Design and Analysis of Brushless Wound Rotor Synchronous Machine for Adjustable Speed Operations

Abstract

This paper presents design and analysis of brushless wound-rotor synchronous machine (BL-WRSM) for adjustable speed applications. The brushless operation of wound-rotor synchronous machine is achieved by generating the spatial sub-harmonic component of stator magneto motive force (MMF). A specially designed stator winding, which comprises of two set of series connected windings with unequal number of winding turns is utilized for the generation of sub-harmonic MMF (SH-MMF). This additional SH-MMF induces voltage in the harmonic winding mounted on the rotor, which is then rectified and supplied to the field winding of the machine. A 2-D finite element analysis has been performed to analyze and verify the operation of the proposed BL-WRSM for adjustable speeds.