% fonctionnes de commutation convertisseur triphasé six-step PWM. Jesus Morales
% ELE4801. Machines et entraînements électriques.  Hiver 2018.
close all; clear; clc

f = 100;        w = 2*pi*f; 
fsw = 3e3;      wsw = 2*pi*fsw;      Tsw = 1/fsw;        d = 0.75;
dt = 1e-6;      t = 0:dt:1/f;        N = length(t);

s1 = zeros(1,N);   s2 = zeros(1,N);   s3 = zeros(1,N);
c = zeros(1,N);    tri = zeros(1,N);  

for n=1:N
    
    theta = mod(w*t(n)+pi/3,2*pi);
    if theta < pi/3,            s1(n) = 1;      s3(n) = 1;
    elseif theta < 2*pi/3,      s1(n) = 1;
    elseif theta < pi,          s1(n) = 1;      s2(n) = 1;
    elseif theta < 4*pi/3,      s2(n) = 1; 
    elseif theta < 5*pi/3,      s2(n) = 1;      s3(n) = 1;
    elseif theta < 2*pi,        s3(n) = 1;
    end
    
    delta = mod(wsw*t(n),2*pi);
    if delta < pi,        tri(n) = delta/pi;
    else                  tri(n) = 2 - delta/pi;
    end
    
    if d > tri(n),        c(n) = 1;
    end
    
end
s1 = s1.*c;            s2 = s2.*c;            s3 = s3.*c;

figure
subplot(4,1,1); plot(w*t/(pi/3),tri); hold on; 
plot(w*t/(pi/3),ones(1,N)*d); grid; ylim([-0.2 1.2]); title('s_1')
subplot(4,1,2); plot(w*t/(pi/3),s1); grid; ylim([-0.2 1.2]); title('s_1')
subplot(4,1,3); plot(w*t/(pi/3),s2); grid; ylim([-0.2 1.2]); title('s_2')
subplot(4,1,4); plot(w*t/(pi/3),s3); grid; ylim([-0.2 1.2]); title('s_3')