Traction drive with medium-frequency transformer - Control strategy based on NULL vectors

This paper presents research motivated by industrial demand for special novel high voltage traction drive topology devoted to minimization of traction transformer weight against classical locomotives operates on both 25kV/50Hz and 15kV/162/3Hz trolley voltages. This paper deals with testing of whole traction converter prototype in configuration: two single phase matrix converter + medium frequency transformer + single phase voltage-source active rectifier in selected transient states and verifying of proper function of control algorithms. The new control of traction converter based on inserting zero vectors has been proposed to smooth taken trolley current.