if else then else condition as constraint/variable, multi-objective optimisation, robust/stochastic optimisation

  • 12 June 2023
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Dear AIMMS team,

 

I trust this meets you well. Thank you for all your support. My challenge is multifaceted. 

 

I am building AIMMS code to optimize hybrid energy system just as it is presented in the 'calc' sheet of the attached Excel file. The two AIMMS folders attached show how I have attempted to reproduce the 'calc sheet' functions in AIMMS, but below are the comments from AIMMS after running them:  

 

''The definition of constraint 'Constraint_2(01)' contains an if-then-else statement with a variable in the condition, which cannot be handled by OCTERACT.''

 

''The definition of constraint 'Positive_Energy_Difference_kW_definition(01)' contains an if-then-else statement with a variable in the condition, which cannot be handled by OCTERACT.''

 

All the column functions (in Excel 'calc' tab) are represented in AIMMS. It appears the way I have written the conditional statements in the two AIMMS folders is not allowed. Kindly assist further. 

 

Please note: The AIMMS data file for both AIMMS folders that should be loaded into active is 'Testing.data'. 

 

I will like to ask two more questions about the challenge I have shared above. 

 

1. If I want to perform multi-objective optimization (two objectives), do I have to add another aimms variable and mathematical program to contain the second objective, or do I add it to the aimms variable containing the first objective but with weighting factors? Please help I need clarification on how to use AIMMs to perform multi-objective optimization.  

 

2. In the case of introducing uncertainty to three parameters (Load(t), windspeed(t) and Solar_Irradiation_Wperm2(t)) in order to perform stochastic optimization and robust optimization, in what way can this be carried out? 

 

I will also appreciate any comprehensive material I can use to gain more understanding. 

 

 

Thank you so much.


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