This device meets the desires of the DL / T 849.6-2004 《Electrical Equipment’s Special Test Equipment General technology conditions part 6》, it is applicable to AC hipot test of high voltage cable, GIS and other large-capacity, high voltage capacitive test products. Adopting the principle of series resonance, by the way of adjusting frequency to finish the resonant, which can easily and accurately find the resonant point, the system of quality factor up to 80, light easily and can be combined in any way, and uses multiple protection devices, to make testing more convenient , safe reliable.In accordance with IEC standards IEC358（1990） Coupling capacitors and capacitor dividers and IEC1000 Electromagnetic compatibility.

(1)   Changing the device’s Inductance and making it resonant with large capacitance test product through adjusting core air gap.
  (2) Using power supply capacity is only 1 / Q of the output capacity. 
  (3) Weight is about the 1 / 10~1/5 of the traditional power frequency test transformer equipment.
  (4) No transient over-voltage when the test product is broken.
  (5) Wide range of applications, field application flexibility, large capacitance range of test product.
  (6) When the test product is broken down, the resonance condition is destroyed, short-circuit current automatically reduced to the minimum value, short-circuit current flows through the fault point is small.