Evaluation of Inertia Distribution in Power Systems Based on Regional Inertial Centers

Plenty of frequency measurement points are needed in traditional inertia evaluation methods to evaluate the inertia distribution in large systems. In this paper, an inertia evaluation method based on regional inertial center is proposed, which is able to obtain the inertia distribution and total inertia of the system by using the frequency measurement of each regional inertial center. Firstly, the cluster partitioning algorithm is used to divide the generator into different regions, and based on the linear relationship between node frequency and generator frequency, the nodes are divided to the most closely related generators. Secondly, the inertial center of each region is identified according to the electrical distance. Then, disturbances are applied to different regions, and the inertia of each region is estimated by measuring the frequency change of the inertial center of the region, based on which the total inertia of the system is obtained. Finally, it was verified in the two-area four-generator system that the proposed inertia evaluation method can achieve accurate estimation of inertia distribution with limited frequency sampling point.