Measurement of the Switching Over-Voltages at the Disconnection of the High Voltage Shunt Reactors in the Romanian Power System

The paper presents the measurements of the switching over-voltages made in the Romanian Power System, at the 400/220/110 kV Urechesti substation at the disconnection of a 400 kV, 100 MVAr shunt reactor type DFAL, Siemens, Germany, in 3 consecutive versions. The first one is for shunt reactor controlled by live-tank oil circuit breaker, the second one is for shunt reactor controlled by SF₆ circuit breaker, and the third one is for shunt reactor controlled by SF₆ circuit breaker and synchronize device.