Electromagnetic interference in control cables of substation caused by short circuit fault

This paper analyzed the principles of the electromagnetic interferences in low voltage control cable caused by short circuit fault from two main routines, coupling through current transformer (CT) or capacitor coupling transformer of voltage (CCTV), and generating from grounding system, their respective calculating methods are presented in this paper. Also the potential difference of the internal core and the shielding sheath at the cable terminals are calculated as an example, and the influences of the soil resistivity, the burial depth and the length of the control cable are considered. It is concluded that the interference voltage and current on the control cables caused by short circuit fault must be paid attention to by electric power engineers, since accurate operations of the metering, control, and protective equipment in the substation relies on dependable input signals.