| 摘要 |
The invention relates to a method for monitoring fault currents in an electric AC mains having a predetermined mains frequency. According to the invention, current values of electric currents to be monitored are recorded (12a 12d), after which the recorded current values are converted into digitized current values (14). Afterwards, these digitized current values are used to calculate (16) cumulative current values, from which blocks comprised of the cumulative current values are formed (18) according to the phase position of a mains voltage signal. The blocks are then split (24) into spectral components. The spectral components of the blocks are then monitored (36) with regard to an exceeding of spectral limit values in order to evaluate the danger of the fault current. |
