Can someone help me create my loops?

[EDIT: 20110723 20:33 CDT - reformat - WDR]

I need help in creating these loops properly. Also, how do you update your M-File after making changes without going to edit-run-config's and then copy & pasting?

%----------------------------------------------------------------

clear , clc ;

E = 1.05;          % Per-Unit Voltage
X = 0.75;          % Per-Unit Reactance
PF = input(' input Power Factor ');    
% PF = 1.0, 0.95 Leading or 0.95 Lagging
% Leading indicates negative phase angle

% Lagging PF Maximum Active Power
Pmaxp = ( PF / ( 1 + sin ( acos ( PF ) ) ) * E ^ 2 / ( 2 * X ))

% Leading PF Maximum Active Power
Pmaxp = ( PF / ( 1 - sin ( acos ( PF ) ) ) * E ^ 2 / ( 2 * X ))

n = 1;
for v = 0 : 0.05 : 2; 

v;    

Q(n) = - v ^ 2 / X + E * v * PF / X;      % Per-Unit Reactive Power

n = n + 1;

end 

n=1;

for P = 0 : 0.05 : 2; 

P;    

V(n) = (E^2/2-Q*X+(E^4/4-X^2*P^2-X*E^2*Q)^0.5)^0.5;
%Per-Unit Voltage

n = n + 1;

end

figure ( 1 );
set (gca, 'FontSize', 12)
plot (V , P), grid on
xlabel ('Real Power [Per-Unit]','FontSize',14);
ylabel ('Voltage [Per-Unit]','FontSize',14);

[Jan]

Please format your code properly. See the "{} code" button and read the "Markup" link on this page.

If you want us to make your loops properly, please describe, why they are not proper in the current version.

Answer 1

[Fangjun Jiang]

Not sure what do you mean exactly? Do you want to debug your code to make it run? Or do you want to vectorize to eliminate the for-loop?

Tried your code, looks like you need to make changes in two lines.

V(n) = (E^2/2-Q(n)*X+(E^4/4-X^2*P^2-X*E^2*Q(n))^0.5)^0.5;%%change to Q(n)

plot (V , Q), grid on %%probably a typo

[Daniel]

Thanks. It's actually supposed to be a PV curve. I recognize now I can't plot with just the "for" P part versus the V(n) and I'm going to try to add an equation for that.