Design and digital implementation of voltage and current mode control for the quasi‐ Z ‐source converters

Two strategies of peak dc‐link voltage control of the voltage‐fed quasi‐ Z ‐source converters (qZSC) are analysed and compared. Different from the currently available literatures, the peak dc‐link voltage is estimated by summing the two capacitor voltages of qZSC. The voltage mode and current mode controls are derived based on the fifth‐order small‐signal model of the quasi‐ Z ‐source network with inductive load. Both controllers are digitally implemented using a digital signal processor (DSP)‐based direct digital design approach, where the real‐time workshop is used for automatic real‐time code generation for a TMS320F2808 DSP. Digital compensators are tuned using Bode diagram and discrete frequency response approaches with a graphical MATLAB/single‐input single‐output tool. The performances of the proposed control strategies are verified by the experimental results during start‐up, input voltage and load disturbances.