With the popularity of electric cars and hybrid vehicles, the selection of core components gradually get people’s concern. Among them, the motor, core part of power unit, has two mainstream choices: dc motor and ac motor.
This article mainly introduce the ac motor.
The ac motor is a kind of motor, which can achieve interchange of alternating current electrical power and mechanical energy.
The representative of ac motors: three-phase four-class ac motor (asynchronous motors / induction motors).
The three-phase four-class ac motor is also called asynchronous motor, which can produce a rotating magnetic field to cut the rotor windings and produce electromagnetic torque when the three-phase alternating current pass through the three-phase windings of the stator. The existence of speed difference is a necessary condition for the rotation of the asynchronous motor, which is the cause resulting in name of asynchronous.
The asynchronous motors have the following characteristics:
1, simple structure, high reliability.
2, easy to manufacture and low cost.
3, easy to make high-speed, high-voltage, high-current, high-capacity motor.
4, obvious kinetic energy recovery effect.
Applications: Tesla Roadster
However, despite the rapid development of AC motor technology, the ac motor also has its own insurmountable defect. The biggest problem of asynchronous motors applied in electric vehicles is that the starting torque is too small, which has a certain requirement for the output power of the battery. The efficiency of ac asynchronous motor is relatively low, and the energy feedback performance and speed performance is also relatively poor. To compensate for these shortcomings, the AC electric car motor typically is equipped with a gearbox.