Novel Self-Excited Brush-Less Wound Field Vernier Machine Topology

Abstract

To realize the brush-less operation for wound field vernier machines (WFVMs), a novel selfexcited topology is proposed in this paper which involves a four-pole main armature winding and a twopole excitation winding connected in series using an uncontrolled rectifier. Upon supplying current from a single current-controlled voltage source inverter (VSI), this procedure results in four-pole and two-pole magnetomotive force (MMF) components in the airgap. The four-pole MMF produces the main stator field while the two-pole MMF component develops a sub-harmonic field in the airgap. The rotor is altered to house a forty-four-pole rotor field and two-pole harmonic windings. The two-pole harmonic field is employed to induce a current in the harmonic winding, which is rectified by means of a full-bridge diode rectifier to energize the rotor field winding and realize brush-less operation for WFVM. Two-dimensional finite element analysis (2-D FEA) is implemented in JMAG-Designer to confirm the operation of the proposed WFVM topology and attain the electromagnetic performance for a four-pole, twenty-four-slot outer-rotor vernier machine.INDEX TERMS Wound field vernier machine; harmonic field excitation; self-excited machines; wound rotor.

Torque Ripple Reduction in Brushless Wound Rotor Vernier Machine Using Third-Harmonic Multi-Layer Winding

“…Here, 2D-FEA was utilized for the performance analysis of the proposed WRVM under no load and load conditions. A performance comparative analysis of the proposed and recently developed brushless WRVM topology [14] was carried out in JMAG-Designer, which confirmed the improved torque characteristics and low torque ripple for the proposed brushless WRVM topology.…”

“…This model also achieved improved torque performance as compared to one proposed in [12]. Similar work was conducted by introducing a four-pole main armature and a two-pole excitation winding connected in series through an uncontrolled rectifier for subharmonic generation [14]. The topology was simple due to the single-phase winding, and the excitation was improved, which led to higher torque as compared to the other vernier machines.…”