How does the maglev train work?

Maglev train is a new type of transportation composed of non-contact electromagnetic levitation, guidance and drive systems, and maglev trains are divided into two categories: superconducting and normal. To put it simply, from the perspective of internal technology, there is a difference between the two systems that use magnetic repulsion or magnetic attraction. Externally, there is a difference in speed between the two:

The maximum speed of superconducting maglev trains can reach more than 500 kilometers per hour (the maximum speed of high-speed wheel-rail trains is generally 300-350 kilometers per hour), and can compete with aviation within a distance of 1000 to 1500 kilometers; The speed of the permanent maglev train is 400 500 kilometers per hour, and its medium and low speed is more suitable for long-distance rapid transportation between cities.

The Shanghai maglev train is a "permanent conduction magnetic suction type" (referred to as "permanent conductivity type") maglev train.

The technical basis of maglev trains.

The maglev train is mainly composed of three parts: the suspension system, the propulsion system and the guidance system, as shown in the figure. Although it is possible to use a propulsion system that is not magnetic, in the vast majority of current designs, these three functions are performed by magnetism.

How maglev trains work.

The maglev train uses the principle of "the same sex repels each other, and the opposite sex attracts", so that the magnet has the ability to resist gravity, so that the car body is completely off the track, suspended at a distance of about 1 cm from the track, and takes off, creating a miracle of almost "zero altitude" space flight.

How does the maglev train work?

Maglev trains are high-tech vehicles that use the attraction and repulsion of magnetic poles.

The repulsive force makes the train hang, and the attraction makes the train move.

The maglev train carriage is equipped with superconducting magnets, and coils are installed at the bottom of the railway. After being energized, the polarity of the magnetic field generated by the ground coil and the polarity of the electromagnet in the carriage are always the same, and the two are "same sex repellent".

The repulsive force levitates the train, the power of the conventional locomotive comes from the locomotive head, and the power of the maglev train comes from the track. The tracks are equipped with coils on both sides, and the alternating current turns the coils into electromagnets, which interact with the magnets on the train. When the train is moving, the magnet at the front of the locomotive (n pole) is attracted by the electromagnet (S pole) a little earlier on the track, and at the same time is repelled by the electromagnet (n pole) a little later on the track——— the result is that the front "pulls" and the back "pushes" to make the train move forward.

Linear synchronous motor: its primary winding is laid along the track, the secondary winding is installed on the car body, three-phase alternating current is introduced into the primary winding, and the translational magnetic field is generated in the air gap, which cuts the secondary conductor, generates electromagnetic induction, and induces a magnetic field, which is opposite to the original translational magnetic field, and finally generates electromagnetic thrust between the rail and the car body.

In recent years, the maglev train has gradually appeared in people's sight, and the maglev train, as the name suggests, can make the train levitate on the rails, and the friction between the train wheels and the rails on it has greatly improved the running speed of the train. So what is the principle of the maglev train? Why is it able to float on the railroad tracks?

Although it is said that the operating principle of the train is mainly to use electromagnetic force to counteract the gravitational pull of the earth, and then pull it through a linear motor, so that the train is suspended on the earth's orbit. Children who have played with magnets when they are young know the principle of same-sex repulsion and opposite-sex attraction, and the maglev train also uses this principle. Compared with ordinary trains, maglev trains have the characteristics of low noise, no pollution, safe and comfortable, high efficiency and high speed, and have the reputation of zero-altitude aircraft.

Maglev train is a new type of transportation with broad prospects, especially suitable for urban rail transit resources and trains, according to the different suspension methods can also be divided into super-inverted repulsion type and Changdao magnetic type, according to the speed of operation also has high-speed and low-speed points.

The vehicle of the superconducting maglev train is equipped with a vehicle-mounted superconducting magnet and constitutes an induction power integration device, and the induction power integration equipment on the train is composed of three parts: a power integration winding, an induction power integrated superconducting magnet and a levitation guide superconducting magnet. When the drive windings on both sides of the track provide three-phase alternating current with the same speed and frequency of the vehicle, a moving electromagnetic field occurs, so the train is able to generate this wave on the track and propel the train forward.

The maglev train overcomes the main obstacle of the traditional rail railway to increase the speed, and the development prospect is very broad, because the speed of the maglev train is very high, and the energy consumption is relatively low. However, there are also problems with maglev trains, because the maglev system uses electromagnetic force to complete the suspension guidance and drive, and the safety measures of maglev trains after power failure still need to be solved.

Maglev trains are manufactured using the principle of electromagnet repulsion of the same sex. After the maglev train is energized, a huge magnetic field will be generated, which will make the train float, and the maglev train will not be in contact with the rails, and the resistance will be very small during operation, and it can reach very high speeds.

The principle of the maglev train is equivalent to the principle of mutual attraction and mutual repulsion between magnets, using magnetic force to counteract the effect of the earth's gravity, and then levitating the train through the principle of mutual repulsion of magnets, so the maglev train has low noise and fast speed.

The basic principle of the maglev train is to use the electromagnetic principle of "the same sex repels each other, the opposite sex attracts", so that the magnet resists gravity, makes the vehicle levitate, and then uses electromagnetic force to guide and push the train forward.

The principle adopted by the maglev train is the principle of opposite-sex repulsion, and then the electromagnetic force is used to derive it, so that the train can be powered and the train can move forward.

Maglev train is a modern high-tech rail transportation tool, which realizes contactless suspension and guidance between the train and the track through electromagnetic force, and then uses the electromagnetic force generated by the linear motor to pull the train to run.

At present, maglev trains can be divided into two types: one is electromagnetic levitation trains; One is a superconducting maglev train.

Whether it is electromagnetic levitation or superconducting levitation, it uses electrical excitation, and then uses the attraction or repulsion of the magnetic field. This has little to do with the magnets (permanent magnets) we use in our daily lives.

Electromagnetic levitation train (attraction) Electromagnetic levitation train is to use electricity to make the electromagnet produce ferromagnetism, use the attraction of the electromagnet to separate the track and the carriage, and control the size of the suspension gap by changing the excitation current. Shanghai's maglev train is based on this principle.

Superconducting Maglev Train (Repulsion): Superconducting Maglev Train uses the repulsive force between the magnetism generated by electricity and the superconductor in the superconducting state to levitate the carriage. Superconductors are completely diamagnetic in the superconducting state and can float in a magnetic field. Completely diamagnetism is actually the superconductor induces a superconducting current in a magnetic field, and the current generates a magnetic field to cancel out the external field.

It is to use electromagnetic force to counteract the gravitational pull of the earth, and pull through a linear motor, so that the train is suspended on the track (the suspension gap is about 1 cm).

Maglev trains are divided into two categories: normal and superconducting. The normal conductive type, also known as the normal conductive magnetic attraction type, is represented by the German high-speed constant conduction maglev train Transrapid, which uses the principle of electromagnetic attraction of ordinary DC electromagnets to suspend the train, and the suspended air gap is small, generally about 10 mm. The speed of the constant-conducting high-speed maglev train is suitable for long-distance rapid transportation between cities.

When the normal conduction maglev train is working, the electromagnetic attraction of the suspension and guiding electromagnets at the lower part of the vehicle is first adjusted, and the magnets react with the windings on both sides of the ground track. The suspension gap between the vehicle and the track is 10 millimetres, which is ensured by a high-precision electronic adjustment system. In addition, since the suspension and guidance are practically independent of the speed of the train, the train can still enter the suspension state even when it is parked.

<> maglev technology is divided into four major systems: track, vehicle, traction and operation control, with 16 core technologies. Germany, Japan and China are the countries in the world that currently have maglev train test or operating routes. Maglev trains are guided by the action of electromagnetic force.

Now according to the two cases of normal conductive magnetic attraction and superconducting magnetic repulsion.

Trains are a familiar means of transportation for people living in modern times. Two rails lay on the railroad, and the wheels of the train rushed forward along the tracks, making a clanging sound and whistling past.

But this traditional train will be replaced by another train in the near future, which is the train on the maglev railway. The carriage is suspended in the air, and the speed is up to 500 kilometers per hour, and people who are in Shanghai in the morning can get to Beijing at noon on this kind of train.

The speed of ordinary trains will not exceed 300 kilometers per hour at the earliest, and the speed of ordinary trains in China is only about 70 kilometers per hour. This is due to the frictional force that exists between the wheels of the train and the tracks. The maglev railway, on the other hand, does not have such a problem, because it is suspended in the air.

How was the maglev railway designed? Anyone who has fiddled with magnets should easily understand why the train of the maglev railway can float in the air. When we put a magnet of that.

When the poles and the s pole of another magnet come close together, they immediately suck together. But if you put a magnet. pole and another magnet.

Extremely close, they are always close together, and even if they are squeezed together, as soon as they let go, they will immediately separate, because there is a repulsive force between them. This is called "repulsion of the same poles".

The maglev railway is made by using the principle of magnets repelling the same poles. The train and the rails are specially designed, and after being electrified, because the magnetic fields of the trains and rails are repulsed by the same poles, the train is "topped" by the repulsive force of the magnetic field.

In the early 90s of the 20th century, China began to develop a maglev railway, and has developed the first experimental maglev train. The maglev train developed by developed countries has reached a speed of more than 500 kilometers per hour. Maybe in the near future, you will be able to ride it and experience the feeling of "flying" on flat ground.