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optimizationconstraintscplex

CPLEX Constraint with sum operator


Context: I have an optimisation problem, which minimises locations of electric charge stations. Therefore I need a constraint, which calculates the state of charge of one vehicle at a time stamp. I struggle with modelling that constraint.

I have something in mind which looks like this:

for all vehicles and times stateofcharge[vehicle][time] = stateofcharge_start + ((sum up to time)gainedpower[vehicle][time] - (sum up to time)used power[vehicle][time])

I don't know how to put that into code, I tried but it keeps me giving errors.


Solution

  • You could start with

    int nbVeh=6;
    int horizon=10;
    range vehicle=1..nbVeh;
    range time=1..horizon;
    range time0=0..horizon;
    
    float stateofcharge_start[vehicle]=[1,2,3,4,5,6];
    
    
    dvar float+ stateoecharge[vehicle][time0];
    dvar float+ gainedpower[vehicle][time];
    dvar float+ usedpower[vehicle][time];
    
    
    subject to
    {
      forall(v in vehicle) 
        stateoecharge[v][0]==stateofcharge_start[v];
      
      forall(v in vehicle,t in time)  
        stateoecharge[v][t]==stateoecharge[v][t-1]+gainedpower[v][t]-usedpower[v][t];
    }