Modal Estimation of Low-frequency Oscillation Using Perturbation Sensitivity Matrix with Multiple Parameters

Abstract

A method based on multi-parameter second-order perturbation sensitivity is proposed to estimate the low-frequency oscillation modals in a power system, since the changing low-frequency oscillation modal is hard to estimate due to the variety of multiple parameters. First, the multi-parameter second-order perturbation sensitivity matrices of eigenvalues and eigenvectors are deduced, respectively. Second, second-order estimated values based on second-order perturbation sensitivity are deduced. On this basis, the changing oscillation modals under multiple parameters variation are then estimated. The simulation results of 4-generator, 16-generator, and China Southern Grid systems demonstrate that this method is not only able to estimate the oscillation modes but also the modals of the system with more accuracy in the case of multiple parameters of the system that change simultaneously. Then it can adjust an appropriate dispatching method accordingly to improve the damping of the dominant oscillation mode. Also, this method makes the solving process direct and explicit since it avoids the burdensome derivation calculation of second-order sensitivity, and it saves time by avoiding solving complicated high-dimensional state equations.