New High Step-Up Two-Stage DC-DC Converter With Two Coupled Inductors and Switch Capacitor
This paper presents a high-step-up DC-DC converter suitable for low-voltage source applications, such as renewable energy systems. The proposed topology integrates a two-stage structure, two coupled inductors with dual windings, and a voltage lift technique to achieve high voltage gain, continuous input current, and reduced semiconductor device voltage stress. The converter features a common ground between the input and output sides, which facilitates system integration and control. The input current is divided between the two coupled inductors, thereby limiting losses in the input-side components. Steady-state analysis of the converter was performed to determine the voltage gain, voltage stress, and component currents. Relationships relevant to the converter's design have been presented to facilitate its operation under the required conditions. Additionally, small-signal analysis was conducted to support the controller design, and the corresponding transfer functions were derived. The converter's power losses have also been calculated. Afterward, a comparison is presented between this structure and other designs in the literature to identify its advantages and disadvantages. To validate the theoretical analysis and practical feasibility, a 100-W prototype with a 200-V output voltage was implemented. The experimental results show good agreement with the theoretical predictions.