Contents
Is field current and load current same?
What is Field Current When Load Current Is Given? Field current when load current is given current flows in field winding or stationary winding of Motor or generator is called field current is calculated using field_current = Armature Current-Load current.
What happen to the load current when the load resistance of a shunt generator is increase?
External Characteristic of Shunt Wound DC Generator Ohmic drop due to armature resistance gives lesser terminal voltage the generated voltage. When the load resistance of a shunt wound DC generator is decreased, then load current of the generator increased as shown in above figure.
What happens if the load current increases in case of DC motor *?
In case of DC shunt motor, the flux per pole is considered to be constant, torque increases with the increase of load current. If the load current increases then the armature current also be increased and the speed slightly falls due to increase in voltage drop in armature.
What happens in a shunt motor if the field winding circuit is opened under load?
As mentioned above if the field circuit is opened, the back emf will drop to zero. The motor will try to speed up to develop a back-emf and with no field it requires a very large armature current. That is why one never starts a shunt motor without the field winding excited.
What happens if series motor is operated on no load?
A series motor should never be started at no load. With no mechanical load on the series motor, the current is low, the counter-EMF produced by the field winding is weak, and so the armature must turn faster to produce sufficient counter-EMF to balance the supply voltage. The motor can be damaged by overspeed.
What happens when we increase the field current in a motor?
First, we suppose that the motor is connected with inductive load (lagging P.F) so if we increase the field current (I F) it effect is drawn in a given figure. We observe that with the increment of field current internal generated voltage increases but there is no effect on power provided by motor.
Why does the current increases when the load increases?
Now during sudden increase in load, the conductors fall back more and begin to cut the rotating field thus causing more increase in induced emf.
How does VSI affect the secondary load current?
A voltage, Vsi, is also induced in the secondary winding causing secondary current to flow. The ampere-turns created by the secondary current work against the induced voltage that opposes the source voltage. Consequently, the source voltage supplies more current flow through the primary.
How does an armature winding work in a generator?
When operating as a generator, the armature winding is rotated through the field, generating a DC voltage that is delivered to the load. For motor operation, the armature winding draws current from the source, and the current in the armature coils interacts with the field to create an electromagnetic torque that drives a mechanical load.