Impact of electric potential due to faulted overhead ground wire on distribution system equipment

摘要

This paper analyzes the impact of electric potential (EP) due to faulted overhead ground wire (OHGW) on distribution system equipment. The fault current injection to direct OHGW, which may cause insulation failure to electrical equipment, was simulated using the current distribution electromagnetic interference grounding and soil structure (CDEGS). Three cases were investigated on a 115/22 kV substation and a 22 kV distribution of provincial electricity authority (PEA): 1) the existing system, 2) bonding between the ground grid substation and the ground rod located in earth under the riser pole, and 3) the OHGW of the take-off located in the substation and the OHGW of the riser pole are connected. It can be confirmed from the study results that bonding between the ground grid substation and the ground rod located in the earth under the riser pole offers an effective means to help decrease the EP between the OHGW and the ground, therefore reducing the risk of equipment damage.