Validating Inertia Assessment Metrics in Distribution Systems with High RES Penetration

The role of inertia in distribution networks is rapidly increasing. Many researchers are focused on ways to estimate, measure, and control inertia, as it has become a crucial parameter that provides valuable information for network management. However, the distribution network is not as stable and has many more nodes compared to the transmission network. Additionally, the distribution network is populated with various renewable energy sources. While this brings several advantages, such as reducing fossil fuel-based energy production and adjusting voltage in remote nodes of the network, it also significantly impacts the network's inertia due to the removal of rotating electrical assets in favor of renewable sources. To address this issue, the paper tests a new inertia metric on a section of a real network with significant presence of renewables. This metric, calculated using frequency and power measurements, demonstrates a strong capability to reflect the current state of inertia in the network. The paper concludes with a description of the network under consideration, the instrumentation used, and a brief uncertainty analysis.