Improved maximum power point tracking algorithm for photovoltaic sources

The photovoltaic generator exhibits a non-linear i-v characteristic and an intermediate switch-mode DC-DC converter is required to extract maximum power from the array. A boost converter is used, in this paper, to track maximum power from the photovoltaic source. Mathematical analysis and desirable steady-state conditions of the converter are derived to give satisfactory maximum power point tracking operation. The tracking performance depends on the type of algorithm used. In this paper a variable incremental duty ratio algorithm is proposed to reduce the tracking time and to improve the tracking performance. In this algorithm duty ratio is high at starting and it follows a geometric progression in the subsequent iterations. Proposed concept is verified experimentally and also compared with the conventional perturb and observation method.