Transmission Line Parameter Calculation

by adminMay 9, 2020May 10, 2020

Transmission line length formula:

$Length=\frac{\sqrt{XB}}{2\Pi f }\times$ the velocity of light in km/s

Now suppose a transmission line parameter data is as follows

R= 0.010 pu, X= 0.085 pu, B=0.176 pu.

The base value of power and voltage is given as

V_{b} = 230 k V, S_{b} = 100 M V A

Then the length is

$Length=\frac{\sqrt{0.085\times0.176}}{2\times3.1416 \times 60} \times(3\times 10^5 km/s)$

Length = 97.33 km

Now we will calculate the resistance value:

$\mathbf{R_{actual}= R_{base}\times R_{pu}}$

$R_{base}= X_{base}= \frac{V_{b}^{2}}{S_{b}} = \frac{(230\times 10^3)^{2}}{100\times 10^6} = 529$

$R_{actual}= 529\times 0.01 = 5.29 \Omega$

$R_{\Omega /km} = R_{actual}/Line Length = 5.29/97.33= 0.0543 \Omega /km$

$Zero Sequence Resistance R_{0}= 0.0543 \times 3 = 0.0163 \Omega / km$

Inductance Value Calculation:

X= 0.085 pu

X_{b a s e} = R_{b a s e} X_{b a s e} = 529 X_{a c t u a l} = 529 \times 0.085 = 44.965 L_{a c t u a l} = \frac{X_{a c t u a l}}{2 πf} = \frac{44.965}{2 \times 3.1416 \times 60} = 0.1192

$X_{base}= R_{base} = 529$

$X_{actual}= 529\times 0.085 = 44.965$

So L actual is 0.1192 Henry

Want to get the value in per kilometer, so we will divide this value by the total length of the transmission line(97.33 km)

L_{H / k m} = \frac{0.1192}{97.33} = 1.225 \times 10^{- 3} H / k m

Zero sequence Inductance will be

L_{0} = 1.225 \times 10^{- 3} \times 3 = 3.676 \times 10^{- 3} H / k m

Capacitor Value Calculation:

In order to find the value of capacitance, first, we have to calculate the value of susceptance which is the reciprocal of

Related

Published by admin

View all posts by admin

Leave a Reply Cancel reply