# Gauss Program on C++

Topics: For loop, Limit of a sequence, Limit superior and limit inferior Pages: 2 (369 words) Published: May 23, 2011
% Program for Gauss - Seidel Load Flow Analysis
% Assumption, Bus 1 is considered as Slack bus.

ybus = ybusppg(); % Calling program "ybusppg.m" to get Y-Bus. busdata = busdata6(); % Calling "busdata6.m" for bus data.
bus = busdata(:,1); % Bus number.
type = busdata(:,2); % Type of Bus 1-Slack, 2-PV, 3-PQ. V = busdata(:,3); % Initial Bus Voltages.
th = busdata(:,4); % Initial Bus Voltage Angles.
GenMW = busdata(:,5); % PGi, Real Power injected into the buses. GenMVAR = busdata(:,6); % QGi, Reactive Power injected into the buses. LoadMW = busdata(:,7); % PLi, Real Power Drawn from the buses. LoadMVAR = busdata(:,8); % QLi, Reactive Power Drawn from the buses. Qmin = busdata(:,9); % Minimum Reactive Power Limit

Qmax = busdata(:,10); % Maximum Reactive Power Limit
nbus = max(bus); % To get no. of buses
P = GenMW - LoadMW; % Pi = PGi - PLi, Real Power at the buses. Q = GenMVAR - LoadMVAR; % Qi = QGi - QLi, Reactive Power at the buses. Vprev = V;
toler = 1; % Tolerence.
iteration = 1; % iteration starting
while (toler > 0.00001) % Start of while loop
for i = 2:nbus
sumyv = 0;
for k = 1:nbus
if i ~= k
sumyv = sumyv + ybus(i,k)* V(k); % Vk * Yik end
end
if type(i) == 2 % Computing Qi for PV bus
Q(i) = -imag(conj(V(i))*(sumyv + ybus(i,i)*V(i))); if (Q(i) > Qmax(i)) || (Q(i) < Qmin(i)) % Checking for Qi Violation. if Q(i) < Qmin(i) % Whether violated the lower limit. Q(i) = Qmin(i);

else % No, violated the upper limit.
Q(i) = Qmax(i);
end
type(i) = 3; % If Violated, change PV bus to PQ bus. end
end
V(i) = (1/ybus(i,i))*((P(i)-j*Q(i))/conj(V(i)) - sumyv); % Compute...