Given a 20 kVA, 50 Hz, 2000/200 V single-phase transformer. The parameters of thetransformer equivalent circuit are: R1 = 0.5 2, R2 = 0.005 0, X1 = 0.5 2, X2 = 0.005 N. Theexcitation impedance parameters referred to LVS are: Rc 500 n and XM = 50 n. Thetransformer is fully-loaded at 0.8 PF lagging and the load voltage is maintained at 200 V.Using the approximate L-equivalent circuit, the voltage regulation of the transformer is:3.45 %5.2 %0.7 %7.1 %

In this question we need to find a voltage regulation of transformer

Given a 20 kVA, 50 Hz, 2000/200 V single-phase transformer. The parameters of the transformer equivalent circuit are: R1 = 0.5 2, R2 = 0.005 n, X1 = 0.5 2, X2 = 0.005 N. The excitation impedance parameters referred to LVS are: Rc 500 n and XM = 50 2. The transformer is fully-loaded at 0.8 PF lagging and the load voltage is maintained at 200 V. Using the approximate L-equivalent circuit, the voltage regulation of the transformer is: 3.45 % 5.2 % 0.7 % 7.1 %

Given a 20 kVA, 50 Hz, 2000/200 V single-phase transformer. The parameters of the transformer equivalent circuit are: R1 = 0.5 2, R2 = 0.005 n, X1 = 0.5 2, X2 = 0.005 N. The excitation impedance parameters referred to LVS are: Rc 500 n and XM = 50 2. The transformer is fully-loaded at 0.8 PF lagging and the load voltage is maintained at 200 V. Using the approximate L-equivalent circuit, the voltage regulation of the transformer is: 3.45 % 5.2 % 0.7 % 7.1 %

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 3.14P: A single-phase 50-kVA,2400/240-volt,60-Hz distribution transformer is used as a step-down...

See similar textbooks

Similar questions

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.
An infinite bus, which is a constant voltage source, is connected to the primary of the three-winding transformer of Problem 3.53. A 7.5-MVA,13.2-kV synchronous motor with a sub transient reactance of 0.2 per unit is connected to the transformer secondary. A5-MW,2.3-kV three-phase resistive load is connected to the tertiary Choosing a base of 66 kV and 15 MVA in the primary, draw the impedance diagram of the system showing per-unit impedances. Neglect transformer exciting current, phase shifts, and all resistances except the resistive load.
(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 ?
An ideal transformer has no real or reactive power loss. (a) True (b) False
The direct electrical connection of the windings allows transient over voltages to pass through the auto transfonner more easily, and that is an important disadvantage of the autotransformer. (a) True (b) False
Consider Figure 3.4. For an ideal phase-shifting transformer, the imda nce is unchanged when it is referred from one side to the other. (a) True (b) False
Rework Problem 3.14 if the transformer is delivering rated load at rated secondary voltage and at (a) unity power factor, (b) 0.8 power factor leading. Compare the results with those of Problem 3.14. -
How many transformers are needed to make an open-delta connection?
In per-unit equivalent circuits of practical three-phase transformers, under balanced thr-phase operation, in which of the following connect ions would a phase-shifting transformer come up? (a) Y-Y (b) Y- (c) -
Reconsider Problem 3.64 with the change that now Tb includes both a transformer of the same turns ratio as Ta and a regulating transformer with a 4 phase shift. On the base of Ta, the impedance of the two comp onents of Tb is jO.1 per unit. Determine the complex power in per unit transmitted to the load through each transformer. Comment on how the transformers share the real and reactive pors.
Consider Figure 3.25 of the text for a transformer with off-nominal turns ratio. (i) The per-unit equivalent circuit shown in part (c) contains an ideal transformer which cannot be accommodated by some computer programs. (a) True (b) False (ii) In the - circuit representation for real c in part (d), the admittance parameters Y11 and Y12 would be unequal. (a) True (b) False (iii) For complex c, can the admittance parameters be synthesized with a passive RLC circuit? (a) Yes (b) No
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