Global maximum power tracking algorithm for solar photovoltaic array under uneven illumination

Abstract

Based on the analysis of the shortcomings of the existing maximum power point tracking (MPPT) method, a multi-peak MPPT tracking strategy is proposed based on the geometric characteristics of the output curve of photovoltaic array. This method takes advantage of the fact that the pv array U-I output curve has the characteristics of "the left slope changes slowly and the right slope changes quickly" at the local extrema point, quickly locates the voltage interval including the global maximum power point, and converts it into a perturbation observation method (perturb and observe, P&O) with higher tracking accuracy within this interval. Thus, the global maximum power point can be tracked. By comparing this algorithm with improved disturbance observation (Perturb, observe and check, POC), its application range was determined and applied flexibly. The algorithm is fast and can avoid missing peak value effectively.