## Harmonics in an Induction Motor

Space harmonics fluxes are produced by the windings, slotting, magnetic saturation, inequalities in the air gap length. These harmonic fluxes induce voltages and circulate harmonic currents in the rotor windings. The interaction between the harmonic currents generated in the rotor and the harmonic fluxes results in the Harmonic torques, vibrations, and the noise. The air …

## Stator Voltage Control of an Induction Motor

Stator Voltage Control is a method used to control the speed of an Induction Motor. The speed of a three-phase induction motor can be varied by varying the supply voltage. As we already know that the torque developed is proportional to the square of the supply voltage and the slip at the maximum torque is …

## Difference Between Star and Delta Connection

Difference between star and delta connection are explained considering various factors like the basic definition of the connections, the existence of a neutral point, the connection of the terminals, the relation between line current and phase current and also between line voltage and phase voltage, speed, its insulation level, number of turns, type of system …

## Slip Energy Recovery of an Induction Motor

Slip Energy Recovery is one of the methods of controlling the speed of an Induction motor. This method is also known as Static Scherbius Drive. In the rotor resistance control method, the slip power in the rotor circuit is wasted as I2R losses during the low-speed operation. The efficiency is also reduced. The slip power …

## Circle Diagram of an Induction Motor

The Circle Diagram of an Induction motor is very useful to study its performance under all operating conditions. The construction of the circle diagram is based on the approximate equivalent circuit shown below. It is the diagrammatic representation of the performance of the induction motor. The circle diagram provides information about the power output, losses, …

## Rotor Resistance Control of an Induction Motor

Rotor Resistance Control is also one of the methods by which we can control the speed of the Induction motor. The speed of the wound induction motor can be controlled by connecting an external resistance in the rotor circuit through slip rings. This method is not applicable to cage rotor induction motors. As we know …

## Speed Control of Induction Motor by Variable Frequency Control

Variable Frequency Control is a method that is used to control the speed of an induction motor. The synchronous speed and therefore, the speed of the motor can be controlled by varying the supply frequency. The synchronous speed of an induction motor is given by the relation shown below: The EMF induced in the stator …

## Speed Control of an Induction Motor

There is a various method of speed control of an Induction Motor. The rotor speed of an induction motor is given by the equation shown below. From equation (1) it is clear that the motor speed can be changed by a change in frequency f, a number of poles P, and slip s. Any one or …

## Pole Changing Method

Pole Changing Method is one of the main methods of the speed control of an induction motor. This method of controlling the speed by pole changing is used mainly for cage motor only because the cage rotor automatically develops a number of poles, which is equal to the poles of the stator winding. The number …

## Double Cage Rotor of an Induction Motor

A Double Cage Induction motor is that type of motor in which a double cage or two rotor windings or cages are used. This arrangement is used for obtaining high starting torque at a low value of starting current. The stator of a double cage rotor of an induction motor is the same as that …