Optimal Sizing and Siting of Capacitor Bank in AC Autotransformer Electrical Railway System to Improve the Pantograph Voltage Profile and Reduce the Power Losses

Recently, AC electrical rail systems have been playing the important role in urban transportation system. One of the main problems of these systems is the voltage drop of pantograph. Deploying the capacitor banks in appropriate place not only can improve the pantograph voltage profile and reduce the power losses, but also provide additional benefits for system operation, like reducing the minimum allowable headway time value and improving the social welfare indices. In this paper, first the train is dynamically simulated and then, according to results, the power flow calculation is done. To achieving this, the electrical network is modeled with complete details and the optimal sizing and siting of capacitor bank with objective function of improving voltage profile and reducing the power losses are done. Simulations and calculations are done by BBA Traction Simulator Program, which is designed and developed by Alucast Iran Co. R&D team. The 2*25 kv AC autotransformer electrical railway network of Sadeghieh to Hashtgerd, Tehran is utilized to validate the applicability of presented method.