function deltF=func_deltF(Volt,PG,QG,PVi,PGi,wPG,wQG,wPD,wQD,wVolt,PG0,QG0,PD0,PD,QD,QD0,Volt0,Busnum,Loadi)
t3=2*wPD.*(PD(Loadi)-PD0(Loadi));
t4=2*wQD.*(QD(Loadi)-QD0(Loadi));
t5=2*wVolt.*(Volt-Volt0);
deltF=[sparse(t3);
    sparse(t4);
    sparse(t5');
    sparse(1*Busnum,1);
];

end