Lightning Overvoltage of Rails and Signalling Cables in Electrified / Non-electrified Section

Effective and economical lightning protection measures are necessary for the railway signalling systems because suspended operation or train delays due to lightning damage may cause social disturbance. Railway signalling systems are mainly composed of signalling cables laid on the ground surface, rails and overhead power lines. The authors have measured lightning overvoltage of these components of railway signalling systems in the field. The measurement in a non electrified section was conducted from 2010 to 2013, and the measurement in an electrified section has just started from 2015. This paper describes the measurement results in the electrified section and the correlation between lightning overvoltages of the components and lightning conditions, such as the stroke current and the strike position. Moreover, this paper indicates the difference of lightning overvoltages of signalling cables and rails between the electrified section and the non-electrified one.