Source Code for Module pypower.makeAang

 1  # Copyright (C) 1996-2011 Power System Engineering Research Center (PSERC) 
 2  # Copyright (C) 2011 Richard Lincoln 
 3  # 
 4  # PYPOWER is free software: you can redistribute it and/or modify 
 5  # it under the terms of the GNU General Public License as published 
 6  # by the Free Software Foundation, either version 3 of the License, 
 7  # or (at your option) any later version. 
 8  # 
 9  # PYPOWER is distributed in the hope that it will be useful, 
10  # but WITHOUT ANY WARRANTY; without even the implied warranty of 
11  # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 
12  # GNU General Public License for more details. 
13  # 
14  # You should have received a copy of the GNU General Public License 
15  # along with PYPOWER. If not, see <http://www.gnu.org/licenses/>. 
16   
17  """Construct constraints for branch angle difference limits. 
18  """ 
19   
20  from numpy import array, ones, zeros, r_, Inf, pi, arange 
21  from numpy import flatnonzero as find 
22  from scipy.sparse import csr_matrix as sparse 
23   
24  from idx_brch import F_BUS, T_BUS, ANGMIN, ANGMAX 
25   
26   
27 -def makeAang(baseMVA, branch, nb, ppopt): 
28      """Construct constraints for branch angle difference limits. 
29   
30      Constructs the parameters for the following linear constraint limiting 
31      the voltage angle differences across branches, where C{Va} is the vector 
32      of bus voltage angles. C{nb} is the number of buses:: 
33   
34          lang <= Aang * Va <= uang 
35   
36      C{iang} is the vector of indices of branches with angle difference limits. 
37   
38      @author: Ray Zimmerman (PSERC Cornell) 
39      @author: Carlos E. Murillo-Sanchez (PSERC Cornell & Universidad 
40      Autonoma de Manizales) 
41      @author: Richard Lincoln 
42      """ 
43      ## options 
44      ignore_ang_lim = ppopt['OPF_IGNORE_ANG_LIM'] 
45   
46      if ignore_ang_lim: 
47          Aang  = zeros((0, nb)) 
48          lang  = array([]) 
49          uang  = array([]) 
50          iang  = array([]) 
51      else: 
52          iang = find(((branch[:, ANGMIN] != 0) & (branch[:, ANGMIN] > -360)) | 
53                      ((branch[:, ANGMAX] != 0) & (branch[:, ANGMAX] <  360))) 
54          iangl = find(branch[iang, ANGMIN]) 
55          iangh = find(branch[iang, ANGMAX]) 
56          nang = len(iang) 
57   
58          if nang > 0: 
59              ii = r_[arange(nang), arange(nang)] 
60              jj = r_[branch[iang, F_BUS], branch[iang, T_BUS]] 
61              Aang = sparse((r_[ones(nang), -ones(nang)], 
62                             (ii, jj)), (nang, nb)) 
63              uang = Inf * ones(nang) 
64              lang = -uang 
65              lang[iangl] = branch[iang[iangl], ANGMIN] * pi / 180 
66              uang[iangh] = branch[iang[iangh], ANGMAX] * pi / 180 
67          else: 
68              Aang  = zeros((0, nb)) 
69              lang  = array([]) 
70              uang  = array([]) 
71   
72      return Aang, lang, uang, iang 
73