Peak prediction method of maximum power point for series-parallel photovoltaic array under partial shading condition

Abstract

To achieve optimal energy extraction from photovoltaic array during partial shading (PS) condition, a maximum power points tracker (MPPT) with good performance is highly demanded. One of the main criteria of a good MPPT is the accuracy to track the maximum output power with minimal time. Therefore, few equations are proposed by the researchers to predict the peak voltage (V lp ) of PV array during PS occurrences. The equations basically claim that it can assist to improve the tracking efficiency and speed by predicting the maximum power point (MPP). But, it never was proved that those equations are valid for all PS patterns that can be occurred. Considering the above fact, this paper focus on analyzing the credibility of two maximum power point prediction methods namely (1) 0.8 Voc method and (2) improved 0.8 Voc method. Test performance is carried with five shading patterns of 5×4 series-parallel (SP) configuration of PV array. Results confirm that the equation is only valid for the shading that has similar irradiance level, for each of the strings inside the PV array.