晶闸管弧焊整流数字控制

Research on digital control for arc welding rectifier of SCR

针对大功率弧焊整流焊机的工作环境及特点,详细分析弧焊整流电源的拓扑电路和数字控制。在焊接过程中,根据焊接需要,焊接电流应实时变化,当通过改变SCR触发角不能满足焊接功率时,可通过改变三相变压器输出的电压值来自适应焊接电流的大小,因此采用多输出变压器来满足宽范围的焊接电流;在数字控制中采用DSP和FPGA共同实现焊接电压、电流和温度采样以及用FPGA对SCR可靠稳定的触发。采用DSP芯片处理器控制整个电焊机的性能和功能以及开关量信号的采样,由FPGA运算SCR触发导通角的大小,并发出触发信号使SCR可靠稳定的导通和关断。通过理论分析,验证了该控制系统拓扑电路的正确性以及控制方法的可行性,从而保证系统能稳定和可靠的运行。

With the working environment and characteristics of high-power arc welding rectifier,the paper detailed analysis of tile topology of the arc welding rectifier power supply circuit analysis and digital control. In the welding process, according to the welding needs the size of the welding current value changes in real time ,by changing the trigger angle of the SCR can not meet the welding electric power, can be derived from the size of the adaptation of the welding current by changing the voltage value of the three-phase transformer output,in this paper, a multi-output transformers to meet a wide range of welding current value ; digital control using DSP and FPGA welded together to achieve the voltage,current and temperature sampling and FPGA reliable and stable trigger the SCR. Use a DSP chip processor controls the entire welder performance and function,as well as the switch signal sampling operation by the FPGA SCR to trigger conduction angle size,and a trigger signal to the SCR reliable and stable turn-on and turn-off. Through theoretical analysis and experimental verification of the correctness and the feasibility of the control method of the control system topology circuit,in order to ensure a stable and reliable system operation.