Question

50 Hz, 6,000 v, 25.000 kW, 2-pole synchronous generator tested.
The results shown in the figure below were obtained.
From the no-load saturation curve, when the terminal voltage Va = 6000 V, the field current if = 546 A.
From the short-circuit curve, when the electron current ia = 2000 A, the field current if = 300 A

Unloaded saturation curve Terminal voltage 6000V 一短卷曲線 2000AL Armature current 0 300A 546A Field current if [A]

Find the rated current

In the short circuit curve, find the field current that will be the rated current

Find the short circuit ratio

Find the synchronous reactance R ohm

Answer 1

Answer is attached...

Solution given 6000 v ľ50ookw Va 6ooov Sa fughton (WUE 19 2000 Зоор Тр, & Field (wun(A) 16 5460 (1) Find Rated current P = √3 VI coso ç cosþ-3 assume Ia crated) 25000 kW Jov 13x6000 1 P To chated) 2405. 62 A () Ifa Field Id curent) at Rated cuvent know that short circuit OS We Curve is lineas, Hanu Ta a Ir la i's proportional to field curent

given, at 2000 A If ( 300A) (Rated) If = 1 2 405.62 ( Rated) If2 = 2405.62 X 300 2000 Ih 360 A It is field curent at Rated curent. Shout chreuit Raho It is defined Raho of field sewent as required to give noted voltage on open clacuit to field current acquired to give auted current on shart ciacuit SIR= If (Voc) If = 546 (at Voc) Tf - 300 (at Isc) SIR IF (Isc) 546 =1.82 300 SCR = 1.82 Ans

(V) Synchymous Reaction х as SIR (Short Claluit Raho) is just the Reciprocal of pea-unit value Saturated Synchaona chaonous geactance SCR = 1 of the XstP4) IXsrul 0.55 P.4 1.82 Now, Zs (box) Synchronous imbedana Zs (base) Voc Is = Isc V 6000 2000 1 Zsa 6000 = 3.464 √3x2000 1466 Xsca þqunit X Zbase - Xs 0.55 X 3.46 Xs (2) z 1.gor Ane synchronous deactanca in ohm