A high step-up DC–DC converter with voltage multiplier cell for renewable energy systems
This paper proposes a novel high step-up DC–DC converter topology featuring two synchronously controlled power switches driven by identical gate signals, thereby simplifying the control circuit. The proposed converter (PC) employs an input inductor to ensure continuous input current and a three-winding coupled inductor to achieve ultra-high voltage conversion gain. In addition, a voltage-multiplier cell is incorporated to further enhance the output voltage gain (VG). A passive-clamp circuit is utilized to recycle leakage energy, reduce voltage spikes, and improve overall efficiency. The converter is analyzed under both continuous conduction mode (CCM) and discontinuous conduction mode (DCM), including the derivation of VG characteristics and CCM/DCM boundary conditions. A comprehensive theoretical investigation is presented, covering steady-state operation, VG, voltage and current stresses of semiconductor devices, component design considerations, power-loss analysis, small-signal modeling, control design, and dynamic response characteristics. Compared with recently reported high step-up converters, the proposed topology achieves an improved trade-off among VG, switch stress, magnetic complexity, and component count through the coordinated integration of the coupled-inductor structure, voltage-multiplier cell, and passive-clamp circuit. To validate the theoretical analysis, a 200 W laboratory prototype with a 24 V input and 400 V output was designed and implemented in both simulation and hardware. Experimental results demonstrate a peak efficiency of 96.7% at 40% load and 95.7% at full load, confirming high efficiency over a wide operating range. These results verify the effectiveness and suitability of the PC for renewable-energy and high step-up power-conversion applications.