针对采用FCT +FST的自动无功补偿装置的晶闸管的保护及续流问题 ,提出一种受保护及续流晶闸管控制的R -C旁路电路 ,将其与电抗器并联而不是与晶闸管并联的保护及续流方法 ,给出了R、C参数的计算方法。具有保护及续流灵敏完全、电抗器电流基本连续的优点 ,并可减少对交流电源侧的谐波污染 Aiming at the problem of thyristor protection and freewheeling of the automatic reactive power compensation device using FCT + FST, an R-C bypass circuit controlled by protection and freewheeling thyristor is proposed, which is connected in parallel with the reactor instead of in parallel with the thyristor Protection and freewheeling methods, the calculation methods of R and C parameters are given. It has the advantages of complete protection and freewheeling sensitivity and substantially continuous reactor current, and can reduce harmonic pollution on the AC power supply side