Study of winding method to reduce stray loss and stator core vibration of synchronous machine

The fractional slot windings are widely used in rotating machine in order to increase the flexibility of design and improve the voltage waveform. However, the MMF wave of fractional-slot windings are found to contain unique harmonic components, which are designated as even space flux harmonics, fractional flux harmonics, or both. They may cause stray loss and stator core vibration. This paper proposes new winding methods such as “novel interspersed windings” and “expanded group windings” to reduce these harmonics. The advantages of two proposed winding methods are verified by using numerical analysis and measurement test of winding model.