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8/3/2019 Power System Faults _fault in 3phase System_project-1
1/15
Presented by: INDRAJEET PRASAD
SHIVANANDA PUKHREM
JOAN JIMIENEZ ANGELES
2011-12
WROCLAW UNIVERSITY OF TECHNOLOGYWROCLAW UNIVERSITY OF TECHNOLOGYWROCLAW UNIVERSITY OF TECHNOLOGYWROCLAW UNIVERSITY OF TECHNOLOGYFACULTY OF ELECTRICAL ENGINEERING
[ POWER SYSTEM FAULTPOWER SYSTEM FAULTPOWER SYSTEM FAULTPOWER SYSTEM FAULT
PROJECT NOPROJECT NOPROJECT NOPROJECT NO----1111 ]
Prof. Dr. Hab. In Jan Iykowski
8/3/2019 Power System Faults _fault in 3phase System_project-1
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2 Presented by: INDRAJEET PRASAD, SHIVANANDA PUKHREM, JOAN JIMIENEZ ANGELE
PROJECT NO-1POWER SYSTEM FAULT
INDEX:
2. Introduction 3
3. Variables used in the line code program. 4
4. Program code 5
5. Graphics results 10
5.1. Three phase voltage.. 105.2. Phase current and their magnitude. 11
5.3. Phase voltage and their magnitude 13
6. Consequences of the fault 14
7. Conclusion 15
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3 Presented by: INDRAJEET PRASAD, SHIVANANDA PUKHREM, JOAN JIMIENEZ ANGELE
PROJECT NO-1POWER SYSTEM FAULT
2. INTRODUCTION:
With this report we will try to familiarize with some code lines of Matlab. Thus in
the next pages will see how to get from a simulation of and electrical system
composed by one transmission line with 2 transformers for measuring (CT and VT)
We will see also how to work with some commands from Matlab that will be
useful to obtain some graphics which will help to get some information about
where and when has been the fault in the system.
There are two buses called (S)ending and (R)eciving. That has to be considered to
name the different variables.
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4 Presented by: INDRAJEET PRASAD, SHIVANANDA PUKHREM, JOAN JIMIENEZ ANGELE
PROJECT NO-1POWER SYSTEM FAULT
3. VARIABLES USED IN LINE CODE PROGRAM:
3.1 Information about the nomenclature of the simulation code.
Time interval: from tSTART=0 to tEND=12 ms
Fundamental frequency: f1=50 Hz
Sampling frequency: fs=1000 Hz.
n: 20. Number of number of samples in a single fundamental frequency period.
theta_i: 1500; CT ratio
theta_v: 3636.36; VT ratio
Current and voltages parameters:
iS_af: Side S phase 'a' current after filtration.
iS_bf: Side S phase 'b' current after filtration.
iS_cf: Side S phase 'c' current after filtration.
vS_af: Side S - phase 'a' voltage after filtration.
vS_bf: Side S - phase 'b' voltage after filtration.
vS_cf: Side S - phase 'c' voltage after filtration.
Notation used in the above specification of current and voltage signals: i-current;
v-voltage; S-sending end;
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5 Presented by: INDRAJEET PRASAD, SHIVANANDA PUKHREM, JOAN JIMIENEZ ANGELE
PROJECT NO-1POWER SYSTEM FAULT
4. PROGRAM CODE:
% cd d:\Student\PSFs_Pr1
% Pr1
clearall;
theta_i=1500; % CT ratio
theta_v=3636.36; % VT ratio
n=20; % number of samples in a single fundamental frequency period
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
Standard full-cycle FOURIER FILTRATION:
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
dT=2*pi/n;
fork=1:n,
alfa=dT/2+(k-1)*dT;
FF(k)=cos(alfa)+sqrt(-1)*sin(alfa);end;
FF=-2*FF/n;
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
READING AND TRANSPOSING *.PL4 FILES.
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
x=readpl452;
size(x),
y=x';
size(y),
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
CURRENT Signals after filtration (full-cycle FOURIER FILTRATION):
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
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6 Presented by: INDRAJEET PRASAD, SHIVANANDA PUKHREM, JOAN JIMIENEZ ANGELE
PROJECT NO-1POWER SYSTEM FAULT
iS_af(1,:)=theta_i*filter(FF,1,y(2
iS_bf(1,:)=theta_i*filter(FF,1,y(3,:));
iS_cf(1,:)=theta_i*filter(FF,1,y(4,:));
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
VOLTGAE Signals after filtration (full-cycle FOURIER FILTRATION):
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
vS_af(1,:)=theta_i*filter(FF,1,y(5,:));
vS_bf(1,:)=theta_i*filter(FF,1,y(6,:));
vS_cf(1,:)=theta_i*filter(FF,1,y(7,:));
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
PLOT FOR A SINGLE PHASES MAGNITUDE CURRENT:
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
figure(2);
plot(y(1,:), theta_i*y(2,:), 'r-');
holdon;
gridon;
plot(y(1,:), abs(iS_af(1,:)), 'r-', y(1,:), abs(iS_af(1,:)), 'ro');
title('Phase current and its magnitude');
xlabel('Time [s]'); ylabel('Current and Magnitude [A B C]');
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
PLOT FOR B SINGLE PHASES MAGNITUDE CURRENT:
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
figure(2);
plot(y(1,:), theta_i*y(3,:), 'g-');
holdon;
gridon;
plot(y(1,:), abs(iS_bf(1,:)), 'g-', y(1,:), abs(iS_bf(1,:)), 'gx');
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7 Presented by: INDRAJEET PRASAD, SHIVANANDA PUKHREM, JOAN JIMIENEZ ANGELE
PROJECT NO-1POWER SYSTEM FAULT
title('Phase current and its magnitude');
xlabel('Time [s]'); ylabel('Current and Magnitude [A B C]');
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
PLOT FOR C SINGLE PHASES MAGNITUDE CURRENT:
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
figure(2);
plot(y(1,:), theta_i*y(4,:), 'b-');
holdon;gridon;
plot(y(1,:), abs(iS_cf(1,:)), 'b-', y(1,:), abs(iS_cf(1,:)), 'bx');
title('Phase current and its magnitude');
xlabel('Time [s]'); ylabel('Current and Magnitude [A B C]');
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%PLOT FOR ALL THE VOLTAGES PHASES:
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
v_a=theta_v*y(5,:); % Phase 'a' voltage.
v_b=theta_v*y(6,:); % Phase 'b' voltage.
v_c=theta_v*y(7,:); % Phase 'c' voltage.
figure(1);
plot(y(1,:), v_a, 'r-', y(1,:), theta_v*y(6,:), 'g-', y(1,:), theta_v*y(7,:), 'b-');
plot(y(1,:), v_a, 'r-', y(1,:), v_b, 'g-', y(1,:), v_c, 'b-');
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8 Presented by: INDRAJEET PRASAD, SHIVANANDA PUKHREM, JOAN JIMIENEZ ANGELE
PROJECT NO-1POWER SYSTEM FAULT
grid;
title('Three-phase voltages');xlabel('Time [s]'); ylabel('Voltage [V]'); Legend('v_a','v_b','v_c');
% axis([0, 0.02, -500, 500]);
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
PLOT THE A SINGLE PHASE MAGNITUDE VOLTAGE:
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
figure(3);
plot(y(1,:), theta_i*y(5,:), 'r-');
holdon;
gridon;
plot(y(1,:), abs(vS_af(1,:)), 'rx', y(1,:), abs(vS_af(1,:)), 'rx');
title('Phases Voltage and Magnitude ');
xlabel('Time [s]'); ylabel('Voltage and Magnitude [A B C]');
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
PLOT THE B SINGLE PHASE MAGNITUDE VOLTAGE:
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
figure(3);
plot(y(1,:), theta_i*y(6,:), 'g-');
holdon;
gridon;
plot(y(1,:), abs(vS_bf(1,:)), 'go', y(1,:), abs(vS_bf(1,:)), 'go');
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9 Presented by: INDRAJEET PRASAD, SHIVANANDA PUKHREM, JOAN JIMIENEZ ANGELE
PROJECT NO-1POWER SYSTEM FAULT
title('Phases Voltage and Magnitude ');
xlabel('Time [s]'); ylabel('Voltage and Magnitude [A B C]');
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
PLOT THE C SINGLE PHASE MAGNITUDE VOLTAGE:
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
figure(3);
plot(y(1,:), theta_i*y(7,:), 'b-');
holdon;gridon;
plot(y(1,:), abs(vS_cf(1,:)), 'bo', y(1,:), abs(vS_cf(1,:)), 'bo');
title('Phases Voltage and Magnitude ');
xlabel('Time [s]'); ylabel('Voltage and Magnitude [A B C]');
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
END%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
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10 Presented by: INDRAJEET PRASAD, SHIVANANDA PUKHREM, JOAN JIMIENEZ ANGELE
PROJECT NO-1POWER SYSTEM FAULT
5. GRAPHICS RESULTS:
According to the kind of the time interval we can distinguished two main parts in
the graphics:
PRE-FAULT INTERVAL: From t-0 to t-6ms. There isn't any disturbance in the
amplitude of the voltages of the phases.
FAULT INTERVAL: From t-6ms to t-12ms. Here disturbance is occurred due tothe fault in the system.
The different graphics obtained from the program are showed down:
Fig 1: three phase voltage.
Fig 2: phase current and magnitude.Fig 3: phase voltage and magnitude.
Now we can star talk about the different results that are showed in the different
graphics.
5.1 Three phase voltage.
In this figure; we can see the three phase voltage. And as because of the fault theamplitude of the phase A and B decreases and phase C increases its original
amplitude.
Since due to fault in the system one of the phase is carrying more load so that the
reason its increasing its amplitude and the other two phases decreases its original
amplitude after fault.
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11 Presented by: INDRAJEET PRASAD, SHIVANANDA PUKHREM, JOAN JIMIENEZ ANGELE
PROJECT NO-1POWER SYSTEM FAULT
FIG:1 THREE PHASE VOLTAGE
5.2 Phase currents and their magnitude.
In this figure it represents the phase current and its magnitude of the system.
We know that,
P=V*I
As we saw before in figure 1, due to the fault in the system the voltage increased,
so if the power has to be maintain constant, the only parameter that has to
change is the current, because of that the current has suffered and increases of its
value and magnitude.
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12 Presented by: INDRAJEET PRASAD, SHIVANANDA PUKHREM, JOAN JIMIENEZ ANGELE
PROJECT NO-1POWER SYSTEM FAULT
FIG.2 : PHASE CURRENT AND ITS MAGNITUDE
5.3 Phases Voltage and their magnitude:
In figure 3, it depicts the magnitude of the phases A,B and C. As we can see in
figure due to the fault in the system, phases A and B magnitude reduces while themagnitude of phase C increases
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13 Presented by: INDRAJEET PRASAD, SHIVANANDA PUKHREM, JOAN JIMIENEZ ANGELE
PROJECT NO-1POWER SYSTEM FAULT
FIG.3 : THREE PHASE VOLATAGE AND MAGNITUDE
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14 Presented by: INDRAJEET PRASAD, SHIVANANDA PUKHREM, JOAN JIMIENEZ ANGELE
PROJECT NO-1POWER SYSTEM FAULT
6.CONSEQUENCES OF FAULTS:
Fire is a serious result of major un-cleared faults, may destroy the equipment of its
origin, but also may spread in the system causing total failure.
The short circuit (the most common type of fault) may have any of the following
consequences:
A great reduction of the line voltage over a major part of the power system,leading to the breakdown of the electrical supply to the consumer and may
produce wastage in production.
An electrical arc often accompanying a short circuit may damage the other
apparatus in the system.
Damage to the other apparatus in the system due to overheating and
mechanical forces.
Disturbances to the stability of the electrical system and this may even lead to a
complete blackout of a given power system.
Considerable reduction of voltage on healthy feeders connected to the system
having fault, which can cause abnormal currents drawn by motors or the motors
will be stopped (causing loss of industrial production) and then will have to be
restarted.
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15 Presented by: INDRAJEET PRASAD, SHIVANANDA PUKHREM, JOAN JIMIENEZ ANGELE
PROJECT NO-1POWER SYSTEM FAULT
7.CONCLUSION:
A fault in an electric power system is studied in this project through MATLAB
programming.
Any abnormal flow of electric current in an electric power system is considered as
a fault.In this particular project the fault is occurred between two phases A and B i.e, Red
and Green.
The fault can be between phase to phase, phase to ground or phase to phase to
ground. Through this project we have learn that due to any kind of fault in three
phase system there is a transient sudden surge increase of current in the power
system affecting the other healthy lines.
Many faults in overhead power lines are transient in nature.
At the occurrence of a fault power system protection operates to isolate area of
the fault.A transient fault will then clear and the power line can resume to service.