The estimation of inertia and load damping constants using phasor measurement data

Two very important parameters especially in frequency stability analysis, are inertia constant and equivalent load damping constant of system. Equivalent inertia constant depends on inertia constant of synchronous machines in the grid and load damping factor depends on frequency sensitivity of load, especially induction motors. By appearing wide area monitoring systems (WAMS) based on phasor measurement units, equivalent system frequency response can be obtained with high accuracy. In this paper firstly, the equivalent frequency response is achieved by phasor measurements and then according to the transient and steady state characteristics of the frequency response, the inertia and load damping constants are estimated. The performance of proposed method in estimating the equivalent parameters of the system is investigated under different conditions. The developed method is implemented in IEEE 39-Bus dynamic test grid.