基于同步量测大数据的配网单相接地故障检测及定位方法

随着智能电网、配网自动化及广域量测系统的不断发展和完善,配电网产生了海量表征其运行状态的数据,为其单相接地故障检测定位提供了新的挑战。基于随机矩阵理论对配网大数据矩阵进行分析,首先用节点电压数据构造高维数据矩阵;然后用圆环律和平均谱半径进行故障检测;最后在检测到故障发生时,通过增广矩阵构造和配网结构相结合进行故障区域定位。仿真分析通过80节点配网模型的单相接地故障验证了所提方法的可行性。     

基于图论的电力系统PMU布点优化算法

基于最小支配集理论和电力系统线性量测模型．提出了可观测节点集合、WAMS可观测矩阵两个概念以及一种新的节点可观测性计算规则。以保证系统的完全可观测性和以系统图的最小支配集为搜索范围构成约束条件,以电力系统状态完全可观测和相量测量装置（PMU）配置数目最小为目标,形成了PMU配置优化问题。并应用禁忌搜索（TS）方法求解该问题,保证了全局寻优。最后采用IEEE14、30、57、118节点系统和新英格兰39节点系统对该方法进行了验证,仿真结果表明该方法的有效性和可行性。     

含有限PMU的主动配电网故障定位

对于含分布式电源(DG)的主动配电网,基于同步相量测量单元(PMU)的监测信息进行故障分析与处理,从而达到定位目的.首先采用拓扑优化法对PMU进行布点优化配置,同时将系统划分为不同区域.利用PMU监测所得实时潮流和电气量信息,基于功率增量方向原理可初步判断发生故障的区域;其次计算候选故障区域内各条区段发生不同类型故障时...     

考虑顾客满意度的电动汽车充电桩规划策略

基于模拟退火算法(SA),研究了电动汽车充电负荷对配网电压的影响及充电桩的最优分布问题。首先,分析了不同时刻、不同负荷渗透率和同一时刻同一渗透率3种情景下,电动汽车充电负荷对配网电压偏移量造成不同程度的影响;然后,根据排队理论,以顾客等待时间和充电桩利用率建立满意度函数,得到最优的充电桩数量;再以节点压降最小为目标函数,通过模拟退火算法得到充电桩的最优分布策略。通过IEEE33节点系统的计算结果证实,优化后的站址分布能够大大地减弱电动汽车充电负荷对配网系统节点电压的影响,为衔接配网规划与充电桩规划提供参考。     

基于潮流灵敏度的分布式电源优化配置方法

建立分布式电源优化配置的线性规划模型,该模型以改进的综合负荷指标和全网有功网损增量作为目标函数,采用节点有功功率和无功功率的增量为待优化变量,约束条件均为增量表达形式。结合系统潮流方程线性化后的灵敏度矩阵,目标函数和约束条件均可写为带优化变量的线性表达式,从而使得分布式电源优化配置问题转化为线性规划问题,该问题可采用内点法进行求解。通过典型33节点系统的不同场景对该方法进行测试,结果表明该方法可通过优化配置分布式电源提高系统电压水平并减少系统有功网损。     

基于WAMS的电网故障检测新方法

当出现大范围的停电事故时,保护系统自身的故障往往是导致灾难发生的原因之一。为了解决这个问题,提出一种利用PMU数据和母线阻抗矩阵（Zbus）以替代保护系统功能的独立故障检测方法。首先,根据提出的方法确定故障区域,然后确定故障线路。通过广域测量,故障位置随着线路的确定也就被估算出来。IEEE-118节点测试系统验证结果表明,该方法成功的检测出整个电网的故障线路以及故障线路中的故障位置     

基于三维可视图的地区电网电压凹陷评估

针对用电压凹陷矩阵来表示电网发生故障时产生的电压凹陷不够直观的问题,提出了在改进故障点法基础上用三维可视图来表示电压凹陷的方法,实现在多节点电网中可以直观地看出电网发生电压凹陷的节点及电压凹陷的深度。根据电压凹陷深度和故障距离的关系曲线对传输线分区,在每条传输线上设置有限个故障点,计算每个故障点上发生短路故障时,每个节点的电压凹陷深度,并通过每个故障点的故障概率分布来评估不同电压凹陷深度区间的凹陷频次,绘制电压凹陷的三维可视图。提出的方法应用于IEEE 30节点标准测试系统,验证了该方法的正确性和实用性。     

基于免疫算法的多目标无功补偿规划

应用雅可比矩阵最小特征值的右特征向量强相关和系统网损灵敏度的方法对系统的节点排序,选择无功补偿的最佳节点。提出了应用免疫算法的多目标无功补偿规划的算法求取节点的最优补偿容量。通过对IEEE 30节点系统计算并与其他算法比较,结果表明采用该优化规划的算法能有效地降低网损、提高系统电压稳定裕度。     

基于混合算法的配电网中电池储能的多目标优化配置研究

基于随机会约束规划理论,计及系统的不确定性因素提出配电网储能电站多目标选址定容模型。首先分析配电网的经济性和可靠性特征,接着基于随机机会约束规划建立储能电站的优化模型。采用二进制粒子群算法和改进粒子群算法的混合算法对模型进行求解。最后利用研究模型,结合IEEE 33标准节点系统建立配电网储能电站优化算例,对离网模式和并网模式2种模式进行仿真,对优化配置结果进行对比和分析。     

基于响应的电压稳定性评估和控制方法

提出了一种根据电力系统网络节点的实时信息评估系统电压稳定性的方法,当系统电压稳定裕度较低时,根据全网响应信息获得相应的切负荷量。该方法基于两节点电力系统等值网络,得到了系统电压稳定性的评估指标;从系统等值网络的等值过程出发,将节点等值负荷分成自身负荷和转移负荷两部分,推导了该节点电压稳定性的评估指标与有功负荷量之间的关系式,从而获得了该节点在满足一定电压稳定指标情况下的最大有功负荷量,进而得到该节点所需要的切负荷量。该方法首先利用电压稳定性的评估指标在线监视电网中各节点的电压稳定性,辨识危险节点;当系统电压稳定性不满足要求时,根据全网的电压、电流量等响应信息计算危险节点需要的减载量。在IEEE14节点系统和IEEE24节点系统下的仿真结果表明,所提方案能够保证电网的电压稳定性。     

Identification of critical nodes for cascade faults of grids based on electrical PageRank

In this paper, the electrical PageRank method is proposed to identify the critical nodes in a power grid considering cascading faults as well as directional weighting. This method can rapidly and accurately focus on the critical nodes in the power system. First, the proposed method simulates the scenario in a grid after a node is attacked by cascading faults. The load loss of the grid is calculated. Second, the electrical PageRank algorithm is proposed. The nodal importance of a grid is determined by considering cascading faults as well as directional weights. The electrical PageRank values of the system nodes are obtained based on the proposed electrical PageRank algorithm and ranked to identify the critical nodes in a grid. Finally, the effectiveness of the proposed method is verified using the IEEE39 node system. The proposed method is highly effective in preventing the occurrence of cascading faults in power systems.     

Current phase comparison pilot scheme for distributed generation networks protection

The trends of the actual distribution networks are moving toward a high penetration of distributed generation and power electronics converters. These technologies modify contribution-to-fault current magnitudes and raise concern about new protection parameters settings to accurately detect faults on distribution networks. This paper proposes a differential phase jump pilot scheme to detect faulted branches in distribution networks. The aim of the proposed scheme is to provide an efficient algorithm with functions of fault detection and isolation, which are part of the self-healing functions used for smart grids. The proposed scheme is based on the current phase jump measured in each node with fault inception. Then, by comparing the phase jump obtained with the prefault conditions and rate changes, it determines the fault direction enabling a trip signal to the corresponding nodes to isolate the branch under fault. A distribution network has been modeled in PSCAD/EMTDC program to verify the proposed algorithm, taking into account distributed generation provided by both wind turbines (doubly fed induction generator and permanent magnet generator with full converter) and solar photovoltaic installations. The behavior of the current phase jump has been studied for both generation and load nodes. This algorithm is not affected by the magnitude of current and voltage and has been tested varying fault location and resistance along the modeled distribution network.     

基于改进LFM算法的主动解列断面搜索方法

针对传统解列断面算法复杂度高的问题,提出一种基于改进LFM算法的解列断面搜索方式.首先,基于节点间电气联系和能量转移分布熵完成电网加权复杂网络建模;其次,基于主动解列断面约束条件,对LFM算法做适应性改良;最后,通过改进LFM算法得到解列断面,并在IEEE39节点系统中验证了算法有效性.仿真结果表明,改进LFM算法可充...     

交流侧接地方式对多端柔性直流配电网保护配置的影响

  [目的]  为了提高多端环形柔性直流配电网的供电可靠性,研究了交流侧不同接地方式下的故障特征及其对保护配置的影响。  [方法]  首先确定了两电平、模块化多电平等不同类型换流设备的交直流故障等效通路,从故障过压、过流水平及故障恢复等方面分析了不同接地方式下交直流不对称故障对保护配置的影响。随后从保护原理配置、定值整定、出口方式及配合原则等方面,给出了多端环形柔性直流配电网典型保护配置方案。最后,在PSCAD/EMTDC仿真软件下搭建了三端柔性直流配电网的电磁暂态模型。  [结果]  仿真结果表明:当交流侧采用高电阻接地方式时,通过合理的保护配置可提高交流不对称故障时系统的稳定性、实现直流不对称故障的零停电时间故障穿越。  [结论]  研究成果为多端柔性直流配电网的接地方式设计、保护配置研究提供了一定参考。     

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.     

基于马氏距离算法的配电网故障定位系统研究

为了满足智能配电网故障定位的实时性、可靠性、准确性等需求,提出了基于马氏距离算法的配电网故障定位系统。以IDT智能配电终端作为系统运行状态电气量实时采集核心模块,按F检验获得元件电气量变化显著性概率P值初判故障元件和故障类型后,通过马氏距离算法准确定位故障区域和故障元件,并采用IEEE9节点系统的三相短路故障对配电网故障定位系统进行测试分析。仿真结果表明,该系统能真实地反映配电网故障后故障区域和故障元件的电气量变化,可满足智能配电网在线故障定位需求。     

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.     

基于电气量判据的输电网故障诊断

以复杂电网故障诊断为目标,分析在发生多重故障且伴随不确定性因素的情况下的故障诊断流程,考虑保护和断路器拒动、误动可能性和告警信息误报、漏报等不确定性因素,对保护规则、动作状态和告警信息三者之间的关系进行解析,实现了实际动作状态和告警信息关系的解耦,并提出一种利用PMU电气量信息的电气量新判据,对常规解析模型增加约束,实现了故障诊断信息的冗余,极大地降低了误诊的可能性。