Determine the equivalent impedances circuit referred to the primary side of a 20- kVA, 8000/240 V, 60 Hz transformer. The open circuit test was performed on the secondary side and the short circuit test was performed on the primary side. (on secondary) Open-circuit test Short-circuit test (on primary) Voc = 240 V VSC = 489 V loc = 7.133 A Isc = 2.5 A Voc = 400 W Psc = 240 W

Determine the equivalent impedances circuit referred to the primary side of a 20- kVA, 8000/240 V, 60 Hz transformer. The open circuit test was performed on the secondary side and the short circuit test was performed on the primary side. (on secondary) Open-circuit test Short-circuit test (on primary) Voc = 240 V VSC = 489 V loc = 7.133 A Isc = 2.5 A Voc = 400 W Psc = 240 W

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 3.54P: An infinite bus, which is a constant voltage source, is connected to the primary of the...

See similar textbooks

Similar questions

In order to avoid difficulties with third-harmonic exciting current, which three-phase transformer connection is seldom used for step-up transformers between a generator and a transmission line in power systems. (a) Y- (b) -Y (c) Y-Y
How many transformers are needed to make an open-delta connection?
the results of an open circuit and a short circuit test at rated frequency on a 500kVA, 42kV/2.4 kV, 60Hz single-phase transformer, with the following results: open circuit test, on the low voltage side Voc=2400V, Ioc= 18.1A, Poc=3785w. circuit test, on the low voltage side Vsc=1910 V, Isc=11.9A, Psc=3850 W. a) find the approximate equivalent circuit referred to the low voltage with the magnetizing branch independent of the short-circuit impedance b) Find the single-phase equivalent circuit in per unit referred to the high voltage side
Which termination would result to a phase change of 180 degrees at the load if Zo = 100 ohm? a. 50 ohm b. short circuit c. 75 ohm d. all of these What is the purpose of impedance matching? a. maximum return loss b. maximum SWR c. maximum load power d. maximum reflection A short piece of transmission line that may be open or shorted and used for impedance matching purposes. a. converter b. decoder c. stub d. transformer
Q2: A 5kVA, 200/400V, 50Hz single phase transformer gave the following test figures: No-load: (Low-voltage data): 200V, 60W, 0.7A. Short-circuit:(high-voltage data): 9V, 6A, 21.6W. Calculate: a/ the magnetizing current and the component corresponding to iron loss at normal voltage and frequency. b/ the efficiency on full load at unity power factor. c/ the secondary terminal voltage on full load at power factor of unity, 0.8 lagging and 0.8 leading
The 240 kV transmission line is intended to be connected to a 220 kV transmission system through an autotransformer. The single-phase transformer that is available to make the connection is 120 MVA and 240kV/20kV Draw the connection of this autotransformer and show on the same diagram: The magnitude of the input and output voltages of the autotransformer (Magnitude and polarity)Currents and in the windings (magnitude and direction)The voltages in the windings (magnitude and polarity)The input and output currents of the autotransformer (magnitude and direction)Calculate the power capacity of this autotransformer
A100KVA, 6.6KV/300V, 50hz, the 1-phase transformer had the following figures in the short circuit test done on the HV side: 10A, 436 W at 100V. Calculate the voltage to be applied to the HV side on full load at pf 0.8 lagging when the secondary terminal voltage is 330 V.
Three of a 15 kVA, 2200:220 V, 50 Hz transformer are connected in ∆-∆ to supply at 220 Voltsline-to-line a three-phase induction motor load of 20 kVA. The power factor of the induction motor is0.85. The load is connected to the transformers by means of a common three-phase feeder whoseimpedance is 0,03+j0,06 Ω/phase. The transformers themselves are supplied from a constant-potentialsource by means of a three-phase feeder whose impedance is 2,5+j6,0 Ω/phase. The equivalentimpedance ((R''1+R2)+j(X''ℓ1+Xℓ2)) of one transformer referred to the low-potential side (secondary) is0,4+j0,5 Ω/phase. The magnetizing inductance and the resistance representing the core loss areneglected. Calculate the required source line voltage (Vs) if the load line voltage is 220 Volts.Hint: ZY = (1/3)Z∆
3. A three-phase Y-Y transformer is rated at 25 MVA, 13.8-kV:69-kV and has a single-phaseequivalent series impedance 62 + j388 mΩ referred to the low-voltage winding.a. A three-phase short circuit is applied to the low-voltage winding. Calculate the voltage applied to thehigh-voltage winding which will result in rated current into the short circuit.b. The short circuit is removed and a three-phase load is connected to the low-voltage winding. Withrated voltage applied to the high-voltage winding, the input power to the transformer is observed tobe 18 MW at 0.75 power-factor lagging. Calculate the line-line terminal voltage at the load.
The results of open-circuit test and short-circuit test for a 60 kVA , 2400/500 V single phase transformer is given below: Voltage Current Power Open Circuit Test (LV side measurement) 450V 2.5A 500W Short Circuit Test (HV side measurement) 50V 25A 800W Determine: 1. the equivalent core loss resistance and magnetizing reactance referred to HV side; 2. the equivalent winding resistance and flux leakage reactance referred to HV side; 3. the voltage regulation at full-load and power factor of 0.85 lagging 4. the maximum efficiency
The following data were obtained on a 2.5 MVA, 50-Hz, 19.1-kV:3.81-kV single-phase transformertested at 50 Hz:Voltage (V) Current (A) Power (kW)LV winding with HV terminals open-circuited: 3810 9.86 8.14HV winding with LV terminals short-circuited: 920 141 10.3a. Calculate the cantilever equivalent-circuit parameters as referred to the transformer high-voltagewinding.b. Calculate the cantilever equivalent-circuit parameters as referred to the transformer low-voltagewinding.c. With the transformer carrying rated load and rated voltage at its low-voltage terminal, calculate thepower dissipated in the transformer.d. Repeat part a and b in per-unit. Compare and comment on your result.
A 3-phase, 6,600/415-V, 2,000-kVA, delta-wye connected transformer has a primary impedance of of 5+ j 4.5 ohms and secondary impedance of 0.02 + j 0.45 ohms per phase. Calculate the Cu loss and the percent voltage regulation at full-load 0.8 p.f.