基于仿真软件PSS/E的低频振荡分析方法

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。     

基于改进多信号Prony算法的低频振荡传递函数降阶辨识及PSS的设计

为克服现代大规模电力系统分析的“维数灾”及电力电子元件难以用精确数学模型分析的问题，引入多信号到基于奇异值–总体最小二乘法的改进Prony算法中。在小波变换消噪和滤波的基础上，建立多信号的样本函数矩阵来提高辨识的准确性，在多信号的样本函数矩阵的基础上辨识振荡特征，并将计算结果应用到传递函数辨识中，然后依据辨识传递函数采用极点配置法进行电力系统稳定器(power system stabilizer，PSS)设计。IEEE 4机11节点系统验证了多信号改进算法对于信号特征和传递函数辨识结果的正确性和全面性，PSS加入实际仿真系统的效果说明了利用改进算法设计出的PSS效果优于利用传统线性化数学模型设计的PSS。     

基于RGA的FACTS控制器之间的交互影响研究

多台FACTS控制器之间的交互影响与协调是FACTS技术应用中亟待解决的问题,介绍了采用相对增益矩阵(RGA)方法,分析了多机电力系统中多台柔性交流输电系统(FACTS)控制器之间的交互影响。通过对4机两区域系统以及新英格兰系统两个实例的分析研究,分别采用频域分析、特征值分析以及时域仿真三种方法来验证RGA所得的结论,证明了RGA方法可以用来分析FACTS间的交互现象。     

支持向量机动态训练算法电力系统暂态稳定评估

在对比分析电力系统已有暂态稳定评估方法的基础上,提出一种以支持向量机模型为基础的动态训练算法.该方法将特征提取、样本训练融合在一起,动态产生一系列支持向量机模型,同时可以从维数较大的初始特征集中选择多组有效特征.实验表明,它可用于解决输入空间的可分性问题.在3机9节点以及16机68节点系统中的应用表明了该方法的有效性.     

基于聚类分析的电力系统暂态稳定故障筛选

提出了一种基于聚类分析的电力系统暂态稳定故障筛选方法.该方法建立在模糊C-均值(FCM)算法和矢量量化(VQ)方法的基础上,结合了两种聚类分析方法的优点,通过选择故障后系统的能量裕度作为特征变量之一,有效提高了故障筛选的准确性.采用新英格兰10机39节点系统和IEEE 50机145节点系统进行的测试证明了该方法的有效性.     

A two-time scale simulation for dynamic analysis of power systems

This paper proposes a two-time scale simulation approach of both short-term and long-term dynamics in power systems. The short-term transient period is analyzed by a full-time scale simulation while a quasi-steady state model of the power system is used to simulate long-term dynamics. The proposed method is inspired of Singular Perturbation theory to model the interaction between the short-term and long-term dynamics. Based on this interaction, a suitable criterion to determine when the quasi-steady state model of a power system can be considered as a uniform approximation of the full-time scale model is proposed, which also determines the appropriate switching time between models. The proposed method is demonstrated on the 10-machine, 39-bus New England system and a 46-machine, 190-bus equivalent Mexican system.     

TCSC自适应逆推控制器设计

针对可控串联补偿器TCSC(Thyristor Controlled Series Compensator)的动态过程和发电机阻尼系数不能精确测量的情况，将含有TCSC的单机无穷大系统用一个三阶微分方程表示，用自适应逆推方法设计了TCSC稳定控制器。在系统模型中考虑了TCSC的动态过程．同时保留了系统的非线性特性，运用自适应增益控制律进行参数的实时估计。仿真结果表明设计的TCSC稳定控制器能快速抑制振荡，保证单机无穷大系统的暂态稳定。     

Unified Analysis of Single Machine Equivalent and Trajectory Sensitivity to Formulate a Novel Transient Stability-constrained Optimal Power Flow Approach

Abstract—This article proposes a new transient stability constraint that permits quantifying the degree of instability of a power system from the active power dispatched by generators. Based on this constraint, which is derived from both single machine equivalent and trajectory sensitivity methods, a new transient stability-constrained optimal power flow is formulated in the Euclidian space to preventively control the transient stability in realistic power systems. The validity and the effectiveness of the proposed method are numerically demonstrated in the WSCC 3-machine, 9-bus and Mexican 46-machine, 190-bus systems.     

Voltage performance enhancement of DFIG-based wind farms integrated in large-scale power systems: Coordinated AVR and PSS

According to large extension of Doubly-fed induction generators (DFIGs) in power systems, providing appropriate operating condition for this type of wind technology in fault situations seems necessary. Among the essential requirements for DFIGs in fault situations, low-voltage ride-through (LVRT) capability is the utmost important issue. This paper deals with voltage performance enhancement of DFIG-based wind farms integrated in large-scale power systems under voltage dips. This aim is satisfied by create coordination between automatic voltage regulator (AVR) and power system stabilizer (PSS) of synchronous generators. In this research, the key tool for the coordination is fuzzy logic. The necessity of coordination for the designed fuzzy controller (fuzzy coordinator) is to eradicate destructive interactions between AVR and PSS in grid disturbance conditions. The fuzzy coordinator adjusts the AVR and PSS gains to enforce them to give the best performance in fault situations. The proposed coordination supports the voltage mitigation in the Point of common coupling (PCC) under voltage dips and decreases the reactive power requirement of the DFIGs. The performance of the designed fuzzy coordinator is demonstrated on the IEEE 10-machine 39-bus power system with different levels of DFIG-based wind farms contribution.     

改进的机电振荡模式相对局域性指标及其适应性

为了发展大规模互联电网态势感知的理论与方法,从依据系统规模灵活调整参数取值的角度出发,提出了一种改进的机电振荡模式相对局域性量化指标及其求解方法。首先,基于小信号模型分析系统状态矩阵的特征值,借助二分法在参与因子阈值闭区间内优化幂指数参数;然后,由归一化的参与因子获得机电振荡模式的局域性指标;相较于传统指标,所提指标计算效率高、实用性好;最后,借助MATLAB环境下的PST V3仿真工具进行IEEE 50机145母线系统和Kundur 4机11母线系统的仿真分析,结果证明了所提指标的有效性和适应性。     

Variable step-size prediction-correction homotopy method for tracking high-dimension Hopf bifurcations

A new algorithm named prediction-correction homotopy continuation method (PC-HCM) is proposed to track Hopf bifurcations in power systems. To overcome the calculation burden of conventional method, the secant prediction method is proposed to track Hopf bifurcation homotopy path. And the automatic step-size control strategy is produced to implement the step-by-step correction, which ensures the calculation accuracy and speed. Simulation results with WSCC 3-machine 9-bus system and NewEngland 39-bus system indicate that the proposed PC-HCM can trace Hopf bifurcations quickly and accurately.     

Coordinated design of PSS and TCSC to mitigate interarea oscillations

Thyristor controlled series compensator (TCSC) as a promising series flexible AC transmission system (FACTS) device is generally used for controlling the real power flow in transmission lines. It can increase the system stability as the complementary functionality by minimizing the power oscillations. The effectiveness of TCSC in its primary and supplementary applications depends on the selection of its optimal location and defining a proper input signal. In this paper, a new method based on the active power sensitivity approach is applied to find the optimal location of TCSC. In addition, Hankel singular values (HSVs) and right half plane-zeros (RHP-zeros) analyses have been proposed to find the most appropriate stabilizing input signal for the supplementary functionality of TCSC to damp out the interarea modes of oscillation. Finally, the optimal design of power oscillation damper (POD) and simultaneous coordinated design of power system stabilizer (PSS) and POD are implemented separately in a large-scale power system. The tuning problem of POD-TCSC parameters as well as the coordinated POD-TCSC & PSS are converted to a multi-objective optimization problem and solved using particle swarm optimization (PSO) algorithm. The performance of the proposed method has been validated through eigenvalue analysis and nonlinear time domain simulation in a 16-machine 68-bus test system. The simulation results show a satisfactory robust performance with an excellent capability in damping of local and interarea power oscillations.     

基于单机无穷大母线等值和轨迹灵敏度的暂态稳定最优励磁控制

为进一步降低电力系统暂态稳定控制代价,提出通过最优控制系统快速动态装置的设定值来保证系统在故障情况下的暂态稳定性。基于单机无穷大母线等值和轨迹灵敏度法,提出暂态稳定最优励磁控制二次规划模型,通过调整发电机电压调节器参考电压设定值来控制系统的稳定性。根据单机无穷大母线等值,在暂态稳定最优励磁控制模型中引入严格的暂态稳定判据;并借助轨迹灵敏度和稳定裕度指标提高计算效率。采用稳定裕度指标后避免寻找临界稳定轨迹,从而节省大量仿真时间。在新英格兰39节点10机系统和某省级692节点138机实际系统上的仿真结果验证了所提算法的可行性和有效性。     

面向电力仿真系统异构性的CIM扩展方法

针对公用信息模型(common information model,CIM)中与电力系统仿真相关的元件类及其拓扑关系,分析了CIM在机电暂态分析建模应用方面的不足,对CIM中同步电机类和能量用户类(用于负荷建模)的属性进行了扩展,并根据IEEE标准励磁系统的定义新建了励磁模型类。设计并实现了仿真信息交换测试系统,结合国内常用的BPA和PSS/E仿真软件构建了测试环境,以新英格兰10机39节点系统为对象进行了仿真测试,结果验证了模型扩展的有效性。     

基于累积贡献率和可解释人工智能的静态电压稳定裕度估计特征量筛选方法

利用海量量测数据估计大规模互联电网静态电压稳定裕度时,合理地选择输入量测信号和裕度估计算法是实现高质量裕度估计的基础。提出了一种基于累积贡献率和可解释人工智能的关键特征量筛选方法。给出了基于沙普利值加性解释理论可解释模型的输入特征贡献值量化方法,并依据贡献值大小对特征降序排列;采用基于累积贡献率增量的循环优化过程剔除冗余特征,形成关键特征子集;在系统关键特征优选的基础上,采用轻量梯度提升机算法实现静态电压稳定裕度在线估计。所提方法在保证估计精度的同时,大幅降低初始样本维度,解决特征过拟合问题,有效提升静态电压稳定裕度估计在线性能。基于WECC 3机9节点系统、IEEE 10机39节点系统以及IEEE 300节点系统的仿真分析验证了所提关键特征量筛选方法在电力系统静态电压稳定裕度估计中的有效性。     

遗传算法在暂态稳定评估输入特征选择中的应用

针对主成分分析中利用传统方法进行特征选择的缺陷,提出了基于遗传算法的特征选择方法。选择反映电力系统运行状态的特征变量,建立暂态稳定评估模型;为了提高数据处理的效率,首先对原始数据进行了动态聚类分析;对数据进行主成分分析后,以类内类间距离判据作为适应度函数,采用二进制编码形式的遗传算法进行特征选择。通过对3机9节点和10机39节点新英格兰系统的计算,验证了所选方法的有效性。     

Research on time-delay stability upper bound of power system wide-area damping controllers based on improved free-weighting matrices and generalized eigenvalue problem

A novel method is proposed in this paper to determine the time-delay stability upper-bound of the power system with wide-area damping controllers based on the improved free-weighting matrix and Generalized Eigenvalue Problem (gevp). First, a new class of Lyapunov–Krasovskii functional is constructed and its derivative function along the system is gained. Second, necessary loose items are added to the derivative function to reduce conservativeness, and the time-delay stability criterion based on the improved free-weighting matrices is formed. And then the time-delay stability criterion is equivalently transformed to a generalized eigenvalue problem. Thus by solving the gevp, the time-delay stability upper bound of the system is gained. Time-domain simulation tests on the IEEE 4-machine 11-bus system and IEEE 16-machine 68-bus system verify the correctness and effectiveness of the method.     

含双馈风电机组系统的广域阻尼控制器协调优化策略

为了提高含双馈风电机组系统抑制低频振荡的能力,提出一种基于自抗扰控制器的广域阻尼控制器协调优化策略。首先对含有双馈风电机组的电力系统进行建模;然后基于系统可观/可控性综合几何指标选择广域阻尼控制回路;最后利用人工蜂群算法对自抗扰控制器和广域阻尼控制器进行协调优化,以增强系统的稳定性。通过2区域4机系统和新英格兰10机39节点系统案例验证了所提出的方法在抑制含双馈风电机组系统低频振荡方面的可行性和有效性。     

基于负荷模式能量的电力系统低频振荡抑制策略

随着电力市场化和需求侧管理的快速发展,以及虚拟电厂聚合平台的逐步成熟,负荷可控性越来越强,为从负荷侧抑制低频振荡提供了可能。针对系统在振荡过程中出现的小干扰稳定问题,提出了基于负荷模式能量的电力系统低频振荡调控策略。构建电力系统小干扰负荷模式能量函数,从负荷的角度揭示电力系统低频振荡特性。基于负荷模式能量建立负荷的低频振荡评价指标与灵敏度指标,确定负荷参与改善系统小干扰特性的调控方式,对所有可控负荷进行排序,筛选出最优调控负荷。最后,对3机9节点系统和16机68节点系统算例进行仿真计算,结果表明所提控制策略可有效抑制系统振荡。     

基于进化策略的多机系统PSS参数优化

该文提出了一种基于进化策略的多机系统PSS参数优化的新方法。在这种方法中，目标函数设定为度量所有机电振荡模态性能的函数，将PSS的参数优化表示为带不等式约束的非光滑优化问题。进化策略用于该优化问题的求解，从而找出PSS的优化参数。进化策略属现代全局优化方法的一种，它对优化问题本身几乎无任何限制，冈其具有全局寻优能力，故可得到比常规优化方法更好的结果。且进化策略直接采用实型编码，因而可提高优化计算的效率。Anderson 3机系统和New England 10机系统的仿真结果表明，该方法是一种有效的参数优化方法，得到的优化参数对系统运行方式的变化具有良好的鲁棒性。