某垃圾发电电厂两机无刷励磁系统PSS试验仿真分析

以某35 MW垃圾发电机组励磁系统为研究对象,建立了完整的两机无刷励磁系统数学模型,同时使用某仿真平台建模,搭建了两机无刷励磁系统仿真模型,并对建立的模型进行了PSS投退工况下的仿真研究,对比分析了现场试验得到的实际波形与仿真结果,两者比较接近,验证了所建模型的有效性以及建模工作的必要性。

基于DIgSILENT/PowerFactory跨区域电网PSS选址及有效性验证

基于DIgSILENT/PowerFactory模态分析功能,得出了发生机电振荡时局部和区域模态各电机参与因子的模态柱状图、向量图,以辨识PSS最佳安装位置。通过特征值分析和时域仿真,验证了系统安装PSS后的稳定性,对复杂系统PSS安装地址的选取至关重要。

Transient Stability Analysis of Power System by Coordinated PSS-AVR Design Based on PSO Technique

In this paper, Power System Stabilizer (PSS) and Automatic Voltage Regulator (AVR) are coordinated to improve the transient stability of generator in power system. Coordinated design problem of AVR and PSS is formulated as an optimization problem. Particle Swarm Optimization (PSO) technique is an advanced robust search method by the swarming or cooperative behavior of biological populations mechanism. The performance of PSO has been certified in solution of highly non-linear objectives. Thus, PSO technique has been employed to optimize the parameters of PSS and AVR in order to reduce the power system oscillations during the load changing conditions in single-machine, infinite-bus power system. The results of nonlinear simulation suggest that, by coordinated design of AVR and PSS based on PSO technique power system oscillations are exceptionally damped. Correspondingly, it’s shown that power system stability is superiorly enhanced than the uncoordinated designed of the PSS and the AVR controllers.

PSS/E与PowerWorld风电机组模型对比

单一的电力系统仿真软件无法满足含大规模风电并网系统的所有仿真需求,需根据需求选择恰当的仿真工具,因此对常用的PSS/E和PowerWorld软件的风电机组模型进行对比。首先介绍了当前主流软件PSS/E、PSLF、BPA程序、PowerWorld中风电机组模型的结构和功能,并针对PSS/E和PowerWorld,比较了发电机-换流器模块、有功功率控制模块、机械-调速模块的工作机理。然后以国际大电网会议推荐的标准风电并网系统CIGRE B4-39网络为例,进行了基于PSS/E与PowerWorld的风电并网仿真分析。仿真结果表明:PSS/E风电机组模型的锁相环在电压畸变的情况下能够快速锁定相位,抑制高次谐波;PowerWorld的风电机组模型在控制有功功率的过程中,能有效抑制风电场无功功率波动对有功出力的影响。最后,指出PowerWorld、PSS/E和BPA程序的适用场合。

Applications of Localized Phase Compensation Method to Design a Stabilizer in a Multi-machine Power System

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。

Fast-speed self-powered PEDOT:PSS/α-Ga_(2)O_(3)nanorod array/FTO photodetector with solar-blind UV/visible dual-band photodetection

Theα-Ga2 O_(3)nanorod array is grown on FTO by hydrothermal and annealing processes.And a self-powered PEDOT:PSS/α-Ga_(2)O_(3)nanorod array/FTO(PGF)photodetector has been demonstrated by spin coating PEDOT:PSS on theα-Ga_(2)O_(3)nanorod array.Successfully,the PGF photodetector shows solar-blind UV/visible dual-band photodetection.Our device possesses comparable solar-blind UV responsivity(0.18 mA/W at 235 nm)and much faster response speed(0.102 s)than most of the reported self-poweredα-Ga_(2)O_(3)nanorod array solar-blind UV photodetectors.And it presents the featured and distinguished visible band photoresponse with a response speed of 0.136 s at 540 nm.The response time is also much faster than the other non-self-poweredβ-Ga_(2)O_(3)DUV/visible dual-band photodetectors due to the fast-speed separation of photogenerated carries by the built-in electric field in the depletion regions of PEDOT:PSS/α-Ga_(2)O_(3)heterojunction.The results herein may prove a promising way to realize fast-speed self-poweredα-Ga_(2)O_(3)photodetectors with solar-blind UV/visible dual-band photodetection by simple processes for the applications of multiple-target tracking,imaging,machine vision and communication.

Performance of PSS to Damp Power Oscillations Caused by an HVDC Link in AC-DC Power System

HVDC (High Voltage Direct Current) systems are increasingly being applied to improve power system operation and controllability. However, inappropriate setting of HVDC controller may have a detriment effect on the system performance. Generally, PSS (Power System Stabilizer) is known as a simple concept, easy to perform, and computationally effective to enhance damping of power system oscillations through excitation control of synchronous generator. This paper examines the effectiveness of the PSS to enhance the dynamic performance of AC-DC power systems and to compensate the negative damping of HVDC system. The dynamic performance is evaluated by examining the system response to various disturbances. In order to ensure the reliability of the simulation test results as well as the performance of the PSS, detailed HVDC modeling is adopted using SimPowerSystems toolbox in the MATLAB, and some important conclusions are drawn.

PSS and SVC Controller Design using Chaos, PSO and SFL Algorithms to Enhancing the Power System Stability

In this paper, the Authors present the designing of power system stabilizer (PSS) and static var compensator (SVC) based on chaos, particle swarm optimization (PSO) and shuffled frog leaping (SFL) Algorithms has been presented to improve the power system stability. Single machine infinite bus (SMIB) system with SVC located at the terminal of generator has been considered to evaluate the proposed SVC and PSS controllers. The coefficients of PSS and SVC controller have been optimized by Chaos, PSO and SFL algorithms. Fi-nally the system with proposed controllers is simulated for the special disturbance in input power of genera-tor, and then the dynamic responses of generator have been presented. The simulation results show that the system composed with recommended controller has outstanding operation in fast damping of oscillations of power system and describes an application of Chaos, PSO and SFL algorithms to the problem of designing a Lead-Lag controller used in PSS and SVC in power system.

Identification of the Optimum Locations of Power System Stabilizers in a Multimachine Power System Using Second Order Eigenvalue Sensitivity Analysis

This research paper deals with the identification of the best location of the Power System Stabilizers (PSS) and also the tuning of PSS parameters in order to improve the overall dynamic stability of multi machine power systems. The location of PSS is determined by identifying the critical modes and their corresponding first and second order eigenvalue sensitivities. In this formulation, sensitivity analysis of a particular mode can be performed with only its eigenvalues and their left and right eigenvectors. The simplicity and efficiency of this approach sharply contrast to the complexity of the traditional approach, where all eigenvalues and eigenvectors are required at the same time. The effectiveness of this method in selecting the optimum location for placement of PSSs is compared with the participation factor method. The proposed sensitivity theory used to identify the best PSS location in a five machine, eight bus El-Metwally and Malik System to increase the damping of both local and inter area modes for various operating conditions.

PSS参数误整定引起有功波动原因分析

随着电网供电区域不断扩大,电网结构日趋复杂,大型弱联系电网固有的自然阻尼有时会使电力系统之间发生有功低频振荡。通过发电机的菲利普斯-海佛容模型分析可知,在远距离、重负荷送电的情况下,加之快速励磁系统普遍应用,更是加剧了这一状况,为了改善新型电力系统动态安全稳定性影响,作为励磁系统的附加装置电力系统稳定器(PSS)发挥了高效且经济作用。目前应用广泛的双输入加速功率型电力系统稳定器PSS 2A,通过适当的环节参数整定,可以在特定的频段内对励磁系统滞后特性进行有效补偿,使励磁系统提供足够的正阻尼,使系统发生的低频振荡快速衰减。然而当PSS参数整定不合理,对励磁系统调节产生不正确的补偿,就有可能影响发电机稳定运行,严重情况下甚至会引发低频振荡。本文以发电机的Phillips-Haffron模型分析为基础,从发电机电磁转矩的角度分析,在Δδ-Δω坐标系中得到了励磁系统调节对发电机稳定性的影响。最后通过一起PSS参数误整定分析,验证了等效加速功率型PSS 2A模型仿真的正确性。

基于Prony方法的大型互联电网PSS参数优化设计

提出了一种完全基于仿真曲线Prony分析的电力系统稳定器(PSS)参数优化设计方法。该方法通过对仿真曲线的Prony分析辨识系统的弱阻尼区域振荡模式信息,以提高区域振荡模式下的阻尼为优化目标,在限定的参数空间中进行PSS参数优化设计。采用单纯形法对PSS参数进行优化,以Prony方法辨识的PSS参数作为单纯形区域的初始中心点可克服算法的收敛性问题。云南电网发电机组实际PSS参数优化设计的结果表明:在云南电网多种运行方式下,均可很好地抑制系统的区域振荡,验证了PSS参数优化设计方法的有效性和鲁棒性。所提出的基于Prony算法的PSS参数优化方法优于传统PSS设计方法,适用于大型互联电网发电机组的PSS设计。

有功型PSS抑制低频振荡机理及反调特性

介绍了MEC5220型励磁调节器的原理及系统产生低频振荡的原因,分析了励磁调节器的阻尼特性。通过对有功型电力系统稳定器(PSS)的研究发现,PSS虽能抑制振荡,但有功型PSS使用的前提是机械功率变化相对电气功率变化近似不变,当调节发电机原动机出力时,PSS得到的信号远大于需要的信号,就会造成励磁电压和无功功率大幅变化,即反调。通过实例证实了有功型PSS反调特性,并提出了防止其危害的对策。

基于特征值分析法的PSS最佳安装地点的确定

介绍了电力系统低频振荡的特征值分析方法 ,并采用特征值分析法所得出的结果———参与因子来选择最佳的电力系统稳定器 (PSS)安装地点 ,以提高弱振荡模式的阻尼。采用发电机的转子角速度对弱振荡模式的参与因子作为指标 ,选择最佳的PSS安装地点。通过对一个较大规模的电力系统进行实例分析 ,说明在采用此方法所确定的最佳安装地点上安装PSS 。

PSS控制过程中的借阻尼现象与负阻尼效应

根据考虑PSS控制的线性化系统模型,利用特征值的数学性质,揭示了PSS控制过程中的借阻尼现象,即:PSS提供给机电振荡模式的阻尼是从非机电模式转移来的。另外,结合三机系统算例并通过相量图分析,阐明了多机系统PSS控制过程中的负阻尼效应现象,即:PSS在增加一些机电振荡模式阻尼的同时,将减少另一些机电振荡模式阻尼,并指出负阻尼效应现象是多机系统的一种本质特性。因此,PSS在系统中要合理地配置和恰当地选择参数,以使系统机电振荡模式能够从非机电模式那里“借”来足够而合理的阻尼。所以,PSS在系统中要合理地配置和恰当地选择参数,以使系统机电振荡模式能够从非机电模式那里“借”来足够而合理的阻尼。

一种基于协同控制理论的分散非线性PSS

为提高电力系统稳定器的动态性能及鲁棒性,提出一种基于协同控制理论的分散非线性电力系统稳定器(powersystem stabilizer based on synergetic control theory,SPSS)设计方法。首先针对同步发电机及励磁系统模型,根据协同理论,构造出合适的流形,然后推导出SPSS的控制规律,进一步实用化后,得到一种基于协同控制理论的实用的SPSS,由于SPSS的所有输入信号均为本地易测量信号且与网络参数无关,从而能实现分散控制。最后,将所设计的SPSS用于3机6节点电力系统进行小扰动和大扰动仿真验证。仿真结果表明,与常规的相位补偿型的PSS相比,所提出的SPSS能够在较大的运行范围内向系统提供充分的阻尼,并对模型误差不敏感,具有很好的鲁棒性。

BPA与PSS/E的暂稳态模型比较和数据转换

为实现将BPA数据格式转化为PSS/E数据格式,在对BPA和PSS/E两种仿真软件暂稳态数学模型分析比较的基础上,编写相应的数据转换接口程序。分别用3机9节点算例和某交直流互联系统的等值系统进行仿真计算,以测试数据转换的正确性。同时对用两个软件计算得出的交流系统和交直流互联系统的潮流计算结果以及纯交流系统的暂态稳定计算结果进行比较,显示两个软件的计算结果比较接近,并对产生差异的原因进行了解释。

基于混沌优化算法的PSS和直流调制的协调优化

为解决交直流系统中直流调制之间,以及直流调制和PSS之间可能存在的不稳定的相互作用,本文将混沌优化算法应用于包含多馈入直流输电系统的交/直流互联电力系统,进行各直流调制和电力系统稳定器(PSS)之间的协调控制研究。该算法将直流调制和PSS的参数调节问题被转化为基于Lozi映射的混沌优化算法的优化问题,在全局协调的控制方式下增强整个系统对交流系统机电振荡的阻尼。并以中国南方电网的网络为实例说明了该方法的有效性、鲁棒性及其优越性。

基于PSS/E的华东电网低频振荡分析方法

基于仿真软件PSS/E提出了一种分析华东电网低频振荡特性的方法,结合PSS/E的特征值分析法和Prony分析法,在发电机采用经典模型的条件下通过特征值分析计算系统振荡模式的频率、振型和参与因子,而在发电机采用详细模型并考虑励磁系统详细模型的条件下通过Prony分析法计算系统振荡模式的阻尼。对4机两区域系统和新英格兰10机39节点系统的特征值分析表明,振荡模式的频率、振型和参与因子并不随发电机采用模型的不同而有很大变化。因此,文中提出的方法可以方便地适用于实际大规模电力系统的低频振荡分析。对华东电网的低频振荡特性进行分析,得到了该电网区域间振荡模式的频率、阻尼、振型及参与因子。

多频段PSS结构设计和参数协调

为了在提高PSS对振荡模式选择性的同时,改善传统多频段电力系统稳定器(PSS)结构复杂、频段数固定的问题,提出了一种新型的功率输入型多频段PSS,并对PSS的结构进行了频率特性分析。在系统多运行方式下,使用概率灵敏度分析法进行分析,确定PSS的频段个数;进而根据该PSS参数设计方法,利用非线性规划技术对参数进行协调优化。在一8机系统内进行了验证,表明该PSS可以根据具体需要确定补偿频段数,既可作为单频段PSS仅提高某一个模式的阻尼比,也可作为多频段PSS同时兼顾多个振荡模式。