4Browne T J,Vittal V,Heydt G T,et al.A comparative assessment of two techniques for modal identification from power system measurements[J].IEEE Trans on Power Systems,2008,23(3):1408-1415.
5DeMello F P,Concordia C.Concept of synchronous machine stability as affected by excitation control[J].IEEE Trans on PAS,1969,88(4):316-329.