What is the principle and operation of the machine control circuit of an induction motor?

Induction motor, also known as ‘asynchronous motor’, is a device in which the rotor is placed in a rotating magnetic field, and under the action of the rotating magnetic field, a rotating torque is obtained, and thus the rotor rotates. The rotor is a rotating conductor, usually in the form of a squirrel cage. Invented by electrical engineer Nikola Tesla in 1887. The entry describes the concept, inventor, principle of operation, basic structure, mode of operation, braking method, asynchronous characteristics, specifications, and fault checking of induction motors. Induction motor is also called ‘asynchronous motor’, which means that the rotor is placed in the rotating magnetic field, and under the action of the rotating magnetic field, it obtains a rotating torque, and thus the rotor rotates.

The rotor is a rotating conductor, usually in the shape of a squirrel cage. The stator is the non-rotating part of the motor, whose main task is to generate a rotating magnetic field. The rotating magnetic field is not achieved mechanically. Instead, alternating current is passed through several pairs of electromagnets, so that the magnetic poles of the nature of the cycle change, so it is equivalent to a rotating magnetic field. This kind of motor is not like a DC motor with brushes or collector rings, according to the type of AC used in single-phase motors and three-phase motors, single-phase motors are used in such as washing machines, electric fans, etc.; three-phase motors are used as power equipment in factories.

The basic working principle of induction motor

Induction motor is a kind of motor that generates torque between rotor and stator by inducing electric current. The basic principle of operation is that according to the law of electromagnetic induction, an alternating magnetic field generates an induced current in the stator coil, which creates a rotating magnetic field in the rotor, thus generating torque and driving the motor to rotate.

An induction motor usually consists of two parts: the stator and the rotor. The stator is the stationary part of the motor and consists of the stator core, windings, and end caps. Three-phase staggered winding coils are distributed in the winding, and when three-phase power is connected to the winding, a rotating magnetic field is formed in the winding.

The rotor is the rotating part of the motor and usually consists of a rotor core and conductor bars. The conductor bars of the rotor are usually made of aluminium, copper and other good conductive materials and are fixed on the rotor core. When the rotating magnetic field passes through the rotor conductor bars, the induced electromotive force will generate a current inside the conductor bars, and the rotor will be subjected to a certain amount of torque because the current inside the conductor bars is subjected to electromagnetic force.

Depending on how the magnetic field is generated, induction motors can be classified into two types, which are asynchronous motors and synchronous motors. An asynchronous motor is the most common type of induction motor, in which the rotor rotates at a slightly lower speed than the magnetic field, called slip. Synchronous motors, on the other hand, are motors whose rotational speed is exactly the same as the rotational speed of the magnetic field.

In summary, the basic operating principle of an induction motor is to form a rotating magnetic field in the stator coil through the principle of electromagnetic induction, thereby generating a rotating magnetic field within the rotor, which drives the motor to rotate through the torque generated by the induced current. This type of motor has the advantages of simple structure, high reliability and stable operation, and is one of the main types of motors widely used in various industrial and civil fields.

Induction motor is a type of motor that generates torque between the rotor and stator by induced current. The basic working principle is to generate an induction current in the stator coil through an alternating magnetic field according to the law of electromagnetic induction, which causes a rotating magnetic field in the rotor, thus generating a torque and driving the motor to rotate.