Origin and propagation of common mode currents occurring in a bridge rectifier

The aim of this paper is to investigate the generation of common mode currents in an AC/DC power converter, in particular a silicon controlled rectifier (SCR). In fact, this paper is intended to be a first step to understanding radiated electromagnetic noise emission from an SCR and to localizing its cause and place of origin. Particular attention has been paid to the conception and implementation of the experimental set-up. The main results conclude on the incidence of the operating point on the common mode current spectra, which is due to drive signal distortion owing to interaction between the drive and control unit and the power circuit. Moreover, important dependance of the spectra on power supply impedances has been observed