0
How armature resistance can be determined in a synchronous generator?
Wiki User
∙ 11y ago
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)
Wiki User
∙ 11y ago
Wiki User
∙ 11y agodc generators and motors have armatures
synchronous motors or generators have a permanent or dc magnet in the rotor
Add your answer:
Earn +20 pts
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.
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)
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
Why armature resistance is less than 1 Ohm?
why armature resistance is very low as compare to field resistance in dc motor
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 are the responses of fall of terminal voltage of a separately excited dc generator?
reactance,armature ohmic resistance(Ri) and armature reaction V=E-IaRa-Ia if Ia is small the voltage will be small too It=Ie-IL
If A generator has an armature resistance of 0.6 ohms and when connected to a load of 40.9 ohms passes a current of 3.5 A what is the terminal voltage and generated EMF?
145.25 v
