Reconfiguration strategies for reducing partial shading effects in photovoltaic arrays: State of the art

Power delivered by a Photovoltaic (PV) cell reduces significantly due to non-uniform irradiance. Consequently, in the case of PV module or array, the generated output power get reduces and further deteriorates the overall system performance. The reduction of output power is not directly proportional to the shading area but depends on the shading pattern and type of array configuration chosen. Many solutions have been reported in the literature to reduce partial shadings. However, the reported solutions may fail to enhance maximum power to the possible extent. Therefore, to compensate these power losses a promising technique is required which relies on reconfiguration strategies, namely reconfigure the PV modules within the PV array in order to increase maximum power at a higher level. These strategies are classified into dynamic and static reconfiguration techniques. This paper presents the state of the art of reconfiguration strategies for PV array's to increase maximum power under partial shading and mismatch conditions. In addition to this, the challenging issues for hardware implementation of both dynamic and static reconfiguration techniques are discussed in this paper. Based on the review study, it can be concluded that the dynamic reconfiguration techniques are relatively expensive, but this can effectively compensate the partial shading and mismatch effects in PV array as compared to static technique.