Comparison of combined versus separate lift/propulsion systems

The notion of using the magnetic attractive force of a single-sided linear induction motor (SLIM) for suspension of a vehicle has recently received some attention. There is, therefore, some interest in determining how such a combined suspension/propulsion system would compare to separate lift and propulsion. Weight requirements of transverse flux dc lift magnets are calculated as a function of vehicle weight and magnet length. A three-phase longitudinal flux linear motor/suspension system is designed which has the same values of maximum flux and current density as the dc magnet. The effect of pole pitch on the weight of this motor is shown. Comparisons are made between this combined system and a system using the dc magnets plus a separate linear motor.