Electromagnetic Investigation of a High-Temperature Superconducting Linear Synchronous Motor for High-Speed Railway

High-temperature superconducting (HTS) linear synchronous motor (LSM) with low power loss, high thrust density, and large mechanical gap, makes it a promising candidate for driving the future high-speed rail transit and even ultrahigh-speed magnetic levitation (Maglev) vehicle. However, superconducting magnet can produce strong enough magnetic field, which will inevitably lead to the saturation of stator iron and generate significantly attractive force between the stator and the on-board HTS magnet. Therefore, a coreless-typed HTS LSM has attracted much attention in recent years. This paper, served as a fundamental study on a linearly driven system for rail transit or Maglev, is aimed to investigate the electromagnetic properties of an HTS LSM, by means of numerical modeling, experiment, and analytic model. First, a two-dimensional (2-D) finite element model was established. Then, a force-measuring system, being able to measure the 3-D forces of motor, was fabricated. Finally, a set of analytic expressions to describe the magnetic field distribution of coreless-typed LSM, were derived, which was verified by comparing with a finite element model and ultimately tailored to study the electromagnetic properties of the coreless-typed HTS LSM.