Abstract

As renewable resources gradually replace conventional generation based synchronous machines, the dynamics of the modern grid changes significantly and the system synchronous inertia decreases substantially. This transformation poses severe challenges for power system stability; for instance, it may lead to larger initial rate of change of frequency and increase frequency excursions. However, new opportunities also arise as novel converter control techniques, so-called grid-forming strategies, show higher efficiency and faster response than conventional synchronous generators. They mainly involve virtual inertia (VI) emulation to mimic the behavior of synchronous machines. In this study, a state-space model for the power system network is developed with VI as a frequency regulation method. A reduced model based H2-norm algorithm (RMHA) considering the Fiedler mode impact is proposed in this paper to optimize the allocation of VI devices and improve power system frequency stability. Finally, mcase studies conducted on the IEEE 24-bus system demonstrate the efficacy of the proposed RMHA approach.

Index Terms

Frequency stability, Grid-forming converter, H2-norm, Low inertia power systems, Optimal virtual inertia allocation, Virtual inertia.

Cite this paper:

Mingjian Tuo and Xingpeng Li, “Optimal Allocation of Virtual Inertia Devices for Enhancing Frequency Stability in Low-Inertia Power Systems”, 53rd North American Power Symposium, College Station, TX, USA, Nov. 2021.