Study on Characteristics of Electromagnetic Interference Caused by Metro Train Movement

Abstract

With the rapid development of the urban power grid and metro system, their mutual influence has become more and more serious. The dc magnetic bias of the transformer caused by the metro becomes the main research direction. In this paper, the characteristics of dynamic electromagnetic coupling between metro trains and transmission lines are studied. First, the motion equation of the metro is written out according to the running law of the train, and three coupling relations are given according to the position of the train. The calculation method of dynamic induced voltage is deduced. Then the influence of parallel length and distance between the metro and transmission line on induced voltage is studied. The dynamic induction voltage increases first and then decreases with the increase of the parallel length of the metro and transmission line and decreases with the increase of the distance between them. It is proposed that the electromagnetic coupling of a single train has limited influence on the dc magnetic bias of transmission lines, but the influence of dynamic electromagnetic coupling cannot be ignored when multiple trains are running simultaneously.