engleski

On-Line Synchronous Generator Stability Limit Determination

This paper presents the method for on-line determining the dynamic stability limit of a synchronous generator connected to power system. Presented method is implemented in digital control system and a series of experiments have been carried out on a synchronous generator. In order to determine damping of electromechanical oscillation the following methodology was applied. In real time a third order system matrix is identified from the measurements. The algorithm for identifying the system matrix is a recursive last squares algorithm in real time. For the current operating point from system matrix are determined eigenvalues, the damping coefficient and oscillations frequency. The character of electromechanical oscillations changes when the operating point of the synchronous generator is changed. With that the system's eigenvalues change as well, leading to a change in the damping coefficient of electromechanical oscillations. In the synchronous generator capacitive operating area, with the electromechanical oscillations mode dominant, the dynamic stability limit will be characterized by the occurrence of undamped electromechanical oscillations, i.e Hopf bifurcation. The proposed method is intended for implementation in excitation systems of synchronous generators in power plants so as to determine the dynamic stability of the synchronous generator in real time.

Synchronous Generator; Dynamic Stability; Stability Limit

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