how to solve the equation mentioned below by plotting curve with fzero solve?

how to solve the equation of I-V characteristics of solar cell mentioned below by plotting curve using fzero function?

I=Ipv-Io*exp((V+I*Rs)/(a*Vt))-((V+I*Rs)/Rsh)

[Birdman]

What are the values for the parameters other than I and V?

Answer 1

[Shishir Reddy]

Hi Tanvir

To solve the implicit equation for the I-V characteristics of a solar cell using 'fzero', you can define the equation as a function of current 'I' for a given voltage 'V', and then solve for 'I' at each voltage point as shown in the code snippet below -

Ipv = 5; Io = 1e-10; Rs = 0.2; Rsh = 1000; a = 1.3; Vt = 0.0259;

V = linspace(0, 0.7, 100);
I = zeros(size(V));

% Solve I for each V using fzero
for k = 1:length(V)
    Vk = V(k);
    fun = @(I) I - Ipv + Io * exp((Vk + I*Rs)/(a*Vt)) + (Vk + I*Rs)/Rsh;
    I(k) = fzero(fun, Ipv);  % Ipv is a good initial guess
end

% Plot
plot(V, I, 'LineWidth', 2);
xlabel('Voltage (V)'); ylabel('Current (A)');
title('I-V Characteristics of Solar Cell'); grid on;

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For more information regarding 'fsolve' function, kindly refer the following documentation - https://www.mathworks.com/help/optim/ug/fsolve.html

I hope this helps.