Implementation of Forward Converter with Active Clamp for Welding Machines

Among the converters used in welding machines, two-switch forward converter has an important place in low and medium power applications for cost priority applications. However, one of the most important disadvantage of this converter is limited duty cycle, which is less than 50%. Therefore, the capacitors used for shaping the main line voltage occupy an important place on the circuit. Another disadvantage of the converter is that the transformer uses the B-H curve unidirectional way. This causes the transformer to be selected larger when compared to other converters for the same power value. In this study, it has been suggested use forward converter with active clamp to which provides using the B-H curve bidirectional way with clamp capacitor, extending duty cycle more than %50 and increasing power density solve these disadvantages of two switch forward converter for welding machines. For this purpose, a converter with 230V input; 25V/150A and 3750W output will be designed and simulated to show that the converter solves the mentioned disadvantages.