Abnormal Analysis and Preventive Measures of Arrester on Middle Voltage Side of Main Transformer

According to the special live detection work of infrared accurate temperature measurement carried out in a 110 kV substation during peak winter load, this paper found that the temperature of B-phase arrester at the middle voltage side of the 110 kV main transformer is abnormal, and the leakage current of this phase arrester is larger than that of the other two phases. Carried out insulation resistance, DC reference voltage and leakage current testing after power outage. After disassembling, it was found that there were abnormal phenomena such as surface oxidation of aluminum support parts and obvious traces of water inlet inside the B-phase arrester. After disassembling, insulation resistance test was carried out on each valve plate. It was plate overed during the pressurization and infrared temperature measurement testing that the valve plates were abnormal. It was determined that the reason for the abnormal temperature of the arrester for phase B is its long-term dampness. At least 6 of the 13 valve plates have deteriorated, indicating that the arrester for phase B has entered the accelerated deterioration phase. B phase arrester has entered the deterioration accelerated stage. In addition, suggestions and conclusions are put forward for the abnormal heating of arrester, and preventive measures are proposed to avoid the defects affecting the safe and stable operation of power grid equipment.