Analysis of a distributed maximum power point tracking tracker with low input voltage ripple and flexible gain range

摘要

Partial shading effects on series-connected solar cells (modules) motivate the development of distributed maximum power point tracking (DMPPT) technology. This study reviews three dominant DMPPT architectures with preference given to DMPPT tracker technology based on its modularity, gain flexibility and technical maturity for decades of development. Topologies suitable for DMPPT tracker application are investigated. A modified buck–boost converter with reduced input voltage ripple and flexible-gain range is adopted for DMPPT tracker application. At steady state, the topology can reduce the power oscillation at maximum power point and improve the tracking accuracy without increasing input filter capacitor. The flexibility in gain range makes it well-suited for many commercial solar energy harvest systems under rapidly varying temperature and illumination conditions. The simulation and experiment of a 15 W low-power prototype under small voltage scale confirm the feasibility of the proposed converter.