My matlab code for PV P&O tracking algorithm has an error

Hello

I'm writing the code for P&O tracking as I want the output to be Power and Voltage where the max point is located. From the figure, I expected the max power to be at 51.53 W at 16.32 V.

But when I run the code, it always gives the result to the open-circuit voltage (last point of the curve) which is not correct, it gives me the result of 30.01 W at 19 V.

The code that I write is here, not sure I've done something wrong or not (I'm pretty new to matlab). The outputs are P and Vmpp

function [Vmpp,P] =  PandO(V,I)
persistent Vold Pold Iold dV dI dP Power;

if isempty(Vold)
    Vold =0; Iold = 0;
    Pold = 0; dV = 0; dI = 0; dP = 0; Power = zeros(1000,1);
end

deltaV = 0.0001; % initialize

for i = 1:size(V,1)
    Power(i) = V(i) .* I(i);
    dV = V(i) - Vold;
    dI = I(i) - Iold;
    dP = Power(i) - Pold;

      if dP ~= 0
          if dP < 0
              if dV <0
                  Vmpp = V(i) + deltaV;
              else
                  Vmpp = V(i) - deltaV;
              end
          else
              if dV < 0
                  Vmpp = V(i) - deltaV;
              else
                  Vmpp = V(i) + deltaV;
              end
          end
      else
          Vmpp = V(i);
          P = Power(i); 
          break
      end  
          Vold = V(i);
          Iold = I(i);
          Pold = V(i).*I(i);
  end

end

Any suggestion for me? thank you so much in advance

Answer 1

[Roshan Reji]

Did you find the solution please reply asap. I have the same problem.

Answer 2

[mehmet salih fidaner]

Did you find the solution please reply asap. I have the same problem.

[VENKATA ARAVINDA SATVIK MUVVALA]

if you find any solution, please comment here ASAP. I also have same problem.

Answer 3

[M.Saud Khan]

I think the problem is in deltaV. For some reason, my simulation worked with deltaV = 0.04. Decreasing below this value, resulted in Vmpp = open circuit voltage. I have disabled the "zero crossings" in the solver settings & simulated the system using ode23t solver (my system used power electronics blocks; ode23t & ode23tb are mostly used with power electronic blocks).

I'm not a fan of using array indexing & for-loops inside the simulink MATLAB function block. That's why I used the following code:

function [step, flag,Vmpp] = fcn(V,V_old, P,P_old)

flag = 5;                               % Arbitrary
Vmpp = 35;                              % Arbitrary
dV = 0.04;
% persistent Pold Vold dV

if isempty(V_old) || isempty(P_old)
    V_old = 30; P_old = 800;            % Initial conditions
end

delta_P = P - P_old;
delta_V = V - V_old;

if delta_P > 0
    flag = 1;
    if delta_V > 0
        Vmpp = V + dV;                  % Increase voltage
    elseif delta_V < 0
        Vmpp = V - dV;                  % Decrease voltage
    end

elseif delta_P < 0
    flag = -1;
    if delta_V > 0
        Vmpp = V - dV;                  % Decrease voltage
    elseif delta_V < 0
        Vmpp = V + dV;                  % Increase voltage
    end

elseif delta_P == 0
    flag = 0;
    Vmpp = V;
end
step = dV;
end

For V_old & P_old, I used the delay block & to produce the gate signal (duty ratio) of a MOSFET/IGBT, I used a PI controller. The PI gains were selected by hit & trial. All of this is in the picture below:

I have used a flag variable to note the state of delta_P. Results are not very accurate, however, it is working for me..

Hope this helps somebody..

[VENKATA ARAVINDA SATVIK MUVVALA]

is it working for any value of irradiance?

[M.Saud Khan]

Yeah, I have checked with Irr = 1200, 1000, 500, 200 Wb/m2. I don't think the value of irradiance has anything to do with the P&O algorithm. If you are receiving errors on irradinace value, probably check your PV model. I'm using the default Simulink PV model..

[VENKATA ARAVINDA SATVIK MUVVALA]

I am also using the default simulink model but i m getting wrong output. so, Can you please mail me your simulation file. It would be a great help for me to do my assignment.

My mail id: [e-mail]

[Pavani]

Sir, can you please mail me your simulation file.my mail id : [e-mail]

[santosh jaiswar]

can you please mail me that simulation model

[e-mail]

[mehmet salih fidaner]

can you please mail me that simulation model

[e-mail]

[At?l COSGUN]

Could you pls mail me your this study. My mail adress is [e-mail]

[MUSTAFA MOHAMMED]

can you plese mail me [e-mail]

[shobha]

could you please mail this file