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Detent force is an inherent problem of permanent magnet linear synchronous machines (PMLSMs). In this paper, a mesh-level design methodology is proposed to minimize the detent force on PMLSMs. The novelty concerns introducing the inverse-based design to shape the mover ends on PMLSMs, allowing for automatically exploring the ideal mover ends configuration without any pre-given template. To this end, the ON/OFF method is used to express the topology of mover ends, metaheuristics algorithms are used to steer the topological evolution. To clarify the proposed method, two typical PMLSMs are adopted as numerical examples. The resulting mover ends produced by the genetic algorithm and immune algorithm are presented, and the convergence of the two algorithms is discussed. The comprehensive numerical results show that the proposed method is universal and practical as the detent force of the two typical PMLSMs can be suppressed to a low level.

The virtual equivalent line method for the axial-flux permanent magnet eddy current coupler is proposed in this paper to solve the problem of the difference in the length of the magnetic flux path between the inner radius and outer radius of the axial section of the radial centerline of the magnetic pole. Different from the average radius equivalent method, the virtual equivalent line method adopts the function of variable pole radius instead of the fixed average radius, which establishes a uniform analytical expression of the air gap flux density and can accurately calculate the magnetic flux density at any magnetic pole radius. Furthermore, the end-effect compensation function is obtained. In order to investigate the effectiveness of the proposed method, the results calculated by the analytical method are compared with the finite element method. It is shown that the novel method proposed in this paper is highly consistent with the air gap flux density calculated by the finite element method.

This paper deals with the modelling of traction linear induction motors (LIMs) for public transportation. The magnetic end effect inherent to these motors causes an asymmetry of their phase impedances. Thus, if the LIM is supplied from the three-phase symmetrical voltage, its phase currents become asymmetric. This effect must be taken into consideration when simulating the LIMs’ performance. Otherwise, when the motor phase currents are assumed to be symmetric in the simulation, the simulation results are in error. This paper investigates the LIM performance, considering the end-effect induced asymmetry of the phase currents, and presents a comparative study of the LIM performance characteristics in both the voltage and the current mode.