Abstract: In response to occasional instantaneous faults in substation transmission lines, in order to effectively avoid load loss caused by line shutdown, the relay protection is equipped with a reclosing function, greatly improving the stability of system transient operation. However, the short-term load impact of reclosing can have an impact on the operation equipment of substations such as circuit breakers, posing certain risks. This article studies the secondary abnormal situation caused by the voltage change of the 110 kV line after instantaneous fault reclosing. Through the disassembly of the voltage change body and analysis of the fault waveform, it is found that insulation aging and lack of suppression ferromagnetic resonance dampers lead to internal burning during resonance of the line voltage change.