Advantages of permanent magnet synchronous motor
1. High average efficiency
The excitation field of permanent magnet synchronous motor is provided by the permanent magnet, the rotor does need the excitation current, the motor efficiency is improved, compared with the asynchronous motor, any speed point can save power, especially when the speed is low.
2. Starting torque
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, such as the doubling of 1.8 times to 2.5 times, even larger.
3. Small size, light weight
The permanent magnet synchronous motor uses a high-performance permanent magnet material to provide a magnetic field, so that the air gap magnetic field of the permanent magnet motor is larger than that of the induction motor, the volume weight of the permanent magnet motor can be greatly reduced compared with the induction motor.
4, reduce the power grid load
Due to the low efficiency of the asynchronous motor, in order to meet the requirements of the power output, it is bound to absorb more electric energy the grid, further increasing the loss of power energy, increasing the load of the grid. There is no induction current excitation in the rotor of the permanent magnet motor, the power factor of the motor is high, which improves the quality factor of the power grid makes it no longer necessary to install compensators in the power grid. At the same time, because of the high efficiency of the permanent magnet motor, it also saves electric energy.
The rotor of the 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 ordinary motor to the rotor, eliminates the slip, realizes synchronous operation.
In many workplaces, motors generally operate at about 60% of the rated load with an efficiency of less than 70% a power factor of less than 0.7. The efficiency of permanent magnet synchronous motor in light load can still reach 95%, the power factor is less than 0.95, the energy saving effect is quite significant. At the same time, the structure of the permanent magnet motor is simple, the temperature rise is low, the service life is also significantly improved
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、永磁同步电机