Voltage control device for protecting surge arrestor

PURPOSE: A voltage controller for protecting a lightning arrester is provided to prevent damage to the lightning arrester due to frequent TSC(Thyristor Switched Capacitor) switching operations of an SVC(Static Var Compensator) by controlling an operation of the SVC according to the temperature of the lightning arrester. CONSTITUTION: A temperature sensor(20) converts the temperature of a lightning arrester into a digital signal. An operator(30) includes a transformer, a first memory, and a comparator. The transformer calculates a storage energy value from the digital signal. The first memory stores the energy capability of the lightning arrester. The comparator compares the energy capability with the storage energy value. An auxiliary controller(50) controls the on/off status of the SVC of a main controller(40) according to the comparison result of the operator.