Evaluation of Voltage Rise and Current Distribution at Transmission Line Tower Struck by Lightning (Invited Lecture)

At back-flashover analysis of a transmission line hit by lightning, equivalent circuit composed of multiphase conductors and a circuit model of a tower are usually employed for convenience in estimating its lightning performance. Electromagnetic field around a transmission line tower immediately after a lightning hit is complex, and relationship between the tower current and insulator voltages is not so simple as a distributed parameter line. Electromagnetic characteristics of a transmission line tower and its circuit modelling is reviewed and discussed.