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基于SVM的改进二叉树输电线路故障分类器 被引量:7
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作者 王成江 马新明 +1 位作者 官云 戴迪 《电力系统保护与控制》 EI CSCD 北大核心 2010年第5期39-44,共6页
在研究二叉树多分类的基础上,结合输电线路故障的特点,考虑不同故障的优先级后,设计了基于SVM的改进二叉树输电线路故障分类器的模型,通过实验选择了最小二乘支持向量机LS-SVM算法和线性函数转换表达式的归一化算法,并用小样本模拟短路... 在研究二叉树多分类的基础上,结合输电线路故障的特点,考虑不同故障的优先级后,设计了基于SVM的改进二叉树输电线路故障分类器的模型,通过实验选择了最小二乘支持向量机LS-SVM算法和线性函数转换表达式的归一化算法,并用小样本模拟短路数据训练了分类器。测试结果表明,在各种输电线路故障情况下,设计的分类器都具有很高的分类正确率,尤其是对两相接地和不接地短路分类的效果显著,另外,该分类器的数据预处理过程简单,分类步骤少,可以实现输电线路故障的快速分类。 展开更多
关键词 SVM 二叉树 输电线路:故障 分类器
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Power swing and voltage collapse identification schemes for correct distance relay operation in power system 被引量:1
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作者 Ahmad F. Abidin Azah Mohamed Hussain Shareef 《Journal of Central South University》 SCIE EI CAS 2013年第4期988-1000,共13页
The new techniques were presented for preventing undesirable distance relay maloperation during voltage collapse and power swings in transmission grids. Initially, the work focused on the development of a fast detecti... The new techniques were presented for preventing undesirable distance relay maloperation during voltage collapse and power swings in transmission grids. Initially, the work focused on the development of a fast detection of voltage collapse and a three-phase fault at transmission lines by using under impedance fault detector (UIFD) and support vector machine (SVM). Likewise, an intelligent approach was developed to discriminate a fault, stable swing and unstable swing, for correct distance relay operation by using the S-transform and the probabilistic neural network (PNN). To illustrate the effectiveness of the proposed techniques, simulations were carried out on the IEEE 39-bus test system using the PSS/E and MATLAB software. 展开更多
关键词 under impedance fault detector distance relay FAULT voltage collapse
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Mechanisms governing the evolution of a long-lived northwest vortex that caused a series of disasters in Northwest China
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作者 Shuang-Long Jin Bo Wang +4 位作者 Shuang-Lei Feng Xiao-Lin Liu Zong-Peng Song Ju Hu Zheng Li 《Atmospheric and Oceanic Science Letters》 CSCD 2022年第2期19-25,共7页
The northwest vortex(NWV)is a type of mesoscale vortex that appears with a relatively high frequency in Northwest China.To further the understanding of the NWV’s evolution,in this study,the moisture and circulation b... The northwest vortex(NWV)is a type of mesoscale vortex that appears with a relatively high frequency in Northwest China.To further the understanding of the NWV’s evolution,in this study,the moisture and circulation budgets of a long-lived NWV(~132 h)that appeared in early August 2019 were calculated.This vortex induced a series of torrential rainfall events in Northwest China and Mongolia,which caused severe transmission line faults and urban waterlogging.Synoptic analyses indicate that the NWV was generated in a favorable background environment characterized by notable upper-level divergence and strong mid-level warm advection.The moisture budget shows that the East China Sea and Bohai Sea acted as the main moisture sources for the NWV-associated precipitation,and the water vapor was transported into the rainfall regions mainly by easterly and southeasterly winds.The circulation budget indicates that,during the developing stage,convergence-related vertical stretching was a dominant factor for the NWV’s development;whereas,the vortex’s displacement from regions with stronger cyclonic vorticity to those with weaker cyclonic vorticity mainly decelerated its development.In the decaying stage,divergence-related vertical shrinking and the net export of cyclonic vorticity due to the eddy flow’s transport resulted in the NWV’s dissipation. 展开更多
关键词 Northwest vortex Torrential rainfall Transmission line faults Moistrue budget Circulation budget
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Inter-Circuit Fault Location Algorithm for Two-Parallel Transmission Line
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作者 张庆超 李大勇 +1 位作者 李晖 屈洪鑫 《Transactions of Tianjin University》 EI CAS 2003年第3期189-192,共4页
A novel numerical algorithm of fault location estimation for four-line fault without ground connection involving phases from each of the parallel lines is presented in this paper. It is based on one-terminal voltage a... A novel numerical algorithm of fault location estimation for four-line fault without ground connection involving phases from each of the parallel lines is presented in this paper. It is based on one-terminal voltage and current data. The loop and nodal equations comparing faulted phase to non-faulted phase of two-parallel lines are introduced in the fault location estimation model, in which the source impedance of a remote end is not involved. The effects of load flow and fault resistance on the accuracy of fault location are effectively eliminated, therefore a precise algorithm of locating fault is derived. The algorithm is demonstrated by digital computer simulations. 展开更多
关键词 fault location estimation two-parallel line four-line fault
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Fault location of two-parallel transmission line for double phase-to-earth fault using one-terminal data
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作者 张庆超 段晖 +1 位作者 耿超 宋文南 《Journal of Zhejiang University Science》 CSCD 2003年第5期520-525,共6页
An accurate algorithm for fault location of double phase-to-earth fault on transmission line of direct ground neutral system is presented. The algorithm, which employs the faulted phase network and zero-sequence netwo... An accurate algorithm for fault location of double phase-to-earth fault on transmission line of direct ground neutral system is presented. The algorithm, which employs the faulted phase network and zero-sequence network as fault-location model in which the source impedance at the remote end is not involved, ef-fectively eliminates the effect of load flow and fault resistance on the accuracy of fault location. The algorithm achieves accurate location by measuring only one local end data and is used in a procedure that provides automatic determination of faulted types and phases, and does not require the engineer to specify them. Simulation results showed the effectiveness of the algorithm under the condition of double phase-to-earth fault. 展开更多
关键词 Fault location Transmission line Double phas e-to-earth fault
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A Transmission Line Fault Classification Approach by Support Vector Machines
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作者 A.M. Ibrahim A.Y. Abdelaziz S.F. Mekhamer M. Ramadan 《Journal of Energy and Power Engineering》 2011年第3期268-274,共7页
This paper presents an approach for shunt faults detection and classification in transmission line using Support Vector Machine (SVM). The paper compares between using three line post-fault current samples for one-h... This paper presents an approach for shunt faults detection and classification in transmission line using Support Vector Machine (SVM). The paper compares between using three line post-fault current samples for one-half cycle and one-fourth cycle from the inception of the fault as inputs for SVM. Two SVMs are used, first SVMabc is used for faulty phase detection and second SVMg is used for ground detection. SVMs with polynomial kernel with different degrees are used to obtain the best classification score. The classification test results show that the proposed method is accurate and reliable. 展开更多
关键词 Transmission line protection fault detection fault classification support vector machine.
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Fault Location in Transmission Lines Using BP Neural Network Trained with PSO Algorithm
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作者 Salah Sabry Daiboun Sahel Mohamed Boudour 《Journal of Energy and Power Engineering》 2013年第3期603-611,共9页
In modem protection relays, the accurate and fast fault location is an essential task for transmission line protection from the point of service restoration and reliability. The applications of neural networks based f... In modem protection relays, the accurate and fast fault location is an essential task for transmission line protection from the point of service restoration and reliability. The applications of neural networks based fault location techniques to transmission line are available in many papers. However, almost all the studies have so far employed the FNN (feed-forward neural network) trained with back-propagation algorithm (BPNN) which has a better structure and been widely used. But there are still many drawbacks if we simply use feed-forward neural network, such as slow training rate, easy to trap into local minimum point, and bad ability on global search. In this paper, feed-forward neural network trained by PSO (particle swarm optimization) algorithm is proposed for fault location scheme in 500 kV transmission system with distributed parameters presentation, The purpose is to simulate distance protection relay. The algorithm acts as classifier which requires phasor measurements data from one end of the transmission line and DFT (discrete Fourier transform). Extensive simulation studies carried out using MATLAB show that the proposed scheme has the ability to give a good estimation of fault location under various fault conditions. 展开更多
关键词 Transmission line protection fault location neural network BACK-PROPAGATION particle swarm.
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Novel Algorithm for Estimating the Distance of Open-Conductor Faults in HV Transmission Lines
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作者 Mahmoud Gilany Ahmed Al-Kandari Bahaa Hassan 《Journal of Energy and Power Engineering》 2012年第8期1301-1307,共7页
This paper presents an ANN (artificial neural networks)-based technique for improving the performance of distance relays against open-circuit faults in transmission networks. The technique utilizes the small capacit... This paper presents an ANN (artificial neural networks)-based technique for improving the performance of distance relays against open-circuit faults in transmission networks. The technique utilizes the small capacitive current measured in the open-phase plus the currents in the two healthy phases in calculating the open-circuit fault distance. The results obtained show that a distance relay with the proposed scheme will not only be able to detect the open-conductor condition in HVTL (high voltage transmission line) but also to locate the place of this fault regardless the value of the pre-fault current loading. There is no need for especial communication schemes since the existing media could work properly for the needs of the proposed technique. 展开更多
关键词 Distance relay open-conductor ANN transmission networks fault location.
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Power System Modelling and Fault Analysis of NamPower's 330 kV HVAC Transmission Line
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作者 Innocent Davidson Immanuel Mbangula 《Journal of Energy and Power Engineering》 2014年第8期1432-1442,共11页
Electric power systems usually cover large geographical areas and transmission facilities are continuously increasing. These power systems are exposed to different environmental conditions which may cause faults to oc... Electric power systems usually cover large geographical areas and transmission facilities are continuously increasing. These power systems are exposed to different environmental conditions which may cause faults to occur on the system. Different types of studies are usually done on electric power systems to determine how the system behaves before, during and after a fault condition. The behaviour of variables of interest such as currents, voltage, rotor angle and active and reactive power under fault conditions are studied and observed to help determine possible causes of faults in a power system. The objective of this paper is to investigate a fault that occurred on the 330 kV transmission line between Ruacana power station and Omburu sub-station, the fault caused all the generators at Ruacana power station to trip and consequently caused a blackout at the power station that lasted for 6 h. Preliminary findings showed that the observed fault was an earth fault but the exact type of earth fault was however not known at the time. This research investigation sets out to determine the exact fault that occurred; the most probable cause of the fault, and propose possible solutions to prevent reoccurrence of such a fault. The section of the power network in which the fault occurred was modelled using DigSilent Power Factory software tool, and transient fault analysis was carried out on the model for different fault conditions. Results obtained were then compared with data obtained from NamPower records to ascertain the type of fault. 展开更多
关键词 Fault analysis power system transient stability
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Fault component integrated impedance-based pilot protection scheme for EHV/UHV transmission line with thyristor controlled series capacitor(TCSC) and controllable shunt reactor(CSR) 被引量:1
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作者 HE ShiEn SUONAN JaLe +1 位作者 KANG XiaoNing JIAO ZaiBin 《Science China(Technological Sciences)》 SCIE EI CAS 2013年第2期342-350,共9页
This paper analyzes the fundamental frequency impedance presents a novel transmission line pilot protection scheme characteristic of a thyristor controlled series capacitor (TCSC) and based on fault component integr... This paper analyzes the fundamental frequency impedance presents a novel transmission line pilot protection scheme characteristic of a thyristor controlled series capacitor (TCSC) and based on fault component integrated impedance (FCII) calculated for a transmission line with TCSC and controllable shunt reactor (CSR). The FCII is defined as the ratio of the sum of the fault component voltage phasors of a transmission line with TCSC and CSR to the sum of the fault component current phasors where all the phasors are determined at both line's terminals. It can be used to distinguish internal faults occurring on the line from external ones. If the fault is an external one the FCII reflects the line's capacitive impedance and has large value. If the fault is an internal one on the line the FCII reflects the impedance of the equivalent system and the line and is relatively small. The new pilot protection scheme can be easily set and has the fault phase selection ability and also it is not affected by the capacitive current and the fault transition resistance. It is not sensitive to compensation level and dynamics of TCSC and CSR. The effectiveness of the new scheme is validated against data obtained in ATP simulations and Northwest China 750 kV Project. 展开更多
关键词 EHV/UHV transmission line pilot protection fault component integrated impedance (FCII) thyristor controlled seriescapacitor (TCSC) controllable shunt reactor (CSR)
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