Power quality improvement in Y/Δ electric traction system using a Railway Power Conditioner

AC railway traction loads are usually huge single phase loads. As a result, a significant amount of negative sequence current (NSC) is injected into utility grid. Moreover, harmonics and consumption of reactive power are further power quality problems that the supply network is encountering. In this paper, a compensation strategy with the aid of Railway Power Conditioner (RPC) is proposed to overcome the above-mentioned problems. Firstly, different kinds of traction transformers are evaluated and Y/Δ traction transformer is chosen. Then, a compensation strategy is initiated which is valid for all kinds of traction transformers and a control system is proposed based on it. Finally, the correctness of the analysis and proposed strategy is verified by the simulation results using Matlab/Simulink software.