稳定器设计的就地相位补偿法在多机电力系统中的应用

为了演示和验证稳定器设计的就地相位补偿法在多机电力系统中的应用,介绍在多机电力系统中,就地补偿设计稳定器的2个应用实例。第1个实例是在多机电力系统中就地补偿设计电力系统稳定器(power system stabilizer,PSS),阻尼电力系统局部模振荡。第2个实例是就地补偿设计附加在静态同步补偿器(static synchronous compensator,STATCOM)上的稳定器,抑制多机电力系统中的区域模振荡,并给出在一个16机电力系统中的应用计算和仿真结果。     

一种用于电力系统低频振荡抑制的新能源电站阻尼注入控制器设计及特性分析

提出了一种基于新能源电站本地阻尼注入的电力系统稳定器(power system stabilizer,PSS)。该稳定器设计的基本思想是通过检测新能源电站端口频率信息,构建调制其输出有功或端口电压的补偿控制,依据系统功率平衡的原理,从而间接调节同步机组电磁功率输出达到抑制系统低频振荡的目的。所提出的有功功率和电压的阻尼注入控制采用统一的“增益+滤波+相位补偿”结构,其中相位补偿环节仅补偿频率测量及滤波环节在低频振荡频段的相移,无须外部电网的信息。同时基于构建的两机系统的扩展Heffron-Phillips模型,通过阻尼转矩法分析说明了光伏电站与同步发电机不同电气距离及控制参数变化情形下所提控制器均能提供较好的阻尼。最后,在Matlab/Simulink中搭建了含高比例光伏发电的四机-两区系统的仿真模型,验证分析考虑不同光伏渗透率、光照强度、接入点等场景下,所提出有功和电压阻尼注入控制的正确性及有效性。     

相位补偿法设计双频段PSS

为了同时提高本地振荡模式和区域振荡模式的阻尼特性,设计了一种双频段结构的电力系统稳定器.基于发电机六阶模型,把加速功率分解为PSS贡献的功率分量和不计PSS影响的分量,依据加速功率在复平面上的位置,确定了PSS的有效补偿相位区间.按照区域振荡和本地振荡模式的相位补偿要求,设计和分析了双频段PSS的结构.在一个八机系统下验证了所确定的补偿相位区间;配备双频段PSS后,机电振荡模式的阻尼特性提高较大.     

一种新型电力系统稳定器模型研究

针对电力系统低频振荡问题,本文提出一种新型低频段抑制增强的电力系统稳定器模型。该模型基于发电机机械运动模型,转速变化量经微分环节相位超前,加速功率变化量相位超前Δω轴90°,解决了PSS2B相位补偿主要为超前环节而造成的低频段增益小于高频段的问题。RTDS试验证明,该模型能够增强低频段系统阻尼,提高低频段有功振荡的抑制效果。     

输电线路联合区间振荡阻尼策略

建立了并联型与串联型FACTS(灵活交流输电系统)装置在输电线路中模型并推导了其补偿容量对线路输送功率的改变量,进一步证明了FACTS装置能通过改变线路功率来改变各发电机电磁功率从而增加系统阻尼。利用PMU(同步相量测量单元)所测量的联络线的功率变化的广域信号作为PSS(电力系统稳定器)附加阻尼信号,再联合FACTS装置能够增强系统阻尼的功能,使得对本地振荡模式和区间振荡模式均有较好的阻尼效果。建立了两区域MATLAB仿真模型,验证了理论分析的正确性。     

水电机组引起的超低频振荡特性及抑制措施研究

近年来,直流孤岛送出系统中陆续出现了振荡频率低于0.1Hz的超低频振荡现象,严重危害电网的安全稳定运行。研究表明,由于水电机组中存在水锤效应,若调速器控制参数设置不合理,系统的阻尼和稳定性会恶化,水电机组比例过高会使得系统中出现超低频振荡。针对此问题,首先建立含PID型水电机组调速器的多机系统线性化状态空间模型,求解出超低频振荡模式。然后,采用阻尼转矩分析法分析调速器控制系统的阻尼特性,并提出一种基于相位补偿原理的调速器侧电力系统稳定器(governorpowersystem stabilizer,GPSS)设计方法,可以通过GPSS来增加调速器控制系统阻尼,从而抑制系统的超低频振荡。最后,在3机9节点系统中,采用特征分析法,根据参与因子和根轨迹对超低频振荡特性进行分析得出:调速器控制系统确实深度参与了超低频振荡现象,通过合理设置调速器控制参数可以增大超低频振荡模式的阻尼比。同时,在单机单负荷和4机2区域仿真系统中验证了该文所设计的GPSS抑制超低频振荡的有效性。     

基于阻尼转矩分析法的UPFC阻尼通道选取与附加稳定器的协调设计

在关于统一潮流控制器(UPFC)抑制系统低频振荡研究的基础上,将阻尼转矩分析(DTA)方法扩展至包含UPFC的多机电力系统,依据稳定器的阻尼转矩产生、传递和分配的机理,提出了应用DTA指标指导UPFC最佳阻尼通道的选取,并通过四机两区域系统验证了DTA方法的合理性。鉴于UPFC多个阻尼通道可附加多个稳定器以抑制多个振荡模态,提出一种UPFC多个稳定器的协调设计方法,通过DTA指标选取UPFC多个阻尼通道,采用Hooke-Jeeves直接搜索法协调各阻尼系数,再应用相位补偿法设计稳定器参数。仿真结果验证了该方法能够有效抑制多模态(包括区间与区内)振荡。     

电力系统稳定器与现场试验

通过广泛使用的单机无穷大系统小干扰线性化模型,分析了发电机组应用快速高放大倍数的励磁调节系统后,系统产生低频振荡的原因。对电力系统稳定器（PSS）抑制低频报荡的原理即相位补偿原理进行了分析。同时分析了PSS各个环节功能及参数对阻尼低频振荡的影响。并给出了100MW发电机组PSS相位校正的实测数据,表明了PSS对低频振荡抑制的效果。     

电力系统稳定器相位补偿准确度探究

随着现代电力系统互联低频振荡问题愈发突出,电力系统稳定器广泛应用于抑制振荡。PSS的传统理论是负阻尼机理,以Philips-Heffron模型为基础,通过为系统提供增加阻尼转矩提高系统稳定性。理论上。相位滞后角度可通过计算从PSS输入点到暂态电势间传递函数的相位差来确定,实际常用机端电压代替暂态电势。这能否保证其在各种工况和振荡模式下相位补偿的准确度是值得讨论的。从机理上探究PSS作用,推导了机端电压和暂态电势间传递函数,并分别讨论了参考电压扰动、状态变量初始值和机械功率扰动对上述相位关系的影响,有助于解决现阶段PSS运行存在的问题。     

电力系统稳定器影响频率振荡的机理及阻尼分析方法

频率振荡是有功频率控制过程的小扰动稳定问题。已有研究集中于发电机调速器和原动机环节的分析。电力系统稳定器也可用于抑制频率振荡。分析了发电机励磁系统影响频率振荡的机理,当负荷具有电压调节效应时,则发电机励磁系统通过影响负荷电压进而影响负荷功率,从而对频率振荡产生影响。给出了频率偏差通过电力系统稳定器、励磁、网络、负荷等环节影响电磁功率的过程,利用阻尼转矩法计算电磁功率阻尼系数并分析了电力系统稳定器的影响。提出了多机系统中不同发电机电力系统稳定器对频率振荡阻尼影响大小的评估方法,选择影响大的发电机进行参数优化可更加有效地提高频率振荡阻尼。利用IEEE的4机2区系统对分析结论进行了仿真验证。     

Robust coordinated design of multiple and multi-type damping controller using differential evolution algorithm

A robust coordination scheme to improve the stability of a power system by optimal design of multiple and multi-type damping controllers is presented in this paper. The controllers considered are power system stabilizer (PSS) and static synchronous series compensator (SSSC)-based controller. Local measurements are provided as input signals to all the controllers. The coordinated design problem is formulated as an optimization problem and differential evolution (DE) algorithm is employed to search for the optimal controller parameters. The performance of the proposed controllers is evaluated for both single-machine infinite-bus power system and multi-machine power system. Nonlinear simulation results are presented over a wide range of loading conditions and system configurations to show the effectiveness and robustness of the proposed coordinated design approach. It is observed that the proposed controllers provide efficient damping to power system oscillations under a wide range of operating conditions and under various disturbances. Further, simulation results show that, in a multi-machine power system, the modal oscillations are effectively damped by the proposed approach.     

利用多端统一潮流控制器阻尼多模态振荡

研究了多机系统中使用统一潮流控制器(UPFC)抑制电力系统多模态振荡的可行性.首先推导了作为UPFC概念延伸的多端统一潮流控制器(MUPFC)的非线性动态模型和线性化的Phillips-Heffron模型.利用UPFC和MUPFC具有多个控制回路的特点,提出在其多个控制回路上附加多个阻尼控制器来阻尼多模态振荡.通过模态分析,采用可控性指标对系统中的各个弱阻尼模态选取有效的控制回路,并设计了附加阻尼控制器.仿真结果表明,通过该方法确定的在一个UPFC或MUPFC上设置的多个附加阻尼控制器能够成功实现对电力系统多模态振荡的抑制.     

Design of a nonlinear power system stabilizer using synergetic control theory

Electromechanical oscillations of small magnitude and low frequency exist in the interconnected power system and often persist for long periods of time. Power system stabilizers (PSSs) are traditionally used to provide damping torque for the synchronous generators to suppress the oscillations by generating supplementary control signals for the generator excitation system. Numerous techniques have previously been proposed to design PSSs but many of them are synthesized based on a linearized model. This paper presents a nonlinear power system stabilizer based on synergetic control theory. Synergetic synthesis of the PSS is based fully on a simplified nonlinear model of the power system. The dynamic characteristics of the proposed PSS are studied in a typical single-machine infinite-bus power system and compared with the cases with a conventional PSS and without a PSS. Simulation results show the proposed PSS is robust for such nonlinear dynamic system and achieves better performance than the conventional PSS in damping oscillations.     

Robust decentralized multi-machine power system stabilizer design using quantitative feedback theory

A new robust power system stabilizer (PSS) design using Quantitative Feedback Theory (QFT) for damping electromechanical modes of oscillations and enhancing power system stability is proposed in this paper. The design procedure is carried out on a multi-input–multi-output (MIMO), non-minimum phase and unstable plant. A multi-machine electric power system with system parametric uncertainties is considered as a case study. To show the effectiveness of the QFT technique, the proposed method is compared with a conventional PSS (CPSS) whose parameters are tuned using the classical lead-lag compensation and genetic algorithms. Several nonlinear time-domain simulation tests indicate that the suggested control scheme is robust to the changes in the system parameters and also to successfully reject the disturbances. The results also show that the performance of the QFT method given in this paper is more desirable than CPSS and genetic algorithm (GA).     

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。     

A Novel Fuzzy Rule Matrix Design for Fuzzy Logic-based Power System Stabilizer

In this paper, fuzzy logic-based power system stabilizer (FPSS) is designed to have effective damping. As to achieve impressive performance of a controlled plant, the rule base/fuzzy rule matrix (FRM) of a fuzzy logic controller (FLC) is designed by trial–error method, which is a time-consuming process. In this paper, a systematic procedure is given to design FRM for effective damping of single-machine infinite-bus (SMIB) and two-area four-machine ten-bus power system. To design the novel FRM, the existing rule tables, proposed by different researchers, are tested with SMIB system, and empirical relationships have been drawn. The response validity and rule justification is carried out using linguistic phase-plane trajectory method. Finally, the contribution to design FRM is made to get effective damping for SMIB as well as a multi-machine system. The effectiveness of the FPSS based on the proposed FRM over a wide range of operating conditions on SMIB system and the comparison of system response without PSS, with Conventional PSS, and with FPSS is carried out. Similarly, the multimachine power system is considered without PSS and with FPSS, and performance comparison is carried out. The response of FPSS with proposed FRM enables to show the effective damping of system oscillations.     

Optimal tunning of type-2 fuzzy logic power system stabilizer based on differential evolution algorithm

In this paper, a type-2 fuzzy logic power system stabilizer with differential evolution algorithm is proposed. As an extension of type-1 fuzzy logic theory, type-2 fuzzy logic theory can effectively improve the control performance by uncertainty of membership function especially when we have to confront with less expert knowledge or unpredicted external disturbances. The corresponding parameters and rule base of type-2 fuzzy logic power system stabilizer are optimally tuned by using differential evolution algorithm for multi-machine power system. Through simulation under different operational conditions, the results demonstrate the effectiveness of the proposed approach for damping the power system electromechanical oscillations.     

抑制频率振荡的电力系统稳定器参数优化

超低频频率振荡是有功频率控制过程的小扰动稳定问题。由于负荷电压调节效应使得无功电压控制和有功频率控制产生耦合,传统用于抑制低频振荡的电力系统稳定器(PSS)可用于抑制频率振荡。提出了在多机系统中选择抑制频率振荡的PSS的方法,该方法综合了PSS对低频振荡和频率振荡的影响大小。构建了抑制频率振荡的PSS参数优化模型,该模型仍然以低频振荡模式阻尼比作为优化目标,但加入频率振荡对应频段发电机励磁系统相位要求作为约束,保证机组励磁系统为频率振荡提供足够的正阻尼。采用粒子群优化算法对模型进行求解得到PSS最优参数。仿真结果验证了所提方法的有效性。