含有STATCOM的电力系统次同步谐振研究

在超高压远距离输电系统中采用串联电容补偿后,在某种运行方式或补偿度的情况下,会发生电力系统的次同步谐振(SSR)现象。柔性交流输电技术在电力系统中有着广阔的应用前景,是近年来电力系统研究的前沿课题之一。而静止同步无功补偿器(STATCOM)是FACTS家族的重要成员,是并联型补偿装置的代表。采用扫频-复转矩法分析系统的次同步谐振,摒弃传统的PID控制策略,设计多目标控制算法实现对STATCOM装置的系统级控制,使其在进行无功补偿的同时可以阻尼电力系统次同步谐振现象,这就显得既有理论又有现实意义。     

含有SMES电力系统次同步谐振的抑制研究

随着中国社会主义市场化经济日趋深化,国民经济日益迅速的发展,用电负荷迅速增长,电网的输送容量也在不断地增大,输电距离不断加长。在这样的发展背景下串联补偿作为提高线路输电能力的手段在电网规划中越来越受到关注,但是在超高压远距离输电系统中采用串联电容补偿后,在某种运行方式或补偿度的情况下,会发生电力系统的次同步谐振（SSR）现象。柔性交流输电技术在电力系统中有着广阔的应用前景,是近年来电力系统研究的前沿课题之一。而超导磁储能系统（SMES）是FACTS家族的新型重要成员,是储能补偿装置的代表。采用扫频一复转矩法分析系统的次同步谐振,摒弃传统的PID控制策略,设计多目标控制算法实现对SMES装置的系统级控制,使其在进行无功补偿的同时可以阻尼电力系统次同步谐振现象,这既有理论又有现实意义。     

STATCOM附加电压控制抑制次同步谐振的理论和仿真

提出了应用静止同步补偿器(STATCOM)附加电压控制抑制电力系统次同步谐振(SSR)的控制策略,并详细分析了其作用机理。以某典型串联补偿输电系统为实例,通过电磁暂态仿真验证了该控制策略的有效性。与利用静止无功补偿器(SVC)进行SSR抑制方案的仿真比较表明,同等容量下,应用文中提出的附加电压控制策略的STATCOM对系统SSR的抑制效果优于SVC。该方法为解决国内外输电工程所面临的SSR问题提供了参考,也为STATCOM装置的推广应用提供了依据。     

基于SVC利用远端信号缓解次同步谐振研究

串补输电线路有发生次同步谐振的潜在危险。灵活交流输电技术被广泛的研究用来抑制电力系统的这一问题,但是对于在国内电网应用较多,且技术成熟的静止无功补偿装置的研究相对较少。本文利用安装在线路中点的静止无功补偿辅助控制装置,缓解次同步谐振,并利用PSCAD/EEMTDC仿真软件在IEEE第一标准测试模型基础上进行仿真测试。     

采用STATCOM与SEDC的多机系统次同步谐振抑制措施

并列同型的多台汽轮机组通过带串补线路送出时可能发生次同步谐振(subsynchronous resonance,SSR)。出力不均衡时,各机组轴系扭振行为不一致,在幅值和相位上均有差别。以双机系统为例,对并列多机系统发生SSR时各机组轴系扭振行为的差异进行了研究。时域仿真结果表明,将各机组发电机转速均取作输入信号时,仅采用静止同步补偿器(static var compensator,STATCOM)便可抑制所有机组的轴系扭振,但是抑制速度缓慢;以网侧STATCOM为主、机侧附加励磁阻尼控制(supplementary excitation damping,SEDC)为辅的联合SSR抑制措施可以结合SEDC和STATCOM各自作为SSR抑制措施的优点,快速有效地抑制多机系统SSR。     

TCSC与SVC在抑制电力系统次同步谐振中应用比较

针对串补输电引起的电力系统次同步谐振SSR（振荡SSO）,基于IEEE次同步谐振第一标准测试系统,采用测试信号法和时域仿真法,全面深入地比较了TCSC与SVC在抑制系统SSR（SSO）中的作用和效果.研究发现：TCSC与SVC均能有效地抑制次同步谐振,但由于两者分属串、并联设备,故又有各自的特点.投入相同容量时,TCSC较SVC抑制效果更优,提升电气阻尼能力更强.在相同抑制效果下所需TCSC容量要少于SVC,但投资偏高.两者注入电网谐波均为奇次谐波,且以3、5、7次为主.后期运行维护自动化程度较高,应根据装置的不同薄弱环节进行针对性的维护.     

具有直流输电的电力系统次同步谐振的研究

建立了直流输电系统的复频域模型，导出了任意网络结构下多机交直流电力系统的复 频域网络方程，从而将复数力矩系数法应用到具有直流输电的电力系统次同步谐振的研究。 对一个3机系统的计算结果证实了所提出方法的正确性和有效性。     

电力系统次同步谐振抑制措施综述

在远距离大容量的输电线路中加入串补电容可以提高系统的输送能力,但是会出现次同步谐振问题,危及发电机组轴系安全和电力系统的稳定。阐述了次同步谐振问题产生的机理及现有的抑制措施。并对工程实际中常用的几种抑制措施的原理、功能及经济性进行了分析和比较,指出了各种措施的优缺点。最后根据经济技术比较的结果,给出了具有较好应用前景的抑制方案。     

无功补偿器抑制电力系统次同步振荡的研究

介绍了串补输电系统次同步振荡的产生机理和抑制电力系统次同步振荡的常用措施。分析了静止无功补偿器（SVC）抑制次同步振荡的基本原理,并进行了控制器的设计。基于次同步振荡研究的IEEE第一标准模型,利用电力系统电磁暂态仿真软件PSCAD／EMTDC,对该模型分别在不安装SVC和安装SVC时进行了时域仿真,得出了SVC抑制次...     

采用SVC抑制发电机次同步谐振的理论与实践

针对静止无功补偿器(SVC)在抑制次同步谐振(SSR)方面的理论与应用进行了研究。分析了SVC抑制SSR的基本工作原理;提出了SVC抑制SSR的各种控制策略;讨论了SVC的容量估计方法。以托克托工程为背景分析了SVC抑制SSR的效果。仿真结果表明SVC能有效抑制SSR的发生,为解决国内交流串补输电工程中SSR问题提供了参考,也为SVC装置的更好应用提供了依据。     

电力系统次同步振荡的分岔分析

基于非线性系统分岔理论，分析电力系统次同步谐振现象。利用通用的连续和分岔软件-AUTO，分析一个含串联补偿的电力系统次同步谐振(SSR)中的分岔现象。从非线性分岔角度揭示出SSR产生的原因是系统发生分岔后不稳定的极限环导致。当发生电力系统次同步谐振时，可能会产生环面分岔和周期折叠分岔等一系列复杂的周期轨道分岔。时域仿真的结果验证了分岔分析结果的有效性。     

Analysis of subsynchronous resonance with generalized unified power flow controller

The Generalized Unified Power Flow Controller (GUPFC) is one of the most versatile flexible ac transmission system (FACTS) controllers which controls the active and reactive power flows in multiple transmission lines originating from a substation while controlling the sending end bus voltage. The sending end bus voltage is regulated by control of shunt reactive current while the active and reactive power flows in the transmission line are regulated by series injected voltages. This paper reports the analysis and study of Subsynchronous Resonance (SSR) characteristics of hybrid compensated system with GUPFC. The various operating mode combinations of series and shunt converters are considered to investigate their effect on SSR characteristics. The methods of analysis of SSR with GUPFC is based on the evaluation of damping torque, eigenvalues of the system and transient simulation. The computation of damping torque considers D–Q model of GUPFC to determine the torsional mode stability. The study is performed on a system adapted from IEEE Second Benchmark Model (SBM). The results demonstrate the effectiveness of series real injected voltage in mitigating the SSR.     

一种用于次同步谐振研究的电力系统外网等值方法

针对结构复杂的串补输电系统的外网采用何种方法等值及等值后系统保留多大规模这一问题,基于现有的对次同步谐振模式在电网中的传递特性的认识,提出了一种适用于次同步谐振研究的电力系统外网等值方法.根据短路等效阻抗及等值前系统平衡运行状态,确定外网等值参数,并结合次同步谐振研究结果的参数敏感性对等值参数进行适当处理.以系统频率阻抗作为评价指标确定外网合适的等值规模.该方法简单方便,易于实现,适用于结构复杂的串补输电系统的次同步谐振评估分析.通过南方电网的应用算例验证得出,采用该方法进行外网多点等值时等值参数的简化处理及等值规模的判定方法对次同步谐振研究结果的影响很小,从而说明了该方法的有效性.     

Application of an auxiliary controlled static var system for damping subsynchronous resonance in power systems

In this paper a novel concept of a static var system (SVS) auxiliary controller application for damping subsynchronous resonance in power systems has been proposed and demonstrated. An SVS controller, known as the combined reactive power and frequency (CRPF) auxiliary controller has been developed and incorporated in the SVS control system located at the middle of a series compensated long transmission line. The studies are conducted on a system having a similar spread of the torsional modes as the first IEEE benchmark model. The proposed SVS auxiliary controller stabilizes all the torsional modes over a wide operating range. A digital computer simulation study has been performed, using a nonlinear system model, to illustrate the effectiveness of the proposed SVS auxiliary controller.     

采用STATCOM抑制多机系统次同步振荡的理论与仿真

针对远距离大容量输电系统中出现的多机系统次同步振荡(SSO),分析了利用STATCOM附加电流的抑制策略,采用了模态解耦控制方法,详细介绍了控制器参数整定过程.在此基础上,建立了网络中各元件的端口等效导纳矩阵.采用分散消元的复转矩系数法,可以简化全系统复频域网络方程的生成,便于分析发电机组的等效电气阻尼特性.最后以此方...     

An active power control strategy for a DFIG-based wind farm to depress the subsynchronous resonance of a power system

This study presents a novel auxiliary damping control strategy to depress subsynchronous resonance (SSR) oscillations in nearby turbine generators. In the proposed control strategy, SSR damping is achieved by adding turbine generator speed as a supplementary signal at the active power loop of the rotor-side converter (RSC) of doubly-fed induction generator (DFIG)-based wind farms. To design the SSR auxiliary damping controller, a transfer function between turbine generator speed and the output active power of the wind farms was introduced to derive the analytical expression of the damping coefficient. Then the damping effect of the active power of the DFIG-based wind farms was analyzed, and the phase range to obtain positive damping was determined. Next, the PID phase compensation parameters of the auxiliary damping controller were optimized by genetic algorithm to obtain the optimum damping in the entire subsynchronous frequency band. The last, the validity and effectiveness of the proposed auxiliary damping control were demonstrated on a modified version of the IEEE first benchmark model by time domain simulation analysis with the use of DigSILENT/PowerFactory.     

利用含储能装置的STATCOM阻尼电力系统多模态振荡

研究了多机系统中使用储能装置与静止无功发生器(STATCOM)的集成抑制电力系统多模态振荡的可行性。推导了集成电池储能系统(BESS)的STATCOM的非线性动态模型和线性化Phillips-Heffron模型。利用STATC0M/BESS能够和系统自由交换有功功率和无功功率的特点,在每个控制回路上设计附加阻尼控制器阻尼多模态振荡。基于可控性指标确定STATCOM/BESS的安装地点并为各模态选择控制回路,使用人工鱼群算法进行多个阻尼控制器间的协调优化。仿真结果表明,单个STATCOM/BESS能够成功实现电力系统多模态振荡的抑制;阻尼效果受容量限制的影响,容量大时阻尼效果好。     

Application of subsynchronous damping controller (SSDC) to STATCOM

In this paper a novel supplementary subsynchronous damping controller (SSDC) is proposed for the STATic synchronous COMpensator (STATCOM) which is capable of damping out subsynchronous oscillations in power system with series compensated transmission lines. An auxiliary subsynchronous damping controller (SSDC) for a STATCOM using the generator rotor speed deviation signal as the stabilizing signal has been designed to damp subsynchronous oscillations. Eigenvalue analysis and transient simulations of detailed nonlinear system are considered to investigate the performance of the controller. Robustness of the controller has been analyzed by facing the system with disturbances leading to significant changes in generator operating point. This paper deals with a cascaded multilevel converter model, which is a 48-pulse (three levels) source converter. The IEEE Second Benchmark (SBM) model is considered for the analysis and the complete digital simulation of the STATCOM within the power system is performed in the MATLAB/Simulink environment.     

STATCOM versus SSSC for power system stabilization

Flexible alternating current transmission systems (FACTS ) are gaining more attention in power utilities because of their advantages of controllability, reliability, and operation over a wide range. Static synchronous compensator (STATCOM) and static series synchronous compensator (SSSC ) are prominent FACTS topologies; they have the ability to instantaneously regulate active/reactive powers and stabilize the power system following severe disturbances. In this paper, STATCOM and SSSC are compared with regard to their damping action on power system oscillations. The comparison is extended to the controller design strategies. Two distinct meta‐heuristic optimization approaches, namely chaos (CO) and simulated annealing (SA), are recommended for the optimal design of the SSSC and STATCOM damping controller. To assess the promising FACTS topology, a single‐machine infinite bus system is subjected to several disturbances while operating at different loading levels. MATLAB/Simulink is used as a platform to investigate the dynamic performance of the system under consideration with STATCOM and SSSC . Simulation results reveal the superiority of SSSC in damping power system oscillations in terms of response speed and stability margin. Moreover, the CO optimization scheme seems to outperform the SA algorithm in terms of computation requirements and global optimal convergence. © 2017 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.