When we set R=0, it makes power losses =0 
What I am trying to accomplish is to see the power flows (P,Q) through the 
lines, but without considering losses. 
DCOPF does not show the Q flows in the lines. So I want a ACOPF. 

In other words, say we have a bus with one generator. We have also a load of 
100MW, 100MVAr. So the generator produces 100MW and 100MVAr (ie no P , Q 
losses) . There are 2 lines from the generator bus and say that the flow from 
each line is 50MW, and 50MVAr.  And we also get the |V| and the voltage angles 
as well.

This is what I want. To see the flows through the lines, without considering P 
losses and Q losses.
By setting R=0, we accomplish the first objective:  not to have P losses. 
How can I make Q losses zero as well?

Thank you





________________________________
 From: Ray Zimmerman <[email protected]>
To: MATPOWER discussion forum <[email protected]> 
Sent: Tuesday, April 16, 2013 9:58 PM
Subject: Re: Ignoring losses
 


I find it difficult to believe that setting R=0 makes the real power *flows* 
zero … I assume you meant real power *losses*.

I'm not sure what you are trying to accomplish … but I agree that setting X = 0 
is not going to be realistic. I'm not sure there is a "realistic" model where 
voltages are not 1 and reactive losses are zero. But this is not strictly a 
MATPOWER question and should probably be addressed in another forum.

-- 
Ray Zimmerman
Senior Research Associate
419A Warren Hall, Cornell University, Ithaca, NY 14853
phone: (607) 255-9645




On Apr 16, 2013, at 2:53 PM, Aftognosia Aftognosia <[email protected]> wrote:

Dear Dr Zimmerman,
>
>
>By setting r=0 , for the branches, the real power flows are zero. 
>But the reactive power flows are not zero. 
>When I set X=0, the voltage magnitudes become 1, and generally the results are 
>not realistic. 
>
>
>How can I set the Reactive power losses = 0 ?
>
>
>I would not like to move to DCOPF, because this formulation ignores Q flows, 
>and sets voltage magnitudes=1.
>
>
>Thank you
>
>
>
>________________________________
> From: Ray Zimmerman <[email protected]>
>To: MATPOWER Discussion List <[email protected]> 
>Sent: Tuesday, April 9, 2013 7:37 PM
>Subject: Re: Ignoring losses
> 
>
>
>One way is to simply zero out the R data for the branches …
>
>
>define_constants;
>mpc = loadcase('mycase');
>mpc.branch(:, BR_R) = 0;
>r = runopf(mpc);
>
>
>Another is to simply use a DC OPF which is based on a lossless, linear 
>approximation of the network model.
>
>
>r = rundcopf(mpc);
>
>
>-- 
>Ray Zimmerman
>Senior Research Associate
>419A Warren Hall, Cornell University, Ithaca, NY 14853
>phone: (607) 255-9645
>
>
>
>
>On Apr 5, 2013, at 11:28 PM, Aftognosia Aftognosia <[email protected]> 
>wrote:
>
>Hello.
>>Congratulations for this list and for the matpower community ! 
>>
>>I am trying to formulate an OPF problem on matpower.
>>I receive the results but I would like to ignore losses!
>>
>>I.e. I am giving the data for r and for x , but I would like to ignore the 
>>losses.
>>How can I ignore the losses please?
>>
>>Thank you
>>John Eaftos
>>NTUA
>>
>>
>>
>
>
>

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