静止同步串联补偿器与静止无功补偿器的相互作用分析与协调控制

以同一系统中静止同步串联补偿器(static synchronous series compensator,SSSC)和静止无功补偿器(static var compensator,SVC)的共同作用为研究对象,建立了2者的数学参数模型,推导出控制器之间相互作用的量化关系式。通过控制参数分析和仿真分析得出结论：灵活交流输电(FACTS)装置的控制方式和电气耦合程度对SSSC和SVC的相互作用有很大影响。最后基于直接反馈线性化(DFL)方法设计了SSSC和SVC协调控制器,仿真结果验证了该协调控制策略的有效性。     

基于奇异值分解方法的FACTS交互影响分析

针对电力系统中多台灵活交流输电装置(FACTS)控制器之间可能存在的交互影响问题,以可控串联补偿器(TCSC)和静止无功补偿器(SVC)2种FACTS控制器为研究对象,提出了一种基于奇异值分解(SVD)的交互影响分析方法,定量分析了新英格兰10机39节点电力系统中同时装设TCSC和SVC时,2台FACTS装置之间可能存在的交互影响问题及电气参数对交互作用的影响。时域仿真结果验证了所提出的方法的有效性,表明电气距离的改变对TCSC与SVC间的交互作用有着较强的影响,增加电气距离,交互影响变弱,缩短电气距离则会加重两者之间的交互影响。     

SVC和TCSC控制器间动态交互影响分析

在考虑电力系统传递函数元素的稳态增益和动态特性的影响下,利用有效相对能量矩阵(EREA)的方法分析了2种典型柔性交流输电系统(FACTS)控制器间交互影响问题。对多FACTS控制器间的交互影响进行定量分析,为FACTS控制器的变量配对、选址等研究提供参考。通过含SVC和可控串联补偿器(TCSC)装置的新英格兰系统验证了在不同电气距离下交互影响的强弱程度,并采用时域仿真验证了所提分析方法的可行性和有效性。     

FACTS装置对含风电互联系统低频振荡特性分析

随着电力系统互联加强,风电并网容量的增加对电网的稳定运行影响越来越大。构建了以UPFC(Unified Power Flow Controller, UPFC)和SVC(Static Var Compensator, SVC)为代表的FACTS装置与含风电系统的数学模型。采用留数指标定位FACTS装置,设计了附加阻尼控制器(Additional Damping Controller, ADC)。基于IEEE 2区域4机互联系统,从特征根分析和时域仿真两个方面分析了FACTS装置对含风电互联系统低频振荡特性的影响。研究结果表明,加装附加阻尼控制器的FACTS装置能够维持母线电压以及发电机转速的稳定,增加互联系统联络线功率传输范围,抑制低频振荡引起的电网参数波动,改善了含风电电力系统的低频振荡特性。     

基于概率法的静止无功补偿器设计

采用概率论方法对SVC(静止无功补偿器)的辅助阻尼控制器进行鲁棒设计,电力系统的多运行状态采用概率法进行描述.首先根据负荷变化曲线求得系统特征根的概率属性,传统的特征根分析法被扩展成为概率特征根分析法.然后推导概率的特征根灵敏度指标,并成功地用于SVC阻尼控制器的定位,输入信号选择与参数设计.所提出的方法也通过一个两区域四机系统进行检验,证实了该方法的有效性.     

考虑FACTS配置的电网输电能力计算

灵活交流输电(FACTS)技术是提高电网输电能力的有效手段。文章基于连续潮流法,将静止无功补偿器(static var compensator,SVC)和可控串联补偿器(thyristor controlled series capacitor,TCSC)的稳态模型加入潮流方程中,建立了计及SVC和TCSC的可用输电能力计算模型。考虑到确定元件安装位置的重要性,利用连续潮流法求取系统极限功率点的输电能力,以该值与网络参数的灵敏度系数作为指标,选择最有利于提高输电能力的SVC和TCSC安装位置。对IEEE 30和IEEE 118节点系统进行的仿真计算证明了所提出模型和方法的有效性。     

基于多目标进化算法的TCSC与SVC控制器协调设计

以可控串补(TCSC)与静止无功补偿器(SVC)两种FACTS装置为研究对象,通过理论分析 指出了TCSC与SVC联合运行时不同控制目标间的矛盾,并通过一多机系统时域仿真实例,介绍 了TCSC与SVC控制器之间存在的交互影响。仿真表明:单独设计且运行良好的SVC与TCSC 控制器,并不能保证两者同时投运工况下控制器的性能。将FACTS功能控制器的协调问题转化 为一多目标优化问题,采用多目标进化算法(MOEA)优化控制器参数,得到一组Pareto优化解集, 时域仿真验证了协调控制器的控制效果良好。     

交直流混合系统低频振荡的概率特征根分析

研究低频振荡的传统特征根方法是基于单一的系统运行方式,而概率特征根分析则计及了较宽的系统运行方式变化。高压直流输电HVDC是一种典型的柔性交流输电FACTS装置,它可以改善系统的动态特性。将现有的概率特征根分析扩展到包含HVDC功能模块,能完成交直流混合系统的概率特征根分析。对四机两区域的交直流并联系统在选定的控制器参数下进行试算,结果表明,系统在多运行方式下研究交直流混合系统的低频振荡是可行的。     

柔性交流输电系统的研究进展情况

柔性交流输电系统(FACTS)是20世纪80年代中期由美国电力科学研究院(EPRI)N.G.Hingorani博士首次提出的,是综合电力电子技术、微处理和微电子技术、通信技术和控制技术而形成的用于灵活快速控制交流输电的新技术。目前,在我国部分高等院校、电力生产和设计部门及一些电气设备制造厂家都已开始FACTS技术方面的规划和研究试制工作。如在静止无功补偿器(SVC)、静止无功发生器(ASVG)、综合潮流控制器(UPFC)和可控串联电容补偿器(TCSC)等方面均已有较深入的研究。具体的研究进展如下:国内5个省电力系统已有SVC在500kV电网运行,效果…     

一类多静止无功补偿器阻尼控制器间的交互影响机理

随着电网中柔性交流输电系统(flexible AC transmission systems,FACTS)装置的增多,多FACTS同时运行时的交互影响研究成为热点之一。研究了多静止无功补偿器(static var compensator,SVC)阻尼控制中的交互影响现象及其作用机理。首先,基于时域仿真法提出了多台SVC装置控制器间存在的一类交互影响实例,进而基于多SVC机理分析的线性化模型和经典控制理论揭示了多SVC装置阻尼控制器间的交互作用机理,并提出了多SVC装置阻尼控制器的稳定分析判据,为多FACTS协调控制研究提供了重要参考。最后,使用两区四机系统算例和某实际电网进行了仿真分析,验证了研究结果的正确性。     

Coordinated design of probabilistic PSS and SVC damping controllers

This paper presents an application of probabilistic theory to the coordinated design of power system stabilizers (PSSs) and FACTS controllers, taking static VAr system (SVC) as an example. The aim is to enhance the damping of multi electro-mechanical modes in a multimachine system over a large and pre-specified set of operating conditions. In this work, conventional eigenvalue analysis is extended to the probabilistic environment in which the statistical nature of eigenvalues corresponding to different operating conditions is described by their expectations and variances. Probabilistic sensitivity indices (PSIs) are used for robust damping controller site selection and for optimization objective functions. A probabilistic eigenvalue-based objective function is employed for coordinated design of PSS and SVC controller parameters. The effectiveness of the proposed controllers is demonstrated on an 8-machine system.     

FACTS对电力系统静态安全性影响评价指标体系研究

针对目前评价灵活交流输电系统（FACTS）系统稳态性能影响指标的不足,结合FACTS设备自身控制潮流和电压的工作特性,提出了一套全面评估FACTS设备对系统静态安全性影响的指标体系。建立了基于运行状况的晶闸管控制串联电容器（TCSC）、静止无功补偿器（SVC）、统一潮流控制器（UPFC）可靠性模型,并基于该模型提出了FACTS设备的控制策略,该策略以状态量越限值最小为控制目标。建立了采用蒙特卡罗仿真的概率评估算法。通过IEEE-57节点的计算验证了所提指标体系和算法的有效性。     

Optimal placement and parameter setting of SVC and TCSC using PSO to mitigate small signal stability problem

This paper aims to select the optimal location and setting parameters of SVC (Static Var Compensator) and TCSC (Thyristor Controlled Series Compensator) controllers using PSO (Particle Swarm Optimization) to mitigate small signal oscillations in a multimachine power system. Though Power System Stabilizers (PSSs) associated with generators are mandatory requirements for damping of oscillations in the power system, its performance still gets affected by changes in network configurations, load variations, etc. Hence installations of FACTS devices have been suggested in this paper to achieve appreciable damping of system oscillations. However the performance of FACTS devices highly depends upon its parameters and suitable location in the power network. In this paper the PSO based technique is used to investigate this problem in order to improve the small signal stability. An attempt has also been made to compare the performance of the TCSC controller with SVC in mitigating the small signal stability problem. To show the validity of the proposed techniques, simulations are carried out in a multimachine system for two common contingencies, e.g., load increase and transmission line outage. The results of small signal stability analysis have been represented employing eigenvalue as well as time domain response. It has been observed that the TCSC controller is more effective than SVC even during higher loading in mitigating the small signal stability problem.     

发电厂厂用电系统中PSS与SVC稳定的离散分析

针对电力系统装置间相互协调运行的问题,对配有电力系统稳定器(PSS)的励磁系统发电机与装有静止无功补偿器(SVC)联合运行的发电厂厂用电系统,分别建立了PSS、SVC和带励磁系统的发电机数学模型并将其离散化,深入研究了PSS与SVC在厂用电系统近距离联合运行中的交互影响问题及提高SVC和PSS运行稳定性的方法。指出了在两者同时运行的情况下SVC控制器的设计需要考虑PSS放大倍数的影响,对SVC的比例、积分系数的改进设计的动态特性仿真表明,可以提高厂用电系统中SVC和PSS联合运行的稳定性。通过大量的仿真实验对离散分析的结果进行了验证。     

电压稳定的概率特征根分析

将传统的小干扰电压稳定性分析法扩展到基于一般性多机系统表达(GMR)技术的概率特征根分析环境。在正态分布的假设下,考虑了由节点功率运行曲线确定的系统多运行方式。某特征根位于复平面左半平面的分布概率表征了该模式的稳定程度,从而由特征根的分布概率和特征根对节点电压的电压失稳模式系数可以判断系统多运行方式时系统电压稳定的薄弱点,同时可为SVC的安装地点提供选择依据。在3机9节点系统上的计算分析表明了该方法的有效性,对目前多馈入交直流混合输电系统中凸现的电压稳定性问题的研究具有一定的意义。     

Choice of SVC location/signal and its controller design by probabilistic method

This paper presents a probabilistic algorithm for supplementary damping control design for the static var compensator (SVC). Conventional eigenvalue analysis is first extended to the probabilistic environment in which the statistical nature of eigenvalues, corresponding to the load duration curves, is described by their expectations and variances. A probabilistic sensitivity index (PSI) is then derived and successfully applied to the location, feedback signal and parameter selection of the damping controller of the SVC. System robustness can be guaranteed because the load variation has been taken into account in probabilistic representation. The effectiveness of the proposed approach is demonstrated on a two-area four-machine system.     

Hybrid linearization of a power system with FACTS devices for a small signal stability study: Concept and application

This paper deals with a hybrid linearization method of a power system with flexible AC transmission system (FACTS) devices. The linearized power system model provides useful information, which is necessary for the small signal stability study and the controller design. Although the algebraic linearization method provides an accurate and parameterized linear system, it may incur computation burdens for the large power system especially with multiple FACTS devices. The numerical identification of linearized system by utilizing input–output numerical data is highly versatile. However, quite amount of valuable information may be not fully utilized. In this paper, a hybrid method in which the algebraic and the numerical linearization technique are combined is presented. While both the power system and the FACTS devices are separately linearized by using algebraic method, the interaction terms between the power system and FACTS devices are numerically identified by adopting the quadratic optimization technique. The proposed hybrid linearization technique is tested on the WSCC system in which one thyristor-controlled series capacitor is installed. Both eigenvalue analysis and time-domain simulation results verify that the proposed method can effectively identify the linearized model of the power system with FACTS devices.     

Minimization of voltage sag induced financial losses in distribution systems using FACTS devices

Voltage sag can have significant economic consequences for different types of industries. Flexible AC Transmission System (FACTS) is originally developed for transmission networks but similar ideas are now starting to be applied in distribution systems. FACTS devices have become popular as a cost effective solution for the protection of sensitive loads from voltage sag. This paper presents the modeling of FACTS devices to minimize the voltage sag induced financial losses. The overall system financial losses due to voltage sag could be significantly reduced depending on the type of FACTS devices used. The short circuit analysis approach is used to incorporate the effect of these devices on financial losses. Voltage sag produced by balanced and unbalanced short circuits is analyzed by means of an analytical approach using system impedance matrix (Z_Bus) which incorporates FACTS devices. Two types of FACTS devices, which are most often used in practical applications, are considered in this study: Distribution Static Compensator (D-STATCOM) and Static VAR Compensator (SVC). Case studies based on a real Indian distribution system are used to illustrate the modeling method and the effectiveness of these devices in minimization of financial losses.