fm_lf.m

这是一个很适合研究和学习用的电力系统仿真软件

function fm_lf(flag)
% FM_LF compute power flow equations and Jacobian for
%       transmission lines.
%
% FM_LF(FLAG)
%      FLAG = 1: power flow equations
%      FLAG = 2: power flow Jacobian matrix
%
%see also FM_Y and DAE, Bus and Line structures
%
%Author:    Federico Milano
%Date:      11-Nov-2002
%Version:   1.0.0
%
%E-mail:    [e-mail]
%Web-site:  http://thunderbox.uwaterloo.ca/~fmilano
%
% Copyright (C) 2002-2006 Federico Milano

global Bus Line DAE jay Settings

switch flag
 case 1

  DAE.V = max(DAE.V,1e-6);
  Vc = DAE.V.*exp(jay*DAE.a);
  S = Vc.*conj(Line.Y*Vc);
  DAE.gp = real(S);
  DAE.gq = imag(S);
  DAE.glfp = DAE.gp;
  DAE.glfq = DAE.gq;

 case 2

  n = 1:Bus.n;
  U = exp(jay*DAE.a);
  V = DAE.V.*U;
  I = Line.Y*V;

  diagVc = sparse(n,n,V,Bus.n,Bus.n);
  diagVn = sparse(n,n,U,Bus.n,Bus.n);
  diagIc = sparse(n,n,I,Bus.n,Bus.n);

  dS = diagVc * conj(Line.Y * diagVn) + conj(diagIc) * diagVn;
  DAE.J12 = real(dS);
  DAE.J22 = imag(dS) + 1e-6*speye(Bus.n);

  dS = diagVc * conj(diagIc - Line.Y * diagVc);
  DAE.J11 = -imag(dS) + 1e-6*speye(Bus.n);
  DAE.J21 = real(dS);

end