电气工程自动化毕业论文.doc

电气工程自动化毕业论文


基于模糊控制的弧焊电源的研究

摘  要
焊接是现代工业生产中不可或缺的加工方法，而弧焊电源是决定焊接质量的关键因素。逆变弧焊电源是近年来发展起来的一种小型、轻量、高效、节能的弧焊电源。模糊控制方以其适用范围广，控制精度高等特点已广泛应用于生产的各个领域，随着微机技术的发展，将其应用于弧焊电源已经成为可能。本课题以研究出性能优越、经济实用的逆变弧焊电源为目的，将最新的软开关逆变技术和先进的模糊控制方式结合起来应用于弧焊电源的设计之中。
本课题研究的主要内容是基于模糊控制的软开关式逆变弧焊电源的设计，在分析了全桥零电压逆变主电路的运行规律的基础上，详细介绍了主电路的设计方案，包括功率器件的选择、保护以及高频变压器的设计等;本课题采用集成化的微机控制，采用移相PWM控制方式实现逆变器的软开关，所采用的闭环反馈和模糊控制实现了电源的恒流输出，为提高控制系统的可靠性及抗干扰性能，本文采取了一系列有效的措施;按照弧焊电源所需实现的功能要求，本文开发了组成系统控制软件的主程序、中断服务程序及其它一些功能程序，并详细介绍了新型逆变弧焊电源的控制核心一一模糊控制器的设计过程。该逆变弧焊电源的输出具有很高的稳定性和良好的动态性能。

关键词: 逆变弧焊电源  全桥移相零电压  模糊控制

Abstract
Weld is an important method in process, welding power is the key factor which determines the quality of weld. Inverter welding power has developed rapidly because of its advantages such as high efficiency, energy saving, small bulk, light weight and multifunction etc. Fuzzy control has been applied in many fields, with the development of microcomputer technology, it becomes realizable to use fuzzy control in welding power The purpose of this subject is to develop high performance, economical and practical welding power. the newest soft-switch invert technology and advanced fuzzy control method combined to design welding power.
The main content of this subject is to design a full- bridge shift-phase inverter welding power with fuzzy controller, in the base of analyzing the running principle of full-bridge zero-voltage-switch inverter. The design of main circuit is introduced in detail.  This design includes the selection and protection of elements, the design method and calculation of high frequency transformer. In this subject, the low cost and integrated microcomputer are applied. The hardware circuit of this welding power is designed based on philips’s89C58 single chip computer. In order to realize the soft, switch of inverter， the shift-phase PWM control method is adopted. The welding current closed loop feedback control and fuzzy control systems are applied to gain the constant welding current external characteristics. Many anti-jamming measures are used to protect the reliability of control system. According to the functions soft the welding power， the software is developed which includes main program, interrupt service routines and some function subprograms The design of tow input and single output fuzzy controller is introduced in detail. The whole system is debugged and tested after completing sotf ware and hard ware design of the welding power The results make clear that this welding Power can export prospective constant current characteristic，and the inverter has excellent dynamic capabilities with fuzzy controller.
Key words: inverter welding power, phase shift full-bridge，ZVS, fuzzy control
目   录
摘  要 I
Abstract II
1  绪论 1
1.1  课题的背景和提出 1
1.2  弧焊电源的发展状况和研究现状 1
1.3  软开关 5
1.4  本文的研究内容、目的和意义 6
2  逆变弧焊电源原理及设计方案 7
2.1  逆变弧焊电源原理 7
2.2  设计方案确定 11
3  模糊控制器设计 15
3.1  模糊理论的提出及可行性 15
3.2  模糊控制基本原理 15
3.3  模糊控制器设计 16
4  主电路设计与实现 29
4.1  移相控制软开关全桥逆变器设计 29
4.2  高频变压器设计 33
4.3  输入整流器设计 36
4.4  输出整流器设计 37
5  控制系统软件设计 38
5.1  软件结构设计 38
5.2  控制系统主程序设计 39
5.3  外中断服务程序设计 44
5.4  数据采集控制 47
5.5  标度变换 47
6  逆变弧焊电源控制硬件系统设计 48
6.1  控制系统设计要求 48
6.2  控制系统的设计思路 49
6. 3  单片机核心电路设计 49
6.4 参数给定与操作键的控制 50
6.5  检测电路 52
6.6  A/D和D/A转换电路 53
6.8  驱动电路 57
6.9  显示电路 58
6.10  保护电路 60
7   结论 62
致   谢 63
参考文献 64