Theoretical and experimental evaluation of the power losses in CM active EMI filters

This paper is focused on the analysis of the power losses in a common mode (CM) active EMI filter for induction motor drives. The different contributions to the total power losses associated to the active filter are theoretically defined and experimentally evaluated with reference to a given PWM induction motor drive. The single contributions to the total power losses due to each part of the active filter are accounted for and their dependence on the motor drive size is addressed. Furthermore the relation between each losses contribution and the reduction of the drive efficiency is evaluated.