Research Specifications

This paper presents and investigates a high step-up non-isolated DC-DC converter with an integrated transformer for photovoltaic applications. Unlike most non-isolated DC-DC converters that rely on coupled inductors, the proposed converter uses an integrated transformer combined with a modified voltage multiplier cell to achieve a high voltage conversion ratio. Additionally, a passive voltage clamp is employed to reduce voltage stress across the switch and recycle energy stored in the leakage inductance of the integrated transformer. This approach allows for the use of a switch with low on-resistance (RDS-ON). Other notable advantages of the proposed structure include continuous input current with low ripple and a shared common ground between the input source, switch, and load, making it an attractive solution for photovoltaic-based systems. The relatively low voltage across the diodes also mitigates reverse recovery issues. The proposed topology is derived from the SEPIC converter and is studied in detail. Furthermore, the proposed configuration is compared to various previously presented DC-DC converters to demonstrate its advantages. Finally, a 250-W laboratory prototype is developed, and experimental results are presented. These results validate the theoretical analysis and confirm the functionality and feasibility of the proposed converter.