共查询到20条相似文献,搜索用时 31 毫秒
1.
Biman Kumar Saha Roy Ravi Sharma Ashok Kumar Pradhan Avinash Kumar Sinha 《电力部件与系统》2017,45(5):491-504
In this paper, a technique for identification of faulty line in a power system is proposed using phasor measurement units (PMUs). The identification is accomplished in two steps (i) detection of bus nearest to fault point and (ii) detection of faulty transmission line connected to that selected bus in step (i). The bus voltages and line currents associated with the non-PMU buses are computed from the available PMU data. Using maximum percentage deviation of bus voltages during fault, the bus nearest to the fault point is detected. With PMUs at all buses, faulty line identification can be accomplished by comparing the angles of positive sequence currents of all connected lines to the selected bus. However, with limited number of PMUs, phase angle comparison method becomes unreliable. Under such situation, comparison of fault voltage magnitudes (VMs) of the selected non-PMU bus computed from all connected routes is used to identify the faulty line. When the selected bus is a PMU bus, % deviation of VM of its connected buses is used to identify the other end of the faulty line. The effectiveness of the proposed technique is tested on IEEE 9-bus system and Northern Region of Electricity Board 391-bus, an Indian utility system. The usefulness of the faulty line identification in supplementing protection decision is also demonstrated for secured backup protection. 相似文献
2.
Remote monitoring system for real timedetection and classification of transmissionline faults in a power grid using PMUmeasurements
下载免费PDF全文
![点击此处可从《电力系统保护与控制》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Pathirikkat Gopakumar Balimidi Mallikajun Maddikara Jaya Bharata Reddy Dusmanta Kumar Mohanta 《电力系统保护与控制》2018,3(2):159-168
Remote monitoring of transmission lines of a power system is significant for improved reliability and stability during
fault conditions and protection system breakdowns. This paper proposes a smart backup monitoring system for detecting
and classifying the type of transmission line fault occurred in a power grid. In contradiction to conventional methods,
transmission line fault occurred at any locality within power grid can be identified and classified using measurements
from phasor measurement unit (PMU) at one of the generator buses. This minimal requirement makes the proposed
methodology ideal for providing backup protection. Spectral analysis of equivalent power factor angle (EPFA) variation
has been adopted for detecting the occurrence of fault that occurred anywhere in the grid. Classification of the type of
fault occurred is achieved from the spectral coefficients with the aid of artificial intelligence. The proposed system can
considerably assist system protection center (SPC) in fault localization and to restore the line at the earliest. Effectiveness
of proposed system has been validated using case studies conducted on standard power system networks. 相似文献
3.
《IEEJ Transactions on Electrical and Electronic Engineering》2017,12(5):702-709
This paper proposes a wide‐area backup protection technique for transmission lines using a limited number of synchronized phasor measurement units. A binary integral linear programming is used for optimal placement of phasor measurement units to achieve fault observability. The positive‐sequence voltage and current components are utilized for the detection and location of transmission lines faults. The proposed technique considers the randomness of faults on the transmission grid, different fault types, frequency fluctuations, synchronization and measurement errors, different fault inception angles, and different fault resistances, as well as various loading conditions. The proposed scheme is applied to the Western System Coordinating Council (WSCC) 9‐bus test system and the New England 39‐bus test system. Simulation results prove that the proposed protection scheme can detect and locate all transmission line faults correctly. © 2017 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc. 相似文献
4.
电网结构日益复杂,传统输电线路后备保护整定变得越来越困难.文中在间隔母线布置相量测量单元(PMU)策略下,先根据广域差动法确定故障区域,再估计出故障区域中未布置有PMU母线的电压和节点注入电流,推导出该区域节点电压故障分量方程,构造节点故障注入电流.分析故障发生前后故障线路两侧母线和正常母线的节点故障注入电流的变化特征,构造广域后备保护判据.基于IEEE 39节点系统的仿真结果验证了所提算法不受故障位置、类型和过渡电阻影响,在各种故障情景下均能检测出故障线路. 相似文献
5.
为了综合评估恶劣天气下输电线路故障与二次系统隐性故障导致的多重故障风险,提出了考虑一二次耦合多重故障的电力系统风险评估方法。首先,分析了气象灾害导致输电线路故障的特点,总结了一二次设备耦合多重故障的特点。其次,综合考虑输电线路及保护装置的失效概率,建立了一二次耦合多重故障模型。然后,应用拉丁超立方抽样实现初始故障集的快速生成,进而评估系统失负荷、节点电压越限、支路潮流越限等风险指标。最后,采用IEEE39节点系统对所提方法进行测试。研究结果表明:考虑一二次耦合的多重故障,系统面临的风险更为严重;使用拉丁超立方抽样,可兼顾不同气象分区内线路故障概率分布差异,提高计算效率;通过多维度风险指标排序,能够有效筛选灾害天气落区内影响电网风险的关键线路和母线,为电网风险防控和薄弱环节治理提供决策依据。 相似文献
6.
7.
随着智能电网建设的不断深入,配电网的智能化升级改造也步入正轨。同步相量测量技术不仅适用于输电系统,在实现配电网智能化方面也能发挥积极作用。基于美国FNET系统和国内WAMS Light系统,给出国内外配电网同步相量测量系统概念;从状态估计、故障定位、谐波估计、孤岛检测角度,介绍同步相量测量技术在配电网诊断方面的应用,并从微电网协调、电能质量控制、控制与保护角度论及它在配电网保护方面的应用。最终,针对配电网同步相量测量技术发展所遇问题,试着提出明确的解决思路。 相似文献
8.
当电力系统在功率低频振荡等动态情况下发生故障时,电力信号的幅值和频率往往表现出一定的动态特性,然而目前大部分同杆双回线故障定位方法并未考虑这一因素。为此提出了动态条件下基于线路参数修正的同杆双回线故障定位方法,新方法拓展了传统的静态信号模型,建立时变的信号模型使其能正确表示信号的动态特性,并加入基于同步相量测量单元(phasor measurement units,PMUs)的动态同步相量测量算法估计的信号相量值,从而可以在动态条件下精确修正线路参数,最后通过牛顿迭代算法得到准确的故障距离。应用PSCAD/EMTDC软件模拟各种工况对算法进行验证,仿真结果表明:与传统的算法相比,经过线路参数修正的方法在动态条件下具有较高的故障定位精度,并且不受故障位置、过渡电阻、故障类型和故障初始角的影响。 相似文献
9.
10.
对称双芯移相变压器(Phase Shifting Transformer, PST)作为潮流调控设备,能实现输电线路传输功率的调节。然而,PST接入线路后将改变线路阻抗分布、电压和电流信号,可能导致距离保护的误动或拒动。为了消除PST接入对常规距离保护造成的影响,根据PST对各序网故障分量的移相特性、PST序网等效阻抗以及接地、相间测量阻抗算法,推导出PST安装位置、PST移相角、故障位置均会对距离保护产生影响。基于距离保护受PST接入的影响机理,利用对称分量反变换、同步相量测量技术,提出了基于相角补偿和相量测量单元(Phasor Measurement Units, PMUs)的自适应距离保护。在此基础上,利用Matlab/Simulink搭建了PST的模型,并通过仿真验证了PST接入对距离保护影响机理推导的正确性以及所提出的自适应距离保护改进措施的有效性,为未来PST的深入研究和工程应用提供了理论支撑。 相似文献
11.
断路器和保护设备存在误动和拒动的可能性,不正确的动作会引入错误的故障信息干扰电网故障诊断。针对上述问题提出了一种基于广域故障录波数据和模糊C均值(FCM)聚类的电网故障诊断方法。对母线、输电线路和变压器这3种电网元件的故障录波数据进行挖掘分析,从中提取能够有效区分故障元件的特征;建立基于模糊C均值聚类的电网故障元件诊断模型。对故障后的元件进行聚类分析,并计算各元件的故障可信度,最终确定故障元件。新英格兰39节点系统的仿真和实际算例表明所提方法能够快速准确定位故障元件且不受故障类型和位置的影响。 相似文献
12.
13.
针对中性点不接地系统单相接地故障选线困难的问题,通过母线故障相接地故障转移与中性点接入小电阻的方式来增强故障信息从而选出故障线路.建立了故障转移阶段、并联电阻投入前后各个阶段的零序网络模型,分析了健全线路和故障线路各自的零序电流幅值的变化特征.在中性点小电阻投入、母线开关分闸前后各馈线零序电流幅值变化明显,健全线路零序... 相似文献
14.
15.
近年来,智能电网成为了各国学者的研究热点,并被认为是未来电网的发展趋势。而具有"时钟同步、空间广域"特点的广域测量系统,可以实时测量母线电压相量和发电机功角,实现了对电力系统的动态监视,被认为是构建智能电网的关键基础技术之一。将重点讨论近两年来我国基于广域测量技术的应用研究对实现智能电网可能存在的帮助,最后指出了需要进行深入研究的领域。 相似文献
16.
模块化多电平换流器型高压直流(MMC-HVDC)输电系统接入电网后将对交流系统短路电流产生影响,但目前交流保护整定计算通常忽略MMC-HVDC接入母线故障时模块化多电平换流器对短路电流的贡献。文中以交流保护整定计算为出发点,提出了MMC-HVDC系统简化分析原则。在分析MMC-HVDC系统控制特性的基础上,建立了适用于交流保护整定计算的MMC-HVDC等效模型,提出MMC-HVDC接入母线故障时可以将直流侧等效为一个正序电流源。研究了MMC-HVDC接入母线故障时不同故障点残压下MMC-HVDC直流侧响应特性,确定了等效电流源的幅值和相位,并进行了仿真验证。最后,提出了MMC-HVDC对交流保护整定计算影响的定量评估指标及其计算方法。 相似文献
17.
Maloperation of conventional relays is becoming prevalent due to ever increase in complexity of conventional
power grids. They are dominant during power system contingencies like power swing, load encroachment, voltage
instability, unbalanced loading, etc. In these situations, adaptive supervised wide-area backup protection (ASWABP)
plays a major role in enhancing the power system reliability. A balance between security and dependability of
protection is essential to maintain the reliability. This paper proposes multi-phasor measurement units (MPMU)
based ASWABP scheme that can function effectively during faults besides power system contingencies. MPMU is an
extended version of Phasor Measurement Unit (PMU). It is an intelligent electronic device which estimates the
synchronized predominant harmonic phasors (100Hz and 150Hz) along with the fundamental phasors (50Hz) of
three phase voltages and currents with high precision. The proposed ASWABP scheme can detect the fault, identify
the parent bus, determine the faulty branch and classify the faults using MPMU measurements at System Protection
Center (SPC). Based on these MPMU measurements (received at phasor data concentrator (PDC) at SPC) the
appropriate relays will be supervised to enhance the overall reliability of the power grid. Numerous case studies are
conducted on WSCC-9 bus and IEEE-14 bus systems to illustrate the security and dependability attributes of
proposed ASWABP scheme in MATLAB/Simulink environment. Also, comparative studies are performed with the
existing conventional distance protection (Mho relays) for corroborating the superiority of the proposed scheme
regarding security and dependability. Comparative studies have shown that the proposed scheme can be used as
adaptive supervised wide-area backup protection of conventional distance protection 相似文献
18.
19.
三侧同杆双回线互联的T型线路测距新方法 总被引:2,自引:1,他引:1
根据同杆双回线的特性建立了同杆双回线构成的T型线路的反序正序网络,提出了基于反序正序电流的故障测距方法。在双T型线路中,反序正序网络的电气量具有完整的T字型线路的正序电气量的特点,该特点可以用来故障测距。当双T线路发生故障时,由故障支路的母线处的电气量计算到故障点的反序正序电压等于由支接点T的等值反序正序电气量计算到故障点的反序正序电压,利用反序正序电压在故障点相等的等量关系可以进行精确故障测距。大量的EMTP仿真结果表明,所给出的故障测距方案是准确的,并且在由同杆双回线构成的T型线路故障测距中显示出较大的优势。该测距方法的精度不受故障支路、故障类型、系统运行方式、故障点过渡电阻等因素的影响。 相似文献
20.
TIAN Xin-liang CHENG Han-xiang School of Automation Guangdong University of Technology Guangzhou China 《西北电力技术》2008,(12)
阐述了快速、准确识别电网故障的必要性,提出了以3次B样条小波为分解工具,通过分解故障线路电流确定故障时刻及故障切除时刻的新方法。分析了利用二进小波确定故障线路的新思想,大量仿真论证了在各种故障模式下所提出算法的有效性和准确性。 相似文献