数字脉冲MIG弧焊电源的设计

Design of digital control pulsed MIG arc welding power source

针对模拟控制和单片机控制的脉冲MIG弧焊电源控制系统灵活性差、控制精度低和可靠性差等缺点,设计了基于DSC和MCU的数字控制系统,并介绍了系统的硬件电路设计和软件流程.由DSC采用变参数PI控制方法实现电弧电压和焊接电流的闭环控制,PI控制的参数由MCU中的专家系统确定.在MCU上,对嵌入式操作系统μC/OS-Ⅱ的内核进行了裁减和移植,并设计了包括专家系统在内的多个任务.结果表明,基于DSC和MCU的脉冲MIG焊接电源控制系统动态响应快、可靠性高、弧长控制稳定.

Aiming at some of deficiencies in the control system with analogous control technology and single-chip control technology, such as poor flexibility, control precision and reliability, a control system based on a digital signal controller (DSC) and micro control unit (MCU) for pulsed metal inert gas (MIG) arc welding power source is designed, and the hardware circuit and software flow chart of the system are presented. In the system, DSC with the variable parameter PI control algorithm controls the arc voltage and welding current, and the parameters of PI controller are determined by an expert system in MCU. The real-time kernel of the μC/OS-Ⅱis reduced and ported in MCU, and multiple tasks including an expert system are designed. The experimental results show that the control system based on DSC and MCU for pulsed MIG arc welding power source has the advantages of quicker response, better reliability and more stable arc length.