Hunting in a synchronous cannot be due to
A. windage friction.
B. variable frequency.
C. variable supply voltage.
D. variable load.
Show Answer
Answer: C
Share your understanding of this question with the correct explanation.
The answer is C. variable supply voltage.
Hunting is a phenomenon that occurs in synchronous motors when there is a sudden change in load. The rotor of the motor will begin to oscillate around its synchronous speed. This oscillation can cause the motor to lose synchronism and stall.
Variable supply voltage can cause hunting in synchronous motors, but it is not the only cause. Other causes of hunting include:
- Variable load
- Windage friction
- Mechanical defects
Variable supply voltage can cause hunting because it can cause the motor to operate at a different speed than its synchronous speed. This can cause the rotor to lag behind the stator, which can lead to hunting.
To prevent hunting, the supply voltage can be kept constant. Other methods of preventing hunting include:
- Increasing the field excitation of the motor
- Using damper bars
- Using a soft starter
- Using a variable frequency drive (VFD)
Increasing the field excitation of the motor is the most effective way to prevent hunting. Damper bars can also help to prevent hunting, but they are not as effective as increasing the field excitation.
A soft starter or a VFD can also be used to prevent hunting. These devices can gradually increase the speed of the motor, which helps to prevent the sudden changes in load that can cause hunting.