ABSTRACT The dual-armature (DA) winding configuration, which integrates armature windings on both the stator and rotor, provides an effective means to enhance the torque capability of conventional flux-switching electrically excited (FSEE) machines. However, the underlying electromagnetic mechanism responsible for this enhancement remains largely unexplored. To address this gap, this paper presents a comprehensive investigation of the airgap magnetic field in a 24-stator-slot/10-rotor-tooth DA-FSEE machine, aiming to identify the dominant airgap field harmonics and the corresponding torque components. The analysis reveals that the 4 th , 6 th , and 16 th airgap harmonics are dominant, with torque critically dependent on the 6 th harmonic pair arising from the DC-rotor interaction. The torque enhancement mechanism is further elucidated by the synergistic utilization and coordination of multiple torque sources. Beyond the I d =0 control, further torque improvement can be achieved through adjustment of the stator and rotor current angles ( φ s and φ r ), which leverages the torque contribution from the dual-armature interaction. Specifically, the torque of the target DA-FSEE machine remains relatively large and stable near φ s =0°, but an appropriate negative φ r is critical for large torque output, with the optimum occurring at φ r =-40°.
Wen et al. (Fri,) studied this question.