UPFC抑制电力系统强迫振荡研究

论文总字数：44168字

摘 要

随着电力系统的不断发展，大电网互联、区域互联已成为趋势，电网结构日益壮大，但是也增加了系统中出现强迫振荡、负阻尼振荡等低频振荡的可能性，给电网安全稳定运行带来了安全隐患。本文在研究分析了电力系统强迫振荡产生机理和振荡特征的基础上，采用统一潮流控制器及其附加阻尼控制器，针对电力系统强迫振荡的抑制问题，展开了相关研究。

本文首先研究并分析了周期性波动的扰动源引起强迫振荡的原因、机理、作用过程和响应结果，并在此基础上导出了强迫振荡响应的幅值与扰动源幅值、扰动源频率及系统阻尼比之间的关系式。分析结果表明，强迫振荡扰动源在系统中引发的稳态强迫振荡振幅与扰动源振幅成正比，且扰动源频率越接近系统固有频率，系统固有频率对应的振荡模式阻尼比越低，强迫振荡振幅越大。该结论为进一步研究抑制强迫振荡的策略提供了参考和导向。

其次，本文在PSASP仿真平台上建立了统一潮流控制器的动态控制模型，研究了统一潮流控制器及其附加阻尼控制器抑制系统强迫振荡的能力，并在此基础上提出一种利用统一潮流控制器及其附加阻尼控制器抑制系统强迫振荡的控制策略，设计了针对强迫振荡的控制器。该策略以降低区域间振荡能量为目标，从而降低系统强迫振荡的功率幅值，起到抑制系统强迫振荡的作用。仿真算例表明，该策略能有效抑制强迫振荡。

最后，本文考虑到实际情况中系统可能存在多种扰动源，如强迫振荡扰动源、负阻尼机理扰动源及二者叠加的多类型扰动源。因此针对强迫振荡和负阻尼振荡的产生机理和抑制方法，设计了一个基于PSO算法的协调优化策略，使控制器能在降低系统强迫振荡能量和提高系统对应振荡模式阻尼比之间尽量达到平衡。仿真算例表明，该策略不仅能改进强迫振荡抑制效果，也能显著提高系统振荡模式的阻尼比，从而有效改善系统对多类型扰动源引发的低频振荡的抑制效果。

关键词： 强迫振荡，UPFC，附加阻尼控制器，PSO算法，协调优化

Design of UPFC Controller to Damp Forced Oscillation in the Power System

Student Name: Chen Qiong Student Number: 16012133 Supervisor: Jiang Ping

Abstract

With the continuous development of power system, power grid interconnection and regional interconnection has become a trend. Power grid structure is growing, but it also increases the possibility of arising forced oscillation and negative damped oscillation in the system, which brings hidden danger to the power grid’s security. Based on the research and analysis of mechanism and vibration characteristics of the forced oscillation in power system, this paper uses the unified power flow controller(UPFC) and the additional damping controller to carry out the related research, in order to damp the forced oscillation of power system,.

At first, this paper studies and analyses reasons, mechanism, processes and the result of the response of the forced oscillation, caused by the periodic disturbance sources. On the basis of the conclusion, this paper export the relation between the amplitude of the forced oscillation response with the amplitude and frequency of the disturbance source, and the system damping ratio. The analysis results show that the amplitude of the forced oscillation caused by forced oscillation disturbance sources in the system is proportional to the amplitude of the source of disturbance. Besides, the closer the system natural frequency and the disturbance source frequency, or the greater the oscillation amplitude, or the lower the oscillation mode damping ratio, the greater the oscillation amplitude will be. The conclusion provides reference and guidance for the further study of forced oscillation strategy.

Secondly, this paper established a dynamic control model of the unified power flow controller in PSASP simulation platform. Besides, this paper studies the control capability of UPFC and the additional damping controller to damp the forced oscillation. Otherwise, this paper advances a kind of control strategy to suppress the forced oscillation by using UPFC and its additional damping controller. The strategy takes reducing the oscillation energy as the goal, in order to reduce the amplitude of the forced oscillation, which has the effect of suppressing the forced oscillation. The simulation examples show that the strategy can inhibit forced oscillation to a lower level effectively.

Finally, considering the actual situation, the system could be affected by a variety of disturbance source, such as forced oscillation disturbance source, negative damping mechanism disturbance source and the superposition of the two kinds of disturbance source. So this paper designs the coordination optimization objectives and constraint function to suppress the negative damping oscillation. Besides, this paper uses the PSO optimization algorithm to optimize the relation, which makes the controller can get an optimal balance between reducing the forced oscillation energy and improving the system damping ratios in a larger frequency range. The simulation examples show that this strategy can not only improve the suppression of the forced oscillation, but also can significantly increase the damping ratio of system, which improving to suppress the low frequency oscillation caused by the multi-type disturbance sources effectively.

Key words: Forced Oscillation, UPFC, Additional Damping Controller, PSO, Coordination Optimization

目录

第一章 绪论 1

1.1 研究背景和意义 1

1.2 统一潮流控制器（UPFC）研究现状 2

1.2.1 UPFC的数学模型 2

1.2.2 UPFC在电力系统控制中的应用 2

1.2.3 UPFC的控制策略 3

1.3 电力系统强迫振荡的研究现状 3

1.3.1强迫振荡机理分析 3

1.3.2强迫振荡的定位与辨识 4

1.4 本文主要研究内容 4

第二章 强迫振荡机理研究与特性分析 6

2.1 强迫振荡概述 6

2.2 强迫振荡分析方法 6

2.2.1 单机无穷大系统分析 6

2.2.2 多机系统分析 9

2.3强迫振荡响应特点分析 11

2.4 本章小结 12

第三章 基于附加阻尼控制器的UPFC抑制强迫振荡策略 14

3.1 UPFC工作原理与仿真模型建立 14

3.1.1 UPFC工作原理 14

3.1.2 UPFC等效功率注入仿真模型 15

3.2 基于附加阻尼控制器的UPFC强迫振荡抑制策略 17

3.2.1 UPFC抑制区域间强迫振荡原理 17

3.2.2 附加阻尼控制器降低强迫振荡能量原理 18

3.2.3 基于UPFC及其附加阻尼控制器的抑制强迫振荡策略设计 20

3.2.4 UPFC与PSS在抑制强迫振荡方面的特性比较 21

3.3 仿真验证 21

3.3.1 四机两区系统简介 21

3.3.2 算例仿真与分析 23

3.4 本章小结 26

第四章 多类型扰动下的系统强迫振荡协调抑制 27

4.1 负阻尼机理的低频振荡概述 27

4.2 基于PSO算法的多类型扰动协调控制策略 28

4.2.1 PSO算法的原理 28

4.2.2 抑制多类型扰动的优化模型与协调策略 33

4.3 仿真验证 36

4.3.1 未接入UPFC 36

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