Design and implementation of synchronous rectification for an arc-welding machine

In Arc-Welding Machines (AWM), the power-to-weight ration is an important project parameter. This paper brings a proposition to use synchronous rectification to lower rectification stage's power losses on semiconductors, increasing total efficiency. A commercial product was studied, tested and characterized and a synchronous rectifier was then designed to replace the passive diode rectifier. A model of the machine was created and verified by comparison with measured behaviour and then used to simulate the synchronous rectifier application. Simulation results showed a promising reduction in power losses, which could be used in reducing the machine's size or increasing its power rating. In both cases, an improvement of power-to-weight ratio is verified. Ultimately, bench tests and welding tests were made to establish a comparison point between the machine with passive rectifier and the machine with synchronous rectifier.