answersLogoWhite

0

synchronous impedance can be calculated by performing oc test and sc test.

by oc test,since the armature current is zero Vt=Ef .

in short circuit test ,entire emf is consumed in circulating the short circuit current Isc,through the synchronous impedance.

Zs=Ef/Isc.= (open ckt. terminal voltage for a certain field current)/(short ckt. current at the same field current)

User Avatar

Wiki User

12y ago

What else can I help you with?

Continue Learning about Electrical Engineering

Why is speed not normally used to control the armature voltage of a synchronous alternator?

Because if speed was used, the power system frequency would be changed. A synchronous generator spins at synchronous speeds. Synchronous generators 101: A typical synchronous generator will have a field winding (typically on the rotor, or rotating part) and a stator winding (the stationary part where power is supplied to the power grid). Current is injected into the field winding, turning it into an electromagnet. This field current is controlled by the Automatic Voltage Regulator (AVR). The more current supplied to the field winding, the stronger the electromagnet becomes, and the more power is required from the prime mover (whatever is supplying the power - steam turbine, for example) to keep the generator spinning at synchronous speeds.


What is the excitation system in a generator used for?

The excitation system is used to control the excitation of the rotating field in the armature. By increasing the armature current, it in turn increases the magnetic flux in the armature coil. This has the effect of increasing the voltage output of the generator. By lowering the armature current this in turn lowers the generator output voltage. The generator's voltage regulator automatically adjusts the output voltage continuously as the applied load on the generator changes.


What is meant by shaft and commutator in the armature?

The armature is the moving part of a motor or generator. Tthe shaft is the central rod on which the armature rotates. The commutator is the part that transfers the power too or from the moving windings in the armature to the static part of the motor or generator (either too or from the electricity supply).


Does armature rotates?

Typically the armature windings are in the stator of a generator, which does not rotate. Typically the field windings are on the rotor, which rotates.


What are the effect of armature reaction in DC machine and how the armature reaction is minimise?

Armature reaction is the interaction between the magnetic flux produced by armature current and that of the main magnetic field in an electric motor or generator.

Related Questions

Why dc shunt generator does not have armature resistance?

It does have armature resistance.


How the synchronous impedence and armature resistance can be determined in a synchronous generator?

synchronous impedance can be calculated by performing oc test and sc test. by oc test,since the armature current is zero Vt=Ef . in short circuit test ,entire emf is consumed in circulating the short circuit current Isc,through the synchronous impedance. Zs=Ef/Isc.= (open ckt. terminal voltage for a certain field current)/(short ckt. current at the same field current)


What determinesthe amount of current produced in the armature of a generator?

The amount of current produced in the armature of a generator is primarily determined by the voltage induced in the armature winding, the resistance of the circuit, and the load connected to the generator. According to Ohm's Law, current (I) is equal to voltage (V) divided by resistance (R) (I = V/R). Additionally, factors such as the speed of rotation of the generator, the strength of the magnetic field, and the number of turns in the coil also influence the induced voltage and, consequently, the current generated.


A 100KVA DC GENERATOR HAS ARMATURE RESISTANCE 0.02 OHMS AND A SERIES FIELD RESISTANCE 0.004 OHMS WHAT IS THE ARMATURE GENETATED VOLTAGE?

There is not enough information to answer the question. A DC generator is never described in kVA because DC generators are specified in terms of kilowatts.


What is synchronous reactance in alternator?

The overall reactance of the armature winding is the sum of its leakage reactance plus fictitious reactance, which is known as synchronous reactance (Xs).Xs=XL+Xarwhere XL and Xar are in Ω/phase. Therefore, Xs is in Ω/phase.The impedance of armature winding is obtained by combining its resistance and its synchronous reactance.


What is synchronous reactance?

Synchronous Reactance (in a generator analysis domain) is and equivalent series per-phase inductance term (think per-phase winding resistance) and is mainly composed of the machine's per-phase leakage inductance (equivalent series inductance of primary and secondary flux leakage) and armature reaction (distortion in flux introduced by an armature current in a machine, once again on a per-phase basis; described as a series inductance). L_SyncReac=L_leakage+L_ArmatureReaction. That sort of touches the surface of synchronous reactance.


What is armature reactions in a synchronous machine?

Armature reaction is the effect of armature flux on the flux generated by the fied windings.Cross magnetisation and Demagnetising are its consequences.


Why are synchronous generators called synchronous?

somthing that sycronizes stuff in a genorator


What kind of current flows in the armature conductor of a dc generator?

pogi current flow in the armature conductor


In DC motor is the armature plus brushes resistance substantially the same for every rotational position of the armature why?

In a DC motor, the armature resistance and brush contact resistance remain relatively constant across different rotational positions because these components are primarily resistive and do not change with position. The brushes continuously maintain contact with the commutator segments as the armature rotates, ensuring a consistent electrical path. While the inductance and back EMF may vary with position, the resistance itself is a fixed characteristic determined by the materials and design of the armature and brushes. Therefore, the overall resistance remains substantially the same throughout the armature's rotation.


Why is speed not normally used to control the armature voltage of a synchronous alternator?

Because if speed was used, the power system frequency would be changed. A synchronous generator spins at synchronous speeds. Synchronous generators 101: A typical synchronous generator will have a field winding (typically on the rotor, or rotating part) and a stator winding (the stationary part where power is supplied to the power grid). Current is injected into the field winding, turning it into an electromagnet. This field current is controlled by the Automatic Voltage Regulator (AVR). The more current supplied to the field winding, the stronger the electromagnet becomes, and the more power is required from the prime mover (whatever is supplying the power - steam turbine, for example) to keep the generator spinning at synchronous speeds.


Why armature resistance is less than 1 Ohm?

why armature resistance is very low as compare to field resistance in dc motor