Introduction to various types of motors
(1) DC motor
Advantages: large driving force during starting and acceleration, simple speed control, and mature technology;
Disadvantages: armature current is introduced by brushes and commutator, sparks are generated during commutation, commutator is easy to burn, brushes are easy to wear, need to be replaced frequently, and maintenance workload is large; there is friction loss in the contact part, which not only reduces the efficiency of the motor but also limits the working speed of the motor.
Newly developed electric vehicles do not use DC motors.
(2) Brushless DC motor
A Brushless DC motor is a high-performance motor. It has many advantages of AC motors such as simple structure, reliable operation and easy maintenance, and high operating efficiency, no excitation loss, low operating cost and good speed regulation performance. Therefore, its application in electric vehicles is increasing day by day.
(3) Asynchronous motor
Asynchronous motor is widely used in electric vehicles. This is because when asynchronous motors use variable frequency speed regulation, mechanical transmission can be eliminated, step-less speed change can be achieved, and transmission efficiency is greatly improved. Asynchronous motors can easily achieve forward and reverse rotation, and regenerative braking energy recovery is also simpler. When using a cage rotor, the asynchronous motor also has the advantages of simple structure, durability, low price, reliable operation, high efficiency, and maintenance-free.
(4) Permanent magnet synchronous motor
The permanent magnet synchronous motor is similar to the brushless DC motor in structure, but it uses a sine wave drive. Therefore, while having the advantages of a brushless DC motor, it also has the characteristics of low noise, small size, high power density, small moment of inertia, small pulsating torque, and high control accuracy. It is particularly suitable for hybrid electric vehicle motor drive systems to achieve the purpose of reducing system volume, improving vehicle acceleration performance and driving stability. Therefore, permanent magnet synchronous motors have received attention from major automobile manufacturers around the world.
(5) Switched reluctance motor
The switched reluctance motor is a new type of motor. Due to its simple structure, ruggedness, reliable operation and high efficiency, its speed control system has better operating performance and economic indicators than ordinary AC speed control systems. It has great potential and is recognized as a very promising electric vehicle drive motor.
High-density, high-efficiency, lightweight, low-cost, wide speed regulation traction motor drive systems have become the main focus of research and development in various countries. Such as permanent magnet switched reluctance motor, rotor pole split hybrid excitation structure synchronous motor, permanent magnet brushless AC motor, etc.
