METHOD OF POWER SUPPLY FOR WELDING TRANSFORMER OF SINGLE-PHASE CONTACT AC AGGREGATES

摘要

FIELD: metallurgy. ^ SUBSTANCE: invention refers to welding, particularly to method of electric power supply for welding transformer in single-phase butt-welding AC aggregates. Method involves voltage generation with frequency of 3/4F for welding transformer with rated frequency F by two three-phase full-way controlled rectifiers connected in parallel opposition. Each voltage half-wave is generated by sequential commutation of two line voltages. Half-wave of one polarity begins with commutation of the same line voltage as in the end of previous half-way of another polarity. The method allows for power supply of contact flash welding aggregates with single-phase transformer from three-phase network. Obtained voltage pulse shape is favourable for high-quality welding joint as its peak factor KA is lower than for harmonic current welding. Selected line voltage connection sequence at the beginning and end of each half-wave enables reliable power supply and almost continuous welding current curve in most cases. ^ EFFECT: uniform load on three phases of welding aggregate power supply network. ^ 2 dwg