A High-Precision Approach to Identify Synchronous Generator Parameters Based on Stochastic Subspace Identification
Guobin Jin · Power System Technology · 2011
The stochastic subspace identification is applied to identification of synchronous generator parameters,and a new method to process three-phase short-circuit current based on stochastic subspace identification is proposed.The stochastic subspace identification is a method to identify model parameters of linear system in time-domain,it construct Hankel matrix by output data of the system and then the system matrix and output matrix are separated from state equation of the system,thus the modal parameters,including inherent frequency,damping ratio and oscillation modes,can be identified.Analyzing short-circuit current of synchronous generator by the proposed method,firstly the time constants are identified,then the cancellation of time constants is performed in turn to identify reactance parameters.Simulation analysis on simulation signals under the condition free of damping and noise and under the background with damping and that on three-phase short circuit current of synchronous generator are carried out respectively,and based on oscillation modes the automatic ordering of the system is implemented in the calculation.Comparison of the obtained parameter identification results with those by Prony method shows that the proposed method possesses strong anti-noise performance and the identification results by the proposed method are more accurate.