What is the difference between permanent magnet synchronous motor and asynchronous motor?

更新日期:2020-07-29
摘要:Permanent magnet motor, as the name suggests, is: a motor with a magnetic core inside. The biggest d...
What is the difference between permanent magnet synchronous motor and asynchronous motor?

 

Permanent magnet motor, as the name suggests, is: a motor with a magnetic core inside. The biggest difference between it and asynchronous motor lies in the unique structure of the rotor. High-quality permanent magnet poles are placed on the rotor.

 

Its characteristics are: large power per unit weight, large overload current, but its low speed. Suitable for low speed and high torque, most two-wheel drive vehicles use permanent magnet motors. Moreover, because of the magnetic core, the cost of the permanent magnet motor is higher.

Asynchronous motors have a similar structure to permanent magnet motors, except that they do not have a magnetic core. (Remember to cut the magnetic field lines in middle school textbooks to generate current?) Its characteristics are: it has no magnetic field when it is not energized, so it consumes a lot of power Only a large amount of electricity can generate a magnetic field. Its maximum speed can reach 15,000 rpm, it is a high-speed motor, high speed produces high power. However, it has low cost, strong overload capacity, and is convenient to use, install and maintain.

 

The dynamic performance of electric vehicles is reflected in the maximum speed and the acceleration time of 100 kilometers. It is determined by the output power of the motor, and the output power of the motor is determined by the speed and torque. Tesla uses an AC asynchronous motor that can pass ultra-high voltage And weak magnetic drive to achieve high speed of more than 10,000 rpm. At the same time, by driving a motor control system such as an inverter, the motor can be operated at a high torque of 600Nm, thereby ensuring that the Tesla motor outputs high power, thereby improving Tesla's power Performance, which is why Tesla loves AC asynchronous motors.

 

Although the cost of asynchronous motor is low, it consumes a lot of electricity, so the energy consumption is high.