Estimating inertia distribution to enhance power system dynamics

The understanding of power system characteristics and their impact on system behavior can lead to improved dynamic performances. Based on the Center of Inertia (COI) concept, this paper presents a practical study on the inertia distribution estimation, which can be used to both planning in long time scale and operation in short time scale, to meet with increasing renewable integration level in the future power system. Two indices are created to calculate the inertia distribution over the grid. Specifically, it is found that the proposed indices are highly related to the grid structure, and also they are affected by different parameters such as inertia constant, line parameters, terminal voltage set point of synchronous machines and models of exciters and governors. With these characteristics, the proposed indices have the potential to be applied on problems such as the placement of phasor measurement units or energy storage systems and generators coherency detection. Simulation results in a radial system, a meshed system and the IEEE 39-bus test system verify the characteristic of the proposed indices and show their potential applications in modern power systems.