Determining the Protective Grounding Conductor Impedance to Ensure Safety in Carrying out Work on the Disconnected Power Line
It is proposed to ensure safety in carrying out work on a disconnected overhead power line by using a grounding conductor at the workplace having the impedance at which the induced voltage will be decreased down to permissible values. For reliably determining the necessary grounding conductor impedance, the results from multiple measurements of the induced voltage and current at the overhead power line point in which the work is carried out are used. Based on the results of measurements and solution of the inverse problems, empirical formulas for the functions of induced voltage and current in the considered place at which work on the overhead power line is carried out are determined. The necessary impedance of the grounding conductor at the workplace is determined using the obtained empirical formulas. As a result, a procedure has been developed using which it is possible to determine the grounding conductor impedance that ensures safety of work carried out at the considered place of the disconnected overhead power line whatever the combination of operating currents through the influencing overhead power lines.