QUESTION 2 [15 marks] Assume a long transmission line depicted on figure 2 is operated on no-load condition. If bc1 = bc2 91 92 and bc1 = 292, a. give expressions for sending end voltage and any six currents that could possibly flow in the network b. sketch a labelled phasor diagram to relate the condition of the line χ bc2 92 bc1 91 Vs figure 2 QUESTION 3 [15 marks] A 50Hz, overhead single-phase, short transmission line delivers 880 + j660 kVA at 33kV. Assume a total line impedance per phase of 18.03 < 56.30 and : a. sending end voltage b. sending end power and power factor angle c. transmission efficiency d. Compute the load impedance, line inductance and capacitance

QUESTION 2 [15 marks] Assume a long transmission line depicted on figure 2 is operated on no-load condition. If bc1 = bc2 91 92 and bc1 = 292, a. give expressions for sending end voltage and any six currents that could possibly flow in the network b. sketch a labelled phasor diagram to relate the condition of the line χ bc2 92 bc1 91 Vs figure 2 QUESTION 3 [15 marks] A 50Hz, overhead single-phase, short transmission line delivers 880 + j660 kVA at 33kV. Assume a total line impedance per phase of 18.03 < 56.30 and : a. sending end voltage b. sending end power and power factor angle c. transmission efficiency d. Compute the load impedance, line inductance and capacitance

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

Chapter4: Transmission Line Parameters

Section: Chapter Questions

Problem 4.8P: A 60-Hz, single-phase two-wire overhead line has solid cylindrical copper conductors with a 1.5 cm...

See similar textbooks

Similar questions

A dc two line distributor AB 600 metre long is fed at 440 V from substation A and at 430 V from substation B, the load are: 100 A at C (150 m from A), 200 A at D (150 m from C), 250 A at E (50 m from D), 300 A at F (100 m from E). If each line conductor has a resistance of 0.01 ohm per 100 m, calculate the current supplied from substation A and B and the voltage across each load.
Question 1) A 154 kV transmission line has a length of 100 km. The line and the conductors are given in Figure 1. The line is operated at f= 50 Hz. For both old and new lines calculate; a. GMD and GMR. b. Inductance of the line in Henries (H). c. Series Impedance (Z) of the line in Ohms. d. *Compare the results for both lines and comment on the results. e. *If the distance between the two neighbouring conductors is increase from 13 meters to 15 meters what would be the parameters in part a.,b. and c. comment on the results. New Line's Conductors 13 m 13 m Old Line's Conductors d r = 2 cm d = 40 cm r = 2 cm Figure 1
Figure Q2 (a) shows the spacing of a double circuit 3-phase overhead line. The phase sequence is RYB and the line is completely transposed. i) Critically assess the significance of transposition in a 3-phase overhead line. ii) Calculate the inductance per phase for 500 meter length of line using Table 2(a) data for the Figure Q2(a). Table 2(a) GMR of the line Distance a-b' 0.01m 6.6m Distance a-a' 8.5m Figure Q2(a)
Overhead transmission-line conductors are bare with no insulating cover. (a) True (b) False
A 60-Hz, single-phase two-wire overhead line has solid cylindrical copper conductors with a 1.5 cm diameter. The conductors are arranged in a horizontal configuration with 0.5 m spacing. Calculate in mH/km (a) the inductance of each conductor due to internal flux linkages only, (b) the inductance of each conductor due to both internal and external flux linkages, and (c) the total inductance of the line.
Alumoweld is an aluminum-clad steel conductor. True False
In a three-phase line, in order to avoid unequal phase inductances due to unbalanced flux linkages, what technique is used?
1 9:17 decreased Q3: The shunt admittance of a transmission line is 3 microsiemens. Its complex notation will be .siemen. 3 x 10- 6 2270° Q4: Now-a-days system is used for transmission line * Choose AC ,DC AC DC No any of the answers above Q6:For voltages beyond 66 kV, 3-phase system usually employs. II
14
a.Why does power plants have high amounts of voltages? Explain. b.Is it safe for transmission lines to have high current instead of high voltage? Why? c.What phenomenon is avoided by having separations between three conductor phases? Explain this phenomenon.
Discuss the desirable properties of insulators. Explain the causes of insulator failure due to electrical breakdown. Each line of a three-phase system is suspended by a string of three identical insulators of self-capacitance C farad. The shunt capacitance of connecting metal work of each insulator to earth is 20.7 % of C while for line it is 13.8 % of C. Calculate the string efficiency of the system if a guard ring increases the capacitance to the line of metal work of the lowest insulator to 0.25 C.
5) Choose the correct answer with the explain: a) The maximum power transferred to the load is satisfied at, 1. ZL=0 2. ZL=00 3. ZL=Zo b) For a certain transmission lines, if l-50m and ta2-400nsec, then Vp will equal to: 1. 125*106 m/sec 2. 250*106 m/sec 3. 500*106 m/sec c) The minimum and maximum values of the reflection coefficients are, 1. O and 1 2. 0 and infinity 3. -1 and 1 d) For a certain transmission line, Zo=2002, l=200m. if I changes to 100m, then Zo will be: 1. 502. 2. 1002. 3. 2002.