Re: CPU time

[Abhyankar, Shrirang G]

Ahmad,
Can you be more specific with your question. How big of a system are you 
planning to solve? Do you need to perform the CPF run within some stipulated 
time?

CPF basically solves a series of power flow solutions given some transfer 
direction. Roughly, its computational complexity equals the number of power 
flow solutions (CPF steps) + an additional overhead for computing the tangent 
vector. There are a couple of things one can do to run the CPF faster:


i)Increase the step-size (mpopt.cpf.step): A larger 
step-size would result in fewer CPF steps and in turn fewer power flow 
solutions. However, increasing the step-size also means that the CPF may need 
to do additional iterations at each step.

ii)   Use step adaptivity (mpopt.cpf.adapt_step): The CPF will 
adaptively change the step-size when this option is turned ON. It will take 
larger steps on the flat portion of the PV curve and small steps for larger 
curvatures. One can limit the max. and min. step with the options 
mpopt.cpf.step_max and mpopt.cpf.step_min.

Shri


From:  on behalf of Ahmad Sadiq 
Abubakar 
Reply-To: MATPOWER discussion forum 
Date: Friday, April 12, 2019 at 12:44 AM
To: MATPOWER discussion forum 
Subject: CPU time

Hi all,

What do you think will be the effect of CPF run of a real power systems with 
large number of buses on CPU time?

I mean MATPOWER's continuation power flow (CPF)

Kind regards
Ahmad.

Re: case300 problem

[Abhyankar, Shrirang G]

Naime,
   The bus numbers given in the casefile, “external bus numbers”, need not be 
consecutive integers from 1..nbus. These can be any integers. Internally, 
MATPOWER converts them to “internal numbering” (consecutive integers from 
1..nbus).  If you want to operate with internal numbers then use the 
ext2int
 routine.

mpc = loadcase(‘casename’);
mpc_int = ext2int(mpc);

Shri

From:  on behalf of naime ahmadi 

Reply-To: MATPOWER discussion forum 
Date: Friday, April 12, 2019 at 12:13 AM
To: MATPOWER discussion forum 
Subject: case300 problem

Hi,
I have a question about 300 bus system. When I opened the case300, in bus data 
I saw 1190 as bus number. or in branch data, bus 9001 is connected to 9005. As 
case300 has only 300 bus so what is 1190 and 9001?
How can I fix this case?
Thanks,
Naime

Re: Network Reconfiguration

[Nitya Kirana]

Dear all, I just check the case info and it went like this

K>> case_info(hop)
Checking connectivity ... single connected network, plus 2 isolated buses
Elapsed time is 0.243862 seconds.

Full   Island Isolated
   System 1 Buses
Number of:   --  --  --
  buses64  62   2
  loads59  59   -
on 59  59   -
off -   -   -
fixed  59  59   -
dispatchable-   -   -
  on-   -   -
  off   -   -   -
  generators3   1   2
on  3   1   2
off -   -   -
  shunt elements-   -   -
  branches 66  64   -
on 61  61   -
off 5   3   -
ties (off)  2   2   2

Load
  active (MW)
dispatched 18.218.2 -
  fixed18.218.2 -
  dispatchable  -   -   -
nominal18.218.2 -
  on   18.218.2 -
  off   -   -   -
  fixed18.218.2 -
  dispatchable  -   -   -
on  -   -   -
off -   -   -
  reactive (MVAr)
dispatched 10.910.9 -
  fixed10.910.9 -
  dispatchable  -   -   -
nominal10.910.9 -
  on   10.910.9 -
  off   -   -   -
  fixed10.910.9 -
  dispatchable  -   -   -
on  -   -   -
off -   -   -

Generation
  active (MW)
dispatched  -   -   -
max capacity-   -   -
  on-   -   -
  off   -   -   -
min capacity-   -   -
  on-   -   -
  off   -   -   -
  reactive (MVAr)
dispatched  -   -   -
max capacity-   -   -
  on-   -   -
  off   -   -   -
min capacity-   -   -
  on-   -   -
  off   -   -   -

Shunt Injections
active (MW) -   -   -
reactive (MVAr) -   -   -

Branch Losses
active (MW) -   -   -
reactive (MVAr) -   -   -

DC line
  export (MW)
dispatch-   -   -
max capacity-   -   -
  on-   -   -
  off   -   -   -
min capacity-   -   -
  on-   -   -
  off   -   -   -

Reference Buses
  num of ref buses  3   1   2
  ref bus numbers   1   2   1
2   3
3

So what I need is no isolated bus, how to make the isolated bus becomes non
isolated bus? thank you.
On Thu, 11 Apr 2019, 05:04 Carlos A. Castro,  wrote:

> Dear Putu
>
> I have not run your whole program. I did run a power flow for the 64-bus
> system.
>
> The system is all connected, that is, there are no islands.
>
> The power flow runs smoothly, and converges after 3 iterations. My
> experience shows that Newton's method runs very well for distribution
> systems, contrary to some beliefs. Decoupled methods are the ones that may
> fail for distribution systems.
>
>  I would suggest that you debug your program to see whether there is
> anything wrong with it. For instance, suppose that your program defines a
> branch to be opened, causing an island. The power flow would diverge in
> this situation. Actually, Matpower allows you to find it out before running
> a power flow, which is a very good thing to do.
>