A Novel Three-Winding Coupled Inductor-Based High Step-Up DC-DC Converter for Renewable Energy Application

This article presents a novel nonisolated high step-up dc-dc converter for renewable energy generation systems. The converter combines a three-winding coupled inductor (CI), voltage multiplier cells (VMCs), and two power switches with simultaneous operation. Compared with existing high step-up converters, the proposed converter can achieve high voltage gain under a low number of turns ratio while avoiding a large duty cycle. Moreover, the passive clamp circuit recycles leakage inductor energy and reduces the voltage spike of switches. The continuity of input current and existence of common ground between the input energy source and load make the converter suitable for renewable energy applications. Also, the proposed converter shares high voltage gain with low voltage stress on semiconductors (switches/diodes), improved compactness, and high efficiency. The operating principles and steady-state analysis of the proposed converter are illustrated. Then the theoretical efficiency analysis and performance comparison with other converters are discussed. Finally, a 200 W prototype with 380 V output voltage is established based on the design guidelines, and experimental results verify the accuracy of the theoretical analysis.