Electromagnetic levitation train. – more economical than a high-speed line

Undoubtedly Shanghai Maglev- one of the attractions of Shanghai, and all of China. This is the world's first commercial magnetic Railway was put into operation 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 levitation 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 the maximum, and another time admiring the view from the window :)

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

Magnetic pad. How it works?

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

Controlled electronically electromagnets (1). Also, magnets are located at the bottom of the special rail (2). When the magnets interact, the train hovers one centimeter above the rail. 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. Electricity is supplied from the control center only to the area along which it moves in this moment train. To decelerate, the magnetic field changes its vector.

Advantages and disadvantages

"If any of you decides to build a tower, won't he first sit down and count 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 built 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 track support is laid on a special concrete pad resting on a rocky base. In some places this pillow reaches 85 meters in thickness! As a result, these 30 km of magnetic road cost 10 billion yuan.

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

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

Relatively low electricity consumption - several times less than that of a car or airplane. Accordingly, there is less harm to the environment.

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

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

In case of power loss, the train is equipped with batteries that activate special brakes. They create a magnetic field with a reverse vector, and the speed of the train is reduced to 10 km per hour, and eventually the train stops and falls onto the tracks.

The 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 to the southwest to Hangzhou. As a result, the length of the route 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. Time will tell whether plans to extend Maglev will be implemented.

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

1. Purpose

Magnetic levitation train or maglev(from the English magnetic levitation, i.e. “maglev” - magnetic plane) is a magnetically suspended train, driven and controlled by magnetic forces, designed to transport people (Fig. 1). Refers to passenger transport technology. Unlike traditional trains, it does not touch the surface of the rail while moving.

2. Main parts (device) and their purpose

There are different technological solutions in the development of this design (see paragraph 6). Let's consider the principle of operation of the magnetic levitation of the Transrapid train using electromagnets ( electromagnetic suspension, EMS) (Fig. 2).

Electronically controlled electromagnets (1) are attached to the metal “skirt” of each car. They interact with magnets on the underside of a special rail (2), causing the train to hover above 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 operating principle of a maglev train 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, 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 in the absence of a 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 Emilius Christianovich Lenz.

Let's consider a closed circular current-carrying circuit without a connected battery or other power source, into which a magnet is inserted with the north pole. This will increase the magnetic flux passing through the loop, and, according to Faraday's law, an induced current will appear in the loop. This current, in turn, according to the Bio-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 driven magnet. Since mutual repulsion forces act between the two north poles of the magnets, the induction current induced in the circuit will flow in precisely the direction that will counteract the introduction of the magnet into the circuit. And this is only a special case, but in a generalized formulation, Lenz’s rule states that the induced current is always directed in such a way as to counteract the root cause that caused it.

Lenz's rule is precisely what is used today in magnetic levitation trains. Powerful magnets are mounted under the bottom of the car of such a train, located a few centimeters from the steel sheet (Fig. 3). When the train moves, the magnetic flux passing through the contour of the track 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 contour and the magnet in the experiment described above). This force is so great that, having gained some speed, the train literally lifts off the track by several centimeters and, in fact, flies through the air.

The composition levitates due to the repulsion of identical poles of magnets and, conversely, the attraction of different poles. The creators of the TransRapid train (Fig. 1) used an unexpected magnetic suspension scheme. They did not use the repulsion of poles of the same name, but the attraction of opposite poles. Hanging a load above a magnet is not difficult (this system is stable), but under a magnet is almost impossible. But if you take a controlled electromagnet, the situation changes. The control system keeps the gap between the magnets constant at several millimeters (Fig. 3). As the gap increases, the system increases the current strength in the supporting magnets and thus “pulls” the car; when decreasing, the current decreases and the gap increases. The scheme has two serious advantages. Track magnetic elements are protected from weather influences, and their field is significantly weaker due to the small gap between the track and the train; it requires much lower 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 stator stretched into strips (in a conventional electric motor they are rolled into rings). The stator windings are switched on alternately, 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 alternately supplying and removing current at a frequency of 4,000 times per second. The gap between the stator and the rotor should not exceed five millimeters to obtain reliable operation. This is difficult to achieve due to the swaying of the cars during movement, which is characteristic of all types of monorail roads, except for roads with side suspension, especially when cornering. Therefore, an ideal track infrastructure is necessary.

The stability of the system is ensured by automatic regulation of the current in the magnetization windings: sensors constantly measure the distance from the train to the track and the voltage on the electromagnets changes accordingly (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 movement diagram of a maglev train: supporting 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 current in the windings continuously changes, switching magnetic fields as the train moves.

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

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

Check out the video clips " Law of Electromagnetic Induction», « Electromagnetic induction» « Faraday's experiments».

Rice. 6. b Stills from video fragments “The Law of Electromagnetic Induction”, “Electromagnetic Induction”, “Faraday’s Experiments”.

Magnetoplane 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 moving surface, friction is eliminated, and the only braking force is the force of aerodynamic drag.

The speed achievable by Maglev is comparable to that of an airplane and allows it to compete air services at short (for aviation) distances (up to 1000 km). Although the idea of ​​such transport is not new, economic and technical limitations have prevented it from being fully developed: the technology has only been implemented for public use 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 highway.

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

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

The “railway of the future” created in Germany has previously caused protests from Shanghai residents. But this time the authorities, frightened by demonstrations threatening to lead to major unrest, promised to deal with the trains. In order to stop demonstrations in a timely manner, officials even hung video cameras in places where mass protests most often occur. The Chinese crowd is very organized and mobile, it can gather in a matter of seconds and turn into a demonstration with slogans.

These are the largest popular demonstrations in Shanghai since anti-Japanese marches in 2005. This is not the first protest caused by Chinese concerns about the deteriorating environment. Last summer, crowds of thousands of demonstrators forced the government to postpone construction of the chemical complex.

Magnetic levitation trains are environmentally friendly, silent and fast transport. They cannot fly off the rails and, in the event of a problem, are able to stop safely. But why has such transport not become widespread, and people still use ordinary electric trains and trains?

Magnetic levitation trains: why the “transport of the future” has not caught on

In the 1980s, magnetic levitation (maglev) trains were believed to be the transport of the future that would destroy domestic air travel. These trains can carry passengers at speeds of 800 km/h and cause virtually no harm to the environment.

Maglevs are able to travel in any weather and cannot leave their only rail - the further the train deviates from the tracks, the more magnetic levitation pushes it back. All maglevs move at the same frequency, so there will be no problems with the signals. Imagine the effect such trains would have on the economy and transport if the distance between distant major cities was overcome in half an hour.

But why can't you still drive to work at supersonic speeds in the morning? The concept of maglevs has been around for over a century, with numerous patents using the technology dating back to the early 1900s. However, only three working magnetic levitation train systems have survived to this day, all of them only in Asia.

Japanese Maglev. Photo: Yuriko Nakao/Reuters

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Before this, the first working Maglev appeared in the UK: between 1984 and 1995, an AirLink shuttle operated from Birmingham Airport. The maglev was a popular and cheap transport, but its maintenance was very expensive, since some spare parts were one-off and hard to find.

In the late 1980s, Germany also turned to the idea, with its driverless M-Bahn train running between three stations in West Berlin. However, they decided to postpone the technology of levitating trains for later, and the line was closed. Its manufacturer, TransRapid, tested maglevs until an accident occurred at the La Tène training site in 2006, killing 23 people.

This incident could have put an end to the German maglevs if TransRapid had not previously signed a contract for the construction of a maglev for Shanghai Airport in 2001. Now this maglev is the fastest electric train in the world, traveling at a speed of 431 km/h. With its help, the distance from the airport to the business district of Shanghai can be covered in just eight minutes. On ordinary transport this would take a whole hour. China has another medium-speed maglev (its speed is about 159 km/h), which operates in the capital of Hunan province, Changsha. The Chinese love this technology so much that by 2020 they plan to launch several more maglevs in 12 cities.

German Chancellor Angela Merkel was the first to ride a TransRapid maglev to Shanghai Airport. Photo: Rolf Vennenbernd/EPA

In Asia, work is currently underway on other magnetic levitation train projects. One of the most famous is the EcoBee self-driving shuttle, which has been operating from South Korea's Incheon Airport since 2012. On his own short line There are seven stations, between which the maglev rushes at a speed of 109 km/h. And trips on it are absolutely free.

The first magnetic levitation 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 collecting dust on the outskirts of history for more than 30 years.

Tim Skorenko

Experiments with transport operating on the principle of magnetic levitation began even before the war. IN different years and in different countries working 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 magnetic levitation trains appeared at Birmingham International Airport (UK). The initial length of the route 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 since the system was unique, almost any spare part had to be manufactured according to individual order, and it was decided to close the line, which was bringing continuous losses.

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

In addition to the British, serial magnetic trains They launched everything quite successfully in Germany - the Transrapid company operated a similar system 31.5 km long in the Emsland region between the cities of Derpen and Laten. The story of the Emsland Maglev, however, ended tragically: in 2006, due to the fault of technicians, a serious accident, in which 23 people died, and the line was mothballed.

There are two magnetic levitation systems in use in Japan today. The first (for urban transport) 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 were built and a world speed record for a railway vehicle was set, 581 km/h. Just two years ago a new generation was introduced Japanese trains magnetic suspension - L0 Series Shinkansen. In addition, a system similar to the German “Transrapid” operates in China, in Shanghai; it also uses superconducting magnets.

The TP-05 salon had two rows of seats and a central aisle. The car is wide and at the same time surprisingly low - the 184 cm tall editor practically 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 this is a very important page technical history our country.

Train of the future

He stands in front of us - large, futuristic in design, looking more like spaceship from a sci-fi movie rather than vehicle. Streamlined aluminum body sliding door, stylized inscription “TP-05” on the side. An experimental maglev car has been standing at a testing ground near Ramenskoye for 25 years, the cellophane is covered with a thick layer of dust, underneath is an amazing machine that miraculously was not cut into metal according to the good Russian tradition. But no, it was preserved, and TP-04, its predecessor, intended for testing individual components, was preserved.

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

The development of maglev goes back to 1975, when the USSR Ministry of Oil and Gas Construction appeared Production Association"Soyuztransprogress". A few years later it started Government program“High-speed environmentally friendly transport”, within the framework of which work began on a magnetic levitation train. The financing was very good; a special workshop and training ground of the VNIIPItransprogress Institute with a 120-meter section of road in Ramenskoye near Moscow was built for the project. And in 1979, the first magnetic levitation car TP-01 successfully passed the test distance under its own power - however, still on a temporary 36-meter section of the Gazstroymashina plant, elements of which were later “moved” to Ramenskoye. Please note - 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 - the work was carried out by real enthusiasts of their craft, led by Academician Yuri Sokolov.

Magnetic modules (gray) on a rail (orange). The rectangular bars in the center of the photo are gap sensors that monitor surface unevenness. The electronics were removed from TP-05, but the magnetic equipment remained, and, in principle, the car can be started again.

The Popular Mechanics expedition was led by none other than Andrey Aleksandrovich Galenko, General Director of the OJSC Engineering and Scientific Center TEMP. “TEMP” is the same organization, ex-VNIIPItransprogress, a branch of the Soyuztransprogress that has sunk into oblivion, and Andrei Aleksandrovich worked on the system from the very beginning, and hardly anyone could talk about it better than him. TP-05 stands under cellophane, and the first thing the photographer says is: no, no, we can’t photograph this, nothing is visible right away. But then we pull off the cellophane - and the Soviet Maglev for the first time in long years appears before us, not engineers or landfill employees, in all its glory.

Why do you need Maglev?

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

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

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

The operating principle of a levitating train is relatively simple. The composition does not touch the rail, being in a state of hovering - the mutual attraction or repulsion of magnets works. Simply put, the cars hang above the track plane thanks to the vertically directed forces of magnetic levitation, and are kept from lateral rolls by similar forces directed horizontally. In the absence of friction on the rail, the only “obstacle” to movement is aerodynamic resistance - theoretically, even a child can move a multi-ton carriage. The train is set in motion by a linear asynchronous motor, similar to what works, for example, on the Moscow monorail (by the way, this engine was developed by OJSC Scientific Center "TEMP"). Such an engine has two parts: the primary (inductor) is installed under the car, the secondary (reactive tire) is installed 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 elements 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 an 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 of up to 100 km/h and had a relatively inexpensive and technologically advanced track structure.

1980s An engineer from VNIIPI-transprogress works on a computer. The equipment of the workshop at that time was the most modern - the financing of the “High-Speed ​​Environmentally Friendly Transport” program was carried out without serious failures even during perestroika times.

Everything from scratch

When developing the TP series, the engineers essentially did everything from scratch. We selected the parameters for the interaction between the magnets of the car and the track, then took up the electromagnetic suspension - we worked on optimizing magnetic fluxes, motion dynamics, etc. The main achievement of the developers can be called the so-called magnetic skis they created, capable of compensating for track unevenness and ensuring comfortable dynamics of the car with passengers. Adaptation to unevenness was realized using small-sized electromagnets connected by hinges into something similar to chains. The circuit was complex, but much more reliable and efficient than with rigidly fixed magnets. The system was monitored thanks to gap sensors, which monitored track irregularities and gave commands to the power converter, which reduced or increased the current in a particular electromagnet, and therefore the lifting force.

TP-01, the first Soviet maglev, 1979. Here the car is not yet standing in Ramenskoye, but on a short, 36-meter section of track, built at the training ground of the Gazstroymashina plant. In the same year, the Germans demonstrated the first such carriage - Soviet engineers kept pace with the times.

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

Project B250 - high-speed maglev "Moscow - Sheremetyevo". Aerodynamics were developed at the Yakovlev Design Bureau, and full-size mock-ups of the segment with seats and cockpit were made. The 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 discontinued in the late 1980s, and since 1990, the TP-05, which by that time had managed to star in the science fiction short film “Robots are No Mess,” was put in permanent storage 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.” Almost everything inside has been preserved - from the control panel to the upholstery of the seats. Restoration of TP-05 is not as difficult as it could be - it stood under a roof, in good conditions and deserves a place in the transport museum.

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

The most interesting thing is that there are developments for maglevs in Russia. JSC Scientific Center "TEMP" is working and implementing various projects for the civilian and defense industries, there is a test site, there is experience working with similar systems. Several years ago, thanks to the initiative of JSC Russian Railways, conversations about maglev again moved to the design development stage - however, the continuation of work has already been entrusted to other organizations. Time will tell what this will lead to.

The editors would like to thank you for their assistance in preparing the material. to CEO ITC "Electromagnetic Passenger Transport" A.A. Galenko.