METHOD FOR DIAGNOSTICS OF AC POWER ELECTRIC CIRCUIT Russian patent published in 2008 - IPC G01R31/00 

FIELD: electrical engineering.

SUBSTANCE: method comprises periodic recording of voltage and current time dependence in three phases by means of the current pickups and voltage ohmic pickups that feature a linear amplitude-frequency response, along with advancing through the low-pass filter. The resulted signals are converted into digital form, the every-phase voltage and current spectra are shaped. The spectra mismatch availability or absence in every phase is checked up, the said mismatch being displayed as the availability of a notable frequency component in the current spectrum not available in the voltage spectrum at the same frequency, at least for one of the phases. In the latter case, the availability of a non-linear element in the electric circuit is recorded. In every nest record, the spectra mismatch is compared, i.e. a new mismatch and a previous one. Given the increase in mismatch with time for at least one phase, it is concluded that the non-linear element availability is caused by the fault development. No-mismatch-state changes speak in favor of the non-linear element availability making no problems for the circuit non-linear parameters.

EFFECT: lower labor input, simplification, higher accuracy.

6 cl, 6 dwg