Introduction and comparison of different types of motors
A motor, as its name suggests, is a device for converting electrical energy and mechanical energy. Any motor can be operated either as a motoring or as a generator. It does not generate energy itself. It only converts the electromechanical energy, but the loss during the conversion is converted into heat, so any motor Design includes electromagnetic design, mechanical design and thermal design. Everyone pays attention to electrical power, mechanical power, loss and efficiency, temperature and other performance parameters.
Depending on the structure and application, there are many types of motors. However, the main applications for current automotive drives are permanent magnet synchronous motors, asynchronous motors (induction motors), switched reluctance motors, electric excitation motors, and DC motors. At this point, everyone can't help but pay attention to these motors are different, what are the advantages and disadvantages? We may wish to make a simple science here.
DC
DC motor is the oldest invention in the motor family. Its inventor is Faraday, which is familiar to everyone. The traditional DC motor is mainly composed of the armature winding on the rotor, the excitation winding on the stator, the stator core, the base and the brush-changer. The actuator is constructed such that the field winding provides an excitation field and the armature winding provides a current that produces torque.
As mentioned above, DC motors have excitation windings and armature windings. By controlling the current of the excitation windings, the magnitude of the magnetic field can be controlled. By controlling the current of the armature windings, the torque can be adjusted. Therefore, the biggest advantage of the DC motor is that the control performance is good. The output speed and torque of the motor can be adjusted almost linearly by means of an external variable resistor.
However, due to the presence of the brush, the reliability is low, the maintenance cost is high, and the additional loss due to the brush contact resistance and the external resistance is large, and the motor efficiency is relatively low. At present, the newly developed electric vehicles basically no longer use brushed DC motors, and are generally only used in window lifts, driving wipers and the like, and the use of electronic commutators to replace the brush commutator.
