Prony Method In Low Frequency Oscillation Analysis And Control Of Power System

In the environment of expanding power grid,large capacity units are also expanding their operation.The application of fast excitation is gradually widespread,and the incidence of low-frequency oscillation has increased to a certain extent.In parallel operation of generators in power grid,if disturbed,there will be relative swing between the rotors.Once there is insufficient damping,there will be persistent oscillation.Power transmission on transmission lines is also prone to oscillation.The oscillati on frequency of inertia time constant is very low,so the oscillation range is usually 0.1-2.5 Hz,that is,low frequency oscillation.This phenomenon usually occurs on long-distance and heavyload transmission lines.With the application of Euclidean transformer in high peak multiple excitation system,the frequency of low-frequency oscillation increases.Firstly,the background and methods of this research are analyzed,and the mechanism of low frequency oscillation and the research status of analysis methods are analyzed in combination with the research status at home and abroad.Based on this,the application of Prony algorithm in low frequency oscillation is discussed.The mechanism of Prony algorithm is proposed and its basic categories are discussed.On the basis of the above analysis,the Prony algorithm based on residual iteration is applied to the analysis and calculation of low frequency oscillation in Huizhou power system.On the basis of the analysis of the general situation of Huizhou power grid and the traditional calculation method in the calculation of characteristic equation coefficients,the combination of Prony algorithm and residual iteration is realized in the analysis of low frequency oscillation in Huizhou power grid,and the signals with fast attenuation component and without fast component are analyzed.The signal example of the velocity attenuation component is given,and the influence of noise and nonlinearity on Prony algorithm is discussed.The application of Prony algorithm in the identification of transfer function is discussed,which provides reference for the application of Prony algorithm in the analysis and control of low frequency oscillation of power system.In this paper,the low-frequency oscillation situation of Huizhou Jiemei Power Plant is analyzed,and the specific low-frequency oscillation problem of Jiemei Power Plant is analyzed by Prony algorithm.It is found that the application of Prony algorithm can quickly analyze the occurrence of low-frequency oscillation,which is helpful to deal with the problem in time and reduce the impact of lowfrequency oscillation.Aiming at the practical problems of low frequency oscillation in Jiemei Power Plant,the corresponding control method is put forward.The selection of controller,the basic principle of PSS and the PSS design and its application steps under Prony algorithm are analyzed in detail.After on-line identification and suppression analysis of low frequency oscillation in Jiemei Power Plant,the power system curve diagram with and without PSS design is analyzed,and PSS design is found.It can play a good role in damping the low frequency oscillation of power system,and the effect is remarkable.