I hadn't thought of limiting the mpc.gen(wind_farm,10) to be equal to
mpc.gen(wind_farm,9). Previously I had mpc.gen(wind_farm,10)=0 , so when wind
output was higher than the total load, simply results.gen(wind_farm,2) was
almost equal to the total load, and the rest of the wind output was curtailed.
Now I tried mpc.gen(wind_farm,10)= mpc.gen(wind_farm,9) so in the results, the
slack bus absorbs the remaining wind power , having a negative output. However
the opf does not converge, and I am sure that this is because of voltage issues.
I have tried to- increase Qmin and Qmax limits (both of the wind farm and the
slack bus), -I have tried relaxing the voltage limits (in the mpc.bus(:,12) and
mpc.bus(:,13)-step down the transformer in the slack bus (by changing the
value of mpc.branch(branch of the transformer 33/11kv, 9)). But still I cannot
succeed convergence.
What more could I try?
From: [email protected]
Subject: Re: how power can be absorbed by the slack bus
Date: Mon, 23 Mar 2015 12:00:53 -0400
To: [email protected]
Have you simply tried it? I can’t think of any reason that a negative output
from the slack bus should cause problems.
Ray
On Mar 20, 2015, at 1:32 PM, angelina sirri <[email protected]> wrote:Dear
all,
I am trying to simulate active network management in distribution network in
11kv. I have a distribution network with 40 nodes. Of those, one node is the
distribution substation node, which is also the slack bus, and also I have in
another node a wind farm.The rest of the nodes are loads. For the cases that I
have a low demand and a wind power output higher than that, I would like to let
the wind farm inject that power back to the main network (which I do not
neither include in the mpc. case , nor simulate).For example, let's say that I
have the following:sum(mpc.bus(:,3))=5MW; %total active demand
sum(mpc.bus(:,4))=4MVar; %total reactive demand
mpc.gen(slack bus,9)=20MW; %maximum slack bus outputmpc.gen(wind_farm,9)=10MW;
%maximum wind power output
So in this case, the wind farm is able to feed the rest of the network, with
zero power taken from the slack bus (if with opf, wind generator is cheaper
than the slack).How could I feed the remaining 5MW (10-5) from the wind farm
back to the grid, getting in the results sth like:results.gen(slack bus,2)=-5MW?
I guess that I will have voltage issues, but in first place I was wandering how
this could happen in case I do not have voltage issues. Afterwards, to face the
voltage issues I was thinking to manually change the tap of the transformer
behind the slack like that:
mpc.branch(branch of the transformer 33/11kv, 9) = range between 0 to 1;
Any proposal would really help!!Kind Regards,Angelina
