An isolated bus is a single bus that does not have any transmission lines connected to it and there are no shunt elements. MATPOWER treats isolated buses as out-of-service buses. In your case the two buses are not isolated, they form an island. So you would need to make one of the buses as the reference bus for that island.
Shri From: Petr Kaplunovich <[email protected]<mailto:[email protected]>> Reply-To: MATPOWER discussion forum <[email protected]<mailto:[email protected]>> Date: Thu, 20 Feb 2014 15:40:50 -0500 To: MATPOWER discussion forum <[email protected]<mailto:[email protected]>> Subject: Re: Case of islanding Thank you! Does two the case of two isolated busses ( busses that are connected to each other but not to the remainder of the grid) counts for isolated buses? Or only single buses do? On Thu, Feb 20, 2014 at 3:37 PM, Abhyankar, Shrirang G. <[email protected]<mailto:[email protected]>> wrote: I believe the power flow and OPF do work for islands provided you have reference bus in each of the islands. One possibility for the solver failure is the presence of isolated buses (buses that do not have any transmission lines connected) in the islands. If there are any isolated buses then you need to set its bus_type=4 in the bus data. BUS_AREA field is only used for petty printing purposes, it is not used in the solution process. Shri From: Petr Kaplunovich <[email protected]<mailto:[email protected]>> Reply-To: MATPOWER discussion forum <[email protected]<mailto:[email protected]>> Date: Thu, 20 Feb 2014 15:15:40 -0500 To: "[email protected]<mailto:[email protected]>" <[email protected]<mailto:[email protected]>> Subject: Case of islanding I have a network with islanding (graph is not connected) and trying to run both DCOPF and DCPF on it. As I found in archives of this list, Prof. Zimmerman replied once that if each island has a reference bus (mpc.bus(i,2)=3) then both functions should work fine. However I keep on getting matrix singularity matlab error for DCPF function and "solution is primal infeasible" for DCOPF function. So the questions are - do DCOPF and DCPF MATPOWER solvers still work for islanding cases? Any thoughts on why I may be getting this errors? Should I set BUS_AREA field? Thank you! Petr
