Time-delayed stability criterion conservative assessment method based on Lyapunov function analysis

Abstract

The invention discloses a time-delayed stability criterion conservative assessment method based on Lyapunov function analysis, a numerical computation method is adopted to analyze a Lyapunov function, and conservative quantitative assessment is performed on time-delayed stability criterion. On the basis of a time-delayed power system mathematical model, constituent item difference of a corresponding Lyapunov function of an existing LMI time-delayed stability criterion is analyzed, system trajectory simulation and Lyapunov function normalization are performed on the difference, the derivative of the result is taken, a criterion conservative assessment index is further provided, and a time-delayed stability criterion conservative assessment method is constructed. Four existing typical time-delayed stability criterions are utilized to verify the provided method in a scene of a single-machine infinite bus time delay system. According to the invention, a Lyapunov function expression is utilized to directly analyze inherent differences of stability criterions and estimate conservatism of the criterions, and the method provides support for seeking more scientific time-delayed stability criterion.

Description

technical field [0001] The invention relates to the field of improved Euler system simulation algorithm, linear matrix inequality (LMI) technology and time-delay system stability analysis, in particular to a conservative evaluation method of LMI stability criterion of time-delay power system based on Lyapunov function analysis. Background technique [0002] With the continuous increase of the grid interconnection range, wide-area coordinated control has become an important means to ensure the safe operation of complex power systems, and has received more and more attention. In wide-area control systems, there will be significant time delays in remote measurement signals, which will adversely affect the stability and control performance of the control system, so it needs to be considered scientifically. [0003] Among various time-delay stability analysis methods, the Lyapunov stability criterion method developed based on Lyapunov stability theory and linear matrix inequality...

AI Technical Summary

Problems solved by technology

Different time-delay stability criteria will use different forms of Lyapunov functions, and different processing methods will be used in the process of determining stability derivation, resulting in large differences in the external forms of different criteria, and their conservatism and computational efficiency and numerical stability are often quite different

For the actual users of the power system, they often do not care about the specific derivation process of the Lyapunov stability criterion, but only hope to have an effective evaluation method that can help them directly analyze the internal differences of various criteria, so as to facilitate the method options, but little research has been done on this

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