A simple power system is shown in this Fig. The generator (480 V, 10 kVA) is connected to an ideal step-up transformer (1:20), a transmission line (R=20 Ohm and X=60 Ohm), step down transformer (40:1) and a load (R= 25 Ohm and X=10 Ohm) the base values for this system are chosen to be 480 V and 10 kVA at the generator. Calculate the per unit reactive power for the load. line oad Zoad 202 j60 N Zine 480 0° V 6-Per-unit Systems Calculations.pdf - Adobe Acrobat Reader DC (32-bit) Select one: O a. 0.079 O b. 1.63 O c. 1.33 O d. None of the above O e. 0.25

A simple power system is shown in this Fig. The generator (480 V, 10 kVA) is connected to an ideal step-up transformer (1:20), a transmission line (R=20 Ohm and X=60 Ohm), step down transformer (40:1) and a load (R= 25 Ohm and X=10 Ohm) the base values for this system are chosen to be 480 V and 10 kVA at the generator. Calculate the per unit reactive power for the load. line oad Zoad 202 j60 N Zine 480 0° V 6-Per-unit Systems Calculations.pdf - Adobe Acrobat Reader DC (32-bit) Select one: O a. 0.079 O b. 1.63 O c. 1.33 O d. None of the above O e. 0.25

Introductory Circuit Analysis (13th Edition)

13th Edition

ISBN:9780133923605

Author:Robert L. Boylestad

Publisher:Robert L. Boylestad

Chapter1: Introduction

Section: Chapter Questions

Problem 1P: Visit your local library (at school or home) and describe the extent to which it provides literature...

See similar textbooks

Similar questions

An ideal auto-transformer has its secondary winding labelled as a, b and c. The primary winding has 100 turns. The number of turns on the secondary side are 400 turns between a and b and 200 turns between b and c. The total number of turns between a and c is 600 turns. The transformer supplies a resistive load of 6 kW between a and c. In addition, a load of impedance 1,000 cis (45°) ohms is connected between a and b. For a primary voltage of 1,000 V, find the primary current and primary input power.
generator (b) What is the average power dissipated in R? P=[ W Help Enter 500 v generator voltage -500 v AC Generator 0 Ideal Transformer R = 300 Rg8 time (a) The sinusoidal voltage output from the AC generator oscillates between 500 V and -500 V. The circuit for an ideal transformer is constructed with a generator, transformer and a 30 W resistor. The generator makes 6 loops with the transformer and the resistor makes 11 loops with the transformer (the figure does not show these loops accurately). What is the maximum voltage across the resistor R? V= V Help Enter
Approximate solution time is 5 minutes. A transformer supplies power to a feeder that has five customers. Daily maximum demands for these customers are 120 kW, 40 kW, 90 kW, 110 kW, and 180kW. The maximum demand on the feeder is 243kW. The coincident factor of the feeder is
Question2 Consider a 4 kVA, 200/400 V single-phase transformer supplying 80%load current at 0.8 leading power factor. The O.C./S.C. test results are as follows: O.C. test: 200 V, 0.8 A, 70 W (LV. side) S.C. test : 20 V, 10 A, 60 W (H.V. side) Calculate efficiency, secondary voltage and current into prinary at the above load.
The O.C of a 5 kVA 200/400 V transformer. In the test, 72 W of power was used, supplying 200 V to the transformer. S.C. In the test, full load current was passed through the secondary supplying 8 V to the primary and taken from a power supply of 80 W. Find the full load efficiency at a power factor of 0.8.
The primary of a current transformer takes 1 A at a power factor of 0.4 when it is connected across a 200-V, 50Hz supply and the secondary is on open circuit. The number of turns on the primary is twice that on the secondary. A load taking 50 A at a lagging power factor of 0.8 is now connected across the secondary. What is now the value of primary current?
Q5-(A)- The all-day efficiency 200 KVA transformer is 96% when it is loaded follows 12 hours 120 k w at p.f. 0.8 lag 15.3 8 hours 80kw at p.f. 0.8 lag 4 hours No load 46.616 559.39 If maximum efficiency of this transformer is 96.8% at 80% of load with unity p.f. Find iron loss and full load copper loss
Q2: A 1OKVA distribution transformer has a full.load e fficiency at 0-85 p.f of 95/ the ca ppes and van losses then being equal. Caleulote its all- day efficiency through out the 24 hours if it is loaded as follows Neload Quarter lod lo hours 5 hours 子 howe 2 heurs load Pf .f 0.9 half load full load Assums
Q2/A/ What are the conditions for satisfying parallel operation of single phase transformer? Deduce an expression for the load shared by the two transformers in parallel when the transformers have equal voltage ratio? Prove your answer. B/ A 50 KVA, 2300/230 V, 60 11z transformer has a high voltage winding resistance of 0.650 and a low-voltage winding resistance of 0.0065 2. Laboratory tests showed the following results: Open circuit test: V = = 230 V, I =5.7A, P = 190 W Short circuit test: V-41.5 V, I-21.7 A, P-No wattmeter was used. 18 (2) Compute the value of primary voltage needed to give rated secondary voltage when the transformer is connected as a step-up one and is delivering 50 KVA at a power factor of 0.8 lagging. (b) Compute the efficiency under conditions of part (a).
A 100kVA transformer has a maximum efficiency of 0.95 at 50% full load and unity power factor . During a day , it is loaded as follows : 100kVA at unity p.f for 8hours , 50kVA at 0.8p.f. for 6hours, and no load for 10hours. Determine its all day efficiency .
A 100 kVA, 400 V/250 kV testing transformer has 8% leakage reactance and 2% resistance on 100 kVA base. A cable has to be tested at 500 kV using the above transformer as a resonant transformer at 50 Hz. If the charging current of the cable at 500 kV is 0.4 A, find the series inductance required. Assume 2% resistance for the inductor to be used and the connecting leads. Neglect dielectric loss of the cable. What will be the input voltage to the transformer?
Q4//a. A 600 KVA one phase transformer when working at unity p.f has an efficiency of 92% at full load and also at half full load. Determine its efficiency when it operates at unity p.f and 60% of full load. b. The voltage in an alternating current circuit at any time t seconds is given by v=60 sin 40 t volts. Find the first time when the voltage is (i)50 v (ii)15 v