【作者】 孙丽颖；

【导师】 赵军；

【作者基本信息】 东北大学 ， 控制理论与控制工程， 2009， 博士

【摘要】 电力系统是一个强非线性、多维、动态大系统。随着电力工业的迅速发展,电力系统单机容量不断地增加,电网结构日益复杂和庞大,使得稳定性问题极为突出。因而,设计先进的控制系统,在提高电网传输能力的同时保证足够的稳定裕度成为电力系统的重要研究课题之一。本文针对电力系统的非线性模型,基于backstepping方法,研究了电力系统励磁、汽门以及各种FACTS控制等一系列稳定控制问题。具体工作归纳如下:第一章简要地介绍了电力系统的主要控制对象和基本的控制问题、电力系统稳定及其进展、非线性控制方法及在电力系统中的应用现状以及本文的主要工作。第二章,研究了含有内部参数不确定性及外部扰动的TCSC单机无穷大系统的鲁棒H_∞控制问题。应用自适应backstepping方法和Lyapunov方法,构造出系统的存储函数,同时设计了H_∞控制器及参数替换律,保证了电力系统的稳定性。第三章,提出了一种改进的自适应backstepping方法,并应用于FACTS的鲁棒控制问题中。由于控制器的递推设计过程中引入了κ类函数,改善了电力系统的暂态性能,长期来看又不会增加控制器增益。第四章在第三章的基础上,将改进自适应backstepping方法与滑模控制方法相结合,汲取了滑模控制鲁棒性强的优点。研究了具有内部参数不确定及外部扰动的单机无穷大电力系统的暂态稳定性问题。第五章提出了一种新的自适应backstepping方法,避免了传统自适应backstepping方法由于反复的微分运算而产生的系数膨胀问题,同时也不必为每个子系统构造Lyapunov函数,使得设计过程更加简单。应用该方法设计了发电机主汽门非线性鲁棒控制器。第六章应用协调无源性方法研究了具有发电机励磁和TCSC协调控制的单机无穷大系统的暂态稳定性问题。在控制器的设计过程中,同时考虑了发电机阻尼系数不易精确测量和TCSC含有未建模动态两种类型的不确定性。第七章,研究了考虑输入控制量幅值约束的汽轮机调速系统的暂态稳定性问题。通过引入切换机制,解决了输入控制量幅值约束问题。论文的第八章是结论与对下一步研究工作的展望。更多还原

【Abstract】 Power systems are strongly nonlinear, multidimensional, dynamic and large scale systems. With the rapid development of power industry, as well as the big leap in single unit capacity, the power network structure has witnessed a rapid increase in the size and complexity. Maintaining power system stability is thus one of the main concerns. The design of an advanced control system to enhance the power system stability margin so as to achieve higher transfer limits is one of the major problems in the study of power systems.In this dissertation, aiming at the nonlinear model of power systems and based on the backstepping methods, a series of stability control problems are studied, including excitation control, steam-valve control, and main FACTS devices control, etc. The main contributions are as follows.Chapter 1 firstly gives a brief review of power systems on the main control objects and the basic control problems. Then the stability of power systems and its new results are introduced, respectively. After that, the nonlinear control methods and their recent applications in power systems are introduced. Finally, the main work of this dissertation is sum up.In chapter 2, for a single machine-infinite bus system with thyristor controlled series compensation (TCSC) with internal parameter uncertainties and external disturbances, the robust H_∞control problem is addressed. Storage functions of control system are constructed based on adaptive backstepping and Lyapunov methods, then a robust H_∞controller and a parameter updating law are obtained simultaneously to ensure the transient stability of single-machine infinite-bus system with TCSC.In chapter 3, the robust control problem for FACTS is addressed via the proposed modified adaptive backstepping method. In the recursive design procedure of the feedback control law, the class-κfunctions are introduced to improve the transient response of the closed-loop system without exploiting a large controller gain in a long term.Based on chapter 3, chapter 4 combines the methods of both modified adaptive backstepping and sliding mode control in order to use the advantages of strong robustness of sliding mode control. The transient stability problem is studied for a single machine-infinite bus system with internal parameter uncertainties and external disturbances.Chapter 5 proposes a novel adaptive backstepping method which avoids the explosion of computation caused by repeated differentiation. At the same time, it is not necessary to construct Lyapunov function candidate for each subsystem at each backstepping step. Thus, the design procedure of the controller is much simplified. A nonlinear steam valve controller is designed by using the proposed method.Chapter 6 investigates the transient stability problems of a single machine infinite bus system with the generator excitation and TCSC, via coordinated passivation techniques. Two types of uncertainties, namely, the damping coefficient uncertainty and the modeling error of TCSC, are considered in the design procedure of the controller.In chapter 7, for the turbine speed governor system with input constraints, the transient stability problem is addressed. The problem of the control input constraints is solved via introducing the switching mechanism.Concluding remarks are presented at the end of this dissertation. Some interesting problems are also pointed out, which deserve further study.更多还原