How to find the peak values from simulink file(.slx) in matlab coding. I'm getting pks = 0×1 empty double column vector, locs = 0×1 empty double column vector errors.

The file .slx file is attatched below

[Mathieu NOE]

hello

I could not do the sim because I lack some toolboxes

can you save your simulation outputs to a mat file ?

[Mathieu NOE]

hello

as I said before , I cannot work from your sim because i don't have the library 'powerlib'

I could only help you if you could share the results of sim, saved in a mat file

tx

Answer 1

[Mathieu NOE]

hello

so the issue is to plot the max of your data (once taken the absoute value of it) . In this case findpeaks is overkill, a simple max is enough to find the point and plot it

NB : the code works for a max positive or negative value

load('all_components_values_matlab.mat');

t = Inrushcurrent.Time;
Inrushcurrent = Inrushcurrent.Data ;

plot(t,Inrushcurrent);
title('Inrush current at 0 degrees switching angle')
ylabel('Inrush current [A]')
xlabel('Time [s]')
grid on 
hold on 
 
%Finding the peak (max of absolute value) values of inrush current (positive or negative)
[~,locs] = max(abs(Inrushcurrent));
t_peak = t(locs);
Inrushcurrent_peak = Inrushcurrent(locs);
plot(t_peak,Inrushcurrent_peak,'dr');
text(t_peak+0.05,Inrushcurrent_peak,['Inrush current = ' num2str(Inrushcurrent_peak) ' A']);

[Mathieu NOE]

hello

how is it going ? problem solved ?

[Mathieu NOE]

hello

sorry but again the slx file will not help me

can your share again the data as at file ?

tx

[Mathieu NOE]

sorry there was a typo in my last answer

can you share again the data as mat file ?

Answer 2

[Mathieu NOE]

hello again

so this is the improved version of my code

I also rounded the peak values numbers displayed in the plot

load('all_components_values_matlab.mat');
[samples,phases] = size(Inrushcurrent);
 
%Finding the peak (max of absolute value) values of inrush current (positive or negative)
figure(1)
title('Inrush current at 0 degrees switching angle')

for ci = 1:phases
    [~,locs] = max(abs(Inrushcurrent(:,ci)));
    t_peak(ci) = t(locs);
    Inrushcurrent_peak(ci) = round(Inrushcurrent(locs,ci));
    subplot(phases,1,ci),plot(t,Inrushcurrent(:,ci),t_peak,Inrushcurrent_peak(ci),'dr');
    text(t_peak(ci)*1.05,0.85*Inrushcurrent_peak(ci),['Inrush current = ' num2str(Inrushcurrent_peak(ci)) ' A']);
end
ylabel('Inrush current [A]')
xlabel('Time [s]')

[mart benjamin]

Thank you very much it worked.

[mart benjamin]

Thank you for answering my questions.

Is there a code i can use to detect the time when the transient finally ends (system operating at a rated current __2%-5%). In my case it was 233.3A.

In my code i just used a straight line and data cursor to pin the first stable wave.

Thank you again for taking your time to help me.

[Mathieu NOE]

hello

this would be my suggestion

load('all_components_values_matlab.mat');
[samples,phases] = size(Inrushcurrent);
 
%Finding the peak (max of absolute value) values of inrush current (positive or negative)
figure(1)
title('Inrush current at 0 degrees switching angle')

for ci = 1:phases
    [~,locs] = max(abs(Inrushcurrent(:,ci)));
    t_peak(ci) = t(locs);
    Inrushcurrent_peak(ci) = round(Inrushcurrent(locs,ci));
    % create envelope signal for decay porting
    ind = find(t>=t_peak(ci));
    t_decay = t(ind);
    Inrush_decay = Inrushcurrent(ind,ci);
    % envelope
    N = 500;
    [YUPPER,YLOWER] = envelope(Inrush_decay,N,'peak');
    
    if abs(Inrushcurrent_peak(ci)) > 5000 % decay time computed only for Inrush current exceeding this threshold
        flag(ci) = 1;
        if sign(Inrushcurrent_peak(ci))>0
            envel = YUPPER;
        else
            envel = YLOWER;
        end
        
        ind = find(envel>1.05*envel(end));
        t_end_of_peak(ci) = t(ind(1));
        Inrushcurrent_end_of_peak(ci) = round(Inrushcurrent(ind(1),ci));
    else
        flag(ci) = 0;
        t_end_of_peak(ci) = t_peak(ci);
        Inrushcurrent_end_of_peak(ci) = Inrushcurrent_peak(ci);
    end
    decay_duration(ci) = - t_peak(ci) + t_end_of_peak(ci);
    
    if flag(ci) == 1
        subplot(phases,1,ci),plot(t,Inrushcurrent(:,ci),t_peak,Inrushcurrent_peak(ci),'dr',t_decay,Inrush_decay,...
            t_decay,YUPPER,t_decay,YLOWER,t_end_of_peak(ci),Inrushcurrent_end_of_peak(ci),'dk');
        text(t_peak(ci)*1.05,0.85*Inrushcurrent_peak(ci),['Inrush current = ' num2str(Inrushcurrent_peak(ci)) ' A']);
        text(t_end_of_peak(ci)*1.01,0.15*Inrushcurrent_peak(ci),['Decay Duration = ' num2str(decay_duration(ci)) ' s']);
    else
        subplot(phases,1,ci),plot(t,Inrushcurrent(:,ci),t_peak,Inrushcurrent_peak(ci),'dr',t_decay,Inrush_decay);
        text(t_peak(ci)*1.05,0.85*Inrushcurrent_peak(ci),['Inrush current = ' num2str(Inrushcurrent_peak(ci)) ' A']);        
    end
    
end
ylabel('Inrush current [A]')
xlabel('Time [s]')

[mart benjamin]

thank you very much, it worked. Stay blessed.

[Mathieu NOE]

My pleasure !

would you mind accepting my answer ?

[mart benjamin]

done.

[Mathieu NOE]

thanks