水轮机调节系统非线性建模及动力学分析

发布时间：2018-01-17 13:19

本文关键词：水轮机调节系统非线性建模及动力学分析　出处：《西北农林科技大学》2014年硕士论文　论文类型：学位论文

【摘要】：水轮机调节系统是一个多输入、多输出系统，同时包括水力、电气和机械部分，具有非最小相位调节和强非线性特点，其组成结构和控制过程都十分复杂。水轮机调节系统直接关系到水电站机组的安全稳定运行，一直是工程技术人员和科研学者关注的热点领域之一。本文系统地总结了水轮机调节系统的调节过程特点以及组成结构，将总的调节系统分为水轮机、发电机、调速器和水力系统等四个子系统并分别介绍了四个子系统各自的特点、组成以及常用的数学模型。在各子系统模型基础上，根据研究内容的侧重点分别建立了引水管道为复杂管系时的非线性水轮机调节系统模型、考虑饱和输出时存在接力器输出限幅环节的非线性水轮机调节系统模型以及考虑设置有调压室的非线性水轮机调节系统模型，同时建立了基于Matlab/Simulink的非线性水轮机调节系统仿真模型。运用非线性动力学理论知识，如Hopf分岔理论、李雅普诺夫（Lyapunov）指数判据、庞加莱（Poincare）映射等，着重分析了调速器PID参数改变时调节系统的非线性动力学行为以及参数对系统稳定性的影响。通过仿真计算得到系统的分岔图（Bifurcationdiagram）、时域图（Time Domain）、相轨迹图（Phase Trajectory）、庞加莱映射图（Poincaremap）、功率谱图（Power spectrum）和李雅普诺夫（Lyapunov）指数，并利用Simulink软件对水轮机调节系统非线性模型进行了仿真。使用直接代数Hopf分岔判据理论，可以得到水轮机调节系统调节PID参数的稳定域。判据经过坐标变换和计算，得到由系统Hopf临界分岔点所组成的曲线，由Hopf分岔临界点曲线并结合系统的时域变化图、相空间轨迹以及分岔图可以判断调节系统的运动状态和动力学发展趋势，由此获得系统PID参数的稳定域。基于Matlab/Simulink软件包建立的水轮机调节系统数学模型可实时显示系统的仿真结果，还可以随时调整系统的仿真参数，利于即时分析数据，具有操作便利、直观、快捷的特点。在水轮机调节系统的建模与仿真过程中可以结合Matlab中Simulink软件包与M文件各自特点，利用Matlab软件的M文件可求解非线性微分方程组的分岔问题，，而在研究系统时域响应时，可以使用Simulink软件包，以便更真实、快捷、准确地得到系统模型的仿真结果。本文的研究为水轮机调节系统建模与分析提供了一种方法，同时也为水电站的安全稳定运行提供了理论依据。
[Abstract]:Hydraulic turbine regulation system is a multi-input, multi-output system, including hydraulic, electrical and mechanical parts, with non-minimum phase adjustment and strong nonlinear characteristics. Its composition structure and control process are very complex, and the governing system of hydraulic turbine is directly related to the safe and stable operation of hydropower units, and has always been one of the hot areas concerned by engineers and researchers. In this paper, the characteristics of the governing process and the structure of the governing system of the turbine are summarized systematically. The total governing system is divided into the turbine and the generator. Four subsystems, such as governor and hydraulic system, are introduced respectively, their respective characteristics, composition and commonly used mathematical models. On the basis of each subsystem model. According to the emphasis of the research, the nonlinear governing system model of hydraulic turbine is established when the diversion pipeline is a complex pipe system. The nonlinear governing system model of hydraulic turbine and the governing system model of nonlinear hydraulic turbine with surge chamber are presented in this paper. At the same time, the simulation model of nonlinear turbine governing system based on Matlab/Simulink is established. The nonlinear dynamics theory is used, such as Hopf bifurcation theory, Lyapunov Lyapunov-exponent criterion, Poincare mapping and so on. The nonlinear dynamic behavior of the governing system and the influence of the parameters on the stability of the system are analyzed when the PID parameters of the governor are changed. The bifurcation diagram of the system is obtained by simulation (. ). Time domain map, phase trajectoryn, Poincaremap. Power spectrum) and Lyapunov Lyapunovo index. The nonlinear model of hydraulic turbine governing system is simulated by Simulink software. Using the direct algebraic Hopf bifurcation criterion theory, the stable region of regulating PID parameters of hydraulic turbine regulating system can be obtained. The criterion is calculated by coordinate transformation. The curve composed of Hopf critical bifurcation point of the system is obtained, and the critical point curve of Hopf bifurcation is combined with the time-domain variation diagram of the system. The phase space trajectory and bifurcation diagram can be used to judge the motion state and dynamic development trend of the regulating system, and the stability region of the PID parameters of the system can be obtained. The mathematical model of hydraulic turbine regulation system based on Matlab/Simulink software package can display the simulation results in real time and adjust the simulation parameters at any time. It is easy to analyze the data in real time and has the advantages of convenient operation, intuitive and quick operation. In the process of modeling and simulation of hydraulic turbine regulation system, the characteristics of Simulink software package and M file in Matlab can be combined. The M file of Matlab software can be used to solve the bifurcation problem of nonlinear differential equations, and the Simulink software package can be used to study the time-domain response of the system in order to be more real and fast. The simulation results of the system model are obtained accurately. The research in this paper provides a method for modeling and analysis of turbine governing system, and also provides a theoretical basis for the safe and stable operation of hydropower stations.
【学位授予单位】：西北农林科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TV734.1

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