RAIL-TO-EARTH RESISTANCE ASSESSMENT FOR A MEDIUM CAPACITY TRANSIT SYSTEM WITH CONTINUOUS NEGATIVE RAILS BY POTENTIAL MEASUREMENT

摘要

This paper presents the development of a qualitative and quantitative assessment of the resistance to ground for the electrically continuous negative rails of a medium capacity transit line of the Taipei Rapid Transit System. Using synchronous potential measurements at three stations we examine potential profiles to locate potential rail sections with low resistance to ground qualitatively. Also the voltage sag values are used to quantitatively calculate rail-to-ground resistance per unit length. The approach presented in this paper requires only voltage measurements with the traction current as the energization source. Thus, this approach can be performed as a routine maintenance procedure to obtain rail-to-ground resistance values from a system-wide point of view.