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Summary: In this paper, an interior permanent magnet synchronous motor with a D‐type rotor configuration is presented. The performance of the proposed motor is compared with that of the widely used V‐type interior permanent magnet synchronous motor. For a fair comparison, all the motor parameters are identical. With the advent of different rotor topologies, multilayered and multisegmented permanent magnets are extensively used; however, an analytical modeling of D‐type interior permanent magnet synchronous motor has not yet been conducted. Furthermore, its analysis using the finite element method is considerably time‐consuming. To resolve this problem, an analytical method based on a magnetic equivalent circuit is proposed for the slotless D‐type interior permanent magnet synchronous motor. It is then compared with the finite element method at different pole arc–pole pitch ratios to demonstrate the effectiveness of the proposed method. Additionally, Schwarz‐Christoffel mapping is employed to maintain the slot shape and include the effect of adjacent slots by considering the slotting effect in the slotless air‐gap flux density. Finally, the presented motors are optimized based on the pole arc–pole pitch ratio to maximize the fundamental air‐gap flux density and minimize the total harmonic distortion. [ABSTRACT FROM AUTHOR]

In order to improve the air-gap flux density of the permanent magnet synchronous motor and reduce the cogging torque, a novel structure with asymmetric magnetic poles for automobile was proposed. Based on the characteristics of the parallel magnetic circuit, the magnetic flux path diagram is established. And the equivalent magnetic circuit model is established by the equivalent magnetic circuit method. The Taguchi method is used to be a multiobjective optimization algorithm. The total harmonic distortion of the air-gap flux density is the first optimization goal. The second and third optimization goals are the cogging torque and the average of output torque, respectively. And the torque ripple is a constraint condition. The optimized parameter combination is obtained by the Taguchi method. Finite element simulation analysis and prototype test are carried out for the optimized motor structure. The results show that the total harmonic distortion of air-gap flux density is reduced by 36.7% comparing with the initial structure. The cogging torque is reduced by 26.0%. And the average output torque is increased by 4.8%. [ABSTRACT FROM AUTHOR]

Summary: The structure of the rotor magnetic circuit has an obvious effect on the eddy current loss of the rotor of the high voltage line start permanent magnet synchronous motor. In this paper, a 10 kV to 1000 kW high voltage line start permanent magnet synchronous motor is taken as an example. The two‐dimensional electromagnetic field model of the motor with V‐shaped permanent magnet arrangement is established by using the finite element method. The no‐load back EMF and armature current of the motor are calculated, and the correctness of the model is verified. On this basis, this paper proposes a sector permanent magnet structure, compares the difference between the air gap flux density and the rotor eddy current loss of the two magnetic circuit structures, analyzes the advantages and disadvantages of the above magnetic circuit structure on the harmonic effect of the air gap flux density of the motor. The mechanism of the influence of different magnetic circuit structures on the eddy current loss of the rotor is revealed, which provides a reference for the design of a high voltage line start permanent magnet motor. [ABSTRACT FROM AUTHOR]