The torque slip curve for an induction motor gives us the information about the variation of torque with the slip. The slip is defined as the ratio of difference of synchronous speed and actual rotor speed to the synchronous speed of the machine.

## What is torque speed characteristic of induction motor?

Torque Speed Characteristic is the curve plotted between the torque and the speed of the induction motor. As we have already discussed the torque of the induction motor in the topic Torque Equation of an Induction motor. The equation of the torque is given as shown below.

## What is normal slip of an induction motor?

Because of this speed difference, the motor rotates at a speed slightly slower than the synchronous speed. Slip is normally expressed in percentage. Slip of a power induction motor is 2 to 3% when the motor is operated under the rated load.

## Why the torque characteristics are straight line?

After magnetic saturation of the field poles, flux ɸ is independent of armature current Ia. Therefore, the torque varies proportionally to Ia only, T ∝ Ia. Therefore, after magnetic saturation, Ta-Ia curve becomes a straight line. The shaft torque (Tsh) is less than armature torque (Ta) due to stray losses.

## At what slip does the maximum torque occur?

So, when slip s = R2 / X2, the torque will be maximum and this slip is called maximum slip Sm and it is defined as the ratio of rotor resistance to that of rotor reactance. NOTE: At starting S = 1, so the maximum starting torque occur when rotor resistance is equal to rotor reactance.

## What is the relationship between torque and speed?

Torque is inversely proportional to speed. Thus, when speed increases, torque will decrease.

## What is Torque slip?

The torque slip curve for an induction motor gives us the information about the variation of torque with the slip. The slip is defined as the ratio of difference of synchronous speed and actual rotor speed to the synchronous speed of the machine.

## What is slip in 3 phase induction?

This speed difference is called slip. Therefore, the difference between the synchronous speed Ns of the rotating stator field and the actual rotor speed N is called slip. The slip increase with load and is necessary for torque production. Slip speed is equal to the difference between rotor speed and synchronous speed.

## How does an induction motor start?

When the supply is connected to the stator of a three-phase induction motor, a rotating magnetic field is produced, and the rotor starts rotating and the induction motor starts. … At the time of starting, the motor slip is unity, and the starting current is very large.

## What happens if the slip of induction motor is one?

Slip = 1, means that rotor is stationary. Negative value of slip in induction motor can be achieved when the rotor speed is more than the synchronously rotating magnetic flux.

## What is motor torque formula?

As you see this equation torque is the product of the force and the distance between the force and the center of rotation. For example, if you want to hold the force acting on the end of pulley, T = F x r.

## What is relation between torque and current?

Electrical motor torque is proportional to the product of magnetic flux and the armature current. Mechanical or load torque is proportional to the product of force and distance. Motor current varies in relation to the amount of load torque applied.

## Is torque directly proportional to RPM?

The relation between torque and speed are inversely proportional to each other. The torque of a rotating object can be mathematically written as the ratio of power and angular velocity.

## How do you get maximum torque?

Note that the torque is maximum when the angle is 90 degrees. A practical way to calculate the magnitude of the torque is to first determine the lever arm and then multiply it times the applied force. The lever arm is the perpendicular distance from the axis of rotation to the line of action of the force.

## What is maximum torque in induction motor?

The developed torque is maximum when the rotor resistance per phase is equal to the rotor reactance per phase under running conditions. By putting the value of sX20 = R2 in the equation (1) we get the equation for maximum torque.

## What is the maximum torque?

Torque is defined as τ = rF sin θ, where F is the force, r is the distance from the pivot that the force is applied, and θ is the angle between r and F. … (b) The maximum torque occurs when θ is a right angle and sin θ = 1.