pfsoln

PFSOLN  Updates bus, gen, branch data structures to match power flow soln.
   [BUS, GEN, BRANCH] = PFSOLN(BASEMVA, BUS0, GEN0, BRANCH0, ...
                                   YBUS, YF, YT, V, REF, PV, PQ, MPOPT)

0001 function [bus, gen, branch] = pfsoln(baseMVA, bus0, gen0, branch0, Ybus, Yf, Yt, V, ref, pv, pq, mpopt)
0002 %PFSOLN  Updates bus, gen, branch data structures to match power flow soln.
0003 %   [BUS, GEN, BRANCH] = PFSOLN(BASEMVA, BUS0, GEN0, BRANCH0, ...
0004 %                                   YBUS, YF, YT, V, REF, PV, PQ, MPOPT)
0005 
0006 %   MATPOWER
0007 %   Copyright (c) 1996-2016, Power Systems Engineering Research Center (PSERC)
0008 %   by Ray Zimmerman, PSERC Cornell
0009 %
0010 %   This file is part of MATPOWER.
0011 %   Covered by the 3-clause BSD License (see LICENSE file for details).
0012 %   See http://www.pserc.cornell.edu/matpower/ for more info.
0013 
0014 %% define named indices into bus, gen, branch matrices
0015 [PQ, PV, REF, NONE, BUS_I, BUS_TYPE, PD, QD, GS, BS, BUS_AREA, VM, ...
0016     VA, BASE_KV, ZONE, VMAX, VMIN, LAM_P, LAM_Q, MU_VMAX, MU_VMIN] = idx_bus;
0017 [GEN_BUS, PG, QG, QMAX, QMIN, VG, MBASE, GEN_STATUS, PMAX, PMIN, ...
0018     MU_PMAX, MU_PMIN, MU_QMAX, MU_QMIN, PC1, PC2, QC1MIN, QC1MAX, ...
0019     QC2MIN, QC2MAX, RAMP_AGC, RAMP_10, RAMP_30, RAMP_Q, APF] = idx_gen;
0020 [F_BUS, T_BUS, BR_R, BR_X, BR_B, RATE_A, RATE_B, RATE_C, ...
0021     TAP, SHIFT, BR_STATUS, PF, QF, PT, QT, MU_SF, MU_ST, ...
0022     ANGMIN, ANGMAX, MU_ANGMIN, MU_ANGMAX] = idx_brch;
0023 
0024 %% default options
0025 if nargin < 12
0026     mpopt = mpoption();
0027 end
0028 
0029 %% initialize return values
0030 bus     = bus0;
0031 gen     = gen0;
0032 branch  = branch0;
0033 
0034 %%----- update bus voltages -----
0035 bus(:, VM) = abs(V);
0036 bus(:, VA) = angle(V) * 180 / pi;
0037 
0038 %%----- update Qg for gens at PV/slack buses and Pg for slack bus(es) -----
0039 %% generator info
0040 on = find(gen(:, GEN_STATUS) > 0 & ...  %% which generators are on?
0041         bus(gen(:, GEN_BUS), BUS_TYPE) ~= PQ);  %% ... and not at PQ buses
0042 off = find(gen(:, GEN_STATUS) <= 0);    %% which generators are off?
0043 gbus = gen(on, GEN_BUS);                %% what buses are they at?
0044 
0045 %% compute total injected bus powers
0046 Sbus = V(gbus) .* conj(Ybus(gbus, :) * V);
0047 
0048 %% update Qg for generators at PV/slack buses
0049 gen(off, QG) = zeros(length(off), 1);   %% zero out off-line Qg
0050 %% don't touch the ones at PQ buses
0051 [Pd_gbus, Qd_gbus] = total_load(bus(gbus, :), [], 'bus', [], mpopt);
0052 gen(on, QG) = imag(Sbus) * baseMVA + Qd_gbus;   %% inj Q + local Qd
0053 %% ... at this point any buses with more than one generator will have
0054 %% the total Q dispatch for the bus assigned to each generator. This
0055 %% must be split between them. We do it first equally, then in proportion
0056 %% to the reactive range of the generator.
0057 
0058 if length(on) > 1
0059     %% build connection matrix, element i, j is 1 if gen on(i) at bus j is ON
0060     nb = size(bus, 1);
0061     ngon = size(on, 1);
0062     Cg = sparse((1:ngon)', gbus, ones(ngon, 1), ngon, nb);
0063 
0064     %% divide Qg by number of generators at the bus to distribute equally
0065     ngg = Cg * sum(Cg)';    %% ngon x 1, number of gens at this gen's bus
0066     gen(on, QG) = gen(on, QG) ./ ngg;
0067 
0068     %% divide proportionally
0069     Cmin = sparse((1:ngon)', gbus, gen(on, QMIN), ngon, nb);
0070     Cmax = sparse((1:ngon)', gbus, gen(on, QMAX), ngon, nb);
0071     Qg_tot = Cg' * gen(on, QG);     %% nb x 1 vector of total Qg at each bus
0072     Qg_min = sum(Cmin)';            %% nb x 1 vector of min total Qg at each bus
0073     Qg_max = sum(Cmax)';            %% nb x 1 vector of max total Qg at each bus
0074     ig = find(Cg * Qg_min == Cg * Qg_max);  %% gens at buses with Qg range = 0
0075     Qg_save = gen(on(ig), QG);
0076     gen(on, QG) = gen(on, QMIN) + ...
0077         (Cg * ((Qg_tot - Qg_min)./(Qg_max - Qg_min + eps))) .* ...
0078             (gen(on, QMAX) - gen(on, QMIN));    %%    ^ avoid div by 0
0079     gen(on(ig), QG) = Qg_save;
0080 end                                             %% (terms are mult by 0 anyway)
0081 
0082 %% update Pg for slack gen(s)
0083 for k = 1:length(ref)
0084     refgen = find(gbus == ref(k));              %% which is(are) the reference gen(s)?
0085     Pd_refk = total_load(bus(ref(k), :), [], 'bus', [], mpopt);
0086     gen(on(refgen(1)), PG) = real(Sbus(refgen(1))) * baseMVA + Pd_refk; %% inj P + local Pd
0087     if length(refgen) > 1       %% more than one generator at this ref bus
0088         %% subtract off what is generated by other gens at this bus
0089         gen(on(refgen(1)), PG) = gen(on(refgen(1)), PG) ...
0090                                 - sum(gen(on(refgen(2:length(refgen))), PG));
0091     end
0092 end
0093 
0094 %%----- update/compute branch power flows -----
0095 out = find(branch(:, BR_STATUS) == 0);      %% out-of-service branches
0096 br = find(branch(:, BR_STATUS));            %% in-service branches
0097 Sf = V(branch(br, F_BUS)) .* conj(Yf(br, :) * V) * baseMVA; %% complex power at "from" bus
0098 St = V(branch(br, T_BUS)) .* conj(Yt(br, :) * V) * baseMVA; %% complex power injected at "to" bus
0099 branch(br, [PF, QF, PT, QT]) = [real(Sf) imag(Sf) real(St) imag(St)];
0100 branch(out, [PF, QF, PT, QT]) = zeros(length(out), 4);