A New High Voltage Gain Common‐Ground Step‐Up DC‐DC Converter Integrating Coupled‐Inductors and Switched‐Capacitors

Abstract

ABSTRACTThis study proposes a new high‐voltage gain quadratic‐structured common‐ground step‐up DC‐DC converter, integrating coupled‐inductors and switched‐capacitors. This configuration achieves a significant voltage gain without necessitating either a substantial duty cycle or an elevated turn ratio in the coupled‐inductors. A critical innovation is the embedding of the secondary windings of the coupled‐inductors into the switched‐capacitor cell, which not only enhances voltage gain but also effectively suppresses the inrush current typical in such cells. The converter's features include the successful recycling of energy from the leakage inductors; low voltage stress exerted on power switches; zero‐current switching (ZCS) turn‐on of the main switch; ZCS conditions for the diodes' turn‐off; reduced switching losses because of the application of a quasi‐resonant (QR) operation between the leakage inductors and middle capacitors; simultaneous operation of the power switches; continuous input current; a wide duty cycle range; and a common‐ground output–input connection. The operating principle, steady‐state analysis (CCM and DCM), design considerations, efficiency calculation, small‐signal modeling with controller design, and comparisons with other related converters are provided. Finally, experimental results from a 100‐ to 300‐W prototype with 20‐ to 30‐V input and 400‐V output are given to validate the proposed converter's theoretical analysis and feasibility.