Performance Improvements in an Arc Welding Power Supply Based on Resonant Inverters

This paper describes improvements developed in an arc welding power supply based on resonant inverters. A new stand-by operation sequence based on sliding phase is proposed in order to reduce the discharge capacitor size. This stand-by solution also relieves the voltage specification of the resonant inductor. The interleaving operation of paralleled stages and the output connection wires are used to minimize the output capacitor current ripple and so extend the power supply´s lifetime. Moreover, synchronous rectification is proposed in order to increase the efficiency and reduce the operation temperature of the output power stage. Finally, sequences are described for establishing and extinguishing arcs. TIG welding is selected for testing operations.