I assume this data is from the Baran, Wu paper [1]. A couple of comments ...

1. Setting RATE_A column to zero is actually correct for a case with no branch flow limits (see footnote 14 at the bottom of p. 49 in the latest User’s Manual). 

2. In the case file you sent, all of the tie lines are in-service, operating as a meshed system, rather than the base radial configuration, and the branch impedance parameters for 5 of the branches (every other branch starting with the first) do not match exactly what’s shown in the paper.

3. I’ve attached attached a version of the case that I believe matches the data from the paper exactly.

4. Unless I’m missing something, the data given in the paper and the base case solution given in the paper are not consistent. For one thing, the voltages do not match, but even more glaring is the fact that the total load is 3715 kW, but they claim the total substation load is 5085.26 kW and that the losses are about 8%. Am I missing something?

    Ray


[1] M. E. Baran and F. F. Wu, "Network reconfiguration in distribution systems for loss reduction and load balancing," in IEEE Transactions on Power Delivery, vol. 4, no. 2, pp. 1401-1407, Apr 1989. doi: 10.1109/61.25627 URL: http://doi.org/10.1109/61.25627

Attachment: case33bw.m
Description: Binary data



On Nov 8, 2016, at 3:07 PM, Haneen Aburub . <[email protected]> wrote:

Thank you so much for your help. It worked now after doing the modifications that you suggested.

On Tue, Nov 8, 2016 at 1:51 PM, André Carvalho Silva <[email protected]> wrote:
Hi there Haneen,

By thaking a quick look at your matpower case, it seems fairly obvious
that the branch flow limits (rate A in MVA) are missing (they cannot
be equal to zero).

Also, you should put some P and Q limits in your generator (Qmin,
Qmax, Pmin and Pmax generator fields).


Best regards,
André Silva



Citando "Haneen Aburub ." <[email protected]>:

> Dear Matpowers,
>
> I tried to run a simple AC OPF for IEEE 33-bus (12.66 kV) distribution
> system using PDIPM solver, but it failed. It gave me the following error:
>
> IPM Numerically Failed: unable to solve Ax=b.
>
> My system has only a generator at bus 1 (ref bus) and a linear cost
> function for that generator.
>
> The AC PF using NR converged fine, but I do not know why the AC OPF did not
> converge?
>
> I tried to relax the voltage limits (0.9-1.1) and using the AC PF solution
> as a start for AC OPF. But these options did not work too.
>
> Could you please help. I attached my case.m file
>
> Best regards,
>
> Haneen
>



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