What are the cause of the infeasibility ?

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What are the cause of the infeasibility ?

Post by Haithamtaha » 4 months ago

Hello All,

i am working on an optimization problem to maximize an objection function in power system load flow MINLP problem using BONMIN solver. Unfortunately the below message appears when the running process is finished:

EXIT : Converged to a point of local infeasibility. Problem may be infeasible.

The solution summary shows :

**** SOLVER STATUS 1 Normal Completion
**** MODEL STATUS 5 Locally Infeasible
**** OBJECTIVE VALUE 2750.2952

I tried to search for any constraints violation, but i couldn't found.

I appreciate if you can help to find out and resolve the infeasibility issue. I am attaching the GAMS file.

Thanks in advance for your cooperation.
Max. OF .gms
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Re: What are the cause of the infeasibility ?

Post by Renger » 4 months ago

If I run your model with Bonmin, inspecting the listing files gives me

Code: Select all

**** REPORT SUMMARY :       12     NONOPT ( NOPT)
                           292 INFEASIBLE (INFES)
                    SUM     74.671
                    MAX      1.473
                    MEAN     0.256
                             0  UNBOUNDED
                             0     ERRORS
                          4830  PROJECTED
Searching upwards for INFES gives me, for example,

Code: Select all

---- EQU eq6  

          LOWER     LEVEL     UPPER    MARGINAL

8 .t1       .        0.028      .     1000.000 INFES
8 .t2       .        0.003      .     1000.000 INFES
8 .t3       .    6.1595E-4      .     1000.000 INFES
indicating that these constraints are causing problems.
Take a look at this article on fixing your model.

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