Summary of grounding system improvement of traction substation around Tokyo in East Japan Railway Company

Because we experienced sever lightning troubles in 2007 and 2008 around Tokyo, the improvement of grounding system of traction substation has been carried out since 2009. In this paper, the total contents of our trials from 2009 to 2013 were summarized. We already reported our trial in 2009 in the previous ICLP conference and this report is the follow-up report to that.