Variable frequency AC resonant test systems are mainly used for AC withstand voltage test of large capacitive test objects on site. The test objects include SF6 circuit breakers, GIS, power cables, tec.
With suitable tuning capacitor, the frequency range can be from 20Hz to 300Hz. The AC resonant test systems are applicable for partial discharge test of instrument transformers, coupling capacitors and metal oxide surge arresters with rated voltage under 1000kV.