Research On A Method For Chaos Analysis And Repression And Its Application To Ferroresonace Of Power System

The analysis and determining of non-linear system behaviour is an important scientific subject with engineering background. How to determine the behaviour and mechanism is an arduous subject. Among them, the chaos analysis and repression for high order non-linear system has been a hot spot in modern science.The ferroresonanc of the power system often presents the high order non-linear chaos behavious and produce very high inner overvoltage which will bring a big harm to the safe and stable operation of power system. So, study on analysis and repression of chaos ferroresonance of power system is of great theoretical and practical importance.For analying the chaos in high order systems and improve the methods for analytic prediction of chaos, in this paper, a new analytical method for predictiing chaos i.e the exclusion method is presented. Its basic idea is that for any systems, there are only four sorts of different solutions of steady states, they are constant solutions, periodic solutions, quasi periodic solutions and chaotic solutions. If the parameter space corresponding to the solutions except chaotic solutions is excluded, the remained parameter spaces are only the areas corresponding to chaotic solutions, and the analytical conditions for the chaotic solutions is obtained. The exclusion method has been applied to both autonomous systems and non-autonomous systems with any degrees, and the analysis process is relatively simple.This exclusion method of chaos has been applied to analyze the ferroresonance problem in power system and to solve the Van der pol-Duffing equation. The analytical conditions for the two cases are obtained, the conclusions are proved by practical examples and numerical simulation. Compared with classical Melnikov method, the new method is much more accurate and has much better adaptation for different conditions.A new method for eliminating the chaos ferroresonance is presented. Its basic idea is that if there is a normal solution for the system, and the steady state of system is unique solution, then the corresponding conditions are the conditions for elimina-ting the ferroresonance and chaos.The method has been applied to those single phase power system, neutral grounding power system and neutral non-grounding power system for eliminating chaos and ferroresonance, the corresponding conditions are obtained, and those conclusions are proved by practical examples and numerical simulation.