A modeling method on electromagnetic interference coupling path of digital relay in power system

To realize systematic analysis for electromagnetic susceptibility (EMS), forecast for electromagnetic compatibility (EMC), a modeling method on electromagnetic interference coupling path of digital relay in power system was presented. The simulated model of electromagnetic interference coupling path can be gotten by this method through the system identifying according to the experiment data. A mathematical modeling of the input port of alternate current (AC) signal in digital relay under electrical fast transients (EFT) interference was also been constructed according to the input and output response of this module measured by oscillograph. Good agreements between the simulated result and the measurements demonstrate the validity of this modeling method.