【作者】 顾公兵；

【导师】 田松亚；

【作者基本信息】 河海大学 ， 机械电子工程， 2004， 硕士

【摘要】 为了研制高效节能、性能优越的CO₂焊接电源，本文引入逆变技术针对电源的主电路、控制电路、驱动电路和送丝电路进行了研究和设计。在主电路设计中，选用输出功率大的全桥式拓扑结构，对以IGBT和中频变压器为核心的功率器件进行了详尽的参数计算，并分析、论述了IGBT的保护措施。控制电路基于SG3526的PWM控制技术，采用电压闭环负反馈产生平硬的电源外特性，采用电流闭环负反馈对短路过渡过程进行波形控制。提出采用电压、电流双环切换的办法实现波形控制的设想。在建立控制系统结构框图和数学模型基础上，借助MATLAB对系统进行仿真，设计了电子电抗器系统，用以控制电源动特性。文中还对采用微机系统参与焊接过程自动控制进行了软硬件设计。为了克服脉冲变压器式门极驱动电路制作、调试困难的缺点，设计了线路简单易调的光耦式驱动电路。在详细分析了IGBT上电流、电压波形和主电路输出波形的基础上，对实验结果进行了评估，解释了实验中出现的特殊现象。试验表明，主电路设计结构合理，器件工作可靠，输出波形良好。最后，设计了PWM调速电路配合印刷直流电机的送丝调速系统，试验表明，送丝速度误差在±5％以内，符合标准JB／T9533-1999。更多还原

【Abstract】 To build an efficient carbon dioxide (CO2) welding power resource with excellent property, the inversion technology is applied to design the main circuit, the control circuit and the driver circuit. The full bridge structure is used in main circuit in order to reinforce the power provided by the CO2 welder. The parameters of the power components including IGBT and transformer are carefully calculated, and the means of protection of IGBT (Insulted Gate Bipolar Transistor) is specially analyzed. Both the control of PWM (Pulse Width Modulation) generated by chip SG3526 and the closed-loop circuit with the negative feedback by voltage is applied to create strong static feature of the CO2 welder, which make its voltage stable when its load is changing. The block diagram and mathematical model of the system are built for the simulation by the software MATLAB, and the result of the simulation aids the designing of an electrical inductor, which can control the dynamic feature of the CO2 welder. The idea of controlling the current waveform by means of switching the current closed-loop or the voltage close-loop in different circuit state is brought out. The hardware and software of the microcomputer system are designed in order to control the welding process automatically. The driver circuit with pulse transformer has trouble to be made or adjusted, so the driver circuit used of photoelectric coupler is designed and made. By analyzing the current and voltage waveforms from the IGBT and the output of the CO2 welder in the tests, the conclusions have been drawn that the structure of the main circuit is valid and the components used in the main circuit are credible. In the end, the circuit of feeding wire of consistent velocity based on the technology of PWM is designed and tested in the experiment. The results of the experiment meet the standard of JB/T9533-1999.更多还原