A Novel Cascaded Quadratic High Step-up DC/DC Converter for Vehicle-mounted Photovoltaics

This article describes a non-isolated high step-up DC-DC converter. This converter uses a quadratic structure, two coupled inductors (CIs) combined with a switched capacitor (SC), voltage multiplier cells (VMC), and two power switches. The proposed converter achieves a high voltage gain at a lower turns ratio and lower duty cycle than conventional quadratic converters. The presence of a common ground between the input energy source and the load is more favorable for closed-loop control, making the converter suitable for vehicle-mounted PV applications. In addition, the proposed converter has the advantages of low voltage stress on the semiconductor components (switches/diodes), more compactness, and high efficiency. This article illustrates the principle of operation and steady state analysis of the proposed converter, followed by a discussion of the generalized induction method for voltage gain, and theoretical efficiency analysis, and a performance comparison with other converters. Finally, a prototype is made with an output voltage of 400V according to the design criteria, and the experimental results verify the accuracy of the theoretical analysis.