Do Large Generators Really Use Permanent Magnets?

In summary, the conversation discusses the use of permanent magnets in generators, specifically in large power plants. The efficiency and power generation of using permanent magnets compared to electromagnets is also mentioned, with a reference to a website claiming higher efficiency. The development of high energy permanent magnets is noted as a factor in making permanent magnet synchronous generators more competitive.
  • #1
cj
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0
I frequently teach my students about how basic generators work (motional EMFs, Faraday's Law, magnetic flux, etc.).

Question: do the generators used at large power plants really use a permanent magnet as a source of the magnetic field?

I was thinking that maybe an electromagnet might be used as the source, but I'm not sure. Plus I'm thinking that providing the electricity to this kind of electromagnet might significantly offset the generated electical energy that is produced.
 
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  • #2
The field is an electromagnet. This is the way the voltage is regulated by varying the current in the field.
 
  • #3
For generators and motors, how practical is using a permanent magnet with repsect to an electromagnet? In other words, how does the efficiency and power generation compare?
 
  • #4
I found this http://www.windturbines.net/wiki/Synchronous_Generators". The author(s) of that page have claimed higher efficiency for permanent magnet synchronous generators than for the wound rotor type. But there are other issues with permanent magnet synchronous generators.

I have read the development of high energy permanent magnets (such as Nd2Fe14B magnets) have made permanent magnet synchronous generators more competitive with other types of generator.
 
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Related to Do Large Generators Really Use Permanent Magnets?

1. How do permanent magnets work in large generators?

Permanent magnets work by creating a magnetic field that interacts with the moving parts of a generator to produce electricity. In large generators, permanent magnets are used in conjunction with other components, such as coils and stators, to generate electricity.

2. What are the benefits of using permanent magnets in large generators?

Using permanent magnets in large generators can increase efficiency and reduce maintenance costs. They also have a longer lifespan compared to traditional electromagnets, and do not require a continuous supply of electricity to maintain their magnetic field.

3. How do large generators with permanent magnets differ from traditional generators?

In traditional generators, the magnetic field is created by passing an electric current through coils. In generators with permanent magnets, the magnetic field is created by the permanent magnets themselves, eliminating the need for an external power source.

4. Are there any limitations to using permanent magnets in large generators?

While permanent magnets have many benefits, they may not be suitable for all types of generators. They are best suited for smaller, high-speed generators, and may not provide enough power for larger, industrial generators.

5. Are large generators with permanent magnets more expensive?

Initially, generators with permanent magnets may be more expensive to manufacture. However, in the long run, they can save money on maintenance and energy costs. It ultimately depends on the specific application and needs of the generator.

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