基于DSP和FPGA实现三相整流焊机数字控制和触发

Research on digital control of three-phase rectifier welding based on DSP and FPGA

针对大功率直流电焊机的工艺结构和工作特点,分别对电焊机输出电压和电流进行取样,通过DSP进行PI运算,并由FPGA实现SCR的实时触发。其实现方法是采用DSP处理器控制整个电焊机的性能和功能并与FPGA通信,FPGA适时控制晶闸管SCR的触发导通,并确保6个SCR按顺序导通,同时通过对负载电压和电流的采样值确定SCR的导通角,从而控制输出电压和电流的大小,通过实验表明该数字控制使三相桥式整流出来的直流电压纹波小,谐波含量成分低、系统运行稳定可靠、设备体积小、成本低、便于携带并能精确控制电焊机的电压和电流。

In this paper, aims operating the feature of and configuration in the high-power electric-welding machine, samplies output current and voltage of load and PI control to current and vohage.h is use DSP to control performance and function and interface FPGA in the welding.FPGA control six SCR＇s trigger timely and trigger angle to control wilding＇s current and voltage.Finally,the experiments prove that the three-phase rectifier can have good precision.What＇s more ,this method decreases greatly the harmonic wave and ripples of power supply systems.The control method can not only realize the functions of the whole system,but also run more precisely and steadily.