New Topology for voltage balancing in railway substations

This paper deals with a new technique of voltage unbalance compensation for single phase railway substations. Using the concept of Chopper Controlled Impedance, the authors study the feasibility of an active Steinmetz circuit based on AC choppers. The low power losses in semiconductor devices make the proposed topology an interesting alternative to classical solution like VSI based. Design criteria are presented using information got from measurements carried out in a substation of the French Railways. Finally, the study is validated by means of simulations and experimental results carried out on a 1.5 kVA prototype.