How damper winding in synchronous motor suppress Hunting?

Answer Posted / iamdon

In synchronous machines, the damper winding is placed on
pole face of rotor which is short circuited at end.

When load on machine is suddenly changed, the rotor starts
oscillating (due to its inertia )about the new equilibrium
point.However the oscillation finally dies out because of
presence of damper winding.The oscillation is called
hunting.

During hunting,there is a relative motion between rotor
(damper winding)and synchronously rotating magnetic field.
So emf induces in the damper winding as per Faraday's law
and current flows in accordance with Lenz's law as long as
the relative motion exists.As we know,the effect will
always oppose the cause.Here effect is induced current in
damper winding and cause is relative motion.So induced
torque in damper winding acts in opposition to
instantaneous relative motion.

Author:arbelectbit@yahoo.com

Is This Answer Correct ?    139 Yes 11 No



Post New Answer       View All Answers


Please Help Members By Posting Answers For Below Questions

What are the different losses In a de mac1une'! t.xplam

2271


i have applied for junior engineer 2 c&w for Guwahati RRB please send me last five year question paper

1599


how to calculate singlephase motor efficiency?

1733


Dear sir, In our plant have Station Transformer having capacity,i want to know, why LV side 40 - 40MVA is given? & how we can get 6.3 KV supply from tertiary(i.e. Open delta connection), Vector Group YNyn0 - yn0 +d MVA Rating 80MVA / 40 - 40MVA + 26.7MVA Voltage rating 420 (Tap range +6,to -10)81.25% /11.5KV - 11.5KV +6.3KV

1759


what is meant by the phrase 'static load' in case of shorting in a generator excitation system?

1715






can i use 2000/5A Clamp meter to measure HT cable

1568


why do we put a transformer on soak before loading it

663


On Which Pressure PRV is operated.

1281


upto how much low RPM we will run the commercial motor which is run through VFD without any problem occurs in motor.Motor rating Duty is S1 & RPM is 1400.

1640


What are the classifications of oscillators?

684


How many sprinklers should be in one pipe line?

1428


in wind mill use 2100 kw asychronous generator ( induction generator ) rotor voltage : 3300,stator voltage : 690, rpm : 1511 type : MRL063E04 ' we check rotor resistance magger value found following. R-EARTH - 00 M.OHM,Y-EARTH-34 M.OHM,B-EARTH- 33M.OHM R-Y: 31 M.OHM, Y-B: 00 M.OHM,B-R :33 M.OHM HOW CAN I TAKE DECISION?pls ans. quickly

1884


v/f drive basic princeple

2004


anyone knows service engineer in chennai for EDM SPARKING MACHINE.CHMER PULSE CD 60 M.pL GIVE ANY CONTACT NOS

1977


Is there any Electrical supervisor license which gives permit to work whole India rather than individual state??

1397