I need help in matlab codes please
kindly read the comments as well for better understanding of code
MATLAB CODE:
a=-0.5+0.866i; % operator 'a' in fault analysis
p=input('enter the faulted phase number:');
Vs=zeros(3,1); %array to store prefualt voltages
Vs(p,1)=input('enter the pre-fault voltage of faulted phase(in
pu):');
Vsy=zeros(3,1); %symmetrical component of phase(line to ground)
voltages
Iph=zeros(3,1); %array of phase currents
H=input('enter 1 if data is in sequence impedance else enter 0 for
self and mutual impedances:');
if(H==1)
Zo=input('enter zero sequence impedance (in pu):');
%enter zero sequence impedance value= 0.1i at command prompt for
given problem as it is reactance only
Z1=input('enter positive sequence impedance (in
pu):'); % positive sequence impedance value= 0.2i at command prompt
for given problem as it is reactance only
Z2=input('enter negative sequence impedance (in
pu):'); % negative sequence impedance value= 0.3i at command prompt
for given problem as it is reactance only
Zf=input('enter fault impedance (in pu):'); %fault
impedance value=0 at command prompt since no value is given in
problem
else
Zf=input('enter fault impedance (in pu):');
Zs=input('enter self impedance of transmission line(in
pu):'); %enter self impedance value in terms of i at command prompt
if it is reactance only
Zm=input('enter mutual impedance between transmission
line(in pu):'); %enter mutual impedance in terms of i at command
prompt if it is reactance only
Zo=Zs+(2*Zm); %zero sequence impedance
Z1=Zs-Zm; % positive sequence
impedance
Z2=Z1; % negative
sequence impedance
end
Iph(p,1)=(3*Vs(p,1))/(Zo+Z1+Z2+Zf);
fprintf('fault current is (%f)+(%fi)
\n',real(Iph(p,1)),imag(Iph(p,1)));
T=(1/3)*[1 1 1;1 a a*a;1 a*a a]; %T is inverse of symmetrical
component transformation matrix
Isy=T*Iph;
Vsy(1,1)=-Isy(1,1)*Zo;
Vsy(2,1)=Vs(p,1)-Isy(2,1)*Z1;
Vsy(3,1)=-Isy(3,1)*Z2;
Vph=inv(T)*Vsy;
fprintf('line to ground voltage of phase a is \n');
disp(Vph(1,1));
fprintf('line to ground voltage of phase b is \n');
disp(Vph(2,1));
fprintf('line to ground voltage of phase c is \n');
disp(Vph(3,1));
RESULT:
pic of code in editor:
Single line to ground fault analysis Example 9.4 Problem 1 A three-phase, il kV, 30 MVA alternato...
Bus A Bus B R1 T1 line 1 20% 80% line 2 T2 R2 110 kV 11 kV The fault is located at point F, which is 20% of the total line 2 length from Bus B Fault MVA 1524.20471 Three-phase fault level in MVA at bus A SPFL (kA) 8 MVA1 MVA2 X1 (96) X2 (96) R1 (2) R2 (Q) z' (Q) Zo (2) Rf (Q) Single phase to ground fault level (kA) at bus A Transformer 1 MVA...
Calculate the per-unit, subtransient fault currents for:
a) a bolted single line to ground short circuit from from
phase to a ground at bus 3. Also calculate the per-unit line to
ground voltages at faulted bus 3, and the line currents.
b) a bolted line to line fault from phase b to c at bus 3.
Also calculate the per-unit line to ground voltages at faulted bus
3.
c) a bolted double lime to ground from phase b to c...
The positive, negative and zero-sequence reactances of a 20-MVA, 13.2 kV synchronous generator are 0.3 pu, 0.2 pu, and 0.1 pu respectively. The generator is solidly grounded and is not loaded. If a double line-to-ground fault occurs at the generator terminals, calculate: (i) The fault current (ii) The line voltages (iii) Explain the steps that was carried out in the sequence voltage changes at all buses of the system. (Do include explanations and analysis of your solutions such as use...
Bus A Bus B R1 TI ine 1 20% 80% line 2 T2 R2 110 kV 11 kV The fault is located at point F, which is 20% of the total line 2 length from Bus B Fault MVA 1524.20471 Three-phase fault level in MVA at bus A SPFL (kA) 8 MVA1 MVA2 X1 (96 X2 (96) R1 (2) R2 (Q) z' (Q) Zo (2) Rf (Q) Single phase to ground fault level (kA) at bus A Transformer 1 MVA...
Problem 2 (10 pts) 132 kV TL 40 km 1 pu mid-point L-E fault 60 ΛΤΑ TL: Transmission line. L-E fault: Line-to-earth fault. Z. 0.07 pu 0.1 pu Generator 0.1 pu 0.1 pu 0.1 pu Transformers 2.5x Z] Transmission Line 0.7 Ω/km 0.7 Ω/km Suppose a single L-E fault happens at the mid-point of the transmission line. Determine the per unit phase voltage and current at point P (Choose Sbase-60 MVA and Vbase-132 kV). (4 pts) * The phase impedance...
Bus A Bus B R1 TI ine 1 20% 80% line 2 T2 R2 110 kV 11 kV The fault is located at point F, which is 20% of the total line 2 length from Bus B Fault MVA 1524.20471 Three-phase fault level in MVA at bus A SPFL (kA) 8 MVA1 MVA2 X1 (96 X2 (96) R1 (2) R2 (Q) z' (Q) Zo (2) Rf (Q) Single phase to ground fault level (kA) at bus A Transformer 1 MVA...
Please help me to answer those question and answer with PHASOR
MAGNITUDE and PHASE ANGLE
Part 1:
Taking the rated power of generator G1 as the base power, and
the transformer T1 low-voltage
side rated voltage as the base voltage, calculate the Thevanin’s
equivalent zero-sequence
impedance, positive sequence impedance and the negative sequence
impedance viewed from
Bus-2. Specify your answers in per-unit.
Part 2:
Assuming the pre-fault bus voltages are at 1.02 pu, calculate the
fault currents in each phase...
The single-line diagram of a three-phase power system is shown. Equipment ratings are given as follows: The inductor connected to generator 3 neutral has a reactance of \(0.05\) pu using generator 3 ratings as a base.1. Draw the zero-, positive-, and negative -sequence reactance diagrams using a \(1000 \mathrm{MVA}, 765 \mathrm{kV}\) base in the zone of line \(1-2\).2. Faults at bus 2 are of interest. Determine the Thevenin equivalent of each sequence network as viewed from the fault bus. Prefault voltage...
3. A 200 MVA, 20 kV, 60 Hz Y-connected solidly grounded three phase synchronous generator connected through a 200 MVA 20/138 KV Y-Y transformer to a 138 kV transmission line. The generator reactances to the machine's own base are X-1.10 Both of the transformers Y connections are solidly grounded and its positive, negative and zero sequence series resitances are all 0.10 pu. a. What is the voltage at the terminals of the generator during the sub transient period if a...
2. A single-line diagram of the power system considered is shown in Figure P2a, where negative- and zero-sequence reactances are also given. The neutrals of the generator and A-Y transformers are solidly grounded. The motor neutral is grounded through a reactance Xn = 0.05 per unit on the motor base. The per-unit zero-, positive and negative-sequence networks on a 100-MVA is shown in Figure P26, 13.8-kV base in the zone of the generator. a. Reduce the sequence networks to their...