DC and AC motors are widely used, and their basic principles of operation are the same. They both follow the law of electromagnetic induction and have their own advantages and disadvantages. After analysis, DC motors still have commutators, which is the main reason why the working methods of DC and AC motors are different. Let's take a look at the details again.
In order to ensure the stability and continuous rotation of the motor, the electromagnetic force induced in the rotor winding must be maintained in the same direction. If the rotor current is not reversed, the direction of electromagnetic force on the rotor will change, and the continuous rotation of the rotor cannot be guaranteed. In other words, as long as the direction of electromagnetic force in the rotor winding is the same, the rotor can continue to rotate.
2) AC motors do not work by reversing, but by changing the direction of the stator magnetic field, because in AC motors, the stator magnetic field is not fixed, but rotates according to a certain pattern, in order to ensure that the electromagnetic force direction of the rotor winding remains unchanged. As long as the stator coils are in phase, an AC motor will naturally generate a rotating magnetic field, causing the rotor to continuously rotate.
The working principle of DC and AC motors is the law of electromagnetic induction, but there are also differences between the two, which can be explained by different starting methods. The rotor rotation of a DC motor (the movement or force of the armature winding) is caused by the electromagnetic force acting on the excited armature winding in the magnetic field; Therefore, the prerequisite is that there must be current flow in the armature, so DC motors require armature current to start; The starting of an AC motor is achieved by injecting AC current into the stator, generating a rotating magnetic field. As it is in motion, as long as the rotor winding can form a closed circuit, it will generate current and induce electromagnetic force, causing the rotor to rotate.
The starting process of a DC motor is as follows: magnetic field+current in the armature winding → induced electromagnetic force in the winding → driving the rotor to rotate; The starting process of an AC motor is as follows: the stator is connected to three-phase AC power → the rotating magnetic field of the stator → causes the rotor winding to generate induced electromotive force in the rotating magnetic field → due to the formation of a closed circuit in the rotor winding (premise), there is current in the rotor winding → the rotor winding
The above are the differences and connections between DC motors and AC motors. If you would like to learn more, please contact us.
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