An Adaptive String Interconnection Technique for Reconfiguration Optimization of PV Farm under Partially Shading Condition

This paper presents an adaptive string interconnection (ASI) method to improve a PV farm system under partial shading conditions. PV farms, that consist of a large number of strings encounter significant issues, such as deeply decreased of output power when facing partial shading circumstances. The proposed ASI method works to reconfigure the strings as well as the individual PV connections so that the output power is improved. A common series-parallel (SP) connection of strings is used as the initial setup of configuration. Every series string is equipped with a current measurement. The current is employed to observe the occurrence of partial shading. The string that has the lowest current is then connected to the other string which has the highest current. The individual PV panels in both strings are also connected in parallel. This results in an increased output power of the entire PV farm, compared to the SP configuration. Thus, the ASI technique can be an alternative technique to minimize power losses and the number of string interconnections.