A New Quadratic High Step-Up DC-DC Converter Based on Coupled Inductors for Renewable Energy Applications

This paper presents a high-step-up DC-DC topology. This circuit configuration yields a quadratic output voltage while maintaining low voltage stress on power MOSFETs. The configuration features a common ground connection among the input and output ports, with the sources of the switches directly linked to the ground. It has two switches, three diodes, four capacitors, and two coupled inductors. The first coupled inductor has three windings to increase voltage gain and limit input current ripple. The second one has two windings to increase voltage gain. Steady-state analysis is conducted to determine output voltage and voltage stress across power MOSFETs. The suggested topology’s key feature is its soft input current ripple, which is achieved using a coupled inductor configuration. A comparison section highlights its features compared to the state-of-the-art topologies reported in this paper. In addition, graphical voltage gain and voltage stress of power MOSFETs compared with other structures are added. The final step includes the development of a laboratory prototype, which operates under duty cycle variations of 0.3-0.6 for a wide input voltage range of 18-48 V. The prototype is tested for a maximum output power of 400W and a switching frequency of 50 kHz.