A Faster Estimation Method for Electromechanical Oscillation Frequencies

This letter derives an analytical formula to estimate the electromechanical oscillation frequencies for multi-machine systems. The proof of the analytical formula is given via matrix determinant simplification and matrix decomposition considering line power losses. A half-size system matrix is obtained, which can speed up the computing of eigenvalues. The accuracy of the derived solution is evaluated by comparing with the PSAT toolbox on the eastern and western interconnection systems, respectively, under different operating conditions. Results highlight the accuracy and acceleration effect of the proposed method.