2. MAGLEV trains: main characteristics and prospects for operation

3. Flying Express. Domestic and foreign developments

3.1 Development of new modes of transport

3.2 High-speed maglev transport

Conclusion

Bibliography

Introduction

Recently, the famous English science fiction writer Arthur Clark made another prediction. “... We may be on the verge of creating a new type of spacecraft that will be able to leave the Earth at minimal cost by overcoming the gravitational barrier,” he believes. “Then rockets today will be what balloons were before World War I.” On what is such a judgment based? The answer must be sought in the modern ideas of creating transport on a magnetic cushion.

Half a century ago, a magnetic pillow was something out of the realm of fantasy. However, now scientists from many countries are working on the creation of transport on a magnetic cushion. The trains of the future will "hover" above the ground, as if they are "suspended" from the rails, or repelled from them, depending on which system will be used, that is, an electromagnetic or electrodynamic suspension. In the first case, the path is steel rails with a carriage “suspended” to them. In the second case, the composition will go along the metal sheet, in which electric currents arise. Linear motors will be used as a traction mechanism in such trains.

It should be noted that the maglev train began to operate in the eighties of the last century in Birmingham. True, after eleven years of operation, this train was withdrawn from the line due to technical problems. A maglev transport system is currently operating in China, connecting downtown Shanghai with Pudong International Airport. And in Japan, an experimental train on a magnetic cushion MLX01 in 2003 set an absolute speed record for this type of transport, accelerating to 581 km / h.

The purpose of this test is to describe the main characteristics of magnetic levitation transport and further prospects for the use of transport of the future.

The implementation of the goal is achieved by solving the following tasks:

· to give a description of the theoretical prerequisites for the creation of transport on a magnetic cushion;

· give a description of the technical characteristics and prospects for the operation of trains on a magnetic cushion;

· to give a description of the latest domestic and foreign developments of vehicles operating on the basis of the levitation effect.

1. Levitation vs. Gravity: Momentum for maglev vehicles

The literal meaning of the word "levitation" is rise. At least, this is how the British Encyclopedia defines the possibility of raising any body (including a human one) without contact with anything. It entered into technical use relatively recently, in connection with attempts to create a transport on a magnetic cushion.

Its essence can be understood from visual experience, often demonstrated in school. They take two ferrite rings, which are strong permanent magnets, and string them on a glass rod placed vertically. In this case, the upper of the magnets, as it were, hangs in the air. However, once the wand is removed, the magnetic ring will flip over and fall. That's why engineers have to work hard to stabilize the magnetic pad. That is why the magnetic levitation transport, on which they have been working for a quarter of a century, has not gone beyond the polygons.

All the more surprising is the trick demonstrated by the inventor-researcher Alexander Kushelev. On the table, he placed a ceramic magnet from a loudspeaker with a diameter of 80 mm. I carefully adjusted the horizontal position of its position with wooden wedges. He covered the top of the magnet with a plate of plexiglass, on which he spun the top he made himself. And the inexplicable happened: the magnet broke away from the surface of the plexiglass and hung in the air.

After 40 seconds, he slowed down his rotation, lost his balance and somersaulted down. This can be explained as follows: the top is also magnetic, and rotation due to the gyroscopic effect stabilizes its position in the same way as the glass rod mentioned above. When asked if it was possible to build some kind of levitating vehicle on the basis of this effect, Kushelev replied that he was thinking about just this.

In addition, magnetic levitation can, in principle, be realized with the help of superconductivity. If you take a superconductor, pass an electric current through it and place it over a magnet, then it will hang in the air and will hover until the power is turned off. Here, stabilization is carried out as if by itself - any movement of the superconductor causes eddy currents in it, the magnetic fields of which, exactly mirrored in relation to the field of the magnet, drive it back to its original place. Naturally, this is also true for any movement of the magnet (when the superconductor is immobile). A similar method of magnetic suspension has already found application in technology in the creation of ultra-precise gyroscopes for missile and aircraft guidance systems. Moreover, as it turned out quite recently, the use of superconductivity has a unique side effect.

Is it possible to tame gravity? In 1996, physicist John Schnurer of Enioch College in Yellow Spring, Ohio, was convinced of this. When he placed a small piece of plastic attached to a precision scale above an 2.5 cm diameter superconducting disk suspended in the air, it showed a weight reduction of about 5%. At first, Schnurer could not believe his own eyes. He conducted the experiment 12 times before he came to the final conclusion: the phenomenon repeats itself regularly. Then he remembered that back in the early 90s, a similar phenomenon was noticed by our compatriot, a specialist in the field of materials science Evgeny Podkletnov, who at that time worked at the Tampere University of Technology (Finland). But then the observed results were considered an experimental error.

Now they are trying to reproduce similar experiments at the J. Marshall Space Flight Center, NASA and several other US government laboratories. According to Whit Brantley, head of NASA's Advanced Concepts Division, people are so passionate about research that they sometimes spend their own money to buy missing equipment. Theorists also got involved. For example, the Italian Giovanni Modanesi from the National Agency for Nuclear Physics and High Energy Physics believes that in this case we are dealing with the emergence of a "gravitational screen". And a leading specialist at the University of Alabama, Ning Li, believes that under certain conditions, the fields of atoms of a superconductor are able to interact with each other in such an exotic way that levitation occurs.

However, there is another way to create levitation. “One of the directions for further research will be a revision of the nature of gravity - on the basis of electromagnetic and electrostatic phenomena,” believes Vladimir Ponomarev, candidate of technical sciences from the city of Lytkarino near Moscow. Coulomb are outwardly very similar, only in the first expression in the numerator are the masses of interacting bodies, and in the second - their electric charges.

Moreover, upon closer examination, it turns out that the analogies go deeper than the external similarity. According to generally accepted ideas, the phenomenon of gravity is based on the interaction of certain gravity quanta - gravitons; however, so far no one has experimentally discovered either themselves or the gravitational waves emitted by them. But what if gravitons are to some extent identical to elementary electrostatic charges (let's call them pendants)?

This assumption leads to the following reasoning. Since any body in the universe has a temperature above absolute zero, the atoms inside it experience thermal vibrations. And these fluctuations, in accordance with the principles of the electromagnetic theory of Maxwell-Lorentz, inevitably lead to fluctuations of microscopic polarized charges. Summing up, they form a common charge. Thus, gravitational attraction, in principle, can be replaced by electrostatic attraction. Let's say the Earth-Sun system is in equilibrium because the centrifugal force running along its orbit of the Earth is equal to the force of mutual attraction of its opposite electrostatic charges and the Sun. But in the Earth-Moon system, this balance is disturbed. And because of this, the moon is gradually moving away from our planet; however, little by little - only 1.3 cm per year.

The use of the levitation effect based on electromagnetic and electrostatic phenomena opens up broad prospects in practice. Electrostatic fields should be used to create a new type of aircraft, Ponomarev believes. Its movement in the near-Earth space will be determined by the interaction of the planet's electrostatic fields and that created in the working body of the machine.

As long as there are no free electric charges of the required magnitude and sign in the apparatus, it rests on the surface of the planet. But as soon as ions accumulate inside it, obtained by ionizing the gas of the same sign as the planet's electrostatic field, the apparatus will take off. Moreover, according to the calculations of V.I. Ponomarev, it turns out that such a scheme will at least increase the efficiency of aircraft by an order of magnitude compared to current aircraft and missiles. The design of such an aircraft may well be used not only in the study of small planets or asteroids of the solar system, but also in open interstellar space.

Another attempt to tame levitation was made at the end of 1997 by Japanese researchers who work under contract with the international corporation Matsushita. They decided to use an ordinary gyroscope to create a machine that overcomes gravity. Their experiences are captivatingly simple. A small gyroscope is spun up to 18,000 rpm and placed in an airtight container from which the air is pumped out, and it is thrown down. When dropped, the container covers a fixed distance of about 2 m, and the time is measured in the most accurate way using two laser beams. When one (start) crosses, the electronic stopwatch starts, when the other (finish) it stops.

It is also a train on a magnetic cushion, it is also maglev from the English magnetic levitation ("magnetic levitation") - a train on a magnetic suspension, driven and controlled by the force of an electromagnetic field. Such a train, unlike traditional trains, does not touch the rail surface during movement. Since there is a gap between the train and the running surface, friction is eliminated and the only braking force is aerodynamic drag. Maglev refers to monorail transport.

Monorail:

High-speed ground transport (HST) refers to rail transport that allows trains to travel at speeds in excess of 200 km/h (120 mph). Although at the beginning of the 20th century, high-speed trains were called, following at speeds above 150-160 km / h.
Today, VSNT trains move along specially dedicated railway tracks - a high-speed line (HSR), or on a magnetic suspension, along which the maglev shown above moves.

The first regular movement of high-speed trains began in 1964 in Japan. In 1981, HCNT trains began to run in France, and soon most of Western Europe, including the UK, was united into a single high-speed rail network. Modern high-speed trains in operation develop speeds of about 350-400 km / h, and in tests they can even accelerate to 560-580 km / h, such as the JR-Maglev MLX01, which set a speed record during tests in 2003 - 581 km / h h.
In Russia, the regular operation of high-speed trains, on common tracks with conventional trains, began in 2009. And only by 2017 is expected to complete the construction of Russia's first specialized high-speed railway line Moscow - St. Petersburg.

In addition to passengers, high-speed trains also carry goods, for example: the French service La Poste has a fleet of special TGV electric trains for the transport of mail and parcels.

The speed of "magnetic" trains, that is, maglevs, is comparable to the speed of an airplane and allows it to compete with air transport in short- and medium-haul directions (up to 1000 km). Although the idea of ​​such transport is not new, economic and technical constraints have not allowed it to unfold in full.

At the moment, there are 3 main technologies for magnetic suspension of trains:

1. On superconducting magnets (electrodynamic suspension, EDS);
2. On electromagnets (electromagnetic suspension, EMS);
3. On permanent magnets; it is the new and potentially most economical system.

The composition levitates due to the repulsion of identical magnetic poles and, conversely, the attraction of opposite poles. Propulsion is carried out by a linear motor, located either on the train or on the track, or both. A serious design problem is the large weight of sufficiently powerful magnets, since a strong magnetic field is required to maintain a massive composition in the air.

Advantages of Maglev:

• theoretically the highest speed that can be obtained on public (non-sports) land transport;
• great prospects for achieving speeds many times higher than those used in jet aviation;
• low noise.

Maglev Disadvantages:

• high cost of creating and maintaining a track - the cost of building one kilometer of a maglev track is comparable to driving a kilometer of a metro tunnel in a closed way;
• the generated electromagnetic field may be harmful to train crews and nearby residents. Even the traction transformers used on AC electrified railways are harmful to drivers. But in this case, the field strength is an order of magnitude higher. It is also possible that maglev lines will not be available to people using pacemakers;
• standard-width rail tracks rebuilt for high-speed traffic remain accessible to regular passenger and suburban trains. The high-speed maglev track is not suitable for anything else; additional paths for low-speed communication will be required.

The most active developments of maglev are carried out by Germany and Japan.

*Help: What is a shinkansen?
Shinkansen is the name of the high-speed rail network in Japan, designed to transport passengers between major cities in the country. Owned by Japan Railways. The first line was opened between Osaka and Tokyo in 1964 - Tokaido Shinkansen. This line is the world's busiest high-speed rail line. It carries about 375,000 passengers daily.

"Bullet train" is one of the names for shinkansen trains. Trains can have up to 16 cars. Each wagon reaches a length of 25 meters, with the exception of the head wagons, which are usually slightly longer. The total length of the train is about 400 meters. Stations for such trains are also very long and specially adapted for these trains.

In Japan, maglevs are often referred to as "rinia:ka:" (Japanese: リニアカー), derived from the English "linear car" due to the linear motor used on board.

JR-Maglev uses electrodynamic suspension with superconducting magnets (EDS) installed both on the train and on the track. Unlike the German Transrapid system, JR-Maglev does not use a monorail layout: trains run in a channel between magnets. This scheme allows you to develop higher speeds, provides greater safety for passengers in the event of an evacuation and ease of operation.

Unlike electromagnetic suspension (EMS), trains built using EDS technology require additional wheels when driving at low speeds (up to 150 km/h). When a certain speed is reached, the wheels are separated from the ground and the train "flies" at a distance of several centimeters from the surface. In the event of an accident, the wheels also allow for a smoother stop of the train.

For normal braking, electrodynamic brakes are used. For emergencies, the train is equipped with retractable aerodynamic and disc brakes on the bogies.

Driving in a maglev with a maximum speed of 501 km/h. The description states that the video was made in 2005:

On the Yamanashi line, several trains are being tested with different nose cone shapes, from the usual pointed nose cone to an almost flat one, 14 meters long, designed to get rid of the loud bang that accompanies the train entering the tunnel at high speed. The maglev train can be fully computer controlled. The driver controls the operation of the computer and receives an image of the path through the video camera (the driver's cab does not have front view windows).

The JR-Maglev technology is more expensive than the similar Transrapid development implemented in China (the line to the Shanghai airport), as it requires high costs for equipping the route with superconducting magnets and explosive tunneling in the mountains. The total cost of the project may reach 82.5 billion US dollars. If the line is laid along the Tokaido Coastal Highway, it will cost less, but will require the construction of a large number of short tunnels. Despite the fact that the maglev train itself is silent, each entry into the tunnel at high speed will cause a pop, comparable in volume to an explosion, so laying a line in densely populated areas is impossible.

Sukhov Vitaly Vladimirovich, Galin Alexey Leonidovich

We present to you a project whose main theme is "Electromagnetic Vehicles and Apparatus". Having taken up this work, we realized that the most interesting issue for us is the transport on a magnetic cushion.

Recently, the famous English science fiction writer Arthur Clark made another prediction. “... We may be on the verge of creating a new type of spacecraft that will be able to leave the Earth at minimal cost by overcoming the gravitational barrier,” he believes. “Then rockets today will be what balloons were before World War I.” On what is such a judgment based? The answer must be sought in the modern ideas of creating transport on a magnetic cushion.

Download:

Preview:

I-st open student scientific and practical conference

"My project activity in college"

Direction of the scientific and practical project:

electrical engineering

Project theme:

Electromagnetic vehicles and apparatuses. Maglev transport

Project prepared:

Sukhov Vitaly Vladimirovich, student of group 2 ET

Galin Alexey Leonidovich, student of group 2 ET

The name of the institution:

GBOU SPO Electromechanical College №55

Project Manager:

Utenkova Eaterina Sergeevna

Moscow 2012

Introduction

Maglev or Maglev

Halbach installation

Conclusion

Bibliography

Introduction

We present to you a project whose main theme is "Electromagnetic Vehicles and Apparatus". Having taken up this work, we realized that the most interesting issue for us is the transport on a magnetic cushion.

Recently, the famous English science fiction writer Arthur Clark made another prediction. “... We may be on the verge of creating a new type of spacecraft that will be able to leave the Earth at minimal cost by overcoming the gravitational barrier,” he believes. “Then rockets today will be what balloons were before World War I.” On what is such a judgment based? The answer must be sought in the modern ideas of creating transport on a magnetic cushion.

Maglev or Maglev

Maglev or Maglev (from the English magnetic levitation) is a train on a magnetic suspension, driven and controlled by magnetic forces. Such a train, unlike traditional trains, does not touch the rail surface during movement. Since there is a gap between the train and the running surface, friction is eliminated and the only braking force is the drag force.

The speed achievable by a maglev is comparable to the speed of an aircraft and makes it possible to compete with air communications at short (for aviation) distances (up to 1000 km). Although the very idea of ​​such transport is not new, economic and technical limitations did not allow it to be fully deployed: the technology was implemented for public use only a few times. Currently, Maglev cannot use the existing transport infrastructure, although there are projects with the location of magnetic road elements between the rails of a conventional railway or under the roadbed.

The need for magnetic levitation trains (MAGLEV) has been discussed for many years, but the results of attempts to actually use them have been discouraging. The most important drawback of MAGLEV trains lies in the peculiarities of the operation of electromagnets, which ensure the levitation of the cars above the track. Electromagnets that are not cooled to the state of superconductivity consume gigantic amounts of energy. When using superconductors in the web, the cost of cooling them will negate all economic advantages and the possibility of implementing the project.

An alternative is proposed by physicist Richard Post of Lawrence Livermore National Laboratory, California. Its essence is to use not electromagnets, but permanent magnets. Previously used permanent magnets were too weak to lift a train, and Post uses a partial acceleration method developed by retired physicist Klaus Halbach of Lawrence Berkley National Laboratory. Halbach proposed a method for arranging permanent magnets in such a way as to concentrate their total fields in one direction. Inductrack, as Post called the system, uses Halbach units built into the bottom of the car. The web itself is an ordered arrangement of coils of insulated copper cable.

Halbach installation

The Halbach installation concentrates the magnetic field at a certain point, reducing it at others. Being installed in the bottom of the car, it generates a magnetic field that induces sufficient currents in the windings of the canvas under the moving car to lift the car a few centimeters and stabilize it [fig.1]. When the train stops, the levitation effect disappears, the cars are lowered onto additional chassis.

Rice. 1 Halbach installation

The figure shows a 20 meter MAGLEV test track for Inductrack type trains, which contains about 1000 rectangular inductive coils, each 15 cm wide. In the foreground is the test trolley and the electrical circuit. Aluminum rails along the canvas support the trolley until stable levitation is achieved. Halbach installations provide: under the bottom - levitation, on the sides - stability.

When the train reaches a speed of 1-2 km / h, the magnets produce enough currents in the inductive windings to levitate the train. The force driving the train is generated by electromagnets placed at intervals along the track. The fields of the electromagnets pulsate in such a way that they repel the Halbach installations mounted on the train and move it forward. According to Post, with the correct arrangement of the Halbach installations, the cars will not lose their balance under any circumstances, up to an earthquake. Now, based on the success of Post's 1/20 scale demonstration work, NASA has signed a 3-year contract with his team at Livermore to further explore this concept for more efficient launching of satellites into orbit. It is assumed that this system will be used as a reusable booster that would accelerate the rocket to a speed of about Mach 1, before turning on the main engines on it.

However, despite all the difficulties, the prospects for using magnetic levitation vehicles remain very attractive. Thus, the Japanese government is preparing to resume work on a fundamentally new type of land transport - trains on a magnetic cushion. According to the assurances of the engineers, the maglev cars are capable of covering the distance between the two largest populated centers of Japan - Tokyo and Osaka - in just 1 hour. The current high-speed rail express takes 2.5 times more time to do this.

The secret of Maglev's speed is that the cars suspended in the air by the force of electromagnetic repulsion do not move along the track, but above it. This completely eliminates the losses that are inevitable when the wheels rub against the rails. Long-term testing, conducted in Yamanashi Prefecture on a trial section 18.4 km long, confirmed the reliability and safety of this transportation system. The cars, moving in automatic mode, without a passenger load, developed a speed of 550 km / h. So far, the record for high-speed travel on rails belongs to the French, whose TGV train in 1990 accelerated to 515 km / h during tests.

Issues of operation of vehicles on a magnetic cushion

The Japanese are also concerned about economic problems, and first of all, the question of the profitability of the high-speed maglev line. Today, about 24 million people travel between Tokyo and Osaka every year, 70% of passengers use the high-speed railway line. According to futurologists, the revolutionary development of the computer communication network will inevitably lead to a decrease in passenger traffic between the two largest centers of the country. The planned decline in the active population of the country may also affect the congestion of transport lines.

The Russian project of opening the movement of trains on a magnetic cushion from Moscow to St. Petersburg in the near future will not be implemented, Mikhail Akulov, head of the Federal Agency for Railway Transport, said at a press conference in Moscow at the end of February 2011. There may be problems with this project, since there is no experience of operating maglev trains in winter conditions, Akulov said, saying that such a project was proposed by a group of Russian developers who adopted the experience of China. At the same time, Akulov noted that the idea of ​​creating a high-speed highway Moscow - St. Petersburg is again relevant today. In particular, it was proposed to combine the creation of a high-speed highway with the parallel construction of an automobile highway. The head of the agency added that powerful business structures from Asia are ready to participate in this project, without specifying which structures he is talking about.

Train Magnetic Suspension Technologies

At the moment, there are 3 main technologies for magnetic suspension of trains:

1. On superconducting magnets (electrodynamic suspension, EDS).

Superconducting magnet - a solenoid or electromagnet with a winding made of a superconducting material. The winding in the state of superconductivity has zero ohmic resistance. If such a winding is short-circuited, then the electric current induced in it remains almost arbitrarily long.

The magnetic field of a continuous current circulating through the winding of a superconducting magnet is exceptionally stable and ripple-free, which is important for a number of applications in scientific research and engineering. The winding of a superconducting magnet loses the property of superconductivity when the temperature rises above the critical temperature Tk of the superconductor, when the critical current Ik or the critical magnetic field Hk is reached in the winding. Given this, for the windings of superconducting magnets. materials with high values ​​of Tk, Ik and Hk are used.

2. On electromagnets (electromagnetic suspension, EMS).

3. On permanent magnets; it is the new and potentially most economical system.

The composition levitates due to the repulsion of the same poles of the magnets and, conversely, the attraction of different poles. The movement is carried out by a linear motor.

A linear motor is an electric motor in which one of the elements of the magnetic system is open and has a deployed winding that creates a traveling magnetic field, and the other is made in the form of a guide that provides linear movement of the moving part of the motor.

Now there are many designs of linear motors, but all of them can be divided into two categories - low acceleration motors and high acceleration motors.

Low acceleration engines are used in public transport (maglev, monorail, subway). High acceleration thrusters are quite small in length and are typically used to accelerate an object to high speed and then release it. They are often used for hypervelocity collision research, as weapons or spacecraft launchers. Linear motors are also widely used in machine tool feed drives and in robotics. located either on the train, or on the way, or both there and there. A serious design problem is the large weight of sufficiently powerful magnets, since a strong magnetic field is required to maintain a massive composition in the air.

According to the Earnshaw theorem (S. Earnshaw, sometimes written by Earnshaw), static fields created by electromagnets and permanent magnets alone are unstable, unlike the fields of diamagnets.

Diamagnets are substances that are magnetized towards the direction of the external magnetic field acting on them. In the absence of an external magnetic field, diamagnets have no magnetic moment. and superconducting magnets. There are stabilization systems: sensors constantly measure the distance from the train to the track and, accordingly, the voltage on the electromagnets changes.

You can consider the principle of movement of vehicles on a magnetic cushion in the following diagram.

It shows the principle of moving vehicles forward, under the influence of changing magnetic fields. The location of the magnets makes it possible for the car to seem to be pulled forward towards the opposite pole, thereby moving the entire structure.

The most detailed Sami magnetic installation is shown in the diagram.designs of magnetic suspension and electric drive of the vehicle based on linear asynchronous machines

Rice. 1. The design of the magnetic suspension and electric drive of the vehicle based on linear asynchronous machines:
1 - magnetic suspension inductor; 2 - secondary element; 3 - cover; 4.5 - teeth and winding of the suspension inductor; 6.7 - conductive cage and magnetic circuit of the secondary element; 8 - base; 9-platform; 10 - crew body; 11, 12 - springs; 13 - damper; 14 - rod; 15 - cylindrical hinge; 16 - sliding support; 17 - bracket; 18 - emphasis; 19 - rod. Von - magnetic field speed: Fn - lifting force of the suspension: Wb - induction of the working gap of the suspension

Fig.2. The design of the traction linear asynchronous motor:
1 - traction drive inductor; 2 - secondary element; 3 - magnetic circuit of the drive inductor; 4 - pressure plates of the drive inductor; 5 - teeth of the drive inductor; 6 - winding coils of the drive inductor; 7 - base.

Advantages and disadvantages of magnetic levitation transport

Advantages

• Theoretically the highest speed that can be obtained on a serial (non-sport) land transport.
• Low noise.

disadvantages

• The high cost of creating and maintaining a track.
• Weight of magnets, power consumption.
• The electromagnetic field created by the magnetic suspension can be harmful to train crews and/or nearby residents. Even traction transformers used on AC electrified railways are harmful to drivers, but in this case the field strength is an order of magnitude greater. It is also possible that maglev lines will not be available to people using pacemakers.
• It will be required at high speed (hundreds of km / h) to control the gap between the road and the train (several centimeters). This requires ultra-fast control systems.
• A complex track infrastructure is required.

For example, a maglev arrow represents two sections of the road that replace each other depending on the direction of the turn. Therefore, it is unlikely that maglev lines will form more or less branched networks with forks and intersections.

Development of new types of transport

Work on the creation of high-speed wheelless trains on a magnetic cushion has been going on for a long time, in particular in the Soviet Union since 1974. However, until now the problem of the most promising transport of the future remains open and is a wide field of activity for.

Rice. 2 Magnetic levitation train model

Figure 2 shows a model of a maglev train, where the developers decided to turn the entire mechanical system upside down. The railway track is a set of reinforced concrete supports spaced at certain equal distances with special openings (windows) for trains. There are no rails. Why? The fact is that the model is turned upside down, and the train itself serves as a rail, and wheels with electric motors are installed in the windows of the supports, the rotation speed of which is remotely controlled by the train driver. Thus, the train, as it were, flies through the air. The distances between the supports are selected in such a way that at each moment of its movement the train is in at least two or three of them, and one car has a length greater than one span. This allows not only to keep the train on weight, but, at the same time, if one of the wheels fails in any support, the movement will continue.

The advantages of using this particular model are enough. Firstly, it saves on materials, secondly, the weight of the train is significantly reduced (neither engines nor wheels are needed), thirdly, such a model is extremely environmentally friendly, and fourthly, to lay such a route in a densely populated city or area with uneven terrain is much easier than in standard modes of transport.

But we can not say about the shortcomings. For example, if one of the supports deviates strongly within the route, this will lead to disaster. Although, catastrophes are possible within the framework of conventional railways. Another issue that leads to a strong rise in the cost of technology is the physical load on the supports. For example, the tail of a train that has just left a particular opening, in simple words, “hangs” and exerts a large load on the next support, while the center of gravity of the train itself also shifts, which affects all supports as a whole. Approximately the same situation occurs when the head of the train leaves the opening and "hangs" in the same way until it reaches the next support. It turns out a kind of swing. How the designers intend to solve this problem (with the help of a carrier wing, great speed, reducing the distance between the supports ...) is still unclear. But there are solutions. And the third problem is turns. Since the developers decided that the length of the car is more than one span, there is a question of turns

Rice. 3 Yunitskiy's High-Speed ​​String Transport

As an alternative to this, there is a purely Russian development called Yunitskiy's High-Speed ​​String Transport (STU). Within its framework, it is proposed to use prestressed string-rails raised on supports to a height of 5-25 meters, along which four-wheeled transport modules move. The cost price of UST turns out to be much lower - $600-800 thousand per kilometer, and with infrastructure and rolling stock - $900-1200 thousand per km.

Rice. 4 Example of monorail transport

But the near future is still seen for the usual monorail performance. Moreover, within the framework of monorail systems, the latest technologies for automating transport are now being rolled back. For example, the American corporation Taxi 2000 creates a monorail system of automatic taxis SkyWeb Express, which can travel both within the city and beyond. A driver is not needed in such taxis (just like in science fiction books and films). You indicate the destination, and the taxi itself takes you there, independently building the best route. Everything is obtained here - both safety and accuracy. Taxi 2000 is currently the most realistic and feasible project

Conclusion

Magnetic levitation trains are considered one of the most promising modes of transport of the future. Magnetic levitation trains differ from ordinary trains and monorails by the complete absence of wheels - when moving, the cars seem to hover over one wide rail due to the action of magnetic forces. As a result, the speed of such a train can reach 400 km/h, and in some cases such transport can replace an airplane. Currently, there is only one magnetic road project in practice in the world, also called Transrapid.

Many developments and projects are already 20-30 years old. And the main task for their creators is to attract investors. The problem of transport itself is quite significant, because often we buy some products so expensive, because a lot has been spent on their transportation. The second problem is the environment, the third one is the heavy congestion of transport routes, which increases from year to year, and for some types of transport by tens of percent.

Let's hope that in the near future we ourselves will be able to ride on vehicles with a magnetic cushion. Time is moving...

Bibliography

1. Drozdova T.E. Theoretical foundations of progressive technologies. - Moscow: MGOU, 2001. - 212 p.
2. Materials science and technology of structural materials / Tyalina L.N., Fedorova N.V. Tutorial. - Tambov: TSTU, 2006. - 457 p.
3. Methods for protecting internal waters from pollution and exhaustion / ed. Gavich I.K. - M.: UNITI-DANA, 2002. - 287 p.
4. Methods of industrial wastewater treatment / Zhukov A.I. Mongait I.L., Rodziller I.D. - M.: Infra-M, 2005. - 338 p.
5. Fundamentals of technology of the most important industries / ed. Sidorova I.A. Textbook of universities. - M.: Higher School, 2003. - 396 p.
6. The system of technologies of the most important branches of the national economy / Dvortsin M.D., Dmitrienko V.V., Krutikova L.V., Mashikhina L.G. Tutorial. - Khabarovsk: KhPI, 2003. - 523 p.

Zoom-presentation:http://zoom.pspu.ru/presentations/145

1. Appointment

maglev train or maglev(from the English magnetic levitation, i.e. "maglev" - magnetic plane) is a train on a magnetic suspension, driven and controlled by magnetic forces, designed to transport people (Fig. 1). Relate to passenger transport technology. Unlike traditional trains, it does not touch the rail surface while running.

2. Main parts (device) and their purpose

There are different technological solutions in the development of this design (see paragraph 6). Consider the principle of operation of the magnetic cushion of the train "Transrapid" on electromagnets ( electromagnetic suspension, EMS) (Fig. 2).

Electronically controlled electromagnets (1) are attached to the metal "skirt" of each car. They interact with the magnets on the underside of the special rail (2), causing the train to hover over the rail. Other magnets provide lateral alignment. A winding (3) is laid along the track, which creates a magnetic field that sets the train in motion (linear motor).

3. Operating principle

The principle of operation of a train on a magnetic suspension is based on the following physical phenomena and laws:

phenomenon and law of electromagnetic induction by M. Faraday

Lenz's rule

Biot-Savart-Laplace law

In 1831, the English physicist Michael Faraday discovered law of electromagnetic induction, Whereby a change in the magnetic flux inside a conducting circuit excites an electric current in this circuit even if there is no power source in the circuit. The question of the direction of the induction current, left open by Faraday, was soon solved by the Russian physicist Emil Khristianovich Lenz.

Consider a closed circular current-carrying circuit without a connected battery or other power source, into which a magnet is introduced with the north pole. This will increase the magnetic flux passing through the circuit, and, according to Faraday's law, an induced current will appear in the circuit. This current, in turn, according to the Biot-Savart law, will generate a magnetic field, the properties of which are no different from the properties of the field of an ordinary magnet with north and south poles. Lenz just managed to find out that the induced current will be directed in such a way that the north pole of the magnetic field generated by the current will be oriented towards the north pole of the inserted magnet. Since there are forces of mutual repulsion between the two north poles of the magnets, the inductive current induced in the circuit will flow in this direction, which will counteract the introduction of the magnet into the circuit. And this is only a special case, and in a generalized formulation, Lenz's rule says that the induction current is always directed in such a way as to counteract the root cause that caused it.

Lenz's rule today is just used in the train on a magnetic cushion. Under the bottom of the car of such a train, powerful magnets are mounted, located a few centimeters from the steel sheet (Fig. 3). When the train moves, the magnetic flux passing through the contour of the canvas is constantly changing, and strong induction currents arise in it, creating a powerful magnetic field that repels the magnetic suspension of the train (similar to how repulsive forces arise between the circuit and the magnet in the above experiment). This force is so great that, having gained some speed, the train literally breaks away from the canvas by several centimeters and, in fact, flies through the air.

The composition levitates due to the repulsion of the same poles of the magnets and, conversely, the attraction of different poles. The creators of the train "Transrapid" (Fig. 1) applied an unexpected magnetic suspension scheme. They did not use the repulsion of like-named poles, but the attraction of opposite-named ones. Hanging a load over a magnet is not difficult (this system is stable), but under a magnet it is almost impossible. But if we take a controlled electromagnet, the situation changes. The control system keeps the gap between the magnets constant at a few millimeters (Fig. 3). With an increase in the gap, the system increases the current strength in the carrier magnets and thus “pulls up” the car; when decreasing, it lowers the current strength, and the gap increases. The scheme has two major advantages. Track magnetic elements are protected from weather influences, and their field is much weaker due to the small gap between the track and the train; it requires much smaller currents. Consequently, a train of this design turns out to be much more economical.

The train moves forward linear motor. Such an engine has a rotor and a stator stretched into strips (in a conventional electric motor they are folded into rings). The stator windings are turned on one by one, creating a traveling magnetic field. The stator, mounted on the locomotive, is drawn into this field and moves the entire train (Fig. 4, 5). . The key element of the technology is the change of poles on electromagnets by alternating supply and removal of current at a frequency of 4000 times per second. The gap between the stator and the rotor to obtain reliable operation should not exceed five millimeters. This is difficult to achieve due to the swaying of cars during movement, which is characteristic of all types of monorails, except for roads with a side suspension, especially when cornering. Therefore, an ideal track infrastructure is needed.

The stability of the system is ensured by automatic regulation of the current in the magnetization windings: the sensors constantly measure the distance from the train to the track and, accordingly, the voltage on the electromagnets changes (Fig. 3). Ultra-fast control systems control the gap between the road and the train.

The only braking force is the aerodynamic drag force.

So, the scheme of the movement of a train on a magnetic suspension: carrying electromagnets are installed under the car, and coils of a linear electric motor are installed on the rail. When they interact, a force arises that lifts the car above the road and pulls it forward. The direction of the current in the windings changes continuously, switching the magnetic fields as the train moves.

Carrier magnets are powered by on-board batteries (Fig. 4), which are recharged at each station. The current to the linear electric motor, which accelerates the train to airplane speeds, is supplied only in the section along which the train goes (Fig. 6 a). A sufficiently strong magnetic field of the composition will induce current in the track windings, and those, in turn, will create a magnetic field.

Where the train speeds up or goes uphill, energy is supplied with more power. If you need to slow down or drive in the opposite direction, the magnetic field changes the vector.

Check out the videos " Law of electromagnetic induction», « Electromagnetic induction» « Faraday's experiments».

Rice. 6. b Frames from the video clips "Law of electromagnetic induction", "Electromagnetic induction", "Experiments of Faraday".

More than two hundred years have passed since the moment when mankind invented the first steam locomotives. However, until now, railway land transport, carrying passengers and using the power of electricity and diesel fuel, is quite common.

It is worth saying that all these years, engineers and inventors have been actively working to create alternative ways of moving. The result of their work was trains on magnetic cushions.

History of appearance

The very idea of ​​creating trains on magnetic cushions was actively developed at the beginning of the twentieth century. However, it was not possible to realize this project at that time for a number of reasons. The manufacture of such a train began only in 1969. It was then that a magnetic track was laid on the territory of the Federal Republic of Germany, along which a new vehicle was to pass, which was later called the maglev train. It was launched in 1971. The first maglev train, which was called Transrapid-02, passed along the magnetic track.

An interesting fact is that German engineers made an alternative vehicle based on the records left by the scientist Hermann Kemper, who received a patent back in 1934, confirming the invention of the magnetic plane.

"Transrapid-02" can hardly be called very fast. He could move at a maximum speed of 90 kilometers per hour. Its capacity was also low - only four people.

In 1979, a more advanced maglev model was created. bearing the name "Transrapid-05", could already carry sixty-eight passengers. He moved along the line located in the city of Hamburg, the length of which was 908 meters. which this train developed was equal to seventy-five kilometers per hour.

In the same 1979, another maglev model was released in Japan. She was called "ML-500". on a magnetic cushion developed a speed of up to five hundred and seventeen kilometers per hour.

Competitiveness

The speed that trains on magnetic cushions can develop can be compared with. In this regard, this type of transport can become a serious competitor to those air routes that operate at a distance of up to a thousand kilometers. The widespread use of maglevs is hindered by the fact that they cannot move on traditional railway surfaces. Trains on magnetic cushions need to build special highways. And this requires a large investment of capital. It is also believed that what is created for maglevs can negatively affect the human body, which will adversely affect the health of the driver and residents of regions located near such a route.

Principle of operation

Trains on magnetic cushions are a special kind of transport. During movement, the maglev seems to hover over the railroad tracks without touching it. This is due to the fact that the vehicle is controlled by the force of an artificially created magnetic field. During the movement of the maglev, there is no friction. The braking force is aerodynamic drag.

How does it work? Each of us knows about the basic properties of magnets from sixth grade physics lessons. If two magnets are brought together with their north poles, they will repel each other. A so-called magnetic cushion is created. When connecting different poles, the magnets will be attracted to each other. This rather simple principle underlies the movement of a maglev train, which literally glides through the air at an insignificant distance from the rails.

At present, two technologies have already been developed, with the help of which a magnetic cushion or suspension is activated. The third is experimental and exists only on paper.

Electromagnetic suspension

This technology is called EMS. It is based on the strength of the electromagnetic field, which changes over time. It causes levitation (rise in the air) of the maglev. For the movement of the train in this case, T-shaped rails are required, which are made of a conductor (usually metal). In this way, the operation of the system is similar to a conventional railway. However, in the train, instead of wheel pairs, support and guide magnets are installed. They are placed parallel to the ferromagnetic stators located along the edge of the T-shaped web.

The main disadvantage of EMS technology is the need to control the distance between the stator and the magnets. And this despite the fact that it depends on many factors, including the unstable nature. In order to avoid a sudden stop of the train, special batteries are installed on it. They are able to recharge the magnets built into the support magnets, and thus maintain the levitation process for a long time.

Braking of trains based on EMS technology is carried out by a low-acceleration synchronous linear motor. It is represented by supporting magnets, as well as the roadway, over which the maglev hovers. The speed and thrust of the composition can be controlled by changing the frequency and strength of the generated alternating current. To slow down, it is enough to change the direction of the magnetic waves.

Electrodynamic suspension

There is a technology in which the movement of the maglev occurs when two fields interact. One of them is created in the highway canvas, and the second - on board the train. This technology is called EDS. On its basis, a Japanese JR-Maglev maglev train was built.

Such a system has some differences from EMS, which uses ordinary magnets, to which electric current is supplied from the coils only when power is applied.

EDS technology implies a constant supply of electricity. This occurs even if the power supply is turned off. Cryogenic cooling is installed in the coils of such a system, which saves significant amounts of electricity.

Advantages and disadvantages of EDS technology

The positive side of a system operating on an electrodynamic suspension is its stability. Even a slight reduction or increase in the distance between the magnets and the canvas is regulated by the forces of repulsion and attraction. This allows the system to be in an unaltered state. With this technology, there is no need to install control electronics. Devices for adjusting the distance between the canvas and the magnets are not needed either.

EDS technology has some disadvantages. Thus, the force sufficient to levitate the composition can only arise at high speed. That is why maglevs are equipped with wheels. They provide their movement at speeds up to one hundred kilometers per hour. Another disadvantage of this technology is the frictional force that occurs in the back and front of the repulsive magnets at a low speed.

Due to the strong magnetic field in the section intended for passengers, it is necessary to install special protection. Otherwise, a person with a pacemaker is not allowed to travel. Protection is also needed for magnetic storage media (credit cards and HDD).

Technology under development

The third system, which currently exists only on paper, is the use of permanent magnets in the EDS version, which do not require an energy supply to activate. Until recently, it was believed that this was impossible. The researchers believed that permanent magnets did not have such a force that could cause the train to levitate. However, this problem was avoided. To solve it, the magnets were placed in the Halbach array. Such an arrangement leads to the creation of a magnetic field not under the array, but above it. This helps to maintain the levitation of the composition even at a speed of about five kilometers per hour.

This project has not yet received practical implementation. This is due to the high cost of arrays made of permanent magnets.

Advantages of maglevs

The most attractive side of maglev trains is the prospect of achieving high speeds that will allow maglevs to compete even with jet aircraft in the future. This type of transport is quite economical in terms of electricity consumption. The costs for its operation are also low. This becomes possible due to the absence of friction. The low noise of maglevs is also pleasing, which will positively affect the environmental situation.

disadvantages

The negative side of maglevs is the too large amount required to create them. Expenses for track maintenance are also high. In addition, the considered mode of transport requires a complex system of tracks and ultra-precise instruments that control the distance between the track and the magnets.

in Berlin

In the capital of Germany in 1980, the opening of the first maglev type system called the M-Bahn took place. The length of the canvas was 1.6 km. A maglev train ran between three metro stations on weekends. Travel for passengers was free. Since then, the city's population has almost doubled. It required the creation of transport networks with the ability to provide high passenger traffic. That is why in 1991 the magnetic canvas was dismantled, and the construction of the metro began in its place.

Birmingham

In this German city, a low-speed maglev connected from 1984 to 1995. airport and railway station. The length of the magnetic path was only 600 m.

Shanghai

The first magnetic road in Berlin was built by the German company Transrapid. The failure of the project did not deter the developers. They continued their research and received an order from the Chinese government, which decided to build a maglev track in the country. Shanghai and Pudong Airport were connected by this high-speed (up to 450 km/h) route.
The 30 km long road was opened in 2002. Future plans include its extension to 175 km.

Japan

In this country in 2005 the exhibition Expo-2005 was held. By its opening, a magnetic track 9 km long was put into operation. There are nine stations on the line. Maglev serves the area adjacent to the exhibition venue.

Maglevs are considered the transport of the future. Already in 2025, it is planned to open a new superhighway in a country like Japan. The maglev train will carry passengers from Tokyo to one of the districts of the central part of the island. Its speed will be 500 km/h. About forty-five billion dollars will be needed to implement the project.

Russia

The creation of a high-speed train is also planned by Russian Railways. By 2030, maglev in Russia will connect Moscow and Vladivostok. Passengers will overcome the path of 9300 km in 20 hours. The speed of the train on a magnetic cushion will reach up to five hundred kilometers per hour.