水轮机调速器超低频振荡仿真及其控制器的研究

发布时间：2018-06-26 11:45

本文选题：超低频振荡 + 小干扰稳定分析　；参考：《西南交通大学》2017年硕士论文

【摘要】：随着水轮机调速系统的不断发展,调速系统对电网低频振荡的影响越来越引起人们的关注。通过理论分析发现,调速系统不仅会影响电网低频振荡阻尼特性,还会向电网注入比低频振荡频率更低的超低频振荡模态,它经常在调速系统动作时出现,严重威胁着电网安全稳定运行。在实际系统中水轮机调速器的控制参数,通常是通过阶跃响应、冲激响应等实验手段,并结合曲线拟合等方法求得的,建模参数往往存在一些误差,因此其参数存在不确定性。另一方面,水轮机调速系统是典型的非最小相位系统,因此本论文中采用线性矩阵不等式方法设计鲁棒控制器。本文中,主要对水轮机调速系统超低频振荡仿真分析和其控制器的设计进行了研究。论文中,对小干扰稳定性分析理论进行简单阐述,主要介绍了小干扰稳定分析的理论、方法以及步骤,分别对单机无穷大系统和多机系统进行了分析,并且搭建了电力系统主要组成子模块的数学模型。以7型水轮机调速系统为算例,通过转矩分析理论,详细分析了水轮机调速系统在系统发生低频振荡时对电力系统阻尼特性的影响,并在Matlab/Simulink软件中,分别对7型水轮机调速系统、6型水轮机调速系统以及PID型水轮机调速系统进行仿真验证,并对仿真结果进行分析比较。通过对仿真结果分析,还验证了电力系统发生超低频振荡是由于多台机组调速器参数的不合理(改变),并且它们之间相互作用,使得系统阻尼比严重下降而引起的,而仅仅一台机调速器参数的改变并不能使系统发生超低频振荡。阐述了线性矩阵不等式的理论基础及相关引理,针对典型的非最小相位系统水轮机调速系统设计鲁棒控制器,增加系统的阻尼比,使系统的稳定性能得以改善,同时系统拥有良好的动态特性以及鲁棒性能。
[Abstract]:With the development of hydraulic turbine speed regulation system, people pay more and more attention to the influence of speed regulation system on power grid low frequency oscillation. Through theoretical analysis, it is found that the speed regulation system will not only affect the damping characteristics of the low frequency oscillation of the power grid, but also inject the ultra-low frequency oscillation mode lower than the low frequency oscillation frequency into the power network. It is a serious threat to the safe and stable operation of power grid. In the practical system, the control parameters of hydraulic turbine governor are usually obtained by experimental means such as step response, impulse response and curve fitting. The modeling parameters often have some errors, so the parameters are uncertain. On the other hand, the hydraulic turbine speed regulation system is a typical non-minimum phase system, so the linear matrix inequality (LMI) method is used to design the robust controller in this paper. In this paper, the simulation analysis of ultra-low frequency oscillation and the design of its controller are studied. In this paper, the theory of small disturbance stability analysis is briefly expounded, the theory, method and steps of small disturbance stability analysis are introduced, and the single machine infinite bus system and multi machine system are analyzed respectively. The mathematical model of the main sub-modules of the power system is also built. Taking model 7 hydraulic turbine governing system as an example, through torque analysis theory, the influence of hydraulic turbine speed regulation system on the damping characteristics of power system when the low frequency oscillation occurs in the system is analyzed in detail, and in Matlab / Simulink software, The model 7 hydraulic turbine speed regulation system and the pid turbine speed governing system are simulated and verified, and the simulation results are analyzed and compared. Through the analysis of the simulation results, it is also proved that the ultra-low frequency oscillation in power system is caused by the unreasonable (changing) of the governor parameters of several units, and the interaction between them causes the system damping ratio to decrease seriously. But the change of the parameters of a single governor can not make the system very low frequency oscillation. The theoretical basis and related Lemma of linear matrix inequality (LMI) are described. A robust controller is designed for typical non-minimum phase hydraulic turbine governing system, which increases the damping ratio of the system and improves the stability of the system. At the same time, the system has good dynamic characteristics and robust performance.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM712

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