Which file do I need to send you?
please specify it.

Regards
Surbhi Aggarwal


On Tue, Sep 15, 2020 at 7:03 PM Ray Daniel Zimmerman <[email protected]>
wrote:

> 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]>
> 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]>
> 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]>
>> 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]> 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]>
>>> 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]>
>>>> 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]> 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]>
>>>>> 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]>
>>>>>> 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]> 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
>>>>>>>
>>>>>>
>>>>>>
>>>>
>>
>

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