An Auto Tuned MPPT Method for Solar PV Array under Varying Irradiance

The extraction of maximum power from solar PV array under varying environmental conditions require a robust control technique for DC-DC converter. Most widely used classical maximum power point tracking (MPPT) techniques such as perturb and observe (PO) and Incremental Conductance (INC) have some problems related to power oscillations and poor convergence due to fixed step-size. This paper presents an auto tuning methodology to address the aforementioned issues during maximum power tracking. In order to achieve this objective, an exponential variable step selection is developed and the duty ratio as produced by the proposed MPPT method is fed to DC-DC Boost converter. Such arrangement not only reduces the oscillations near maximum power point but also optimizes the convergence speed as found in fixed step size methods. The proposed technique is developed in the Simulink environment of MATLAB software and tested for both steady-state and dynamic conditions. The tested results are better than their classical counterparts.