Aw: Re: CPF-Q-Limit

[Thomas Jäckel]

 

Thank you for your quick answer.

Do you already have a release-date for the new version? This would be very interesting, because I am currently working at this for my master-thesis. So it would be useful to know if the new version will be released in time or I have to create the code by myself.

 

Greetings

Thomas

 

Gesendet: Donnerstag, 23. Juni 2016 um 17:36 Uhr
Von: "Ray Zimmerman" <r...@cornell.edu>
An: "MATPOWER discussion forum" <matpowe...@list.cornell.edu>
Betreff: Re: CPF-Q-Limit

Thank you Thomas. As we speak, I am working on integrating and testing code from Shri (who implemented the initial CPF code) to add generator P and Q limiting in the CPF. It will hopefully be available in v6.0b2 shortly.

 

    Ray

 

 

 

On Jun 23, 2016, at 7:40 AM, Thomas Jäckel <jaeckel.tho...@gmx.net> wrote:

 

Dear Mr. Zimmermann, dear all,

 

I have another few questions concerning the limits of reactive power generation within the CPF. I created a code by myself which should implement the limits:

 

1. After every corrector-step the code checks if any reactive power limits of the generators were exceeded.

2. If "no" – go on, if "yes" then the following steps are done:

3. Identify the generators, which exceed their reactive power limit and set the corresponding value (Q_g) to the limit of the generator. Afterwards, the corresponding bus is converted to a pq-bus.

4. Update Sbusb with the new busb and genb, update Sbust with the new bust and gent. Update Sxfr (which should still be the same). Update bus_types-list.

5. If the ref-bus was exceeded then chose a new ref-bus and adjust the voltage-angle. The angle for the ref-bus is “0” and the length is “1”. The other buses are shifted accordingly.

6. Go back to the previous corrector-step and start the step with new stats.

 

So when the new the next step predictor and corrector step starts the following values have changed: Sbusb, V0, Vprv, ref, pv and pq.

So in my opinion it should be able to determine the next corrector-step with the new information.

Unluckily it doesn't work because the corrector-step does not convert, I tested the additions with case9.m. Remarkable is the change in lambda, during the normal cpf-procedure it gets continuously larger, but if a reactive power limit is exceeded and my code is applied, lambda gets negative – I do not know why.

 

I attached the code if you need to have a closer look. The qlimit-code is applied between 277 and 431.

 

Thank you very much for your help

 

Kind regards,

 

Thomas

<runcpf_with_qlim.m>