Questions:- 1. What happen when the two transformers are operated in parallel having un equal turn's ratio. 2. Why polarity checking is necessary for the parallel operation of single phase transformer. 3. Why the percentage impedance drop of the transformers are kept equal during the parallel operation of the same. 4. Plot cos, and cosP2 against load current for both cases.

Questions:- 1. What happen when the two transformers are operated in parallel having un equal turn's ratio. 2. Why polarity checking is necessary for the parallel operation of single phase transformer. 3. Why the percentage impedance drop of the transformers are kept equal during the parallel operation of the same. 4. Plot cos, and cosP2 against load current for both cases.

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 3.34P: Three single-phase, two-winding transformers, each rated 450MVA,20kV/288.7kV, with leakage reactance...

See similar textbooks

Similar questions

Three single-phase two-winding transformers, each rated 3kVA,220/110volts,60Hz, with a 0.10 per-unit leakage reactance, are connected as a three-phase extended autotransformer bank, as shown in Figure 3.36(c). The low-voltage winding has a 110 volt rating. (a) Draw the positive-sequence phasor diagram and show that the high-voltage winding has a 479.5 volt rating. (b) A three-phase load connected to the low-voltage terminals absorbs 6 kW at 110 volts and at 0.8 power factor lagging. Draw the per-unit impedance diagram and calculate the voltage and current at the high-voltage terminals. Assume positive-sequence operation.
Three single-phase, two-winding transformers, each rated 450MVA,20kV/288.7kV, with leakage reactance Xeq=0.10perunit, are connected to form a three-phase bank. The high-voltage windings are connected in Y with a solidly grounded neutral. Draw the per-unit equivalent circuit if the low-voltage windings are connected (a) in with American standard phase shift or (b) in Y with an open neutral. Use the transformer ratings as base quantities. Winding resistances and exciting current are neglected.
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) -
What is the maximum volt-ampere rating of transformers supplying Class 2 systems? ___________
1.a. For performing dielectric-strength tests on insulating materials, two transformers are connected in aA. parallel combination.B. cascade arrangement.C. polyphase arrangement. 1.b. In large power transformers, the unequal voltage distribution caused by voltage surges in the winding isprevented by the use ofA. static shields.B. series capacitors.c. low-voltage arresters.
Consider the three single-phase two-winding transformers shown in Figure. 3. The high-voltage windings are connected in Y. (a) For the low-voltage side, connect the windings in A, and label the terminals a, b, and c in accordance with the American standard. (b) Relabel the terminals a', b', and c' such that VAN is 90° out of phase with V₂'b' for positive sequence. DI H₂ Figure. 3: Three-Winding Transformer
What are the conditions for the parallel operation of 1-phase transformers?
Two 11,000/2,200-V, 1-phase transformers are connected in parallel to supply a total load of 200 at 0.8 p.f. lagging at 2,200 V. One transformer has an equivalent resistance of 0.4 ohms and equivalent reactance of 0.8 ohms referred to the low-voltage side. The other has equivalent resistance of 0.1 ohms and a reactance of 0.3 ohms. Determine the current and power supplied by each transformer.
List and describe three (3) losses that occur in power transformers.
What is the influence of transformer connections in single-phase transformers connected for 3- phase operation
Name two types of Transformers equivalent circuit and then compare them.
1- What are the advantages and disadvantages of Back To Back Test on Two Similar Single Phase transformers test ?