High-voltage capacitive apparatus insulation fault detection method

The invention provides a high-voltage capacitive apparatus insulation fault detection method. According to the high-voltage capacitive apparatus insulation fault detection method, leakage current signals of at least four capacitive apparatuses connected to the same bus are selected as benchmarks for one another for calculating the dielectric loss of each capacitive apparatus; a lower dielectric loss value is subtracted from a higher dielectric loss value in every two capacitive apparatuses to obtain a relative dielectric loss value of each capacitive apparatus; then, by contrasting the changes in the relative dielectric loss values of the capacitive apparatuses, the diagnosis vector of a capacitive apparatus insulation fault is determined, the number of the capacitive apparatuses with the insulation fault is judged, and a fault diagnosis matrix is determined; finally, by contrasting the diagnosis vector with the built fault diagnosis matrix, the capacitive apparatuses with the insulation fault are located. The high-voltage capacitive apparatus insulation fault detection method not only can eliminate the interference caused by an external environment but also well solves the problem that a traditional relative measurement method may cover up the original ageing development tendency of the capacitive apparatuses, thereby effectively preventing the phenomenon of capacitive apparatus insulation fault missing detection from happening and ensuring the safety of equipment and workers in a transformer substation.