I have write a decoupled power flow program. The code has no problem. However, my results about the reactive power generation are negative. This should be positive. It seems that unreasonable. Can anyone who are experts in power engineering help me,thank you very much? * m = find(Bus_type ~= 1); * n = find(Bus_type == 3); * p = find(Bus_type == 1); * %Build the B' and B'' matrix * B1 = inv(imag(Y(m,m))); * B2 = inv(imag(Y(n,n))); * %Find the real and reactive power mismatch * theta_est = zeros(length(ID_bus),1); %Initial Estimate of Angle * iteration = 200; %Number of iteration * iter = 1; * %dP = zeros(length(ID_bus),1); * %dQ = zeros(length(ID_bus),1); * %Start iteration * for iter = 1:iteration * P = zeros(length(ID_bus),1); * Q = zeros(length(ID_bus),1); * for i=1:length(ID_bus) * for j=1:length(ID_bus) * P(i) = P(i) + Vhold(i)*Vhold(j)*abs(Y(i,j))*cos(angle(Y(i,j))-theta_est(i)+theta_est(j)); * Q(i) = Q(i) - Vhold(i)*Vhold(j)*abs(Y(i,j))*sin(angle(Y(i,j))-theta_est(i)+theta_est(j)); * end * end * dP = P_sch(m) - P(m); * dQ = Q_sch(n) - Q(n); * %Find the mismatch Angle * dtheta = -B1*dP./Vhold(m); * %Update the angle * theta_est(m) = theta_est(m) + dtheta; * %Find the mismatch Voltage * dV = -B2*dQ./Vhold(n); * %Update the Voltage * Vhold(n) = Vhold(n) + dV; * %Convergence tolerance * Tolerance = max(max(abs(dP)),max(abs(dQ))); * end

What's wrong with my decoupled power flow program

Nguyen

2014 12 11

0 个回答

10 次查看（30 天）

0 个投票

I have write a decoupled power flow program. The code has no problem. However, my results about the reactive power generation are negative. This should be positive. It seems that unreasonable. Can anyone who are experts in power engineering help me,thank you very much?

m = find(Bus_type ~= 1);
n = find(Bus_type == 3);
p = find(Bus_type == 1);
%Build the B' and B'' matrix
B1 = inv(imag(Y(m,m)));
B2 = inv(imag(Y(n,n)));
%Find the real and reactive power mismatch
theta_est = zeros(length(ID_bus),1); %Initial Estimate of Angle
iteration = 200; %Number of iteration
iter = 1;
%dP = zeros(length(ID_bus),1);
%dQ = zeros(length(ID_bus),1);
%Start iteration
for iter = 1:iteration
P = zeros(length(ID_bus),1);
Q = zeros(length(ID_bus),1);
for i=1:length(ID_bus)
for j=1:length(ID_bus)
P(i) = P(i) + Vhold(i)*Vhold(j)*abs(Y(i,j))*cos(angle(Y(i,j))-theta_est(i)+theta_est(j));
Q(i) = Q(i) - Vhold(i)*Vhold(j)*abs(Y(i,j))*sin(angle(Y(i,j))-theta_est(i)+theta_est(j));
end
end
dP = P_sch(m) - P(m);
dQ = Q_sch(n) - Q(n);
%Find the mismatch Angle
dtheta = -B1*dP./Vhold(m);
%Update the angle
theta_est(m) = theta_est(m) + dtheta;
%Find the mismatch Voltage
dV = -B2*dQ./Vhold(n);
%Update the Voltage
Vhold(n) = Vhold(n) + dV;
%Convergence tolerance
Tolerance = max(max(abs(dP)),max(abs(dQ)));
end