Modified phase shifted gate drive

摘要

A modified phase shift scheme that provides the minimum on-time and regulation benefits of the conventional phase shift method with the reduced circulating current benefits of the traditional PWM control. A welding machine comprises an inverter operatively connected to a controller, wherein the controller controls a welding process of the welding machine using modified phase shifted switching of the inverter.

主权项

1. A power source for an electric arc welder comprising:
inverter means having a primary circuit and a secondary circuit, where said primary circuit has four switches and is capable of alternately creating primary voltage pulses to induce secondary voltage pulses in said secondary circuit, and where said secondary circuit includes an output circuit capable of being connected to an output welding circuit; means for turning on a first switch and a second switch of said primary circuit to establish a fixed phase shift between a first resultant output pulse of said first switch and a second resultant output pulse of said second switch; means for turning off said first switch and said second switch subsequent to a minimum on-time of each of said first and second switches being achieved; means for turning on a third switch and a fourth switch of said primary circuit to establish said fixed phase shift between a third resultant output pulse of said third switch and a fourth resultant output pulse of said fourth switch; and means for turning off said third switch and said fourth switch subsequent to a minimum on-time of each of said third and fourth switches being achieved.