Conducted EMI analysis of hard and soft switching arc welding power supplies

The switching actions of power semiconductors cause unwanted electromagnetic emissions of switched-mode power supplies. The dv/dt- and di/dt-values of the voltage and current slopes at the semiconductors as the origin of disturbances can be reduced using resonant or soft-switching techniques which may represent an extra effort concerning the design of the power supply. The consideration and optimization of the propagation paths give further possibilities to reduce conducted electromagnetic emissions. In this paper, the effectiveness of different electromagnetic interference (EMI) reduction techniques will be experimentally evaluated.