  In this two-part paper we develop a unifying framework for the analysis of
the feasibility of the power flow equations for DC power grids with
constant-power loads.
  Part II of this paper explores further implications of the results in Part I.
In particular, we refine several results in Part I to obtain a necessary and
sufficient condition for the feasibility of nonnegative power demands, which is
cheaper to compute than the necessary and sufficient LMI condition in Part I.
Moreover, we prove two novel sufficient conditions, which generalize known
sufficient conditions for power flow feasibility in the literature. In
addition, we prove that the unique long-term voltage semi-stable operating
point associated to a feasible vector of power demands is a strict high-voltage
solution. A parametrization of such operating points, which is dual to the
parametrization in Part I, is also obtained, along with a parametrization of
the boundary of the set of feasible power demands.
