Unfortunately, the branch flows are non-linear functions of the
optimization variables and are not directly available to apply costs
to them. The best you could do would probably be to apply a cost to
the DC approximation of the branch flow, which is a linear function of
the bus angles, though I'm not sure it makes sense to mix AC and DC
models like this.
In the next version of MATPOWER, the DC OPF also allows for user
variables, constraints and costs to be added, so you could do it all
with a DC OPF in the next version.
--
Ray Zimmerman
Senior Research Associate
428-B Phillips Hall, Cornell University, Ithaca, NY 14853
phone: (607) 255-9645
On Jun 10, 2009, at 9:18 AM, RAVIKUMAR V wrote:
Sir,
Thank you very much for your support. Now I want to minimize
generation cost as well as transmission cost. Obj = sum(fuel
cost) + sum( transmission cost )
where transmission cost = (power flow / line limit) * constant
The fuel cost minimization is already available. Now I want to add
Transmission cost which is depending on Pflow. Is it possible to add
transmission cost in MATPOWER.
On Thu, Mar 26, 2009 at 10:01 PM, Ray Zimmerman <[email protected]>
wrote:
You will need to add some user defined constraints and costs as
described in Section 3.4.1 of the User's Manual.
If you call the base dispatch (where the line overload exists) P0,
then you'll need to define two new variables for each generator, one
Pplus to represent the upward deviation from P0 and another Pminus
to represent the downward deviations. You can put whatever costs on
them you like using the generalized cost function. You'll also need
some extra constraints to define their values ...
Pg - Pplus <= P0
P0 <= Pg + Pminus
0 <= Pplus
0 <= Pminus
You will have to use one of the OPF solvers that uses the
generalized OPF formulation (MINOPF, TSPOPF or fmincon) to solve
this however. You can find an example of a case with extra linear
user constraints & costs in t/t_opf_minopf.m or t/t_opf_fmincon.m.
Hope this helps,
--
Ray Zimmerman
Senior Research Associate
428-B Phillips Hall, Cornell University, Ithaca, NY 14853
phone: (607) 255-9645
On Mar 26, 2009, at 9:44 AM, RAVIKUMAR V wrote:
I am using the lpopf.m file to solve the OPF.
1. case I
for minimizing the cost as objective using lpopf.m . (This is given
directly so I did it.)
2. case II
This is congestion removal by generation resheduling. After adding
bilateral transaction some of the lines get overloaded, In order to
remove this overload, I want to reshedule the generation but the
change is as minimum as possible and given by
f = C( Del (Pg+ )) - C( Del (Pg-))
where C is the cost function for increase/ decrease in generation.
Here I have to solve the OPF by same lp method, but objective is to
reduce the cost for change in generation.
Can I get detailed help for this implementation?
-------------------------------------------------------------
WITH REGARDS,
V.RAVIKUMAR PANDI,
Research Scholar,
-------------------------------------------------------------
HAVE A NICE DAY
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--------------------------------------------------------------
WITH REGARDS,
V.RAVIKUMAR PANDI,
Research Scholar,
-------------------------------------------------------------
HAVE A NICE DAY
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