How Eddy Currents Produce Attractive Electromagnetic Forces-Maglev

In summary: I found no mention of AC for the lifting magnets. AC lifting magnets might not work with the propulsion system.In summary, the Transrapid system uses attractive electromagnetic forces to suspend passengers.
  • #1
The Head
144
2
How Eddy Currents Produce Attractive Electromagnetic Forces--Maglev

Hello, I am working on a paper about maglev systems and am trying to describe attractive electromagnetic suspension systems, but I am having a little trouble exactly visualizing how this works, which from what I have read is due to magnetic fields through eddy currents. In repulsive electrodynamic suspensions systems, this all makes a lot of sense to me. The changing magnetic field runs through the surface of the tracks and sets up eddy currents that oppose the time-changing flux, which in turn create a magnetic field of their own. The result of the two magnetic fields is magnetic repulsion, due to the magnetic pressure between the two systems.

But how can eddy currents be used to explain the attraction. When I draw the diagrams of magnetic fields going through a conductor, I am only able to figure out a way to draw them such that the induced magnetic field is repulsive. Can anyone help me see how they can be attractive as well? Thank you!
 
Physics news on Phys.org
  • #2


I may have lead a sheltered life but I have only heard of repulsive maglev systems. Do you have a reference?
 
  • #3


The german Transrapid system works with attractive forces.
http://en.wikipedia.org/wiki/Transrapid
But the lifting has nothing to do with eddy currents.
 
  • #4


I was reading through several websites, though this is the one that mentioned an eddy current for attractive EMS:
http://www.hk-phy.org/energy/transport/trans_phy02_e.html

I can't vouch for the validity, and it seems like every website explains it a little differently, but the website's second diagram is good, and it is one I have seen on many sites. All in all, I am just having difficulty explaining the mechanism for induction. Anybody have a better idea than I at how the alternating current in the undercarriage of the train attracts the guideway (rail)?
 
  • #5


If I understand it correctly, there is iron in the undercarriage (as well as in the train electromagnets). So its a "simple" case of magnetic attraction.
I found no mention of AC for the lifting magnets. AC lifting magnets might not work with the propulsion system.
Eddy currents are used for distance sensors (according to your link, which I do not like very much) and for braking.
 

1. What are eddy currents and how do they produce attractive electromagnetic forces?

Eddy currents are circular currents induced in a conductor by a changing magnetic field. When a conductor is placed near a changing magnetic field, the magnetic field induces a current in the conductor. These currents create their own magnetic fields which interact with the original magnetic field, resulting in an attractive force between the two.

2. How are eddy currents used in Maglev technology?

In Maglev trains, strong electromagnets are placed on the train's undercarriage and a series of coils are embedded in the track. As the train moves, the changing magnetic field from the electromagnets induces eddy currents in the track. These currents create an attractive force that levitates the train above the track, allowing for frictionless movement.

3. What are the advantages of using eddy currents in Maglev technology?

Eddy currents allow for a frictionless and smooth ride, which results in less wear and tear on the train and track. They also eliminate the need for wheels and traditional tracks, reducing maintenance and increasing speed potential. Additionally, eddy currents produce minimal noise pollution, making Maglev trains a more environmentally friendly form of transportation.

4. What are some challenges associated with using eddy currents in Maglev technology?

One of the main challenges is controlling the strength and direction of the eddy currents to maintain a stable levitation of the train. This requires precise control of the electromagnets and the currents in the track. Another challenge is the cost of building and maintaining the necessary infrastructure for Maglev trains, which can be significantly higher than traditional train systems.

5. Are there any other applications of eddy currents besides Maglev technology?

Yes, eddy currents are used in a variety of industries and technologies. They are commonly used in metal detection systems, electromagnetic brakes, and speedometers. They also play a role in the functioning of electrical transformers and generators.

Similar threads

I Power Loss Due to An Eddy Current
    • Electromagnetism
Replies
3
Views
1K
I How Do Eddy Current Dampers Work in Space Applications?
    • Electromagnetism
Replies
4
Views
249
I Questions about cancelation of induced EMF and minimizing eddy currents
    • Electromagnetism
Replies
4
Views
964
How does an eddy current brake work exactly?
    • Introductory Physics Homework Help
Replies
1
Views
181
Are these instances of identical magnetic fields?
    • Electromagnetism
Replies
1
Views
1K
I An Alternative explanation for energy loss due to Eddy currents
    • Classical Physics
Replies
2
Views
657
A Voltage and current waves in a transmission line
    • Electromagnetism
Replies
4
Views
947
I Which does more work: gravitation or electromagnetism?
    • Electromagnetism
Replies
4
Views
826
I Hall effect -- is it always applicable?
    • Electromagnetism
Replies
7
Views
949
Question about eddy currents ?
    • Electromagnetism
Replies
3
Views
901

Hot Threads

Recent Insights

Back
Top