Looks like the Jacobian is singular. Feel free to send me the case (off-list)
and I’ll have a look.
Ray
On Sep 14, 2020, at 11:35 PM, Surbhi Aggarwal
<[email protected]<mailto:[email protected]>> wrote:
Even after doing everything, this error prompts out.
Please help me out with this issue.
Warning: Matrix is singular to working precision.
> In mplinsolve (line 75)
In newtonpf (line 110)
In runpf (line 260)
Regards
Surbhi Aggarwal
On Mon, Sep 14, 2020 at 7:31 PM Ray Daniel Zimmerman
<[email protected]<mailto:[email protected]>> wrote:
You would have to confirm the cause of the non-convergence before drawing any
conclusions. You may find FAQ #5<https://matpower.org/doc/faq/#pfconvergence>
helpful.
Ray
On Sep 12, 2020, at 6:43 AM, Surbhi Aggarwal
<[email protected]<mailto:[email protected]>> wrote:
Hello
If the system does not converge within 10 iterations, can we say that it is one
of the most severely affected lines in contingency studies?
Or any other explanation for this non-convergence?
Regards
Surbhi Aggarwal
On Sat, Sep 12, 2020 at 10:40 AM Surbhi Aggarwal
<[email protected]<mailto:[email protected]>> wrote:
Hello
Thank you all for your help and I'll definitely look out for the solutions.
Thank you so much
Regards
Surbhi Aggarwal
On Fri, Sep 11, 2020 at 7:16 PM Ray Daniel Zimmerman
<[email protected]<mailto:[email protected]>> wrote:
Hi Surbhi,
It looks like you were using the default Newton power flow. To increase the
number of iterations, you can increase the pf.nr.max_it option. However, this
is rarely necessary. If the Newton method is going to converge, it usually does
so in less than the default 10 iterations. If it is not converging within 10
iterations, it is likely that the problem has no solution or that you need a
better starting point.
Ray
On Sep 11, 2020, at 5:48 AM, Mirish Thakur
<[email protected]<mailto:[email protected]>> wrote:
Hi Surbhi,
First of all why do you want to increase the number of steps/ iterations in the
calculation? Is there any specific need? Actually the number of iterations
depends on the power flow optimization tolerance. Maybe you can focus on the
mpoption function and read it carefully. You can update something like here:
mpopt = mpoption('pf.alg', 'FDXB', 'pf.tol', 1e-4)
I'm not 100 % sure about it but it may help you. Thanks.
Kind regards
Mirish
On Fri, Sep 11, 2020 at 8:41 AM Surbhi Aggarwal
<[email protected]<mailto:[email protected]>> wrote:
Hello Everyone,
I tried your suggestions and it somehow helped me.
Now my doubt is " If I want to increase my number of iterations, what steps I
have to do"?
Please help me out
Regards
Surbhi Aggarwal
On Wed, Sep 9, 2020 at 7:50 PM Ray Daniel Zimmerman
<[email protected]<mailto:[email protected]>> wrote:
I also suspect that the network becomes disconnected by removing certain lines.
You can check the connectivity using
case_info()<https://matpower.org/docs/ref/matpower7.0/lib/case_info.html> or
find_islands()<https://matpower.org/docs/ref/matpower7.0/lib/find_islands.html>.
If there are islands, then each island needs to have its own reference bus,
and the local generation needs to be able to meet the local load in each island.
Ray
On Sep 9, 2020, at 4:57 AM, Mirish Thakur
<[email protected]<mailto:[email protected]>> wrote:
Hi Surbhi,
Could you please check the continuity of the system before running opf? I mean
to say if you run opf for (n-1) criteria the system should be still well
connected. There shouldn't be any island within the system itself. Perhaps you
can test your model by removing any one parallel line (which you can observe
later for analysis) and run the model under (n-1) criteria. This could be the
easiest way to test the model. Thank you.
Kind regards
Mirish
On Wed, Sep 9, 2020 at 9:11 AM Surbhi Aggarwal
<[email protected]<mailto:[email protected]>> wrote:
Dear All,
I am working on optimal power flow to find the contingency (N-1) situation of
the system. For some of the line outage, certain output pops out
MATPOWER Version 7.0, 20-Jun-2019 -- AC Power Flow (Newton)
Warning: Matrix is singular to working precision.
> In mplinsolve (line 75)
In newtonpf (line 110)
In runpf (line 260)
Warning: Matrix is singular to working precision.
> In mplinsolve (line 75)
In newtonpf (line 110)
In runpf (line 260)
Warning: Matrix is singular to working precision.
> In mplinsolve (line 75)
In newtonpf (line 110)
In runpf (line 260)
Warning: Matrix is singular to working precision.
> In mplinsolve (line 75)
In newtonpf (line 110)
In runpf (line 260)
Warning: Matrix is singular to working precision.
> In mplinsolve (line 75)
In newtonpf (line 110)
In runpf (line 260)
Warning: Matrix is singular to working precision.
> In mplinsolve (line 75)
In newtonpf (line 110)
In runpf (line 260)
Warning: Matrix is singular to working precision.
> In mplinsolve (line 75)
In newtonpf (line 110)
In runpf (line 260)
Warning: Matrix is singular to working precision.
> In mplinsolve (line 75)
In newtonpf (line 110)
In runpf (line 260)
Warning: Matrix is singular to working precision.
> In mplinsolve (line 75)
In newtonpf (line 110)
In runpf (line 260)
Warning: Matrix is singular to working precision.
> In mplinsolve (line 75)
In newtonpf (line 110)
In runpf (line 260)
Newton's method power flow (power balance, polar) did not converge in 10
iterations.
>>>>> Did NOT converge (7.38 seconds) <<<<<
What to do to correct this error. It would be of great help.
Regards
Surbhi Aggarwal
