The Feature Extraction of the Weak Damping Low-frequency Oscillation Mode Based on WAMS and Inverse Iteration/Rayleigh Quotient Iteration
The method for analysis on-line and control of low frequency oscillations in power system dispatch operations is based on the pattern matching,the extraction of the natural oscillation mode is the key step of the method.This paper proposes a practical method for extraction of the natural oscillation mode in interconnection power system.According to the statistics of small disturbance events with WAMS system,the system natural oscillation modes were determined,the estimate value of the oscillation modes eigenvalue is obtained through the prony analysis,it is used to be the initial transfer point of Inverse Iteration/Rayleigh Quotient Iteration.Through that the natural oscillation mode in the large-scale interconnected system is obtained,then the detailed modal analysis is taken.Finally,using actual case demonstrates the feasibility of the proposed method.