An Improved Inertia Measurement Method Based on EMD Decomposition

With the introduction of dual-carbon goals, large-scale renewable energy units have been connected to the power system via power electronic devices, which leads to a reduction and uneven distribution of system inertia. According to reference [1] and reference [2], the conventional concept of average inertia fails to accurately reflect the inertia levels within specific regions. Therefore, online inertia measurements at different locations of the system becomes important. Due to the interaction of synchronous machines in the power system, low-frequency oscillations pose challenges to the accuracy of inertia measurements. To tackle this issue, this paper uses the empirical mode decomposition (EMD) method to eliminate the side effect of the low-frequency oscillation components in the frequency response curve and employs the second-order rotor swing equation of the generator to achieve precise measurement of inertia. Finally, the IEEE three-machine nine-node model is used to verify the correctness of the algorithm.