I have been trying to code a solar pv module for 1 diode model, the following is my code, can someone tell me the mistake ive made and the correction to it pls.

clc;

clear all;

Pmpp = 50; %Max Power

Vmpp = 17.98; %Vol at Pmax

Impp = 2.77; %Current at Pmax

Isc= 3; %Short-circuit current

Voc= 22; %Open Circuit Voltage

a= 0.0004; %Temp coeff. of Isc

b= -0.0033; %Temp coeff. of Voc

T = 28;

Tref= 25;

S= 800;

Sref= 1000;

Rs= 0.085;

V= 20;

kref= (((Vmpp+Rs*Impp)/Voc)-1)*(1-(Impp/Isc))^0.5;

Vo = Voc*(1+ a*log(S/Sref)+ b*(T-Tref));

I= zeros(330,1);

i=1;

I(1,1)=0;

for V= 32.9:-0.1:0

Is = Isc*(1+a(T-Tref))*(S/Sref);

I(i,1)= Isc(1-kref.^((V-Voc+Rs*I)/Voc));

i=i+1;

end

Answer 1

[Alan Stevens]

Like this? Note: I've made kref positive to avoid the I's being complex. This might be completely incorrect!!

Pmpp = 50;        %Max Power
Vmpp = 17.98;     %Vol at Pmax
Impp = 2.77;      %Current at Pmax
Isc= 3;           %Short-circuit current
Voc= 22;          %Open Circuit Voltage
a= 0.0004;        %Temp coeff. of Isc
b= -0.0033;       %Temp coeff. of Voc
T = 28;
Tref= 25;
S= 800;
Sref= 1000;
Rs= 0.085;
V= 20;
kref= -(((Vmpp+Rs*Impp)/Voc)-1)*(1-(Impp/Isc))^0.5;  %%%% Made kref positive
Vo = Voc*(1+ a*log(S/Sref)+ b*(T-Tref));
I= zeros(330,1);

for i = 1:330
    V(i)= (i-1)*0.1;
    Is = Isc*(1+a*(T-Tref))*(S/Sref);        %%%%  a*(T-Tref)
    I(i)= Isc*(1-kref.^((V(i)-Voc+Rs*I(i))/Voc)); %%%% Isc*(1-etc.  and I(i)
end
plot(V,I),grid
xlabel('V'),ylabel('I')

[Aryan Sharma]

Thx alan, you helped me identify my mistake.

P.S: I had applied wrong equation for kref thats why the plot was coming wrong