3 The 6bus power system in literature known as Ward and Hall

3) The 6-bus power system, in literature known as Ward and Halle, is given with one-line diagram in Fig. 1 and parameters in Table. 1. Using MATLAB function bldybus.m calulate Ybus matrix.

Solution

% Program to form Admittance Bus Formation without Transformer Tap setting

num = 6; % IEEE-6 bus systems..
linedata = linedata(num); % Calling \"linedata.m\" for Line Data...
fb = linedata(:,1);
tb = linedata(:,2);
r = linedata(:,3);
x = linedata(:,4);
b = linedata(:,5);
a = linedata(:,6);
z = r + 1i*x;
y = 1./z;
b = 1i*b;

nbus = max(max(fb),max(tb));
nbranch = length(fb);
Y = zeros(nbus,nbus);

% Formation of the Off Diagonal Elements %
for k=1:nbranch
Y(fb(k),tb(k)) = Y(fb(k),tb(k))-y(k)/a(k);
Y(tb(k),fb(k)) = Y(fb(k),tb(k));
end

% Formation of Diagonal Elements %
for m =1:nbus
for n =1:nbranch
if fb(n) == m
Y(m,m) = Y(m,m) + y(n)/(a(n)^2) + b(n);
elseif tb(n) == m
Y(m,m) = Y(m,m) + y(n) + b(n);
end
end
end
Y; % Bus Admittance Matrix%

Line data

% | From | To | R | X | B/2 | X\'mer | %
% | Bus | Bus | pu | pu | pu | TAP (a) |%
linedat = [1 4 0.080 0.370 0.00028 0
2 3 0.723 1.050 0 0
2 5 0.282 0.640 0 0
3 4 0.0 0.266 0 0
5 6 0.0 0.428 0 0
6 4 0.97 0.0407 0.0003 0
6 1 0.123 0.158 0.00028 0];