Home > matpower6.0 > hasPQcap.m

hasPQcap

PURPOSE ^

HASPQCAP Checks for P-Q capability curve constraints.

SYNOPSIS ^

function TorF = hasPQcap(gen, hilo)

DESCRIPTION ^

HASPQCAP  Checks for P-Q capability curve constraints.
   TORF = HASPQCAP(GEN, HILO) returns a column vector of 1's and 0's. The 1's
   correspond to rows of the GEN matrix which correspond to generators which
   have defined a capability curve (with sloped upper and/or lower bound on
   Q) and require that additional linear constraints be added to the OPF.

   The GEN matrix in version 2 of the MATPOWER case format includes columns
   for specifying a P-Q capability curve for a generator defined as the
   intersection of two half-planes and the box constraints on P and Q. The
   two half planes are defined respectively as the area below the line
   connecting (Pc1, Qc1max) and (Pc2, Qc2max) and the area above the line
   connecting (Pc1, Qc1min) and (Pc2, Qc2min).

   If the optional 2nd argument is 'U' this function returns true only for
   rows corresponding to generators that require the upper constraint on Q.
   If it is 'L', only for those requiring the lower constraint. If the 2nd
   argument is not specified or has any other value it returns true for rows
   corresponding to gens that require either or both of the constraints.

   It is smart enough to return true only if the corresponding linear
   constraint is not redundant w.r.t the box constraints.

CROSS-REFERENCE INFORMATION ^

This function calls: This function is called by:

SOURCE CODE ^

0001 function TorF = hasPQcap(gen, hilo)
0002 %HASPQCAP  Checks for P-Q capability curve constraints.
0003 %   TORF = HASPQCAP(GEN, HILO) returns a column vector of 1's and 0's. The 1's
0004 %   correspond to rows of the GEN matrix which correspond to generators which
0005 %   have defined a capability curve (with sloped upper and/or lower bound on
0006 %   Q) and require that additional linear constraints be added to the OPF.
0007 %
0008 %   The GEN matrix in version 2 of the MATPOWER case format includes columns
0009 %   for specifying a P-Q capability curve for a generator defined as the
0010 %   intersection of two half-planes and the box constraints on P and Q. The
0011 %   two half planes are defined respectively as the area below the line
0012 %   connecting (Pc1, Qc1max) and (Pc2, Qc2max) and the area above the line
0013 %   connecting (Pc1, Qc1min) and (Pc2, Qc2min).
0014 %
0015 %   If the optional 2nd argument is 'U' this function returns true only for
0016 %   rows corresponding to generators that require the upper constraint on Q.
0017 %   If it is 'L', only for those requiring the lower constraint. If the 2nd
0018 %   argument is not specified or has any other value it returns true for rows
0019 %   corresponding to gens that require either or both of the constraints.
0020 %
0021 %   It is smart enough to return true only if the corresponding linear
0022 %   constraint is not redundant w.r.t the box constraints.
0023 
0024 %   MATPOWER
0025 %   Copyright (c) 2005-2016, Power Systems Engineering Research Center (PSERC)
0026 %   by Ray Zimmerman, PSERC Cornell
0027 %
0028 %   This file is part of MATPOWER.
0029 %   Covered by the 3-clause BSD License (see LICENSE file for details).
0030 %   See http://www.pserc.cornell.edu/matpower/ for more info.
0031 
0032 [GEN_BUS, PG, QG, QMAX, QMIN, VG, MBASE, GEN_STATUS, PMAX, PMIN, ...
0033     MU_PMAX, MU_PMIN, MU_QMAX, MU_QMIN, PC1, PC2, QC1MIN, QC1MAX, ...
0034     QC2MIN, QC2MAX, RAMP_AGC, RAMP_10, RAMP_30, RAMP_Q, APF] = idx_gen;
0035 
0036 %% default value
0037 if nargin < 2
0038     hilo = 'B';     %% look at both top and bottom by default
0039 end
0040 
0041 %% for which gens is it specified
0042 k = find( gen(:, PC1) | gen(:, PC2) );
0043 ng = size(gen, 1);
0044 
0045 if isempty(k)
0046     TorF = zeros(ng, 1);
0047 else
0048     %% eliminate cases where QMIN = QMAX = QC
0049     kk = find( gen(k, QMIN) == gen(k, QMAX) & ...
0050                 gen(k, QMIN) == gen(k, QC1MAX) & ...
0051                 gen(k, QMIN) == gen(k, QC1MIN) & ...
0052                 gen(k, QMIN) == gen(k, QC2MAX) & ...
0053                 gen(k, QMIN) == gen(k, QC2MIN) );
0054     k(kk) = [];
0055 
0056     %% check for errors in capability curve data
0057     if any( gen(k, PC1) >= gen(k, PC2) )
0058         error('hasPQcap: must have Pc1 < Pc2');
0059     end
0060     if any( gen(k, QC2MAX) <= gen(k, QC2MIN) & gen(k, QC1MAX) <= gen(k, QC1MIN) )
0061         error('hasPQcap: capability curve defines an empty set');
0062     end
0063 
0064     %% for which gens is it specified
0065     k = find( gen(:, PC1) ~= gen(:, PC2) );
0066     L = zeros(ng, 1);
0067     U = zeros(ng, 1);
0068     dPc = gen(k, PC2) - gen(k, PC1);
0069 
0070     if ~strcmp(hilo, 'U')       %% include lower constraint
0071         dQc = gen(k, QC2MIN) - gen(k, QC1MIN);
0072         Qmin_at_Pmin = gen(k, QC1MIN) + (gen(k, PMIN) - gen(k, PC1)) .* ...
0073             dQc ./ dPc;
0074         Qmin_at_Pmax = gen(k, QC1MIN) + (gen(k, PMAX) - gen(k, PC1)) .* ...
0075             dQc ./ dPc;
0076         L(k) = Qmin_at_Pmin > gen(k, QMIN) | Qmin_at_Pmax > gen(k, QMIN);
0077     end
0078 
0079     if ~strcmp(hilo, 'L')       %% include upper constraint
0080         dQc = gen(k, QC2MAX) - gen(k, QC1MAX);
0081         Qmax_at_Pmin = gen(k, QC1MAX) + (gen(k, PMIN) - gen(k, PC1)) .* ...
0082             dQc ./ dPc;
0083         Qmax_at_Pmax = gen(k, QC1MAX) + (gen(k, PMAX) - gen(k, PC1)) .* ...
0084             dQc ./ dPc;
0085         U(k) = Qmax_at_Pmin < gen(k, QMAX) | Qmax_at_Pmax < gen(k, QMAX);
0086     end
0087 
0088     TorF = L | U;
0089 end

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