Decentralized Stability Conditions for Inverter-Based Microgrids

We consider the problem of stability analysis of an inverter-based microgrid where higher order models are used for the inverter and line dynamics. Decentralized conditions are derived through which stability of the network can be deduced, with these formulated as input/output conditions on locally defined subsystems. The conditions derived allow to exploit the natural passivity properties of lines when these are represented in a common reference frame, but reduce the conservatism by additionally taking into account the coupling with neighbouring buses. Examples are given to demonstrate the results presented.