Small‐signal stability analysis of Energy Internet through differential inclusion theory

Abstract

In this study, small-signal stability issue associated with uncertainty excitation is investigated by using differential inclusion theory. Specifically, a polytopic linear differential inclusion (PLDI) model for Energy Internet is developed, in which a modified non-sequence Monte Carlo method is introduced to identify a series of time-variant operation states. Additionally, a simplified small-signal model of renewable energy sources (RES) with virtual synchronous generator control is proposed, and the outputs of RES are modelled as time-varying elements in PLDI model to reflect the inner stochastic excitation in the linearised matrix. The stability criterion for the stochastic time-varying system is mathematically deduced based on convex hull Lyapunov function. Simulation demonstrates the benefits of the proposed model in describing system stochastic characteristics and reducing computational burden.