ECE-476: Fall 2008
HOMEWORK #4
Due Date: Thursday September 25, 2008
Problems 4.34, 4.35, 5.14 and 5.26 of Power System Analysis and Design textbook
4.34) Calculate the capacitance-to-neutral in F/m and the admittance-to-neutral in S/km for the
three-phase line in Problem 4.10. Neglect the effect of the earth plane.
Problem 4.10) 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.
Conductor diameter is 0.5 in. Calculate the positive-sequence inductance in H/m and the
positive-sequence inductive reactance in
Ω
/km.
4.35) Rework Problem 4.34 if the phase spacing is:
a) Increased by 20% to 4.8 ft.
b) Decreased by 20% to 3.2 ft.
Compare the results with those of Problem 4.34.
5.14) A 500-km, 500-kV, 60-Hz uncompensated three-phase line has a positive-sequence series
impedance z=0.03+j0.35 Ω/km and a positive-sequence shunt admittance y=j4.4 x 10-6
S/km. Calculate:
(a) Zc
(b) (
γ
l)
(c) The exact ABCD parameters for this line.
5.26) A 320-km 500-kV, 60-Hz three-phase uncompensated line has a positive-sequence series
reactance x=0.34 Ω/km and a positive-sequence shunt admittance y=j4.5 x 10-6 S/km.
Neglecting losses, calculate:
(a) Zc
(b) (
γ
l)
(c) The exact ABCD parameters for this line.
(d) The wavelength
λ
of the line, in kilometers.
(e) The surge impedance loading in MW.