4. Two 100KW, 1phase transformer are connected in parallel both on the primary and secondary. One transformer has an ohmic drop of 0.5% at FL and inductive drop of 8% at FL current. The other has an ohmic drop of 0.75% and inductive drop of 2%. Show how they share a load of 130 kW at 0.9 pf lagging.

4. Two 100KW, 1phase transformer are connected in parallel both on the primary and secondary. One transformer has an ohmic drop of 0.5% at FL and inductive drop of 8% at FL current. The other has an ohmic drop of 0.75% and inductive drop of 2%. Show how they share a load of 130 kW at 0.9 pf lagging.

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 3.5MCQ: For an ideal 2-winding transformer, an impedance Z2 connected across winding 2 (secondary) is...

See similar textbooks

Similar questions

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
For an ideal transformer, the efficiency is (a) 0 (b) 100 (c) 50
An ideal transformer has no real or reactive power loss. (a) True (b) False
A single-phase step-down transformer is rated 13MVA,66kV/11.5kV. With the 11.5 kV winding short-circuited, rated current flows when the voltage applied to the primary is 5.5 kV. The power input is read as 100 kW. Determine Req1andXeq1 in ohms referred to the high-voltage winding.
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 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.
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.
Consider an ideal transformer with N1=3000andN2=1000 turns. Let winding 1 be connected to a source whose voltage is e1(t)=100(1| t |)volts for 1t1ande1(t)=0 for | t |1 second. A2- farad capacitor is connected across winding 2. Sketch e1(t),e2(t),i1(t),andi2(t) versus time t.
(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 ?
A single-phase transformer has a voltage ratio on open circuit of 7900/660 V. The primary and secondary resistances are 0.55 ohm and 0.035 ohm respectively. The corresponding leakage reactances being 4.22 ohm and 0.18 ohm. The load is equivalent to a coil of resistance 3.85 ohm and inductive reactance of 4.2 ohm. Determine the terminal voltage of the transformer and the output in kW when supplying a given load using approximate equivalent circuit when the applied voltage is 7912 V. Your answer
10
The full-load efficiency of transformer at 0.85 lagging p.f. is 97%. Its efficiency at full load 0.85 leading power factor will be *