Department Of Physics
University Of Jaffna
Special Degree in Physics
Library Work Report of
Operation of Maglev Train
3.1 Basic Idea…………………………………………………………………9
3.2 The two notable types of maglev technology……………………………10
3.3 The three primary functions in maglev technology………………………15
4.0 History of maglev speed records………………………………………………19
5.0 Comparison with conventional trains………………………………………..20
6.0 Comparison with aircraft………………………………………………………22
7.0 Advantages and Disadvantages of Maglev…………………………………..22
1.0 Introduction2943225427609029432252409190Magnetic levitation (maglev) is a highly advanced technology. It is used in the various cases, including clean energy (small and huge wind turbines: at home, office, industry, etc.), building facilities (fan), transportation systems (magnetically levitated train, Personal Rapid Transit (PRT), etc.), weapon (gun, rocketry), nuclear engineering (the centrifuge of nuclear reactor), civil engineering (elevator), advertising (levitating everything considered inside or above various frames can be selected), toys (train, levitating spacemen over the space ship, etc.), stationery (pen) and so on. The common point in all these applications is the lack of contact and thus no wear and friction. This increases efficiency, reduce maintenance costs and increase the useful life of the system. The magnetic levitation technology can be used as a highly advanced and efficient technology in the various industrial. There are already many countries that are attracted to maglev systems.
29432251901190Figure SEQ Figure * ARABIC 1: Maglev Train
Figure SEQ Figure * ARABIC 1: Maglev Train
Among above-mentioned useful usages, the most important usage of magnetic levitation is in operation of magnetically levitated trains. Magnetically levitated trains are undoubtedly the most advanced vehicles currently available to railway industries. Maglev is the first fundamental innovation in the field of railroad technology since the invention of the railroad. Magnetically levitated train is a highly modern vehicle. Maglev vehicles use noncontact magnetic levitation, guidance and propulsion systems and have no wheels, axles and transmission. Contrary to traditional railroad vehicles, there is no direct physical contact between maglev vehicle and its guide way. These vehicles move along magnetic fields that are established between the vehicle and its guide way. Conditions of no mechanical contact and no friction provided by such technology makes it feasible to reach higher speeds of travel attributed to such trains. Manned maglev vehicles have recorded speed of travel equal to 581km/hr. The replacement of mechanical components by wear-free electronics overcomes the technical restrictions of wheel-on-rail technology. Application of magnetically levitated trains has attracted numerous transportation industries throughout the world. Magnetically levitated trains are the most recent advancement in railway engineering specifically in transportation industries. Maglev trains can be conveniently considered as a solution for transportation needs of the current time as well as future needs of the world. There is variety of designs for maglev systems and engineers keep revealing new ideas about such systems. Many systems have been proposed in different parts of the worlds, and a number of corridors have been selected and researched.1
Rapid growth of populations and the never ending demand to increase the speed of travel has always been a dilemma for city planners. The future is already here. Rapid transit and high-speed trains have always been thought of and are already in use. This is the way further into the future. Trains with magnetic levitations are part of the game. Conventional railway systems have been modified to make them travel at much higher speeds. Also, variety of technologies including magnetic levitation systems and high-speed railway (HSR) systems has been introduced. Rapid development of transportation industries worldwide, including railroads and the never ending demand to shorten travel time during trade, leisure, etc. have caused planning and implementation of high-speed railroads in many countries. Variety of such systems including maglev has been introduced to the industry. Maglev trains are a necessity for modern time transportation needs and vital for the future needs of railways, worldwide. This has resulted in the development of a variety of maglev systems that are manufactured by different countries. Maglev systems currently in use have comparable differences. The current models are also changing and improving.
190503538220Figure SEQ Figure * ARABIC 2: Maglev Train
Figure SEQ Figure * ARABIC 2: Maglev Train
190501537970Industries have to grow in order to facilitate many aspects of modern day life. This comes with a price to pay for by all members of societies. Industrial developments and widespread use of machineries have also increased risks of financial damages and loss of lives. Safety and needs to physically protect people against machineries may have not been a priority in the past but they are necessities of modern times. Experts of industries have the task of solving safety and protection issues before implementing machineries. This is a step with high priority for all industrial assignments. While being fast, reliable and comfortable, maglev systems have found special places in minds of people. Running at such high speeds, maglev systems have to be safe and need to be renown for safety. This puts much heavier loads on the shoulders of the corresponding experts and managers, compared to some other means of transportation. Safety is knowingly acting with proper functions to provide comfort and reduce dangers, as much as possible. Risk management techniques have a vital role in organizing and implementing proper acts during incidents, accidents or mishaps in maglev systems operations. Effective management has a specific place in such processes. Obviously, such plannings put considerable financial load on the system. Implementation of internationally accepted standards is a fundamental step toward uplifting track safety. It will also serve to improve route quality, increase passenger loads and increase speed of travel. Maglev vehicle is one of the important transportation equipment of the urban track traffic system toward the future.
The overall plan for research and development and application of maglev technology should be made at the national level. This plan shall include the development plans as to research and development of key maglev technology, project implementing technology research and development of maglev project, plans of building maglev passage based on traffic demands, investment and financing system for the construction and operation of maglev system, research on implementing plans of high-density operational organization and maintenance of maglev route and so on.
It is very important to be vigilant about economical aspects of any major project during its planning and construction phases. Optimal use of local resources must be all accounted for. Technical and economical evaluation of the projects is a necessity to their success. It is necessary to have prior knowledge for investing into a project and then implementing its goals. Good planning makes it feasible to run the projects with reduced risks and increased return for the investment.2
2.1 First Maglev patent
High-speed transportation patents were granted to various inventors throughout the world. Early United States patents for a linear motor propelled train were awarded to German inventor Alfred Zehden. The inventor was awarded U.S. Patent 782,312(14 February 1905) and U.S. Patent RE12,700 (21 August 1907). In 1907, another early electromagnetic transportation system was developed by F. S. Smith.A series of German patents for magnetic levitation trains propelled by linear motors were awarded to Hermann Kemper between 1937 and 1941. An early maglev train was described in U.S. Patent 3,158,765, “Magnetic system of transportation”, by G. R. Polgreen (25 August 1959). The first use of “maglev” in a United States patent was in “Magnetic levitation guidance system”, by Canadian Patents and Development Limited.3
34575751659890Figure SEQ Figure * ARABIC 3: New York, United State
Figure SEQ Figure * ARABIC 3: New York, United State
345757597790 2.2 New York, United States, 1968
In 1968, while delayed in traffic on the Throgs Neck Bridge, James Powell, a researcher at Brookhaven National Laboratory (BNL), thought of using magnetically levitated transportation. Powell and BNL colleague Gordon Danby worked out a MagLev concept using static magnets mounted on a moving vehicle to induce electro dynamic lifting and stabilizing forces in specially shaped loops, such as figure of 8 coils on a guide way.
32956502105025Figure SEQ Figure * ARABIC 4: Hamburg, Germany
Figure SEQ Figure * ARABIC 4: Hamburg, Germany
3295650352425 2.3 Hamburg, Germany, 1979
Transrapid 05 was the first maglev train with long stator propulsion licensed for passenger transportation. In 1979, a 908 m (2,979 ft) track was opened in Hamburg for the first International Transportation Exhibition (IVA 79). Interest was sufficient that operations were extended three months after the exhibition finished, having carried more than 50,000 passengers. It was reassembled in Kassel in 1980.
2.4 Birmingham, United Kingdom, 1984–95
The world’s first commercial maglev system was a low-speed maglev shuttle that ran between the airport terminal of Birmingham International Airport and the nearby Birmingham International railway station between 1984 and 1995. Its track length was 600 m (2,000 ft), and trains levitated at an altitude of 15 mm (0.59 in), levitated by electromagnets, and propelled with linear induction motors. It operated for 11 years and was initially very popular with passengers, but obsolescence problems with the electronic systems made it progressively unreliable as years passed, leading to its closure in 1995. One of the original cars is now on display at Rail world in Peterborough, together with the RTV31 hover train vehicle. Another is on display at the National Railway Museum in York.
Several favourable conditions existed when the link was built:
34099502204085Figure SEQ Figure * ARABIC 5: Birmingham, United Kingdom
Figure SEQ Figure * ARABIC 5: Birmingham, United Kingdom
3409950118110The British Rail Research vehicle was 3 tonnes and extension to the 8 tonne vehicle was easy.
Electrical power was available.
The airport and rail buildings were suitable for terminal platforms.
Only one crossing over a public road was required and no steep gradients were involved.
Land was owned by the railway or airport.
Local industries and councils were supportive.
Some government finance was provided and because of sharing work, the cost per organization was low.
After the system closed in 1995, the original guide way lay dormant14 until 2003, when a replacement cable-hauled system, the Air Rail Link Cable Liner people mover, was opened.
35337751697990Figure SEQ Figure * ARABIC 6: Emsland, Germany
Figure SEQ Figure * ARABIC 6: Emsland, Germany
3533775316865 2.5 Emsland, Germany, 1984–2012
Transrapid, a German maglev company, had a test track in Emsland with a total length of 31.5 km (19.6 mi). The single-track line ran between Dörpen and Lathen with turning loops at each end. The trains regularly ran at up to 420 km/h (260 mph). Paying passengers were carried as part of the testing process. The construction of the test facility began in 1980 and finished in 1984. In 2006, the Lathen maglev train accident occurred killing 23 people, found to have been caused by human error in implementing safety checks. From 2006 no passengers were carried. At the end of 2011 the operation licence expired and was not renewed, and in early 2012 demolition permission was given for its facilities, including the track and factory.
2.6 Japan, 1969–present
33051752615565Figure SEQ Figure * ARABIC 7: Japan
Figure SEQ Figure * ARABIC 7: Japan
3305175681990Japan operates two independently developed maglev trains. One is HSST (and its descendant, the Linimo line) by Japan Airlines and the other, which is more wellknown, is SCMaglev by the Central Japan Railway Company.
The development of the latter started in 1969. Miyazaki test track regularly hit 517 km/h (321 mph) by 1979. After an accident that destroyed the train, a new design was selected. In Okazaki, Japan (1987), the SCMaglev took a test ride at the Okazaki exhibition. Tests through the 1980s continued in Miyazaki before transferring to a far larger test track, 20 km (12 mi) long, in Yamanashi in 1997.
Development of HSST started in 1974. In Tsukuba, Japan (1985), the HSST-03 (Linimo) became popular in spite of its 30 km/h (19 mph) at the Tsukuba World Exposition. In Saitama, Japan (1988), the HSST-04-1 was revealed at the Saitama exhibition performed in Kumagaya. Its fastest recorded speed was 300 km/h (190 mph).
2.7 Vancouver, Canada and Hamburg, Germany, 1986–88
In Vancouver, Canada, the HSST-03 by HSST Development Corporation (Japan Airlines and Sumitomo Corporation) was exhibited at Expo 8619 and ran on a 400-metre (0.25 mi) test track that provided guests with a ride in a single car along a short section of track at the fairgrounds. It was removed after the fair and debut at the Aoi Expo in 1987 and now on static display at Okazaki Minami Park. In Hamburg, Germany, the TR-07 was exhibited at the international traffic exhibition (IVA88) in 1988.
30765752371090Figure SEQ Figure * ARABIC 8: Berlin, Germany
Figure SEQ Figure * ARABIC 8: Berlin, Germany
3076575351790 2.8 Berlin, Germany, 1989–91
In West Berlin, the M-Bahn was built in the late 1980s. It was a driverless maglev system with a 1.6 km (0.99 mi) track connecting three stations. Testing with passenger traffic started in August 1989, and regular operation started in July 1991. Although the line largely followed a new elevated alignment, it terminated at Gleisdreieck U-Bahn station, where it took over an unused platform for a line that formerly ran to East Berlin. After the fall of the Berlin Wall, plans were set in motion to reconnect this line (today’s U2). Deconstruction of the M-Bahn line began only two months after regular service began.
2.9 South Korea, 1993–present
In 1993, Korea completed the development of its own maglev train, shown off at the Taejon Expo ’93, which was developed further into a full-fledged maglev capable of travelling up to 110 km/h (68 mph) in 2006. This final model was incorporated in the Incheon Airport Maglev which opened on February 3, 2016, making Korea the world’s fourth country to operate its own self-developed maglev after the United Kingdom’s Birmingham International Airport, Germany’s Berlin M-Bahn, and Japan’s Linimo. It links Incheon International Airport to the Yongyu Station and Leisure Complex on Yeongjong island. It offers a transfer to the Seoul Metropolitan Subway at AREX’s Incheon International Airport Station and is offered free of charge to anyone to ride, operating between 9 am and 6 pm with 15 minute intervals. Operating hours are to be raised in the future.
30384751564005Figure SEQ Figure * ARABIC 9: South Korea
Figure SEQ Figure * ARABIC 9: South Korea
3038475-674370The maglev system was co-developed by the Korea Institute of Machinery and Materials (KIMM) and Hyundai Rotem. It is 6.1 kilometers (3.8 mi) long, with six stations and a 110 km/h (68 mph) operating speed.4
3.1 Basic Idea
31908752731135Figure SEQ Figure * ARABIC 10: Basic Idea
Figure SEQ Figure * ARABIC 10: Basic Idea
319087516510A common type of magnet is a dipole. It has North Pole (N) and South Pole (S). Principle of magnetism simply states that like poles repel and opposite poles attract. Maglev uses the same principle to lift the train above the guide way. However, the magnetic field in this case is not entirely coming from permanent magnets, but it is created by electric current that is induced through the train and guide way. It creates temporary magnetic force and temporary magnetic poles. Also, Maglev uses the principle of linear induction and magnetism to propel the train forward or backward. The combination of repulsive and attractive magnetic forces causes the train to levitate and move forward. When the current changes direction, the poles also change and the repulsive and attractive forces act opposite from when the motion started. It causes the train to move backward. Generally, Maglev will be operated functionally if it goes through these three processes; levitation, propulsion and guidance.5
3.2 The two notable types of maglev technology are:
3.2.1 Electromagnetic suspension (EMS)
If you’ve ever played with magnets, you know that opposite poles attract and like poles repel each other. This is the basic principle behind electromagnetic propulsion. Electromagnets are similar to other magnets in that they attract metal objects, but the magnetic pull is temporary. As you can read about in How Electromagnets Work, you can easily create a small electromagnet yourself by connecting the ends of a copper wire to the positive and negative ends of an AA, C or D-cell battery. This creates a small magnetic field. If you disconnect either end of the wire from the battery, the magnetic field is taken away.
32099252788920Figure SEQ Figure * ARABIC 11: Electromagnetic suspension (EMS)
Figure SEQ Figure * ARABIC 11: Electromagnetic suspension (EMS)
320992526670The magnetic field created in this wire-and-battery experiment is the simple idea behind a maglev train rail system. There are three components to this system:
A large electrical power source
Metal coils lining a guideway or track
Large guidance magnets attached to the underside of the train
The big difference between a maglev train and a conventional train is that maglev trains do not have an engine at least not the kind of engine used to pull typical train cars along steel tracks. The engine for maglev trains is rather inconspicuous. Instead of using fossil fuels, the magnetic field created by the electrified coils in the guideway walls and the track combines to propel the train.
In electromagnetic suspension (EMS) systems, the train levitates above a steel rail while electromagnets, attached to the train, are oriented toward the rail from below. The system is typically arranged on a series of C-shaped arms, with the upper portion of the arm attached to the vehicle, and the lower inside edge containing the magnets. The rail is situated inside the C, between the upper and lower edges.
Magnetic attraction varies inversely with the cube of distance, so minor changes in distance between the magnets and the rail produce greatly varying forces. These changes in force are dynamically unstable – a slight divergence from the optimum position tends to grow, requiring sophisticated feedback systems to maintain a constant distance from the track, (approximately 15 mm (0.59 in)).
24193502838450Figure SEQ Figure * ARABIC 12: Electromagnetic suspension (EMS)
Figure SEQ Figure * ARABIC 12: Electromagnetic suspension (EMS)
241935047625The major advantage to suspended maglev systems is that they work at all speeds, unlike electrodynamic systems, which only work at a minimum speed of about 30 km/h (19 mph). This eliminates the need for a separate low-speed suspension system, and can simplify track layout. On the downside, the dynamic instability demands fine track tolerances, which can offset this advantage. Eric Laithwaite was concerned that to meet required tolerances, the gap between magnets and rail would have to be increased to the point where the magnets would be unreasonably large. In practice, this problem was addressed through improved feedback systems, which support the required tolerances.6
188.8.131.52 The Maglev Track
28575002933700Figure SEQ Figure * ARABIC 13: The Maglev Track
Figure SEQ Figure * ARABIC 13: The Maglev Track
2857500857250The magnetized coil running along the track, called a guideway, repels the large magnets on the train’s undercarriage, allowing the train to levitate between 0.39 and 3.93 inches (1 to 10 cm) above the guideway. Once the train is levitated, power is supplied to the coils within the guideway walls to create a unique system of magnetic fields that pull and push the train along the guideway. The electric current supplied to the coils in the guideway walls is constantly alternating to change the polarity of the magnetized coils. This change in polarity causes the magnetic field in front of the train to pull the vehicle forward, while the magnetic field behind the train adds more forward thrust.
Maglev trains float on a cushion of air, eliminating friction. This lack of friction and the trains’ aerodynamic designs allow these trains to reach unprecedented ground transportation speeds of more than 310 mph (500 kph), or twice as fast as Amtrak’s fastest commuter train. In comparison, a Boeing-777 commercial airplane used for longrange flights can reach a top speed of about 562 mph (905 kph). Developers say that maglev trains will eventually link cities that are up to 1,000 miles (1,609 km) apart. At 310 mph, you could travel from Paris to Rome in just over two hours.
Germany and Japan are both developing maglev train technology, and both are currently testing prototypes of their trains. (The German company “Transrapid International” also has a train in commercial use — more about that in the next section.) Although based on similar concepts, the German and Japanese trains have distinct differences. In Germany, engineers have developed an electromagnetic suspension (EMS) system, called Transrapid. In this system, the bottom of the train wraps around a steel guideway. Electromagnets attached to the train’s undercarriage are directed up toward the guideway, which levitates the train about 1/3 of an inch (1 cm) above the guideway and keeps the train levitated even when it’s not moving. Other guidance magnets embedded in the train’s body keep it stable during travel. Germany has demonstrated that the Transrapid maglev train can reach 300 mph with people onboard.7
Electrodynamic suspension (EDS)
38290502726690Figure 14: Electrodynamic suspension (EDS)
Figure SEQ Figure * ARABIC 14: Electrodynamic suspension (EDS)
38290501059815 Japanese engineers are developing a competing version of maglev trains that use an electrodynamic suspension (EDS) system, which is based on the repelling force of magnets. The key difference between Japanese and German maglev trains is that the Japanese trains use super-cooled, superconducting electromagnets. This kind of electromagnet can conduct electricity even after the power supply has been shut off. In the EMS system, which uses standard electromagnets, the coils only conduct electricity when a power supply is present. By chilling the coils at frigid temperatures, Japan’s system saves energy. However, the cryogenic system uses to cool the coils can be expensive.
Another difference between the systems is that the Japanese trains levitate nearly 4 inches (10 cm) above the guideway. One potential drawback in using the EDS system is that maglev trains must roll on rubber tires until they reach a liftoff speed of about 62 mph (100 kph). Japanese engineers say the wheels are an advantage if a power failure caused a shutdown of the system. Germany’s Transrapid train is equipped with an emergency battery power supply. Also, passengers with pacemakers would have to be shielded from the magnetic fields generated by the superconducting electromagnets.
25717503052445Figure 15: Electrodynamic suspension (EDS)
Figure SEQ Figure * ARABIC 15: Electrodynamic suspension (EDS)
25717501395095In electrodynamic suspension (EDS), both the guideway and the train exert a magnetic field, and the train is levitated by the repulsive and attractive force between these magnetic fields. In some configurations, the train can be levitated only by repulsive force. In the early stages of maglev development at the Miyazaki test track, a purely repulsive system was used instead of the later repulsive and attractive EDS system. The magnetic field is produced either by superconducting magnets (as in JR–Maglev) or by an array of permanent magnets (as in Inductrack). The repulsive and attractive force in the track is created by an induced magnetic field in wires or other conducting strips in the track. A major advantage of EDS maglev systems is that they are dynamically stable – changes in distance between the track and the magnets creates strong forces to return the system to its original position. In addition, the attractive force varies in the opposite manner, providing the same adjustment effects. No active feedback control is needed.
However, at slow speeds, the current induced in these coils and the resultant magnetic flux is not large enough to levitate the train. For this reason, the train must have wheels or some other form of landing gear to support the train until it reaches take-off speed. Since a train may stop at any location, due to equipment problems for instance, the entire track must be able to support both low- and high-speed operation.
Another downside is that the EDS system naturally creates a field in the track in front and to the rear of the lift magnets, which acts against the magnets and creates magnetic drag. This is generally only a concern at low speeds (This is one of the reasons why JR abandoned a purely repulsive system and adopted the sidewall levitation system.) At higher speeds other modes of drag dominate.
The drag force can be used to the electrodynamic system’s advantage, however, as it creates a varying force in the rails that can be used as a reactionary system to drive the train, without the need for a separate reaction plate, as in most linear motor systems. Laithwaite led development of such “traverse-flux” systems at his Imperial College laboratory. Alternatively, propulsion coils on the guideway are used to exert a force on the magnets in the train and make the train move forward. The propulsion coils that exert a force on the train are effectively a linear motor: an alternating current through the coils generates a continuously varying magnetic field that moves forward along the track. The frequency of the alternating current is synchronized to match the speed of the train. The offset between the field exerted by magnets on the train and the applied field creates a force moving the train forward.8
Pros and Cons of Electromagnetic suspension (EMS) and Electrodynamic suspension (EDS)
Technology Pros Cons
Electromagnetic suspension (EMS). Magnetic fields inside and outside the vehicle are less than EDS; proven, commercially available technology; high speeds (500 km/h or 310 mph); no wheels or secondary propulsion system needed. The separation between the vehicle and the guide way must be constantly monitored and corrected due to the unstable nature of electromagnetic attraction; to the system’s inherent instability and the required constant corrections by outside systems may induce vibration.
Electrodynamic suspension (EDS). Onboard magnets and large margin between rail and train enable highest recorded speeds (603 km/h or 375 mph) and heavy load capacity; demonstrated successful operations using high temperature superconductors in its onboard magnets, cooled with inexpensive liquid nitrogen. Strong magnetic fields on the train would make the train unsafe for passengers with pacemakers or magnetic data storage media such as hard drives and credit cards, necessitating the use of magnetic shielding; limitations on guide way inductivity limit maximum speed; vehicle must be wheeled for travel at low speeds.
Table SEQ Table * ARABIC 1: Pros and Cons of Electromagnetic suspension (EMS) and Electrodynamic suspension (EDS)
3.3 The three primary functions in maglev technology
8953502092325Figure SEQ Figure * ARABIC 16: Primary functions in maglev technology
Figure SEQ Figure * ARABIC 16: Primary functions in maglev technology
It is important for the train to be able to stay suspended above the guideway so that Maglev can be operated. There are two important type of levitation:
Electromagnetic Suspension (EMS)
Electrodynamic Suspension (EDS)
Electromagnetic Suspension (EMS)
This system is arranged on a series of C-shaped arms. Upper part of the arm is attached to the vehicle (the train) and lower inside edge of the arm contains the electromagnet coil. The guideways is placed inside the arm with another electromagnet coil is attached at the bottom of it. The two coils with opposite poles are facing each other and create an attractive force as shown in Figure 17. Then, the attractive force causes the train to be pushed upward and thus, levitate. However, the magnetic attraction varies inversely with cube of distance. It means a slight distance changes between the train and the guide way, will produce a significantly varying force. So, a feedback system is created to maintain the optimum distance (approximately 15mm or 0.59in) between the train and the guide way.9
Figure SEQ Figure * ARABIC 17: Levitation in Electromagnetic Suspension (EMS)
Electro dynamic Suspension (EDS)
In this system, both the train and the guide way exert magnetic fields. The train is levitated by repulsive and attractive forces between these magnetic fields. These magnetic fields are created by superconducting magnets that are attached to the train and the guide way. Looking at Figure 18, the repulsive and attractive force is created by the induced magnetic field in the conducting coils in the system. Nonetheless, at slower speed (below 30 km/h or 19 mph), current induced in this coils and resultant magnetic flux are not large enough to levitate the train. So, wheels or other form of landing gears are installed to support the train until it reaches the take-off speed.10
266700158750Figure SEQ Figure * ARABIC 18: Levitation in Electro dynamic Suspension (EDS)
00Figure SEQ Figure * ARABIC 18: Levitation in Electro dynamic Suspension (EDS)
25908002657475Figure SEQ Figure * ARABIC 19: Propulsion
Figure SEQ Figure * ARABIC 19: Propulsion
2590800933450 In order for the train to move, a force that drives it forward is needed. Generally, a Maglev train does not have an engine. It uses electric linear motor to achieved propulsion. A normal motor will have a stator and a rotor. A stator is used to generate rotating magnetic field that induced rotating force on a rotor. As a result, the rotor will rotate. Likewise, linear motor is like an unrolled version of the normal motor as shown in Figure 19. In this motor, instead of having a rotating magnetic field, the stator creates the magnetic field across its length. Therefore, the rotor will experience a linear force that is pulled across the stator making the rotor moves forward in straight line.
29908502496820Figure SEQ Figure * ARABIC 20: Propulsion
Figure SEQ Figure * ARABIC 20: Propulsion
299085058420The concept is applied to the Maglev train. In this case, the train is the rotor and the guide way is the stator. As long as the guide way is induced with magnetic field, the train will move along its track. This system is called Linear Induction Motor (LIM). However, this system causes the train to be lag behind the guide way’s moving field and results in speed and energy losses. So, a new system called Linear Synchronous Motor (LSM) is introduced. The lag is removed by attaching a permanent magnet to the train to create its own static magnetic field. With addition of the magnet, the train travel in synchronize with the moving field. For a long run in traction, LIM is preferred and for short run, LSM is preferred.10
Guidance is important to keep the train to be centered over the guideway and prevent lateral displacement. Guidance system generally uses repulsive magnetic force to achieve the position intended. However, different levitation system has a different guidance.
184.108.40.206 Electromagnetic Suspension (EMS)
14001751059180 In this system, two electromagnetic coils are placed on the train, facing the sides of the guideways as shown in Figure 21. Repulsive magnetic force from both sides of the train keep the vehicle laterally on the guideway. Gap sensors are installed to detect changes in gap width so the current supplied to the guideway can be adjusted accordingly, allowing the train to shift back to the center.
122872510795Figure SEQ Figure * ARABIC 21: Guidance of Electromagnetic Suspension (EMS)
0Figure SEQ Figure * ARABIC 21: Guidance of Electromagnetic Suspension (EMS)
220.127.116.11 Electro dynamic Suspension (EDS)
14287501028700 In this system, guidance is coupled in the levitation system. Looking at Figure 22, propulsion coils are set on the left and right side of the guideway. When the train runs in the center of the guideway, induced electromotive force (EMF) cancel each other out. Through this connection, if the train moves closer to either side of the guideway, circulating current between these two coils is induced; as result, it creates a force that will push the train back to the center.10
1181100227965Figure SEQ Figure * ARABIC 22: Guidance of Electro dynamic Suspension (EDS)
0Figure SEQ Figure * ARABIC 22: Guidance of Electro dynamic Suspension (EDS)
4.0 History of maglev speed records
Year Country Train Speed
1971 West Germany Prinzipfahrzeug 90 km/h (56 mph)
1971 West Germany TR-02 (TSST) 164 km/h (102 mph)
1972 Japan ML100 60 km/h (37 mph)
1973 West Germany TR04 250 km/h (160 mph)
1974 West Germany EET-01 230 km/h (140 mph)
1975 West Germany Komet 401 km/h (249 mph)
1978 Japan HSST-01 308 km/h (191 mph)
1978 Japan HSST-02 110 km/h (68 mph)
1979 Japan ML-500R 504 km/h (313 mph)
1979 Japan ML-500R 517 km/h (321 mph)
1987 West Germany TR-06 406 km/h (252 mph)
1987 Japan MLU001 401 km/h (249 mph)
1988 West Germany TR-06 413 km/h (257 mph)
1989 West Germany TR-07 436 km/h (271 mph)
1993 Germany TR-07 450 km/h (280 mph)
1994 Japan MLU002N 431 km/h (268 mph)
1997 Japan MLX01 531 km/h (330 mph)
1997 Japan MLX01 550 km/h (340 mph)
1999 Japan MLX01 552 km/h (343 mph)
2003 Japan MLX01 581 km/h (361 mph)
2015 Japan L0 590 km/h (370 mph)
2015 Japan L0 603 km/h (375 mph)
Table SEQ Table * ARABIC 2: History of Maglev speed records
5.0 Comparison with conventional trains
Maglev transport is non-contact and electric powered. It relies less or not at all on the wheels, bearings and axles common to wheeled rail systems.
Speed: Maglev allows higher top speeds than conventional rail, but experimental wheel-based high-speed trains have demonstrated similar speeds.
Maintenance: Maglev trains currently in operation have demonstrated the need for minimal guide way maintenance. Vehicle maintenance is also minimal (based on hours of operation, rather than on speed or distance traveled). Traditional rail is subject to mechanical wear and tear that increases exponentially with speed, also increasing maintenance. For example: the wearing down of brakes and overhead wire wear have caused problems for the Fastech 360 rail Shinkansen. Maglev would eliminate these issues.
Weather: Maglev trains are little affected by snow, ice, severe cold, rain or high winds. However, they have not operated in the wide range of conditions that traditional friction-based rail systems have operated. Maglev vehicles accelerate and decelerate faster than mechanical systems regardless of the slickness of the guideway or the slope of the grade because they are non-contact systems.
Track: Maglev trains are not compatible with conventional track, and therefore require custom infrastructure for their entire route. By contrast conventional high-speed trains such as the TGV are able to run, albeit at reduced speeds, on existing rail infrastructure, thus reducing expenditure where new infrastructure would be particularly expensive (such as the final approaches to city terminals), or on extensions where traffic does not justify new infrastructure. John Harding, former chief maglev scientist at the Federal Railroad Administration, claimed that separate maglev infrastructure more than pays for itself with higher levels of all-weather operational availability and nominal maintenance costs. These claims have yet to be proven in an intense operational setting and they do not consider the increased maglev construction costs.
Efficiency: Conventional rail is probably more efficient at lower speeds. But due to the lack of physical contact between the track and the vehicle, maglev trains experience no rolling resistance, leaving only air resistance and electromagnetic drag, potentially improving power efficiency. Some systems however such as the Central Japan Railway Company SCMaglev use rubber tires at low speeds, reducing efficiency gains.
Weight: The electromagnets in many EMS and EDS designs require between 1 and 2 kilowatts per ton. The use of superconductor magnets can reduce the electromagnets’ energy consumption. A 50-ton Transrapid maglev vehicle can lift an additional 20 tons, for a total of 70 tons, which consumes 70–140 kW (94–188 hp). Most energy use for the TRI is for propulsion and overcoming air resistance at speeds over 100 mph (160 km/h).
Weight loading: High speed rail requires more support and construction for its concentrated wheel loading. Maglev cars are lighter and distribute weight more evenly.
Noise: Because the major source of noise of a maglev train comes from displaced air rather than from wheels touching rails, maglev trains produce less noise than a conventional train at equivalent speeds. However , the psychoacoustic profile of the maglev may reduce this benefit: a study concluded that maglev noise should be rated like road traffic, while conventional trains experience a 5–10 dB “bonus”, as they are found less annoying at the same loudness level.
Magnet reliability: Superconducting magnets are generally used to generate the powerful magnetic fields to levitate and propel the trains. These magnets must be kept below their critical temperatures (this ranges from 4.2 K to 77 K, depending on the material). New alloys and manufacturing techniques in superconductors and cooling systems have helped address this issue.
Control systems: No signalling systems are needed for high-speed rail, because such systems are computer controlled. Human operators cannot react fast enough to manage high-speed trains. High speed systems require Comparison with conventional trains dedicated rights of way and are usually elevated. Two maglev system microwave towers are in constant contact with trains. There is no need for train whistles or horns, either.11
6.0 Comparison with aircraft
Differences between airplane and maglev travel:
Efficiency: For maglev systems the lift-to-drag ratio can exceed that of aircraft (for example Inductrack can approach 200:1 at high speed, far higher than any aircraft). This can make maglev more efficient per kilometer. However, at high cruising speeds, aerodynamic drag is much larger than lift-induced drag. Jets take advantage of low air density at high altitudes to significantly reduce air drag. Hence despite their lift-to-drag ratio disadvantage, they can travel more efficiently at high speeds than maglev trains that operate at sea level.
Routing: Maglevs offer competitive journey times for distances of 800 km (500 mi) or less. Additionally, maglevs can easily serve intermediate destinations.
Availability: Maglevs are little affected by weather.
Travel time: Maglevs do not face the extended security protocols faced by air travelers nor is time consumed for taxiing, or for queuing for take-off and landing.12
7.0 Advantages and Disadvantages of Maglev
Less susceptible to congestion and weather conditions than air or highway.
Maglev trains experience no rolling resistance, leaving only air resistance, potentially improving power efficiency.
Maglev trains produce less noise than a conventional train at equivalent speeds.
Faster trips, High speed, Less time.
Eliminates the need for overhead wires compared to conventional trains.
Average cost is 4 cents per passenger mile as compared to 13 cents per passenger.
Access to Maglev station is much easier than airports.
Maglev schedule will not be disturbed due to bad weather.
Large initial capital investment.
Lack of human experience with Maglev technology.
Although the tracks could be elevated, there would be the addition of guideways crossing great amount of land.
While the Maglev can be safer overall, any infrequent accidents that do occur are likely to be more catastrophic due to the elevated guideways and incredible speeds.
Designing of tracks.
August 11, 2006 fire in Shanghai Transrapid
19621502958465Figure SEQ Figure * ARABIC 23: August 11, 2006 fire in Shanghai Transrapid
Figure SEQ Figure * ARABIC 23: August 11, 2006 fire in Shanghai Transrapid
1962150434340On August 11, 2006 a fire broke out on the Shanghai Transrapid, shortly after leaving the Longyang terminal. This was the first accident on a maglev train in commercial operation. Train operation was shut down immediately. Passengers were able to disembark the train safely and no casualties were reported. Operations resumed on one line after some days.
The fire was thought to have originated below the passenger compartment, possibly as a result of battery malfunction.
Accident of Lathen Transrapid, Germany
The 2006 Lathen Maglev train accident occurred on 22 September 2006 when a Transrapid magnetic levitation (maglev) train collided with a maintenance vehicle near Lathen, Germany. 23 people were killed, making this the first fatal accident on a maglev train.
-381002545080Figure SEQ Figure * ARABIC 24: Accident of Lathen Transrapid, Germany
0Figure SEQ Figure * ARABIC 24: Accident of Lathen Transrapid, Germany
-381001638303298825163830The Miyazaki Fire incident
1905002736850Figure SEQ Figure * ARABIC 25: The Miyazaki Fire incident.
00Figure SEQ Figure * ARABIC 25: The Miyazaki Fire incident.
3105150765175190500732155The MLU002 (Japan) test train was completely consumed in a fire in Miyazaki. As a result, the political opposition claimed maglev was a waste of public money. New designs were made.13
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