My questions are: 1. Why does the SLIP induces eddy current on the rotor surface? i.e. Why are the eddy currents produced in the first place? 2. When due to initial loss of excitation, Stator induced voltage (E) is lost and so active power (P) is also lost, so why doesn't the stator winding receive current from the bus (since bus is at rated voltage and stator winding at zero voltage)? And why then doesn't the generator run like induction motor? Thanks
when slip occurs the net flux cut by the rotor surface is comparatively higher which results in eddy current 2. The loading angle may oscillate, machine may go to motoring mode for an instant the active power may swing from positive to negative there are chances for loss of synch also before going to motoring mode the active power falls down instantly but due to PRIMEMOVER it gains supersynch speed and behaves as induction generator
1. When slip occurs the net flux cut by the rotor surface is comparatively higher which results in eddy current 2. The loading angle may oscillate, machine may go to motoring mode for an instant the active power may swing from positive to negative there are chances for loss of synch also.Before going to motoring mode the active power falls down instantly,but due to PRIMEMOVER it gains supersynch speed and behaves as induction generator
1. When slip occurs the net flux cut by the rotor surface is comparatively higher which results in eddy current - OK. 2. The loading angle may oscillate, machine may go to motoring mode for an instant the active power may swing from positive to negative there are chances for loss of synch also. Before going to motoring mode the active power falls down instantly, but due to PRIMEMOVER it gains supersynch speed and behaves as induction generator. During induction generator the emf is re-established by taking excitation from grid My Question: When the generator starts taking VARs from the grid (due to loss of Field) its means its taking current from the grid into the stator windings, right? [pls correct me if i'm wrong here] So it means there is a 3 phase rotating field developed in the stator winding which cuts the rotor winding, right? That means that voltage is induced on the rotor windings? Since rotor windings are closed looped therefore current should flow in the rotor windings. That rotor current has its own field which should interact with the stator flux? What happens next? and is the logic correct? pls correct where i'm wrongs. Thanx
Yes, through stator winding the VAR is absorbed. After interaction of stator and rotor magnetic field the resultant air gap flux rotates at synch speed but rotor rotates at higher speed (N>Ns) which results in eddy currents over rotor surface. In synchronous operation the rotor speed is same as the speed of rotating air gap field, so there is no rate of change of flux wrt to rotor surface.
Thanks for this educational video. Perfectly explained in simplicity. Great job!!
simply superb. keep the gud work on.
Very Good Lecture
Excellent lecture Sir. Thanks
Excellent !
Dear atish hi..
What is generator dead machine protection..
Please describe..
I want to know..
We have reverse power protection which won't allow current from grid to generator..in such cases what will happen??
P = e v / x . sin teta ?? Not cos teta
My questions are:
1. Why does the SLIP induces eddy current on the rotor surface? i.e. Why are the eddy currents produced in the first place?
2. When due to initial loss of excitation, Stator induced voltage (E) is lost and so active power (P) is also lost, so why doesn't the stator winding receive current from the bus (since bus is at rated voltage and stator winding at zero voltage)? And why then doesn't the generator run like induction motor?
Thanks
when slip occurs the net flux cut by the rotor surface is comparatively higher which results in eddy current
2. The loading angle may oscillate, machine may go to motoring mode for an instant
the active power may swing from positive to negative
there are chances for loss of synch also
before going to motoring mode the active power falls down instantly
but due to PRIMEMOVER
it gains supersynch speed and behaves as induction generator
1. When slip occurs the net flux cut by the rotor surface is comparatively higher which results in eddy current
2. The loading angle may oscillate, machine may go to motoring mode for an instant
the active power may swing from positive to negative
there are chances for loss of synch also.Before going to motoring mode the active power falls down instantly,but due to PRIMEMOVER
it gains supersynch speed and behaves as induction generator
During induction generator the emf is re-established by taking excitation from grid
1. When slip occurs the net flux cut by the rotor surface is comparatively higher which results in eddy current - OK.
2. The loading angle may oscillate, machine may go to motoring mode for an instant the active power may swing from positive to negative there are chances for loss of synch also. Before going to motoring mode the active power falls down instantly, but due to PRIMEMOVER it gains supersynch speed and behaves as induction generator. During induction generator the emf is re-established by taking excitation from grid
My Question: When the generator starts taking VARs from the grid (due to loss of Field) its means its taking current from the grid into the stator windings, right? [pls correct me if i'm wrong here]
So it means there is a 3 phase rotating field developed in the stator winding which cuts the rotor winding, right? That means that voltage is induced on the rotor windings? Since rotor windings are closed looped therefore current should flow in the rotor windings. That rotor current has its own field which should interact with the stator flux? What happens next? and is the logic correct? pls correct where i'm wrongs.
Thanx
Yes, through stator winding the VAR is absorbed. After interaction of stator and rotor magnetic field the resultant air gap flux rotates at synch speed but rotor rotates at higher speed (N>Ns) which results in eddy currents over rotor surface.
In synchronous operation the rotor speed is same as the speed of rotating air gap field, so there is no rate of change of flux wrt to rotor surface.
Please do not delete this video
Sir why do you stop making videos? Please share your knowledge, so that people can get some real knowledge of Electrical. Please sir
Godzilla