A generator transformer has a magnetising current of 1.5 %. The primary winding voltage is 27 kV and the secondary voltage is 330kV. The transformer rating is 360 MVA. What is the allowable operating current differential, in terms of Amperes on the primary, that should not cause the protection to operate?
Select one:
a. 200.00 Amperes
b. 31.08 Amperes
c. 115.47 Amperes
d. 66.00 Amperes
A generator transformer has a magnetising current of 1.5 %. The primary winding voltage is 27 kV and the secondary voltage is 330kV. The transformer rating is 360 MVA. What is the allowable operating...
Question I The rating of a three phase three winding transformer are: Y-connected 10 KV 40 MVA Secondary Y-connected 22 KV 40 MVA A-connected 4 KV 15 MVA Primary Tertiary Neglecting winding resistance and exciting current, the per unit leakage reactance are: Mps 9.6 % pu on 40 MVA, 11022 KV xm = 7.2 % pu on 40 MVA, I 10/ 4 KV Xsti: 12 % pu on 40 MVA, 22/ 4 KV Determine the era nyimpedances of the transformer...
three-phase transformer is rated at 12 kV/135 kV, 100 MVA. It has the following equivalent circuit parameters (referred to the primary winding where appropriate) : • primary resistance R1 = 0.03 ohms, secondary resistance R2’ = 0.04 ohms • primary leakage reactance X1 = 0.1 ohms, secondary leakage reactance X2’ = 0.1 ohms • magnetising reactance XM = 16 ohms, core-loss resistance RC = 200 ohms. In your calculations, you should use the simplified equivalent circuit. i) The transformer is...
The ratings of a three-phase, three-winding transformer are Y connected, 66 kV, 20 MVA Primary (1): Secondary (2):Y connected, 13.2 kV, 15 MVA Tertiary (3): A connected, 2.3 kV, 5 MVA Neglecting winding resistances and exciting current, the per-unit leakage reactances are: X12 0.08 on a 20-MVA, 66-kV base X13 0.10 on a 20-MVA, 66-kV base X23 0.09 on a 15-MVA, 13.2-kV base (a) Determine the per-unit reactances Xi, X2, X3 of the equivalent circuit on a 20- MVA, 66-kV...
Problem 1: A three-phase transformer has the following name plate data: Rated Power Primary voltage Secondary Voltage Excitation reactance Series Impedance 150 MVA 230 kV 32 kV 30 (pu) 0.02+0.15j (pu) The transformer is Y/A connected. Answer the following questions: a) What are the nominal (rated) primary and secondary line currents?| b) What is the nominal value of the Delta-side winding (internal) current? c) What is the secondary to primary winding turn ratio? d) The transformer is supplying 150 MVA...
A 400-MVA, 200-kV/20-kV, three phase Y-Y transformer has an equivalent series impedance of ZTL = 0.012 + 20.0162 per phase referred to the low-voltage side (secondary side). The transformer is supplying a three-phase load of 300-MVA, 0.8 power factor lagging at terminal voltage of 20 kV (line-to-line) on its low-voltage side (secondary side) as shown in Fig. 22. The primary is supplied from a transmission line with an impedance of ZL = 0.5 + j1.0 per phase. The line-to-neutral load...
A three-phase Yy0 connected transformer has a nominal rating of 250 kVA and a voltage ratio 15:0.4 kV. After conducting the short-circuit test, where the secondary winding is short-circuited, it is found that the primary series resistance is 0.08 pu and the primary series impedance magnitude is 0.1pu. The effect of the parallel branch in the transformer’s equivalent circuit may be neglected. Explain what information ‘Yy0’ gives about the transformer. Draw the per-phase equivalent circuit of the transformer during the...
32. A transformer is to be designed to increase the 30 kV-rms output of a generator to the transmission-line voltage of 345 kV-om. If the primary winding has 80 turns, how many turns must the secondary have? b. 70 c. 920 d. 9200 e 12 33. The primary winding of an electric train transformer has 400 turns and the Secondary has 50. If the input voltage is 120V(rms) what is the output voltage? a. 15 V (rms) b. 30 Vrms)...