4.8. A three-phase transposed line is composed of one ACSR 159,000 cmil, 54/19 Lapwing conductor per phase with flat horizontal spacing of 8 meters as shown in Figure 37. The GMR of each conductor is 1.515 cm. (a) Determine the inductance per phase per kilometer of the line. (b) This line is to be replaced by a two-conductor bundle with 8-m spacing mea- sured from the center of the bundles as shown in Figure 38. The spacing between the conductors in the bundle is 40 cm. If the line inductance per phase is to be 77 percent of the inductance in part (a), what would be the GM R of each new conductor in the bundle? - D12 = 8 m D23 = 8 m -D13 = 16 m- %3D FIGURE 37 Conductor layout for Problem 4.8 (a).

4.8. A three-phase transposed line is composed of one ACSR 159,000 cmil, 54/19 Lapwing conductor per phase with flat horizontal spacing of 8 meters as shown in Figure 37. The GMR of each conductor is 1.515 cm. (a) Determine the inductance per phase per kilometer of the line. (b) This line is to be replaced by a two-conductor bundle with 8-m spacing mea- sured from the center of the bundles as shown in Figure 38. The spacing between the conductors in the bundle is 40 cm. If the line inductance per phase is to be 77 percent of the inductance in part (a), what would be the GM R of each new conductor in the bundle? - D12 = 8 m D23 = 8 m -D13 = 16 m- %3D FIGURE 37 Conductor layout for Problem 4.8 (a).

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 4.24P

See similar textbooks

Similar questions

The capacitance of a single-circuit, three-phase transposed line with the configuration shown in Figure 4.38, including ground effect, and with conductors not equilaterally spaced is given by C20lnDeqrlnHmH8 F/mÂ line-to-neutral where Deq=D12D23D133=GMD r= conductors outside radiusHm=(H12H23H13)1/3HS=(H1H2H3)1/3 Now consider Figure 4.39 in which the configuration of a three-phase, single circuit, 345-kV line with conductors having an outside diameter of 1.065 in. is shown. Determine the capacitance to neutral in F/m, including the ground effect. Next, neglecting the effect of ground, see how the value changes.
For the case of double-circuit, bundle-conductor lines, the same method indicated in Problem 4.27 applies with r' replaced by the bundles GMR in the calculation of the overall GMR. Now consider a double-circuit configuration shown in Figure 4.36 that belongs to a 500-kV, three-phase line with bundle conductors of three subconductors at 21 in. spacing. The GMR of each subconductor is given to be 0.0485 ft. Determine the inductive reactance of the line in ohms per mile per phase. You may use XL=0.2794logGMDGMR/mi/phase
A 60-Hz, 765-kV, three-phase overhead transmission line has four ACSR 900 kcmil 54/3 conductors per phase. Determine the 60 Hz resistance of this line in ohms per kilometer per phase at 50C.
Three ACSR Drake conductors are used for a three-phase overhead transmission line operating at 60 Hz. The conductor configuration is in the form of an isosceles triangle with sides of 20, 20, and 38 ft. (a) Find the capacitance-to-neutral and capacitive reactance-to-neutral for each 1-mile length of line. (b) For a line length of 175 mi and a normal operating voltage of 220 kV, determine the capacitive reactance-to-neutral for the entire line length as well as the charging current per mile and total three-phase reactive power supplied by the line capacitance.
A three-phase overhead transmission line is designed to deliver 190.5 M VA at 220 kV over a distance of 63 km, such that the total transmission line loss is not to exceed 2.5 of the rated line MVA. Given the resistivity of the conductor material to be 2.84108-m, determine the required conductor diameter and the conductor size in circular mils. Neglect power losses due to insulator leakage currents and corona.
For either single-phase two-wire line or balanced three-phase three-wire line with equal phase spacing D and with conductor radius r, the capacitance (line-to-neutral) in F/m is given by Can=.
Calculate the capacitance-to-neutral in F/m and the admittance-to-neutral in S/km for the three-phase line in Problem 4.18. Also calculate the line-charging current in kA/phase if the line is 110 km in length and is operated at 230 kV. Neglect the effect of the earth plane.
A 60-Hz, three-phase three-wire overhead line has solid cylindrical conductors arranged in the form of an equilateral triangle with 4-ft conductor spacing. The conductor diameter is 0.5 in. Calculate the positive-sequence inductance in Wm and the positive-sequence inductive reactance in /km.
For a single-phase, two-wire line consisting of two solid cylindrical conductors of same radius, r, the total circuit inductance, also called loop inductance, is given by (in H/m) 2107ln(Dr) 4107ln(Dr) where r=e14r=0.778r
The 100-km, 230-kV, 60-Hz, three-phase line in Problems 4.18 and 4.39 delivers 300 M VA at 218 kv to the receiving end at full load. Using the nominal circuit, calculate the ABCD parameters, sending-end voltage, and percent voltage regulation when the receiving-end power factor is (a) 0.9 lagging, (b) unity, and (c) 0.9 leading. Assume a 50C conductor temperature to determine the resistance of this line.
Transmission line conductance is usually neglected in power system studies. True False
For a completely transposed three-phase line identical conductors, each with GMR denoted DS with conductor distance D12,D23, and D31 give expressions for GMD between phases and the average per-phase inductance.