Sunlight Illumination System By Automatic Solar-tracking

As renewable energy, solar energy has the advantages of environment-friendly and sustainable for utilization. During the process of solving the traditional energy crisis, many countries focus their eyes on exploitation and research of solar energy. Lighting energy consumption is one of the most building energy consumption, which accounts for about30%of total building energy consumption. So if we can transmit sunlight into the dark place, it will not only greatly reduce the lighting energy consumption but also benefit people’s physical and mental health, as people will be able to enjoy the pure and natural sunlight without going outside. Studies have shown that the energy acceptance rate of solar equipment between tracking and non-tracking mod for sunlight’s movement is37.7%. EU has turned85%of nearly ten years researching on solar energy heating and budget for growth to sunlight illumination research. But for our China, it’s just an beginning.By analyzing the principle of the solar-tracking devices in nation and oversea, this paper presents a set of sunlight illumination system by solar-tracking. The system adjusts the tracking axis separately according to the solar elevation angle and azimuth angle, the PLC evaluates the pulses to control the rotation angle of the stepper motor, and it realize the automatic solar-tracking.Based on the solar position geometrical model, this paper has set up the two-axis solar-tracking motion control equation of the sun moving trajectory tracking on the method of vector analysis, and analyzes the motion characteristic and done the systematic theoretical research and simulation on the intermittent tracking control method.The hardware part of the system, we have chosen the S7-200series PLC as the core controller, two86BYG250DS stepper motor and SD20806stepper motor driver. The software part of the system, it has completed the software design work which includes the main program module, solar angle calculation module, and stepper motor pulse control module as well as other functional modules of the system based on the STEP7-Micro/WIN32programming software platform.Finally, I will do the job that debug software and hardware to achieve the original design concept, which proves that the research thought and the control methods as well as the hardware and software design of the tracking control system this paper has designed are indeed feasible. This system has a simple structure, it runs smoothly, the tracing precision is high,the stability is high and so on.