In this paper, the EMI noise characteristics on a three-phase SJ-MOSFET inverter composed of a pulse transformer type recovery-assist circuit are experimentally verified. First, the configuration and operation principle of the proposed pulse transformer recovery-assist circuit are described and an example of implementation to a 3.7 kW three-phase SJ-MOSFET inverter is presented. Next, the conducted noise and the radiated noise in case of driving a three-phase 3.7 kW induction motor with or without a recovery-assist circuit are verified. The EMI noise characteristics are measured based on CISPR11 at EMC site. Finally, the difference between EMI noise with and without a recovery-assist circuit is verified from the viewpoint of"Modeling of EMI noise source p"roposed by the author.
