>
>The generator voltage was at 2 because i wanted To se if it was à point
>that can help To converge...
Modifying some parameter that violates the physical limits of the system
merely to get solver convergence is not a good
way to approach any problem.
>
>Thank you very much for your explaination about the continuation power
>flow. I tried it and i finally understood it.
>
>So i tried to modify the bus voltage limit, but it's still don't
>converge.
Power flow does not enforce any limits. So modifying the limits will not
change the solution (or the lack of in your case).
>Can we conclude that their is a line in that network that can't handle
>the current that is needed
>to feed the substation down to that line?
>Or am i still missing something?
As I said, the load on your system is more than what the system can
handle. You need to reduce the load (less than 60%) in order
to get a power flow solution.
Shri
>
>
>
>
>
>Le 18/09/2014 00:18, Abhyankar, Shrirang G. a écrit :
>> Ali,
>> Firstly, you have an error in the case file. The generator set point
>> voltage (gen(1,VG) is set to 2 pu which is incorrect. It should be
>> around 1.0 pu.
>>
>> Even after setting the generator set point voltage to 1 pu, the case
>> does not converge because the loading surpasses the steady state
>> loading limit causing a collapse of the bus voltages. You can see this
>> by running the continuation power flow in MATPOWER.
>>
>> mpctarget = case30_1dep;
>> mpcbase = mpctarget;
>> mpcbase.bus(:,[3;4]) = 0.0; %% Set Pd and Qd at all buses to 0.0
>> [RESULTS, SUCCESS] =
>>
>>runcpf(mpcbase,mpctarget,mpoption('cpf.plot.level',1,'cpf.plot.bus',19));
>> % Run a continuation power from base case (Pd/Qd = 0.0) to target
>> (Pd/Qd = given values in case30_1dep).
>>
>> The figure below plots lambda (the load scaling factor in this
>> example) versus bus 19 voltage magnitude. Lambda= 0.0 denotes to the
>> base case having no real and reactive power demand at the buses, while
>> lambda = 1.0 denotes the target demand. As you can see the curve turns
>> around at lambda=0.6 indicating the steady state loading limit has
>> been reached. In other words, this system can only serve 60% of the
>> given target load. Anything above 60% would cause a voltage collapse.
>>
>> You can do similar analysis with your second case and see that lambda
>> goes beyond 1.0 indicating that the extra generation on the downstream
>> bus improves the voltage stability of the system.
>>
>> Shri
>>
>> -----Original Message-----
>> From: ALI ZAZOU Abdelkrim <[email protected]>
>> Reply-To: MATPOWER discussion forum <[email protected]>
>> Date: Wed, 17 Sep 2014 17:36:00 +0200
>> To: <[email protected]>
>> Subject: Convergence and generator
>>
>>> Hi,
>>>
>>> I'm trying to run a simple PF with the newton method, i attached my
>>> case
>>> files with this message.
>>> And i also attached 2 pictures of the network cases.
>>>
>>> I'm working with the case30.m that i modify, i just wanted to use
>>> the
>>> line specifications.
>>> The network now have just 16 bus, 17 branch and 1 Generator(also
>>> slack
>>> bus), and the network is radial.
>>>
>>> 1st problem: The powerflow for this network ("case30_1dep.m")
>>> doesn't
>>> converge and i can't understand why, how can it be explain?
>>>
>>> But it run normally if i add a generator ("case30_1dep_ok.m") that i
>>>
>>> take from the original "case30.m".
>>> So i thought that maybe the slack bus genreation limit is reached
>>> but
>>> even with modyfing the slack bus specification in the
>>> "case30_1dep.m",
>>> it's still doesn't convergent.
>>>
>>> 2nd question: What kind of physical specification (V, P and Q
>>> limits
>>> for example) can affect the convergence.
>>>
>>> Thank you in advance for the time you will take to read my questions
>>>
>>>
>>> Best regards
>>> Abdelkrim Ali Zazou
>>>
>>> .
>>>
>>> The problem is that this loadflow don't converge and i can't
>>> understand
>>> whey,
>>> can you give me some explaination about this issue.
>>>
>>> The problem
>
