Electrostatic discharge effect on safe distance determination for 500 kV ac power lineʹs helicopter inspection

The effect of electrostatic discharge on safe distance determination for 500 kV ac transmission lineʹs helicopter inspection is investigated. Potential difference exists while helicopter is near the power transmission line, which is harmful to the inspection persons. The electric field in the helicopter cabin is calculated when it is near the power line. The result indicates that the potential difference becomes higher with the decrease of the distance between the helicopter and transmission line. Considering the discharge energy and the guarantee of the personsʹ safety, the safe distance for 500 kV ac transmission lines is determined as d ≥ 15 m.