Traditionally, straggering the primaries of the double-sided permanent magnet linear synchronous motor (DS-PMLSM) is beneficial in helping to reduce the detent force caused by the longitudinal end effect, but leading to a reduction of the average thrust. To overcome this disadvantage, this paper provides a novel DS-PMLSM, which adopts the structure of staggering two primaries and rearranging windings. Firstly, the characteristics of the voltage and detent force are analyzed theoretically and verified by finite element (FEM) simulations. The inductance, thrust and normal forces are then compared with the traditional DS-PMLSM. Furthermore, the geometrical parameters are optimized to improve the thrust. Finally, one DS-PMLSM prototype is tested. The detent force and back EMF tested results verify the effectiveness of the topology proposed in this research.

The intelligent annular transmission system driven by permanent magnet synchronous linear motor (PMSLM) is composed of linear and arc segments. When the mover enters the arc segment from the straight segment, the coupling area between the primary and secondary becomes smaller. It results in that the average thrust decreases and the thrust ripple increases. This phenomenon affects the control accuracy and operation reliability. This paper focuses on the research on the arc permanent magnet synchronous motor (A-PMSM) in the arc segment of the annular transmission system. The equivalent magnetic network model of A-PMSM is established. The air-gap coefficient is used to compare the slot effect of arc primary structure with that of straight primary structure. The influence of arc radius and radial width on the slot effect of A-PMSM with linear mover is obtained. The structure of magnetic pole, the radial width of secondary and the slot width are optimized by the combination of hierarchical optimization and orthogonal optimization. The A-PMSM's performance of thrust is optimized, which provides experience for the design of the motor in the annular transmission system.

Permanent magnet linear synchronous motor (PMLSM) has a wide application prospect in transmission systems of automatic production, logistics, and other fields. However, the existing PMLSM has the problems of poor flexibility and large thrust fluctuation adapted to load and stroke variation. In order to solve this problem, a dual-modular PMLSM is proposed. The motor can be flexibly configured with multiple-unit-primary and multiple-unit-secondary, and achieve low thrust fluctuation. The matching criterion of unit-primary (UP) and secondary is established to reveal the relationship between the slot/pole combination and the winding utilization. The rules of the average thrust varying with the different UP and unit-secondary (US) lengths are illustrated. Then, the matching criterion of different UP is proposed, and the optimization method of the spacing between UP ( S ₁ ) is obtained by establishing the end force model. The design standard of the optimal S ₁ is obtained by combining the two factors of minimum detent force and maximum thrust. The results are verified by the simulation and experiments on a 3UP-96US dual-modular PMLSM circular transmission line system and its prototype.

In order to improve the performance of the linear motor system, it is necessary to adopt a simple motor structure and effective optimisation method to reduce the detent force without decreasing the average thrust. A 16‐pole 18‐slot two‐sectional modular permanent magnet linear synchronous motor (PMLSM) is investigated in this study, in which the primary core is divided into two modules and coupled with the secondary, forming two sections. It is found that the modular distance between the two sections affects the detent force and back‐electromotive force of the whole motor. Thus, the characteristics of the detent force and the categories of the winding arrangements are analysed. The modular distance of 4 τ /9 is chosen after analysis and comparison. To further suppress the detent force and improve the average thrust, a new end tooth structure including different wide and narrow tooth is proposed, which is set at the ends of each section's primary core. The design method of the end tooth parameters is obtained by theoretical derivation and the optimisation efficiency of end tooth parameters is further improved by layered optimisation design. Finally, the experiments on the 16‐pole 18‐slot PMLSM validate the correctness and feasibility of the proposed modular motor structure.

This paper proposes a double-side long primary permanent magnet linear synchronous motor (PMLSM) that can operate in suspension. In this motor, the levitation subsystem and propulsion subsystem are decoupled in terms of both “electrical circuit” and “magnetic circuit”, resulting in lower system control complexity. For this motor, the normal force between the primary and secondary components is a major component of the motor's levitation force. The normal force ripple can hinder improvements in system positioning accuracy and operational stability. This paper investigates the characteristics of normal force ripple in this motor, establishes a model for local normal force calculation and simulation analysis, and reveals the influence mechanism of end effects and armature reactions on the normal force ripple. Based on this, an optimized design solution for split-ended magnetic pole is proposed, effectively suppressing normal force ripple, both locally and whole. Finally, for a 24-slot 8-pole prototype, finite element simulation and experimental tests are conducted. The results show that no normal force ripple in both local and whole aspects of the motor, validating the theoretical research presented in this paper.