青岛理工大学毕业设计
摘 要
在绿色再生能源得到广泛应用的今天，太阳能因为其独特的优势而得到青睐。太阳能光伏发电受到世界各国的普遍关注，光伏并网发电也将成为太阳能利用的主要趋势，必将得到快速的发展。但因为光伏电池的转化效率较低且输出特性受外界环境因素影响大，使光伏电池实时输出最大功率成为关键。因此光伏最大功率跟踪也成为光伏发电系统的关键技术之一。
本文主要对光伏最大功率跟踪控制技术以及Boost（升压斩波电路）电路优化设计进行研究。首先，对光伏电池的电气进行测量，得到了光伏电池的输出特性；采用基于Boost的实现方案，分析光伏最大功率跟踪的工作原理，进行DSP单片机TMS320F2812实现扰动观察法的C语言编程。
最后进行样机组装并实验，实验证明，本设计能够完成对Boost电路的设计与优化，并能够较好的完成最大功率点跟踪。
关键词：光伏发电；最大功率跟踪；DSP；Boost电路；扰动观察
青岛理工大学毕业设计
ABSTRACT
Today the green renewable energy is widely used , solar is favored because of its unique advantages. Solar photovoltaic power is widely concerned around the world, photovoltaic solar power generation will also become the main trend of development and also be rapid. But because of low conversion efficiency of photovoltaic cells and the output characteristics are affected by the environmental factors, making the largest power of photovoltaic cells real-time output the key. Therefore, the maximum power tracking of solar photovoltaic power generation system has also become one of the key technologies.
In this paper, I will mainly research the maximum power tracking technology of the PV, design and improve the Boost circuit (Boost cut broken circuit). First, I measuring the electrical characteristics of photovoltaic cells , and get the output characteristics of photovoltaic cells; then based on Boost circuit of implementations, analysis the works of Photovoltaic maximum power tracking. Then, based an the DSP microcontroller TMS320F2812 , I use the method of perturbation and observation ,to do the programming based on C language.
At last, I assembled the sample machine and did experiments, those experiments showed that the paper can accomplish the design and optimization of Boost circuit. And the experiments also showed that the design can complete the maximum power point tracking.
Key words：PV；MPPT；DSP；Boost circuit；perturbation and observation
青岛理工大学毕业设计
目 录
摘 要................................................................................................................................ I ABSTRACT .......................................................................................................................... II 1 前言.................................................................................................................................. 11
1.1 选题背景................................................................................................................ 11
1.1.1 能源现状...................................................................................................... 11 1.1.2 太阳能光伏发电.......................................................................................... 11 1.2 本课题的研究意义和任务.................................................................................... 13 2单相光伏并网发电系统基本原理................................................................................... 13
2.1 单相光伏并网发电系统结构组成........................................................................ 14 2.2 主要部分工作原理................................................................................................ 15
2.2.1 DC-DC变换器 ............................................................................................. 15 2.2.2 DC-AC逆变器 ............................................................................................. 15
3 光伏电池的特性测量...................................................................................................... 17
3.1 光伏电池的等效电路模型.................................................................................... 17 4 硬件电路设计.................................................................................................................. 17
4.1 Boost电路工作原理 .............................................................................................. 20 4.2 Boost电路实现光伏最大功率跟踪的理论依据 .................................................. 21 4.3 Boost电路主要器件选择 ...................................................................................... 23
4.3.1 电感L .......................................................................................................... 23 4.3.2 电容C .......................................................................................................... 23 4.3.3 功率开关管V和二极管D ......................................................................... 24 4.4 控制电路................................................................................................................ 24 4.5 驱动电路................................................................................................................ 24 4.6 缓冲电路................................................................................................................ 25 4.7 检测采样电路........................................................................................................ 29
4.7.1 电压采样电路.............................................................................................. 30 4.7.2 电流采样电路.............................................................................................. 31 4.8 液晶显示................................................................................................................ 31 5 软件设计.......................................................................................................................... 32
5.1 光伏最大功率跟踪控制方法................................................................................ 32 5.2 光伏最大功率跟踪算法的实现............................................................................ 33 5.3 系统调试实验及分析............................................................................................ 36 结 论.............................................................................................................................. 40
青岛理工大学毕业设计
参 考 文 献........................................................................................................................ 41 致 谢.............................................................................................................................. 42 附录A 硬件电路总图 ........................................................................................................ 43 附录B 程序代码 ................................................................................................................ 44