A novel maximum power point tracking in partially shaded PV systems using a hybrid method

Abstract

To exploit photovoltaic systems, a major point that merits attention is to find maximum output power for the efficiency increase. The output power of solar cells depends on the ambient temperature and intensity of solar radiation. The cloud phenomenon creates a partially shaded on solar arrays; in this condition, the power–voltage curve of a solar array has several local maximum points. When there is uniform radiation, conventional methods of maximum power point tracking (MPPT) can be used. However, these methods are not efficient in partially shaded, due to the existence of several Maximum Power Points (MPPs) in the power-voltage characteristic. In this paper, a novel method for MPP tracking under the partially shaded is proposed, which is a combination of observational tracking and constant–voltage methods. When there is uniform radiation, the tracking operation is observed and tracked by a fuzzy logic–based approach. The proposed method is based on the existence of a relationship between radiation intensity and MPP voltage. In the existence of this relationship, the MPP voltage can be calculated by measuring the intensity of radiation at any moment. In addition, partially shaded works using the constant-voltage method. To verify the simulation results, laboratory implementation was performed. The results show that with considering the MPPs, the output power increases about 10% while the partially shaded is applied.