| Hi Sir. I hope you are doing well. If EVs are to be added as loads on buses that ave P and Q. Should the load be added in bus data or should I be added as shunt element or can it be used as negative generator?
From: Ray Daniel Zimmerman Sent: Wednesday, 8 November 2023 9:14 PM To: MATPOWER-L Reply To: MATPOWER discussion forum Subject: Re: Finding the maximum positive (and negative) power injection at a bus |
See Section 6.4.2 on Dispatchable Loads in the MATPOWER
User’s Manual. A dispatchable load is exactly what you are looking for. It’s a negative generator with a constant power factor constraint. Any generator with PMIN < 0 and PMAX == 0 will be treated as a dispatchable load and the constant power factor constraint
will be added automatically.
Ray
Dear MATPOWER team,
In connection with placing a dummy generator to maximize/minimize the power injection at the bus of interest, is it also possible in MATPOWER to impose a power factor constraint on the said dummy generator?
Examples:
- Scenario 1: minimize the negative power injection in bus X, with a power factor constraint of 0.80 lagging pf.
- Scenario 2: minimize the negative power injection in bus X, with a power factor constraint of 0.80 leading pf.
That’s correct. Except, if you are zeroing out all other costs, there is no need to use such a huge magnitude for the cost. Any reasonable non-zero number would do (like 10 or 100). When the problem includes coefficients with huge ranges it can potentially
result in numerical issues.
Ray
Hi sir,
Thanks for the suggestion!
Let me confirm my understanding:
1. Create a dummy generator with the following limits: -99999 MW <= Pdummy <= 99999 MW
2. To minimize the injection, set a very large positive cost coefficient (C = 99999Pdummy) and zero out all other costs, turning the objective function to: min (99999Pdummy + 0Pg1 + 0Pg2 + ...)
3. To maximize the injection, set a very large negative cost coefficient (C = -99999Pdummy) and zero out all other costs, turning the objective function to: min (-99999Pdummy + 0Pg1 + 0Pg2 + ...)
4. Retain all other information
Thanks in advance!
You can do this by placing a dummy generator at the bus of interest and using a very large negative (to maximize the injection) or positive (to minimize the injection) generation cost. You can either zero out all other costs, or simply make the magnitude of
the cost large enough to dominate all other costs.
Ray
> On Oct 5, 2023, at 8:48 PM, Ronald Cabaoig <[email protected]> wrote:
>
> Dear MATPOWER team,
>
> Greetings!
>
> In the current MATPOWER version, is it possible to reformulate the objective function to find the maximum positive (and negative) power injection in a certain bus:
>
> Maximize the positive power injection in bus X (or could also be: minimize the negative power injection in bus X)
> Subject to the AC power flow equations, branch flow limits, generator output limits, voltage limits.
>
> The main decision variable in this case would be the power injection in bus X. Other values that could vary are the generator outputs, voltages, and the like (all subject to the constraints).
>
> Cheers,
> Ronald
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