Grid Forming Inverters to Strengthen Frequency Stability of a Very Low Inertia System: A State of the Art

Abstract

replicate the behaviour of the synchronous machine via different control strategies. Additionally, they can contribute to grid stability by providing voltage and frequency support. This paper includes a systematic review of recent advancements in gridforming converters with BESS (GFM BESS), its modelling and different control techniques to enhance the frequency stability of large-scale power system networks. Inertia in the power system is the energy stored in a large rotation part of a conventional synchronous generator which helps during any contingency like load imbalance or generator outage. The inertia of rotating parts under such conditions will help to stabilize the frequency. With an increasing share of IBRs, the lack of inertia by grid-forming converters is provided with a pulse width modulation controller linked with conventional inverters. This concept of virtual inertia by emulating the behaviour of GFM as a synchronous generator has been discussed with different virtual inertia-based control techniques with their comparative study. Also, challenges and open issues related to the high penetration of GFM BESS and the transition from islanded to a grid-connected mode of grid-forming converters are discussed.