Analysis of Thermal Faults for 110-220 kV Disconnector in Substations under New Power System

The current carrying capacity of the equipment can be reduced by heating of disconnector, which can influence safe and stable operation of the power system. The traditional thermal fault analysis of disconnector only takes a simple analysis of contact resistance measurement, deep micro analysis has not been analyzed. Based on macro analysis, this paper systematically studied the causes of heat generation of the disconnector through scientific and technological means such as morphology, metallography, and energy spectrum. Macroscopically, the increase of contact resistance on the disconnector’s surface results in the thermal fault. On the other hand, the surface of the disconnector has corrosion and dimples so that the grain boundary is weakened. And the oxidation resistance is decreased because of many carbides are dispersed. Based on the analysis process, the paper puts forward the cause analysis scheme and preventive measures for the heating fault of 110-220 kV disconnector.