Stator teeth eddy-current loss analysis of interior permanent magnet machine during flux weakening

Due to the rotor saliency of interior permanent magnet (IPM) machine, large harmonic eddy-current loss in the stator iron loss can be caused under flux-weakening operation, conspicuous impairing the output performance of the IPM machine. In this paper, a new stator teeth eddy-current loss analysis approach is proposed. Based on the analysis approach, the teeth eddy-current loss is divided to two parts, one part is caused by the synchronous air-gap flux density rotating synchronously with rotor, while the other part is induced by the asynchronous air-gap flux density. Two indexes are employed corresponding to the above mentioned eddy-current losses in teeth. The impact of magnet pole-arc coefficient and slot number per pair per pole on the indexes is investigated. The finite element analysis method is used to validate the proposed formulation.