How does a three phase induction motor develop torque?
Table of Contents
- 1 How does a three phase induction motor develop torque?
- 2 How does induction motor increase torque?
- 3 What is torque in induction motor?
- 4 What is the relation between torque and voltage in 3 phase induction motor?
- 5 How does the starting torque of the single phase induction motor can be increased?
- 6 Which type of induction motor has more starting torque?
- 7 What is the induction motor pull out torque?
- 8 When a 3-phase induction motor develops the starting torque equal to the maximum torque What is the slip and the rotor resistance?
How does a three phase induction motor develop torque?
Induction Motors An induction motor develops torque by inducing current to the rotor, which is proportional to the differential speed of the rotor and the rotating magnetic field in the stator.
How does induction motor increase torque?
There are three ways to improve the starting torque of Single phase induction Motor
- Internal Rotor Resistance. The across the line starting torque at low speed can be increased by increasing the rotor resistance.
- External Rotor Resistance.
- Variable Voltage/Frequency.
How torque is produced in a motor?
In magnetic motors, magnetic fields are formed in both the rotor and the stator. The product between these two fields gives rise to a force, and thus a torque on the motor shaft. One, or both, of these fields must change with the rotation of the rotor.
What is torque in induction motor?
Torque is the turning force through a radius – with the units Nm in the SI-system and the units lb ft in the imperial system. The torque developed by an asynchronous induction motor varies when the motor accelerates from zero to maximum operating speed.
What is the relation between torque and voltage in 3 phase induction motor?
Effect of Change of Supply Voltage on Starting Torque of 3-Phase Induction Motor. Hence, the starting torque is directly proportional to the square of the supply voltage. Therefore, the starting torque is very sensitive to changes in the value of the supply voltage.
What are the factors on which the torque of an induction motor depends?
1. The part of rotating magnetic field which reacts with rotor and is responsible for producing emf. 2. The magnitude of rotor current in running condition.
How does the starting torque of the single phase induction motor can be increased?
Starting torque of Induction motor can be improved by increasing the resistance of rotor but increasing the rotor resistance means compromise in efficiency of motor.
Which type of induction motor has more starting torque?
The capacitor-start motor develops a much higher starting torque, i.e. 3.0 to 4.5 times the full-load torque.To obtain a high starting torque, the value of the starting capacitor must be large, and the resistance of starting winding must be low.
How do you find the torque of an induction motor?
Torque of a three phase induction motor is proportional to flux per stator pole, rotor current and the power factor of the rotor. T ∝ ɸ I2 cosɸ2 OR T = k ɸ I2 cosɸ2 .
What is the induction motor pull out torque?
The breakdown or Pull Out Torque of an induction motor is shown by a blue line and it is the peak value achieved by the motor. In the case of stepper motor it is the highest torque a stepper motor can run at a given speed without losing steps.
When a 3-phase induction motor develops the starting torque equal to the maximum torque What is the slip and the rotor resistance?
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.