A Novel Brushless Wound Rotor Synchronous Machine with Third Harmonic Field Excitation

Abstract

This manuscript discusses a novel harmonic current excitation technique for a wound rotor synchronous machine (WRSM) based on control of the time harmonic magneto-motive force (MMF) for brushless operation. Two inverters are used to feed the armature winding in such a way, that, at a time one inverter supplies the current to armature winding. The two inverters are 180° phase shifted. The inverter assignment multiplexing (TDM) is based on time division technique to generate continues armature currents containing reasonable third harmonic component beside fundamental component. This third harmonic current component generates pulsating MMF and is induced in the rotor harmonic winding; the induced current is rectified and applied to rotor field winding to generate rotor field. The rotor field interacts with armature fundamental current component for torque generation. Finite element analysis is performed to verify the idea.