Wye-delta winding configuration for brushless operation of a wound field synchronous machine

Abstract

This manuscript proposes a wye-delta winding configuration for brushless operation of a wound field synchronous machine (BL-WFSM). In existing third harmonically excited BL-WFSM topologies, the additional third harmonic component of the stator magnetomotive force (MMF) was produced by an extra thyristor drive circuit or by utilizing an additional inverter. In the proposed single inverter topology, the stator winding is divided into two coil sets: the wye coil and delta coil. Triplen harmonic currents are produced owing to the delta coils set and start to circulate in the delta coils. This triplen harmonic circulating currents produce a triplen harmonic pulsating MMF in the airgap. The additional triplen harmonic pulsating MMF induces voltage in the rotor harmonic winding. This induced voltage in the harmonic winding is used to excite the rotor field. A 2D finite element analysis is performed, and the simulation results confirmed the operation principle of the proposed brushless topology.