A permanent magnet synchronous motor does not need to draw current from the power grid to produce the necessary magnetic field of the motor, so compared with an ordinary electric excitation motor, the permanent magnet synchronous motor is bound to be energy-efficient. For motors of different power levels, the savings of this part of excitation energy affect the efficiency of the motor is about 2% to 5%. The three-phase permanent magnet synchronous motor runs at synchronous speed (speed and frequency to maintain a fixed relationship), so when the three-phase permanent magnet synchronous motor is directly powered by the grid, its power factor is much higher than the three-phase induction motor. Generally can be close to 1.0, so can reduce the grid current amplitude by about 10% to 15%, and power grid transmission loss reduced by 20% to 28%.
Low work temperature increase:
When the asynchronous motor is working, the rotor winding has a flow of current, which is completely consumed in the form of heat, so a large amount of heat will be generated in the rotor winding, which increases the temperature of the motor, affecting the life of the motor. Due to the high efficiency of the permanent magnet motor, there is no resistance loss in the rotor winding, there is little or no reactive current in the stator winding, which makes the motor temperature rise low, and extends the life of the motor.