  The power flow is a non-linear problem that requires a Newton's method to be
solved in dc microgrids with constant power terminals. This paper presents
sufficient conditions for the quadratic convergence of the Newton's method in
this type of grids. The classic Newton method as well as an approximated Newton
Method are analyzed in both master-slave and island operation with droop
controls. Requirements for the convergence as well as for the existence and
uniqueness of the solution starting from voltages close to 1pu are presented.
Computational results complement this theoretical analysis.
