Thanks for your help :)
On Thu, Mar 15, 2012 at 3:01 AM, Ray Zimmerman <[email protected]> wrote:
> It should be legitimate to set a generator bus as a PQ bus (i.e. turn off
> any voltage control). This already works as expected I believe.
>
> The bug has to do with the way the voltages are initialized for the AC power
> flow run. For a generator bus that is set as a PQ bus, it should use the
> voltage magnitude in bus(:, VM), but it is currently using the voltage from
> gen(:, VG). For a solved case, the gen(:, VG) value does not contain the
> solved voltage, so running a power flow with the solved case as the input
> does not converge immediately as it should. In fact, in this case, it is
> such a bad starting point that the power flow diverges.
>
> --
> Ray Zimmerman
> Senior Research Associate
> 419A Warren Hall, Cornell University, Ithaca, NY 14853
> phone: (607) 255-9645
>
>
>
>
> On Mar 14, 2012, at 2:40 PM, Kelly, Michael W. wrote:
>
> Is the reason you are considering a bug for MATPOWER is that the 283 PQ
> buses is near the bus limit of the network resulting in little freedom for a
> definitive answer, or is there another reason?
>
> Thanks,
>
> Mike
>
>
> Michael Kelly, Instructor
> Lab FH-449, Office FH-370A
> http://sce.umkc.edu/power/suggestedtexts.aspx
> University of Missouri – Kansas City
> School of Computing & Engineering
> Flarsheim Hall, 5110 Rockhill Road,
> Kansas City, Missouri 64110-2499
> cell (913) 375-6802 / land-line (816) 235-1254 / fax (816) 235-1260
> ________________________________
> From: [email protected]
> [[email protected]] on behalf of Ray Zimmerman
> [[email protected]]
> Sent: Wednesday, March 14, 2012 1:26 PM
> To: MATPOWER discussion forum
> Subject: Re: no solution to DC power flow
>
> You have about 283 generator buses that are marked as PQ buses, rather than
> PV buses. This is what is producing the problem with the AC power flow not
> converging immediately when run using the solution as an input. I think this
> should probably be considered a bug in MATPOWER.
>
> The other thing is that you have 4 lines with zero reactance. That is where
> the NaN's come from in the DC power flow solution. And yes, the DC power
> flow is simply the solution of a linear set of equations, so no iteration is
> necessary.
>
> find(mpc.branch(:, BR_X) == 0)
>
>
> ans =
>
> 3776
> 3784
> 5471
> 5959
>
> --
> Ray Zimmerman
> Senior Research Associate
> 419A Warren Hall, Cornell University, Ithaca, NY 14853
> phone: (607) 255-9645
>
>
