DSP-based control of main traction converter containing medium-frequency transformer

This paper deals with a main traction converter containing a medium-frequency transformer determined primarily for a new generation of suburban units operating on both ac electrification systems of 15 kV/ 16.7 Hz and 25 kV/ 50 Hz. The paper introduces proposed control of primary (trolley-wire connected) converters based on a predictive mathematical model and proportional-resonant controllers. A control strategy of secondary voltage source active rectifiers based on hysteresis current control is optimized for effective power flow through a medium-frequency transformer. The theoretical findings of this research are verified by experiments made on developed small-scale converter prototype of rated power of 12 kW.