Concept explainers
Three 20-kVA, 24,000/277-V distribution transformers are connected in
The open-circuit test was performed on the low-voltage side of this transformer bank, and the following data were recorded:
The short-circuit test was performed on the high-voltage side of this transformer bank, and the following data were recorded:
- Find the per-unit equivalent circuit of this transformer bank.
- Find the voltage regulation of this transformer bank at the rated load and 0.90 PF lagging.
- What is the transformer bank’s efficiency under these conditions?
Trending nowThis is a popular solution!
Chapter 2 Solutions
Electric machinery fundamentals
Additional Engineering Textbook Solutions
ELECTRICITY FOR TRADES (LOOSELEAF)
Programmable Logic Controllers
Principles Of Electric Circuits
Principles and Applications of Electrical Engineering
ANALYSIS+DESIGN OF LINEAR CIRCUITS(LL)
Introductory Circuit Analysis (13th Edition)
- 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) Noarrow_forwardThe symbol shown is a(n) a. iron core transformer. b. auto transformer. c. current transformer. d. air core transformer.arrow_forwardFor an ideal transformer, the efficiency is (a) 0 (b) 100 (c) 50arrow_forward
- 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.arrow_forwardA 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.arrow_forwardFor performing dielectric-strength tests on insulating materials, two transformers are connected in a A. parallel combination.B. polyphase arrangement.C. series combination. D. cascade arrangement.arrow_forward
- Three 20-kVA, 24000/277-V distribution transformers are connected in A-Y. The open-circuit test was performed on the low voltage side of this transformer bank, and the following data were recorded: Viine, OC = 480 V ljine, OC = 4.1 A P3p, Oc = 945 W The open-circuit test was performed on the low voltage side of this transformer bank, and the following data were recorded: Viine, sc = 1400 V line, SC = 1.8 A P39. SC = 912 W What is the magnetization reactance of this transformer, XM, in pu?arrow_forwardA single-phase, 240 kVA, 240/4800 V transformer has the parameters shown in Figure Q5. Determine I and V at the primary and secondary when transformer is operating at full load kVA, 0.8 power factor leading and 220 V at the primary side. Find the voltage regulation. Use actual values and per unit system. 0.002625 Q 0.009 0 1.05 Ω 3.6 Ω V2 40 0 30 Q Figure Q5arrow_forward6. The figure below shows a single-line-diagram of part of a power system. For each transformer in the diagram state a suitable connection method, giving reasons for your suggested connection method. G1 G1 800MW 200MW 15kV 10kV T1-T4 88 T5-T6 250MVA each 125MVA each 330/15kV 88/10kV Line 1 Line 2 T7-T8 100MVA each 330/88kV T9 T10-T11 50MVA 50MVA each 88/66kV 88/11kV T12 2MVA 11/0.4kV Singe-phase loadsarrow_forward
- A voltage transformer in Figure 8 has 1,500 turns of wire on its primary winding and 500 turns of wire for its secondary winding. What will be the turns ratio, a of the transformer. If 240 volts is applied to the primary winding, what will be the resulting secondary voltage. And if a 400 n resistor is connected to the secondary winding, what are the values of current Is and Ip. primary Vp Transformer Core NF Ns Figure 8 secondary Vsarrow_forward74. The eddy-current loss in a 6.9 kV, 50 Hz transformer is 220 W. What will be the eddy-current loss of this transformer if it is to be connected across a 6.6 kV, 60 Hz source? A. 201 W C. 234 W B. 224 W D. 212 Warrow_forwardcurrent? Why? 2-6. A 1000-VA, 230/115-V transformer has been tested to determine its equivalent cir- cuit. The results of the tests are shown below. Open-circuit test (on secondary side) Voc = 115 V loc = 0.11 A Poc = 3.9 W Short-circuit test (on primary side) Vsc = 17.1 V 1sc = 8.7 A Psc = 38.1 W (a) Find the equivalent circuit of this transformer referred to the low-voltage side of the transformer. (b) Find the transformer's voltage regulation at rated conditions and (1) 0.8 PF lag- ging, (2) 1.0 PF, (3) 0.8 PF leading. (c) Determine the transformer's efficiency at rated conditions and 0.8 PF lagging.arrow_forward
- Power System Analysis and Design (MindTap Course ...Electrical EngineeringISBN:9781305632134Author:J. Duncan Glover, Thomas Overbye, Mulukutla S. SarmaPublisher:Cengage LearningDelmar's Standard Textbook Of ElectricityElectrical EngineeringISBN:9781337900348Author:Stephen L. HermanPublisher:Cengage Learning