抄録
The outline of countermeasures which have been invested since 2009 to enhance lightning-proof characteristics of traction power supply system in Tokyo metropolitan area is summarized in this paper. The three major countermeasures are as follows: making grounding conductor length short, reduction of grounding resistance of substation mesh and introduction of permanent grounding electrodes for grounding resistivity measurement. The effects of each countermeasure based on the measured data are also shown.
