The stability of a DC power distribution system is a key design aspect. The presence of constant-power load induces negative impedance instabilities which should be considered during system design. In this paper the problem of DC power system stability is addressed and two solutions are proposed and compared. The former exploits the insertion of a suitably sized capacitor in parallel to the constant-power converter, while the latter makes use of a storage system controlled through a PI regulator. Simulation results are reported to verify the analysis