Mitigation of mismatch losses in solar PV system - Two-step reconfiguration approach

Photovoltaic system encounters with some limiting factors such as partial shading that reduces the power output. Partial shading is not predictable; not measurable; and unavoidable. A single partial shaded PV cell limits the power output of the unshaded PV cells connected with it in series. In this paper, a hybrid reconfiguration algorithm has been proposed. The 4 x 4 PV array has connected in Total Cross Tied configuration. The proposed algorithm performs reconfiguration in two steps. In the first step, the algorithm splits the 4 x 4 PV array into two sets of 2 x 4 PV arrays and it establishes the interconnection between the two sets by through the 2 x 2 switching matrix circuit in the second step. The interconnection will be executed based on the power generation of each row in the 2 x 4 PV arrays i.e., the maximum power generating row in the set 1 has connected with the minimum power generating a row in set 2. By this reconfiguration, the rows in the PV array can be made as even current generating rows. The proposed method suppresses the effect of partial shading in the power output also it reduces the required numbers of switches and the dimension of the switching matrix circuit.