CO_2气体保护焊逆变电源闭环控制系统

建立了CO2气体保护焊焊接负载数学模型及相关电源—负载系统仿真模型;采用燃弧末期恒压控制、其余阶段表面张力过渡(surface tension transition,STT)电流波形控制的焊接逆变电源闭环控制结构,设计了焊接电流和电弧电压的模糊神经元PI控制器,构建了CO2焊接逆变电源控制系统仿真平台.结果表明,所设计的闭环控制结构和控制算法能使焊接电流更接近理想的STT电流波形,可改善焊缝成形质量、实现无飞溅过渡;燃弧末期电弧电压恒定,可使电弧有更好的自调节特性.

Research on closed-loop control system of CO2 shielded arc welding inverter power source

Mathematical model of the burning arc and short circuit stage for CO₂ shielded arc welding and related power source-load simulation model were set up. The closed-loop control structure was adopted in the study, in which the current and arc voltage were uninterrupted switching. Namely, the constant voltage control was applied at the end of burning arc stage, and the current control of given STT (surface tension transition) current waveform was applied at the other stage. The fuzzy neuron PI controller of current and arc voltage was designed. The simulation platform for CO₂ shielded arc welding inverter power source control system was established. Simulation results show that the closed-loop control structure and control algorithm proposed in the study can make the welding current more close to the ideal STT current waveform. It can improve the appearance of welding and realize transition without splash. The invariable arc voltage at the end of burning arc can make the arc self-regulation characteristics better.