A comparison of linear induction and linear synchronous motors for high speed ground transportation

Preliminary designs for full-scale (3750 kW) linear synchronous traction motors of both the claw pole (Lundell) and the homopolar inductor types are compared with the LIMRV motor, a full-scale linear induction motor which has recently undergone high-speed testing. These designs show the homopolar inductor to be the favored linear synchronous motor with a predicted improvement in power factor, efficiency, and power density when compared to the linear induction motor. No-load test results from a 112 kW homopolar inductor test motor are presented which in general confirm the predicted advantages of the homopolar inductor design.