Coupled Inductor Based Quadratic High-Gain DC-DC Converter With Wide Range of CCM Operation for Photovoltaic Applications

Abstract

This paper presents a novel DC-DC converter designed to achieve a high step-up voltage gain while maintaining a continuous input current. By incorporating a coupled inductor, the proposed converter achieves a high voltage conversion ratio. The continuous input current with minimal ripple makes this converter particularly suitable for a wide range of applications, especially in photovoltaic (PV) systems. The converter operates in continuous conduction mode (CCM) across a wide range of output loads, input voltages, and duty cycles. The use of a single power switch and gate driver circuit not only reduces costs but also enhances overall efficiency. The paper provides a detailed steady-state mathematical analysis of the converter and examines its operation in CCM, discontinuous conduction mode (DCM), and boundary condition mode (BCM). Additionally, an efficiency analysis is presented. To validate the converter's performance, experimental results are provided for a prototype with an input voltage of 20 V, an output voltage of 400 V, an output power of 235 W, and a switching frequency of 33 kHz. These results are thoroughly analysed to confirm the converter's effectiveness. Finally, the proposed topology is compared with other existing topologies to further evaluate its performance. For instance, at a duty cycle (D) of 0.5, the converter achieves a voltage gain of 20, demonstrating its superior step-up capability.