Patent ID: 8339111

Claim:
A reactive power compensator that includes a capacitor bank unit including a plurality of parallel connected capacitor banks, and compensates reactive power supplied by a power system by combining the capacitor banks, each of the capacitor banks having a capacitance different from other capacitor banks, and controlling connection/disconnection of the capacitor banks stepwisely by a unit of a basic capacitance, wherein each of the capacitor bank units is divided into a first capacitor bank having the basic capacitance, and at least one second capacitor bank that includes a plurality of subbanks, a capacitance of each one subbank included in the second capacitor bank is set to a capacitance of the capacitor bank located immediately before the subbank, and when any one of the first capacitor bank and the second capacitor bank fails, each of the second capacitor bank following failed capacitor bank substitutes for the capacitor bank located immediately before the second capacitor bank.