth(F4)is set up.The heating power and transient electrodynamic force are obtained by the calculation of eddy current field and transient electromagnetic field,which are uesd as the load to transmit to the temperature field and structural field,thereby calculating the tempera-ture rise characteristics and vibration characteristics under different defect states.The thermal-vibration test under different defect conditions is carried out on a GIS test platform.The error between the calculated value and the mea-sured value of the temperature rise is within 7.5%,and the error between the calculated value of acceleration and the measured value is within 11.2%,which verifies the rationality of setting up numerical model and the contact equivalence.The results show that temperature distribution of the enclosure has difference under different contact defects.The temperature rise of the contact is the highest in case of insufficient docking deptgh.The contact defects will change the vibration characteristics of the enclosure from such two aspects as distribution of electrodynamic force and mechanical connection structure.In case of missing bolts,the fundamental frequency vibration amplitude of the enclosure decreases obviously.The contents in this paper provides a theoretical basis for mechanical fault di-agnosis method of GIS based on temperature rise and vibration signal.