Despite the fact that more than two hundred years have passed since the creation of the first steam locomotives, humanity is still not ready to completely abandon the use of diesel fuel, steam power and electricity as a driving force capable of moving heavy loads and passengers.

However, as you understand, all this time the engineers-inventors were not in complete inactivity, and the result of the work of their thought was the publication of alternative methods of transportation along the railroad tracks.

The history of the emergence of trains on an electromagnetic cushion

The very idea of ​​making a train moving on a magnetic cushion is not so new. For the first time, the inventors began to think about the creation of such rolling stock at the very beginning of the 20th century, however, for a number of reasons, the implementation of this project could not be carried out for quite a long time.

Only by 1969, on the territory of the then FRG, they began to manufacture a similar train, later called the maglev, and lay the magnetic track. The launch of the first maglev called "Transrapid-02" was made two years later.

An interesting fact is that in the manufacture of the maglev, German engineers relied on the records made by the scientist Hermann Kemper, who received a patent for the creation of a magnetic plane back in 1934. The first maglev "Tranrapid-02" cannot be called high-speed, since it developed a speed of only up to 90 km / h. Its capacity was also very low: only four people.

The next maglev model, created in 1979, "Transrapid-05" already accommodated up to 68 passengers and moved along the passenger line of the city of Hamburg, which has a length of 908 m, at a speed of 75 km / h.

Transrapid-05

At the same time, on the other side of the continent, in Japan, in the same 1979, the ML-500 model maglev was launched, capable of speeds up to 517 km / h.

What is a maglev and how does it work?

A maglev (or simply a maglev train) is a type of transport controlled and driven by the force of a magnetic field. At the same time, the maglev does not touch the railway track, but “levitates” above it, held by an artificially created magnetic field. In this case, friction is excluded, only aerodynamic resistance acts as a braking force.

On short-haul routes in the future, maglev can seriously compete with air transport due to its ability to develop a very high speed of movement. To date, the widespread introduction of maglevs is largely hindered by the fact that they cannot be used on a traditional main railway surface. Maglev can move only on a specially built magnetic line, which requires very large investments.

It is also believed that magnetic transport can negatively affect the body of drivers and residents of regions close to magnetic routes.

Advantages of maglevs

The advantages of maglevs include the vast prospect of achieving high speeds that can compete even with jet aircraft. In addition, maglev is quite economical in terms of electricity consumption by transport. In addition, there is practically no friction of the parts, which can significantly reduce the level of operating costs.

The first maglev train carried a group of passengers as part of the 1979 IVA International Transport Exhibition in Germany. But few people know that in the same year, another maglev, the Soviet model TP-01, drove its first meters along the test track. It is especially surprising that Soviet maglevs have survived to this day - they have been gathering dust in the backyards of history for more than 30 years.

Tim Skorenko

Experiments with vehicles operating on the principle of magnetic levitation began even before the war. In different years and in different countries, operating prototypes of levitating trains appeared. In 1979, the Germans introduced a system that transported more than 50,000 passengers in three months of operation, and in 1984, the first ever permanent line for maglev trains appeared at the international airport in Birmingham (UK). The initial length of the track was 600 m, and the levitation height did not exceed 15 mm. The system operated quite successfully for 11 years, but then technical failures became more frequent due to aging equipment. And because the system was unique, virtually every part had to be custom-made, and the decision was made to shut down the line, which had been a total loss.

1986, TP-05 at the Ramenskoye training ground. The 800-meter section did not allow accelerating to cruising speeds, but the initial “races” did not require this. The car, built in an extremely short time, managed almost without "childhood illnesses", and this was a good result.

In addition to the British, mass-produced magnetic trains were quite successfully launched by everyone in the same Germany - the Transrapid company operated a similar system 31.5 km long in the Emsland region between the cities of Derpen and Lathen. The history of the Emsland maglev, however, ended tragically: in 2006, due to the fault of technicians, there was a serious accident in which 23 people died, and the line was mothballed.

In Japan, two magnetic levitation systems are currently in operation. The first (for urban transportation) uses an electromagnetic suspension system for speeds up to 100 km/h. The second, better known, SCMaglev, is designed for speeds over 400 km/h and is based on superconducting magnets. As part of this program, several lines have been built and a world speed record for a railway vehicle, 581 km/h, has been set. Just two years ago, a new generation of Japanese maglev trains, the L0 Series Shinkansen, was introduced. In addition, a system similar to the German "Transrapid" operates in China, in Shanghai; it also uses superconducting magnets.

Salon TP-05 had two rows of seats and a central aisle. The car is wide and at the same time surprisingly low - the editor, 184 cm tall, almost touched the ceiling with his head. It was impossible to stand in the driver's cab.

And in 1975, the development of the first Soviet maglev began. Today it is almost forgotten, but it is a very important page in the technical history of our country.

Train of the future

It stands before us, a large, futuristic design that looks more like a spaceship from a sci-fi movie than a vehicle. Streamlined aluminum body, sliding door, stylized "TP-05" lettering on board. An experimental car on a magnetic suspension has been standing at a training ground near Ramenskoye for 25 years, the cellophane is covered with a thick layer of dust, under it is an amazing car that miraculously was not cut into metal according to the good Russian tradition. But no, it has survived, and so has the TP-04, its predecessor, designed to test individual units.

The experimental car in the workshop is already in a new coloring. It was repainted several times, and for filming in a fantastic short film, a large Fire-ball inscription was made on board.

The development of maglev goes back to 1975, when the Soyuztransprogress production association appeared under the Ministry of Oil and Gas Construction of the USSR. A few years later, the state program "High-speed environmentally friendly transport" was launched, within the framework of which work began on a train on a magnetic cushion. It was very good with funding, a special workshop and training ground of the VNIIPItransprogress institute with a 120-meter section of the road in Ramenskoye near Moscow was built for the project. And in 1979, the first TP-01 maglev car successfully passed the test distance under its own power - however, even on a temporary 36-meter section of the Gazstroymashina plant, the elements of which later "moved" to Ramenskoye. Pay attention - at the same time as the Germans and before many other developers! In principle, the USSR had a chance to become one of the first countries to develop magnetic transport - real enthusiasts of their work, headed by academician Yuri Sokolov, were engaged in the work.

Magnetic modules (grey) on rail (orange). Rectangular bars in the center of the photo are just gap sensors that track surface irregularities. The electronics were removed from TP-05, but the magnetic equipment remained, and, in principle, the car can be launched again.

The Popular Mechanics expedition was led by none other than Andrey Alexandrovich Galenko, General Director of the TEMP Engineering and Research Center. TEMP is the same organization, ex-VNIIPItransprogress, a branch of Soyuztransprogress, which has sunk into oblivion, and Andrei Alexandrovich worked on the system from the very beginning, and hardly anyone could tell about it better than him. TP-05 is standing under the cellophane, and the first thing the photographer says is: no, no, we won't be able to take a picture of it, you can't see anything right there. But then we pull off the cellophane - and for the first time in many years the Soviet maglev appears before us, not engineers and not employees of the landfill, in all its glory.

Why do you need a maglev

The development of transport systems operating on the principle of magnetic levitation can be divided into three areas. The first is cars with design speeds up to 100 km/h; in this case, the most optimal is the scheme with levitation electromagnets. The second is suburban transport with speeds of 100–400 km/h; here it is best to use a full-fledged electromagnetic suspension with lateral stabilization systems. And finally, the most “fashionable”, so to speak, trend is long-distance trains capable of accelerating to 500 km / h and more. In this case, the suspension must be electrodynamic, on superconducting magnets.

TP-01 belonged to the first direction and was tested at the test site until the middle of 1980. Its mass was 12 tons, length - 9 m, and it accommodated 20 people; the suspension gap was minimal - only 10 mm. TP-01 was followed by new gradations of testing machines - TP-02 and TP-03, the path was extended to 850 m, then the TP-04 laboratory car appeared, designed to study the operation of a linear traction electric drive. The future of the Soviet maglevs seemed cloudless, especially since in the world, in addition to Ramenskoye, there were only two such training grounds - in Germany and Japan.

Previously, TP-05 was symmetrical and could move both forward and backward; control panels and windshields were on both sides. Today, the console has been preserved only from the side of the workshop - the second was dismantled as unnecessary.

The operating principle of a levitating train is relatively simple. The composition does not touch the rail, being in a hovering state, the mutual attraction or repulsion of the magnets works. Simply put, the cars hang above the track plane due to vertically directed magnetic levitation forces, and are kept from side rolls using similar horizontally directed forces. In the absence of friction on the rail, the only "barrier" to movement becomes aerodynamic resistance - theoretically, even a child can budge a multi-ton car. The train is set in motion by a linear asynchronous motor, similar to the one that operates, for example, on the Moscow monorail (by the way, this motor was developed just by OAO INTS TEMP). Such an engine has two parts - the primary (inductor) is installed under the car, the secondary (reactive bus) - on the tracks. The electromagnetic field created by the inductor interacts with the tire, moving the train forward.

The advantages of maglev primarily include the absence of resistance other than aerodynamic. In addition, equipment wear is minimal due to the small number of moving parts of the system compared to classic trains. The disadvantages are the complexity and high cost of the routes. For example, one of the problems is safety: the maglev needs to be “lifted” onto the overpass, and if there is an overpass, then it is necessary to consider the possibility of evacuating passengers in case of an emergency. However, the TP-05 car was planned for operation at speeds up to 100 km / h and had a relatively inexpensive and technologically advanced track structure.

1980s Engineer VNIIPI-transprogress works on a computer. The equipment of the workshop at that time was the most modern - the financing of the program "High-speed environmentally friendly transport" was carried out without serious failures even in perestroika times.

Everything from scratch

Developing a series of TP, the engineers, in fact, did everything from scratch. We chose the parameters of the interaction between the magnets of the car and the track, then took up the electromagnetic suspension - worked on optimizing magnetic fluxes, driving dynamics, etc. passengers. Adaptation to unevenness was realized with the help of small electromagnets connected by hinges into something similar to chains. The circuit was complex, but much more reliable and workable than with rigidly fixed magnets. The control of the system was carried out thanks to the gap sensors, which tracked the unevenness of the path and gave commands to the power converter, which reduced or increased the current in a particular electromagnet, and hence the lifting force.

TP-01, the first Soviet maglev, 1979. Here the car is still not in Ramenskoye, but on a short, 36-meter section of track built at the test site of the Gazstroymashina plant. In the same year, the Germans demonstrated the first such car - Soviet engineers kept up with the times.

It was this scheme that was tested at TP-05, the only “second direction” car built under the program with an electromagnetic suspension. Work on the car was carried out very quickly - its aluminum body, for example, was made in just three months. The first tests of the TP-05 took place in 1986. It weighed 18 tons, accommodated 18 people, the rest of the car was occupied by test equipment. It was assumed that the first road using such wagons in practice would be built in Armenia (from Yerevan to Abovyan, 16 km). The speed should have been increased to 180 km / h, capacity - up to 64 people per car. But the second half of the 1980s made its own adjustments to the bright future of the Soviet maglev. In Britain, by that time, the first permanent magnetic cushion system had already been launched, we could have caught up with the British, if not for political upheavals. Another reason for the curtailment of the project was the earthquake in Armenia, which led to a sharp reduction in funding.

Project B250 - high-speed maglev "Moscow - Sheremetyevo". Aerodynamics was developed at the Yakovlev Design Bureau, and full-size mock-ups of the segment with seats and a cabin were made. Design speed - 250 km / h - was reflected in the project index. Unfortunately, in 1993, the ambitious idea crashed due to lack of funding.

Ancestor of Aeroexpress

All work on the TP series was curtailed in the late 1980s, and since 1990, TP-05, which by that time had managed to star in the sci-fi short film "You Don't Mess With Robots", was put on eternal joke under cellophane in the same workshop where it was built. We became the first journalists in a quarter of a century to see this car "live". Inside, almost everything has been preserved - from the control panel to the upholstery of the seats. The restoration of TP-05 is not as difficult as it could be - it was under a roof, in good conditions and deserves a place in the transport museum.

In the early 1990s, the TEMP Research and Development Center continued the maglev theme, now commissioned by the Moscow government. It was the idea of ​​Aeroexpress, a high-speed maglev train to deliver the capital's residents directly to Sheremetyevo Airport. The project was named B250. An experimental segment of the train was shown at an exhibition in Milan, after which foreign investors and engineers appeared in the project; Soviet specialists traveled to Germany to study foreign developments. But in 1993, due to the financial crisis, the project was curtailed. 64-seat cars for Sheremetyevo remained only on paper. However, some elements of the system were created in full-scale samples - suspension and running gear units, devices of the onboard power supply system, even tests of individual blocks began.

The most interesting thing is that there are developments for maglevs in Russia. JSC R&D Center "TEMP" works, various projects are being implemented for the civilian and defense industries, there is a test site, there is experience in working with similar systems. A few years ago, thanks to the initiative of Russian Railways, talk about maglev again moved to the stage of design development - however, the continuation of the work was entrusted to other organizations. Where this will lead, time will tell.

For help in preparing the material, the editors express their gratitude to the Director General of the ETC "Electromagnetic Passenger Transport" A.A. Galenko.

• Magnetic levitation trains are capable of reaching higher speeds than conventional trains.
• Magnetic levitation trains produce less noise than regular trains.
• Magnetic levitation trains reduce travel time for passengers.
• Magnetic levitation trains use sources of electrical energy that pollute the atmosphere to a lesser extent.

Disadvantages of maglev trains

• Maglev trains are more expensive than conventional trains.
• Magnetic levitation trains require special staff training.
• Superconducting maglev trains use powerful electromagnets mounted on the rail to create levitation. In this case, the task arises to shield passengers from the effects of strong magnetic fields.
• An unexpected drop in voltage will cause the carriages of the superconducting maglev train to sink onto the rail. At high speeds this can be dangerous (on Inductrack trains this is not a problem as the wheels of the train will allow the cars to coast to a complete stop).
• A strong lateral gust of wind can disrupt the operation of a maglev train by shifting the cars and causing them to come into contact with the rail. Snow or ice on the rail can also cause problems.

Question

How to isolate passengers from strong magnetic fields in a train with superconducting magnetic cushions?

Answer

Wagons or at least compartments can be made of ferromagnetic material (steel, for example) that blocks magnetic induction lines. Unfortunately, steel is much heavier than the aluminum commonly used in train construction. Aluminum is not ferromagnetic and does not provide protection against magnetic fields unless high voltage currents are applied to it, potentially dangerous to passengers.

Question

Will a maglev train overcome a steep hill or mountain? Won't it roll down the slope and stay in the valley if there is no friction to stop it?

Answer

Linear induction motors, used in maglev trains, are able to lift such trains up steeper slopes than conventional trains. What's more, the linear induction motors switch to reverse braking, preventing the train from rolling down by working against gravity.

Undoubtedly Shanghai Maglev- one of the attractions of Shanghai, and of all China. This is the world's first commercial magnetic railway and was commissioned in January 2004.

Now this 30-kilometer line connects with the Long "yang Lu metro station in the Shanghai area. This distance is covered by a magnetic cushion train in less than 8 minutes. For comparison, if you go by, it will take 40 minutes.

You need to ride such a train at least twice - once watching the speed indicator when it reaches its maximum, and the other time admiring the view from the window 🙂

Shanghai Maglev is built according to German technology. Active developments in this area are carried out mainly in Japan and Germany.

Magnetic pillow. How it works?

Maglev is short for magnetic levitation(magnetig levitation, English), that is, the train seems to levitate above the roadbed under the influence of a powerful electromagnetic field.

Electronically controlled electromagnets (1) are attached to the bottom of each car to a steel girth (4). Also, the magnets are located at the bottom of the special rail (2). When the magnets interact, the train hangs over the rail one centimeter. There are also magnets responsible for lateral alignment (3). The winding laid along the track creates a magnetic field that sets the train in motion.

The train travels without a driver. Management is carried out from the control center using computers. Electric current is supplied from the control center only to the section along which the train is currently moving. For braking, the magnetic field changes its vector.

Advantages and disadvantages

"If any of you decide to build a tower, won't he sit down first and calculate all the costs to see if he has enough money to finish it?" ( , Luke 14 chapter 28 verse)

These words contain one of the reasons why such trains were not made everywhere.

The construction and maintenance of a special gauge is expensive. For example, the construction of the Shanghai Maglev was further complicated by wetlands. Each support of the route is laid on a special concrete cushion resting against the rocky base. In some places, such a pillow reaches 85 meters in thickness! As a result, these 30 km of the magnetic road cost 10 billion yuan.

In addition, other vehicles can no longer be allowed on this road. This distinguishes it from tracks built for high-speed trains - regular ones can still travel on them.

Now about the pleasant. The main advantage of Maglev is, of course, the same speed. In a short time after the start, the train accelerates to 430 km per hour.

Relatively low power consumption - several times less than that of a car or aircraft. Accordingly, less harm to the environment.

Since the friction of parts is greatly reduced, the operating costs of such a train are also less.

Tests carried out have shown that the magnetic field in the train is even weaker than in conventional trains. This means that powerful magnets are not dangerous for passengers, including those with an electronic heart pacemaker.

Batteries are installed in the train in case of a power failure, on which special brakes work. They create a reverse vector magnetic field and the speed of the train is reduced to 10 km per hour, and eventually the train stops and falls on the tracks.

Future of Shanghai Maglev

Now the length of the maglev path is 30 km. It is known about plans to extend the line to another Shanghai airport - to Hongqiao, located to the west of. And then extend the road southwest to Hangzhou. As a result, the length of the path would be 175 km. But for now, the project is frozen until 2014. Since 2010, Shanghai and Hangzhou have been connected by high-speed rail. Whether plans to extend Maglev will be implemented - time will tell.

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 raise 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 modes 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 speed of rotation 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...

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