The Research Of High Accuracy Method Of Sun-tracking In Photovoltaic System

Today the traditional fossil energy is increasingly dried up. The solar energy has an enormousdeveloping application capacity as one kind of green renewable energy source which can be continuouslyused forever. Our country has made rapid development in the field of solar energy photovoltaic powergeneration during ten years. But our P-V power generation has a disadvantage of high cost, low efficiencyand backward technology. A new method is proposed in order to improve the utilization rate of solar energyand reduce the cost of P-V power generation. This method not only overcomes the shortcoming ofphotoelectric tracking vulnerable to weather conditions affecting, but also solve the problem about sunangle tracking accumulated error which can not eliminate. The system has advantages of simple structure,low cost, high tracking accuracy and very high practical value.By the comparison of some common sun tracking algorithms simulation, a mixed practical highaccuracy algorithm is proposed. A special four-quadrant solar cell is designed to correct the error of sunangle tracking so that the sun can be tracked precisely. When the tracking begins, first use the sun angletracking method to identify the position of the sun, and then use the photoelectric tracking method to trackthe sun accurately in little scope.Through the implementation of functional analysis of control system, the thesis completedhardware and software design of the tracking device. Include: MCU interface circuit design, opticaldetector circuit design, control and implementation component design and the software design ofelectro-optical tracking and sun angle tracking module. The simulation and experimental results show thatthe system can meet the design requirements completely, can track the sun all-weather automatically andaccurately and can improve the efficiency of photovoltaic power generation.