Hi,
Thank you very much for answering so quickly, i'm sorry for the delay in
my answer i di n t have access To MATLAB.
The generator voltage was at 2 because i wanted To se if it was à point
that can help To converge...
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.
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?
Tank you very much for your help,
it's really great To find a free performant tool anda community of
qualified helpers, i hope in the future i will be able To help like you
did forme.
Best Regards
Abdelkrim
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
