*2.3. LTS with Synchronous Motors*

Various levitated LTSs using conventional synchronous motors based propulsion were described in [19], e.g., they are permanent-magnet-excited machines. A high-temperature superconducting linear synchronous motor was described in [20]. The application of superconducting linear flux-switching permanent magnet motors was discussed in [21].

#### *2.4. LTS with Induction Motors*

Linear induction machines were discussed as the most promising solution for LTSs in [1,15,17,18]. In the late 1940s, the British electrical engineer Eric Laithwaite, Professor at Imperial College London, developed the first full-size working prototype of the linear induction motor. The first commercial Maglev transport system in the world, the Birmingham Maglev, which opened in 1984, was also propelled with a linear induction motor. The latest problems related to the application of LIMs are discussed in Section 3.
