A Systematic Approach for AC Electromagnetic Interference Study Between Railways and Nearby Power Lines

Railways and electric power systems are two critical infrastructures for the modern society's economic growth. Due to the difficulty of acquiring new lands for their expansion, railways and power lines often share a common corridor to optimize the use of land. However, the AC electromagnetic interference (EMI) between railways and nearby power lines has caused significant concerns to both electric utility and railway companies regarding personnel safety, railway signal-system compatibility, and AC corrosion. Current industrial practices offer a very limited knowledge base, the in-depth research in this area is largely missing, and there is no guideline available on how to conduct such EMI studies. In this article, we propose an effective systematic approach for the AC EMI study between conventional railways and nearby power lines under the steady state operation. This approach combines field measured soil resistivity and ballast resistivity with computer simulation modelling through CDEGS. One key benefit of the proposed method is that it avoids taking costly ballast resistance measurements, which impact the railway operation. The proposed method is validated by field measurements in two sections of railways in Manitoba, Canada. It paves a new way to create an accurate system model of AC EMI studies between railways and power lines, and provides a valuable guideline for transmission lines and rail design engineers.