电力系统低频振荡非线性机理及控制策略研究

发布时间：2018-06-13 09:14

本文选题：电力系统 + 低频振荡　；参考：《华北电力大学》2015年硕士论文

【摘要】：电网安全稳定供电是保证国家经济稳步增长的必要条件,然而随着电网规模的扩大和工作环境的逐渐恶化,互联电网间的摇摆振荡为电力系统带来更严峻的考验。其中,电力系统低频振荡是常见振荡类型之一,为抑制和控制低频振荡,探明其产生机理是一项重要研究内容。作为典型多变量非线性动态系统,电力系统具有复杂的非线性动力学行为,系统自身的非线性物理特性是低频振荡的重要诱因之一。本文研究重点就是将混沌理论运用于电力系统,通过理论分析和模拟仿真,探索诱发电力系统低频振荡的非线性机理、分析系统混沌时的低频振荡特性并利用混沌控制方法实现电力系统低频振荡控制。论文首先从分岔和混沌角度综述了低频振荡非线性机理相关的研究成果。在探讨不同维数系统的建模方法后,以单机无穷大系统为代表,采用四阶龙格-库塔法为描述系统动态过程的微分方程求得数值解,得到系统功角的最大Lyapunov指数谱及分岔图以揭示扰动功率强度及阻尼参数对混沌特性的影响,并对典型分岔参数取值下系统的时序图、相图进行分析,展现非线性系统分岔、混沌进程中与电力系统低频振荡对应的单模式、多模式、失稳等现象。将常用的两种低频振荡分析方法——滑窗FFT法和Prony法用于混沌状态下系统振荡频率、振荡幅值、衰减系数等低频振荡特性值的求解。在充分掌握系统特性之后,利用不同控制方法分别对二维和四维混沌系统进行控制,以此抑制混沌导致的低频振荡,仿真分析证明本文所设计控制器能够消除电力系统混沌进而抑制低频振荡,将系统控制到稳定状态。
[Abstract]:The safe and stable power supply is a necessary condition to ensure the steady growth of national economy. However, with the expansion of the scale of the power network and the deterioration of the working environment, the swing oscillation between the interconnected power grids brings a more severe test to the power system. The low frequency oscillation of power system is one of the common oscillation types. In order to suppress and control the low frequency oscillation, it is an important research content to find out the mechanism of the low frequency oscillation. As a typical multivariable nonlinear dynamic system, power system has complex nonlinear dynamic behavior. The nonlinear physical characteristics of the system itself is one of the important inducements of low frequency oscillation. The key point of this paper is to apply chaos theory to power system. Through theoretical analysis and simulation, the nonlinear mechanism of inducing low frequency oscillation in power system is explored. The characteristic of low frequency oscillation in chaotic system is analyzed and the low frequency oscillation control of power system is realized by means of chaos control method. In this paper, the research results of nonlinear mechanism of low frequency oscillation are summarized from bifurcation and chaos. After discussing the modeling methods of different dimensional systems, the numerical solution is obtained by using the fourth order Runge-Kutta method as the differential equation to describe the dynamic process of the system, taking the single-machine infinite bus system as the representative. The maximum Lyapunov exponent spectrum and bifurcation diagram of the power angle of the system are obtained to reveal the influence of the disturbance power intensity and damping parameters on the chaotic characteristics. The timing diagram and phase diagram of the system are analyzed under the typical bifurcation parameters to show the bifurcation of the nonlinear system. Single mode, multi-mode, instability and other phenomena corresponding to low frequency oscillation in power system in chaotic process. Two common low-frequency oscillation analysis methods, the sliding window FFT method and the Prony method, are used to solve the low frequency oscillation characteristic values such as the oscillation frequency, the oscillation amplitude and the attenuation coefficient. After fully grasping the characteristics of the system, the two-dimensional and four-dimensional chaotic systems are controlled by different control methods to suppress the low frequency oscillation caused by chaos. The simulation results show that the controller designed in this paper can eliminate the chaos of the power system and suppress the low frequency oscillation, which can control the system to a stable state.
【学位授予单位】：华北电力大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TM712

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