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High impedance fault detection in distribution network based on S-transform and average singular entropy 被引量:2
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作者 Xiaofeng Zeng Wei Gao Gengjie Yang 《Global Energy Interconnection》 EI CAS CSCD 2023年第1期64-80,共17页
When a high impedance fault(HIF)occurs in a distribution network,the detection efficiency of traditional protection devices is strongly limited by the weak fault information.In this study,a method based on S-transform... When a high impedance fault(HIF)occurs in a distribution network,the detection efficiency of traditional protection devices is strongly limited by the weak fault information.In this study,a method based on S-transform(ST)and average singular entropy(ASE)is proposed to identify HIFs.First,a wavelet packet transform(WPT)was applied to extract the feature frequency band.Thereafter,the ST was investigated in each half cycle.Afterwards,the obtained time-frequency matrix was denoised by singular value decomposition(SVD),followed by the calculation of the ASE index.Finally,an appropriate threshold was selected to detect the HIFs.The advantages of this method are the ability of fine band division,adaptive time-frequency transformation,and quantitative expression of signal complexity.The performance of the proposed method was verified by simulated and field data,and further analysis revealed that it could still achieve good results under different conditions. 展开更多
关键词 High impedance fault(hif) Wavelet packet transform(WPT) S-transform(ST) Singular entropy(SE)
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基于改进LSTM的小电流系统HIF诊断方法
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作者 刘勇 吴伟丽 +1 位作者 刘俊 陈保香 《电力系统装备》 2023年第7期35-37,共3页
文章针对小电流系统弧光高阻接地故障(High Impedance﹣Grounding Fault,HIF)信号微弱、监测样本数据偏少造成的诊断困难问题,提出一种基于改进LSTM的小电流系统弧光高阻接地故障辨识方法。针对电弧信号具有的零歇特征,采用卷积神经网络... 文章针对小电流系统弧光高阻接地故障(High Impedance﹣Grounding Fault,HIF)信号微弱、监测样本数据偏少造成的诊断困难问题,提出一种基于改进LSTM的小电流系统弧光高阻接地故障辨识方法。针对电弧信号具有的零歇特征,采用卷积神经网络(CNN)对零歇局部特征加以提取,并利用LSTM进行全局特征提取,以最大限度地保留和凸显弧光接地故障信号特征,实现对小电流系统弧光高阻接地故障的准确辨识。并利用仿真数据和实测数据对方法加以验证,表明了方法的可行性和优越性。 展开更多
关键词 CNN﹣LSTM hif 故障诊断
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一种基于经验模态分解和局部极大值点数的配电网高阻接地故障检测方法
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作者 唐钧益 曾肖枫 高伟 《电气技术》 2024年第6期14-23,共10页
配电网高阻接地故障(HIF)因故障特征微弱而难以被常规装置检测到,容易引发过电压、火灾和人身触电等安全问题。本文提出一种将时频分解和阈值判断结合的HIF识别方法。首先,利用经验模态分解(EMD)对零序电流进行处理;然后,选取第二个固... 配电网高阻接地故障(HIF)因故障特征微弱而难以被常规装置检测到,容易引发过电压、火灾和人身触电等安全问题。本文提出一种将时频分解和阈值判断结合的HIF识别方法。首先,利用经验模态分解(EMD)对零序电流进行处理;然后,选取第二个固有模态分量(IMF)作为特征分量并进行高斯滤波;最后,统计特征分量的局部极大值点的个数来判断是否发生HIF。利用PSCAD/EMTDC软件搭建10kV配电网模型进行算法验证。仿真结果表明,所提方法能够以较高的准确率将HIF和一些常见的干扰事件区分开,并且在发生噪声干扰、采样率变化、系统中性点接地方式改变及系统网络结构改变的情况下,均表现出较好的适应性。 展开更多
关键词 配电网 高阻接地故障(hif) 经验模态分解(EMD) 局部极大值点数
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基于信号包络与希尔伯特边际谱的高阻接地故障检测方法
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作者 李宽宏 林金树 +2 位作者 江捷 朱少芬 肖中波 《电气技术》 2024年第6期39-46,55,共9页
配电网高阻接地故障(HIF)信号具有失真性和随机性,故障特征微弱,难以被有效检测。为此,本文提出一种基于信号包络(SE)和希尔伯特边际谱(HMS)的HIF诊断方法。该方法对长时间尺度的零序电压提取SE和HMS,分别代表HIF的失真性和随机性特征... 配电网高阻接地故障(HIF)信号具有失真性和随机性,故障特征微弱,难以被有效检测。为此,本文提出一种基于信号包络(SE)和希尔伯特边际谱(HMS)的HIF诊断方法。该方法对长时间尺度的零序电压提取SE和HMS,分别代表HIF的失真性和随机性特征。将这些特征转化为图像,利用ResNet18实现对HIF的检测。该方法的有效性已在10kV真型试验中得到验证,试验结果表明,该方法的HIF检测精度明显优于对比方法,尤其是在谐振接地系统中。 展开更多
关键词 谐振接地系统 高阻接地故障(hif) 故障检测 深度学习 信号包络(SE) 希尔伯特边际谱(HMS)
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High-impedance Fault Detection Method Based on Feature Extraction and Synchronous Data Divergence Discrimination in Distribution Networks
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作者 Yang Liu Yanlei Zhao +3 位作者 Lei Wang Chen Fang Bangpeng Xie Laixi Cui 《Journal of Modern Power Systems and Clean Energy》 SCIE EI CSCD 2023年第4期1235-1246,共12页
High-impedance faults(HIFs)in distribution networks may result in fires or electric shocks.However,considerable difficulties exist in HIF detection due to low-resolution measurements and the considerably weaker time-f... High-impedance faults(HIFs)in distribution networks may result in fires or electric shocks.However,considerable difficulties exist in HIF detection due to low-resolution measurements and the considerably weaker time-frequency characteristics.This paper presents a novel HIF detection method using synchronized current information.The method consists of two stages.In the first stage,joint key characteristics of the system are extracted with the minimal system prior knowledge to identify the global optimal micro-phase measurement unit(μPMU)placement.In the second stage,the HIF is detected through a multivariate Jensen-Shannon divergence similarity measurement using high-resolution time-synchronized data inμPMUs in a high-noise environment.l2,1 principal component analysis(PCA),i.e.,PCA based on the l2,1 norm,is applied to an extracted system state and fault features derived from different resolution data in both stages.An economic observability index and HIF criteria are employed to evaluate the performance of placement method and to identify HIFs.Simulation results show that the method can reliably detect HIFs with reasonable detection accuracy in noisy environments. 展开更多
关键词 high-impedance fault micro-phase measurement unit fault detection distribution network optimal placement
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Single-phase-to-ground fault protection based on zero-sequence current ratio coefficient for low-resistance grounding distribution network 被引量:4
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作者 Jianrui Li Yongli Li +1 位作者 Yonghuan Wang Jinzhao Song 《Global Energy Interconnection》 EI CAS CSCD 2021年第6期564-575,共12页
Definite-time zero-sequence over-current protection is presently used in systems whose neutral point is grounded by a low resistance(low-resistance grounding systems).These systems frequently malfunction owing to thei... Definite-time zero-sequence over-current protection is presently used in systems whose neutral point is grounded by a low resistance(low-resistance grounding systems).These systems frequently malfunction owing to their high settings of the action value when a high-impedance grounding fault occurs.In this study,the relationship between the zero-sequence currents of each feeder and the neutral branch was analyzed.Then,a grounding protection method was proposed on the basis of the zero-sequence current ratio coefficient.It is defined as the ratio of the zero-sequence current of the feeder to that of the neutral branch.Nonetheless,both zero-sequence voltage and zero-sequence current are affected by the transition resistance,The influence of transition resistance can be eliminated by calculating this coefficient.Therefore,a method based on the zero-sequence current ratio coefficient was proposed considering the significant difference between the faulty feeder and healthy feeder.Furthermore,unbalanced current can be prevented by setting the starting current.PSCAD simulation results reveal that the proposed method shows high reliability and sensitivity when a high-resistance grounding fault occurs. 展开更多
关键词 Low-resistance grounding system high-impedance grounding fault Grounding protection Zero-sequence current ratio coefficient
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智能配电网建设中的继电保护问题 讲座四 配电网保护新技术 被引量:8
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作者 徐丙垠 李天友 薛永端 《供用电》 2012年第4期17-25,共9页
探讨广域保护的基本概念及其在配电网中的适用性,介绍了利用相邻保护启动信号闭锁的广域电流保护与用于闭环运行环网的广域电流差动保护。分析了配电网中高阻故障的特征,介绍了基于零序电流、模式识别、三次谐波电流、断线电压监测的几... 探讨广域保护的基本概念及其在配电网中的适用性,介绍了利用相邻保护启动信号闭锁的广域电流保护与用于闭环运行环网的广域电流差动保护。分析了配电网中高阻故障的特征,介绍了基于零序电流、模式识别、三次谐波电流、断线电压监测的几种主要的高阻故障保护方法,并分析了各种方法的优缺点与适用场合。最后,介绍了一种脉冲重合闸技术,采用特殊设计的开关,通过在电压峰值时重合、在第一次电流过零时分闸,以避免重合到故障时产生的短路电流危害。 展开更多
关键词 智能电网 配电网 继电保护 广域保护 高阻故障 脉冲重合闸
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基于行波全波形能量分布特征的高阻接地故障检测方法 被引量:4
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作者 邓丰 徐帆 +4 位作者 冯思旭 曾祥君 黄懿菲 曾哲 张振 《中国电机工程学报》 EI CSCD 北大核心 2022年第22期8177-8189,共13页
配电网发生高阻接地故障(high impedance fault,HIF)时,故障特征微弱且易与空载线路投切,负荷投切,电容投切等正常暂态扰动混淆,检测困难。针对上述问题,该文定性和定量分析HIF与正常暂态扰动信号在时频域能量分布上的差异,发现前者在... 配电网发生高阻接地故障(high impedance fault,HIF)时,故障特征微弱且易与空载线路投切,负荷投切,电容投切等正常暂态扰动混淆,检测困难。针对上述问题,该文定性和定量分析HIF与正常暂态扰动信号在时频域能量分布上的差异,发现前者在时频域上能量分布相对均匀,稀疏程度小,后者在时频域上能量分布相对集中,稀疏程度大。据此,提出一种基于行波全波形能量分布特征的HIF灵敏、可靠检测方法。首先,利用连续小波变换时频局部化特性,将行波波形的时频域故障信息可视化呈现,得到行波全波形,基于此,构建时频能谱矩阵;通过行波全波形能量突变构造启动判据;引入稀疏因子量化时频能谱矩阵的能量分布均匀程度,构造HIF检测判据,可靠辨识HIF和正常暂态扰动。仿真分析及现场实验结果表明:该方法可以灵敏、可靠检测高达5kΩ的配电网HIF。 展开更多
关键词 配电网 高阻接地故障 行波全波形 小波能量熵 稀疏因子
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基于HHT的微电网差分能量保护策略 被引量:7
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作者 田书 孙永超 周令 《电力系统保护与控制》 EI CSCD 北大核心 2018年第11期55-61,共7页
针对微电网双向潮流和并网/孤岛运行时故障电流差异大的特点,在微电网差动保护的基础上,提出了基于HHT变换的差分能量保护新方法。对故障线路两端电流进行时-频变换(HHT变换)获得Hilbert谱,并计算谱能量,利用差分能量是否超出阈值判断... 针对微电网双向潮流和并网/孤岛运行时故障电流差异大的特点,在微电网差动保护的基础上,提出了基于HHT变换的差分能量保护新方法。对故障线路两端电流进行时-频变换(HHT变换)获得Hilbert谱,并计算谱能量,利用差分能量是否超出阈值判断是区内故障还是区外故障,且不同故障类型阈值无需改变。在PSCAD中搭建10 kV微电网模型并在Matlab中进行算例验证。大量仿真表明此方法能够可靠检测出并网和孤岛两种运行状态下的各种故障,而且有效解决了高阻抗故障(HIF)保护失效问题。 展开更多
关键词 微电网保护 HILBERT-HUANG变换 谱能量 高阻抗故障(hif) 自适应
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输电线路高阻接地故障的建模研究 被引量:4
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作者 陈承 李春明 闫旭 《电气技术》 2014年第9期32-35,40,共5页
高阻接地故障(HIF)检测方法的研究难点在于其模型精确度的问题。为了解决该问题,本文定义了HIF特征及性质,并针对传统改进的伊曼纽尔模型和电弧模型反映HIF特征的不足,基于实测数据和物理现象,通过数值计算等方法建立了一个新模型。该... 高阻接地故障(HIF)检测方法的研究难点在于其模型精确度的问题。为了解决该问题,本文定义了HIF特征及性质,并针对传统改进的伊曼纽尔模型和电弧模型反映HIF特征的不足,基于实测数据和物理现象,通过数值计算等方法建立了一个新模型。该模型模块简单、仿真速度快、参数容易调整。在EMTP环境下进行仿真验证,结果表明,HIF特征明显,并分析了模型误差来源。 展开更多
关键词 高阻故障 数值计算 hif模型 EMTP仿真
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基于变分模态分解与图信号指标的配电网高阻接地故障识别算法 被引量:10
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作者 肖启明 郭谋发 《电气技术》 2021年第5期50-55,共6页
为有效检测配电网高阻接地故障(HIF)的发生,本文结合变分模态分解与图信号指标,提出一种全新的HIF识别算法。首先,利用变分模态(VMD)分解得到故障暂态零序电流的多个本征模态分量;其次,根据峭度准则选取对故障暂态突变量最敏感的模态分... 为有效检测配电网高阻接地故障(HIF)的发生,本文结合变分模态分解与图信号指标,提出一种全新的HIF识别算法。首先,利用变分模态(VMD)分解得到故障暂态零序电流的多个本征模态分量;其次,根据峭度准则选取对故障暂态突变量最敏感的模态分量,进而计算该模态分量的图信号指标作为故障指标;最后,通过随机森林分类器对故障特征进行重要性评估与分类,达到识别HIF的目的。在PSCAD/EMTDC进行仿真验证,结果表明所提算法能够有效区分高阻接地故障与负荷投切(LC)和电容器投切(CS)。 展开更多
关键词 配电网 高阻接地故障(hif) 变分模态分解(VMD) 图信号指标
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综合谐波算法的小电阻接地配电网高阻比率制动保护 被引量:2
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作者 倪江 孙昕炜 +2 位作者 熊晓曼 任昊 杨宇玄 《综合智慧能源》 CAS 2022年第1期80-86,共7页
中性点经小电阻接地的配电网发生高阻接地故障,因故障电流微弱,传统过流保护装置容易拒动,而已有的高阻接地故障检测算法因复杂的故障特征应用受到一定限制。分析高阻接地故障电流特征发现,线路零序电流存在谐波特性且与变压器中性点零... 中性点经小电阻接地的配电网发生高阻接地故障,因故障电流微弱,传统过流保护装置容易拒动,而已有的高阻接地故障检测算法因复杂的故障特征应用受到一定限制。分析高阻接地故障电流特征发现,线路零序电流存在谐波特性且与变压器中性点零序电流大小成正比的特征,据此提出综合零序电流谐波算法的比率制动保护。其原理是整定值根据中性点零序电流大小和线路零序电流三次谐波进行自适应调整;进一步设定保护判据及整定值,建立高阻接地故障模型。在典型小电阻接地配电网中对各种算法进行仿真测试,并对各种算法进行对比,仿真结果验证综合谐波算法的高阻比率制动保护兼顾了可靠性和灵敏性。 展开更多
关键词 小电阻接地配电网 高阻接地故障 谐波算法 比率制动保护 零序电流
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Expansion of the Decoupled Discreet-Time Jacobian Eigenvalue Approximation for Model-Free Analysis of PMU Data
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作者 Sean D. Kantra Elham B. Makram 《Journal of Power and Energy Engineering》 2017年第6期14-35,共22页
This paper proposes an extension of the algorithm in [1], as well as utilization of the wavelet transform in event detection, including High Impedance Fault (HIF). Techniques to analyze the abundant data of PMUs quick... This paper proposes an extension of the algorithm in [1], as well as utilization of the wavelet transform in event detection, including High Impedance Fault (HIF). Techniques to analyze the abundant data of PMUs quickly and effectively are paramount to increasing response time to events and unstable parameters. With the amount of data PMUs output, unstable parameters, tie line oscillations, and HIFs are often overlooked in the bulk of the data. This paper explores model-free techniques to attain stability information and determine events in real-time. When full system connectivity is unknown, many traditional methods requiring other bus measurements can be impossible or computationally extensive to apply. The traditional method of interest is analyzing the power flow Jacobian for singularities and system weak points, attained by applying singular value decomposition. This paper further develops upon the approach in [1] to expand the Discrete-Time Jacobian Eigenvalue Approximation (DDJEA), giving values to significant off-diagonal terms while establishing a generalized connectivity between correlated buses. Statistical linear models are applied over large data sets to prove significance to each term. Then the off diagonal terms are given time-varying weights to account for changes in topology or sensitivity to events using a reduced system model. The results of this novel method are compared to the present errors of the previous publication in order to quantify the degree of improvement that this novel method imposes. The effective bus eigenvalues are briefly compared to Prony analysis to check similarities. An additional application for biorthogonal wavelets is also introduced to detect event types, including the HIF, for PMU data. 展开更多
关键词 SYNCHROPHASOR PMU openPDC Power Flow JACOBIAN Decoupled Discrete-Time JACOBIAN Approximation (DDJEA) SINGULAR Value Decomposition (SVD) High Impedance fault (hif) Discrete Wavelet Transform (DWT)
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基于DBN的配电网高阻接地故障识别 被引量:1
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作者 刘炳南 《电器与能效管理技术》 2020年第8期68-74,共7页
配电网运行时受现实条件的影响,接触到电阻大的物质从而发生高阻接地故障(HIF)时,故障电流微弱,波形特征不明显,常规保护装置无法准确切除故障。利用希尔伯特-黄变换(HHT)带通滤波对母线三相电压和零序电压进行处理,构造分块时频能量谱... 配电网运行时受现实条件的影响,接触到电阻大的物质从而发生高阻接地故障(HIF)时,故障电流微弱,波形特征不明显,常规保护装置无法准确切除故障。利用希尔伯特-黄变换(HHT)带通滤波对母线三相电压和零序电压进行处理,构造分块时频能量谱,输入到深度置信网络进行训练和分类识别。最后,通过搭建的仿真模型,验证算法具有较高的准确率。 展开更多
关键词 配电网 高阻接地故障 HHT带通滤波 深度置信网络
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Faulty Phase Identification for Transmission Line with Metal Oxide Varistor-protected Series Compensator
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作者 Mohammed Hussien Hassan Musa Ling Fu +1 位作者 Zhengyou He Yumin Lei 《Journal of Modern Power Systems and Clean Energy》 SCIE EI CSCD 2021年第1期85-93,共9页
The nonlinear operation of metal oxide varistor(MOV)-protected series compensator in transmission lines introduces complications into fault detection approaches. The accuracy of a conventional fault detection schemes ... The nonlinear operation of metal oxide varistor(MOV)-protected series compensator in transmission lines introduces complications into fault detection approaches. The accuracy of a conventional fault detection schemes is adversely affected by continuous change of the system impedance and load current at the point of a series compensation unit. Thus, this study suggests a method for detecting the faulted phase in MOV-protected series-compensated transmission lines. Primarily, the fault feature is identified using the covariance coefficients of the current samples during the fault period and the current samples during the pre-fault period. Furthermore, a convenience fault detection index is established by applying the cumulative sum technique. Extensive validation through different fault circumstances is accomplished, including different fault positions,resistances, and inception times. The experimental results show that the proposed method performs well with high resistance or impedance faults, faults in noisy conditions, and close-in and far-end faults. The proposed method is simple and efficient for faulty phase detection in MOV-protected series-compensated transmission lines. 展开更多
关键词 Cumulative approach covariance coefficient high-impedance fault response time
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基于行波全景故障特征自辨识的高阻接地故障检测方法 被引量:3
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作者 胡一鸣 史鸿飞 +4 位作者 张玉龙 王钰清 刘嘉庆 袁军 邓丰 《供用电》 2023年第4期39-46,54,共9页
受故障信号微弱、配电网存在噪声干扰等因素的影响,高阻接地故障情况下行波波头提取和检测困难,导致基于行波信号的高阻故障检测方法可靠性不高。针对上述问题,提出一种基于行波全景故障特征自辨识的高阻接地故障检测方法。首先,借助行... 受故障信号微弱、配电网存在噪声干扰等因素的影响,高阻接地故障情况下行波波头提取和检测困难,导致基于行波信号的高阻故障检测方法可靠性不高。针对上述问题,提出一种基于行波全景故障特征自辨识的高阻接地故障检测方法。首先,借助行波全景波形对高阻接地故障与正常暂态扰动电压行波信号的时-频差异性进行分析;然后,搭建卷积注意力模块-卷积神经网络(convolutional block attention module-convolution neural network,CBAM-CNN)模型,使其较传统的卷积神经网络(conrolution neral network,CNN)模型更具抗干扰能力,将行波全景波形以灰度图形式输入卷积神经网络,实现对多维故障特征的提取与利用;最后,在PSCAD上搭建10 kV配电网模型进行各种故障条件下的仿真分析。结果表明:所提方法能够可靠检测高阻接地故障,抗噪性能良好,且不受故障位置、过渡电阻、初相角的影响,大大提高了基于行波信号的高阻接地故障检测方法的可靠性与灵敏性。 展开更多
关键词 配电网 高阻接地故障 行波全景波形 卷积神经网络 注意力机制
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配电网高阻接地故障保护技术及其发展 被引量:48
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作者 李天友 徐丙垠 薛永端 《供用电》 2018年第5期2-6,24,共6页
配电网中的人体触电、导线断线掉地、树闪等故障,接地电阻大,故障电流小,目前还缺少可靠的检测和保护手段。亟待研发高阻接地故障保护技术,以及时终止对触电者的伤害,消除导线坠地、树闪故障带来的触电和火灾隐患。文章主要介绍了配电... 配电网中的人体触电、导线断线掉地、树闪等故障,接地电阻大,故障电流小,目前还缺少可靠的检测和保护手段。亟待研发高阻接地故障保护技术,以及时终止对触电者的伤害,消除导线坠地、树闪故障带来的触电和火灾隐患。文章主要介绍了配电网高阻接地故障的主要类型、故障特征以及国内外高阻接地保护技术的研究与应用情况,希望能起到抛砖引玉的作用,推动配电网高阻保护技术的发展。 展开更多
关键词 配电网 高阻接地 故障特征 故障检测 保护
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