【作者】 缪正平；

【导师】 黄石生；

【作者基本信息】 华南理工大学 ， 材料加工工程， 2010， 硕士

【摘要】 双丝脉冲MAG高速焊技术集高效优质和自动化于一体,愈来愈受到重视,已成为国内外焊接领域的研究热点,但是国内的相关研究起步相对较晚,并且还不能批量生产这种双丝焊装备。本论文在广东省科技计划(No.2007A010300005)项目的资助下,结合电力电子技术和数字化控制技术,提出了基于DSP的双丝脉冲MAG高速弧焊电源的数字化系统,并对其特性和应用进行了研究。论文首先分析双丝脉冲MAG高速焊相关特征,完善了协同控制的主从机双丝脉冲MAG焊总体方案。分析了主从机逆变式弧焊电源主电路拓扑结构,根据输出功率要求,弧焊电源主电路采用并联式全桥逆变主电路拓扑结构;针对双丝脉冲MAG焊控制系统的要求,分析了外特性的选择和多相位协同控制方案。设计了以DSP为核心的硬件和软件控制系统,实现了双丝高速焊的多相位数字化协同控制。通过对双丝高速焊试验场所干扰源的分析,进行了硬件和软件的抗干扰设计。针对双丝高速焊主从机电源峰值阶段恒流+基值阶段恒流外特性方式的电弧自调节能力差,电弧电压波动大的缺点,本论文采用电压阈值方法和PI控制基值时间方法来控制弧长,实现了双丝高速焊过程中弧长的稳定控制。为了实现双丝脉冲MAG焊电源多参数的精确给定、记忆与显示问题,本课题设计了基于DSP+LCD结构的数字化人机交互系统。本论文进行了DSP与LCD、触摸屏、EEPROM等接口的硬件设计,并在此基础上进行了相应的软件设计,通过RS232总线与焊接过程控制系统进行通信,实现了弧焊电源人机界面的数字化。应用所研制的双丝脉冲MAG高速焊多相位数字化协同控制电源装备进行了大量的双丝高速焊工艺试验。试验结果表明,所研制的双丝脉冲MAG高速焊电源控制系统满足设计要求,实现了双丝焊同步、交替和随机三种相位输出焊接过程,并在合适的脉冲焊参数匹配条件下,焊接过程稳定、焊接速度快、焊缝成形好。更多还原

【Abstract】 Twin-wire pulsed MAG high speed welding technology possesses the advantages of high efficiency, quality and automation, and is paid much more attention today, it has become the research focus in the welding field. However, our country’s research on it is later and can’t produce this kind of twin-wire welding equipment in batch production. Under the project of Guangdong Industrial Technology research (No.2007A010300005), based on power electronics and digital control, this paper presents a research on the multi-phase digital synchronic control systems base on DSP for twin-wire pulsed MAG high speed welding power supply and their character and application.Firstly, the features of twin-wire pulsed MAG high speed welding are analyzed. The control system based on I/O communication of master and slave power supply is proposed. The main-circuit topology of the master and slave inverter is analyzed, and with the request of output power, the parallel full bridge inverter topology. To meet the requirements of control system for twin-wire pulsed MAG high speed welding power supply, the selection of external characteristic and the multi-phase digital synchronic control system are put forward.Secondly, the hardware and software of the multi-phase digital synchronic control system based on DSP are designed, it has been proved that the hardware and software are feasible and practical. Disturbance resistance of the hardware and software is also designed via investigating disturbance source of welding location.Thirdly, because the power supply choose the constant current external characteristic, it causes the disadvantages of weak arc voltage self-adjusting ability in master and slave power supply. In order to overcome the disadvantages and achieve the control of arc length, the voltage threshold method and PI control method of pulse base’s time are adopted.Fourth, the digital system controller based on DSP and LCD of human machine interface (HMI) is designed in order that the Pulse MAG welding power supply’s parameters can be given accurately, stored and displayed.This paper has designed the hardware about DSP with LCD, touch screen, EEPROM and other interface’s circuit, and the corresponding software has also been designed. The human machine interface communicates with the welding process control system through the RS232 bus. It has achieved a digital man-machine interface.Finally, the technologic experiment of twin-wire welding was done with the equipment of twin-wire pulsed MAG high speed welding power supply and its multi-phase digital synchronic control system. The results of the experiment demonstrate that the developed twin-wire power supply’s control system meet the design requirements, the twin-wire welding process was realized in synchronization, alternation and random three type phases output mode, and the merits of twin-wire pulsed MAG high speed welding are stable welding process, high speed, and high quality welding seam in the appropriate matching of the welding parameters.更多还原