Storage Constraint

[hamidbardideh]

Dear Carleton

regarding the storage modelling at link below:
https://lanl-ansi.github.io/PowerModels.jl/stable/storage/

I am in doubt about the constraint number (20) considered for the storage. can you please verify if it is correct, and in case, help me to understand it. Thanks in advance

Hamid

[ccoffrin]

Hi Hamid,

I have added some links to the implementation in the docs,
https://lanl-ansi.github.io/PowerModels.jl/dev/storage/

So that you can at least verify that the implementation matches the mathematical model.

To answer your question about understanding (20). This is modeling a 4 quadrant DC to AC inverter with some copper losses (Z*|I|) and standby losses (S^l), the sqc is required to allow for a reactive power set point of the inverter. Note that the active-power-only approximation of this model is much simpler, because all of the reactive power aspects are skipped.

We have a technical report about this model coming out later this week, which derives the model from first principals with detailed explanations. I will post it in this issue once it is available.

[hakanergun]

Hi Carleton,

Should the copper losses not be (Z * | I |^2), I also see it being quadratic in the constraints themselves:
JuMP.@NLconstraint(pm.model,
sum(ps[c] for c in conductors) + (sd - sc)
==
p_loss + sum(r[c]*(ps[c]^2 + qs[c]^2)/vm[c]^2 for c in conductors)
)

[ccoffrin]

Good catch! The docs were incorrect and the implementation is correct, I have fixed the docs.

[ccoffrin]

The detailed derivation of this model is now available here, https://arxiv.org/abs/2004.14768, and I have added a link to this in the docs as well. Shall we close this issue?