Dispersed partial shading effect and reduced power loss in a PV array using a complementary SuDoKu puzzle topology

Abstract

A complementary SuDoKu puzzle (CSDKP) topology for the circuit configuration of photovoltaic (PV) arrays under partial shading conditions (PSCs) is proposed in this research. Modified from the total-cross-tied (TCT) configuration, the connection and physical location of the modules in a PV array are rearranged based on the complementary SuDoKu puzzle patterns so as to distribute the PSC effects over the entire array. In addition, to mitigate the common corner-shading patterns in a PV array, which are typically caused by the direction of the sunlight or mutual module shadings, the proposed topology makes use of an especially-designed complementary diagonal circuit arrangement. For the purpose of validation, six PSC cases are considered, and the output of a PV array configured using the proposed CSDKP topology is evaluated and compared with four other topologies. The evaluation results demonstrated that the CSDKP offered the lowest averaged power loss (12.86%) and the highest averaged maximum-power improvement (14.6%) among the five topologies. The advantages of the proposed method include easy implementation with simple rules, simplification of the P-V curves, and a reduction in the cost of maximum power point tracking. In addition, two novel performance-evaluation indexes are proposed in this study for the performance comparison of the topologies. Based on the evaluation results, with respectively calculating the current differences and roughly estimating the group module power losses, the two proposed indexes approximately evaluated the power loss of a PV array with high correlation coefficients (r2 = 0.9655 and 0.9590).