Stochastic power quality study of distribution supply to metro transit railway

The proliferation of nonlinear loads resulting from new technologies has increased the levels of harmonics in power systems, and traction systems represent large nonlinear loads. This paper presents results of a simulation of the harmonics related to a mass transit railway system. Railway simulation results from the ATP version of Electromagnetic Transient Program (EMTP) with train schedules are presented. Summaries of the parameters affecting the harmonic performance of the traction system and estimates of the most predominant harmonics in a network are also presented and recommendations are made for the improvement of the power quality.