Because the saturation is not taken into consideration so the impedance calculated is more than the impedance that would have resulted once the saturation is taken into account.-- By Ankit(bigboss0086@gmail.com)
Synchronous impedance is also known as the EMF method. It is a ratio of open circuits to short circuits, when they both are referred to the same field excitation.
The lower the impedance, the lower the voltage drop across the transformer as it is loaded. This means regulation is better, since voltage variance is smaller.
raised voltage output
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)
To get all the audio voltage from a source to a target without loss you need voltage bridging, that is a relative low output impedance to a higher input impedance. Usualy the input impedance is at least ten times higher then the output impedance.An input impedance is called also a load impedance or an external impedance.An output impedance is called also a source impedance or an internal impedance.
It is conducting OC and SC tests on the given three phase alternator and determining the regulation by synchronous impedance method.
Synchronous impedance is also known as the EMF method. It is a ratio of open circuits to short circuits, when they both are referred to the same field excitation.
The lower the impedance, the lower the voltage drop across the transformer as it is loaded. This means regulation is better, since voltage variance is smaller.
in modern trend, synchronous impedance of alternator should be high. If impedance are more than voltage drop across its arm. Wdg. Is more .according to the phasor diagram of alternator if IaXs componant is more than magnitude of induced emf will also be increased.
The lower the impedance, the lower the voltage drop across the transformer as it is loaded. This means regulation is better, since voltage variance is smaller.
raised voltage output
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)
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)
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.
Simple addition, but it must be done with complex numbers.
That depends on the output impedance. In electronic we use voltage bridging, that is a relative low output impedance to a higher input impedance. Usualy the input impedance is more than ten times higher then the output impedance. An input impedance is called also a load impedance or an external impedance. An output impedance is called also a source impedance or an internal impedance.
I assume by good regulation you mean a minimal voltage drop internal to the generator. Minimizing this will inherently increase the short circuit current, because it requires minimizing the internal impedance of the generator.