FORMULAS
USED:
Single phase
Inductance=10^-7[1+4log (d/r)]
Capacitance=3.14*8.854*10-12/log
(d/r)
Three phase
Inductance=10^-7 [0.5+2log (d/r)]
Capacitance=2*3.14*8.854*10-12
/log (d/r)
Dequivalent =
[d1*d2*d3]1/3
Where
d=Spacing of conductors
r=radius of
conductor
An AC transmission line has resistance,
inductance and capacitance uniformly distributed along its length. These are
known as constants or parameters of the line. The performance of a transmission
line depends to a considerable extent upon these constants. For instance, these
constants determine whether the efficiency and voltage regulation of the line
will be good or poor. Therefore, a sound concept of these constant is necessary
in order to make the electrical design of a transmission line a technical
success. Constants of transmission line are resistance, inductance and
capacitance uniformly distributed along the whole length of the line.
RESISTANCE:
It is the opposition of line conductors to
current flow. The resistance is distributed uniformly along the whole length of
the line.
INDUCTANCE:
An alternating current flows throw a
conductor, a changing flux is setup which links the conductor. Due to this flux
linkage, the conductor possesses inductance. Inductance defined as the flux
linkage per ampere.
CAPACITANCE:
The capacitance between the conductors is
the charge per unit potential difference.
MATLAB CODING
clear all
clc
disp(‘-------------------------MATLAB
PARADISE---------------------’)
%%Coding extracted from
howtousematlab.blogspot.com%%
ph=input('single-1or 3ph-3:-')
if ph==1
D=input('Distance between cond in mtrs=')
R=input('Radius_cond in mtrs=')
L=(10^(-7)*(1+4*log(D/R)))
C=((pi*(8.854*10^(-12))))/log(D/R)
else
if ph==3
spacing=input('Symmetrical-4 Unsymmetrical-5:')
if spacing==4
D=input('Distance between cond in mtrs=')
R=input('Radius_cond in mtrs=')
C=(2*pi*8.854*10^(-12))/log(D/R)
L=10^(-7)*(0.5+2*log(D/R))
else
end
if spacing==5
D12=input('Distance between cond 1&2 in mtrs=')
D23=input('Distance between cond 2&3 in mtrs=')
D31=input('Distance between cond 3&1 in mtrs=')
R=input('Radious_cond in mtrs=')
D=(D12*D23*D31)^(1/3)
L=10^(-7)*(0.5+2*log(D/R))
C=(2*pi*8.854*10^(-12))/log(D/R)
else
end
end
end
%%Coding belongs to
howtousematlab.blogspot.com%%
