Research on a multi-port converter with nine-switch cells

In order to drive multiple motors in the medium-voltage high-power industrial field and recycle the regenerative energy, a regenerative multi-port converter is presented, which is cascaded with several cells based on nine-switch inverter and PWM rectifier. The inverter in each cell can be extended to the 3N+3 switches. By comparing the existing cascaded technology of three-phase bridge inverter, a cascaded method suitable for nine-switch inverter is proposed. Then, the new converter topology, control strategy and comparison are analyzed. The converter provides a direct transfer path for regenerative energy among multi-port loads, and the number of switches, capacitors, and transformer windings are reduced, which can improve reliability. Moreover, the number of output-port can be extended flexible, so the converter is well-adapted to the multi-loads industrial fields. A 6 kV two output-ports cascade converter with six nine-switch cells is taken as an example, which has been tested in MATLAB/Simulink. The simulation results demonstrate the effectiveness of the proposed converter and control strategies.