1. The equivalent circuit impedances of a 20-kVA, 800CV240-V, 60-Hz transformer are to be determined. The open-circuit test and the short-circuit test were performed on the primary side of the transformer, and the following data were taken: Open circuit test Short circuit test (on primary) (on primary) VDC=8000V VS.c=489V IDC=0.214 ISc=2.5A PDC=400W PS.C=240W Find the impedances of the approximate equivalent circuit referred to the primary side, and sketch that circuit. 2. Based on the following Simulink model, answer the following questions: Contu Ror Gee Ge Ga 616 Man Auitay wneng aue me vetag e t Singe a Aspone e Spe sumgca Promd LN Vo L Cre (a) For which type of single phase induction motors does this circuit represent? (b) Explain the purpose of C1 in induction motors? (c) How to reverse the direction of rotation of this motor ? (d) When we use this type of single phase induction motors ?

1. The equivalent circuit impedances of a 20-kVA, 800CV240-V, 60-Hz transformer are to be determined. The open-circuit test and the short-circuit test were performed on the primary side of the transformer, and the following data were taken: Open circuit test Short circuit test (on primary) (on primary) VDC=8000V VS.c=489V IDC=0.214 ISc=2.5A PDC=400W PS.C=240W Find the impedances of the approximate equivalent circuit referred to the primary side, and sketch that circuit. 2. Based on the following Simulink model, answer the following questions: Contu Ror Gee Ge Ga 616 Man Auitay wneng aue me vetag e t Singe a Aspone e Spe sumgca Promd LN Vo L Cre (a) For which type of single phase induction motors does this circuit represent? (b) Explain the purpose of C1 in induction motors? (c) How to reverse the direction of rotation of this motor ? (d) When we use this type of single phase induction motors ?

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 3.9P

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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
A single-phase l0-kVA,2300/230-volt,60-Hz two-winding distribution transformer is connected as an autotransformer to step up the voltage from 2300 to 2530 volts (a) Draw a schematic diagram of this arrangement, showing all voltages and currents when delivering full load at rated voltage. (b) Find the permissible kVA rating of the autotransformer if the winding currents and voltages are not to exceed the rated values as a two-winding transformer. How much of this kVA rating is transformed by magnetic induction? (C) The following data are obtained from tests carried out on the transformer when it is connected as a two-winding transformer: Open-circuit test with the low-voltage terminals excited: Applied voltage =230V, input current =0.45A, input power =70W. Short-circuit test with the high-voltage terminals excited: Applied voltage =120, input current =4.5A, input power =240W. Based on the data, compute the efficiency of the autotransformer corresponding to full load, rated voltage, and 0.8 power factor lagging. Comment on why the efficiency is higher as an autotransformer than as a two-winding transformer.
In developing per-unit circuits of systems such as the one shown in Figure 3.10. when moving across a transformer, the voltage base is changed in proportion to the transformer voltage ratings. (a) True (b) False
Find the elements of the equivalent circuit relative to the secondary of a single-phase transformer. The no-load voltages in the primary and secondary circuit are 200 and 400 volts, respectively, and at a frequency of 50 Hz. The primary no-load current at a voltage of 200 volts is 0.7 amps and the losses in the core are 70 watts. The resistance and reactance of the primary are 3.2 and 1.25 ohms, respectively. Secondary resistance and reactance 6.0, 0.07 ohms, respectively. Draw the equivalent circle, showing the values of its elements.
Find the elements of the equivalent circuit relative to the secondary of a single-phase transformer. The no- load voltages in the primary and secondary circuit are 200 and 400 volts, respectively, and at a frequency of 50 Hz. The primary no-load current at a voltage of 200 volts is 0.7 amps and the losses in the core are 70 watts. The resistance and reactance of the primary are 3.2 and 1.25 ohms, respectively. Secondary resistance and reactance 6. 0, 0.07 ohms, respectively. Draw the equivalent circle, showing the values of its elements.
The circuit for a 20-kVA, 220/3960 V, 50-Hz transformer is shown in Figure (1). The open- circuit test and the short-circuit test was performed on this transformer and the following data were taken: Open-Circuit test: Voc=240 V, Ioc=2.8 A, Poc=260 W Short-Circuit test: Vsc = 350 V, Isc=7.6 A, Psc = 420 W 1) Find the values of Rc, XM, Rp and Xs for this transformer. 2) Find the equivalent circuit of this transformer referred to the high-voltage side and draw the circuit. j 0.163 Q jXM 0.02 02 jXs
What are the objectives of implementing an open circuit test on single phase transformer?
The equivalent circuit impedances of a 20-kVA, 8000/240-V, 60-Hz transformer are to be determined. The open-circuit test and the short- circuit test were performed on the primary side of the transformer, and the following data were taken: Open-circuit test (on primary) Short-circuit test (on primary) 8000 V V= 489 V I0.214 A 2.5 A P= 400 W P= 240 W Find the impedances of the approximate equivalent circuit referred to the primary side, and sketch the circuit.
Find the elements of the equivalent circuit attributed to the secondary of a single-phase transformer. The no-load voltages in the primary and secondary circuit are 200 volts and 400 volts, respectively, with a frequency of 50 Hz. The primary no-load current at the voltage of 200 volts is 0.7 amperes and the loss of the core is equal to 70 watts. The resistance and reactance of the primary are 3.2 ohms and 1.25 ohms, respectively. The resistance and reactance of the secondary are 0.6 ohm and 0.07 ohm, respectively. Draw the equivalent circle, showing the values of its elements.
In the single-phase, three- winding, transformer, the primary current is equal to lo at the condition of ints there is no load on tertiary windings the current in secondary windings equal to zero the resistances (R1, R2, and R3) in transformer windings are equal the inductances (L1, L2, and L3) in transformer windings are equal.
Two transformers A and B have the following data Transformer A: 6600/440 V, (250 KVA ) requires ( 6%) of rated voltage to circulate (90%) of full load current at power factor (0.25) when the low voltage winding is short circuited and the no load loss is equal to (2500 W). Transformer B: 6600/420 V, (600 KVA) requires (9%) of rated voltage to circulate (80%) of full load current at power factor (0.16) when low voltage winding is short circuited and no load loss is equal to (4500 W). Calculate the followings: If both transformers are connected in parallel to supply a load (1.2 + j 2.3) ohm, find the output power of each transformer.
Two transformers A and B have the following data Transformer A: 6600/440 V, (250 KVA ) requires ( 6%) of rated voltage to circulate (90%) of full load current at power factor (0.25) when the low voltage winding is short circuited and the no load loss is equal to (2500 W). Transformer B: 6600/420 V, (600 KVA) requires (9%) of rated voltage to circulate (80%) of full load current at power factor (0.16) when low voltage winding is short circuited and no load loss is equal to (4500 W). Calculate the followings: The terminal voltage when transformer A is supplying half load at power factor (0.6) lagging and transformer B is supplying (85%) of full load at power factor (0.85) leading.