System design of series Z-source inverter with feedforward and space vector pulse-width modulation control strategy

For Z-source inverter (ZSI), the peak DC-link voltage is the actual voltage fed to the inversion stage. Controlling the peak DC-link voltage at the constant level can effectively decrease the voltage stress and simplify the design process of the inversion stage. By adopting input feedforward control, the constant peak DC-link voltage can be achieved. The feedback control of the peak output voltage is utilised to obtain the constant output without steady-stage error under load variation. Both the peak DC-link voltage and ac output is controlled to a desired level under different input and load condition. A prototype is built in the lab, and detailed design procedure of the ZSI with space vector pulse-width modulation scheme is given. Simulation and experimental results are presented to demonstrate the feasibility of the proposed control strategy and parameters design method.