Application of Flat Rectangular Wire Concentrated Winding for AC loss Reduction in Electrical Machines

The increase of power and speed requirement on the electric machine has imposed a concern on the high losses at high speed, especially on the winding AC losses. To deal with this, a flat rectangular wire is proposed to minimize the winding AC loss due to the skin effect and proximity effect. The impact of conventional circular wire strands on AC loss are analyzed and compared with the proposed flat rectangular wire configuration. Both open slot and semi-closed slot stator structures are evaluated. Finally, a 24 slots, 16 poles fractional slot concentrated winding (FSCW) permanent magnet (PM) synchronous machine prototype using flat rectangular wire and open slot stator is built to demonstrate the manufacturing of flat rectangular wire.