A 500 kV high-voltage AC fault current limiter (FCL) based on a high coupled split reactor (HCSR) is proposed by the National key R&D project team. Low impedance under normal conditions and high impedance under short-circuit conditions are accomplished by the cooperation of HCSR and high-speed switches. High-speed switches play an important role in current limiting processes

thus interruption characteristics of the high-speed switch in the 500 kV FCL are studied in this paper. The simulation model of the FCL and the external equivalent power grid are established. The short-circuit current and recovery voltage characteristics of the high-speed switch in FCL are simulated. The results show that maximum DC component of the short-circuit current of the high-speed switch reaches 91%

the maximum peak value is 118 kA

and the longest arcing time is 14.8 ms. There is a discontinuity in the curve of the short-circuit current peak and arcing time as a function of the short-circuit occurrence time; the peak recovery voltage of a single break of the high-speed switch has a maximum value of 87.5 kV under a three-phase ungrounded short-circuit condition

and the rate of rise of recovery voltage is 0.22 kV/s. The recovery voltage peak shows a period change with the short-circuit occurrence time

and the period is 10 ms. The effects of the shunt capacitor value and short-circuit ground resistance on the recovery voltage of high-speed switching are also studied. The research can be used for reference by R&D personnel and testers of 500 kV FCLs.