Experimental Verification of High-Power Production Mechanism by Increasing Field Winding Current in Wound Field Flux Switching Motor for HEV Traction Drive

Abstract

As a type of non-permanent magnet motor, the Wound Field Flux Switching Motor (WFFSM) has attracted considerable research interest owing to its simple structure. Because both the field and the armature windings are placed in the stator, there is no need for bushes or a slip ring for field coil excitation. The rotor has neither a winding nor a permanent magnet, and therefore, it is suitable for high-speed and high-power-density motors used as HEV/EV drives.  This paper focuses on the high-power production mechanism of WFFSM by increasing the field winding current, which allows for the extraction of higher power from a given WFFSM within given inverter voltage and current constraints. In order to achieve higher power production, one of the main factors is reducing the armature reaction in terms of higher power factor control and applied voltage suppression. In this study, we focus on magnetic saturation by increasing the field current excitation, which leads to saturation of the armature reaction. Experimental studies using a 100-kW test WFFSM confirm that the high-power production mechanism based on increasing the field winding current contributes to the extraction of higher power from the tested WFFSM.