Advantages of permanent magnet synchronous motor

Advantages of permanent magnet synchronous motor

1. High average efficiency

The excitation field of permanent magnet synchronous motor is provided by permanent magnet, the rotor does need excitation current, the motor efficiency is improved. Compared with asynchronous motor, any speed point can save electric energy, especially when the speed is low.

2. Starting torque

The permanent magnet synchronous motor adopts asynchronous starting mode, but because the rotor winding of the permanent magnet synchronous motor can play a corresponding role under normal operation, when designing the permanent magnet motor, the rotor winding can fully meet the requirements of high starting torque, for example, it can increase the starting torque by 1.8 times to 2.5 times, even more.

3. Small size light weight

Permanent magnet synchronous motor uses high-performance permanent magnet materials to provide magnetic field, which makes the air gap magnetic field of permanent magnet motor larger than induction motor, the volume weight of permanent magnet motor can be greatly reduced compared with induction motor.

4. Reduce grid load

Due to the low efficiency of asynchronous motor, in order to meet the demand of output power, it is bound to absorb more electric energy the grid, further increase the loss of electric energy increase the load of the grid. There is no induction current excitation in the rotor of permanent magnet motor, the power factor of the motor is high, which improves the quality factor of the power grid, so that there is no need to install compensator in the power grid. At the same time, because of the high efficiency of the permanent magnet motor, the electric energy is also saved.

The rotor of permanent magnet motor is made of rare earth permanent magnet material. The permanent magnet motor made of this material replaces the excitation part of the common motor to the rotor, eliminates the slip realizes synchronous operation.

In many cases, the efficiency of motor is less than 70% the power factor is less than 0.7 when the motor operates at 60% of rated load. The efficiency of PMSM can still reach 95% under light load, the power factor is less than 0.95, so the energy-saving effect is quite remarkable. At the same time, the structure of permanent magnet motor is simple, the temperature rise is low, the service life is also significantly improved

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、永磁同步電機