Magnetic forces and vibration in permanent magnet machines with non-overlapping concentrated windings: A review

Permanent magnet machines with non-overlapping concentrated windings have been gaining importance in the last few years. Significant advantages such as short end-windings, high efficiency and low cogging torque make them an attractive option in several applications. However, due to a large harmonic content in the MMF and also particular pole and slot combinations, the vibration level of these machines is considerably higher than the machines with distributed windings. This paper discusses this problem and reviews the works presented in the literature concerning magnetic forces and vibration in PM machines with concentrated windings.