Akademik Veri Yönetim Sistemi
ENERGY HARVESTING AND ENERGY EFFICIENCY: TECHNOLOGY, METHODS, AND APPLICATIONS, cilt.37, ss.261-292, 2017 (SCI-Expanded)
Photovoltaic modules have nonlinear current-voltage (I-V) characteristics. Thus, output power of the photovoltaic module varies with module specification and its operation point. It means that, the photovoltaic system generates maximum power at a single operation point for an environmental condition such as the irradiation level and angle, ambient temperature level etc. In addition, energy conversion efficiency varies with load level and operation point of the photovoltaic system. Since these parameters are variable, operation point of the photovoltaic system should be controlled to get maximum output power and maximum energy conversion efficiency. This action is called as maximum power point tracking. The maximum power point tracking action is usually performed with a power electronics converter. A number of maximum power point tracking methods have been introduced to obtain fast response, especially in rapidly-changing atmospheric conditions, low oscillation and higher energy conversion efficiency values. However, most of these methods are effective for uniform solar irradiation conditions. If the solar irradiation is non-uniform, the power-voltage (P-V) curve of the photovoltaic module or array has multiple peak points: Several local maximum power points and one global maximum point. In this case, traditional maximum power point tracking methods determine the nearest peak power point, which may be a local maximum point. Thus, some improved maximum power point tracking methods have been proposed to determine the global maximum power point of the photovoltaic system even under partial shading conditions. A discussion on different maximum power point tracking methods for the solution of these problems will be given and the most powerful techniques in the literature will be outlined.