Enhancing the tracking techniques for the global maximum power point under partial shading conditions

The partial shading is one of most critical problems facing the Maximum Power Point Tracking (MPPT) techniques for photovoltaic systems. This paper provides a review of challenges and opportunities regarding the problem of partial shading. In addition, it introduces a new technique for tracking the Global Maximum Power Point (GMPP) under different Partial Shading Conditions (PSC). The technique utilizes a two-stage algorithm to accomplish the tracking process efficiently. In the first stage, it applies a Genetic Algorithm (GA) to get the nearest point to the GMPP. In the second stage, it utilizes a new and fast MPPT algorithm to search for the target GMPP starting from the nearest point fetched in step one. In order to evaluate the new technique, a complete microcontroller based prototype is implemented and tested. The experimental results show that the new technique reaches directly to the GMPP in very short time and with limited steady state oscillations. Accordingly, the new technique has a significant improvement in energy extraction efficiency from the photovoltaic array to the load.