Test circuits and diagnosis methods of HV SF6 and minimum-oil circuit breakers at capacitive currents switching

The paper presents test circuits and measurements for overvoltage determination on capacitive currents switching when disconnecting single capacitor banks and overhead lines and experimental results in a high power laboratory (HPL) and a power network obtained using high voltage SF₆ and minimum-oil circuit-breakers. Also, the paper presents diagnosis methods for switching process behaviour of SF₆ circuit-breakers using no-load dielectric strength characteristics