Use of fractional-conductor windings and semi-magnetic slot wedges in synchronous machines

Abstract

This paper discusses two methods of altering the harmonic content of the spatial air-gap flux density waveform in synchronous machines (generators and motors). First, fractional-conductor windings are analysed for adoption as a replacement for a conventional distributed winding arrangement, their advantages and disadvantages briefly discussed and an example design scenario presented. Second, analysis and discussion regarding the use of semi-magnetic slot wedges as a replacement for glass-fibre type wedges is presented to complement the choice of winding in synchronous machines. Both methods are shown to benefit machine performance under certain circumstances.

Keywords

• machine insulation
• AC machines
• permanent magnet machines
• air gaps
• synchronous machines
• machine windings
• conductors (electric)
• magnetic flux
• finite element analysis
• synchronous machines
• machine performance
• fractional-conductor windings
• semimagnetic slot wedges
• harmonic content
• spatial air-gap flux density waveform
• generators
• motors
• disadvantages briefly
• example design scenario
• discussion
• glass-fibre type wedges