Research On Maximum Power Point Tracking Of The Photovoltaic Power Generation System Based On DSP2812

As a new type of green renewable energy, solar energy has large reserves, non-polluting, sustainable use, etc. Therefore, the use of solar energy is receiving increasing attention, and solar photovoltaic technology is the focus of widespread concern. However, the output characteristics of photovoltaic cells have a strong non-liner, and is influenced strongly by the external environment factor. Therefore, in order to fully take advantage of solar energy, the maximum power point tracking of photovoltaic power generation system is researched. At the same time the inverter control part is also studied.The status and prospects of the solar photovoltaic power generation at home and abroad is described. Second, as an overview of solar energy photovoltaic power generation systern,the solar photovoltaic structure of the main components, classification and application are researched.With reference to the general engineering mathematical model of photovoltaic cells, simulation model of photovoltaic arrays is built in MATLAB. Also established the simulation model of the control system based on the boost, and made the simulation under different light intensity, different temperature conditions, get different conditions power-voltage, current-voltage curves. Then several commonly used methods of maximum power point tracking are introduced. Maximum power point tracking simulation with disturbance observation and the fixed voltage combine with disturbance observation are studied, simulation results show the correctness of the theory, both methods can achieve the maximum power point tracking. But the fixed voltage method combined with perturbation and observation method, no matter on the dynamic performance and steady state performance is greatly improved.Inverter part of photovoltaic power generation system is studied, with intelligent power module IPM as the main circuit of inverter, pulse width modulation in inverter switch tube on SVPWM modulation technology is adopted.The hardware experimental platform of two levels photovoltaic power generation system is built.TMS2812is used the core of controller of the hardware platform. The hardware system include boost chopper circuit, inverter circuit, drive circuit, detection circuit and protection circuit. According to the control algorithm of the system, the software program is designed, including the main program of system, mppt program, the interrupt subroutine, and functional of each subprogram, provides software support for the experimental platform debugging.This paper uses perturbation observation method for maximum power tracking experiments, the experimental results show the control algorithm is accurate and reliable. This algorithm can make the solar cells working at maximum power point. In addition, the independent photovoltaic power generation is studied, the power distribution of the whole process from the photovoltaic panels to the inverter output is measured. This experiment for the grid-connected of photovoltaic power generation system laid the foundation.