Research on Power-tapping Method from Ground Wire for Online Monitoring Equivalent of Incoming Section of Substation

Online monitoring of substation incoming section is of importance for lightning protection and safety operation of the substation. Aiming at online powering for the monitoring device of the incoming section, the method of energy-drawing from ground-wire, power, effects of concerned factors, and overvoltage of the device are analyzed with EMTP-ATP program. The results show that the power level of the energy-drawing from ground wire is rather small (about 1 Watt or so), but usually enough to meet the requirements of the online monitoring devices for power. On this basis, combining the power level, lightning strike overvoltage and engineering feasibility of the energy-drawing approaches, the basic principle for selecting the approach is determined. The above-said research results could provides reference for the on-spot powering for online monitoring device of incoming section of the substation.