The Research Of The Stand-Alone Photovoltaic System And It's Maximum Power Point Tracking (MPPT)

With the development of photovoltaic (PV) technologies, applications of photovoltaic have grown rapidly, indicating that the photovoltaic are attractive to produce environmentally benign electricity for diversified purposes. In order to maximize the use of solar energy, this thesis focuses on the PV power generation systems, which includes modeling of PV systems, maximum power point tracking (MPPT) methods for PV arrays.The modeling of PV arrays is the base of research on PV systems. This thesis presents simulation model of PV arrays based on the output characteristics formulas. It can be directly applied in circuit simulation and system analysis.Maximum Power Point Tracking (MPPT) method is an important means to improve the system efficiency of PV power generation system. MPPT theory and various MPPT algorithms are introduced in the literature. Furthermore, this article analyzes the principle of boost circuit and impedance transformation characteristic in stand-alone PV system with MPPT technology applications. The simulation study of boost circuit applied in the MPPT is completed based on Simulink simulation model. Based on those researches, this thesis proposes a novel implementation of an adaptive duty cycle P&O algorithm that can reduce the main drawbacks commonly related to the traditional P&O method, at the same time, the simulation results verify that the novel MPPT algorithm can track PV array's MPP efficient, even under the circumstance of isolation level, ambient temperature changing rapidly.