Synergistic controlled soft switch contravariant type double-wire pulse MIG arc welding power supply

Abstract

A cooperatively controlled soft switch inverter type dual-wire pulse MIG arc welding power supply is composed of two power supplies for master and slave arc welders, two digitalized coordinate control modules for said arc welding power supplies, and the CAN bus between said two control modules. Said power supply consists of main circuit, external average current closed-loop control circuit and internal peak current closed-loop control circuit. Said external average current closed-loop control circuit comprises current and voltage detecting module, pulse parameters giving up module, comparator, single-chip control system, phase-shift PWM module and HF driver module.

Description

technical field [0001] The invention relates to the technical field of mechatronics, in particular to high-frequency soft-switching inverter technology and twin-wire welding technology, and in particular to a cooperatively controlled soft-switching inverter twin-wire pulse MIG arc welding power supply. Background technique [0002] At present, in the field of twin-wire pulse welding, due to the high current and high power required by the process, the traditional twin-wire pulse welding power sources at home and abroad are mainly silicon rectifier and thyristor rectifier. The rectifier power supply is relatively reliable, technically It is also relatively mature, but the equipment is bulky, heavy, low energy consumption, low efficiency, and due to its structure, its dynamic and static characteristics are not ideal. The more advanced hard-switching inverter has small size, high efficiency, high technical content and high added value, but the working en...

AI Technical Summary

Problems solved by technology

At present, due to high-frequency parasitic oscillation, frequent and complex load changes, electromagnetic interference, and magnetic bias, hard-switching inverter arc welding power supplies have insufficient reliability, especially under high-power welding conditions.

[0004] (2) Large switching loss

Since the high-power inverter arc welding power supply mainly works in the hard switching mode, problems such as large turn-on and turn-off losses and diode reverse recovery are unavoidable, especially when high-frequency welding produces large switching losses.

[0005] (3) The control performance of the arc welding power supply

Due to the short control cycle of the inverter arc welding power supply, the fast dynamic response of the whole machine, and the complex load changes, it is difficult to precisely control it with an accurate mathematical model

[0006] (4) The problem of power factor

The hard-switching inverter arc welding power supply has deformed working waveforms and high-order harmonic interference, which reduces the power factor. The harmonics generated during the switching process will also be fed back to the power grid, causing pollution to the power grid. It can also cause severe electromagnetic interference

[0007] (5) Fever problem

At present, the soft-switching inverter arc welding power supply under research basically adopts the ordinary full-bridge phase-shift soft-switching topology. Although the implementation method is relatively simple, there are narrow soft-switching ranges, large commutation losses, and high output current at high input voltages. When it is small, it is difficult to realize zero-voltage turn-on and turn-off. The common full-bridge phase-shift soft-switching topology also has a prominent limitation, that is, the loss of duty cycle is large, and the output current and voltage of the power supply are very large at the pulse peak stage. It is likely to cause the failure of the power output in the pulse stage, and the irregular transfer of molten droplets, which will affect the welding quality

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