How have Superconductors and the effects of magnetic fields been applied to develop the maglev train?
Magnetic levitation (maglev) suspends an object so that is free of any surface contact. This has the effect of providing a frictionless contact with the ground, making it particularly appropriate for high speed trains. A typical Maglev train is streamlined to reduce air resistance and travels along a guide way, instead of using conventional train tracks. Once the train is levitated, by continually changing the polarity of alternate magnets along the track, a series of attractions and repulsions is generated that provides the force to overcome air resistance and accelerate the train along the guide way. The main obstacle encountered by the train during it’s motion is air resistance. The enormous amount of electrical power needed by the train is an obstacle to it’s wider use.
There are two types of Maglev trains:
The electromagnetic suspension system (Germany) uses conventional magnets under the train on structures that wrap around the guide way to provide the lift and to create the frictionless running surface. This system, however, is unstable, because of the varying distance between the magnets and the guide way. The instability needs to be monitored closely and computers have provided the control to correct the instability. The lifting force is produced by arrays of electromagnets of like polarity in both the train and the guide way. The magnets repel each other to lift the train above the track.
The electrodynamic suspension System (Japan) uses superconducting magnets on the vehicle and electrically conductive strips or coils on the guide way to levitate the train. This doesn’t require the same amount of computer monitoring adjustment while travelling, the requirement for very low temperatures means that, momentarily, this is not a practical system. The system for accelerating the train along a guide way is similar to the EMS system.
Electric generators made with superconducting wire are far more efficient than conventional generators wound with copper wire. In fact, their efficiency is above 99% and their size about half that of conventional generators. These facts make them very productive ventures for power utilities. Their ability to conduct electricity without losing power in heat make them very resourceful especially for Electrical transmission lines through power grids. Energy is lost due to the resistance of the wires. If a superconductor could be developed to function at a high temperature, very large quantities of electricity could be made to pass through finer wires… almost 3 to 5 times more electricity than conventional transmission lines.
This would be immensely cost efficient and would reduce the present imperative need for more power stations.
The use of superconducting magnets in motors and generators, will not need the iron core and would condense the size and mass of the mechanisms tremendously. Fossil fuel would be less necessary to produce electricity and would reduce the secretion of greenhouse gases and atmospheric contaminants from power plants.
Power storage: Power stations at present are not able to store electricity due to it’s high consumption rate. But Super conducting magnetic energy storage may be the solution to this setback. These facilities employ a large ring structure assembled by using a High Temperature Superconductor resource an refrigerators. Electrical energy in the form of a DC current can be introduced to the system. The reason why DC current should be used is because the constant switching of direction in€ current produces some energy loss. The DC electrical current would then flow around the superconducting magnetic energy storage device’s circular path indefinitely without energy loss until it is required, whereupon it can be retrieved and converted into AC current for delivery to domestic and industrial consumers. Alternatively, it could be transported by using byy superconducting transmission system as DC. The big advantage of the SMES system is that power generation can operate continuously at peak efficiency levels no matter whether the demand is at a maximum or minimum. This minimises the need for more power stations and potentially opens the way for the use of large-scale solar power stations with energy produced during the day and stored for 24hr use.
Superconductivity can also be applied to electronic devices such as computers. The shrinking of computer chips are is limited by the generation of heat, due to the resistance of the electrical flow required to make them run, as well as by the speed with which signals can be conducted. Superconducting film, used as connecting conductors, may result in more densely packed conductor chips. These could transmit information a lot faster.