Abstract：In this paper, taking a misoperation accident of gas relay caused by oil replenishment of on load tap changer under live working condition of 220kV transformer as an example, through computational fluid dynamics (CFD) numerical simulation, the internal oil flow characteristics of on load tap changer during live/power-off oil replenishment process are compared, and it is concluded that the cause of gas protection misoperation is that the temperature of oil replenishment under live condition is higher than that under power-off condition. The influences of different oil temperature, different oil temperature inside the switch, and sudden closing of the oil makeup valve on the flow rate of the gas relay are analyzed. The results show that the oil temperature inside the oil makeup has a great influence on the steady-state average speed of the gas relay, while the oil temperature inside the on load tap changer has a great influence on the maximum average speed. At the same time, the sudden closing of the valve during the oil makeup process will not cause the misoperation of the gas relay. Finally, some suggestions are put forward for the live oil replenishment of on load tap changer.
乔胜亚, 周鸿铃, 朱晨, 杨森, 李光茂. 一起有载分接开关带电补油致气体继电器误动事故分析[J]. 电气技术, 2022, 23(10): 86-90.
QIAO Shengya, ZHOU Hongling, ZHU Chen, YANG Sen, LI Guangmao. Analysis on misoperation of gas relay caused by oil replenishment of on load tap changer with load. Electrical Engineering, 2022, 23(10): 86-90.
2022, Vol. 23 
