Abstract
The causes of lightning faults are classified into the direct lightning strokes and induced lightning strokes, which are identified by the characteristics of the lightning overvoltage. In the past, the lightning countermea-sures were mainly directed toward the latter, and attentions have been focused on the installation of arresters, ground wires, and reinforcement of insulators. However, the lightning faults continue to occur, and it is extremely important to clarify the fault characteristice of lightning surges and study the effectiveness of various lightning countermeasure equipment by considering both direct lightning stroke and induced lightning stroke in order to prevent lightning faults in future. In this research, the EMTP has been applied to the direct lightning stroke, and the induced lightning analysis program for multiple conductor systems has been applied to the induced lightning stroke, to study the effectiveness of lightning countermeasures provided by combination of various lightning countermeasure equipments, and we analyzed and evaluated the most effective lightning protection schemes based on verification tests on the full scale models as well as economic considerations.
