DefBoundary

 Subroutine DefBoundary indentify the boundary buses in the given model
 mpc based on the list of external buses (ExBus).

   [BoundBus]=DefBoundary(mpc,ExBus)

 INPUT DATA:
   mpc - struct, input system model in MATPOWER format
   ExBus - 1*n array, includes external bus indices
 
 OUTPUT DATA:
   BoundBus - 1*n array, Boundary bus indices

 Note:
   Boundary buses are the retained buses directly connected to external
   buses.

0001 function [BoundBus]=DefBoundary(mpc,ExBus)
0002 % Subroutine DefBoundary indentify the boundary buses in the given model
0003 % mpc based on the list of external buses (ExBus).
0004 %
0005 %   [BoundBus]=DefBoundary(mpc,ExBus)
0006 %
0007 % INPUT DATA:
0008 %   mpc - struct, input system model in MATPOWER format
0009 %   ExBus - 1*n array, includes external bus indices
0010 %
0011 % OUTPUT DATA:
0012 %   BoundBus - 1*n array, Boundary bus indices
0013 %
0014 % Note:
0015 %   Boundary buses are the retained buses directly connected to external
0016 %   buses.
0017 
0018 %   MATPOWER
0019 %   Copyright (c) 2014-2016, Power Systems Engineering Research Center (PSERC)
0020 %   by Yujia Zhu, PSERC ASU
0021 %
0022 %   This file is part of MATPOWER/mx-reduction.
0023 %   Covered by the 3-clause BSD License (see LICENSE file for details).
0024 %   See https://github.com/MATPOWER/mx-reduction/ for more info.
0025 
0026 BoundBus=zeros(size(mpc.bus,1),1);
0027 ExFlag=BoundBus;
0028 ExFlag(ExBus)=1;
0029 
0030 for i = 1:size(mpc.branch,1)
0031     m=mpc.branch(i,1);
0032     n=mpc.branch(i,2);    
0033     if ExFlag(m)+ExFlag(n)<2 % exclude external branch
0034         if (ExFlag(m)*n+ExFlag(n)*m)~=0
0035             BoundBus(ExFlag(m)*n+ExFlag(n)*m)=1;
0036         end
0037     end
0038 end
0039 BoundBus=find(BoundBus==1);
0040 
0041 end