mis = V .* conj(Ybus * V) - Sbus;
F = [ real(mis([pv; pq]));
imag(mis(pq)) ];
[dSbus_dVm, dSbus_dVa] = dSbus_dV(Ybus, V);
j11 = real(dSbus_dVa([pv; pq], [pv; pq]));
j12 = real(dSbus_dVm([pv; pq], pq));
j21 = imag(dSbus_dVa(pq, [pv; pq]));
j22 = imag(dSbus_dVm(pq, pq));
J = [ j11 j12;
j21 j22; ];
dx = -(J\F); (就是这里出现错误)