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
