基于随机矩阵理论的配网故障可观的PMU优化配置方法

定义故障在全网最不灵敏节点发生时可检测为随机矩阵理论下的全网可观。相同故障发生在不同节点时对配网影响程度不同,对应的随机矩阵理论指标MSR的跌落程度不同。提出了配网故障时全网可观的PMU优化配置方法。分别在所有节点设置单相和两相接地故障,得到2种情况下全网的电压数据并计算相应的MSR;对2种MSR进行加权,计算出各节点灵敏系数;以灵敏度最低的节点发生故障时全网可观为目标,按灵敏程度逐次减去不灵敏节点的PMU并计算相应的MSR,直到故障不可检测,得到的PMU配置即为最后配置。以IEEE36节点和IEEE39节点模型进行仿真,验证了在该PMU优化配置方案下,可用随机矩阵理论对配网进实时监测,在故障发生时能准确检测到故障并确定故障发生的时刻。     

基于微型同步相量测量单元的配电网单相接地故障定位

准确定位配电网的故障对于提高供电的可靠性和减少连续停电所造成的损失有着重要的意义,微型同步相量测量单元(micro-phasor measurement units,μPMU)的应用,为配电网故障准确定位提供更多的信息.为此,提出了一种基于μP MU信息的极限梯度提升和基于遗传算法的支持向量机的配电网单相接地故障定位方...     

基于信号分析的电力系统低频振荡辨识方法研究综述

随着PMU测量装置在电网中的广泛应用,基于PMU实测信息的WAMS系统已成为区域互联电网低频振荡在线监测的重要手段。重点对低频振荡的发生机理和基于信号特征辨识的电力系统低频振荡分析方法的进行了综述,并结合工程实际探讨了未来大电网低频振荡在线监测的技术发展方向,指出未来低频振荡在线监测应紧密结合一体化智能调度自动化系统的技术发展,实现全局的在线协同监测与分析。     

基于μPMU的主动配电网故障定位方法研究

摘要： 准确的故障定位有助于提高配电网络的稳定性。随着分布式发电和电动汽车的接入,传统配电网逐渐向主动配电网发展,传统故障和保护装置已无法满足,这对故障定位技术和装置提出了新的要求。文章提出了一种基于微型同步相量测量单元（也叫做μPMU或者微同步相量）的新方法对主动配电网的故障进行定位。该方法运用单端μPMU采集的电压电流信息,查找故障线路,得到候选故障点并计算其故障距离。并根据两端μPMU测量电压和故障电压之间的相位关系,排除伪故障点,确定故障点位置。仿真结果表明,在主动配电网下,该定位方法具有较高的定位精度,仅需在线路的两端配置μPMU即可满足对不同类型故障进行准确地定位。在高渗透率DG和高阻故障的情况下,该定位方法依然可以准确地对故障进行定位。     

广域测量系统故障定位新方法

基于全球定位系统（GPS）的相量测量单元（PMU）的出现,使得在电力系统中应用广域电流差动保护成为可能。提出了一种新型的故障定位方法,即采用聚类分析最短距离法,并结合图论工具,对系统进行归类并划分保护区域。计算保护区内的电流之和,并据此判断保护区内是否存在故障。若保护区内存在故障,则通过逐渐减小阀值,将该保护区划分成若干子保护区,并重复以上步骤,最终锁定故障区域。     

小波包能量熵和改进的LSSVM在风力机轴承故障诊断中的应用

针对极端复杂工况下风力机轴承运行状态监测中的故障诊断问题,提出一种基于小波包能量熵故障特征提取并结合鲸鱼算法(WOA)优化最小二乘支持向量机(LSSVM)进行故障分类识别的风力机轴承故障诊断方法。通过小波包分解提取各频带成分的能量熵值构建故障特征集,同时针对LSSVM参数的选取依赖人工选择的盲目性问题,采用鲸鱼优化算法寻找LSSVM中最优的2个关键参数正则化参数和核函数参数,以此提高故障诊断模型的分类精度。通过不同工况下的试验数据集测试,实现了对不同故障状态特征参数的准确分类。结果表明,所提方法诊断结果优于遗传算法(GA)和粒子群算法(PSO)分别优化的LSSVM.远优于传统的LSSVM算法。     

基于多层次的负荷优化分配方法研究

目前,节能减排已成为电力行业面临的迫切任务。在发电厂,区域电网中实施负荷的优化调度意义重大。针对这种形势,提出了基于单机故障、发电企业、区域电网的三个不同层次的负荷优化分配方案。并且,阐述了不同层次负荷优化方案研究方法及发展现状,引入了环境外部成本的概念。最后,对区域负荷优化分配方案的前景进行了展望。     

适用于核动力设备故障诊断的改进粒子群优化算法

提出一种基于改进粒子群优化(IPSO)算法的核动力设备故障诊断方法.利用已知核动力设备故障征兆集合,选用概率因果模型求解具有最大后验概率的故障集合;在传统粒子群优化(PSO)算法的基础上,利用佳点集原理对PSO算法进行初始化,优化了粒子群的初始化范围;借助自适应调整的惯性权重法,避免PSO算法未成熟收敛,加快了收敛速度.最后通过算例证明该方法的有效性.结果表明:基于改进粒子群优化算法的概率因果模型不受故障样本的限制,具有较好的通用性,且模型故障诊断精度较高、寻优速度快.     

基于故障过流度的配电网故障区域定位新矩阵算法

针对现有配电网故障区域定位算法存在的问题,提出一种基于故障过流度的配电网故障区域定位新矩阵算法。该算法通过网络描述矩阵和故障信息矩阵计算比较故障时各区段的故障过流度,判定发生故障的区段,实现对配电网的故障定位。算例分析表明,该算法有效,适用于单电源、多电源和馈线末端故障等各种情况。     

基于CNN优化的蓄热式电锅炉供暖系统容错控制方法

为了提升容错控制效果,降低运行成本,保证供暖系统供热稳定性,研究基于CNN优化的蓄热式电锅炉供暖系统容错控制方法.优化CNN中不同尺度卷积核卷积输入的供暖系统信号,利用lesky-relu激活函数提取卷积信号内的故障信息,得到故障特征图,实现蓄热式电锅炉供暖故障检测;依据内模原理,结合故障检测结果,设计故障补偿器,降低...     

Optimal redundant placement of PMUs in Indian power grid — northern,eastern and north-eastern regions

Effective utilization of renewable energy sources and efficient management of electric energy are essential for any developing countries like India. This can be envisioned through the implementation of concepts of smart grid (SG). One of the key requisites for SG implementation is that the grid should be completely observable. Renovation of conventional Indian power grid to a SG necessitates incorporation of the phasor measurement units (PMUs) in the present power grid measurement and monitoring system. Since the cost of PMU is high and any bus containing a PMU makes the neighboring connected buses observable, optimal placement of PMUs is very important for complete observability of the grid. This paper proposes optimal redundant geographical locations in the northern, eastern and north-eastern regions of Indian power grid for PMU placement. The PMUs installed in these geographical locations will make the grid completely observable and maintain the observability under the conditions of failure of some PMUs or branch outages. Integer linear programming has been used for finding the optimal PMU locations. The results proposed in this paper can be a stepping stone for revamping the Indian power grid to a SG ensuring complete observability during different contingency conditions.     

Phasing in the Technology

P september/october 2008 ieee power & energy magazine 25 Phasor measurements were introduced as a specialized power system measurement in 1986. Following a paper published in 1983 describing the technique, Virginia Tech produced prototype phasor measurement units (PMU s) that were supplied to American Electric Power (AE P) and the Bonneville Power Administration (BPA). These units were tested and used by these utilities for several years before the first commercial unit, the Macrodyne 1690, was introduced in 1991. Using the original PMU s, AE P and BPA built phasor measurement systems that only provided recorded data for analysis with basic plotting tools. BPA redesigned the measurement system in 1997 into a true real-time, widearea measurement system (Figure 1) using commercial PMU s and a custom phasor data concentrator (PDC ). Since then, many phasor data systems have been developed and deployed throughout the world. Many more PMU models have become available with a range of options. Several variations of PDC units have been produced, and many applications are available for analysis of recorded phasor data as well as real-time display and alarming. This article examines the current phasor measurement systems in North America.     

故障限流器在新能源并网中最佳安装位置和参数配置研究

当电力系统发生短路故障时,为了防止并网容量逐年增加的分布式电源提供过大的短路电流,该文提出安装故障限流器(FCL)来限制短路电流突增的问题.FCL的安装主要考虑安装位置和参数配置,利用PSCAD/EMTDC搭建典型仿真模型,分别进行有/无新能源情况下,不同故障点的短路电流变化情况,对比得出新能源并网端变化最大,即FCL...     

Pragmatic multi-stage simulated annealing for optimal placement of synchrophasor measurement units in smart power grids

Conventional power grids across the globe are reforming to smart power grids with cutting edge technologies in real time monitoring and control methods. Advanced real time monitoring is facilitated by incorporating synchrophasor measurement units such as phasor measurement units (PMUs) to the power grid monitoring system. Several physical and economic constraints limit the deployment of PMUs in smart power grids. This paper proposes a pragmatic multi-stage simulated annealing (PMSSA) methodology for finding the optimal locations in the smart power grid for installing PMUs in conjunction with existing conventional measurement units (CMUs) to achieve a complete observability of the grid. The proposed PMSSA is much faster than the conventional simulated annealing (SA) approach as it utilizes controlled uphill and downhill movements during various stages of optimization. Moreover, the method of integrating practical phasor measurement unit (PMU) placement conditions like PMU channel limits and redundant placement can be easily handled. The efficacy of the proposed methodology has been validated through simulation studies in IEEE standard bus systems and practical regional Indian power grids.     

Subsynchronous oscillation monitoring and alarm method based on phasor measurements

Owing to the large-scale grid connection of new energy sources, several installed power electronic devices introduce sub-/supersynchronous inter-harmonics into power signals, resulting in the frequent occurrence of subsynchronous oscillations (SSOs). The SSOs may cause significant harm to generator sets and power systems; thus, online monitoring and accurate alarms for power systems are crucial for their safe and stable operation. Phasor measurement units (PMUs) can realize the dynamic real-time monitoring of power systems. Based on PMU phasor measurements, this study proposes a method for SSO online monitoring and alarm implementation for the main station of a PMU. First, fast Fourier transform frequency spectrum analysis is performed on PMU current phasor amplitude data to obtain subsynchronous frequency components. Second, the support vector machine learning algorithm is trained to obtain the amplitude threshold and subsequently filter out safe components and retain harmful ones. Finally, the adaptive duration threshold is determined according to frequency susceptibility, amplitude attenuation, and energy accumulation to decide whether to transmit an alarm signal. Experiments based on field data verify the effectiveness of the proposed method.     

Optimal placement of PMUs for the smart grid implementation in Indian power grid—A case study

Efficient utilization of energy resources is essential for a developing country like India. The concept of smart grid (SG) can provide a highly reliable power system with optimized utilization of available resources. The present Indian power grid requires revolutionary changes to meet the growing demands and to make the grid smarter and reliable. One of the important requirements for SG is the instantaneous monitoring of the voltage, current and power flows at all buses in the grid. The traditional monitoring system cannot satisfy this requirement since they are based on nonlinear power flow equations. Synchro-phasor-measurement devices like phasor measurement units (PMUs) can measure the phasor values of voltages at installed buses. Consequently, the currents passing through all branches connected to that bus can be computed. Since the voltage phasor values at the neighboring buses of a bus containing the PMU can be estimated using Ohm’s law, it is redundant to install PMUs at all the buses in a power grid for its complete observability. This paper proposes the optimal geographical locations for the PMUs in southern region Indian power grid for the implementation of SG, using Integer Linear Programming. The proposed optimal geographical locations for PMU placement can be a stepping stone for the implementation of SG in India.     

基于PMU量测的线路参数辨识算法

利用PMU量测数据具有严格时间同步、均匀发送的特点,基于PI型等值电路模型,提出一种新的线路参数辨识方法。该方法以线路两端测量的电压和电流相量为基础,利用最小二乘算法实现线路参数的最小偏差辨识,理论分析和实际算例表明了该方法的可行性。对影响辨识精度的主要误差源进行了分析,并给出了一种实用的坏数据剔除方法,可进一步提高数据辨识的精度;亦对如何利用线路量测的残差分析结果指导状态估计中的权重系数设置进行了详细讨论。与传统方法相比,基于PMU量测的参数辨识方法具有灵活、简便、可重复和连续执行的优点,具有较高的实用价值。     

相量测量装置在750 kV变电站的应用

对在西北电网750 kV变电站装设的PMU装置应用和运行情况进行了阐述。西北电网PMU相量测量装置具备实时监测、动态数据实时记录和实时通信三大功能,且三者互不干扰、互不影响。列举了该装置在满负荷试验和电网故障时的应用实例,对运行中发现的端子接线问题、程序参数设计问题进行了具体分析。通过对广域相量测量的总结说明在750 kV电网范围内推广开展的重要性。