Novel interspersed windings to reduce space flux harmonics caused by fractional-slot of synchronous machine

Fractional-slot windings is widely used in synchronous machine due to give us more flexibility on selection of the number of slot at design stage. It is also known that fractional-slot windings produces additional harmonics compare to integral-slot windings. These harmonics may cause increasing of stray losses and stator core vibration This paper describes the result of space flux harmonics caused by fractional-slot windings and propose novel interspersed windings that reduces the even order and/or fractional number space flux harmonic components. The advantage of proposed winding was confirmed by using numerical analysis and experiment using model winding machine.