22-12-2010, 03:54 PM
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1. INTRODUCTION
It’s a form of transportation that suspends ,guides and propels vehicles via electromagnetic force. This method can be faster and more comfortable than wheeled mass transit systems. Maglevs could potentially reach velocities comparable to turbo prop and jet aircraft (500 to 580km/hr).
Maglev Technology has minimal overlap with wheeled train technology and is not compatible with conventional rail road tracks. Because they cannot share existing infrastructure , maglevs must be designed as complete transportation system.The term “MAGLEV” refers not only to the vehicles but to the vehicle/guideway interaction each being a unique design element specifically tailored to the other to create and precisely control magnetic levitation.
Due to the lack of physical contact between the track and the vehicle, the only friction exerted is that between the vehicles and the air. Consequently, maglevs can potentially travel at very high speeds with reasonable energy consumption and noise levels. Systems have been proposed that operate at up to 659km/hr(404mph) which is faster than is practical with conventional rail transport. The very high maximum speed potential of maglevs make them competitors to airline routers of 1,000 kilometer(600 miles) or less.
2. TWO BASICALLY DIFFERENT CONCEPTS OF MAGNETIC SUSPENSION HAVE EVOLVED,
The attractive electromagnetic suspension (EMS) uses electromagnetic on the train body which are attracted to the iron rails. The vehicle magnets wrap around the iron guideways and the attractive upward force lifts the train.
The electrodynamics suspension (EDS) levitates the train by repulsive forces from the induced current in the conductive guide ways.
3. WHAT IS LEVITATION ?
LEVITATION (from Latin levis, light) is the process by which an object is suspended against the gravity, in a stable position, by a force without physical contact.
LEVITATION is the raising of a human or other object in the air without any mechanical aid.
THREE TYPES OF MAGLEV TECHNOLOGY
There are three primary types of maglev technology,
1. ELECTROMAGNETIC SUSPENSION (EMS) relies on feedback controlled electromagnets.
Example: Transrapid
2. ELECTRODYNAMIC SUSPENSION (EDS) relies superconducting magnets.
Example: JR-Maglev
3. INDUCTRACK RELIES on permagnets.
4. PROS AND CONS OF DIFFERENT TECHNOLOGY
Each implementation of the Magnetic Levitation principle for train type travel involves advantages as well as disadvantages.
5. THEORY:
The Inductrack and the Superconductivity EDS are only
levitation technologies. In both cases,vehicles need some other technology for propulsion. A Jet Engine and a linear motor are being considered, such as the linear motor used for propulsion in the Japanese Superconducting EDS MLXOI Maglev.
The German Transrapid Electromagnetic Maglev uses a linear motor for both levitation and propulsion. Neither Inductrack provides levitation down to a much lower speed. Wheels are required for both systems. EMS systems are wheel-less.
The German Transrapid Japanese HSST(linnimo) and Korean Rotem Maglevs levitate at a standstill, with electricity extracted wirelessly for Transrapoid .If guideway power is lost on the move, the Transpoid is still able to generate levitations down to 10km/hr speed, using the power from onboard batteries. This is not the case with the HSST and Rotem systems
