function?[load_shed?EXIT]?=?load_shedding（mpc）
%該函數根據輸入的系統數據mpc，計算得到各節點切負荷情況
%mpc：系統數據，其中包括線路、發電機狀態
%load_shed：兩列的矩陣，第一列為節點編號，第二列為對應切負荷量，單位MW
%EXIT：優化算法收斂標志，如果為1則表明找到最優解

[PQ?PV?REF?NONE?BUS_I?~?PD?QD?GS?BS?BUS_AREA?VM?...
????VA?base_KV?ZONE?VMAX?VMIN?LAM_P?LAM_Q?MU_VMAX?MU_VMIN]?=?idx_bus;
[F_BUS?T_BUS?BR_R?BR_X?BR_B?RATE_A?RATE_B?...
????RATE_C?TAP?SHIFT?BR_STATUS?PF?QF?PT?QT?MU_SF?MU_ST?...
????ANGMIN?ANGMAX?MU_ANGMIN?MU_ANGMAX]?=?idx_brch;
[GEN_BUS?PG?QG?QMAX?QMIN?VG?Mbase?GEN_STATUS?PMAX?PMIN?...
????MU_PMAX?MU_PMIN?MU_QMAX?MU_QMIN?~?PC2?QC1MIN?QC1MAX?...
????QC2MIN?QC2MAX?RAMP_AGC?RAMP_10?RAMP_30?RAMP_Q?APF]?=?idx_gen;



%%?形成節點、線路、發電機參數，定義基準功率
bus?=?mpc.bus;
gen?=?mpc.gen;
branch?=?mpc.branch;
baseMVA?=?mpc.baseMVA;
%修改線路，去掉停運線路
index?=?find（branch（:?BR_STATUS）?==?0）;
branch（index?:）?=?[];
%節點數和當前支路數
Nb?=?size（bus?1）;
Nl?=?size（branch?1）;

%%?形成B0導納矩陣
stat?=?branch（:?BR_STATUS）;????????????????????%%?ones?at?in-service?branches支路狀態
b?=?stat?./?branch（:?BR_X）;????????????????????%%?series?susceptance電納
tap?=?ones（Nl?1）;??????????????????????????????%%?default?tap?ratio?=?1
i?=?find（branch（:?TAP））;???????????????????????%%?indices?of?non-zero?tap?ratios?（TAP=RATIO）ratio~=0的序號
tap（i）?=?branch（i?TAP）;????????????????????????%%?assign?non-zero?tap?ratios
b?=?b?./?tap;
%構建支路節點關聯矩陣
f?=?branch（:?F_BUS）;???????????????????????????%%?list?of?“from“?buses
t?=?branch（:?T_BUS）;???????