What is leakage reactance in synchronous machine?
HE ARMATURE leakage may be defined as the reactance due to the difference between the total flux produced by an armature current and the flux in the airgap produced by the same armature current.
What is synchronous reactance of generator?
The Synchronous Reactance (XS) is the imaginary reactance employed to account for the voltage effects in the armature circuit produced by the actual armature leakage reactance and by the change in the air gap flux caused by the armature reaction.
Is synchronous reactance constant?
In electrical machinery and power systems, the synchronous reactance is treated as a constant reactance in series with the generated emf and is independent of load condition.
What is unsaturated synchronous reactance?
The unsaturated synchronous reactance (denoted by Xsu) can be obtained from the air-gap line voltage and the short-circuit current of the alternator for a particular value of the field current. Note – SCC is the short-circuit characteristic.
What is leakage reactance?
Leakage reactance is usually the most important element of a power system transformer due to power factor, voltage drop, reactive power consumption and fault current considerations. Leakage inductance depends on the geometry of the core and the windings.
How is synchronous reactance of synchronous generator determined?
- R a = Armature resistance.
- X s = Synchronous reactance ( X L + X a )
What is synchronous reactance and synchronous impedance?
Both the armature reaction reactance and the leakage reactance are present at the same time. The two raeactances are combined together and the sum is called the Synchronous reactance (Xs). Xs = Xal + Xar. The combined result of the Synchronous reactance and armature resistance is called Synchronous Impedance (Zs).
How do you calculate synchronous reactance?
What is constant in synchronous generator?
Synchronous generators can operate in P-V (constant active power and terminal voltage) or P-Q (constant active and reactive power) modes while in a grid-connected operation.
How do you calculate leakage reactance?
X1 and X2 = leakage reactance of primary and secondary winding resp. Z1 and Z2 = Primary impedance and secondary impedance resp. Z1 = R1 + jX1 …and Z2 = R2 + jX 2 . E1 and E2 = induced emf in primary and secondary winding respectively.
Why SCC of an alternator is linear?
As the resultant air gap flux is only 0.15 of its rated value under normal voltage condition, such a low value of air gap flux does not saturate the iron parts of synchronous machine and hence the short circuit characteristics is a straight line.