Study Of The Automatic Sun-tracking System

In solar power generation, the angle of the battery plate facing sun and sunlight is a key factor determining the efficiency of solar power generation. To find a sun-tracking way with little cost and high precision, this thesis proposes a mechanical system, with one-dimension driving and two-dimension tracking, and studies the sun-tracking ways using Single Chip Microcomputer (SCM) to control step motor.This thesis first analyzed the necessity of sun-tracking system, followed by a theoretical calculation and analysis of solar declination angle and solar hour angle of equatorial coordinate, and solar elevation angle and solar azimuth angle of horiziontal coordinate. A theoretical analysis was also made of two sun-tracking ways. On the basis of the sun-tracking characteristics, a mechanical transmission system, with one-dimension driving and two-dimension tracking was put forward. The tracking strategy using SCM to control step motor was brought out, the control system designed, and simulation taken to verify the designing. To meet the requirement of control system, SCM AT89C51 was chosen as the intelligent unit. To complete the functions with AT89C51, the thesis focused particularly on the design of peripheral circuit of the SCM and relevant software. The production method of four-quadrant photocell and the relevant circuit and its working principles were introduced. The driving method for step motor with the use of double axises was also introduced in this thesis.The result of analysis and design indicates that the method meets the requirements of sun-tracking system.