| Fractional-slot concentrated windings PMSM is a special motor with particular stator structure. Because of its particular structure and properties, it's widely used in many occasions. Firstly, it has solved the problem of more poles but less slots. Secondly, by the equivalent distribution, the harmonic components of the electric motive force(EMF) have also been weakened in fractional slot concentrated windings PMSM, so it can improve the voltage waveform and increase the utilization rate of the windings. Finaly, Fractional-slot windings will produce more fractional harmonics, but they also weaken tooth slot harmonics and reduce the positioning torque of the PMSM.In traditional PMSM with short-range distribution windings, the harmonic of the air gap magnetic field is so little that it can be ignored. But in the PMSM with fractional-slot concentrated windings, the harmonic of the MMF has greater impact on the motors, and as the frequency increasing, it can also induct much more eddy-current in the rotor that can't be ignored. Eddy-current will cause a high temperature, causing partial demagnetization of the permanent magnet. Therefore, it is very necessary to research the eddy-current losses in the PMSM with fractional slot concentrated windings.In this paper, fractional slot concentrated winding theory and the principle about motor designing has been analysed firstly and the rule of the slot/pole number combinations has been summarized also. Then the winding factors and MMF harmonic components of the fractional slot windings have also been reasoned. Based on the relevant electromagnetic theory and finite element analysis theory, the no-loading and loading electromagnetic field distribution of the 8 pole 9 slot motor which is discussed in this paper has been concluded, according to the results, the induced voltage which effects the eddy current will be obtained in the post-processing. This results would be used in designing of the PMSM.
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