matlab optimisation problem _ constraint

Hi, this is a code from matlab optimisation problem given in the below link

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

% Power input/output to battery
prob.Constraints.energyBalance = optimconstr(N);
prob.Constraints.energyBalance(1) = EbattV(1) == Einit;
prob.Constraints.energyBalance(2:N) = EbattV(2:N) == EbattV(1:N-1) - PbattV(1:N-1)*dt;

please explain what it means!

Answer 1

[Walter Roberson]

A problem is being constructed. It has constraints. One constraint is named energyBalance .

The first line, optimconstr(N) says that a constraint with N parts is being constructed.

The assignment to energyBalance(1) says that the first constraint is that the first battery voltage must be a particular initial condition.

The assignment to energyBalance(2:N) says that the next N-1 constraints are that the battery voltages must decrease each time by Pbattv*dt .