IPOPT is not solving

[Karim ElFeky]

Hello Valentin,

I hope this email finds you well. I am an MSc student, currently working on OPF of 4-wire LV distribution networks and I find your work inspiring. I am trying to use ipopt to solve your demo problem on feeder 2 and I have reduced the time interval to 5 minutes and started my simulation at 60 and ended it at 65 (please refer to snip 1). After that, I have removed all the constraints (please refer to snip 2). However, I still get an error that IPOPT can not solve the problem (please refer to snip 3). I have also tried to relax the current mismatch condition to abs(I)<=0.001, but I get the same issue.

Best Regards,

Karim

[valentin...@gmail.com]

Hello Karim,

My first question would be if you had modified anything else in the original scripts. 

Also, there seems to be a problem with the latest version of IPOPT, were you able to run the test scripts that I included in some of the tutorial folders (Test_Pyomo.py)? If not working, download IPOPT 3.11.1 instead. I made a comment on this in the forum a few months ago.

Regards,

V

[Karim ElFeky]

I did not modify the original script at all. except for commenting the knitro and uncommenting the IPOPT lines. I have 3.11.1 compiled version of IPOPT and I ran the test scripts and they are working fine. I have also ran several basic NLP problems using IPOPT from Pyomo- Optimization Modelling in Python book and it is working fine. I have re-written my own power flow pyomo formulation for a 4-wire european network on Pyomo and tried to solved with IPOPT and I get the same error. I am guessing the problem is in the linear solver used by my IPOPT version, did you face problems like that? I am still facing the IPOPT problem, with your script too. Sorry for a lot of text.

Best,

Karim