Wide‐Input High‐Gain Three‐Port DC–DC Converter Based on Improved Quadratic Structure

ABSTRACT Aiming at the problems of low input voltage and wide range of new energy hybrid power supply systems such as photovoltaic and fuel cell, a wide‐input high‐gain three‐port converter based on improved quadratic structure is proposed. The three ports of the converter are connected to new energy power system, battery, and load, respectively, among which the flow of energy is realized. The improved quadratic structure can improve the voltage gain of the converter and reduce the voltage stress of the power switch by integrating the diode–capacitor voltage doubling unit into the quadratic structure. At the same time, the new energy port of the converter can achieve both boost charging and buck charging of the battery port, avoiding the voltage limit of the dual‐source port. The topology, working principle, and steady‐state characteristics of the proposed converter are analyzed in detail. The voltage conversion ratio of the converter is 3‐ d /(1‐ d ) 2 , and the working efficiency is 93.2%. In addition, the three operating modes of the proposed converter are modeled mathematically, and the control strategies under the three operating modes are designed. Finally, a 100‐W prototype is built to verify the effectiveness and correctness of the converter.