Investigation of pil based maximum power point tracking system with diffrent shading patterns and photovoltaic connection types

Increasing the number of the Maximum Power Points (MPPs) on the PV array characteristic deteriorate the performance of the MPPT algorithms. Additionally, the connection types of the PV panels and the pattern of partial shading can also increase the number of MPPs and can change the shape of the characteristics curve of the PV array. Therefore, it is highly important when installing a PV array the type of the PV panels connection, the MPPT algorithm to be employed and the partial shading patterns. This study tests the most commonly used three MPPT algorithms and eight different connection types on a Processor-In-Loop (PIL) platform using a TMS320F28335 DSP kit under five partial shading conditions (PSCs) with a 5x5 PV array. According to the PIL results and analysis, among the given connection types, the Total Cross Tide (TCT) type connection provides the highest array output power under all PSCs. It reaches its peak value under the diagonal (DG) shading patterns. Also, it has a maximum Fill Factor (FF) of 65.73% and a minimum Mismatch Power Loss (ML) of 10.40%. Additionally, under almost all test conditions (3 of 48 tests are excluded), the PSO algorithm reaches the Maximum PowerPoint (MPP). However, in many conditions (35 of 48 cases), the three employed algorithms have the same performance. All these results show that for the power efficiency of the PV system, not only the MPPT algorithms are important, but also the connection types, partial shading patterns, and their evaluation together are of great importance.