Battery storage -optimisation problem_charge and discharge

I have seperate decision variables for charge and discharge cosntraints for battery optimisation problem, but i am getting proper value as optimised outputs.

Below is the code :

% initial conditions, battery constraints 
batteryMinMax.Pmin = -500e3;    
batteryMinMax.Pmax = 500e3; 
battEnergy = 3.6e6*upsBattCap;
batteryMinMax.Emax = 0.8*battEnergy;
batteryMinMax.Emin = 0.2*battEnergy;
%Decision variables
PbattchV = optimvar('PbattchV',N,'LowerBound',0,'UpperBound',batteryMinMax.Pmax);
EbattchV = optimvar('EbattchV',N,'LowerBound',0,'UpperBound',batteryMinMax.Emax);
PbattDchV = optimvar('PbattDchV',N,'LowerBound',0,'UpperBound',batteryMinMax.Pmin);
EbattDchV = optimvar('EbattDchV',N,'LowerBound',0,'UpperBound',batteryMinMax.Emin);

Please advice if i made any mistake.

[Alan Weiss]

These two lines are inconsistent:

batteryMinMax.Pmin = -500e3;
PbattDchV = optimvar('PbattDchV',N,'LowerBound',0,'UpperBound',batteryMinMax.Pmin);

You cannot sensibly have a lower bound of 0 and an upper bound of a negative number.

Alan Weiss

MATLAB mathematical toolbox documentation

[NN]

Ok. understood the mistake .Thank you very much Sir

[NN]

i changed the variables and

PbattDchV = optimvar('PbattDchV',N,'LowerBound',-500e3,'UpperBound',0);

But it gives zero output .

Please advice

[Alan Weiss]

Sorry, I don't know what you mean "But it gives zero output." Does it report an error? If so, please copy and paste the entire error message, everything in red. If not, then what is the problem exactly? Does it return a value of zero when you are expecting a nonzero output, or is there something else going on?

Alan Weiss

MATLAB mathematical toolbox documentation

[NN]

yes , it return a value of zero when i expect it to be -500e3

[NN]

Please see the below code :It returns a value of zero ,and i am expecting and output of 500e3 for Pbattups.Please advice.

function [Pd,Pbattups,Ebattups] = battSolarOptimizetrial3(N,dt,Ppv,Pload,Einit,Cost,FinalWeight,upsbatteryMinMax)

prob = optimproblem;
% Decision variables
PdV = optimvar('PdV',N);
PbattupsV = optimvar('PbattupsV',N,'LowerBound',0,'UpperBound'500e3);
EbattupsV = optimvar('EbattupsV',N,'LowerBound',upsbatteryMinMax.Emin,'UpperBound',upsbatteryMinMax.Emax);
% Maximise the profit from the usage of battery and PV
prob.ObjectiveSense = 'minimize';
%prob.Objective = var1 -dt*DayaheadCost'*Ppv-FinalWeight*EbattupsV(N)-FinalWeight*Ebatt1V(N)-FinalWeight*Ebatt2V(N);
prob.Objective =dt*Cost'*PbattupsV- dt*Cost'*Ppv-FinalWeight*EbattupsV(N);
% Power input/output to battery
prob.Constraints.energyBalance = optimconstr(N);
prob.Constraints.energyBalance(1) = EbattupsV(1) == Einit;
prob.Constraints.energyBalance(2:N) = EbattupsV(2:N) == EbattupsV(1:N-1) - PbattupsV(1:N-1)*dt
% Satisfy power load with power from PV, grid and battery
prob.Constraints.loadBalance = Ppv + PdV + PbattupsV == Pload;
%prob.Constraints.battpower = PbattupsV<=500e3;
% Solve the linear program
options = optimoptions(prob.optimoptions,'Display','none');
[values,~,exitflag] = solve(prob,'Options',options);
% Parse optmization results
if exitflag <= 0
    Pd = zeros(N,1);
    Pbattups = zeros(N,1);
    Ebattups = zeros(N,1);
else
    Pd = values.PdV;
    Pbattups = values.PbattupsV; 
    Ebattups = values.EbattupsV;
end

[Walter Roberson]

We do not have the value of the input variables to test with.

[NN]

I have made changes to the example file given below the link .

https://www.mathworks.com/matlabcentral/fileexchange/73139-microgrid-energy-management-system-ems-using-optimization?s_tid=srchtitle

Please see this file and advice

[Walter Roberson]

Which exact file? initial_conditions.m ? If so then are you using the same .mat that is loaded there?

[NN]

battsolar file I have edited according to my model and trying to use

but the files in it which are initial conditions and battsolar can be sued to verify

[Walter Roberson]

You are going to need to tell me which files or data to load and what to pass to battSolarOptimizetrial3

I would suggest writing a script that does the necessary steps.

[NN]

https://www.mathworks.com/matlabcentral/answers/1436322-battery-storage-optimisation-problem_charge-and-discharge-conditional-constraint-nested-function_jn

Please check this link.

[Walter Roberson]

The model there is not compatible with the function at https://www.mathworks.com/matlabcentral/answers/891877-battery-storage-optimisation-problem_charge-and-discharge#comment_1693172 -- the function has fewer inputs than the Simulink model is passing in.