华北科技学院
摘 要
以常规能源为基础的能源结构随着资源的不断的消耗，将越来越不适应可持续能源的发展的需要。加速开发以太阳能为主体的可再生能源以成为人们的共识。太阳能作为一种作为一种清洁能源，倍受人们重视。精确跟踪太阳，对太阳能利用率的提高是显著的，市场上急需一种高精度，高稳定性的跟踪控制器。 跟踪太阳的方式主要有光电跟踪和视日运动轨迹跟踪。光电跟踪主要控制过程是：由光敏传感器采集太阳与光伏电池板之间水平与垂直方向的位置偏差信号与光强信号，并反馈给数据处理器与控制器，经过数据的处理与放大，发出驱动信号，经过驱动电路控制步进电机的转动，经过减速机构缓慢调整角度。视日运动轨迹跟踪将太阳位置受时间、季节、所在地区经维度等因素综合考虑。 本设计采用光时互补的跟踪方法，即是以视日运动轨迹跟踪为粗调，从时钟模块读出当前时间计算出太阳的空间位置，并根据经纬度进一步计算出太阳的方位角和高度角。由单片机发出驱动信号控制步进电机转动，到达指定位置。先大致定位太阳的位置。当转到既定位置之后再采用光电跟踪方式，精确定位。这样可以互相弥补不足。为完成本设计，本文对跟踪方式进行了深入的研究，并在此基础上主要采用CDS光敏电阻，STC12C5A单片机与步进电机完成跟踪器的设计。首先根据设计要求和指标，提出系统的设计方案并确定方案性原理上的可行性。根据要求和各个模块的功能，完成主要器件的选型。在硬件系统设计的基础上，使用汇编语言完成软件程序的程序编写。最后，论文还对整个课题设计进行总结，并对课题中存在的问题提出了改善措施和进一步完善本系统的建议。 主要工作包括以下内容：
（1）设计太阳能电池板自动跟踪的电路原理图;
（2）设计单片机的外围电路，光电转换电路，步进电机驱动控制电路; （3）设计整个系统的电路原理图;
（4）软件的设计：使用C51语言实现了单片机的控制程序设计;
关键词： 光电跟踪;视日运动轨迹跟踪;光敏电阻;单片机
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太阳能电池板自动跟踪系统设计
Abstract
As the consumption of natural resources based on conventional energy sources in energy structure, it will not become more and more able to meet the requirements for sustainable energy development. It becomes our common views to accelerate the exploitation of the solar energy which is the the main body of the renewable energy. As a kind of clean energy, the solar energy is becoming much appreciated. Therefore, tracking the sun precisely is significant to improve the utilization rate of solar energy and the market need a high-precision, high stability tracking controller.
There are mainly two ways to track the sun , including tracking the sun by photosensitive sensor and tracking the sun’s trajectory. The process of tracking by sensor is mainly : the sensor receive the signals which are the position discrepancy between the sunlight and the solar panel，in other word ,that is the position of the horizontal and vertical direction deviation. And feedback to the data processor and controller, then process the data and amplify , output driving signal . At last ,through the rotation of the stepper motor controlled by driving circuit and reduction box , it just adjust the angle until the sunray is completely perpendicular to the solar panel. The sun trajectory tracking mode is made ,given some other comprehensive factors such as time, season ,latitude and longitude .
This design use both tracking methods which are complementary . In other words ,it depends on the trajectory tracking for coarse adjustment ,which locate the sun. When it rotate on the setting position ,it will activate the photosensitive sensor to adjust the panel’s position accurately. And it can offset the both imperfections . To complete this design, this paper makes a deep research . And on this basis, we mainly use the Photosensitive resistance-CDS ,STC12C5A and stepping motor to complete the design of the tracker.First of all, according to the design requirements, we put forward system design plan and determine the feasibility of the project in principle. According to the requirements and function of each module, we complete the selection of main device. On the basis of the hardware system,use the assembly language to complete this programming. Finally, the paper summarizes the whole
II
华北科技学院
project design, and puts forward improvement measures on the problems existing in the subject and suggestions to improve.
Main work includes the following contents:
(1) Design Automatic tracking solar panel of the circuit diagram;
(2) Design the MCU peripheral circuit , photoelectric conversion circuit, stepper motor drive control circuit;
(3) Design circuit diagram of the entire system;
(4) The design of the software: use C51 language to realize the control program design by single chip microcomputer ;
Key words: sun tracking of using photosensitive sensor ; sun’s trajectory tracking ; Photosensitive resistance; Single chip microcomputer
III
太阳能电池板自动跟踪系统设计
目录
摘 要....................................................................................................................... I Abstract ................................................................................................................. II 第1章 绪论.......................................................................................................... 1
1.1 太阳能电池板自动跟踪系统设计的背景及意义................................ 1 1.2 太阳光自动跟踪系统的国内外研究现状............................................ 2 1.3 项目研究的主要内容及预期目标........................................................ 5 第2章 太阳能电池板跟踪相关理论研究.......................................................... 6
2.1 太阳的运行规律.................................................................................... 6
2.1.1 太阳高度角，方位角及时角介绍 .............................................. 6 2.1.2 太阳高度角及方位角计算公式 .................................................. 6 2.1.3 太阳能电池板跟踪参考坐标系 .................................................. 8 2.2 光伏电池的特性分析............................................................................ 9
2.2.1 光伏电池的光伏效应 .................................................................. 9 2.2.2 温度对光伏电池输出特性的影响 .............................................. 9 2.2.3 太阳的光照强度对光伏电池转换效率的影响 ........................ 10 2.2.4 光伏电池的I-V和P-V特性曲线 ............................................ 11
第3章 太阳能跟踪系统的控制目标与控制方案............................................ 12
3.1 控制方案选择...................................................................................... 12 3.2 控制方案设计...................................................................................... 13
3.2.1 光敏电阻设计的传感器 ............................................................ 13 3.2.2 跟踪控制系统整体原理框图 .................................................... 14 3.2.3 太阳能自动跟踪装置设计 ........................................................ 15
第4章 电池板跟踪系统硬件设计.................................................................... 16
4.1 关键器件介绍...................................................................................... 16
4.1.1 STC12C5A60S2简介 ................................................................. 16 4.1.2 步进电机介绍 ............................................................................ 18 4.1.3 光敏传感器及元件 .................................................................... 20 4.2 CPU模块设计 ..................................................................................... 21
4.2.1 CPU硬件模块结构框图 ............................................................ 21 4.2.2 CPU 模块电路原理图 ............................................................... 22
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华北科技学院
4.2.3 复位电路 .................................................................................... 23 4.2.4 晶振电路 .................................................................................... 23 4.2.5 发光二极管 ................................................................................ 24 4.3 光电传感模块...................................................................................... 24 4.4 实时时钟模块...................................................................................... 27 4.5 RS232通讯模块 .................................................................................. 28 4.6 EEPROM存储模块 ............................................................................ 29 4.7 系统电源设计...................................................................................... 30 4.8 步进电机驱动电路.............................................................................. 30 第5章 太阳能电池板跟踪系统软件设计........................................................ 31
5.1 Keil C51 软件介绍 ............................................................................. 31 5.2 软件总体设计及流程图...................................................................... 32
5.2.1 软件总体设计 ............................................................................ 32 5.2.2 软件流程图设计 ........................................................................ 33 5.3 软件关键模块设计.............................................................................. 34
5.3.1 串口通信程序设计 .................................................................... 34 5.3.2 EEPROM的读写程序核心代码 ................................................ 34 5.4 程序设计要点及注意事项.................................................................. 36 第6章 实验及结论............................................................................................ 40 第7章 总结及展望............................................................................................ 41
7.1 总结...................................................................................................... 41 7.2 展望...................................................................................................... 41 第8章 附录........................................................................................................ 42
8.1 控制板原理图...................................................................................... 42 8.2 部分数据结构...................................................................................... 42 8.3 部分软件代码...................................................................................... 46 参 考 文 献........................................................................................................ 53 致 谢.............................................................................................................. 54
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