The conventional 10 kV dielectric loss measurement method for breaker’s shunt capacitor has some shortages in field measurement with increasing voltage.A high-voltage dielectric loss measurement method based on the technology of anti-variable frequency interference is proposed by adopting variable frequency power source

external standard capacitor and series reactors for resonant boost.Field measurements of 500 kV breaker’s shunt capacitors in Hezhou and Hechi transformer substations were conducted

and the results verified the proposed method.The relationships of measurement result with test voltage

humidity

RTV coating

and measurement mode

as well as the influencing factors in field measurement

are analyzed

which may benefit accurate judgement of insulation condition of a breaker’s shunt capacitor.