Multi-loop control strategies of three-phase two-level current source inverter for grid interfacing photovoltaic system

The use of voltage source inverters (VSIs) in grid integration of photovoltaic (PV) systems have been research extensively and always be priority despite of the drawbacks of short lifespan of dc-link capacitor and inherent buck features. With regard to that, researchers continue to find feasible alternative topologies that may offer promising capabilities as in VSIs. Current source inverter (CSI) is one of the competitive options since it has inherent voltage boosting capability and continuous dc input current. These features are important requirements in PV application. Thus, this paper study on the option of using CSI system to supply the ac grid with the required controlled active and reactive powers. The presented control strategy uses number of feedbacks loops to enable fast and accurate tracking of the desired set-points with minimum overshoot. The selection of feedback control variables are discussed using stability analysis. The proposed control strategy is verified by MATLAB/SIMULINK platform.