Early Tesla Model S and Model X used asynchronous induction motors. With the upgrades, Tesla brought permanent magnet synchronous motors to Model S and Model X models for the first time in 2019. In Tesla’s latest Model S/Model X Plaid version, Tesla uses three permanent magnet synchronous motors to drive the vehicle, enabling the Plaid version of the Model S/Model X to accelerate from 0 to 100 kilometers/hour in an astonishing 2.1/2.6 seconds. Two other popular Tesla models, the Model 3 and Model Y, also use permanent magnet synchronous motors. The following article will discuss permanent magnet synchronous motors and asynchronous induction motors, which are mainly used in electric vehicles.
The biggest difference between a permanent magnet synchronous motor and an asynchronous induction motor is the rotor. The rotor magnetic field of a permanent magnet synchronous motor is generated by permanent magnets, while the rotor magnetic field of an asynchronous induction motor is generated by the induced current in the rotor conductors generated by the speed difference of the stator magnetic field relative to the rotor. This difference means that the torque density of the induction asynchronous motor is not as good as that of the permanent magnet synchronous motor, and the copper loss will be higher than that of the permanent magnet synchronous motor.
In short, compared with asynchronous induction motors, permanent magnet synchronous motors have higher power density, better energy conversion efficiency, and lower energy consumption. At the same time, permanent magnet synchronous motors are more expensive due to the addition of permanent magnets. It should be noted that the operating temperature of Neodymium magnets should not be exceeded. Once the operating temperature is exceeded, there is a risk of demagnetization. (Considering the risk of high temperature demagnetization and high temperature performance, some motors also choose high temperature resistant Samarium Cobalt magnets as permanent magnets)
Under the general trend of low-carbon and energy-saving, permanent magnet motors are increasingly becoming a good choice.