Y Bus Assembly (Direct Method)

Y_Bus_Assembly_Direct.m

function yBus = Y_Bus_Assembly_Direct()
    % Data from IEEE 5-bus Data
    % "http://shodhganga.inflibnet.ac.in/bitstream/10603/26549/14/14_appendix.pdf""
    lineData = csvread('Y_Bus_Data.csv', 1, 0);
    % Calculate the number of lines in the line data
    lines = length(lineData);
    % Calculate the number of buses in the line data
    buses = max(max(lineData(:,2)),max(lineData(:,3)));
    % Calculate the line admittance by taking element by element inverse
    lineAdmittance = lineData(:,4).^-1;
    % Store the shunt admittance in a separate matrix
    shuntAdmittance = lineData(:,5);
    % Initialize a Ybus matrix of dimension buses X buses with all zeros
    yBus = zeros(buses,buses);

    % k variable traverses the lineData matrix
    for k = 1:lines
        sendingBus = lineData(k,2);  
        receivingBus = lineData(k,3);
        % i and j traverse the Ybus matrix
        for i = 1:buses
           for j = 1:buses
               % For Diagonal Elements
               % i == j                         -> Checks that the element is a diagonal element
               % sendingBus==i||receivingBus==i -> Checks if the line is connected to either sending or receiving bus
               if(sendingBus==i||receivingBus==i)&&(i==j)
                    yBus(i,j) = yBus(i,j) + lineAdmittance(k) + shuntAdmittance(k);
               end
               % For Off Diagonal Elements
               % sendingBus==i&&receivingBus==j -> Checks if the line is connected between sensing and reciving bus
               if sendingBus==i&&receivingBus==j
                    yBus(i,j) = - lineAdmittance(k);
                    yBus(j,i) = - lineAdmittance(k);
               end
           end
       end
    end
    
end

Y_Bus_Data.csv