Leader progression model application for calculation of lightning critical flashover voltage of overhead transmission line insulators

The paper presents a method for calculation of lightning critical flashover voltage (CFO) of overhead transmission insulators. The method is based on the application of leader progression model (LPM). CFO was calculated and measured in high voltage laboratory for different polymer and glass insulator strings equipped with arcing horns and grading rings fittings. Comparison of laboratory measurements and calculation results showed that CFO can be determined with good accuracy by using the presented method.