Photovoltaic Cells Output Maximum Power Point Tracking Strategy Research And Design

In the face of the serious depletion of resources and the deteriorating environment,people pay more and more attention to the development and utilization of new energy.In many new energy sources, solar energy because of its unique advantages become the focus of development in the world. Photovoltaic power generation is an effective way to use solar energy, it is the solar energy through the photovoltaic cells directly into electrical energy. In real life, the conversion efficiency of photovoltaic cells can not meet the expectations of people, which requires the output power of photovoltaic cells as much as possible to maintain the maximum power point. As a result,a wide variety of controllers have been designed for maximum power point tracking. Different controller methods have their own advantages and disadvantages, the choice of parameters will also affect the tracking speed and tracking accuracy. Photovoltaic batteries are often connected to the grid system,where the load is often a sinusoidal change in the AC power supply, which the maximum power point tracking will have a certain impact. To this end, this thesis completes the circuit modeling and designs a double closed loop control strategy to overcome the load voltage perturbation to achieve robust tracking of the maximum output power of the PV cell.Firstly, the working principle of the photovoltaic cell is introduced briefly. The model of the photovoltaic cell is established and the simulation software is simulated.The output characteristic of the photovoltaic cell is analyzed in detail. Then, the composition of the photovoltaic power generation system is briefly introduced, and the chopper circuit is discussed. The parameters in the system are designed,and the principle of maximum power point tracking is described. Then, several commonly used maximum power point tracking methods are briefly introduced. The influence of parameter selection on the tracking of maximum power points is discussed in detail by using perturbation observation method. In real life, photovoltaic cells are often connected to the grid system, where the voltage at the load will become unstable, it will fluctuate in sine. At this time,several of the most common power point tracking methods will become very good,which requires us to adopt a better strategy to track the maximum power point.Finally,this thesis uses a double closed-loop control method to solve this problem.The inner ring uses the PID control reference voltage, the outer ring to adjust the output.In this thesis, we use the system application circuit to establish the average model.Simulink in the simulation, compared with the disturbance observation method,proved the superiority of this method.