Putting a capacitor in the thread of the load distribution (backward and forward method)

I have a MATLAB code of load distribution using backward and forward method. I want to have a table consisting of capacitor values (for example, 100 kilovar, 125 kilovar, etc.) and calculate the reactive power of the feeder. I put the capacitor in each of the busses to check the loss where it is less. In the output, a table should be given that each bus can have the least losses with the amount of capacitor capacity. Can anyone help me in this regard?

I want to do this with For loops.

Code:

LD = load('linedata.m'); %line data
BD = load('busdata.m'); %bus data

%for transform data to pu, first define basic power and basic voltage
Sbase = 100; %MVA [Power]
Vbase = 11; %KV [Voltage]
Zbase = (Vbase^2)/Sbase; %[Impedance]

%convert to pu data
LD(:,4:5) = LD(:,4:5)/Zbase; 
BD(:,2:3) = BD(:,2:3)/(1000*Sbase);

rowLD = 32;
rowBD = 33;

Sload = complex(BD(:,2),BD(:,3)); %power of each load

V = ones(rowBD,1); %initial voltage value.

Z = complex(LD(:,4),LD(:,5));

Iline = zeros(rowLD,1);

Iter = 2000;

%% The algorithm

%Backward
for i=1:Iter
    Iload = conj(Sload/V);
    
    for j = size(LD,1):-1:1 %start from the end of the feeder
        r = [];
        c = [];
        [r c] = find(LD(:,2:3)==LD(j,3));
        
        if size(r,1)==1
            Iline(LD(j,1)) = Iload(LD(j,3));
        else
            Iline(LD(j,1)) = Iload(LD(j,3))+sum(Iline(LD(r,1)))-Iline(LD(j,1));
        end
    end

%Forward
for h = 1:rowLD
    V(LD(h,3)) = V(LD(h,2))-Iline(LD(h,1))*Z(h);
    end

end

Voltage = abs(V);
Vangle = angle(V);

%% Losses
P = real(Z.*(Iline.^2));
Q = imag(Z.*(Iline.^2));

%% Plot
plot(Voltage)

Bus data:

%line no.   P (KVA)     Q (KVA)
1           0           0
2           100         60
3           90          40
4           120         80
5           60          30
6           60          20
7           200         100
8           200         100
9           60          20
10          60          20
11          45          30
12          60          35
13          60          35
14          120         80
15          60          10
16          60          20
17          60          20
18          90          40
19          90          40
20          90          40
21          90          40
22          90          40
23          90          50
24          420         200
25          420         200
26          60          25
27          60          25
28          60          20
29          120         70
30          200         600
31          150         70
32          210         100
33          60          40

Line data:

%Line no.   From        To          R               X
1           1           2           0.0922          0.0470
2           2           3           0.4930          0.2511
3           3           4           0.3660          0.1864
4           4           5           0.3811          0.1941
4           5           6           0.8190          0.7070
6           6           7           0.1872          0.6188
7           7           8           0.7114          0.2351
8           8           9           1.0300          0.7400
9           9           10          1.0440          0.7400
10          10          11          0.1966          0.0650
11          11          12          0.3744          0.1238
12          12          13          1.4680          1.1550
13          13          14          0.5416          0.7129
14          14          15          0.5910          0.5260
15          15          16          0.7463          0.5450
16          16          17          1.2890          1.7210
17          17          18          0.7320          0.5740
18          2           19          0.1640          0.1565
19          19          20          1.5042          1.3554
20          20          21          0.4095          0.4784
21          21          22          0.7089          0.9373
22          3           23          0.4512          0.3083
23          23          24          0.8980          0.7097
24          24          25          0.8960          0.7011
25          6           26          0.2030          0.1034
26          26          27          0.2842          0.1447
27          27          28          1.0590          0.9337
28          28          29          0.8042          0.7006
29          29          30          0.5075          0.2585
30          30          31          0.9744          0.9630
31          31          32          0.3105          0.3619
32          32          33          0.3410          0.5302

Answer 1

[VBBV]

You can obtain it by multiplying the Iline and V and display them in table

LD = [%Line no.   From        To          R               X
1           1           2           0.0922          0.0470
2           2           3           0.4930          0.2511
3           3           4           0.3660          0.1864
4           4           5           0.3811          0.1941
4           5           6           0.8190          0.7070
6           6           7           0.1872          0.6188
7           7           8           0.7114          0.2351
8           8           9           1.0300          0.7400
9           9           10          1.0440          0.7400
10          10          11          0.1966          0.0650
11          11          12          0.3744          0.1238
12          12          13          1.4680          1.1550
13          13          14          0.5416          0.7129
14          14          15          0.5910          0.5260
15          15          16          0.7463          0.5450
16          16          17          1.2890          1.7210
17          17          18          0.7320          0.5740
18          2           19          0.1640          0.1565
19          19          20          1.5042          1.3554
20          20          21          0.4095          0.4784
21          21          22          0.7089          0.9373
22          3           23          0.4512          0.3083
23          23          24          0.8980          0.7097
24          24          25          0.8960          0.7011
25          6           26          0.2030          0.1034
26          26          27          0.2842          0.1447
27          27          28          1.0590          0.9337
28          28          29          0.8042          0.7006
29          29          30          0.5075          0.2585
30          30          31          0.9744          0.9630
31          31          32          0.3105          0.3619
32          32          33          0.3410          0.5302]; %load('linedata.m'); %line data
BD = [%line no.   P (KVA)     Q (KVA)
1           0           0
2           100         60
3           90          40
4           120         80
5           60          30
6           60          20
7           200         100
8           200         100
9           60          20
10          60          20
11          45          30
12          60          35
13          60          35
14          120         80
15          60          10
16          60          20
17          60          20
18          90          40
19          90          40
20          90          40
21          90          40
22          90          40
23          90          50
24          420         200
25          420         200
26          60          25
27          60          25
28          60          20
29          120         70
30          200         600
31          150         70
32          210         100
33          60          40
]; %load('busdata.m'); %bus data

%for transform data to pu, first define basic power and basic voltage
Sbase = 100; %MVA [Power]
Vbase = 11; %KV [Voltage]
Zbase = (Vbase^2)/Sbase; %[Impedance]

%convert to pu data
LD(:,4:5) = LD(:,4:5)/Zbase

LD = 32×5

1.0000 1.0000 2.0000 0.0762 0.0388 2.0000 2.0000 3.0000 0.4074 0.2075 3.0000 3.0000 4.0000 0.3025 0.1540 4.0000 4.0000 5.0000 0.3150 0.1604 4.0000 5.0000 6.0000 0.6769 0.5843 6.0000 6.0000 7.0000 0.1547 0.5114 7.0000 7.0000 8.0000 0.5879 0.1943 8.0000 8.0000 9.0000 0.8512 0.6116 9.0000 9.0000 10.0000 0.8628 0.6116 10.0000 10.0000 11.0000 0.1625 0.0537

BD(:,2:3) = BD(:,2:3)/(1000*Sbase);

rowLD = 32;
rowBD = 33;

Sload = complex(BD(:,2),BD(:,3)); %power of each load

V = ones(rowBD,1); %initial voltage value.

Z = complex(LD(:,4),LD(:,5));

Iline = zeros(rowLD,1);

Iter = 2000;

%% The algorithm

%Backward
for i=1:Iter
    Iload = conj(Sload/V);
    
    for j = size(LD,1):-1:1 %start from the end of the feeder
        r = [];
        c = [];
        [r c] = find(LD(:,2:3)==LD(j,3));
        
        if size(r,1)==1
            Iline(LD(j,1)) = Iload(LD(j,3));
            V(LD(j,3)) = V(LD(j,2))-Iline(LD(j,1))*Z(j);
            R_pow(j) =   V(LD(j,3)).*Iline(LD(j,1));  % reactive power
        else
            Iline(LD(j,1)) = Iload(LD(j,3))+sum(Iline(LD(r,1)))-Iline(LD(j,1));
            V(LD(j,3)) = V(LD(j,2))-Iline(LD(j,1))*Z(j);
            R_pow(j) =   V(LD(j,3)).*Iline(LD(j,1));  % reactive power
        end
    end
%Forward  
end
Voltage = abs(V);
Vangle = angle(V);

%% Losses
P = real(Z.*(Iline.^2));
Q = imag(Z.*(Iline.^2));

T = table(abs(R_pow).',P,Q,'VariableNames',{'Reactive Power Capacity', 'Loss-Active','Loss-Reactive'})

T = 32×3 table
    Reactive Power Capacity    Loss-Active    Loss-Reactive
    _______________________    ___________    _____________

            0.043531           0.00013123      -9.7155e-05 
            0.037805           0.00053641      -0.00042162 
            0.026592           0.00018411      -0.00017698 
            0.024958           0.00017154      -0.00016599 
            0.023751                    0                0 
            0.011108            6.993e-05       2.8834e-05 
           0.0089637           4.9071e-05      -3.0574e-05 
           0.0068336           5.6198e-05      -1.3637e-05 
           0.0062074           4.7192e-05      -1.2789e-05 
            0.005628           5.4303e-06      -3.6064e-06 
           0.0051295           8.7704e-06      -5.5028e-06 
           0.0044635           3.7081e-05      -7.0659e-06 
           0.0038286           1.3327e-05       1.3234e-06 
           0.0025563           5.2777e-06       4.4316e-07 
           0.0020147           3.8386e-06      -3.7431e-07 
           0.0014445           4.5736e-06       7.7065e-07 

%% Plot
plot(Voltage)

[SNM Nima]

Thanks, but I didn't want a table, I wanted to compare the shape of the voltage improved by the capacitor with the shape of the previous voltage profile. Also, the capacity of the capacitor used and in which bus it is placed.

[VBBV]

"I want to have a table consisting of capacitor values (for example, 100 kilovar, 125 kilovar, etc.) and calculate the reactive power of the feeder. I put the capacitor in each of the busses to check the loss where it is less. In the output, a table should be given that each bus can have the least losses with the amount of capacitor capacity"

From your question and the description, it seems you wanted a table instead of graphs. If you need additional help on required graphs, please post a new question.

[SNM Nima]

Sorry, I explained badly. I will post a new one.