Use makeYbus function or use below code
% Program to for Admittance And Impedance Bus Formation....
function Y = ybusppg(num) % Returns Y
linedata = linedatas(num); % Calling Linedatas...
fb = linedata(:,1); % From bus number...
tb = linedata(:,2); % To bus number...
r = linedata(:,3); % Resistance, R...
x = linedata(:,4); % Reactance, X...
b = linedata(:,5); % Ground Admittance, B/2...
a = linedata(:,6); % Tap setting value..
z = r + i*x; % z matrix...
y = 1./z; % To get inverse of each element...
b = i*b; % Make B imaginary...
nb = max(max(fb),max(tb)); % No. of buses...
nl = length(fb); % No. of branches...
Y = zeros(nb,nb); % Initialise YBus...
% Formation of the Off Diagonal Elements...
for k = 1:nl
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:nb
for n = 1:nl
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
