Sukhov Vitaly Vladimirovich, Galin Alexey Leonidovich

We present to you a project, the main theme of which is "Electromagnetic vehicles and apparatus". Having engaged in this work, we realized that the most interesting issue for us is magnetic levitation transport.

Recently, the famous English science fiction writer Arthur Clarke 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 said. - Then the current missiles will be what they were Balloons before the First World War ". What is this judgment based on? The answer must be sought in modern ideas of magnetic levitation transport.

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I-st open student scientific and practical conference

"My project activities in college"

Direction of the scientific and practical project:

Electrical engineering

Project theme:

Electromagnetic vehicles and apparatus. Magnetic Levitation Transport

Project prepared by:

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 No. 55

Project Manager:

Utenkova Eaterina Sergeevna

Moscow 2012

Introduction

Magnetoplane or Maglev

Halbach installation

Conclusion

Bibliography

Introduction

We present to you a project, the main theme of which is "Electromagnetic vehicles and apparatus". Having engaged in this work, we realized that the most interesting issue for us is magnetic levitation transport.

Recently, the famous English science fiction writer Arthur Clarke 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 said. "Then today's missiles will be what balloons were before World War I." What is this judgment based on? The answer must be sought in modern ideas of magnetic levitation transport.

Magnetoplane or Maglev

A 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 running surface, friction is eliminated and the only braking force is the aerodynamic drag force.

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

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 disadvantage of MAGLEV trains lies in the peculiarities of the operation of electromagnets, which ensure the levitation of cars above the track. Electromagnets that are not cooled to a state of superconductivity consume gigantic amounts of energy. When superconductors are used in the canvas, the cost of cooling them will negate all the economic advantages and the possibility of project implementation.

An alternative is suggested by physicist Richard Post of Lawrence Livermore National Laboratory, California. Its essence lies in the use of permanent magnets, not electromagnets. 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 the 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 the Post called the system - uses Halbach installations built into the bottom of the car. The web itself is an orderly laying of turns of insulated copper cable.

Halbach installation

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

Rice. 1 Halbach installation

The figure shows a 20 meter test bed for MAGLEV Inductrack trains, which contains about 1000 rectangular inductive windings, each 15 cm wide. In the foreground is the test carriage and the electrical circuit. Aluminum rails along the track support the cart 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 to levitate the train in the inductive windings. The force driving the train is generated by electromagnets 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 placement of Halbach's installations, the cars will not lose balance under any circumstances, until an earthquake. Currently, based on the success of Post's 1/20-scale demonstration work, NASA has signed a 3-year contract with its team at Livermore to further research the concept to more efficiently launch satellites into orbit. It is assumed that this system will be used as a reusable booster, which 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 tempting. Thus, the Japanese government is preparing to resume work on a fundamentally new type of ground transport - magnetic levitation trains. 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 trains take 2.5 times longer to do this.

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

Operational considerations for magnetic levitation vehicles

The Japanese are also worried about economic problems, and above all the question of the profitability of the super-high-speed Maglev line. Nowadays, about 24 million people travel between Tokyo and Osaka every year, 70% of passengers use the high-speed railway line. According to the calculations of futurologists, the revolutionary development of the computer communications network will inevitably lead to a decrease in passenger traffic between the two largest centers of the country. On workload transport lines the outlined drop in the number of active population of the country can also affect

The Russian project of opening magnetic levitation trains from Moscow to St. Petersburg will not be implemented in the near future, said Mikhail Akulov, head of the Federal Agency for Railway Transport, 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 magnetic levitation trains in winter conditions, Akulov said, saying that such a project was proposed by a group of Russian developers who have 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 topical today. In particular, it was proposed to combine the creation of a high-speed highway with the parallel construction of a highway. The head of the agency added that powerful business structures from Asia are ready to participate in this project, without specifying which structures are in question.

Train magnetic suspension technology

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 of a superconducting material. The superconducting winding has zero ohmic resistance. If such a winding is short-circuited, then the electric current induced in it remains practically indefinitely.

The magnetic field of a continuous current circulating through the winding of a superconducting magnet is extremely stable and free of pulsations, which is important for a number of applications in scientific research and technology. 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. Considering this, for the windings of superconducting magnets. materials with high values ​​of Тк, Iк and Нк are used.

2. On electromagnets (electromagnetic suspension, EMS).

3. On permanent magnets; it is a 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.

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.

There are many designs for linear motors now, but they can all be divided into two categories - low acceleration motors and high acceleration motors.

Low acceleration motors are used in public transport (maglev, monorail, subway). High acceleration motors are quite small in length and are usually used to accelerate an object to high speed and then release it. They are often used for research into hyperspeed collisions, like weapons or spacecraft launchers. Linear motors are also widely used in feed drives for machine tools and in robotics. 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.

According to S. Earnshaw's theorem (sometimes they write Earnshaw), static fields created by solely electromagnets and permanent magnets are unstable, in contrast to 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 movement of vehicles forward, under the influence of changes in magnetic fields. The arrangement of the magnets makes it possible for the car to be pulled forward to the opposite pole, thereby moving the entire structure.

The most detailed Sami magnetic installation is shown in the diagramdesigns of magnetic suspension and electric drive of the crew 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 - the body of the crew; 11, 12 - springs; 13 - damper; 14 - barbell; 15 - cylindrical hinge; 16 - sliding bearing; 17 - bracket; 18 - stop; 19 - bar. Von - magnetic field speed: Fn - lifting force suspension: Wb - the induction of the suspension working gap

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

Advantages and disadvantages of magnetic levitation transport

Dignity

• Theoretically the highest speed that can be obtained on a mass-produced (non-sport) ground vehicle.
• Low noise.

Flaws

• High cost of creating and maintaining track.
• Magnet weight, electricity consumption.
• The electromagnetic field generated by the magnetic suspension can be harmful to train crews and / or local 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 higher. It is also possible that the Maglev lines will be inaccessible to people using pacemakers.
• It will be necessary 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, an arrow for a maglev represents two sections of the road that alternate 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 Model train on magnetic levitation

Figure 2 shows a model of a magnetic levitation train, where the developers decided to turn the entire mechanical system upside down. A 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 over, 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 seems to be flying through the air. The distances between the supports are selected in such a way that at each moment of its movement the train is at least in two or three of them, and one carriage has a length greater than one span. This allows not only to keep the train suspended, 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 sufficient. Firstly, this is saving on materials, secondly, the weight of the train is significantly reduced (no engines or wheels are needed), thirdly, such a model is extremely environmentally friendly, and fourthly, to lay such a track in a densely populated city or terrain with uneven terrain, it is much easier than with standard modes of transport.

But one cannot fail to mention the shortcomings. For example, if one of the supports deviates strongly within the limits of the track, this will lead to a disaster. Although, disasters 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, just leaving a particular opening, if we talk in simple words, as it were, "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. Roughly the same situation occurs when the head of the train leaves the opening and also "hangs" 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 main wing, high 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 High-Speed ​​String Transport of Yunitskiy

As an alternative to this, there is a purely Russian development called Yunitskiy High-Speed ​​String Transport (UST). Within its framework, it is proposed to use prestressed rails-strings raised on supports to a height of 5-25 meters, along which four-wheeled transport modules move. The prime cost of UST turns out to be much lower - $ 600-800 thousand per one 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 behind the usual monorail performance. Moreover, within the framework of monorail systems, they are now rolling back the latest technology for transport automation. 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. You don't need a driver in these taxis (just like in science fiction books and films). You indicate the destination, and the taxi will take you there by itself, independently building the best route. Everything turns out 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 species 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, only one project of the magnetic road, also called Transrapid, is being implemented in practice in the world.

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 expensively, because a lot was spent on their transportation. The second problem is ecology, the third is the high 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 a transport with a magnetic cushion. Time moves ...

Bibliography

1. Drozdova T.E. Theoretical basis 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 of protection of inland waters from pollution and depletion / ed. I.K. Gavich - M .: UNITI-DANA, 2002 .-- 287 p.
4. Methods of industrial wastewater treatment / Zhukov A.I. Mongayt I.L., Rodziller I.D. - M .: Infra-M, 2005 .-- 338 p.
5. Fundamentals of technologies of the most important industries / ed. Sidorova I.A. University textbook. - M .: graduate 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.

• Magnetic levitation trains are capable of faster speeds than conventional trains.
• Magnetic levitation trains produce less noise than conventional trains.
• Magnetic levitation trains reduce travel times for passengers.
• Magnetic levitation trains use electrical energy sources that are less polluting to the atmosphere.

Disadvantages of magnetic levitation trains

• Magnet trains are more expensive than conventional trains.
• Magnetic levitation trains require special training of personnel.
• Superconducting magnetic levitation trains use powerful electromagnets mounted on a rail to create levitation. This raises the problem of shielding passengers from the effects of strong magnetic fields.
• An unexpected voltage drop will cause the cars of the superconducting magnetic levitation train to sink onto the rail. At high speed, this can be dangerous (when operating trains like Inductrack, such problems do not arise, since the wheels of the train will allow the cars to move by inertia until they come to a complete stop).
• A strong lateral gust of wind can disrupt the operation of a magnetic levitation train, displacing the carriages and causing them to come into contact with the rail. Snow or ice on the rail can also cause problems.

Question

How to insulate passengers from strong magnetic fields on a superconducting magnetic cushion train?

Answer

Carriages, or at least coupes, can be made of a ferromagnetic material (steel, for example) that blocks the lines of magnetic induction. 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 hazardous to passengers.

Question

Will the magnetic levitation train overcome a steep hill or mountain? Will it slide down the slope and stay in the valley if there is no friction to brake?

Answer

Linear induction motors, used in magnetic levitation trains, are capable of lifting such trains up steeper inclines than conventional trains. Moreover, linear induction motors switch to reverse braking, preventing the train from rolling downward by working against gravity.

More than 200 years have passed since the time when steam locomotives were invented. Since then railway transport became the most demanded for the transportation of passengers and goods. However, scientists have been actively working to improve this method of movement. The result was the creation of a maglev or magnetic levitation train.

The idea emerged in the early twentieth century. But it was not possible to realize it at that time and in those conditions. And only in the late 60s - early 70s in the Federal Republic of Germany they assembled a magnetic track, where they launched vehicle new generation. Then he moved at a maximum speed of 90 km / h and could only accommodate 4 passengers. In 1979, the magnetic levitation train was modernized, and it was able to carry 68 passengers, traveling 75 kilometers per hour. At the same time, a different variation of the Maglev was constructed in Japan. It accelerated to 517 km / h.

Today, the speed of magnetic levitation trains can be a real competitor to airplanes. The magnetoplane could seriously compete with air carriers. The only obstacle is that the Maglevs are unable to slide on regular railroad tracks. They require special highways. In addition, it is believed that the necessary air cushion a magnetic field can have adverse effects on a healthier person.

The magnetoplane does not move on rails, it flies in the truest sense of the word. At a low height (15 cm) from the surface of the magnetic track. It rises above the track due to the action of electromagnets. This explains the incredible speed.

A maglev canvas looks like a series of concrete slabs. The magnets are located under this surface. They artificially create a magnetic field through which the train "travels". There is no friction while driving, so aerodynamic drag is used for braking.

If on simple language explain the principle of action, it will turn out like this. When a pair of magnets is brought closer to each other with the same poles, they seem to repel one another. It turns out a magnetic pillow. And when the opposite poles approach, the magnets are attracted, and the train stops. This elementary principle is the basis for the operation of a magnetoplane, which moves through the air at a low altitude.

Today, 3 technologies of maglev suspension are used.

1. Electrodynamic suspension, EDS.

In other words, it is called on superconducting magnets, that is, on variations with a winding of a superconducting material. This winding has zero ohmic resistance. And if it is short-circuited, then the electric current in it persists for an infinitely long time.

2. Electromagnetic suspension, EMS (or electromagnets).

3. On permanent magnets. This is the least expensive technology today. The movement process is provided by a linear motor, that is, an electric motor, where one element of the magnetic system is open and has a deployed winding that creates a traveling magnetic field, and the second is made in the form of a guide, which is responsible for the linear movement of the moving part of the motor.

Many people think: is this a safe train, it will not fall? Of course, it will not fall. This is not to say that nothing keeps the Maglev on the road. It rests on the track by means of special "claws" located at the bottom of the train, in which there are electromagnets that lift the train into the air. There are also those magnets that keep the magnetoplane on the track.

Those who have ridden the Maglev say they have not experienced anything inspiring. The train is so quiet that the breathtaking speed is not felt. Objects outside the window fly by quickly, but are located very far from the track. The magnetoplane accelerates smoothly, so that overloads are not felt either. Interesting and unusual is only the moment when the train rises.

So, the main advantages of maglev:

• the maximum possible speed of movement, which is achieved by ground (non-sport) transport,
• a small amount of electricity is required,
• low maintenance costs due to the lack of friction,
• quiet movement.

Flaws:

• the need for large financial costs during the construction and maintenance of the track,
• the electromagnetic field can harm the health of those who work on these lines and live in the surrounding areas,
• to constantly monitor the distance between the train and the track, fast-acting control systems and heavy-duty instruments are required,
• a complex track layout and road infrastructure are required.

A 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 running surface, friction is eliminated and the only braking force is the aerodynamic drag force.

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

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

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

Created in Germany “ Railway of the future ”has provoked protests from Shanghai residents before. But this time, the authorities, frightened by the demonstrations that threaten to erupt into major unrest, promised to deal with the trains. In order to stop demonstrations in time, officials even put up video cameras in places where mass protests most often take place. 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 folk performances in Shanghai since the 2005 anti-Japanese marches. This is not the first protest caused by the Chinese concern about the deteriorating environment. Last summer crowds of thousands of protesters forced the government to postpone the construction of the chemical complex.

The Shanghai Maglev Train is the world's first commercial maglev railway and the most expensive railway project in China.

The project started commercial exploitation since January 1, 2004. Its cost is about 1.6 billion US dollars (10 billion yuan).

Such high costs were associated, first of all, with the fact that most of the route passes through swampy areas, which is why the builders had to build a concrete pad for each support of the flyover (and there are many of them here, every 25 meters). By the way, in some places the thickness of this very pillow reaches 70 m.

By the way, the Shanghai Maglev Line is not the longest of the expressways, its length is only 30 kilometers from Pudong International Airport to the Longyang Lu metro station in Shanghai.

But this distance "Shanghai Maglev" overcomes in just 7:20 or 8:10 minutes (depending on the time of day). The train has a top speed of 431 km / h, and its average speed is about 250 km / h.

True, with its maximum speed, it rushes for only 1.5 minutes, because there is nowhere to accelerate so much, the distance is not very large.

The line operates from 6:45 am to 9:30 pm, at intervals of 15 to 20 minutes.

The fare is about 7.3 USD one way. For passengers with air tickets - 5.81 USD. VIP tickets cost about twice as much as standard tickets.