(a) A 5 MVA 230/10.5-kV single-phase power transformer has a per-unit resistance of 1.5% and a per-unit reactance of 6% (data taken from the transformer's nameplate). The transformer approximate equivalent circuit is given in Figure Q1 (a). The open-circuit test performed on the low-voltage side of the transformer yielded the following data: Voc = 120 kV loc = 10 A Poc = 60 kW %3D %3D %3D Refer to the low-voltage side of the transformer and calculate: (i) The value of Req and Xeq. (ii) The value of Rc and Xm.

(a) A 5 MVA 230/10.5-kV single-phase power transformer has a per-unit resistance of 1.5% and a per-unit reactance of 6% (data taken from the transformer's nameplate). The transformer approximate equivalent circuit is given in Figure Q1 (a). The open-circuit test performed on the low-voltage side of the transformer yielded the following data: Voc = 120 kV loc = 10 A Poc = 60 kW %3D %3D %3D Refer to the low-voltage side of the transformer and calculate: (i) The value of Req and Xeq. (ii) The value of Rc and Xm.

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 3.16P: A single-phase, 50-kVA,2400/240-V,60-Hz distribution transformer has the following parameters:...

See similar textbooks

Similar questions

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
An ideal transformer has no real or reactive power loss. (a) True (b) False
The ideal transformer windings are eliminated from the per-unit equivalent circuit of a transformer. (a) True (b) False
Why is it important to reduce the moisture within a transformer to acceptable levels during transformer installation?
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 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.
The symbol shown is a(n) a. iron core transformer. b. auto transformer. c. current transformer. d. air core transformer.
What conclusions we come up with after doing open circuit test on single phase transformer.
Draw the equivalent circuit for a single-phase transformer with all the components referred to the primary side. Give a brief description of what each circuit component represents, and indicate how the secondary voltage and current are subsequently calculated from the primary side values.
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.
A transformer has primary and secondary turns of 1250 and 125 respectively. It has core cross-sectionof 36 cm2 and its rms flux density is to be limited to 1.4 T (to prevent core saturation). Whatmaximum 50 Hz voltage can be applied on the primary side and the corresponding open-circuitsecondary voltage?The core has a mean length of 150 cm and its relative permeability can be assumed to be 8000. Whatwould be the rms exciting current when the transformer’s primary winding is excited at a voltage ascalculated above? Also calculate the magnetizing susceptance as seen from primary and secondarysides.If the transformer were to be excited at 60 Hz, 1. What should be the maximum primary voltage for thecore flux density limit not to be exceeded? 2. What would be the magnetizing susceptance as seen oneach side in this case?