getV0

GETV0  Get initial voltage profile for power flow calculation.
   Note: The pv bus voltage will remain at the given value even for
   flat start.
   type_initialguess: 1 - initial guess from case data
                      2 - flat start
                      3 - from input

0001 function V0 = getV0(bus, gen, type_initialguess, V0)
0002 %GETV0  Get initial voltage profile for power flow calculation.
0003 %   Note: The pv bus voltage will remain at the given value even for
0004 %   flat start.
0005 %   type_initialguess: 1 - initial guess from case data
0006 %                      2 - flat start
0007 %                      3 - from input
0008 
0009 %   MATPOWER
0010 %   Copyright (c) 2009-2016, Power Systems Engineering Research Center (PSERC)
0011 %   by Rui Bo
0012 %
0013 %   This file is part of MATPOWER.
0014 %   Covered by the 3-clause BSD License (see LICENSE file for details).
0015 %   See http://www.pserc.cornell.edu/matpower/ for more info.
0016 
0017 %% define named indices into bus, gen, branch matrices
0018 [PQ, PV, REF, NONE, BUS_I, BUS_TYPE, PD, QD, GS, BS, BUS_AREA, VM, ...
0019     VA, BASE_KV, ZONE, VMAX, VMIN, LAM_P, LAM_Q, MU_VMAX, MU_VMIN] = idx_bus;
0020 [F_BUS, T_BUS, BR_R, BR_X, BR_B, RATE_A, RATE_B, ...
0021     RATE_C, TAP, SHIFT, BR_STATUS, PF, QF, PT, QT, MU_SF, MU_ST] = idx_brch;
0022 [GEN_BUS, PG, QG, QMAX, QMIN, VG, MBASE, ...
0023     GEN_STATUS, PMAX, PMIN, MU_PMAX, MU_PMIN, MU_QMAX, MU_QMIN] = idx_gen;
0024 
0025 %% generator info
0026 on = find(gen(:, GEN_STATUS) > 0);      %% which generators are on?
0027 gbus = gen(on, GEN_BUS);                %% what buses are they at?
0028 if type_initialguess == 1 % using previous value in case data
0029     % NOTE: angle is in degree in case data, but in radians in pf solver,
0030     % so conversion from degree to radians is needed here
0031     V0  = bus(:, VM) .* exp(sqrt(-1) * pi/180 * bus(:, VA)); 
0032 elseif type_initialguess == 2 % using flat start
0033     V0 = ones(size(bus, 1), 1);
0034 elseif type_initialguess == 3 % using given initial voltage
0035     V0 = V0;
0036 else
0037     fprintf('Error: unknow ''type_initialguess''.\n');
0038     pause
0039 end
0040 % set the voltages of PV bus and reference bus into the initial guess
0041 V0(gbus) = gen(on, VG) ./ abs(V0(gbus)).* V0(gbus);