Performance Assessment of an Electrically Reconfigurable Photovoltaic Array in an Off-Grid System

Partial shading of photovoltaic (PV) modules reduces the output power of a PV system. Electrically reconfigurable arrays have been proposed to increase the power output of shaded PV systems. In this paper, an electrically reconfigurable PV array was built using the total cross-tied (TCT) topology. The PV array was then tested manually using different shading patterns. Furthermore, the PV array was deployed and allowed to autonomously reconfigure in an environment where shading due to clouds and foliage is expected. Results from the I-V and P-V curves of the PV array show that the power improvements expected of the array after reconfiguration were met. However, when connected to the balance of system components, improvements in the power output were not met. During pilot deployment, the speed of changing shading patterns also affected the outcome. Thus, when designing a PV system that incorporates a reconfiguration of PV modules, the following need to be considered: first, identify the potential causes of partial shading at the target location, which include the expected shading patterns and speed of changing patterns, and second, investigate the effects of the balance of system components, such as component efficiencies, speed of maximum power point tracking, and system type.