For a practical synchronous motor the pull out torque will occur when the torque angle is nearly equal to
A. 0°.
B. 30°.
C. 45°.
D. 75°.
Show Answer
Answer: D
Share your understanding of this question with the correct explanation.
The answer is D. 75°.
The pull-out torque of a synchronous motor is the maximum torque that the motor can produce before it slips out of synchronism. The pull-out torque occurs when the torque angle is nearly equal to 75°.
The torque angle is the angle between the rotor magnetic field and the stator magnetic field. When the torque angle is 0°, the rotor and stator magnetic fields are aligned, and the motor runs at synchronous speed. As the torque angle increases, the rotor lags behind the stator, and the motor speed decreases. When the torque angle reaches 90°, the rotor is stationary and the motor has stalled.
The pull-out torque is determined by the design of the motor, including the number of poles, the rotor and stator materials, and the windings. The pull-out torque is typically 1.5 to 2 times the rated torque of the motor.
Here are some additional details about pull-out torque:
- It is the maximum torque that a synchronous motor can produce before it slips out of synchronism.
- It occurs when the torque angle is nearly equal to 75°.
- It is determined by the design of the motor.
- It is typically 1.5 to 2 times the rated torque of the motor.
Pull-out torque is an important factor to consider when selecting a synchronous motor for a particular application. The motor must be able to produce the required torque at the desired speed without stalling.