A Novel Fractional Slot Non-Overlapping Winding Hybrid Excited Machine With Consequent-Pole PM Rotor

Abstract

A novel fractional slot non-overlapping winding (FSNW) hybrid excited (HE) machine with consequent-pole permanent magnet (PM) rotor is proposed in this article. The abundant harmonics in the stator magnetomotive force (MMF) of FSNW, which are harmful and tend to cause parasitic effects in conventional PM machines, are utilized to regulate the magnetic field and produce torque through field modulation. The DC excitation current can be injected by open-winding drive circuit and a biased current excited HE machine without field winding can be achieved, which solves the spatial confliction of field and armature windings. The electromagnetic performances of the proposed HE machine are evaluated with finite element method (FEM). It is revealed that the DC excitation can effectively regulate the magnetic field, and consequently, the back-EMF as well as electromagnetic torque. Finally, a prototype is fabricated and tested to validate the theoretical analyses and FE calculations.