Analysis Of Transmission Line Using MATLAB Software
1. 1
Koneru Lakshmaiah Education Foundation
(Deemed to be University)
DEPARTMENT OF ELECTRICAL
AND ELECTRONICS ENGINNERING
A Project Based Lab Report
On
Analysis of Transmission Line using MATLAB software
SUBMITTED BY:
NAME Regd. No.
B. Uma Sankar Rao 180060009
E. William Cary 180069011
UNDER THE GUIDANCE OF
Dr. K. P. Prasad Rao
KL UNIVERSITY
Green fields, Vaddeswaram – 522 502
Guntur Dt., AP, India.
2. 2
DEPARTMENT OF ELECTRICAL
AND ELETRONICS ENGINEERING
CERTIFICATE
This is to certify that the project based laboratory report entitled
that “Analysis of Transmission line using MATLAB software” submitted by Mr.
B. Uma Sankar Rao, Mr. E. William Cary bearing Regd. No. 180060009,
180069011 to the Department of ELECTRICAL AND ELECTRONICS
Engineering, KL University in partial fulfillment of the requirements for the
completion of a project based Laboratory in “Technical skills IV
(MATLAB)”course in II B.Tech., II Semester, is a bonafide record of the work
carried out by him under my supervision during the academic year 2019 – 2020.
PROJECT SUPERVISOR HEAD OF THE DEPARTMENT
3. 3
ACKNOWLEDGEMENTS
It is great pleasure for me to express my gratitude to our honorable
President Sri. Koneru Satyanarayana, for giving the opportunity and platform
with facilities in accomplishing the project based laboratory report.
I express the sincere gratitude to our principal Prof Dr. K. SUBBA RAO for
his administration towards our academic growth.
I express sincere gratitude to HOD-EEE Dr.S.V.N.LALITHA for his
leadership and constant motivation provided in successful completion of our
academic semester. I record it as my privilege to deeply thank for providing us
the efficient faculty and facilities to make our ideas into reality.
I express my sincere thanks to our project supervisor DR.M.SAI KRISHNA
REDDY for his novel association of ideas, encouragement, appreciation and
intellectual zeal which motivated us to venture this project successfully.
Finally, it is pleased to acknowledge the indebtedness to all those who
devoted themselves directly or indirectly to make this project report success.
Name Redg. No.
B. Uma Sankar Rao 180060009
E. William Cary 180069011
4. 4
INDEX
S. No Content Page No.
1. Abstract 5
2. Aim 6
3. Apparatus 7
4. About syntax used in
programming
8 – 9
5. Procedure 10
6. Code 11 – 13
7. Output 14 – 16
8. Advantages and
disadvantages
17
9. Conclusion 18
10. References 19
5. 5
ABSTRACT
Power systems is one of the subject studying of power generation,
transmission, distribution, utilization. Electrical – power transmission is the bulk
transfer of electrical energy, from generating power plants to electrical substations and
customers, which is typically referred to as electric power distribution. Transmission
lines, when interconnected with each other, become transmission networks. The
combined transmission and distribution network is known as the “National Grid”. Most
transmission lines are high voltage three phase alternating current, although single
phase AC is sometimes used in railway electrification systems. There are two types of
transmission lines they are DC transmission line and AC transmission lines. Long back
ago we were used DC transmission, Now the present world using AC transmission lines.
In both DC and AC transmission line, AC transmission line calculations are very tough
and very important than DC transmission line. In analysis of transmission the
important one is to find out efficiency and regulation. It is some difficult to make
calculation with hand it takes long period of time. To reduce time, this efficiency and
regulation gone on programming using MATLAB software, user interface is very easier
to use.
Through this analysis of transmission line programming using MATLAB user can
obtain length, efficiency, regulation of short, medium, long transmission line.
6. 6
AIM
It is very difficult to calculate the Efficiency, Regulation, Losses, Length of a
transmission line theoretically, it takes so much to obtain the result. That’s why
programming make it simpler. There are several programming languages but especially
MATLAB software programming compared to other languages, then it is a weakly typed,
dynamic, interpreted programming language specialized for numerical computations
and data visualization. MATLAB makes it simpler. The main aim of this project is
Analysis of Transmission line using MATLAB software. By using this user can get the
efficiency, regulation, length of transmission line and ABCD parameters.
7. 7
APPARATUS
A computer system with MATLAB installation with good
processor and RAM.
SOFTWARE REQUIREMENTS:
Programming skills.
Formulas of transmission line
Switch syntax.
Editor window.
Command window.
8. 8
About syntax used in programming
input: For example, x = input(prompt) displays the text in prompt and waits for the
user to input a value and press the Return key. The user can enter expressions, like pi/4
or rand(3), and can use variables in the workspace.
If the user presses the Return key without entering anything, then input returns
an empty matrix.
If the user enters an invalid expression at the prompt, then MATLAB display the
relevant error message, and then redisplays the prompt.
disp: disp(x) displays the value of variable x without printing the variable name.
Another way to display a variable is to type its name, which display a leading “x = “
before the value. If a variable contains an empty array, disp returns without displaying
anything.
fprintf: fprintf ( fileID, formatspec, A1,…An) applies the formatspe to all elements of
array A1,…An in column order, and writes the data to a text file. Fprintf uses the
encoding scheme specified in the call to fopen.
complex: In MATLAB, i and j represent the basic imaginary unit. You can use them to
create complex numbers such as 2i+5 . You can also determine the real and imaginary
parts of complex numbers and compute other common values such as phase and angle.
imag: imag( MATLAB functions ) Y = imag( Z ) returns the imaginary part of the
elements of array Z.
abs: abs( z ) returns the absolute value (or complex modulus ) of z. Because symbolic
variables are assumed to be complex by default, abs return the complex modulus
(magnitude ) by default. If z is an array, abs acts element – wise on each element of z.
9. 9
conj: conj( x ) returns the complex conjugate of x. Because symbolic variables are
complex by default, unresolved calls, such as conj( x ), can appear in the output of norm,
mtimes, and other functions. For details, see use assumptions on symbolic variables.
sqrt: sqrt( MATLAB functions)B = sqrt( x ) returns the square root of each element of
the array x. For the elements of X that are negative or complex, sqrt ( x ) produces
complex results.
10. 10
Procedure
Procedure for this project is very simple. Installation must be there in computer
device, because it program based project.
1. Open MATLAB.
2. Type command in command window that is edit window.
3. Type the program according to the formula of transmission line and MATLAB
syntax in edit window.
4. MATLAB program evaluation is top to bottom and left to right.
5. Completion of whole program, Click on Run option in MATLAB window.
6. Enter values according to the program visible in command window.
7. Results will obtain.
11. 11
Code
clc;
clear all;
disp('********** ANALYSIS OF TRANSMISSION LINE **********')
disp(' ')
disp('1. Find length of transmission line ')
disp('2. Finding Efficiency and Regulation of a transmission line')
disp(' ')
Op = input('Enter your option:');
disp(' ')
switch Op
case 1;
Pr=input('Enter Power Receiving end: ');
Ef=input('Enter Efficiency of transmission line: ');
Vr=input('Enter Receiving end voltage: ');
a=input('Enter copper conductance: ');
Ps=Pr/Ef;
ll=Ps-Pr;
I=Pr/(Vr*1);
R=ll/(2*(I^2));
L=(R*a)/(1.725*10^6);
disp('Power sending end: ')
disp(Ps)
disp('Line losses: ')
disp(ll)
disp('The length of transmission line: ')
disp(L)
if L <=60
fprintf('This is a Short transmission line')
disp(' ')
else if L>60 && L<160
fprintf('This is Medium transmission line')
disp(' ')
else
fprintf('This is Long transmission line')
disp(' ')
end
end
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case 2;
L=input('Length of transmission line in kmn ');
Vl=input('receiving end voltage in kvn ');
r=input('Per km resistance in ohmn ');
l=input('Per km inductance in mHn ');
S=input('Receiving power in MVAn ');
Fi=input('Lagging power factorn ');
S=S*(10^6);
Vl=Vl*(10^3);
l=l*(10^-3);
ind=L*(l);
R=r*(L);
Vr=Vl/sqrt(3);
Z=complex(R,2*pi*50*ind);
j=sqrt(-1);
if L <= 60
disp('------ THIS IS SHORT TRANSMISSION LINE ------')
disp(' ')
A=1;
B=Z;
C=0;
D=A;
elseif L > 60 && L <= 160
disp('------ THIS IS MEDIUM SHORT TRANSMISSION LINE ------')
disp(' ')
c=input('Per km capacitance in uFn ');
c=c*(10^-6);
Y=2*pi*50*c*L*j;
A=(Y/2)*Z+1;
B=Z*((Y/4)*Z+1);
C=Y;
D=A;
else
disp('------ THIS IS LONG TRANSMISSION LINE ------')
disp(' ')
c=input('Per km capacitance in uFn ');
c=c*(10^-6);
Y=2*pi*50*c*L*j;
K=sqrt(Y*Z);
M=sqrt(Y/Z);
A=cosh(K);
14. 14
Output
********** ANALYSIS OF TRANSMISSION LINE **********
1. Find length of transmission line
2. Finding Efficiency and Regulation of a transmission line
Enter your option:2
Length of transmission line in km
50
receiving end voltage in kv
33000
Per km resistance in ohm
0.2
Per km inductance in mH
0.3
Receiving power in MVA
1100000
Lagging power factor
0.8
------ THIS IS SHORT TRANSMISSION LINE ------
No load receiving end voltage
15. 15
1.9053e+07
No load sending end current
1.9245e+04
Sending end p.f.
0.8013
Voltage Regulation of the line
1.0939
Transmission Efficiency of the line
98.7531
********** ANALYSIS OF TRANSMISSION LINE **********
1. Find length of transmission line
2. Finding Efficiency and Regulation of a transmission line
Enter your option:1
Enter Power Receiving end: 200000
Enter Efficiency of transmission line: 0.9
Enter Receiving end voltage: 3300
Enter copper conductance: 0.775
Power sending end:
17. 17
Advantages
1. Easy to calculate efficiency, regulation, losses, length of transmission line
using programing without theoretically.
2. Time saves.
3. Easy to use
4. User friendly
5. Well developed user interface.
Dis advantages
1. No everyone effort portable computer and desktop computers to calculate
efficiency, regulation, losses, length of transmission line. For this
programming, hardware must be developed
18. 18
CONCLUSION
By carrying out this project, it’s very easy to make calculation of
transmission line that is efficiency, regulation, losses and length. By
entering the power receiving end, efficiency of transmission line,
receiving end voltage, and copper conductance the resultant output user
can get line losses, length of transmission line and which type of
transmission line it is. By entering length of transmission line, receiving
end voltage, resistance per km, inductance per km, receiving power,
lagging power factor and user get no load receiving end voltage, no load
sending end current, sending end power factor, voltage regulation of the
line, transmission efficiency of the line.