An experimental test of a theory of lightning-induced voltages on an overhead wire

Measured and calculated voltages induced on an unenergized overhead power line by lightning return strokes at distances greater than 5 km from the line are presented. The experiment was performed at the NASA Kennedy Space Center during the summer of 1985 and involved the simultaneous measurement of the voltage induced at one end of the top phase of a three-phase power line and the two horizontal components of the return-stroke magnetic field incident on the line. The effective ground conductivity was determined from previous simultaneous measurements of the vertical and horizontal electric fields. Experiments were performed for two cases: (1) all phases of the power line open-circuited, and (2) one end of the top line terminated at 600 Ω with the other end open-circuited and the other two phases open-circuited at both ends. The waveshapes of the measured and calculated voltages are in reasonably good agreement, and the reasons for observed discrepancies are discussed