Dual-axis Solar Tracking System

Energy shortage is a problem difficult to avoid in the future, non-renewable energy resources are depleted, the development of renewable energy sources is imperative. At present, the efficiency of solar energy utilization is not high. In the utilization of solar energy equipment, if a plane perpendicular to the sun to receive the incident light, so that you can collect more solar energy per unit area. Practice shows that, under the same conditions, compared with fixed power generation equipment, the PV array with automatic tracking device energy increased by more than30%. The system is mainly used in solar power generation equipment, consist of mechanical parts and control system.Mechanical parts is a solar tracker in two-dimensional horizontal and vertical movement of the head, including the chassis, option of transmission mode, the design of the internal structure. By the sensor, the controller sends a signal to the horizontal drive motor, through a gear transmission, to achieve a horizontal orientation of the solar tracking; in the vertical plane,stepping motor drive gear, worm gear to achieve a solar cell panel in the vertical direction rotates up and down, to achieve two direction of the solar tracking operation with the stepping motor1.Control part of the design includes light intensity, sun position sensor module, AD converter, microcontroller systems and stepper motor parts. On the basis of analysis of several major tracking mode, the system uses the photoelectric detection tracking mode to achieve the solar tracking, and light intensity sensors to determine whether to start the tracking system. In this paper, solar silicon cells as a photosensitive element is used to detect light intensity, the sun azimuth sensor use photoresistor as photosensitive devices, the same photosensitive resistor is placed in the four directions of the two panels. When both ends of the photoresistor received light intensity difference reaches a certain value, after comparing operational amplifier circuit into the microcontroller to achieve motor movements, intermittent solar tracking.In order to reduce power expenditure,when the light intensity reaches a certain value starts tracking;below the experimental setting stops the tracking;continues to wait for comparing the system to reduce losses caused by frequent movements.By comparing the daily average sampling of eight days tracking and non-tracking solar light intensity by using MATLAB integral, the experimental results show the effectiveness of the system.