Power supply design method for magnetic control plasma arc

Abstract

The invention discloses a novel power supply design method suitable for a magnetic control plasma combined arc, and relates to a method for controlling a zero jump interruption positive selection waveform based on a single chip microcomputer, so that a non-straight alternating current waveform which does not cross a zero point is obtained. The method is mainly used for solving the problem that an electric arc is unstable when an alternating current signal crosses a zero point and avoiding double arcs, a current waveform obtained through the method does not cross the zero point and is a non-straight waveform, so that the output current waveform can achieve a better arc stabilizing effect, and the control precision of a magnetic field to the electric arc is further improved; according to the technical scheme, the method is characterized in that a single-chip microcomputer control module and an A / D sampling module are included, and a single-chip microcomputer drive circuit, an SPWM double-bridge inverter circuit and a fundamental wave filter circuit in a zero-jump discontinuous sinusoidal waveform generation circuit are controlled through the control effect of a single-chip microcomputer to obtain needed fundamental waveforms through carrier wave separation; a zero jump discontinuous sine alternating current waveform not crossing a zero point is obtained; and then the alternating current passes through the upper and lower edge waveform shaping circuit and finally passes through the peak value grading power amplification circuit to be amplified by different multiples to obtain a plurality of zero-jump discontinuous sine alternating current waveforms with different initial peak values, so that the requirements of welding scenes with different welding currents are met.

Description

technical field [0001] The invention relates to a design method for a power supply of a magnetically controlled plasma arc, which belongs to the field of welding automation, and in particular uses combined plasma arc welding, penetration plasma arc welding, and penetrating plasma arc welding in operation modes such as micro-beam plasma arc welding. arc welding conditions. Background technique [0002] As we all know, conventional plasma arc welding and cutting mostly use transferred plasma arc, and when using micro-beam plasma welding and powder spray welding, most of them are combined plasma arc. At present, plasma welding at home and abroad generally adopts DC positive power supply to ensure The stability of the arc and the reduction of the burning of the tungsten electrode. However, when welding metal materials such as aluminum and magnesium, due to the requirements for cathode atomization, it is necessary to use DC reverse polarity or AC power supply, and DC reverse pol...

AI Technical Summary

Problems solved by technology

[0006] The present invention is mainly to solve the arc instability problem caused by the arc when the alternating current signal crosses the zero point. In order to further improve the stability of the combined plasma arc arc column and improve the welding quality, the alternating current provided by the traditional power supply passes through the zero point to the arc. The unfavorable influence of the stable arc of the column, which in turn affects the control accuracy of the magnetic field on the arc column, and affects the welding quality. Therefore, a single-chip microcomputer-based control SPWM double-bridge inverter circuit is provided, which produces no more than zero points such as image 3 The design method of the alternating current shown, the design method mainly includes the software part and the hardware part, the software part includes the single-chip microcomputer control module, the A / D sampling module, the capacitor charging and discharging self-adaptive system module, and the hardware part includes the zero-jump intermittent sine wave generation circuit, upper and lower edge waveform shaping circuit, peak grading power amplifier circuit

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