Advantages and load handling of permanent magnet motors

The air gap magnetic field in the motor, which is used for electromechanical energy conversion, can be generated by current excitation or permanent magnets. The motor in the world was a permanent magnet motor, but the magnetic function of the permanent magnet material used at that time was very low, and it was soon excited by electricity. replaced by motor. Later, with the rapid development of science and technology, permanent magnet motors became the popular equipment in the motor industry. This is because it has many advantages and is very good at load handling. Let’s learn about the advantages and load handling of permanent magnet motors!

The magnetic field is the basis for the motor to achieve electromechanical energy conversion. Permanent magnet motors can be divided into electric excitation motors and permanent magnet motors according to the different methods of establishing the magnetic field of the motor. Compared with electric excitation motors, permanent magnet motors have the following advantages:

1. The loss of the excitation system is eliminated, thereby increasing the power.

2. The excitation winding and excitation power supply are eliminated, and the structure is simple and the operation is reliable.

3. Rare earth permanent magnets have compact structure, small size and light weight.

4. The size and shape of the motor are flexible and diverse.

The load is handled as follows:

1. When the load is too heavy, we should consider appropriately reducing the load or replacing the motor with a suitable capacity.

2. When the power supply voltage is too high or too low, a three-phase power supply voltage stabilizing compensation cabinet needs to be installed.

3. When the motor is severely affected by moisture or corrosive gas for a long time, the insulation resistance will decrease. The staff should overhaul or replace the enclosed motor with the same capacity and standard according to the specific situation.

4. The bearing is short of oil, dry grinding or the rotor mechanism is not concentric, which causes the motor rotor to sweep, causing the motor current to exceed the rated value. First, you should carefully check the bearing wear. If it is not qualified, replace it with a new one; secondly, clean the bearing and inject an appropriate amount of grease. Then check the motor end cover. If the center hole of the end cover causes the rotor to be out of center due to wear, the end cover should be processed or replaced.

5. The transmission part of the mechanism fails, causing the motor to be overloaded and burning out the motor windings. Check for faults in the mechanical part and take measures.

Permanent magnet motors can not only partially replace traditional electric excitation motors, but also can complete high functions that are difficult to achieve with electric excitation motors. And the power of this motor ranges from MW level to 1000kW level. It has been widely used in industrial and agricultural production, aerospace, national defense and daily life, and its output has increased sharply.

Conventional permanent magnet motors are generally divided into the following five categories: permanent magnet DC motors, asynchronous starting permanent magnet synchronous motors, permanent magnet brushless DC motors, speed-regulated permanent magnet synchronous motors and permanent magnet synchronous generators.