Electric railway traction - Applications of linear motors

As we shall see in the history of railway applications of linear motors, there is already an abundance of literature on the principles used and their applications in research, development and testing.

For this reason, we won't go into detail on the principles and calculations, which are very well explained in the [D 3 700] file "Electric motors with linear and compound motion", except of course if the successful application calls for particularly novel arrangements or combinations of functions other than traction and braking, which is the most frequent case of guided systems with magnetic levitation in particular. However, these systems depend on guide or carrier rails, and often on wheels, when the magnetic support elements are not in action, and sometimes even when the linear drive parts are. That's why we're also talking about applications known as "Maglev" (Magnetic Levitation), which covers the two main systems known as "attraction" ("Transrapid" of German origin) or "repulsion" ("Maglev" of Japanese origin). These systems all use the two main types of linear motorization, synchronous or asynchronous, on magnetically-rail-bound track.

After a review of the choice of motors and their power supply, whether mobile, track-mounted or a combination of the two, commercial applications will enable us to differentiate between low-speed systems for short services with numerous stops and high frequencies, and high-speed systems for long distances between stops. Finally, we'd like to mention special prototypes and research still in progress, or still... waiting to evolve.