Grid Inertia is a measure of total kinetic energy available in the grid that balances the supply mismatch immediately after a disturbance. It plays a key role in determining the frequency dynamics and stability of the power system.
A significant amount of inertia is provided by synchronous generators such as thermal and nuclear power plants. Recently, these conventional power plants are replaced by renewable energy sources with no or less inertia resulting in reduced grid inertia. One of the main challenges in migrating towards renewable energy sources is the diminishing inertia of the power system. To tackle problems with low inertia, it is imperative to monitor inertia. Monitoring inertia will help optimize energy resources and reserves and activate controls for a secured and economic operation of the grid.
This seminar talk presents a novel method for real-time inertia estimation of a power system under ambient conditions. The inertia is computed from data provided by Phasor Measurement Units (PMUs) at the generator buses using small variations in frequency and power measurements. The method uses electrical and kinetic energy variations to compute inertia. In addition, a Q -learning-based method is presented to identify mechanical power changes to discard invalid inertia estimates. The method is demonstrated using the IEEE-39 bus system to monitor regional inertia.