The admissible set of parameters guaranteeing small‐signal stability of a microgrid

Abstract

Abstract Microgrids possess rotating generators and inverter‐based renewable resources and have limited inertia. The stability of a microgrid is affected by the parameters of controller and system equipment. This paper analyzes the set of all admissible parameters that guarantee the small‐signal stability of a multi‐source microgrid, which is called the small‐signal stability region (SSSR). First, the stability impact of parameters varying in a given hypercube is studied. A sufficient robust stability condition is proposed with a hypercube parameter set, giving rise to linear matrix inequalities. The maximal hypercube ensuring stability can be found via dichotomy. Then, the SSSR is constructed via the union of hypercubes centered at different points. A special partitioning‐and‐pruning algorithm is proposed to search the parameter space and reduce the number of hypercube regions. Case studies are conducted on a testing system with a micro‐turbine generator and two inverter‐based generators. The SSSR is visualized, illustrating the interaction among generators and the stability impact of loads. The proposed method provides a useful reference for system design and security assessment.