Three coils each having resistance of 3 Q and capacitive reactance of 4 Q are connected in delta to A7 415V, 50HZ, 3 phase supply. The power factor is (а) 0.60 (b) 0.80 (c) 0.75 (d) 0.99 A 1000 V/440 V, single-phase transformer takes a no-load current of 0.6 A and the iron loss is 300 W. A8 The core loss component of the no-load current (Iw) is , A (а) 0.2 (b) 0.68 (c) 1.14 (d) 0.3

Three coils each having resistance of 3 Q and capacitive reactance of 4 Q are connected in delta to A7 415V, 50HZ, 3 phase supply. The power factor is (а) 0.60 (b) 0.80 (c) 0.75 (d) 0.99 A 1000 V/440 V, single-phase transformer takes a no-load current of 0.6 A and the iron loss is 300 W. A8 The core loss component of the no-load current (Iw) is , A (а) 0.2 (b) 0.68 (c) 1.14 (d) 0.3

Power System Analysis and Design (MindTap Course List)

6th Edition

ISBN:9781305632134

Author:J. Duncan Glover, Thomas Overbye, Mulukutla S. Sarma

Publisher:J. Duncan Glover, Thomas Overbye, Mulukutla S. Sarma

Chapter3: Power Transformers

Section: Chapter Questions

Problem 3.16P: A single-phase, 50-kVA,2400/240-V,60-Hz distribution transformer has the following parameters:...

See similar textbooks

Similar questions

For an ideal 2-winding transformer, an impedance Z2 connected across winding 2 (secondary) is referred to winding 1 (primary) by multiplying Z2 by (a) The turns ratio (N1/N2) (b) The square of the turns ratio (N1/N2)2 (c) The cubed turns ratio (N1/N2)3
The ratings of a three-phase three-winding transformer are Primary(1): Y connected 66kV,15MVA Secondary (2): Y connected, 13.2kV,10MVA Tertiary (3): A connected, 2.3kV,5MVA Neglecting winding resistances and exciting current, the per-unit leakage reactances are X12=0.08 on a 15-MVA,66-kV base X13=0.10 on a 15-MVA,66-kV base X23=0.09 on a 10-MVA,13.2-kV base (a) Determine the per-unit reactances X1,X2,X3 of the equivalent circuit on a 15-MVA,66-kV base at the primary terminals. (b) Purely resistive loads of 7.5 MW at 13.2 kV and 5 MW at 2.3kV are connected to the secondary and tertiary sides of the transformer, respectively. Draw the per- unit impedance diagram, showing the per-unit impedances on a 15-MVA,66-kV base at the primary terminals.
A single-phase, 50-kVA,2400/240-V,60-Hz distribution transformer has the following parameters: Resistance of the 2400-V winding: R1=0.75 Resistance of the 240-V winding: R2=0.0075 Leakage reactance of the 2400-V winding: X1=1.0 Leakage reactance of the 240-V winding: X2=0.01 Exciting admittance on the 240-V side =0.003j0.02S (a) Draw the equivalent circuit referred to the high-voltage side of the transformer. (b) Draw the equivalent circuit referred to the low-voltage side of the transformer. Show the numerical values of impedances on the equivalent circuits.
(a) An ideal single-phase two-winding transformer with turns ratio at=N1/N2 is connected with a series impedance Z2 across winding 2. If one wants to replace Z2, with a series impedance Z1 across winding 1 and keep the terminal behavior of the two circuits to be identical, find Z1 in terms of Z2. (b) Would the above result be true if instead of a series impedance there is a shunt impedance? (c) Can one refer a ladder network on the secondary (2) side to the primary (1) side simply by multiplying every impedance byat2 ?
For an ideal transformer, the efficiency is (a) 0 (b) 100 (c) 50
A 23/230-kV step-up transformer feeds a three-phase transmission line, which in turn supplies a 150-MVA,0.8 lagging power factor load through a step-down 230/23-kV transformer. The impedance of the line and transformers at 230kVis18+j60. Determine the tap setting for each transformer to maintain the voltage at the load at 23 kV.
In order to avoid difficulties with third-harmonic exciting current, which three-phase transformer connection is seldom used for step-up transformers between a generator and a transmission line in power systems. (a) Y- (b) -Y (c) Y-Y
For a short-circuit test on a 2-winding transformer, with one winding shorted, can you apply the rated voltage on the other winding? (a) Yes (b) No
In no load phasor diagram of practical transformer, the magnetizing current Imag is with flux Ø O Leading by 30° O Lagging by 60° In phase O 90° out of phase
Seconday winding of transformer is made-up of material. O insulated CRGO conductor O insulated copper conductor O Cold Rolled Grain Oriented (CRGO) conductor Cold Rolled Grain Oriented (CRGO) Silicon Steel
In no load phasor diagram of practical transformer, the magnetizing current Imag is with primary voltage Vp. O Leading by 30° O 90° out of phase O In phase O Lagging by 60°
A 4 kVA, 400 V/200 V single phase transformer has resistance of 0.02 p.u. and reactance of 0.06 p.u. The resistance and reactance referred to HV side are