Types of AC Motors

Types of AC Motors

In the modern era, electricity and electrical equipments play a vital role. Wihtout them, it is hard to imagine life. One such electrical devices that resulted in giant leap for mankind is the motor. Among motors, the usage of AC motors is much prevalent than DC motors. Various types of AC motors are used for variety of applications in everyday life. AC motors are classified into different types depending on it specifications. The classification of AC motors is explained in the next section.

Classification of AC motors

The AC motor classification based on several parameters are given below in detail:

AC Motors classification based on Principle of Operation:

  • Synchronous Motors
    1. Plain
    2. Super
  • Asynchronous Motors
    1. Induction Motors
    2. Squirrel Cage
    3. Slip-Ring
  • Commutator Motors
    1. Series
    2. Compensated
    3. Shunt
    4. Repulsion
    5. Repulsion induction
    6. Repulsion-start induction

AC Motors classification based on Type of Current

  • Single Phase
  • Three Phase

AC Motors classification based on Speed of Operation

  • Constant Speed
  • Variable Speed
  • Adjustable Speed

AC Motors classification based on Structural Features:

  • Open
  • Closed
  • Semi-enclosed
  • Ventilated
  • Pipe-ventilated
  • Riveted Frame-eye

But, AC Motors are clasified into two types as:

  • Synchronous Motor
  • Induction Motors

A flowchart for the classification of AC motor is given below:

Classification of AC Motors

A description of each type of AC motor is given below:

Synchronous Motors

The rotational speed of the stator current is equal to the rotational speed of the rotor. They don’t have slip with respect to stator current.

Asynchronous Motors

These motors slip with respect to stator current field. They are used in different varieties of pumps etc.

Single Phase and Three Phase Motors

Single phase motors are used in domestic appliances. Three phase motors are used in high power appliances.

Constant,Variable & Adjustable Speed Motors

This types of AC motors are flexible for controlling speed. Constant speed is performed in air compressors. Cooling pumps can function in variable speeds by making a switch in the number of poles used. Changing the number of poles results in speed change. Motor’s speed can also be changed accordingly with some electronic arrangements which is ideal for ship’s cargo pump where the discharge rate needs to be lowered as per the requirement of the tunnels.

Varied Structure Motors

Depending upon the industrial requirements, motors have variety of outer cage arrangements. For example, motors which are used in oil and gas terminals should have safe enclosed casing in order to prevent from sparks produced in the motor to cause fire outside of it.

These were some types of AC motors, if you wish to know more, download BYJU’S The Learning App


Practise This Question

A 150 m long train is moving with a uniform velocity of 45 km/h. The time taken by the train to cross a bridge of length 850 meters is