A novel self excited hybrid brushless wound rotor synchronous machine with consequent poles

This manuscript presents a novel consequent pole hybrid brushless wound rotor synchronous machine (CPH-BLWRSM) topology. Compared to existing BLWRSM, the proposed topology mainly exploits the inherent subharmonic component (SHC) field excitation to attain brushless operation with limited usage of rare permanent magnet materials and assists in achieving improved torque attributes. The proposed CPH-BLWRSM topology is validated on a 12-slot, 8-pole machine with a 3-phase single-layer armature winding. The rotor of the proposed machine contains 4 poles of harmonic winding (HW), 8 poles of field winding, and permanent magnets on alternate poles. The armature winding on the stator is supplied by a single 3-phase inverter to generate stator MMF, which comprises two dominant components: (1) the fundamental component with supply frequency and (2) the subharmonic component (SHC) with half of the supply frequency. The fundamental component of the stator MMF produces the main stator field, while the SHC induces AC voltages in the HW. A rotating rectifier mounted between the HW and the field winding converts this AC to direct current (DC), and thus the field winding on the rotor receives DC from the rectifier without brushes. The JMAG-designer software is employed to perform 2-dimensional finite element analysis of 12-slot and 8-pole CPH-BLWRSM. The proposed machine exhibits high starting, maximum, and average torques as compared to existing BLWRSM with less input stator current magnitude, making it suitable for loads that require high starting torque.