Automatic Tracking Photovoltaic Power Generation Based Embedded Control System Design

In order to solve the energy crisis and ecological environment deterioration and realize the sustainable development, photovoltaic (PV) power generation has been regarded as the key of the development of new energy and renewable energy all over the world. However, a bottleneck in the current application of PV power is the low efficiency of power, which largely restricted the P V power generation applications and development. A kind of important way to improve the efficiency of PV power generation is to design automatic tracking system of the PV modules. That is, for receiving maximum limit energy, some control means is used to make the sun light ray perpendicular incident to solar panels as far as possible.From the perspective of engineering application practice and common features of multiple types of tracker, two representative types including plate dual-axis tracker and tilted single-axis tracker, are selected. In this thesis, a common automatic tracking control system is designed based on embedded technology. The main content of this thesis are summarized as follows:Firstly, based on the calculation of the sun trajectory model, the motion characteristics of the solar tracking system are analyzed and the movement equation is established in the flat earth coordinate. As for the defects and shortcomings of the existing tracking control method, an improved the intermittent tracking method is proposed; moreover, the feasibility is demonstrated by the theoretical analysis and the simulation results. In the meantime, a control method of tilted single-axis tracker flatting to the wind is presented to solve the problem of poor wind resistance of tilted single-axis tracker.Secondly, in the overall design of control system, based on the common mode of trackers' movement, the design of tracking control system is divided into two parts of the tracking controller module and axis controller module. And a "pyramid" structure of the control system is proposed for group control of multiple types of tracker.Thirdly, during the process of hardware design which based on the overall design, hardware structure and schematic diagram of the tracking controller and axis controller are designed in a modular approach. Besides, the embedded real-time systemμc/OS-Ⅱis introduced to the software design and its transplant on ARM7 is realized. Software design of tracking controller is divided into task that improved the stability and efficiency of the control system, aiming at to reduce the exploration costs. In the last part, debugging of engineering application is completed with the PC software. The present picture and data curve demonstrates the good operating results for the tracking control system designed in this thesis. Meanwhile, experience in design and engineering application of the tracker is summarized.