Research On Arc Welding Inverter Based On DSP

This paper briefly introduced arc welding inverter. Recently the AC/DC tache usually uses the uncontrolled or the phase controlled rectifier, and though the smooth DC voltage is available by the primary capacitor, it leads to the defaults of the low power factor and high harmonics of the whole plating power source. On the shortcoming of existing arc welding inverter, such as the big switching tension of main power transistor, the large wastage of machine, the low reliability and the pollution for the electric net, the paper adopts soft soft-switching circuit topology and PFC. To adapt the load demand, the ultrasonic power design power regulation function and adopt soft-switching Phase Shift PWM method to adjust the output power continuously. In order to suit the standard of limitations on harmonic pollution, circuit configuration of three-phase active power filtering converter including four switches is introduced. Theoretical analysis and formula derivation in arc welding inverter, soft-switching FB-ZVZCS-PWM converter circuit and four switch three-phase active power filtering converter are introduced.On the basis of three types phase-shifted control soft-switching FB-ZVZCS-PWM converter, the main circuit and control system of inverter are designed. The main circuit design are comprised of uncontrolled rectifier,power regulation function circuit and inverter circuit. The special DSP chip of TMS320LF2407A that produced by TI Company is used as main controller of the power to simply the system. It has completed functions: reading input of control panel; using A/D inverter and different arithmetic produces PWM signal in order to suit plating craftwork performance; dealing with troubles; system is online programmed and debagged using communication of DSP. Meantime the paper Design drivering circuit,resistive capacitive absorbing circuit and protective circuit including the over-voltage, over-current ,leaning magnetism and over-heat protection.On the basis of the theoretical analysis and circuit design, the result proved the design could achieve soft-switch and advance power factor, reduced the system loss and satisfied the request of harmonics. In addition, it can realize the power regulation continuously and achieve all kinds of protection function. The experiment proved the safety and reliability, excellent performance, high reliability and adaptability during the work. Consequently the system is worthwhile to recommend.