改善关键线路潮流问题的可控串联补偿装置研究

文中研究了可控串联补偿装置在关键线路潮流控制中的作用。通过建立用于分析可控串联补偿装置潮流作用的电路模型,列写功率方程,使用解析方法,画出功率运行范围、有功功率和无功功率变化曲线等;分析了单个可控串补对线路输送功率的作用,通过进一步解析,重点分析了UPFC+固定串补电容对线路输送功率作用;考虑到经济性后,对UPFC+固定串补电容方案进行了最优投资建模,并给出了求解流程。通过对江苏电网中关键线路的作用分析,明确了UPFC+固定串补电容方案的合理性,并验证了求解流程的有效性。     

基于电容电压同步下TCSC暂态特性的数学描述

当选择电容电压作为同步信号时 ,可控串被 (TCSC)的暂态过程会出现明显的超调和振荡 ,对于这一现象 ,前人还从未给出相应的机理解释。该文以晶闸管导通角为建模对象 ,采用拓扑建模法建立了能描述电容电压同步下TCSC暂态特性变化规律的二阶差分数学模型。借助该模型可分析影响暂态过程的相关因素 ,进而从本质上揭示了电容电压同步下TCSC的暂态机理。数字仿真结果验证了所建模型的正确性。     

基于可控串补的故障限流器

研究了一种基于可控串补结构的故障限流器,可对电网进行功率控制并在故障时降低短路电流水平。该故障限流器主要由并联电容、并联电感、反并联晶闸管和与开关并联的串联电感构成。开关用于装置在串补和限流模式间进行切换,装置正常工作时运行于串补模式,故障时迅速切换到限流模式运行,有效限制短路电流。该装置在原有串补装置上改动较少,可为现有设备增加故障限流功能做参考。通过Matlab/Simulink软件对系统进行仿真研究,结果表明此装置能够控制功率并限制短路电流,是电力系统中可靠的保护和控制装置。     

线路故障定位系统的方法

分析了可控串补装置对输电线路行波测距法的影响;研究了故障电流行波通过可控串补装置(TCSC)的暂态过程;提出了利用可控串补装置对端站数据的故障测距方法,避免可控串补装置对测距的影响。     

南方电网天平可控串联补偿装置

我国第1个500kV可控串联电容补偿装置——南方电网平果串补站，于2003年7月建成投产。本文着重介绍其在南方电网西电东送中的作用、串补的主要参数、基本控制原理及其过电压保护策略。天平可控串补为我国可控串补及串补的研究、设计和运行提供了宝贵的经验，起到了示范作用。     

TCC方式和TCR方式可控串补的控制特性仿真研究

国内目前可控串补采用的是晶闸管控制电抗器(TCR)方式。TCR方式的可控串补的确可以解决远距离交流输电的诸多技术难题,但所带来的新的技术问题也相当突出,如控制特性的严重非性线,容易产生并联谐振过电压,电容电流严重过载,相控条件下的控制范围非常有限等。文章在全面总结TCR控制方式和控制特性的基础上,研究了晶闸管直接控制电容器(TCC)方式的可控串补技术,TCC通过直接控制电容器实现串补度的直接、连续可调,它既继承了TCR方式的技术优点,又克服了如上所述的TCR方式的技术难题,实现了整个可控容抗工作区域的连续可调,大幅度扩大了可控串补的工作区域,提高了可控串补度。     

伊冯可控串补过电压保护控制及主动绝缘配合研究

文章介绍东北伊冯５００ｋＶ可控串补装置的过电压保护控制策略及主动绝缘配合设想和措施,提出了采用主动绝缘配合方法后,伊冯可控串补的过电压保护水平,氧化锌取压器的容量,晶闸管电流等主要技术参数及其概率分布。     

带有串联电容补偿装置的10kV配电网线路短路故障暂态过程研究

配电网是电力系统直接连接用户的关键供电环节。采用串联电容补偿装置来补偿线路电抗的串补技术,在输电线路中可提高交流输电线路输电容量、提高系统的稳定性等优点。串补在配电网中可以改变线路R-L-C参数,有效改善沿线电压质量,但串补的接入会影响配电网的暂态过程,因此需要研究串补的暂态工作特性尤其是发生概率居首位的短路故障下。本文以陕西地区一条典型的10 kV配电线路为例,基于先前的研究成果,在线路串补安装位置及补偿度最优补偿方式下,计算分析了线路不同短路故障下的电磁暂态过程及其影响,获得了串补电容保护装置配置参数对暂态过程的影响规律和保护效果。     

可控串补装置主动过电压保护分析与研究

介绍了主动过电压保护的概念.通过动态模拟实验研究了利用可控串补硬件bypass运行模式限制系统故障期间串补电容两端过电压、减小短路电流的作用,提出了在系统发生短路故障时,减小短路电流,保护电容器的有效控制策略.     

可控串补装置主动过电压保护分析与研究

介绍了主动过电压保护的概念,并通过动态模拟试验研究利用可控串补硬件bypass运行模式限制系统故障期间串补电容两端过电压、减小短路电流,提出了在系统发生短路故障时,减小短路电流、保护电容器的有效控制策略.     

伊冯可控串补主要器件基本工作条件及总体工作能力探讨

本文介绍伊冯可控串补主要器件在稳态和准稳态下的工作条件，其中包括正常运行状态，Ｎ－１运行状态和暂态稳定调节状态下电容器，旁路电抗、晶闸管和ＭＯＶ的工作条件。     

伊冯串补动态特性仿真及对电网稳定性影响研究

对可控串补的强补和振荡阻尼程序(POD)功能做了详细阐述,并对可控串补的补偿能力进行了仿真,根据仿真结果给出了串补提升系数与线路电流大小的关系曲线。最后对伊冯串补的投运对电网稳定水平的影响进行仿真研究。     

TCSC control design for transient stability improvement of a multi-machine power system using trajectory sensitivity

This paper discusses the effects of thyristor controlled series compensator (TCSC), a series FACTS controller, on the transient stability of a power system. Trajectory sensitivity analysis (TSA) has been used to measure the transient stability condition of the system. The TCSC is modeled by a variable capacitor, the value of which changes with the firing angle. It is shown that TSA can be used in the design of the controller. The optimal locations of the TCSC-controller for different fault conditions can also be identified with the help of TSA. The paper depicts the advantage of the use of TCSC with a suitable controller over fixed capacitor operation.     

相控电容器式可控串补特性分析

揭示了相控电抗器式可控串补与相控电容器式可控串补的对偶特征。用对偶原理阐述了相控电容器式可控串补的性能及相控特点。分析说明了串补电容器、GTO网的电流电压峰值与串补线路电流峰值、串补电容器的工频容抗值之间的关系，这对于理论上确认相控电容器式可控串补的优越性非常重要。阐述了相控电容器式可控串补具有阻尼次同步谐振和抑制低频功率振荡的能力；相控电抗器式可控串补装置的动态性能是一个其时间常数不大于工频0．25周期的一阶惯性环节。     

A Combined Frequency Converter for Soft Acceleration of Induction Electric Drives with Heavy Starting Conditions

The usability of a thyristor frequency converter with a supplementary controlled series compensator for soft starting of induction motors with high torque of inertia of actuating mechanisms is considered as an alternative to transistor converters. It is shown that the supplemental device, in the form of a transistor–capacitor convertor, can be considered as an adjustable capacitor, the equivalent capacitance of which can be varied from very large values (to a maximum of infinitely large) to some fixed minimum value. The voltage of an adjustable series capacitor provides the desired switching conditions of thyristor inverter, and the capacitive reactance ensures the compensation of reactive power consumed by the induction motor and thyristor inverter, reducing the current load of the motor and converter. The addition of a thyristor current converter with a controlled series compensator of reactive power in the form of a transistor–capacitor unit makes it possible to carry out a soft start of induction motors similar to the starting modes of synchronous machines. Simulation results confirming the achievement of the desired effect are presented. It is shown that the supplemental device in the form of transistor–capacitor converter is a robust system well adaptable to various conditions of electric-drive operation. The functional equivalence of a transistor frequency converter and thyristor frequency converter with a supplemental transistor–capacitor unit with a substantially lower cost of the latter makes possible a new mechanism for soft starting of powerful electric drives with induction motors under conditions of high torques of inertia of actuating mechanisms.     

伊敏-冯屯可控串补控制策略的RTDS实验研究

采用RTDS实时仿真工具验证了我国东北电网伊敏－冯屯500 kV交流输电架空线路可控串联补偿控制器的各项控制性能,检验了可控串联补偿装置的稳态运行特性,研究了可控串联补偿装置的阻抗阶跃特性和运行模式转换特性,最后通过三相故障的工况验证了可控串联补偿装置提高系统暂态稳定性尤其是阻尼低频功率振荡的作用。     

面向超高压电网的故障限流器的应用研究

针对迫切需要解决的大负荷中心短路电流超标的问题,在介绍了短路电流限制器研究现状,阐述了新型串联谐振型限流器(SCCL)工作原理后,用等面积法分析了单机无穷大系统中SCCL提高系统暂态稳定裕度的机理,并比较了串联电抗器与谐振型限流器的优缺点。谐振型参数设计是工程设计的难点,其中抑制因子代表着限流器限流能力,其取值要综合系统需求考虑。保证电容器可靠旁路是谐振型限流器的关键技术,多重化旁路开关技术能有效抵御电容器过压击穿的风险。基于优化参数的大量仿真实验证明:主电路设计合理,旁路开关电气强度降低,电容器在有效保护范围内。     

An active‐passive capacitor‐commutated converter for HVDC systems with a three‐phase voltage‐source PWM converter

This paper introduces a new approach to the capacitor‐commutated converters (CCCs) for HVDC systems. A small‐rated three‐phase voltage‐source PWM converter is connected between a series commutation capacitor and thyristor converter through matching transformers. The PWM converter acts as auxiliary commutation‐capacitor for the thyristor converter while the series passive capacitor acts as the main commutation capacitor. The capacitance, which is the sum of the small‐rated active and series passive capacitors, is variable, so that stable commutation is obtained. In CCCs, commutation failure occurs when the AC bus voltage is recovered whereas the proposed combined commutation‐capacitor can achieve successful commutation for both rapidly decreasing and increasing AC bus voltages. The basic principle of the proposed active–passive capacitor‐commutated converter is discussed in detail. Then, constant margin angle control with a constant firing angle of the thyristor converter is proposed using a function generator block. Digital simulation demonstrates the novelty and effectiveness of the proposed active–passive capacitor‐commutated converter. © 2005 Wiley Periodicals, Inc. Electr Eng Jpn, 151(1): 66–75, 2005; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20030     

可控串补等值阻抗的计算方法研究

利用小信号分析法 ,对可控串补的频率响应特性进行了研究。对可控串补输入小信号电流 ,求取可控串补中各电压电流 ,并利用傅里叶分析方法求得各信号的相应频率分量 ,进而求得可控串补的频率响应特性。该研究对可控串补系统的次同步谐振以及其他相关的谐波研究有重要意义 ,分析方法对其他FACTS元件的研究有借鉴作用。EMTP仿真验证了本文方法的有效性。     

Fuzzy based damping controller for TCSC using local measurements to enhance transient stability of power systems

This paper proposes a local fuzzy based damping controller (LFDC) for thyristor controlled series capacitor (TCSC) to improve transient stability of power systems. In order to implement the proposed scheme, detailed model of TCSC, based on actual behavior of thyristor valves, is adopted. The LFDC uses the frequency at the TCSC bus as a local feedback signal, to control the firing angle. The parameters of fuzzy controller are tuned using an off-line method through chaotic optimization algorithm (COA). To verify the proposed LFDC, numerical simulations are carried out in Matlab/Simpower toolbox for the following case studies: two-area two-machine (TATM), WSCC three-machine nine-bus and Kundur’s two-area four-machine (TAFM) systems under various faults types. In this regard, to more evaluate the effectiveness of the proposed method, the simulation results are compared with the wide-area fuzzy based damping controller (WFDC). Moreover, the transient behavior of the detailed and phasor models of the TCSC is discussed in the TATM power system. The simulation results confirm that the proposed LFDC is an efficient tool for transient stability improvement since it utilizes only local signals, which are easily available.