Improvement of the Estimation Performance of Power System Inertia Coefficients Using B-spline Interpolation in Noisy Measurement Data Environment

The power system’s inertia coefficient is a metric that reflects the rotational inertia of the synchronous generator and measures the system’s ability to maintain frequency during disturbances. As the inertia of the power system decreases due to the expansion of renewable energy sources coupled with power electronics converters, the importance of system inertia has increased, and it becomes crucial for ensuring stable system operation. This paper introduces a method for estimating the power system inertia coefficient through the use of B-spline interpolation. B-spline interpolation method effectively captures local frequency data variations, resulting in an accurate point estimation of the inertia coefficient. Furthermore, this paper evaluates the accuracy and the precision of the proposed method by estimating the confidence interval of the inertia coefficient using the bootstrap method in statistics. Simulation results show that B-spline interpolation approach outperforms traditional polynomial fitting methods. Overall, the B-spline interpolation method provides a high level of accuracy and precision in determining the power system’s inertia coefficient.