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Most electrical machines are induction machines, e.g. the motor of vacuum cleaners and refrigerators. The spinning metallic rotor is not connected to the outside mains electrical cables. It has a structure (called a squirrel-cage, since it resembles a cylindrical cage for a small animal) within which electrical currents are induced from the coils of the outside stator, which are connected to the mains supply. As a motor, the squirrel-cage rotor electrical currents oscillate at a slightly slower rate those in the stator, consequently the rotor is 'dragged around', so giving the motor action. However, if the rotating shaft of the same device is forced round faster than the changes in the stator, the machine becomes a generator of electricity. The relative change in speed between the electrical currents in the stator and rotor is called the SLIP; positive for generating action and negative for motor action.
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How can you generate a DC?
U sohuld replace the slip-ring which it is in the AC generator to a commutator. It is a split-ring. Then u can produce DC generator.
Why are slip rings used in an AC generator but not in a DC generator?
Slip rings provide a means for connecting the rotating armature of a simple a.c. generator to an external circuit. As the armature naturally produces an alternating voltage, an alternating voltages is what appears across the slip rings.To obtain a d.c. voltage, it's necessary to reverse the direction of the natural alternating voltage every half cycle, producing full wave rectification. This is achieved using a split-ring commutator which, essentially, is a rotating switch.So, slip rings are used with simple a.c. generators, whereas a commutator is used with d.c. generators.Having said that, however, large modern a.c. generators (alternators) have fixed armatures, and rotating fields, and slip rings are used to supply d.c. field current to the alternator's rotating field windings.
Purpose of slip rings?
slip ring is connect on shaft of motor to collect current from commutator without any complicate connection and with use of it resistors can be insert in circuit and therefore speed control of motor can easily achive
What is excitation in generator and 2 methods each?
when the current is passing through the winding then it is called "Excitation". Types of excitation (1)seperately excited generator. (2)self excited generator. self generator is classified into 3 types. 1.shunt generator. 2.series generator. 3.compound generator. compoud generator is again classified into 2 types. 1.short shunt generator. 2.long shunt generator.
What is the advantages of doubly fed induction generator?
1- can operate in generator/ motor mode for both sub/ super-synchronies speed mode with four possible operation conditions 2-A speed variation of ±30% around synchronous speed can be obtained by the use of power converter of 30% of nominal generated power 3-it has not necessarily to be magnetised from the power grid since it can be magnetised from the rotor circuit too 4- the size of the converter is not related to the total generator power but to the selected speed range and hence to the slip power
What is pole slip in generator?
the link: http://www.av8n.com/physics/power-grid.htm defines pole slip as: " if the load mismatch becomes extreme, one generator could slip 2pi of phase relative to the other. In the industry this is called pole slip".
What is the function of slip rings in ac generator?
They rotate the armature coil.
How can you generate a DC?
U sohuld replace the slip-ring which it is in the AC generator to a commutator. It is a split-ring. Then u can produce DC generator.
What is DC generator?
because DC generator generates generally generate DC power but as it has slip rings which convert it into ac output power
What are the functions of slip ring carbon brush external resistor in an alternalting EMF generator?
good question the use of slipring carbon brush is to give excitement to the generator , as the carbon brosh contact the rotor slip the rotaion and the speed of the generator increases we can say as an external force by anonrafee blueroz_27@yahoo.com
Does a generator produce direct current or alternating current?
A generator produces an alternating current, still it gives d.c. output because we use slip-rings at the terminals of actual output of generator.
Difference between induction motor and induction generator?
in case of induction motor the rotor speed is less than synchronous speed giving positive slip but in case of generator the rptor speed is greater than synchronous speed giving negative slip.......
Is slip ring a part attached to each end of the wire loop in an ac generator?
In a very simple, laboratory-type, a.c. generator -yes. In practical generators, the output (armature) windings are part of the stator, so do not rotate and, so, don't require slip rings.
When slip ring get negative charge in ac generator?
you apply dc voltage to slip rings in synchronous generators polarity will make no difference ( other than when it is first applied )
In the generation of electricity commutator would be used on an alternating current generator and slip rings would be used on a direct current generator?
No. Just the opposite. An AC alternator uses slip rings, a DC generator uses a commutator. Most modern auto alternators are in fact AC alternators that rectify the AC output to DC using a diode bridge.
Generator how it excite its self?
A generator excites it self due to a high power thyristors feeding to a rotor through slip rings. Once excited it lessons maintenance and operational requirements.
What happens if commutator of DC generator is removed?
If the commutator is removed from your generator, you (if you connect slip rings) get AC supply instead of DC supply. the function of the commutator is to convert AC to DC supply and vice versa.Additional AnswerRemoving the commutator will also prevent you from connecting the output of the generator to its load. Remember, the generator's armature is spinning!
