A new approach to phase selection using fault generated highfrequency noise and neural networks

Single-pole autoreclosure is quite extensively used in long-line applications and involves tripping only the faulted phase for single-phase earth faults. Reliable and fast phase selection is thus imperative in order to avoid potential problems of system insecurity and instability. Conventional phase selectors, primarily based on power frequency measurands, can suffer some impairment in performance because of their heavy dependency on varying system and fault conditions. However, the advent of artificial neural networks (ANNs), with their ability to map complex and highly nonlinear input/output patterns, provides an attractive potential solution to the long-standing problems of accurate and fast phase selection. This paper describes the design of a novel phase selector using ANNs. The technique is based on utilising fault generated high frequency noise (captured through the high voltage coupling capacitor of a conventional capacitor voltage transformer) to essentially recognise the various patterns generated within the frequency spectra of the fault generated noise signals on the three phases, for the purposes of accurately deducing the faulted phase. The paper demonstrates a new concept and methodology in phase selection which will facilitate single-pole autoreclosure applications in power systems     

故障信息处理系统中继电保护装置的可靠性研究

针对继电保护装置的工作特点拟定了继电保护装置可靠性的特征量。建立了继电保护装置可靠性的马尔可夫模型,运用状态空间法进行可靠性分析。最后提出了如何利用故障信息处理系统中大量丰富的信息实现继电保护装置可靠性分析的方法。     

Power system distributed on-line fault section estimation usingdecision tree based neural nets approach

This paper proposes a distributed neural net decision approach to online estimation of the fault section of a transmission and distribution (T&D) system. The distributed processing alleviates the burden of communication between the control center and local substations, and increases the reliability and flexibility of the diagnosis system. Besides, by using the algorithms of data-driven decision tree induction and direct mapping from the decision tree into neural net, the proposed diagnosis system features parallel processing and easy implementation, overcoming the limitations of overly large and complex systems. The approach has been practically tested on a typical Taiwan Power (Taipower) T&D system. The feasibility of such a diagnosis system is presented     

故障信息处理系统中继电保护装置的可靠性研究

针对继电保护装置的工作特点拟定了继电保护装置可靠性的特征量.建立了继电保护装置可靠性的马尔可夫模型,运用状态空间法进行可靠性分析.最后提出了如何利用故障信息处理系统中大量丰富的信息实现继电保护装置可靠性分析的方法.     

An approach for intelligent detection and fault diagnosis of vacuum circuit breakers

In this paper, an approach for intelligent detection and fault diagnosis of vacuum circuit breakers is introduced, by which, the condition of a vacuum circuit breaker can be monitored on-line, and the detectable faults can be identified, located, displayed and saved for the use of analyzing their change tendencies. The main detecting principles and diagnostics are described. Both the hardware structure and software design are also presented.     

SF6断路器故障辨识及在线监测的探讨

根据国内外有关SF6断路器故障统计和事故分析,提出SF6断路器故障模式和辨识指标,旨在改变断路器传统的定期检修方式。按照本文提出的故障模式和辨识指标,时SF6断路器进行在线监测,可实现“按状态检修”或“以可靠性为中心检修”的先进检修模式,有利于提高SF6断路器的可靠性,避免危及系统安全的严重事故发生,降低断路器检修维护费用。     

Development of custom LSIs for protective relays and theirevolution to new static relays

A relay LSI and a filter LSI are developed for static distance relays. The relay LSI is based on the phase-comparison scheme and applicable to a reactance relay, a mho relay, an offset mho relay, and an ohm relay. Key technologies used to meet the relay requirements are CMOS switched-capacitor technologies. Circuit compositions and characteristic test results are described. A prototype relay unit demonstrated superiority to a conventional unit in terms of its compactness. High reliability (because of the small number of parts), high accuracy, and very low power dissipation     

Improvements of protective characteristics of automatic low-voltage circuit breakers

Suggestions on how to improve the protective characteristics of automatic low-voltage breakers, namely, to increase the sensitivity to remote short-circuits (faults), to raise the speed of selective protection, and to enhance the reliability by long-distance (remote) backup are considered. The use of the power function of a current to quickly identify the reason for a circuit disturbance and determine the rms current value of the current’s periodic component is grounded. Advantages of the use of the Joule integral as a criterion to selectively operate breakers are shown. Original Russian Text ? V.E. Rainin, A.S. Kobozev, 2009, published in Elektrotekhnika, 2009, No. 2, pp. 44–51.     

SF6断路器综合在线监测系统的开发

SF6高压断路器综合在线监测系统可以同时对多组断路器运行时的相关参数进行全面测量,为故障的综合诊断提供依据.在对SF6断路器运行状态进行实时监测的同时,通过建立数据库,实现对断路器在线监测数据的历史和横向的管理,有利于断路器在线监测信息共享,具有用户界面友好,易于维护等特点.     

高压开关事故分析和故障对策

本文对2004年国家电网公司系统高压开关设备的事故和障碍进行了统计分析,提出了技术对策,可供电力系统运行部门和高压开关制造厂参考。1概述截止到2004年底,国家电网公司系统(以下简称“公司系统”)7.2~550 kV高压断路器(含GIS间隔数)装用量总计为275 373台。72.5 kV及以上电压     

SF6断路器分布式在线监测系统的研制

本文研制了一种分层分布式SF6断路器在线监测系统,该监测系统主要由监控中心主机、现场数据采集单元和网络通信处理单元组成。系统上层网络采用以太网的通信方式,下层网络采用CAN总线的通信方式。对SF6断路器故障诊断所需的在线监测系统进行了分析,详细阐述了在线监测系统各部分的硬件结构及软件实现。经现场运行表明,该系统布线少、配置灵活、传输数据可靠,并具有可扩展性。     

A new approach to fault section estimation in power systems using Ant system

In this paper, a new method to fault section estimation problem in power systems is developed using Ant System. Based on the information from the operated protective relays and tripped circuit breakers, the fault section estimation is first formulated as a combinatorial optimization problem. Then, a new approach known as the Ant System is applied to solve this optimization problem. The Ant System is suitable for solving problems of combinatorial optimization by means of agents that work in parallel, among a population and without a supervisor in a cooperative manner. Finally, a sample power system is used to demonstrate the efficiency of the Ant System based method. From these test results, it appears that the Ant System is of promise for the fault-section estimation problem.     

基于神经网络非线性系统的故障诊断研究

提出了一种关于变工作点非线性系统故障诊断研究的新方法。将此类非线性系统用变参数线性系统表示,其中模型参数为可测量工作点及故障的函数。基于Hopfield神经网络,估计系统模型参数,引入“参考工作点”这一新概念,根据模糊聚类分析方法,确定故障种类。最后,在某位置伺服系统故障诊断研究中证实了这种方法的有效性。     

新一代中压真空断路器(VCB)

一、前言 真空断路器在中压(6～36kV)电网是占优势的电器,以欧洲和美国为例,VCB在全部产出的各种断路器中占70%,日本近100%.俄罗斯的VCB产量呈稳定增长,1997年VCB的份额占全部的50%以上.VCB和油断路器及充气断路器(GCB)相比,其作用在市场上被看好的主要优点有:     

高压断路器综合在线监测系统的研制

高压断路器是电力系统的重要设备，高压断路器的状态监测一直是电力系统十分关注并迫切希望解决的问题之一。本文介绍一种基于INTEL80C196KC单片机和PSD4135可编程芯片的高压断路器综合在线监测系统。该系统实现了对断路器运行过程中的机械特性、绝缘特性和输电线路中短路电流进行实时监测，并采用双总线通信方式实现数据的传输，解决总线冲突问题。经试验验证，该系统具有实时性高、稳定性好等优点。     

基于IEC最新标准的继电保护及故障信息处理系统设计

提出了基于通用监控软件平台和最新国际标准IEC61850和IEC61970的继电保护及故障信息处理系统全新设计思路.全面阐述继电保护及故障信息处理系统的组成及各项功能.     

基于IEC最新标准的继电保护及故障信息处理系统设计

提出了基于通用监控软件平台和最新国际标准IEC61850和IEC61970的继电保护及故障信息处理系统全新设计思路。全面阐述继电保护及故障信息处理系统的组成及各项功能。     

一种新型的微机型断路器开断检测装置

介绍已研制成功的微机型断路器开断检测装置 ,该装置以MCS - 5 1系列单片机为核心部件 ,能同时检测八台断路器的开断时间和短路电流值以及各台断路器的开断总次数和短路电流的累计值 ,真实地反映出断路器的设备状况 ,从而依据断路器检修规程确定检修时间。按照断路器的实际开断情况选择适当的检修时间 ,将避免以往那种不必要的检修工作 ,提高经济效益     

一种新型的微机型断路器开断检测装置

介绍已研制成功的微机型断路器开断检测装置,该装置以MCS-51系列单片机为核心部件,能同时检测八台断路器的开断时间和短路电流值以及各台断路器的开断总次数和短路电流的累计值,真实地反映出断路器的设备状况,从而依据断路器检修规程确定检修时间.按照断路器的实际开断情况选择适当的检修时间,将避免以往那种不必要的检修工作,提高经济效益.     

A single ended directional fault section identifier and fault locator for double circuit transmission lines using combined wavelet and ANN approach

Fault section identification and determining its location are important aspects to reduce down/repair time, speed up restoration of power supply and to improve the reliability. In this paper combined wavelet and artificial neural network based directional protection scheme is proposed for double circuit transmission lines using single end data to identify the faulty section and its location with reach setting up to 99% of line length. The proposed method requires the three phase currents and voltage to be measured at one end of the double circuit transmission line modelled using distributed parameter line model which also considers the effect of shunt capacitance. Approximate coefficients feature vector of the three phase voltage and current are extracted using discrete wavelet transform to train the ANN with Levenberg Marquardt algorithm. The proposed scheme involves two stages. The first stage identifies the zone/section of the fault and the second stage calculates the fault location from the relaying point. The proposed combined Wavelet and ANN based fault location scheme is also compared with ANFIS based fault location scheme. The test results of the proposed scheme show that the fault section identification and location estimation is very accurate and the average percentage error in fault location estimation is within 0.001%. This method is adaptive to the variation of fault type (both forward and reverse), fault inception angle, fault location and fault resistance. The main advantage of the proposed scheme is that it offers primary protection to 99% of line length using single end data only and also backup protection to the adjacent forward and reverse line sections.