Table of Contents
- 1 Can a permanent magnet motor be used as a generator?
- 2 Why are magnetic motors not used?
- 3 Are permanent magnet motors more efficient?
- 4 Why permanent magnets are not preferred in motors?
- 5 What is the disadvantage of a permanent magnet?
- 6 Which is the major disadvantage of permanent magnet motor?
- 7 How is motor speed control of permanent magnet motors?
- 8 Can you drive a motor with magnets alone?
- 9 Could a new discovery lead to commercial production of permanent magnet motors?
- 10 Is a magnet motor a synchronous motor?
Can a permanent magnet motor be used as a generator?
Permanent magnet direct current (DC) machines can be used as either conventional motors or as DC wind turbine generators as constructionally there is no basic difference between the two. This then makes the permanent magnet DC generator (PMDC generator) ideal for use as a simple wind turbine generator.
Why are magnetic motors not used?
Practical implementations fail because there is no substantial energy in magnets that could be employed for propulsion or to compensate for energy losses. The force between permanent magnets is conservative as the magnetic field follows a potential, so that there is no work done over a closed cycle.
What are two advantages of a permanent magnet type starter motor?
They have specific benefits, including:
- Portability in size.
- Less expensive.
- Lower manufacturing costs.
- Do not require field winding.
- No field circuit copper losses.
- Increased efficiency overall.
- Multiple application use.
Are permanent magnet motors more efficient?
Permanent magnet motors offer significant efficiency improvements over AC Induction Motors. A permanent magnet motor’s full load efficiency is higher than an AC induction motor.
Why permanent magnets are not preferred in motors?
The reason that permanent magnets are not used widely is because they are not suited to motors that drive loads with extremely high torques. Also there is little control over the field produced by a permanent magnet.
Why no permanent magnet asynchronous motors exist?
Rotor (field) is a rotating electromagnet. Field excitation of the alternator needs to be changed frequently (which is done using AVR) in order to keep the terminal voltage constant and to control the reactive power flow. Hence, permanent magnets are not used in power plant generators.
What is the disadvantage of a permanent magnet?
There is a risk of demagnetization of the poles which may be caused by a large armature current. Demagetizatiob cab also occurs due to excessive heating and also when the motor is an overload for a long period of time.
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.
Are permanent magnet motors brushless?
The term “brushless DC” is often given to Permanent magnet motors, as it describes the key advantage over conventional DC motors of not requiring any brushgear. Because there is no need for rotor windings (or bars) and their attendant losses, the efficiencies of these motors can be exceptionally high.
How is motor speed control of permanent magnet motors?
A permanent magnet (PM) motor is an ac motor that uses magnets imbedded into or attached to the surface of the motor’s rotor. Controlling the speed of ac motors is accomplished using a variable frequency drive (VFD) in most cases.
Can you drive a motor with magnets alone?
Scientists and inventors alike have attempted to use permanent magnets alone to drive a motor. Others dismissed the notion of a motor driven by permanent magnets alone as defying the laws of thermodynamics. We did not understand the source of the electromagnetic energy responsible for the magnetic forces.
What is the difference between permanent magnet motor and hybrid motor?
The permanent magnet motor tends to have larger step angles, 7.5° or 15°, than the variable reluctance motor. The hybrid motor typically has 200 rotor teeth and rotates at 1.8° step angles. They have high static and dynamic torque and can run at very high step rates.
Could a new discovery lead to commercial production of permanent magnet motors?
It should have said, “New Discovery Could Lead to Commercial Production of Permanent Magnet Motors.” The original article’s co-author, Dr. Kenneth Kozeka, discovered a way to use permanent magnets to produce mechanical motion. The article should have made it clear that this discovery could lead to a permanent magnet motor, but not yet.
Is a magnet motor a synchronous motor?
The magnets in a permanent magnet motor, when properly arranged in relation to the stator, can provide speeds equal to the excitation current frequency, and so are considered a synchronous motor (see our related article all about synchronous motors to learn more).