基于单片机的DC-DC变换器的研究(毕业论文).doc

本科毕业论文

设计题目:基于单片机控制的DC-DC变换器研究
学生姓名:
学号:
专业:电气工程及其自动化
指导教师:
学院:电气工程学院
基于单片机控制的DC-DC变换器设计
专业:电气工程及其自动化姓名: 指导老师:
摘要本毕业设计通过网上和图书馆获取资料,在查询了DC-DC变换器的特点和发展状况后,了解了它在实际生产应用方面的不足。第一,能量传输由高频变压器来完成是DC-DC变换器会有的一些不足,开关电源一般工作在几百KHz以上,因此会产生电磁干扰,故可能会影响其自身或其它系统的正常工作;除此以外,开关电源也存在输出电压纹波较大的问题。设计一种基于单片机控制的DC-DC变换器可以弥补它在应用方面的不足。于系统的实现上,单片机因具有计算机的基本组成部分与功能,又具备体积小,电路精简、故障概率低、可靠性高及成本低等优点,因而被应用于DC-DC变换器PID控制系统的实现。本系统通过输出PWM信号由单片机控制三极管的通断,达到控制电压的输出,模数转换器则转换输出信号并反馈给单片机分析和处理,使系统变为闭环。本设计分模块详细地阐述了升降压型DC-DC开关电源以及其控制、反馈电路的设计,分为单片机控制输出电压、DC-DC变换、单片机闭环参和控制DC-DC的输出,三个阶段说明此变换器的实现原理。
本设计应用软硬件相结合组成的实际控制系统。设计过程主要分成以下几个部分:算法确定,程序编写,结构模型建立,电路设计,总结。
关键词开关电源,单片机,PWM,闭环控制,ADC
Abstract
The graduation project by querying the data, the development and application of DC-DC converter, know the lack of production applications. DC-DC converter has its own ings, one of which is the application of high-frequency transformer for energy transmission device. Switching power supplies typically operate at more than a few hundred KHz, produce ic interference, it may affect their own or other system to work properly; addition, the switching power supply output voltage ripple larger issues. Designed for the deficiencies in the application of a new microcontroller-based control DC-DC converter. In the implementation of the system, the microcontroller ponents and functions of puter, but also with small, streamlined circuit, low failure probability, high reliability and low cost, which is applied to the DC-DC converter PID control system is achieved. The system adopted by the microcontroller output PWM signal to control switching transistor off, thus achieving the purpose of controlling the output voltage, the ADC is to convert the output signal and the feedback to the microcontroller analysis and processing, to form a closed-loop system. The sub-module of the design detailed description of the design of the buck-boost DC-DC switching power supply and control, the feedback circuit, divided into single-chip