This indicates a system with 2 isolated buses. As Jubeyer said, you either need
to constrain your switching operations to ensure that you do not create islands
or isolated buses, or you need to check each candidate (e.g. you can use
find_islands() instead of case_info() if you want to do it programmatically)
and eliminate candidates that are not feasible.
Ray
> On Apr 12, 2019, at 5:13 AM, Nitya Kirana <[email protected]> wrote:
>
> Dear all, I just check the case info and it went like this
>
> K>> case_info(hop)
> Checking connectivity ... single connected network, plus 2 isolated buses
> Elapsed time is 0.243862 seconds.
> ================================================================================
> Full Island Isolated
> System 1 Buses
> Number of: ---------- ---------- ----------
> buses 64 62 2
> loads 59 59 -
> on 59 59 -
> off - - -
> fixed 59 59 -
> dispatchable - - -
> on - - -
> off - - -
> generators 3 1 2
> on 3 1 2
> off - - -
> shunt elements - - -
> branches 66 64 -
> on 61 61 -
> off 5 3 -
> ties (off) 2 2 2
>
> Load
> active (MW)
> dispatched 18.2 18.2 -
> fixed 18.2 18.2 -
> dispatchable - - -
> nominal 18.2 18.2 -
> on 18.2 18.2 -
> off - - -
> fixed 18.2 18.2 -
> dispatchable - - -
> on - - -
> off - - -
> reactive (MVAr)
> dispatched 10.9 10.9 -
> fixed 10.9 10.9 -
> dispatchable - - -
> nominal 10.9 10.9 -
> on 10.9 10.9 -
> off - - -
> fixed 10.9 10.9 -
> dispatchable - - -
> on - - -
> off - - -
>
> Generation
> active (MW)
> dispatched - - -
> max capacity - - -
> on - - -
> off - - -
> min capacity - - -
> on - - -
> off - - -
> reactive (MVAr)
> dispatched - - -
> max capacity - - -
> on - - -
> off - - -
> min capacity - - -
> on - - -
> off - - -
>
> Shunt Injections
> active (MW) - - -
> reactive (MVAr) - - -
>
> Branch Losses
> active (MW) - - -
> reactive (MVAr) - - -
>
> DC line
> export (MW)
> dispatch - - -
> max capacity - - -
> on - - -
> off - - -
> min capacity - - -
> on - - -
> off - - -
>
> Reference Buses
> num of ref buses 3 1 2
> ref bus numbers 1 2 1
> 2 3
> 3
>
> So what I need is no isolated bus, how to make the isolated bus becomes non
> isolated bus? thank you.
> On Thu, 11 Apr 2019, 05:04 Carlos A. Castro, <[email protected]
> <mailto:[email protected]>> wrote:
> Dear Putu
>
> I have not run your whole program. I did run a power flow for the 64-bus
> system.
>
> The system is all connected, that is, there are no islands.
>
> The power flow runs smoothly, and converges after 3 iterations. My experience
> shows that Newton's method runs very well for distribution systems, contrary
> to some beliefs. Decoupled methods are the ones that may fail for
> distribution systems.
>
> I would suggest that you debug your program to see whether there is anything
> wrong with it. For instance, suppose that your program defines a branch to be
> opened, causing an island. The power flow would diverge in this situation.
> Actually, Matpower allows you to find it out before running a power flow,
> which is a very good thing to do.
>
> In short, the problem iis certainly not related to the system data.
>
> Regards,
>
>
>
> Em ter, 9 de abr de 2019 às 13:53, Nitya Kirana <[email protected]
> <mailto:[email protected]>> escreveu:
> Dear Carlos,
>
> Here is my program, please run it more than once, because the result will be
> different for every run, thank you.
> Best Regards,
>
> Putu Diah Nitya Kirana,
> Assistant and Researcher at Electric Energy Conversion Laboratory B101
> Electrical Engineering Department
> Faculty of Electrical Technology
> Institut Teknologi Sepuluh Nopember
> Surabaya, Indonesia
> +62 8170 3178 248
>
>
> On Tue, 9 Apr 2019 at 23:39, Carlos A. Castro <[email protected]
> <mailto:[email protected]>> wrote:
> Would you please send me de data file (.m)? I'll try to run it here.
>
> ---------- Forwarded message ---------
> De: Nitya Kirana <[email protected] <mailto:[email protected]>>
> Date: ter, 9 de abr de 2019 às 01:53
> Subject: Re: Network Reconfiguration
> To: MATPOWER discussion forum <[email protected]
> <mailto:[email protected]>>
>
>
> Dear Carlos A. Castro,
>
> Thank you before. I've done the replacement and the buses are all correct,
> because I draw the single line diagram first and then input the data in
> Matlab. Is there any other solution?
> Best Regards,
>
> Putu Diah Nitya Kirana,
> Assistant and Researcher at Electric Energy Conversion Laboratory B101
> Electrical Engineering Department
> Faculty of Electrical Technology
> Institut Teknologi Sepuluh Nopember
> Surabaya, Indonesia
> +62 8170 3178 248
>
>
> On Tue, 9 Apr 2019 at 00:47, Carlos A. Castro <[email protected]
> <mailto:[email protected]>> wrote:
> Dear Nitya
>
> I would do two things:
>
> 1. I would replace all commas "," by points "." in the data file.
>
> 2. I would try to draw the one line diagram of the network based on the data,
> to check whether the network is all connected, that is, that there are no
> isolated buses or group of buses,
>
> Good luck,
>
> Carlos
>
>
> Em seg, 8 de abr de 2019 às 14:42, Nitya Kirana <[email protected]
> <mailto:[email protected]>> escreveu:
> Dear all,
>
> I have run the power flow of 64 radial test bus system using Newton Raphson
> in Matpower 4.1. It shows the result of power losses but it doesn't converge,
> whenever I run the matlab, the result is always different, and I don't know
> what's the problem. Can anyone help me? because this is my final project. It
> shows "Warning: Matrix is singular to working precision."
>
> So, here is my data :
>
> bus data
> bus type Pd Qd
> Gs Bs area Vm Va
> baseKV zone Vmax Vmin
> 1 3 0 0 0 0 1 1 0 20
> 1 1 0,9
> 2 3 0 0 0 0 1 1 0 20
> 1 1 0,9
> 3 3 0 0 0 0 1 1 0 20
> 1 1 0,9
> 4 1 0,0136 0,016256 0 0 1 1 0
> 20 1 1 0,9
> 5 1 0,0204 0,024384 0 0 1 1 0
> 20 1 1 0,9
> 6 1 0 0 0 0 1 1 0 20
> 1 1 0,9
> 7 1 0,07684 0,091846 0 0 1 1 0
> 20 1 1 0,9
> 8 1 0,02856 0,034138 0 0 1 1 0
> 20 1 1 0,9
> 9 1 0,03808 0,045517 0 0 1 1 0
> 20 1 1 0,9
> 10 1 0,0238 0,028448 0 0 1 1 0
> 20 1 1 0,9
> 11 1 0,01768 0,021133 0 0 1 1 0
> 20 1 1 0,9
> 12 1 0,017 0,02032 0 0 1 1 0 20
> 1 1 0,9
> 13 1 0,022304 0,02666 0 0 1 1 0
> 20 1 1 0,9
> 14 1 0,0204 0,002438 0 0 1 1 0
> 20 1 1 0,9
> 15 1 0,05848 0,069901 0 0 1 1 0
> 20 1 1 0,9
> 16 1 0,26384 0,315366 0 0 1 1 0
> 20 1 1 0,9
> 17 1 0,03774 0,04511 0 0 1 1 0 20
> 1 1 0,9
> 18 1 0,0204 0,002438 0 0 1 1 0
> 20 1 1 0,9
> 19 1 0,05576 0,06665 0 0 1 1 0 20
> 1 1 0,9
> 20 1 0,0136 0,016256 0 0 1 1 0
> 20 1 1 0,9
> 21 1 0,0306 0,016256 0 0 1 1 0
> 20 1 1 0,9
> 22 1 0,0204 0,024384 0 0 1 1 0
> 20 1 1 0,9
> 23 1 0,0272 0,032512 0 0 1 1 0
> 20 1 1 0,9
> 24 1 0,11764 0,140614 0 0 1 1 0
> 20 1 1 0,9
> 25 1 0,0068 0,008128 0 0 1 1 0
> 20 1 1 0,9
> 26 1 0,0136 0,016256 0 0 1 1 0
> 20 1 1 0,9
> 27 1 0,0238 0,028448 0 0 1 1 0
> 20 1 1 0,9
> 28 1 0,112948 0,135006 0 0 1 1
> 0 20 1 1 0,9
> 29 1 0,02176 0,02601 0 0 1 1 0 20
> 1 1 0,9
> 30 1 0 0 0 0 1 1 0 20
> 1 1 0,9
> 31 1 0,01768 0,021133 0 0 1 1 0
> 20 1 1 0,9
> 32 1 0,05168 0,061773 0 0 1 1 0
> 20 1 1 0,9
> 33 1 0,03468 0,041453 0 0 1 1 <td
> align="right"
> style="padding-top:1px;padding-right:1px;padding-left:1px;color:black;f
