Design of protection circuit for arc welding power supply

The paper discusses the design of protection circuits responsible for the reliability of arc welding power supply. The protection circuits include three parts, and they are soft-start circuit for anti-surge, circuit for eliminating transformer DC bias magnetic field and circuit for transient over-voltage suppression, respectively. The detail calculations about component parameters of these circuits are given. The transformer and the power devices in this paper are regarded as ideal devices. Meanwhile, their losses are neglected. The method can provide certain guide for improving reliability of protection circuit.