The traditional protection devices for the high voltage step controlled shunt reactor(SCSR)

detect the inter-turn short circuit fault of the control winding through differential protection based on the magnetic balance and self-produced zero sequence over-current protection. The devices have the inadequacy of low sensitivity

slow speed and difficult setting. For this reason

a new method of inter-turn protection for the control winding of SCSR is proposed. It is a comprehensive utilization of the voltage

the current of the net side winding and the current of control winding

the differential over-current detection element

the zero sequence over-current detection element and the anomaly detection element put together

which can improve the protection speed

sensitivity and reliability during an inter-turn fault with the control winding as well as simplify the protection setting set.