  The proliferation of inverter-based generation and advanced sensing,
controls, and communication infrastructure have facilitated the accelerated
deployment of microgrids. A coordinated network of microgrids can maintain
reliable power delivery to critical facilities during extreme events. Low
inertia offered by the power electronics interfaced energy resources however,
can present significant challenges to ensuring stable operation of the
microgrids. In this work, distributed small-signal stability conditions for
inverter-based microgrids are developed that involve the droop controller
parameters and the network parameters such as line impedances, loads, etc. The
distributed closed-form parametric stability conditions derived in this paper
can be verified in a computationally efficient manner, facilitating the
reliable design and operations of networks of microgrids. Dynamic phasor models
have been used to capture the effects of electromagnetic transients. Numerical
results are presented, along with PSCAD simulations, to validate the analytical
stability conditions. Effects of design choices, such as the conductor types,
and inverter sizes, on the small-signal stability of inverter-based microgrids
are investigated to identify interpretable stable or unstable region estimates.
