  DC microgrids are becoming popular as effective means to integrate various
renewable energy resources. Constant power loads (CPLs) may yield instability
due to the negative impedance characteristic. This paper analyzes the stability
of the DC microgrid in presence of CPL. Distributed generations (DGs) are
controlled by using a distributed controller which aims at current sharing and
voltage recovery. For simplicity, a reduced order model is derived on the
fundamental of neglecting the transient state of the DC/DC converter. The
purpose of this paper is to analyze stability conditions and give the
suggestions to design control parameters. The stability conditions are obtained
by using inertia theorem. Moreover, this paper makes a further detailed
research based on the existed theorems. Simulation results are provided to
verify the effectiveness and validity of the proposed theorem.
