A case study on the integration of a 100 MW BESS into a 220 kV Australian grid using conventional Protection and Control schemes

The integration of BESS into modern power grids is becoming increasingly common as part of efforts to enhance grid stability, accommodate intermittent renewable generation, and provide ancillary services. Its ability to store excess energy during the day (from solar or wind) and discharge it when needed helps flatten demand curves and reduces reliance on fossil-fuel plants during peak demand. While these systems offer numerous benefits, including frequency regulation and peak shaving, they introduce unique challenges for traditional protection schemes due to their distinct current profiles, absence of rotational inertia, and complex interaction with the existing grid infrastructure.

This paper examines the integration of a 100 MW BESS into a 220 kV Australian grid and the hurdles encountered when configuring protection and control systems for such a setup.

Specifically, the study focuses on the difficulties in setting protection relays due to the low fault current contribution of the BESS and the challenges faced in tuning backup protection schemes originally designed for higher fault levels. It also examines the application and performance of conventional protection and control schemes, specifically directional overcurrent protection, hardwired inter‑trip signalling, and negative‑sequence current detection in the context of inverter‑based fault behaviour. Fault ride through settings in response to the voltage and frequency disturbances have also been discussed.

By analysing protection coordination studies, inverter fault‑current characteristics, and interface logic between the BESS and the transmission network, the case study evaluates the extent to which conventional protection methods can be adapted to reliably accommodate BESS technology.