摘 要：为了解决光伏电池阵列失配情况下的效率降低问题，本设计根据光伏电池的工作原理，分析了光伏电池的等效电路及其数学模型，并概述了光伏电池输出特性。然后介绍了4种MPPT控制策略方法，包括选择了有简洁系统结构的变步长扰动观察法来实现最大功率跟踪点的整个过程。研究了DC/DC转换电路，介绍了升压、降压斩波电路，选择了BUCK电路来实现转换。总体讲，设计了光伏发电系统中MPPT系统，采用AT89S52实现对DC-DC转换电路的控制，采样电路的模拟信号通过ADC0809转换为单片机需要的数字信号，以TL494模块作为驱动电路等实现了最大功率点跟踪。55454

毕业论文关键词：光伏发电系统,最大功率点跟踪,变步长扰动观察法

Abstract: In order to solve the efficiency of the photovoltaic battery which array mismatch casing degradation, this design according to the working principle of the photovoltaic cells photovoltaic battery equivalent circuit and mathematical model were analyzed, and summarizes the photovoltaic battery output characteristic. Then this paper introduces the method of four kinds of MPPT control strategy, which chose the disturbance observation method of system with simple structure to realize the whole process of maximum power tracking point. DC/DC conversion circuit is studied, and this paper introduces the step-up and step-down chopper circuit, choosing the BUCK circuit to realize the transformation. Overall speaking, photovoltaic power generation system is designed in the MPPT system, adopting the AT89S52 control system for the DC to DC conversion circuit, sampling circuit of the analog signal through ADC0809 conversion for single chip microcomputer to digital signal, TL494 module as the drive circuit and so on to achieve the maximum power point tracking.

Keywords:Photovoltaic system, maximum power point tracking, variable step perturbation and observation method

目 录

1  绪论 4

1.1 光伏发电的背景与意义 4

1.2 国内研究现状和趋势 5

1.3 立题目的及研究内容 5

2 光伏电池原理及特性 5

2.1光伏电池概述： 5

2.2光伏电池等效模型 6

2.3光伏电池输出特性 7

3 MPPT控制策略研究及系统设计方案 7

3.1 电压回授法 8

3.2 功率回授法 8

3.3 扰动观察法 8

3.4 增量电导法 10

3.5 改进型变步长扰动观察法 11

3.6设计方案 12

4 DC-DC转换电路 13

4.1 DC-DC转换电路介绍 13

4.2 Buck及BOOST电路原理图 14

4.3 DC-DC转换模式选择 16

4.4系统中蓄电池的选用 19

5 控制电路设计 19

5.1 控制芯片选择及应用 19

5.2采样电路的设计 21

5.3 信号转换电路的设计 22

5.4 PWM输出及MOSFET驱动电路 24

5.5辅助电源设计 26