Induction is the most popular type of machine in the electrical industry. Given below are the 7 Basic concepts you need to know about Induction Motors.
What Induction Motor is named so?
The rotor current in electrical machines is often induced by physically connecting wires. However, in an induction motor, the rotor voltage is induced instead of physically connecting cables.
How many types of Induction Motors are there
Induction motors are often classified into two types:
- Cage rotor
- Wound rotor
This classification is done on the basis of rotor design.
What is synchronous speed
The speed of rotation of the magnetic field is known as synchronous speed. The synchronous speed of motor depends on its frequency, pole number a constant 120.
Mathematically,
Synchronous Speed = (120 * f) / P
What is rotor slip
It is a relative ration of the mechanical speed of shaft with respect to the speed of magnetic fields.
Mathematically,
Slip = 1 – (ηm/ηsync)
where,
ηm = Mechanical speed of shaft of motor
ηsync = Speed of magnetic fields
What is Design class in Induction motors
During production of induction motors, the different designs of torque-speed curves of motor can be produced by varying rotor characteristics. These designs are technically referred as design classes. Today induction motors are available in Design Class A, B, C, and D
What is variable frequency drive
A variable frequency drive is a type of adjustable-speed drive which is used in electromechanical drives to control the speed and torque of motor by varying input frequency and voltage.
What is Induction generator and its limits of working
If an induction motor is forced to drive at a speed greater than synchronous speed, its inducted torque reverses direction and will behave as a generator.