Trying to figure out the structure and working principle of a three-phase induction motor? You’ve come to the right place! In this blog post, we’ll take a deep dive into exactly how this type of motor works, as well as why it is one of the most popular motors used today. We will also discuss the differences between single-phase and three-phase induction motors, their design features, and their applications in various industries. By the end of this post, you should have a better understanding of how three-phase induction motors work and why they are so important in modern industry.

Overview Of Three-Phase Phase Induction Motor

An induction motor is a rotating electric machine in which the stator (stationary part) windings create a rotating magnetic field that induces torque in the rotor (rotating part). The three-phase induction motor is the most widely used electric motor.
The three-phase induction motor has a simple structure and is easy to operate. It does not require brushes or commutators, and therefore has low maintenance costs. However, it is not suitable for high-speed applications because of the need for a slip ring and brush assembly.
The working principle of the three-phase induction motor is based on the interaction between the stator's rotating magnetic field and the rotor's conductor. When the stator's rotating magnetic field interacts with the rotor's conductor, an induced current is generated in the conductor. This induced current interacts with the stator's magnetic field to create a torque that rotates the rotor.

Structure Of Three-Phase Induction Motor

The three-phase induction motor is the most widely used electrical motor. Almost 80% of industrial motors are three-phase induction motors because of their simple and rugged construction, lower cost, good running characteristics, self-starting capability, etc.
The three-phase induction motor has a stator and a rotor. The stator is the stationary part of the motor and consists of a set of three windings that are spaced 120 degrees apart in the form of a squirrel cage. The rotor is the rotating part of the motor and consists of a winding that is connected to an external power source (usually through slip rings).
When the stator windings are energized with alternating current (AC), a magnetic field is generated that rotates at synchronous speed. The rotating magnetic field induces a current in the rotor winding, which in turn creates a magnetic field. The interaction between the stator's rotating magnetic field and the rotor's magnetic field causes the rotor to rotate at a speed slightly slower than synchronous speed.

Working Principle Of Three-Phase Induction Motor

The principle of operation of an induction motor is based on the phenomenon of electromagnetic induction. When a three-phase AC supply is given to the stator winding, a rotating magnetic field is set up. This rotating magnetic field induces a current in the rotor winding which in turn produces a rotating magnetic field. The interaction between these two fields sets up a torque that rotates the rotor.
The stator of a three-phase induction motor consists of three coils (called stator windings) placed at 120° to each other in the internal space of the stator core. The three-phase supply is given to these coils through slip rings and brushes. The rotor consists of a winding (called rotor winding) wound on a laminated iron core. The rotor winding is connected to a slip ring through which a DC supply is given.