High-Gain Z-Source DC-DC Converter With Low Voltage Stress for Photovoltaic Power Systems

In photovoltaic (PV) power generation systems, to obtain the best energy conversion efficiency, effective DC-DC converters must balance the solar panels output voltage with the voltage on the DC bus. The converter is designed to have low voltage stresses on each device, and it has the characteristics of a wide input range and high gain. The following actions were done to confirm that the proposed converter had a number of features appropriate for PV systems and an experimental verification platform was established based on theoretical analysis and small-signal modeling. The input range of the scaled-down experimental prototype is 40-80 V, with a rated output of 400 V and a rated power of 200 W. The experiment confirms the accuracy and feasibility of the theoretical analysis for the converter. The converter has a high voltage gain and can be used in PV system to match the voltage of the PV panels and the DC bus. The converter has the advantages of common ground structure and low voltage stress. Experiments verify that the converter has good dynamic characteristics.image