Single Phase Induction Motor Working Principle and Other Informations

The main purpose of electrical motor is to convert electrical power in to mechnical power. As we discuss in our earlier articles the electrical motors can mainly divide in to

Alternative current motors (AC)
Direct Current Motors (DC)

Today we are plan to disucss one type of the electrical motor which fall under AC motor category. Induction motor is one of the most famous electrical motor in industy. The motor can further classified in to single phase and three phase induction motor . The classification are manly beacuse of its supply voltage levels

single phase induction motor construction

Single phase induction motors are one of the most powerful and used electrical motor type . The main components of the single phase induction motors are

Rotor (rotating part of the motor)
Stator windings (stationary part inside motor)

This stationary winding consist two parts such as auxiliary windings and main winding.

Double revolving field theory is the main single phase induction motor working principle.

Single Phase Induction Motor Working Principle (Double revolving field theory)

Double revolving field theory is the single phase induction motor working principle and it also help the operation of the single phase induction motor.

The fluctuating field of the stator is equal to the sum of the two rotating magnetic field. Since the magnetic field is varying the electricity induce to the rotor bars due to the electromagnetic induction.

Main Purpose of the Auxiliary Winding of the Induction Motor

Auxiliary winding is perpendicular to the main windings. Capacitor is connect to the auxiliary winding of the single phase induction motor. The main purpose of the auxiliary winding with capacitor to use to starting purpose of the induction motor. Auxiliary winding also produce two rotating magnetic field.

So one of them will cancel the rotating magnetic field of the stator winding. The resultant will be a single magnetic field which revolve under the specific field. This kind of magnetic field can generate starting torque to the motor.

Why this motor is not self starting

The main problem of this motor is, its not self starting motor. The reason for that is the foraward and backward flux of the motor are same and in opposite direction. So induction motor is not a self starting motor.

Due to this problem seperate auxulary winding and capacitor is connect to this motor for strating purposes. According to arrangement of capacitor and auxulairy winding , induction motors can further classified.

Types of Single Phase Induction Motor

There are several types of induction motors available in the industry such as.

Split Phase Induction Motor
Capacitor Start Induction Motor
Capacitor-start and capacitor–run induction motor
Permanent split capacitor (PSC) induction motor

The operation of this mentioned type of single phase induction motors are different. We are plan to discuss the operations and featurs of this motor in our future articles.

Single phase induction motor consist auxiliary winding work as self starting motor. After the motor got specific speed the operation of the auxiliary winding will cut down. This cutting action will do by a simple centrifugal switch.