Photovoltaic Grid-Connected System Based On Cascaded Quasi-Z-Source Network

Renewable energy sources are being widely used for Distributed Generation (fuel cells, solar panels, Wind power generators etc..,) because of their advantages. But they produce a very low output voltage. To interconnect a low-dc-voltage to residential loads a special voltage matching converter is required. This paper presents a back to back connection of cascaded quasi-Z-source network based step up DC/DC converter and 3-level diode clamped inverter. The proposed system reduces the component stresses and size of the converter. This network provides voltage boost and buck functions in single stage without any additional switches by the introduction of special switching strategy. The proposed cascaded qZSI inherits all the advantages of the traditional solution (voltage boost and buck functions in a single stage, continuous input current, and improved reliability). The results are analyzed by MatlabSimulink environment.