Condition assessment of abnormal temperature rise of GIS based on multi physics coupling
                                             DAI Wei wei1, GAO Kai2, MA Li1, JIN Li jun1
（1.School of electronics and information engineering， Tongji University， Shanghai 201804， China;2.Shanghai Electric Apparatus Science Research Institute（Group） Co.， Ltd.， Shanghai 200063， China）

Abstract: Aiming at the influence of abnormal rise of gas insulated switchgear （GIS） on internal insulation performance and equipment safety， the relationship between temperature rise of shell and internal defects was researched. A method for estimating the internal equipment temperature distribution based on the temperature rise of the GIS shell was proposed， and the operation condition was assessed to realize the internal fault diagnosis of GIS. The simplified three dimensional model of 252 kV GIS disconnector was established， and the steady state temperature field distribution was obtained by the electromagnetic heat fluid solid coupling simulation combined with the COMSOL software. By the GIS simulation platform， the temperature test under different working conditions was carried out to verify the correctness of the simulation calculation. The relationship between the conductor temperature and the maximum temperature of the shell was constructed， and the method of estimating the existence of internal overheating defects according to the temperature rise of GIS shell was established. The results indicate that the internal heat transfer process can be simulated effectively by the method of multi physics coupling calculation and the running status of GIS can be estimated accurately by measuring the temperature rise of the shell， which supports the state maintenance of GIS equipment.

Key words: GIS equipment; multi physics coupling; steady temperature profile; condition assessment