MAGLEV TRAINS

Magnetic Levitation

Magnetic levitation, maglev, or magnetic suspension is a method by which an object is suspended above another object with no support other than magnetic field .The electromagnetic force is used to counteract the effects of the gravitational force. A substance which is diamagnetic repels a magnetic field. All materials have diamagnetic properties, but the effect is very weak, and usually overcome by the object's paramagnetic or ferromagnetic properties, which act in the opposite manner. Any material in which the diamagnetic component is strongest will be repelled by a magnet, though this force is not usually very large.

Maglev Methods

v Repulsion between like poles of permanent magnets or electromagnets.

v Repulsion between a magnet and a metallic conductor induced by relative motion.

v Repulsion between a metallic conductor and an AC electromagnet.

Electrodynamic Suspension (Eds) System

        In the EDS-repulsive system, the superconducting magnets (SCMs), which do the levitating of the vehicle, are at the bottom of the vehicle, but above the track. The track or roadway is either an aluminum guideway or a set of conductive coils. The magnetic field of the superconducting magnets aboard the maglev vehicle induces an eddy current in the guideway. The polarity of the eddy current is same as the polarity of the SCMs onboard the vehicle. Repulsion results, "pushing" the vehicle away and thus up from the track.

Principle Of Linear Motor

        However, this raises a frequently asked question: where is the motor or engine in the maglev system? There is a motor. The motor of a maglev system is the interaction between the electromagnets/superconducting magnets (SCMs) and the guideway; the package of the two, and their interaction is what constitutes the motor. Otherwise, there is no standing motor aboard, as in the case of train locomotive or automobile engine. In a normal conventional motor, there are two principal parts: the stator, which is stationary; and the rotor, which can rotate as a result of action from the stator.

Inductrack

        The Inductrack is a newer type of EDS that uses permanent room-temperature magnets to produce the magnetic fields instead of powered electromagnets or cooled superconducting magnets. Inductrack uses a power source to accelerate the train only until begins to levitate. If the power fails, the train can slow down gradually and stop on its auxiliary wheels.

Conclusion

        It’s no longer science fiction, maglev trains are the new way of transportation in the near future, just some obstacles are in the way, but with some researches nothing is impossible.