Q4/For the three-phase power network shown in Figure. the various components are: GI: 100 MVA, 0.30 pu reactance. G2: 60 MVA, 0.18 pu reactance. Transformers (each): 50 MVA, 0.10 pu reactance. Inductive reactor X: 0.20 pu on a base of 100 MVA. Lines (each): 80 ohms (reactive); neglect resistance. with the network initially unloaded and a line voltage of 110 kV, a symmetrical short circuit occurs at midpoint E of line 2. Calculate the short circuit MVA to be interrupted by the circuit breakers A and B at the ends of the line. TI LI L2 G2 Bus T2 T4 Bus

Q4/For the three-phase power network shown in Figure. the various components are: GI: 100 MVA, 0.30 pu reactance. G2: 60 MVA, 0.18 pu reactance. Transformers (each): 50 MVA, 0.10 pu reactance. Inductive reactor X: 0.20 pu on a base of 100 MVA. Lines (each): 80 ohms (reactive); neglect resistance. with the network initially unloaded and a line voltage of 110 kV, a symmetrical short circuit occurs at midpoint E of line 2. Calculate the short circuit MVA to be interrupted by the circuit breakers A and B at the ends of the line. TI LI L2 G2 Bus T2 T4 Bus

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

The section bus-bars A and B are linked by a bus-bar reactor rated at 6000 kVA with 12% reactance. On bus-bar-A, there are two generators each of 10 MVA with 8% reactance and on bus-bar-B, two generators each of 6000 kVA with 10% reactance. Find the steady MVA fed into a dead short circuit all phases on B with bus-bar reactor in the circuit.
What is the main direct cause of reactive power in AC system?A. Resistance of transmission linesB. Inductance and capacitance in the loadsC. Ideal transformer connected in the systemD. Power produced by generator
Which of the following statements is/are true? (A In purely inductive circuit, the current leads voltage. (B) In purely resistive circuit, the current lags voltage. C In purely resistive circuit, the current is in phase with voltage. D In purely capacitive circuit, the voltage lags current.
Problem 1 - Series en Parallel AC networks [19] Look at the circuit in Figure 1 and determine the following: (a) Total Admittance. (b) Total Impedance. (c) Total Current (l:). (d) Current (I1) through impedance Z2. (e) Current (12) through impedance Z3. (f) Current (I3) through impedance Z4. (g) Is this an inductive or capacitive circuit? A. B Zs 220V;50HZ Figure 1 (h) Voltage across Z1. (i) Voltage across A and B. G) Voltage across Zs. Z1 = 3 + j5 ohm Z2 = 10 + jo ohm Z3 = 5 + j15 ohm Z4 = 10 – j30 ohm Zs = 20 – j30 ohm Admittance and Impedance in rectangular notation. All currents and voltage in polar notation. Take voltage as reference.
Consider a 3-phase, 50 HZ, 11 KV distribution system. Each of conductors is suspended by an insulator string having two identical porcelain insulators. The self-capacitance of the insulator is 5 times the shunt capacitance between link and ground. Find the voltages across two insulators.
The p.u. impedance value of an alternator corresponding to base values of 13.2 kV and 30 MVA is 0.2 p.u. Then the p.u. impedance value of an alternator for the new base values of 13.8 kV and 50 MVA is......
Which of the following statements is/are true? A In purely resistive circuit, the current lags voltage. (B In purely capacitive circuit, the voltage lags current. In purely resistive circuit, the current is in phase with voltage. D In purely inductive circuit, the current leads voltage.
Q20. The section bus-bars A and B as shown in Figure B5 are linked by a bus-bar reactors each rated at 5000 kVA with 10% reactance. On bus-bar A, there are two generators each of 10,000 kVA with 10% reactance and on B two generators each of 8000 kVA with 12 % reactance. Find the Current and MVA that fed into a dead short circuit between all phases on B with bus-bar reactor in the circuit. Page 4 of 5 جامعة التقنية والعلومر التطبيقية بإبراء University of Technology and Applied Sciences - Ibra Student ID: Section: Student Name: 8,000 kVA 12% 10,000 kVA 10,000 kVA 10% 8,000 kVA 12% 10% 2 3 5,000 kVA 10% lell 8,000 kVA 10% Figure B5 "End of Question Paper"
7. TY Hat CHICL Ans. 1. Iron los.........varies approximately as V². 2. Cu loss..........it also varies as ² but decreases with an increase in voltage if constant kVA output is assumed. 3. Efficiency...........for distribution transformers, efficiency at fractional loads decreases with in- crease in voltage while at full load or overload it increases with increase in voltage and vice- versa. 4. Regulation..........it varies as but decreases with increase in voltage if constant kVA output is assumed. 5. Heating.........for constant kVA output, iron temperatures increase whereas Cu temperatures decrease with increase in voltages and vice-versa. quems
What effects are produced by change in voltage? 1. Iron los..........varies approximately as V². 2. Cu loss..........it also varies as V² but decreases with an increase in voltage if constant kVA output is assumed. 3. Efficiency...........for distribution transformers, efficiency at fractional loads decreases with in- crease in voltage while at full load or overload it increases with increase in voltage and vice- versa. 4. Regulation..........it varies as but decreases with increase in voltage if constant kVA output is assumed. 5. Heating.........for constant kVA output, iron temperatures increase whereas Cu temperatures decrease with increase in voltages and vice-versa.
Discuss Fully the various methods available for transforming 3-phase voltages to higher or lower 3-phase voltages. Highlight the advantages and disadvantages of each. Include the connection diagrams.
A parallel connection of a RL branch with a C branch is connected across a 100V AC mains. At first R = 10 ohms, L = 20mH and frequency of 1000rad / s, the current measured is 2.2361A at 89.44 leading power factor. A) Determine the initial capacitance. B) However, a fault occurs on the capacitor branch making its capacitance 20% lower and a resistance of 5 ohms is detected. If this faulty circuit is rerun but at a frequency of 500 rad / s, determine the new current that will flow through the circuit