HARMONIC REDUCTION IN POWER SYSTEM Ankit Vashi B.E. ...

5.3 Matlab Code for Total Harmonic Distortion (THD) Calculation:
% THD calculation
for j=1:length(p1)
add=0;
add1=0;
for i=1:200
c=2*i-1;
amp(c)=(cos(c*p1)+cos(c*p2)+cos(c*p3)+cos(c*p4))/c;
% Calculation of harmonic amplitude
end
for i=2:200
add=amp(i)^2+add;
end
THD(j)=sqrt(add)/amp(1)*100; % THD Phase Voltage calculation
for i=2:100
c=2*i-1;
ck=round(sin(c*2*pi/3)); % Rounding
if ck ~= 0
add1=add1+amp(c)^2;
end
end
THD1(j)=sqrt(add1)/amp(1)*100; % Calculate line voltage THD
End
plot(MI,THD,'c:',MI,THD1,'c');
xlabel('Modulation Index');
ylabel('THD (%)');
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