Measurements of the voltage induced on an overhead power line 20 m from triggered lightning

Voltages induced on a 448-m power distribution line by eleven return strokes in three lightning flashes artificially initiated 20 m from one end of the distribution line and the corresponding vertical electric fields at 500 m have been measured. Two types of induced-voltage waveforms were recorded: oscillatory and impulsive. The former exhibit peak values that range from tens of kilovolts to about 100 kV; the latter show peak voltages nearly an order of magnitude larger. Both types of induced voltage waveforms were observed to occur for different strokes within a single flash. Relatively successful modeling of the oscillatory voltage waveforms is presented. Modeling of the impulsive waveforms proved unsuccessful, probably due to those waveforms being in part associated with a failure, perhaps an unexpected flashover, in the measuring system.<
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