High step‐up DC–DC converter with three‐winding‐coupled‐inductor and output capacitor in series for clean energy

Abstract

A novel high step-up DC-DC converter with a three-winding-coupled-inductor and an output capacitor in series is proposed in this study. By charging for two windings of dotted terminal connection in series by input source, the proposed converter can achieve a higher gain by using smaller turns ratios when the active switch is turned on. The passive clamping circuits are introduced for not only recycling leakage energy but also alleviating voltage spike on the main switch effectively. Meanwhile, the reverse-recovery problem of the diode is alleviated by the leakage inductor. Thus, the efficiency can be improved. In addition, output capacitors are in series to provide energy so that the volume of the output capacitor is reduced. The operating principle and steady-state analyses of the proposed converter are discussed in detail. Then, the performance of the proposed converter is compared with existing converters. Finally, a prototype circuit is built with a 40-V input voltage, 380-V output voltage, and 400-W output power to verify the performance of the proposed converter.