A Cubic High-Gain DC–DC Converter for Improved Maximum Power Extraction in Partially Shaded PV Systems

This paper presents a high-gain cubic DC–DC converter designed for three-phase two-level grid-connected photovoltaic (PV) systems, offering enhanced performance under partial shading conditions. The converter achieves a cubic voltage gain using a single active switch and fewer passive components, with lower input current ripple and reduced voltage stress on semiconductor devices. A comprehensive steady-state and power loss analysis is presented to derive the converter’s high gain and efficiency. Here, a grid-current-based maximum power injection to the grid (MPIG) strategy is used instead of a traditional PV-side maximum power point tracking (MPPT), eliminating the need for PV-side voltage and current sensors. Further, the particle swarm optimization (PSO) algorithm is applied to track the global peak under partial shading conditions. The effectiveness of the converter and control strategy is demonstrated through experiments on a three-phase PV-grid prototype, tested with different array configurations and shading patterns. Experimental results show the proposed converter’s improved peak tracking, stable grid operation, and better performance under partial shading than the conventional boost converter, validating the proposed converter’s suitability for practical PV-grid integration.