Generator T 480 V Line Load Z, = 1.5 + j 102 14,400/480 V 480/14,400 V 1000 kVA R= 0.010 pu X = 0,040 pu 500 kVA Lond = R= 0.020 pu X = 0.085 pu 0.45L36.87° Y-connected In the transmission system shown in the figure above, the rated kVA of transformer 1, T1, is 1000 kVA and the rated kVA of transformer 2, T2, is 500 kVA. Transformers pu impedances are given on their rated powers. What is the real power in kWatts supplied to the load?

Generator T 480 V Line Load Z, = 1.5 + j 102 14,400/480 V 480/14,400 V 1000 kVA R= 0.010 pu X = 0,040 pu 500 kVA Lond = R= 0.020 pu X = 0.085 pu 0.45L36.87° Y-connected In the transmission system shown in the figure above, the rated kVA of transformer 1, T1, is 1000 kVA and the rated kVA of transformer 2, T2, is 500 kVA. Transformers pu impedances are given on their rated powers. What is the real power in kWatts supplied to the load?

Delmar's Standard Textbook Of Electricity

7th Edition

ISBN:9781337900348

Author:Stephen L. Herman

Publisher:Stephen L. Herman

Chapter28: Three-phase Transformers

Section: Chapter Questions

Problem 4RQ: An open-delta three-phase transformer system has one transformer center-tapped to provide a neutral...

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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.
Rework Example 3.12 for a+10 tap, providing a 10 increase for 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.
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For an ideal transformer, the efficiency is (a) 0 (b) 100 (c) 50
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