Learn about Three Phase Induction Motor with Block Diagram

Hey, in this article we are going to understand the working principle of a three-phase induction motor with a block diagram that will help you to quickly understand the concept. An electrical motor is a machine that converts electrical energy into mechanical energy in the form of rotational motion. There are a lot of types of electric motor works with different principles. The induction motor is that which works on the principle of electromagnetic induction. But remember that there are some differences between a single-phase and three-phase induction motor. Anyway, here we will discuss the three three-phase induction motor. 

Induction motors have a very simple design. They are easy to operate and control. To operate or rotate properly the three-phase power supply must be required. If any one of the phases is disconnected or not available the motor will not rotate and it will vibrate and maybe get damaged. An induction motor can be called a rotational transformer. The stator winding acts as the primary winding of a transformer and the rotor winding acts as the secondary winding of the transformer. The transformer has both static windings whereas the induction motor has static winding and rotating winding.

Block Diagram

Here, you can see the block diagram of the three-phase induction motor that describes the working principle.

Working Principle

The three-phase induction motor has a stator part and a rotor part. The stator part consists of a stator coil that is designed to operate with a three three-phase power supply. And the rotor part also consists of a rotor coil that is generally short-circuited. The rotor part is cylindrical in shape and it is free to rotate. When there is a torque applied to the rotor it will start rotating.

Now, when a three-phase power supply is applied to the stator coil it will produce a rotating magnetic field(RMF). This rotating magnetic field is produced due to the special type of coil arrangement of placement and the varying magnitude of the three-phase power supply at a certain frequency.

Now the magnetic flux from the rotating magnetic field will cut or link with the conductors of the rotor coil. We know that when a changing magnetic flux is cut or linked with a conductor an EMF will be induced. So, here also the same happens. An EMF is induced in the rotor coil due to the linkage of the rotating magnetic field.

We already know that the rotor coil is short-circuited. So a current will start flowing through the coil due to the induced EMF. Now, this current flow will create a magnetic flux in the rotor coil. Now there are two different magnetic fluxes. One is produced from the stator coil and another one is produced from the rotor coil. Now, these both fluxes will interact with each other and this interaction will create a torque on the rotor. As the rotor is free to rotate, it will start rotating. If the rotor coil is open-circuited the motor will not rotate as there is no current flow in the rotor so no magnetic flux.

Read Also: 

• What is Synchronous Speed and Asynchronous Speed in Induction Motor?
• Induction Motor Advantages and Disadvantages Explained
• Advantages of both STAR and DELTA connection in Induction Motor
• Why the Rotor of Slip Ring Induction Motor always Star Connected?
• Actual Difference Between Synchronous Motor and Induction Motor

Thank you for visiting the website. keep visiting for more updates.