A Survey of Global Revisions to Grid Codes on System Inertia and Frequency Stability in Power Grids with High Renewable Energy Integration

As the share of renewable energy in power systems increases, the equivalent system inertia will gradually decline, making it more difficult to maintain stable frequency during sudden changes in load or generation. This can result in challenges such as higher Rate of Change of Frequency (RoCoF), and more significant fluctuations during extreme frequency events. To address these issues, future power systems must treat the rotating mass within the grid as a critical component, ensuring a minimum level of inertia is always maintained. Additionally, alternative inertia compensators should be considered as backup solutions. This survey explores key issues related to system inertia response, inertia estimation, and frequency stability, with a focus on grid code amendments in regions with high renewable energy penetration. Specifically, it addresses grid codes concerning RoCoF characteristics and revisions to operational standards. This work provides valuable insights into future grid code requirements and development of auxiliary service market, supporting system operators in ensuring the safe and reliable operation of grids with substantial renewable energy integration.