Measurement of V-t characteristics of suspention insulators to evaluate for lightning characteristics of traction power supply system

In d.c. traction power supply system, direct stroke of lightning to the overhead catenaries system and electric pole causes the continuing grounding fault and it results in the breaking of overhead wire. The countermeasure for lightning is one of the important issues to realize more reliable public transportation. In this paper, V-t characteristics of suspension insulators were experimentally measured in detail. It was confirmed that the flashover voltage increases about 40% or more in a short time region of V-t characteristics. Such measurements will be important and valuable for evaluation of lightning characteristics of traction power supply system and useful for reasonable proposal of countermeasures against lightning in the future.