duction motor until it is flat. This presentation will explain the qualitative nature of the LIM, without going into the complicated mathematical and physical derivations. We will focus on a three-phase LIM.A LIM consists of two parts, a stator, and a rotor. The stator and rotor consist of magnetically permeable material such as iron. Within the stator, three wires are embedded. Each wire weaves through the stator in a special periodic pattern. In the diagram below, the wires are perpendicular to the plane of the computer screen.Each wire is connected to a sinusoidal current source. The three currents are each 120 degrees out of phase with each other. This setup is called a three-phase current source.The pattern used with a three phase current source is this: ---A C' B A' C B'--- Each letter represents a wire. A and A' represent the wire that carries current Ia. A and A' carry the same current, but point in opposite directions. The same conventions apply to B, B' and C, C'.This configuration is very useful because it allows the stator to create a moving magnetic field.This moving magnetic field induces currents in the rotor. These induced currents, at any instaneous time, oppose the change in the magnetic field, in accordance with Faraday's Law.These induced currents then interact with the moving magnetic field, resulting in a force that moves the rotor along with the moving magnetic field in the stator.DiscussionLIM's have the ability to move the rotor relative to the stator without any physical contact. This drastically reduces wear and tear on the parts involved and eliminates frictional forces that cause inefficiency.LIM's have the ability to accelerate the rotor from rest up to the speed of the moving magnetic field. Linear Synchronous MotorsLSM's are structurally very similar to LIM's except for one change. The behavior of the two types of linear motors is changed significantly.Both LIM's and LSM's consist of a stator and rotor. B...
