Novel Self-Excited Brushless Topology for Wound Field Vernier Machine

Abstract

This paper proposes a novel self-excited topology for the brushless operation of wound field vernier machines (WFVMs). The proposed topology involves a new armature winding configuration that develops fundamental and sub-harmonic magnetomotive force (MMF) components in air gap once the armature winding of the machine is supplied current from the inverter. The rotor of the machine is equipped with a harmonic winding which is used to induce current from the sub-harmonic MMF component of the air gap flux. The induced power is rectified to energize the main rotor field winding to the main rotor field. The electromagnetic interaction of stator and rotor fields along with the existence of the gearing effect develop torque. 2-D finite element analysis (FEA) was carried out to validate the theory for an outer rotor wound field vernier machine model.