how to stimulate the effect of shading partial shading on I-V and P-V characteristics?

Hi

I have matlab code to plot I-V and P-V curve. this code run correctly. now i should show effect of shading partial on I-V and P-V curve. I don't know how to add shading partial to this code and which command I shoud use. I have ten module in series which nine of them have full irradiance (S=1,1000W/m2) and one of them has (S=0.5,500w/m2).this is my matlab code. how to add these ten module to this code?

I will appreciate if you could help me.

clear all;close all;clc

%% Characterization Of Photovoltaic Panel Using Single Diode Model

it=input('Enter the number of curves you aim to plot: 1,2...N: ');

for N=1:it;

%% PV Module DATA

T=input('Enter the value of T en C: '); % Temperature of the celle en C

G=input('Enter the value of solar irradiance en W/m2: '); % Solar Irradiance en W/m2

ai=0.034/100; % Current Tmperature coefficient(ki)

av=-0.34/100; % Voltage Tmperature coefficient(kv)

Isc_r=5.3; % Short-circuit current

Voc_r=44.2; % Opent circuit voltage

Vm=36; % Maximum voltage @ STC

Im=4.87; % Maximum current @ STC

Pm=175; % Maximum power @ STC

Ns=72; % nomber of Cells

n=1.3; % Diode ideality factor

%% Internal parameters%%%%%%%%%%%%%

Gr=1000; % reference irradiance

T=T+273.6; %

Tr= 25 +273.6; % Temperature reference

dT=T-Tr;

Isc=Isc_r+ai*dT; % variation of Isc with T

Voc=Voc_r+av*dT; % variation de Vco with T

q=1.60217646*power(10,-19); % charge constant

K=1.3806503*power(10,-23); % Boltzmann constant

Vt=(Ns*n*K*T/q); % Thermal voltage

Eg=1.12; % gap energy

Iph=Isc*(G/Gr); % photo-current

Iss=(Isc)/( exp( Voc/Vt )-1 ); % saturation current

Is=Iss*( (T/Tr)^3 ) * exp ( ( (q*Eg)/(n*K) )*((1/Tr)-(1/T)) );%saturation current

Rs=0.2; % series resistance

Rp=230; % parallele resistance

%%

I=Iph; % initial codition

V=0:(Voc/100):Voc; % input voltage array

for n1=1:length(V)

for n2=1:20 % Newton-Raphson loop for calculating output current

Vd= (V(n1)+Rs*I); % Diode Voltage

Id=Is*( exp(Vd/Vt) -1); % Diode current

Ip=Vd/Rp; % Parallele resistance Current

f=Iph-I-Id-Ip; % f(I)=0

df=-1-(Is*Rs/Vt)*exp(Vd/Vt)-(Rs/Rp); % f'(I)=0

I=I-f/df;% Newton-Raphson formula

end % end of Newton-Raphson

if I<0

I=0;

end

Ipv(n1)=I; % Accumulation of output currant

end

%%

P=Ipv.*V;% Output power

figure(1)

hold on

plot(V,Ipv,'linewidth',N)%

grid on

figure(2)

plot(V,P,'linewidth',N)%

hold on

grid on

end

Answer 1

[Ruchika]

Hi, to add shading to your MATLAB code, you can modify the existing code by introducing a condition that checks whether the module is shaded or not. Here's how you can modify your code to include shading for one module:

clear all; close all; clc

%% Characterization Of Photovoltaic Panel Using Single Diode Model
it = input('Enter the number of curves you aim to plot: 1, 2...N: ');
for N = 1:it
    %% PV Module DATA
    T = input('Enter the value of T in C: ');                      % Temperature of the cell in C
    G = input('Enter the value of solar irradiance in W/m2: ');    % Solar Irradiance in W/m2
    
    ai = 0.034 / 100;     % Current Temperature coefficient (ki)
    av = -0.34 / 100;     % Voltage Temperature coefficient (kv)
    
    Isc_r = 5.3;          % Short-circuit current
    Voc_r = 44.2;         % Open circuit voltage
    Vm = 36;              % Maximum voltage @ STC
    Im = 4.87;            % Maximum current @ STC
    Pm = 175;             % Maximum power @ STC
    Ns = 72;              % Number of cells
    n = 1.3;              % Diode ideality factor
    
    %% Internal parameters
    Gr = 1000;            % Reference irradiance
    T = T + 273.6;
    Tr = 25 + 273.6;      % Temperature reference
    dT = T - Tr;
    Isc = Isc_r + ai * dT;  % Variation of Isc with T
    Voc = Voc_r + av * dT;  % Variation of Vco with T
    
    q = 1.60217646 * power(10, -19);   % Charge constant
    K = 1.3806503 * power(10, -23);    % Boltzmann constant
    Vt = (Ns * n * K * T / q);         % Thermal voltage
    Eg = 1.12;                         % Gap energy
    Iph = Isc * (G / Gr);              % Photo-current
    Iss = (Isc) / (exp(Voc / Vt) - 1); % Saturation current
    Is = Iss * ((T / Tr) ^ 3) * exp(((q * Eg) / (n * K)) * ((1 / Tr) - (1 / T))); % Saturation current
    Rs = 0.2;                          % Series resistance
    Rp = 230;                          % Parallel resistance
    
    %% Shading configuration
    shading = ones(1, 10);     % Initialize shading configuration for 10 modules
    shading(10) = 0.5;         % Set the shading factor for the 10th module to 0.5 (50% irradiance)
    
    I = Iph;                   % Initial condition
    V = 0:(Voc / 100):Voc;     % Input voltage array
    
    for n1 = 1:length(V)
        for n2 = 1:20                          % Newton-Raphson loop for calculating output current
            Vd = (V(n1) + Rs * I);              % Diode Voltage
            Id = Is * (exp(Vd / Vt) - 1);       % Diode current
            Ip = Vd / Rp;                       % Parallel resistance Current
            f = Iph * shading(N) - I - Id - Ip; % f(I) = 0
            
            df = -1 - (Is * Rs / Vt) * exp(Vd / Vt) - (Rs / Rp); % f'(I) = 0
            I = I - f / df; % Newton-Raphson formula
        end % end of Newton-Raphson
        
        if I < 0
            I = 0;
        end
        
        Ipv(n1) = I; % Accumulation of output current
    end
    
    P = Ipv .* V; % Output power
    
    figure(1)
    hold on
    plot(V, Ipv, 'linewidth', N)
    grid on
    figure(2)
    plot(V, P, 'linewidth', N)
    hold on
    grid on
end