【作者】 王雪莲；

【导师】 陈克选；

【作者基本信息】 兰州理工大学 ， 材料加工工程， 2008， 硕士

【摘要】 数字化技术有着无比的优越性,它超越模拟技术的弊端大大推动了焊接电源的精确控制和柔性化的发展。数字化是焊接电源发展的必然趋势。本文首先介绍了“数字化”的概念,分析了数字化逆变弧焊电源的特征。结合当前数字化逆变弧焊电源在国内外的发展趋势,阐明了进行本课题研究的必要性。论文简要介绍了数字信号处理器DSP(Digital Signal Processor)的产生、应用领域及发展趋势等,接着详细阐述了其工作原理、结构特征及芯片的选型。重点介绍了所研制的基于DSP数字化IGBT逆变MMA/TIG焊接电源系统的组成部分和控制原理。分别就逆变电源的主电路、控制电路、保护电路、驱动电路和高频引弧装置做了详细分析,并从软硬件两方面进行了系统的阐述。电源主电路采用输出功率较大的IGBT全桥式逆变结构,由输入整流滤波电路、逆变电路、中频变压器、输出整流电路组成。文中详细介绍了主电路的设计要点及元器件的选型和参数计算。控制系统以16位数字信号处理器TMS320LF2407A为核心,采用了目前比较常用的脉宽调制方式PWM(Pulse Width Modulation)即控制IGBT的导通时间来实现焊机输出功率与输出特性的控制。由于TMS320LF2407A可以直接产生带死区的脉冲波形。驱动脉冲是利用TMS320LF2407A的比较单元输出一对带死区的PWM脉冲,经IGBT专用驱动模块M57959L进行功率放大后,触发IGBT。系统实时对输出电流进行采样,将采样结果送入到DSP进行A/D转换。论文还详细阐述了DSP片内的资源分配和外围电路的功能等。并针对焊接过程中可能出现的典型故障:过/欠压、过流、过热等,设计了相应的保护电路。针对非接触式高频引弧的高频干扰使DSP控制系统不能正常工作的问题,专门设计了相应的引弧控制电路来消除高频电磁波对DSP的干扰,提高了焊机的稳定性。文中详细介绍了DSP开发环境CCS2000的安装和设置以及开发工具5100USB的使用,并在此开发环境下采用汇编语言,以模块化方法设计了系统软件。文中还详细介绍了主程序、中断服务程序以及各种功能子程序的功能和结构。通过试验,对该电源的实现方案、组成部分进行了分析,得到了初步的试验结果,给出了在试验过程中记录的相关数据与波形;对试验过程中出现的问题进行研究分析,提出了解决方法。试验结果表明:该焊机主电路响应速度快,硬件电路简单可靠,系统软件高效、移植性好,抗干扰能力强,基本达到了最初设计的构想和要求。最后,针对本焊机的后续研究工作提出了进一步完善的建议,为数字化焊机今后的深入研究奠定了良好的基础。更多还原

【Abstract】 The digital technology has rather superiority.The development of accuracy control and flexible automation of inverter welding power source are promoted by it,which overcome drawback of analog technology.It is said that digital technology is developmental trend of inverter welding power source.This paper introduces the concept of digitalization firstly,then analyzes the characteristics of digital inverter welding power source.According to the research trend at homeland and overseas,it is very necessary to research.The give birth to,application field and development trend of DSP are introduced briefly and its work principle,structure characteristics and select are explained in detail.This paper emphasizes on the component parts and control principle of digitalized IGBT inverter MMA/TIG wave welding power source.Main circuit,control circuit,protection circuit,drive circuit and the equipment of high frequence arc starter are respectively analyzed.The software and hardware are also interpreted.Main circuit,which applies IGBT full-bridge inverter structure,is made up of input rectifier,filter,high-frequency transformer and output rectifier circuit.The key points and the parameters of design,select of parts of apparatus are discussed particularly.High performance 16-bit DSP TMS320LF2407A is adopted as control kernel.Using universal PWM method means to control output power and output characteristic through controlling IGBT switch on time.Because TMS320LF2407 can directly generate requisite pulse waveform with dead-band. The separate two pulses trigger IGBT after they are magnified by exclusive drive module M57959L.The system samples output current in real time and bring it to DSP for A/D conversion.This paper also expound the resource distribution and the function of outer circuits.Aim to typical problems in welding process:over voltage,lack voltage,over current and over heat, a corresponding protection circuit is designed.In order to overcome the high frequency interference of high arc starter to DSP control system,the corresponding arc starter control circuit is designed,which improves the stability of the power.The installation and setup of DSP develop environment CCS2000 and using of develop tool 5100USB are illuminated.Under the exploder environment,adopt assemble language,design system software by modularize methods.The frame and function of main program,interrupt service subroutine and devises function subroutine are explained.too.Transit experiment,analyse scheme and constitute of the power,gained the primary experiment results.Corresponding data and waveforms are recorded in the experiment,and problems occurred in experiment are investigated and lodge resolvents.The experiment results show that main circuit of the inverter power source has rapid response-speed,hardware has high reliability and simpleness,software has high effect,fine transplant and strong ability of anti-jamming.The inverter power source basicly achieved the compose and require of initially design.At last,some advices on future research for the welding power are given,and they will make a found ground for tomorrow’s research of digital welding power.更多还原