The system of fixed series capacitor bank compensation device（FSC） is used for the first time in UHV AC demonstration project and capacitor bank as its core component possesses such characteristics as large capacity

large numbers of units high voltage level etc.For ensuring safe operation of the capacity bank and enhancing the availability ratio of series compensation complete equipments

in accordance with the unbalanced protection setting principle of capacitor bank

reasonable range set by unbalanced current fixed value of double H type internal fuse capacitor bank is analyzed and obtained through simulation calculation of EMTP software.The effect of metal oxide voltage imitator

triggered gap

damping device and bypass circuit breaker is analyzed in the combination of the features of other equipments related to the operation of capacitor bank in the series compensation equipment

their coordination relation in the operation of capacitor bank is introduced and the purposes of rationally restricting the overvoltage of capacitor bank and guaranteeing the safe operation are achieved.