Hello Lawrence,

It is unclear to me which V's are decision variables and which are input's to the model. V seems to be a variable, but are V_in, V_out and V_r inputs to the model? Or do they depend on variables?

But, even then, I feel this could be modelled with Binary variables controlling the limits. Our modelling guide has some tips and tricks on this:

https://download.aimms.com/aimms/download/manuals/AIMMS3OM_IntegerProgrammingTricks.pdf

Since you are new to AIMMS, my suggestion is to take a look at our courses in the academy (they are free!), such as this one:

https://academy.aimms.com/mod/page/view.php?id=177

Also, you can explore the how-to and documentation pages:

https://how-to.aimms.com/

https://documentation.aimms.com/

Hope this helps,

Dear Luispinto,

Thank you for for the response. The Pw(t) is a decision variable in the overall equation as well as the model for other subsystems. This particular subsystem(Wind Turbine) model is based on four different conditions/cases as written.

I appreciate the materials sent as i learnt the concept of a binary variable to set the condition for a two mutually exclusive events. The problem here is four mutually exclusive event. I will appreciate any support i can get. 

Thank you.  

Hello Lawrence,

You can define several binary variables and have only one of them “On” at any given time.

Let's call our auxiliar binary variable W1, W2, W3 and W4 (for each condition).

We can define that W1 + W2 + W3 + W4 = 1, hence only one of them is true (1) at any given time.

Now, you could make constructs that would define when W1,2,3,4 is active, such as:

Vin - V < W1 * Big M (a big number)

Hence, when (Vin - V) is > 0 → W1 will have to be 1

…

Be careful to think through all scenarios, that is, what will all constraints look like when V<Vin, Vin < V < Vr, … They must be aligned to avoid ambiguity.

Cheers,