Online Inertia Estimation of Power Systems Based on Transient Phasor Data with Weighted Least Squares Method

Due to the continuous progress of carbon neutrality, power generation based on synchronous generators with physical inertia will be gradually withdrawn from the grid, which leads to low inertia of the power system. In order to grasp and cope with this risk, an accurate estimation of power system inertia is needed. In this paper, we propose an estimation method based on transient data, which is built on our previous research and establishes a simple optimization problem that is based on the definition of the swing equation. Different from the previous studies, the weighted least squares method is utilized to solve the problem instead of the traditional least squares method. Also, several different weight determination methods are tested, including one that has been determined to be valid in a different inertia estimation method. Simulations of three representative scenarios are performed in the IEEE New England 10 Machine Test System. The results demonstrate the progressiveness of the proposed method and identify the optimal weight calculation method.