【作者】 刘国平；

【导师】 徐政；

【作者基本信息】 浙江大学 ， 电力系统及其自动化， 2004， 硕士

【摘要】 本文以基于Prony法的电力系统低频振荡分析与控制为研究内容，主要做了以下工作： 1．分析了低频振荡的分类，危害，成因以及典型故障事例，比较了多种能够抑制低频振荡的措施。简介了本文工作所需要的几种工具软件—PSS/E，Matlab和SSAT。 2．通过分析特征值法存在的一些不足，引出Prony分析方法。对其基本原理，常用指标，参数选择进行了详细阐述。测试了时间长度，采样频率以及Prony模型阶数对分析结果的影响。并分析了Prony法推广到多输出信号的情况，阐明了非线性对Prony分析法的影响。最后，把Prony方法应用到了传递函数的辨识中，为后面阻尼低频振荡的控制器设计打下基础。 3．分析了阻尼低频振荡的控制器选择，主要阐明了PSS，TCSC和直流小信号调制的应用场合。在此基础上，提出了用低频振荡模态对应的留数大小来衡量控制器输入信号的有效性，用多个运行方式下留数的相对大小来衡量输入信号的鲁棒性。描述了基于Prony方法的控制器设计过程，包括PSS，TCSC和直流小信号调制。把Prony方法用于不含控制器的系统开环传递函数辨识，以及留数的求取。控制器设计主要用了极点配置的方法。并用4机系统对PSS的设计以及TCSC的控制信号选取作为例子表明了本文基于Prony方法设计低频振荡阻尼控制器的有效性。 4．采用特征值分析法详细分析了2005年夏大运行方式下南方电网的低频振荡特性，计算了对应主要振荡模式的发电机参与因子和模态分布图，并根据参与因子的大小研究了南方电网的PSS配置方案及其参数整定。采用Prony方法，研究了直流小信号调制对提高低频振荡阻尼的作用。对南方电网西电东送通道部分元件退出运行时对低频振荡特性的影响进行了研究，得出了一些重要结论。更多还原

【Abstract】 This thesis focuses on analysis and control of low-frequency electromechanical oscillations in power systems based on Prony’s method. The main work is as follows:1. Chapter 1 presents the classification, causes, and harmful subsequences of low-frequency electromechanical oscillations in power systems. Some typical accidents resulting from this kind of oscillations are presented. A comparison of deferent kind of measures to damp electromechanical oscillations is made. And an introduction to some software packages for analyzing electromechanical oscillation, including PSS/E, Matlab and SSAT, is made at the end of this chapter.2. Chapter 2 discusses the inherent drawbacks of eigenanalysis and presents Prony’s method. The principles, useful indexes and parameter selection of Prony’s method are discussed in detail. Then the tests on selection of parameters such as sampling frequency, time interval and model order are made and their impact on the result of Prony analysis is analyzed. Prony’s method is then extended to analyze multi-output signal. The impact of nonlinearity on Prony’s method is discussed as well. Prony’s method is used in transfer function identification, and it is useful for controller design for damping electromechanical oscillations.3. Chapter 3 discuses the selection of damping controllers, especially for PSS, HVDC small signal modulation and TCSC modulation. Then residues associated with the oscillation of interest are used as the effective index and their relative magnitude under several operation conditions are used as the robust index of damping controllers. The design procedure of damping controllers is presented, including PSS, HVDC small signal modulation and TCSC modulation. Prony’s method is used in open-loop transfer function identification and computation of residues. The pole-placement method is used in the design of controllers. The 4-machine system example validates the effectiveness of this Prony’s method based damping controller design.4. Chapter 4 presents a detailed analysis of low frequency inter-area oscillations of the South China Interconnected Power System for the year of 2005 based on the eigenvalue analysis method. Participation factors and mode shape diagrams of generators related to the inter-area oscillations are figured out, and locations of PSS are determined accordingly, the parameter setting for the PSS is studied as well. The method of HVDC small signal modulation is applied to enhance the small signal stability of the system; the results are investigated based on the Prony method. Theinfluences of components outage in the transmission corridor on the inter-area oscillations are further investigated, and some important conclusions are drawn.更多还原