What is the use of PMG in alternator?
What is the use of PMG in alternator?
The PMG (Permanent Magnet Generator) is a system which is used for secondary exciting. The PMG provides stable and reliable electric energy for AVR regardless the generator’s terminal voltage. The generator with PMG excitation system can provide 300 \% rated current during short-circuit, which occurs for 5-10 seconds.
Why permanent magnet generator PMG does not require a DC supply for the excitation circuit?
Permanent magnet generators (PMGs) or alternators (PMAs) do not require a DC supply for the excitation circuit, nor do they have slip rings and contact brushes. A key disadvantage in PMAs or PMGs is that the air gap flux is not controllable, so the voltage of the machine cannot be easily regulated.
What are the pros and cons of a permanent magnet generator?
| Advantages | Disadvantages |
|---|---|
| No power supply needed | Direct field only |
| Cling to vertical surfaces | Deteriorate with wear |
| No electrical contact problems | Have to be pulled from test surface |
| Inexpensive | No control over field strength |
What is the advantage of PMG?
The advantage from the PMG is that the power to the AVR is kept near constant, allowing the AVR to quickly recover the voltage of the AC generator back to its nominal preset value. The AVR reacts quicker reducing the transient voltage dip associated with applying a load to an AC alternator.
What are the advantages of permanent magnet synchronous generator?
Permanent magnet synchronous generator offers a variety of advantages such as: reliability, compact size, loss reduction, higher power density and finally optimal efficiency [4]-[6].
What are the advantages of permanent magnet starters?
Key Advantages of Permanent Magnet DC Motors
- Portability in size.
- Less expensive.
- Lower manufacturing costs.
- Do not require field winding.
- No field circuit copper losses.
- Increased efficiency overall.
- Multiple application use.
What is the disadvantage of a permanent magnet?
Its rotor has constant magnetic but it needs the variable magnetic field so these motors want to variable frequency power source to start. Permanent magnet synchronous motors require a drive to operate it cannot run without a driver.
Which is the major disadvantage of permanent magnet motor?
Disadvantages of the Permanent Magnet DC Motor There is a risk of demagnetization of the poles which may be caused by large armature currents. Demagnetization can also occur due to excessive heating and also when the motor is overloaded for a long period of time.
What is the advantage of permanent magnet?
The main advantage of a permanent magnet over an electromagnet is that a permanent magnet does not require a continuous supply of electrical energy to maintain its magnetic field.