High Step-Up Isolated Multi-Input Converter Based on Three-Winding Coupled Inductor and Quasi-Z-Source for Excellent Voltage Gain With Independent Control and Expandability

This article introduces a high step-up isolated multi-input converter (HSIMIC), which utilizes a three-winding coupled inductor and a quasi-Z-source to obtain an extra-high voltage gain and to feature galvanic isolation. The HSIMIC only requires a minimum count of active switches. In HSIMIC, diodes have zero current switching (ZCS) features at turn-off, and leakage energy can be recycled. Based on the configuration of HSIMIC, the input sources can be processed simultaneously or individually. Even if either of the input sources is interrupted, the converter can still function and maintain the high step-up characteristic. In addition, the input port number can be easily extended to deal with more clean energy sources. The converter operation principle, theoretical analysis, essential parameter design, and simulations are carried out. A 400-W prototype is built and then tested to verify the theoretical analysis and validate the proposed HSIMIC.