Dynamic Model and Small Signal Analysis of Z-Source Inverter

Z-source converters, as one of the most noteworthy power electronic interfaces, have become so popular in the last decade. In this paper, the dynamic model of a three-phase six-switch Z-source inverter is presented. An accurate dynamic model is necessary for both determining the appropriate Z-source inverter with the efficient size of inductor and capacitor and designing the control system which guarantees the stability of the system. In this study, the steady state model and AC small signal analysis were used to obtain the dynamic model. To continue previous studies, in the proposed model, the state variables of the AC side were considered. Therefore, the model was more comprehensive and could be also used for three phase Z-source converter in the inverting mode. To validate the proposed model, the dynamic model was solved by MATLAB and compared with the real circuit implemented in the PSCAD/EMTDC. The simulation results demonstrated the accuracy of the proposed model for the three-phase Z-source inverter.