LAUSR

ABSTRACT Impedance Source Inverter (ZSI) offers a solution to low output renewable energy sources, provides unconventional high boost. Interaction of Quasi-Z-Source Inverter (qZSI) and third order filter raises stability concerns. Dynamic interaction of DC and AC sides shows additional resonant frequencies, resonant characteristic needs attention when grid connected. In this paper, resonant characteristic of a third order passive filter based qZSI is explored. DC and AC sides dynamic model are analysed considering parasitic resistance, and optimum parameter selection for passive component and controller design is presented. Closed loop stable control is established for input variation taking care of multiple resonant feature. Disturbance rejection for an increased and decreased input is established by DC and AC side controllers, DC and AC side dynamics are handled using voltage loop and dual current loop, respectively. MATLAB/PSIM/dSPACE 1104 are used in this study, controller response is evaluated for two design cases (case I, II) and recommendations are made considering resonant characteristics, measured results validate the design and control methodology.