Hi friends do you know what is hunting in this post we will discuss about all concept related to hunting

What is hunting.
cause of hunting.
Effect of hunting.
Prevention of hunting in synchronous motor

What is hunting ? how can we define it ?

Hunting is defined as oscillation of rotor about its equilibrium position.

Synchronous motor always run at constant speed. When the load on motor increased the rotor falls back in phase by an angle alpha Known as load Angle , in order to meet additional demand. As the load is suddenly increased this angle also increases so as to produce more torque to meet increase load when the load is suddenly thrown off ,the rotor poles pulled advances into exact position but in the process the rotor overshoots and hence is again pulled back and so on. Thus, the rotor starts oscillating like pendulum about its new position of equilibrium which is known as hunting the hunting sometimes called phase swinging.

Cause of hunting

The following are main cause of hunting
The sudden change of load.
  • Sudden changes the field excitation current
  • Faults appearing in the system which generator supplies.

Now we discuss 

Effect of hunting
  • It leads to loss of synchronism.
  • There may be large stress developing in rotor shaft.
  • The loss of machine increases and there is a rise in temperature of machine.

Prevention of hunting
There are various method to prevent the motor from hunting but I am explain two main method.

  • Damper winding
  • Use of flywheel 
Damper winding

Hunting can be prevented by providing damper winding . Damper winding is also known as squirrel cage winding the damper winding consists of number of copper bars embedded in the faces of field poles of synchronous motor. Copper be also 
certificate to the both ends by copper ring.