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This paper provides an overview of the Linear Transportation System (LTS) and focuses on the application of a Linear Induction Motor (LIM) as a major constituent of LTS propulsion. Due to their physical characteristics, linear induction motors introduce many physical phenomena and design constraints that do not occur in the application of the rotary motor equivalent. The efficiency of the LIM is lower than that of the equivalent rotary machine, but, when the motors are compared as integrated constituents of the broader transportation system, the rotary motor’s efficiency advantage diminishes entirely. Against this background, several solutions to the problems still existing in the application of traction linear induction motors are presented based on the scientific research of the authors. Thus, solutions to the following problems are presented here: (a) development of new analytical solutions and finite element methods for LIM evaluation; (b) comparison between the analytical and numerical results, performed with commercial and self-developed software, showing an exceptionally good agreement; (c) self-developed LIM adaptive control methods; (d) LIM performance under voltage supply (non-symmetrical phase current values); (e) method for the power loss evaluation in the LIM reaction rail and the temperature rise prediction method of a traction LIM; and (f) discussion of the performance of the superconducting LIM. The addressed research topics have been chosen for their practical impact on the advancement of a LIM as the preferred urban transport propulsion motor.

This paper deals with the optimal design of a new synchronous motor particularly suitable for electric vehicles. The unique advantage of this motor is its possibility to realize field weakening at high speeds, which is the most important demand for such drives. The main design goal is to identify the dimensions of certain crucial regions of the machine in order to avoid saturation of the iron and to minimize the mass to volume ratio, while simultaneously maximizing the torque. The originality of the contribution is manifold: formulating the design problem in multiobjective terms, solving it by means of evolutionary computing, solving the associated direct problem based on a three-dimensional finite element analysis (3-D-FEA) field model, considering a reduced set of design variables by means of response surface method, referring to a real-life problem.

This paper proposes a topology optimization method, which allows to design a permanent magnet (PM) excited machine with improved high-speed features, incorporating the topological gradient into the multi-level set method with total variation regularization. It involves the design of both the stator and the rotor, the shape of which has a predominant impact on the mechanical and electric features of a PM machine. The concept of the topological gradient is incorporated for the nucleation of new holes in the distribution of level sets. The essential advantage of the proposed method is its ability to handle topology change on a fixed mesh and its flexibility in terms of shape changing that leads to efficient computational schemes. Finally, 2/3-D models are developed and deeply analyzed to indicate that the applied method leads to a significant reduction of both the cogging torque and the amount of higher back EMF harmonics.

The ability of high temperature superconducting bulks to trap magnetic fields of several tesla allows them to generate very high levitation force. This paper reports the development of a bulk-bulk superconducting rotary bearing design which uses superconducting bulks on both the rotor and the stator. An evaluation is made of the effectiveness of pulsed fields for magnetizing bulks. Modeling of the bulks using the perfectly trapped flux model is also reported to assess the limits of the bearing design. The results demonstrate the feasibility of a (RE)BCO-MgB2 bulk bearing capable of force densities of the order of 100N/cm2. The design and construction of a unique system capable of magnetizing a 25mm (RE)BCO bulk and measuring levitation force between this bulk and a coaxial MgB2 hollow cylinder is outlined

In this study, the design optimisation of a switched reluctance machine (SRM) with the layered method has been studied. Firstly, a multi‐physical analytical model for the SRM is established. The proposed model consists of an electromagnetic model, an electrical model, a loss model, and a thermal model. Then a layered optimisation design method suitable for the SRM is proposed in combination with the multi‐physical field simulation model. Taguchi method is used to analyse the influence degree of the main geometric dimensions on the dynamic performance, and the parameters are divided into high‐sensitivity parameters (HSPs) and low‐sensitivity parameters. The non‐dominated sorting genetic algorithm‐II algorithm is used to optimise the HSP by the proposed model. The iron loss, average torque, average torque per unit mass, torque ripple and efficiency are taken as the objective functions. Finally, the prototype is manufactured and a testing platform is built. The flux linkage of several special positions of the machine is verified experimentally, and the accuracy of the electromagnetic model in the multi‐physical field model is verified. The temperature experiments are carried out on the machine, and the accuracy of the equivalent heat circuit model in the multi‐physical field model is verified.