What is the difference between the motor of the car company? What is the difference between the permanent magnet synchronization and the AC asynchronous motor? What are the advantages and disadvantages?



According to the 2021 global new energy brand sales data released by Cleantechnica’s website, the cumulative sales of global new energy models in 2021 were nearly 6.5 million, an increase of 108%over the same period last year. Tesla led with nearly one million data. BYD ranked second with sales of 593,900 units, an increase of more than 220%year -on -year, and the global market share reached 9.1%.

At present, the most important new energy model must be the three -electric system, and it is obviously very important as a motor with a vehicle. It is represented by Tesla and BYD championship runners. Different. European and American car companies are mainly equipped with AC asynchronous motors, representing Tesla, Mercedes, etc.; Chinese car companies are mainly equipped with permanent magnet synchronous motors. Representative car companies include BYD and ideal cars. What are the differences between the two types of motors, and the car companies have different choices?

The internal structure of the asynchronous sensing motor and permanent magnet synchronous motor can clearly distinguish between two motor technology. The rotor of the permanent magnet synchronous motor is permanent magnet, referred to as PMSM in English. The rotor of the asynchronous sensing motor is not a magnet, but a closed coil, which is commonly known as the mouse cage structure. In terms of principle, we will not explain in -depth.

In summary of their respective characteristics:


Advantages of synchronous motor: 1. Rotor non -motivation magnetic winding, so no rotor copper consumption, so high efficiency; 2. High -performance permanent magnet materials provide incentives, the given power is small, and the volume can be reduced; 3. The rotor rotation is small, so Good dynamic performance; 4. Great power and torque output at low efficiency.


Synchronous motor disadvantages: high cost, low reliability, complex processing process, poor mechanical strength.


Advantages of asynchronous motor: 1. The problem of high -temperature magnetic degeneration of non -permanent magnetism can extend peak power, rated power, and peak power. 2. The electrical characteristics are less affected by the environment; 3. It has the adjustment of high torque and high -speed torque adjustment;

The disadvantage of asynchronous motor: The rotor magnetic field comes from the stator excitation, there is copper consumption, and the energy conversion rate is lower than the permanent magnet synchronous motor.

Their advantages and disadvantages of the motor carried by new energy models are:

The advantages of AC asynchronous motor: good reliability; good high speed performance; easy control. Disadvantages: low power density (larger volume at the same power level); low energy conversion efficiency (85%-90%); high energy consumption.


The advantages of permanent magnet synchronous motor: high power density; high energy conversion efficiency (90%-95%); low energy consumption. Disadvantages: Due to the addition of permanent magnets, the cost is increased; the permanent magnet has the risk of degeneration in high temperature and vibration environment.


Select the characteristics of the model of AC asynchronous motor:


The models that choose to AC asynchronous motor will tend to prioritize performance. Using the performance output and efficiency advantages of AC asynchronous motors at high speed, the representative model is the early Model S. Main features: When cars are driving at high speed, they can maintain high -speed operation and efficient power use efficiency, while maintaining maximum power output, reducing energy consumption.

The characteristics of the model of the permanent magnet synchronous motor:

The models that choose permanent magnet synchronous motors tend to take the priority of energy consumption. The performance output and efficient operation of the permanent magnet synchronous motor in the low -speed stage are suitable for small and medium -sized vehicles. The characteristic is that the size and light weight can increase the battery life. At the same time, it has good speed adjustment performance. It can maintain high efficiency when facing repeated start -stop and acceleration.

The asynchronous sensing motors and permanent magnet synchronous motors have their own advantages, so some OEMs consider matching the characteristics of the two motors. For example, the front axis is equipped with a low -speed and high -efficiency permanent magnet synchronous motor, and the rear axis is equipped with an AC asynchronous motor that is biased towards high -speed performance. The two are closely coordinated and the efficiency is higher.

Although the power system barriers of electric vehicles do not have high fuel vehicles and relatively single types, these two motors need to be controlled with very powerful electrical control systems in order to achieve excellent power consumption and vehicle linear acceleration. Electric control can be used, and electronic control can be used. Behind the system requires enough battery power, so the three -electric level of electric vehicles is the essence of a pure tram.


The permanent magnet synchronization and AC asynchronous motor are different from the principle, so the characteristics of the two are different. The reliability of the AC asynchronous motor, good high speed performance, and cost -controlled cost. Permanent magnet synchronous motor has high power density, high energy conversion efficiency, and low energy consumption. At present, the permanent magnet synchronous motor will still be more suitable for subsequent development, and the combination of the two is also a good choice.