含无功补偿装置的风电并网系统暂态电压稳定性研究

针对大规模风电并网后系统的暂态电压稳定性问题,阐述了暂态电压失稳的机理以及暂态电压稳定性的分析计算方法,介绍了2种重要的无功补偿装置SVC和STATCOM。采用BPA软件对国内某一实际电网进行了仿真分析,结果表明,风速变化和系统发生短路故障均会对系统的暂态电压稳定性造成影响,导致系统的电压水平降低。装设SVC或STATCOM对系统电压均有支撑作用,且STATCOM对电压的支撑作用更加明显。     

FACTS对多机系统静态电压稳定性的影响

针对一个两区域薄弱互连的4机系统,利用负荷裕度指标和P－U曲线平坦度指标,衡量了FACTS设备对系统静态电压稳定性的影响。连续潮流法潮流计算结果表明SVC,STATCOM,TCSC等3种FACTS设备都可以在不同程度上改善系统的静态电压稳定性,改善的效果与设备参数的选取有关。对于所研究的4机系统,为了提高系统的静态电压稳定性,装设TCSC进行串联补偿可以取得比装设SVC,STATCOM进行并联补偿更好的效果。     

SVC在南方电网西电东送中的应用研究

随着西电东送工程的推进,SVC装置将不断在南方电网西电东送通道中投用。本文介绍了2010年南方电网已经安装的SVC装置的应用情况,并以2010年云广±800 kV直流输电工程投运后的南方电网丰大运行方式为背景,采用新版PSD工具仿真研究大扰动下SVC对扰动下系统稳定性的影响。仿真结果表明:SVC能明显改善扰动下电网的电压稳定性和功角稳定性;楚雄站SVC能有效抑制换流站无功投切引起的电压波动和降低直流双极闭锁引起的过电压;桂林站和独山站的SVC均带有直流融冰功能,提高线路抗冰能力,保障系统稳定。     

动态无功补偿技术在西电东送通道中的应用研究

为了解安装SVC(Static VAR Compensator,静止无功补偿器)对提高广西电网动态电压支撑能力和对南方电网西电东送通道输电容量、安全稳定水平的影响,对西电东送通道电压无功灵敏度进行了分析,研究主通道配置SVC对提高通道输电能力、对大故障扰动模式下系统安全稳定控制策略的影响,及暂态电压恢复特性和各种配置方案的经济性比较,研究确定了动态无功电压支撑薄弱节点;提出了西电东送通道安装SVC的较好位置.研究结果对电网规划和生产运行具有重要的参考价值.     

用SVC和STATCOM改善风力发电动态性的仿真比较

异步风力发电机在运行时需要吸收无功功率,以维持电压和功率的动态稳定。现代电力电子技术的快速发展,使得FACTS元件得到更多应用,将SVC、STATCOM运用于风力发电中,能有效改善风电场的电压稳定和故障后的系统的暂态稳定性。通过MATLAB/SIMULINK建立仿真模型,验证了SVC、STATCOM对风力发电系统稳定的作用,并进行了比较。     

SVC与STATCOM在大容量输电通道上的应用比较

静止无功补偿器( SVC) 和静止同步补偿器( STATCOM) 都是无功补偿的重要装置,在故障下的电压支撑、提高暂态稳定极限、阻尼功率振荡等方面对两者进行分析比较。仿真指出在输电通道上安装大容量无功补偿装置,单个节点上安装SVC和STATCOM对维持节点电压的能力一般,STATCOM好于SVC;在提高暂稳极限方面,STATCOM的效果好于SVC;在增强系统阻尼效果上,同容量的STATCOM明显优于SVC,同调节范围时两者阻尼控制效果基本一致;STATCOM响应速度高于SVC,但响应速度对控制效果影响不大。     

SVC与STATCOM在大容量输电通道上的应用比较

静止无功补偿器( SVC) 和静止同步补偿器( STATCOM) 都是无功补偿的重要装置,在故障下的电压支撑、提高暂态稳定极限、阻尼功率振荡等方面对两者进行分析比较.仿真指出在输电通道上安装大容量无功补偿装置,单个节点上安装SVC和STATCOM对维持节点电压的能力一般,STATCOM好于SVC;在提高暂稳极限方面,STATCOM的效果好于SVC;在增强系统阻尼效果上,同容量的STATCOM明显优于SVC,同调节范围时两者阻尼控制效果基本一致;STATCOM响应速度高于SVC,但响应速度对控制效果影响不大.     

静止同步补偿器与传统静止无功补偿器的比较与分析

随着灵活交流输变电(FACTS)技术的不断发展,出现了很多新型的FACTS装置。比如基于全控型电力电子器件(如GTO晶闸管与IGBT等)的STATCOM就是其中之一,它与传统的补偿器SVC相比在技术上有着很多的优势。介绍FACTS装置中的STATCOM与SVC,并对它们在电压支撑、动态仿真、控制方法、谐波和经济性等方面进行综合分析与比较。     

静止同步补偿器与传统无功补偿器的比较

随着灵活交流输电（FACTS）技术的不断发展,出现了很多新型的FACTS装置。比如基于全控型电力电子器件（如GTO晶闸管与IGBT等）的STATCOM就是其中之一,它与传统的补偿器SVC相比在技术上有着很多的优势。介绍FACTS装置中的STATCOM与SVC,并对它们在电压支撑、动态仿真、控制方法、谐波和经济性等方面进行综合分析与比较,STACOM具有显著的优越性。     

对比研究链式STATCOM与SVC对电网的暂态支撑能力

大型互联电网若缺乏充足的动态无功支撑将面临严重暂态电压失稳现象,在输电系统的关键位置安装快速可控的无功补偿装置将有效抑制这一现象.重点研究了电网故障下动态无功补偿装置SVC和链式STATCOM的暂态电压支撑能力以及暂稳极限提高能力.针对链式STATCOM的独特结构,提出了一种改进分相控制策略.基于Matlab/Simulink搭建了系统仿真模型,仿真结果证实故障下链式STATCOM的暂态电压支撑能力略高于SVC,暂稳极限提升能力明显优于SVC,同时验证了改进分相控制策略可确保不对称故障期间链式STATCOM对系统的暂态支撑作用正常发挥.     

Performance Comparison of Distance Protection Schemes for Shunt-FACTS Compensated Transmission Lines

This paper presents a comparative study of the performance of distance relays for transmission lines compensated by shunt connected flexible ac transmission system (FACTS) controllers/devices. The objective of this study is to evaluate the performance of various distance protection schemes on transmission lines with shunt-FACTS devices applied for midpoint voltage control. The impact of two types of shunt FACTS devices, static var compensator (SVC) and static synchronous compensator (STATCOM) on the transmission line distance protection schemes is studied for different fault types, fault locations and system conditions. The power system elements and the shunt-FACTS devices with their associated controllers are modeled using RSCAD/RTDS software. The results are based on the performance of commercial distance relays using a real time digital simulator (RTDS).     

Performance of distance relays on shunt-FACTS compensated transmission lines

This paper presents a study of the performance of distance protection relays when applied to protect shunt Flexible AC Transmission System (FACTS) compensated transmission lines. The objective of this study is to evaluate the performance of distance relays on transmission lines with FACTS devices applied for mid point voltage control. Effect of two types of shunt FACTS devices, Static Var Compensators (SVC) and Static Synchronous Compensators (STATCOM) are studied. The study is conducted in three stages. First the situation is studied analytically, where the errors introduced in the impedance measurement due to the presence of shunt FACTS devices on the line are analyzed. In the second stage, the situation is simulated using transient simulation software, EMTDC. In this method, the response of FACTS devices for different fault conditions and system conditions is also modeled. This method brings out some unique problems that would be experienced by the distance relays due to some specific characteristics of the FACTS devices. Finally, the findings are confirmed by testing a commercial distance relay using a Real Time Digital Simulator (RTDS). The results obtained by testing the commercial relay validate the analytical and simulation studies.     

FACTS装置在风电场中的无功补偿原理与仿真

分析风电场并网运行存在的无功补偿及电压稳定问题的产生机理,在固定电容器组作为一种传统的无功补偿方法逐渐显现弊端时,将柔性交流输电系统(FACTS)设备运用到风电场以提高其运行的稳定性。以恒速恒频异步风力发电机为研究对象,采用变桨距控制方式。以Matlab/Simulink为平台,实现风电场的电气输电系统、各种风速的建模。在各种风速扰动和电网故障的情况下,分别对加入静止无功补偿器和静止同步补偿器的风电场进行仿真,得到的结果可以证明两者在风电场无功补偿方面的积极作用,并对两者的性能优劣进行对比。     

A new modeling and placement of shunt FACTS devices in the secondary voltage regulation environment

Recently, the Secondary Voltage Regulation (SVR) is installed in some power systems in order to ensure the coordination voltage control devices. In other hand, the shunt FACTS devices such as the Static Var Compensator (SVC) and the STATic COMpensator (STATCOM) are extensively used for the local voltage control without any coordination with other voltage control devices, without any reciprocal coordination. In this paper, new models of SVC and STATCOM are proposed to be adopted in power flow models that include the SVR. The proposed models are implemented and tested on a model of the Italian power system. Furthermore, a new method based on sensitivity analysis is proposed to find the most sensitive placements for the installation of SVC and STATCOM. The results obtained show the highly computational performance of the propose models and also the effectiveness of the sensitivity analysis to find the best placements of SVC and STATCOM taking into account the SVR.     

Voltage stability boundary and margin enhancement with FACTS and HVDC

Voltage stability is a major concern of today’s power system, especially under heavily loaded conditions because of reactive power limits. FACTs devices are very effective solution to prevent voltage instability and voltage collapse due to fast and very flexible control. In this paper, the impacts of SVC, STATCOM, TCSC and HVDC on voltage stability boundary (VSB) in P–Q plane have been studied. The bus impedance matrix and load flow results are used to find the voltage stability boundary. The Z_bus is modified to take into account the effect of FACTS on VSB. The variable susceptance model for SVC and variable series impedance power flow model for TCSC are used in Newton Raphson’s method. The STATCOM is modelled as variable voltage source connected in series with an equivalent impedance of the shunt connected transformer. Similarly HVDC is also modelled as two STATCOMs connected at each end of the line one as rectifier and another as inverter. Some important bus and line stability indices are evaluated to determine the most effective location for SVC/STATCOM and TCSC/HVDC respectively in order to achieve the maximum enhancement of voltage stability margin. The study has been carried out on IEEE-14 bus and IEEE-30 bus test systems using MATLAB programming. A comprehensive study is done to compare the effectiveness of FACTS devices and HVDC on voltage stability margins.     

STATCOM与SVC在电力系统运行中的比较分析

静止无功补偿器（SVC）和静止同步补偿器（STATCOM）是2种常见的新型柔性交流技术装置,在输出特性、对提高输电系统稳定性、响应时间、谐波分析、经济性等方面对STATCOM和SVC进行了比较,并通过仿真得出了STATCOM较SVC具有响应速度快,控制方法先进、电流谐波含量少、经济性好等优点。     

基于PSCAD的风电场低电压穿越无功支撑仿真研究

首先分析风电场低电压穿越(low voltage ride-through,LVRT)能力,然后介绍以双馈感应发电机(doubly-fed induction generator,DFIG)为主体的风电场模型以及静止同步补偿器(static synchronous compensator,STATCOM)的控制策略。最后将STATCOM和静止无功补偿器(static var compensator,SVC)分别应用到含风电场的无穷大系统中,在电力系统仿真软件PSCAD上搭建模型,并对系统故障状态进行仿真,在此基础上分析STATCOM和SVC的无功补偿特性,并对补偿效果进行比较。仿真结果表明无功补偿装置可以在系统故障后提供无功支撑,提高了风电场的低电压穿越能力,并且STATCOM无功补偿性能较SVC更优。     

SVM based zonal setting of Mho relay for shunt compensated transmission line

Presence of shunt FACTS (Flexible Alternating Current Transmission System) device significantly affect the performance of protection system and may create security and reliability issues. This paper introduces a novel approach for zone identification in transmission line employing shunt FACTS devices such as Static Var Compensator (SVC) and Static Synchronous Compensator (STATCOM). The technique depends on the modified apparent impedance seen by the impedance relay for all possible operating conditions. In this technique the Support Vector Machine (SVM) is used for discriminating faulty zone (zone 1 or zone 2). In addition an optimization technique viz. Genetic Algorithm (GA) is used to optimize SVM parameters. A typical 230 kV system was simulated in PSCAD/EMTP software and the results show that the proposed scheme is secure, accurate and reliable under the wide variation in power system parameters like load angle, fault resistance, fault location, inception angle and compensation level.