What kinds of new energy vehicle motors are available in the era of new energy vehicles?

　　The era of new energy vehicles has come and gone, and its popularity has soared, so today I will give you a brief introduction to the types of motors for new energy vehicles and their advantages and disadvantages.
　　The first type, DC motor.
　　A DC motor allows DC current from the car battery to be transmitted to the rotor winding through spring-loaded carbon or lead "brushes", which provide energy for the rotating contacts connected to the wire winding. Each time a few degrees of rotation are made, the brushes power a new set of contacts. When the car's motor shaft rotates, it successively reverses the polarity of the electromagnets on the rotor.
　　The housing around the rotor's electromagnetic windings has permanent magnets. The advantages are lower cost to begin with, higher reliability, and easy control of the motor. Changing the voltage can regulate the speed of the motor and can also change the current, which in turn controls its torque. The disadvantages cover the lower service life and also the cost of maintaining the brushes as well as the contacts. Hence this type of motor is rarely used in transport except in some Indian Railway locomotives.
　　The second type, brushless DC motor.
　　This type of motor produces a rotating magnetic field by transferring permanent magnets on top of the rotor, then placing an electromagnet on top of the stator (housing), and also using an external motor controller to switch the various excitation windings, alternately, from the positive to the negative winding, eliminating the brushes and their maintenance.
　　Advantages are longer service life, high efficiency as well as low maintenance costs. The disadvantages are higher initial cost, more complex motor speed controllers, and generally three Hall effect sensors are required to correctly determine the phase of the stator winding current. Switching of the stator windings results in torque pulsations, with the delivered torque increasing and decreasing periodically. This type of motor is very popular in the small vehicle market, such as e-bikes and scooters, and is used in some auxiliary vehicle applications, such as electric power steering assistance.
　　The third type is the permanent magnet synchronous motor.
　　Physically, BLDC and PMSM motors look the same. Both have permanent magnets in the rotor and excitation windings in the stator. The difference is that instead of using DC current as well as periodically switching various windings on as well as off, which in turn rotates the permanent magnets, the PMSM operates on a continuous sinusoidal AC current. This means that there are no torque fluctuations and only a Hall effect sensor is required to determine rotor speed and position, making it more efficient.
　　Advantages are their power density and strong starting torque. The disadvantage is that a reverse electromotive force is generated when the motor is not supplied at high speeds, which causes resistance and heat to demagnetise the motor. These motors are used in part in automotive power steering and braking systems, and have become the motor design of choice for most battery electric and hybrid vehicles today.