Research and Improvement of Maximum Power Point Tracking for Photovoltaic Systems

In this paper, the advantages/disadvantages of several commonly used maximum power point tracking algorithm (Perturb & Observe, Incremental Conductance, Three Points Weighting, and Improved Perturb & Observe) are firstly discussed. Then, a Modified Perturb & Observe (MPO) method is proposed to achieve maximum power point tracking (MPPT) for a PV (photovoltaic) system and to improve the shortcomings of prior methods. The MPO method possesses a conveniently regulated capability of the perturbation, and stopping perturb while tracking to near the maximum power point. Such features can improve the power consumption problem of traditional Perturb & observe (PO) method in the maximum power point, while also increasing the speed of maximum power tracking to increase the system dynamic response. In order to verify the effectiveness of the proposed MPO method, a 120W PV system will be established, the MPO method and the others MPPT methods is used, respectively and compared. Finally, simulation and experimental results will be presented to verify the feasibility of the MPO algorithm.