Study on dynamic characteristics of inverter arc welding power supply based on double-loop control

Based on the small-signal model of the half-bridge circuit, the double close loops control system of the inverter arc welding power supply was designed under the average current control mode. For the control system´s voltage and current controllers, the loop gains, angular frequencies of zeros and poles were determined. The simulation model of the designed double close loops control system was established in Matlab/Simulink. The simulations of the steady-state and dynamic characteristics under the conditions of open load to short circuit, load to short circuit and short circuit to load were given out in large-signal. The parameters of the main circuit and control system were optimized according to simulation results. Finally, experiments were carried out and experimental waveforms were obtained. The experimental and simulation results were corresponded well and the rationality of the studying method was verified, a designing method to the inverter arc welding power supply was put forward.