Metal working power supply converter system and method

[0006]The present disclosure sets forth certain solutions that maybe implemented in welding and similar power supplies and that are designed to respond to such needs. In accordance with certain aspects of the present disclosure, a welding or cutting power supply system includes a converter circuit comprising first and second solid state switching circuits each having two power electronic switches for producing output power at a controllable level suitable for a welding or cutting operation, the first and second solid state switching circuits being electrically coupled in to provide combined output. An output inductance is coupled to outputs of both the first and second solid state switching circuits. Control circuitry is coupled to the first and second solid state switching circuits and configured to provide PWM control signals for controlling states of the power electronic switches of the switching circuits to maintain desired loading of the switching circuits independent of the level of the output power. For each cycle of the switching circuits the control circuitry is configured to apply PWM control signals to the first switching circuit based upon a desired duty cycle,

However, inductors in such systems can be quite large, implying additional cost and weight.

One problem in such systems exists insomuch as independently controlled inverter circuits can become unbalanced during operation.

The result can be a “walking” deviation in the duty cycles of the two inverte