Frequency control of droop‐based low‐voltage microgrids with cobweb network topologies

Abstract

When distributed generation (DG) technologies are implemented in an islanded low-voltage microgrid (LVMG), the topological architecture directly affects the frequency synchronisability. Especially in cases of high DG penetration, the synchronisability of existing traditional topological architectures for LVMGs is very limited. However, a cobweb network topology, which combines the characteristics of several traditional topological architectures, has become a novel alternative for LVMGs. In this context, a compact criterion related to the Moore–Penrose inverse of the incidence matrix for the synchronisability of an LVMG is derived. Then, based on a linear transformation and Moore–Penrose inverse theory, a comparative analysis of the synchronisability of LVMG systems with different topological architectures is presented, the results of which indicate that the synchronisability can be significantly enhanced in a cobweb network topology and that the Braess paradox can also be effectively avoided during the corresponding topological transformation. The effectiveness of the proposed synchronisation criterion is validated based on the Iceland power network, modelled as a cobweb-based LVMG with large-scale DG integration, which exhibits excellent sychronisability.