Research And Realization Of Soft Switch Technology On The System Of Digital Welding

The Papers introduce development status, trends of inverter technology atfirst,and then, based on comprehensive analysis of proposed soft-switchingtechnology to solve the hard-switching main power device switching stress, high loss,and low reliability, the project team studied the soft-switching system for arc weldinginverter topology, the work principle is analyzed, we selected phase shift controlfull-bridge zero-voltage zero-current pulse width modulation (PS-FB-ZVZCS-PWM)soft-switching circuit topology as the main circuit topologyControl circuit, the project located in the fully digital control. Digital signalprocessor (DSP) chip is the core of two-machine communication, real-time dataacquisition, PI regulation, PWM duty cycle control to achieve constant currentinverter output.In addition, in view of the DSP complex logical function is relatively weak, and toconsume a large amount of system resources, as the DSP of the auxiliary controldevices, the project team used ultra-low-power complex programmable logic device(CPLD) to complete welding signal, the logic of the protection signal processing,finished CPLD programming phase shift control of the overall structure andimplementation process.Finally, based on depth study of the theory,the project developed a digital controlCO2protection welding machine, tested key waveforms and the temperature rise inworking condition, The results showed that, full digital control CO2protectionwelding machine complete Complete zero-voltage switch of super-forearm, thezero-current Switch of Lagging arm, Effective avoid the process the main switchvoltage and current changes in the process of overlapping, Significantly lowerswitching losses and stress, Current stability，digital control CO2protection weldingmachine is a promising development of new welding power supply.