Fundamentals of Energy Systems HW5 Q3 3. Assume that a 20 kVA, 7200/120 V, 60 Hz, single-phase transformer has0.0125+j0.025 pu series impedance.• Find its rated copper loss in watts.• If the core loss is approximately 400 W, find an estimate of its Re in p.u.• If the magnetization current is 0.04 p.u., find an estimate of the magneti-zation reactance Xm in p.u.• Find the values of the series impedance and the magnetization reactancein ohms, referred to the HV side.

Step 1: Given Data: Transformer rating: Srated=20 kVA=20,000 VA Voltage rating: VHV=7200…

Answered: 3. Assume that a 20 kVA, 7200/120 V, 60…

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 3.28MCQ

See similar textbooks

Similar questions

An ideal transformer has no real or reactive power loss. (a) True (b) False
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.
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 250/125 V, five kVA single-phase transformer has a primary resistance of 0.2 ohms and reactance of 0.75 ohms. The secondary resistance is 0.05 ohm and reactance of 0.2 ohms.a) Determine its regulation while supplying full load on 0.8 leading p.f.b) The secondary terminal voltage on full load and 0.8 leading p.f.Ans.: -0.4.88%; 131.1
In a transformer that has 10 times more turns on the secondary side (side 2) than on the primary side (side 1), the magnitude of the voltage/EMF across the windings on the secondary side, E₂ will be... O a.... 10 times lower than the voltage/emf on the primary side, E₁. O b.... the same as the voltage/emf on the primary side. O c.... always zero regardless of the voltage on the primary side, E₁. O d.... 10 times higher than the voltage/emf on the primary side, E₁.
10. In a transformer, the leakage flux of each wind- ing is proportional to the current in that winding because (a) Ohm's law applies to magnetic circuits (b) leakage paths do not saturate (c) the two windings are electrically isolated (d) mutual flux is confined to the core. 11. In a two-winding transformer, the e.m.f.per turn in secondary winding is always.........the induced e.m.f. power turn in primary. (a) equal to K times (b) equal to 1/K times (c) equal to (d) greater than. 12. In relation to a transformer, the ratio 20: 1 indi- cates that (a) there are 20 turns on primary one turn on secondary (b) secondary voltage is 1/20th of primary voltage (c) primary current is 20 times greater than the secondary current. (d) for every 20 turns on primary, there is one turn on secondary.
a) Define what the term "permeability" means. Explain why this is an important parameter in designing transformers. b) A maximum current of 60 A flows in a copper conductor with cross-sectional area, A. u7 ond o recistivity of 20 n0. m. A 250 m cable is being used on a 240 V DC circuit to
I need the answer at 20 minute
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?
Q:A 50 Hz, single phase transformer has a tums ratio of 6.The resistances are 0.9 2 and 0.03 Q and reactances are 5 2 and 0.13 Q for high voltage and low voltage windings respectively.Find : i)The voltage to be applied to high voltage side to obtain full load current of 200 A in the low voltage winding on short circuit. ii) The power factor on short circuit.
Q2) For the linear transformer shown in figure below, find: a) Construct a frequency – domain equivalent circuit of the system b) Calculate the self – impedance of the primary circuit. c) Calculate the self – impedance of the secondary circuit. d) Calculate the impedance reflected into the primary winding. e) Calculate the scaling factor of the reflected impedance. 42 -j62 1:2 ww 120/0° V rms 20 N ll
A 3000/200V ,50hz. , single phase transformer has a cross sectional area of 150 cm2 for the core. If number of turns on the low voltage winding is 80, determine number of turns on the high voltage winding and maximum value of flux density in the core.

SEE MORE QUESTIONS

Recommended textbooks for you

Power System Analysis and Design (MindTap Course …

Electrical Engineering

ISBN:

9781305632134

Author:

J. Duncan Glover, Thomas Overbye, Mulukutla S. Sarma

Publisher:

Cengage Learning