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Why is stationary armature preffered you commercial generators than moving armature?
Wiki User
∙ 10y ago
The problem with a generator having a rotating armature is that the armature must be connected to its external load via slip rings and brushes. As power station alternators generate voltages up to 25 kV or so, and supply hundreds of amperes, the resulting arcing at the slip rings would be severe, and would require short maintenance cycles. Accordingly, it makes more sense for the armature to be stationary, and connected directly to its load, and have the field winding rotate instead, because the voltage/current applied to the field winding is quite low.
Wiki User
∙ 10y ago
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Explain the working principle of shunt generator?
A shunt generator is a machine with a rotating set of coils of wire embedded in the iron core in its armature (the spinning part), and a 'commutator' and brushes that carry the current from the (spinning) windings on the armature to the stationary external electrical load. It also has a 'field' winding that creates a stationary magnetic field inside the machine, that the armature coils are spun in. As the windings spin, they cut the stationary field and generate an alternating voltage. As well as providing a moving connection to the coils, the commutator and brushes act like a switch, reversing the connections from the coils to the external circuit each time the waveform changes polarity from positive to negative and vice versa. This creates direct current in the external circuit and load. In a shunt generator, the field windings are connected in parallel with the armature ('shunt' is a common term for 'in parallel') and the field gets its power ('excitation') from the armature - the machine is 'self-excited'. A self-excited generator needs a small 'residual field' in the field's iron core so it can generate a small output from the armature when starting, which is fed to the field, boosting the armature output, which is fed to the field.... and so on, until the field iron core saturates with flux, and the field stops strengthening. Shunt generators are the 'workhorse of the small generator market - they are cheap and simple, have an output voltage that 'droops' a little with increasing load, and most shunt generators can safely be short-circuited - this takes the electrical energy away from the field, and the armature can usually develop only a small output current - not enough to damage it.
What is stator of the armature?
The 'stator' is the generic term for the stationary parts of a machine, including its frame, magnetic circuit, poles, windings, etc.
What is armature in motors?
The armature has the stationary (not physically moving) magnetic field, which attracts the magnetic field in the rotor. Since DC does not alternate, a split ring is used to alternate the current (and resulting magnetic field), so that the rotor will spin.
What is the difference between a field winding and an armature winding in any machine?
simply saying u that field winding is a winding present at the stator of the motor and is used to produce the magnetic field and the armature winding is the winding present in the rotor and is used to rotate the shaft of the motor. there are some machines with permanent magnets, those permanent magnets are used as the major source of magnetic flux in the machine instead of the field winding .
What is a compound dc generator?
generators are machines that convert machanical energy to electrical energy and could be AC or DC. if in a DC generator has it field armature connection in both series and parallel its said to be compound dc generator.
Can a car monitor in the back seat be mounted to a movable armature, or do they have to be stationary?
They can only be stationary.
Why is a rotating field system used in preference toa stationary field?
If you are asking why most a.c. generators (alternators) use a rotating field, rather than a rotating armature, then the answer is that a rotating armature would require slip rings to carry huge currents and be insulated for high voltages, which is not practicable.
Is it true that large generators use armature similar to those in a motor?
yes
How do you spell amiture?
The correct spelling is armature (wound coil in motors and generators).
What is the difference between shunt generators and series generators?
1. In Shunt generators armature current is equal to sum of field current and load current whereas in series generators field current and load current is same. 2. Shunt generators field winding has high resistance and large no of turns as compared to series generators. 3. Shunt generator field winding has thin conductor and series generator has thick.
How the generator and motor works ALTERNATING CURRENT GENERATORS BASIC AC GENERATORS Regardless of size all electrical generators whether dc or ac depend upon the principle of magneticinduction.?
An emf is induced in a coil as a result of (1) a coil cutting through a magnetic field, or (2) a magnetic field cutting through a coil. As long as there is relative motion between a conductor and amagnetic field, a voltage will be induced in the conductor. That part of a generator that produces the magnetic field is called the field. That part in which the voltage is induced is called the armature. Forrelative motion to take place between the conductor and the magnetic field, all generators must have two mechanical parts - a rotor and a stator. The ROTor is the part that ROTates; the STATor is the part that remains STATionary. In a dc generator, the armature is always the rotor. In alternators, the armature may be either the rotor or stator. ROTATING-ARMATURE ALTERNATORSThe rotating-armature alternator is similar in construction to the dc generator in that the armature rotates in a stationary magnetic field as shown in figure 3-1, view A. In the dc generator, the emf generated in the armature windings is converted from ac to dc by means of the commutator. In the alternator, the generated ac is brought to the load unchanged by means of slip rings. The rotating armature is found only in alternators of low power rating and generally is not used to supply electric power in large quantities.
How does a small generator produce current?
It doesn't! It produces voltage. It does this by the relative movement between an armature (winding into which a voltage is induced) and a magnetic field (set up by field windings). Either the armature rotates inside a fixed field (small generators) or the field rotates within a fixed armature (larger generators).Current is only supplied when a load is connected to the generator.
How do car generators work?
A car generator is a DC motor. If you apply power to a working DC motor, it will turn the armature and produce work. If you turn the armature of a working DC motor, it will produce power. Generators in cars were replaced during the early 1960's with alternators.
What Is cross coil gauge?
This type of gauge has an armature (magnet) that is mounted on the pointer shaft. The armature is surrounded by the stationary cross coils. These three coils are wound across each other
What are field windings and armature windings in a dc motor and generator?
generators have two types of winding , * at armature also called armature winding( winding around shaft , we can say), which is the moving part. note that armature also consists of magnets along with windings. hence produces field arount it. * and at stator also called field winding, because when armature rotates its flux(field) is cutted by the stator windings and produces mutually induced e.m.f in it( in stator windings off course) causing current to flow. this current also produces some electric field around it which is in return cutted by the armature windings hince a little amount of e.m.f ( also called back e.m.f) produced in armature due to stator winding current. know this current in armature (due to back e.m.f produced by stator winding) produces additional field , hence causing more current in stator winding. this is the reason that why stator windings are called field winding( as they cause electric field of armature stronger and cause more current in output). note that out put is taken from the stator windings in generators.
Explain the working principle of shunt generator?
A shunt generator is a machine with a rotating set of coils of wire embedded in the iron core in its armature (the spinning part), and a 'commutator' and brushes that carry the current from the (spinning) windings on the armature to the stationary external electrical load. It also has a 'field' winding that creates a stationary magnetic field inside the machine, that the armature coils are spun in. As the windings spin, they cut the stationary field and generate an alternating voltage. As well as providing a moving connection to the coils, the commutator and brushes act like a switch, reversing the connections from the coils to the external circuit each time the waveform changes polarity from positive to negative and vice versa. This creates direct current in the external circuit and load. In a shunt generator, the field windings are connected in parallel with the armature ('shunt' is a common term for 'in parallel') and the field gets its power ('excitation') from the armature - the machine is 'self-excited'. A self-excited generator needs a small 'residual field' in the field's iron core so it can generate a small output from the armature when starting, which is fed to the field, boosting the armature output, which is fed to the field.... and so on, until the field iron core saturates with flux, and the field stops strengthening. Shunt generators are the 'workhorse of the small generator market - they are cheap and simple, have an output voltage that 'droops' a little with increasing load, and most shunt generators can safely be short-circuited - this takes the electrical energy away from the field, and the armature can usually develop only a small output current - not enough to damage it.
What is ammature resistance?
Right now a DC engine is begun the armature is stationary and there is no counter EMF being produced. The main part to cutoff beginning current is the armature resistance, which, in most DC engines is a low esteem.
