Function: Series addition implementation

5 次查看（过去 30 天）

Kamilu Sanusi 2023-1-29

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1902780-function-series-addition-implementation

评论： Walter Roberson 2023-2-2

Hello

I am trying to solve an equation of which i need to be using the new values of V and delta as an update in equations (1).The closed equation (1) when expanded will be in the form of equation (2) for i = 2 and j is between 1 -5.

% P(i) = sum(j=1->n) |Vi||Vj|(Gij * cos(delta_i - delta_j) + Bij * sin(delta_i - delta_j) EQUATION (1) % The formula for calculating the P

Implementation of P(2) for example:

P(2) = P(2) + V(2)*V(1)*(G(2,1)*cos(delta(2)-delta(1)) + B(2,1)*sin(delta(2)-delta(1))) + V(2)*V(2)*(G(2,2)*cos(delta(2)-delta(2)) + B(2,2)*sin(delta(2)-delta(2))) + V(2)*V(3)*(G(2,3)*cos(delta(2)-delta(3)) + B(2,3)*sin(delta(2)-delta(3))) + V(2)*V(4)*(G(2,4)*cos(delta(2)-delta(4)) + B(2,4)*sin(delta(2)-delta(4))) + V(2)*V(5)*(G(2,5)*cos(delta(2)-delta(5)) + B(2,5)*sin(delta(2)-delta(5))) EQUATION (2)

Please is the below program good enough to represent the expansion of P(2) in equation (2) as an example ?

% Program
P = zeros(nbus,1);
Q =  zeros(nbus,1);
V =  zeros(nbus,1);
% B and G are constants
% Computing P
% nbus = 5
for i = 1:nbus
    for j = 1:nbus
        if type(i) == 2     % Computing Pi & Qi for Droop bus
            P(i) = V(i)*V(j)*(G(i,j)*cos(delta(i)-delta(j)) + ...
                B(i,j)*sin(delta(i)-delta(j)))+ PO(i)-PL(i);
            Q(i) = V(i)*V(j)*(G(i,j)*sin(delta(i)-delta(j)) - ...
                B(i,j)*cos(delta(i)-delta(j)))+ QO(i)-QL(i);
        end
    end
end

5 个评论
显示 3更早的评论隐藏 3更早的评论

Dyuman Joshi 2023-1-31

编辑：Dyuman Joshi 2023-1-31

Okay. But still have not answered my other queries.

The equation in the link do not contain PO, PL, QO and QL, where as your code does.

Walter Roberson 2023-2-2

在 MATLAB Online 中打开

for i = 1:nbus
    for j = 1:nbus
        if type(i) == 2     % Computing Pi & Qi for Droop bus

That is inefficient. type(i) does not change according to changes in j, so you should be testing type(i) outside the for j loop, only executing the for j loop if type(i) == 2

            P(i) = V(i)*V(j)*(G(i,j)*cos(delta(i)-delta(j)) + ...
                B(i,j)*sin(delta(i)-delta(j)))+ PO(i)-PL(i);
            Q(i) = V(i)*V(j)*(G(i,j)*sin(delta(i)-delta(j)) - ...
                B(i,j)*cos(delta(i)-delta(j)))+ QO(i)-QL(i);

P(i) does not depend upon P(i) or Q(i) so at each different j you completely overwrite P(i) and Q(i) and the final result will be the same as if you had only done the final j=nbus .

请先登录，再进行评论。

请先登录，再回答此问题。