Chapter 2: Calculation of Line and Ground Parameters
1. A long transmission line has the following parameters per phase: series impedance Z =
0.997 79.270Ω/km and shunt admittance Y = 4.52 Ʊ/km. Calculate
a. Propagation constant
b. Attenuation constant
c. Wave length
d. Velocity of propagation.
2. Obtain an expression for the GMR of a bundled conductor with usual notations.
3. The line conductors of a 3 phase 400 kV, horizontal line are arranged horizontally with a
phase separation of 11 m and are mounted at a height of 15 m above the ground level.
The conductor dimensions are 2 X 3.18 cm dia and B = 45.72 cm. Obtain the inductance
matrix for both transposed and untransposed conditions.
4. With usual notations, obtain an expression for the inductance of a bundled conductor
mounted at a height of H mtrs above the ground.
5. A 345-kV line has an ACSR Bluebird conductor 0.04477m indiameter with an equivalent
radius for inductance calculation of 0.0179 m. The line height is 12m. Calculate the
inductance per km length of conductor and the error caused by neglecting theinternal flux
linkage.
6. The dimensions of a 3-phase 400-kV horizontal line are:H = 15 m, S = 11 m phase
separation, conductor 2 × 3.18 cm dia, and B = 45.72 cm. Calculate.(a) theinductance
matrix of per km, for untransposed. (b) the capacitance matrix.
7. Diagonalize the matrix D given below and also give eigen values and eigen vector
matrices.
1 1 1
[ ]= 1 1 1
1 1 1
8. The inductance matrix for a transposed line is given by
[ ]=
Obtain the diagonalization of [ ] by evaluating suitable
transformation matrix [ ] and its inverse [ ]
9. The
[ ]=
a.
b.
c.
capacitance matrix of a 750-kV
10.2 −1.45 −0.35
−1.45 10.4 −1.45
−0.35 −1.45 10.2
Find the 3 eigen values of the matrix
Diagonalize the matrix
0 0
0
Prove that [ ] [ ][ ] = 0
0 0
horizontal
10. Explain the inductance effect on
a. Round conductor with internal and external flux linkages
b. Flux linkage calculation of 2 – conductor line.
configuration
line