Permanent magnet synchronous motor is a kind of synchronous motor using permanent magnet as excitation source, which has the advantages of high efficiency, high torque density, small size, etc., is widely used in industry, transportation, home appliances other fields. This paper will introduce the working principle, characteristics application of permanent magnet synchronous motor.

The working principle of permanent magnet synchronous motor

The operation principle of permanent magnet synchronous motor is to use the interaction between permanent magnet AC magnetic field to achieve energy conversion power output. The specific process is as follows:

1. Permanent magnet excitation: permanent magnet synchronous motor excitation mode using permanent magnet, can be divided into internal, external, internal external mixed magnetic circuit. Among them, the motor with built-in permanent magnet excitation is often used in low-power applications, the strength is low. A motor with external permanent magnet excitation can add additional magnets on the surface of the permanent magnet to improve the magnetic field strength of the permanent magnet. The motor with internal external hybrid magnetic circuit combines the advantages of the two methods, has the characteristics of high magnetic field strength small size.

2. Ac magnetic field: AC magnetic field is usually generated by three-phase AC power supply, controlled by frequency converter, generating frequency amplitude variable current, changing the direction size of the magnetic field rotation, so as to achieve speed regulation control.

3. Magnetic field interaction: Due to the interaction between the permanent magnet magnetic field the AC magnetic field, a certain magnetic flux is formed, so that the rotor (permanent magnet) is subjected to the tension thrust of the AC magnetic field during the rotation process, resulting in torque. When the rotor speed reaches the synchronous speed, the rotor the rotating magnetic field rotate simultaneously to achieve motor efficiency power output.

Second, the characteristics of permanent magnet synchronous motor

1. High efficiency: Because the permanent magnet is used as the excitation source, there is no need to consume electric energy to generate a magnetic field, compared with other motors, permanent magnet synchronous motors have higher efficiency lower energy consumption.

2. High torque density: permanent magnet synchronous motor has a larger torque density under the same power, can output higher torque, which is suitable for applications requiring large torque good dynamic response.

3. High speed: due to the high synchronous speed, the speed of permanent magnet synchronous motor is also relatively high, which can be applied to high-speed rotating mechanical equipment, such as wind turbines, centrifugal pumps, etc.

4. Small size: permanent magnet synchronous motor magnetic circuit is simple, permanent magnet in vitro embedded, small volume, can meet the small space installation requirements.

Third, the application of permanent magnet synchronous motor

1. Industrial field: permanent magnet synchronous motor is widely used in compressors, fans, pumps other mechanical equipment, suitable for industrial applications requiring high efficiency, high speed, large torque other characteristics.

2. Transportation field: permanent magnet synchronous motor can be applied to the drive system of electric vehicles, hybrid electric vehicles other transportation vehicles, with high efficiency, high speed, low noise other advantages.

3. Home appliances: permanent magnet synchronous motor can be applied to the drive system of household appliances such as vacuum cleaners, air conditioners, washing machines, has the advantages of low power consumption good stability.

In short, permanent magnet synchronous motor has the advantages of high efficiency, high torque density, small size, etc., which is suitable for a variety of applications. With the continuous development of technology, the performance application fields of permanent magnet synchronous motors will continue to expand.