开关柜内部故障电弧探测法的研究现状及趋势

鉴于故障电弧是电力系统开关柜内部的灾难性故障之一,综合分析了国内外对故障电弧探测方法的研究及应用现状,在对现有各种故障电弧探测方法进行介绍和分析,指出各种探测方法的技术特点、局限性和适用范围的基础上,提出了故障电弧的早期预测预警探测方法及故障电弧探测算法智能化的发展趋势。通过研究和提取故障电弧放电前伴随的早期弧声、弧光的特征信息,实时在线监测该特征弧声、弧光是否存在即可断定故障电弧是否将会发生,从而改变了目前故障电弧的事后被动检测。可实现基于特征弧声、弧光的早期预测预警防护机制,把故障消除在发生早期,降低和避免了故障电弧产生时对开关设备造成的损失。     

A new approach to the arcing faults detection for fast autoreclosure in transmission systems

To avoid automatic reclosing on permanent faults, a new numerical algorithm for power transmission network arcing faults detection has been developed. Some important features of a long arc in air are investigated and used as a basis in the algorithm design. The fact that the nonlinear arc behavior influences other voltages and currents distorting them, offered an opportunity to detect the arc by measuring and processing the transmission line terminal voltage and current. A series of simulation studies have shown that the algorithm can be used as an effective tool for arcing faults detection.<>     

New insight into the detection of high-impedance arcing faults onDC trolley systems

High-impedance arcing faults are difficult to detect with conventional switchgear, and the presence of these faults in coal mine power systems represents a significant fire hazard. Research was performed to identify plausible techniques that would discriminate between the high-impedance arcing faults and legitimate load currents on the DC trolley system. This paper briefly summarizes that effort and focuses on the frequency characteristics of the arc current. After the arc was modeled as a stochastic process, good agreement was obtained between experimental observations and mathematical predictions     

基于CatBoost的常用电器负载电弧故障识别方法

电气火灾造成的危害日益受到人们重视,其成因中占比最大的是电弧故障。电弧通常是由电气组件的损坏或过载而导致,进而可能会导致电气设备的损坏并引发火灾。电弧识别是一种重要的电弧故障预防性技术,可以监测电气设备中的电弧事故,以便及时采取应对措施,是智能用电的重要组成部分。文中就电弧故障识别方法展开研究,首先按照国标搭建了实验平台,然后分析不同家用电器负载组合的电弧特征,并进行特征提取;接着提出了一种基于CatBoost分类模型的电弧识别方法,使用CatBoost模型对提取到的特征进行训练,以实现电弧故障的快速识别;经过测试集验证,与现有的SVM、Random Forest等常用识别分类方法相比,提出的基于CatBoost分类模型的电弧识别方法具有更高的准确率和召回率,能够有效提高电弧事故的识别精度。     

Determination of the Cause of Arcing Faults in Low-Voltage Switchboards

It is widely recognized that arcing faults in switchboards contain large amounts of power and can create significant damage, including melting switchboards, destroying substations, disabling ships, and causing human fatalities. While arcing faults occur with a fairly high frequency, electricity is so ubiquitous in our lives that most engineers will not personally be associated with a major arcing fault. The Navy has invested 25 years investigating the causes, behavior, and prevention of arcing failures in low- and medium-voltage switchboards. Laboratory testing used to help understand the behavior of arcs in switchboards is presented. Those data are then used to analyze actual switchboard arcing events and, thus, to determine the root causes of the events. Additional testing used to confirm the cause of each event is discussed.     

直流牵引系统馈线微机保护装置

直流牵引系统馈线远端非金属性小短路电流故障是直流牵引系统馈线保护的难点。文中阐述了电流变化量保护原理,分析了牵引馈线远端经电阻短路和电弧短路故障电流的变化特征;提出采用电流变化率为启动元件电流增量检测的主保护判据,并针对电弧故障电流变化特征提出电流增量辅助保护判据,两者相结合实现直流牵引系统馈线保护方案;详细分析了不同情况下保护判据的动作特性及整定原则;以该保护方案为基础研制开发了馈线微机保护装置,并通过了保护测试与现场试验。     

基于磁通控制消弧线圈的注入式选线新方法

提出了一种谐振注入式接地故障选线新方法,可用于谐振接地系统单相接地故障选线。该选线方法充分利用了基于磁通控制消弧线圈的运行特点以及谐振频率电流能够突出故障信息的特点,可注入较大幅值的谐振频率电流以增强故障信息。其原理是在接地故障发生前后分别通过消弧线圈二次侧的逆变器注入相同的谐振频率电流,对电力系统零序参数形成2次快照,采用比值法及增补判据对2次快照的电流值、电压值进行分析,判定不满足相关判据的回路为故障线路。理论研究及仿真证实,该方法可以在消弧线圈补偿的同时进行选线,可以有效地检测高、低阻接地故障。     

The arc terminator

Preventing the increase in pressure within a piece of metal-clad switchgear due to an uncontrolled open arcing fault can be achieved by using an arc terminator. The arc terminator constitutes a bypass system that confines the effect of an arcing fault to its point of initiation. It is composed primarily of a high-speed mechanical switch, and an electronic control module. In the event of an arcing fault, the switch closes in less than 4 ms to provide a solid conducting path for the fault current. The concept of the bypass system has been proven to be a viable alternative to the methods currently used for arc protection for switchgear equipment. This concept has further demonstrated that it can not only offer personnel protection, but can also protect the associated surrounding equipment. Finally, this type of technology is not limited only to metal-clad switchgear or new equipment; it can easily be applied to metal-enclosed equipment or retrofitted into existing equipment as long as the interrupting devices being used are not of the air-magnetic type or any other type where the interrupting chamber is not a sealed chamber.     

基于高频重构信号与Bayes-XGBoost的低压电弧故障辨识方法研究

针对低压配电系统中单个用电负载支路串联电弧故障辨识困难的问题,提出一种基于高频重构信号和Bayes-XGBoost的低压电弧辨识方法。首先,搭建多支路、多负载类型的低压电弧故障真型实验平台,并采集相关数据。其次,基于故障前后主线路电流高频信号变化规律,提出信号微弱变化叠加法重构故障有效信号。最后,建立适用于单个负载支路电弧故障辨识的XGBoost模型,并采用Bayes算法对模型多个超参数进行优化。实验结果表明,所提方法在多种工况下对单个负载支路电弧故障具有较高的辨识准确率。与6种主流故障分析方法对比,所提方法在精度、训练速度和泛化能力等方面展现出了显著的优越性,有利于实现低压配电系统单个负载支路电弧故障的可靠辨识。     

Smart detection technology of serial arc fault on low-voltage indoor power lines

This paper employs the discrete wavelet transform (DWT) and an artificial neural network to identify the occurrence of serial arc faults on indoor low voltage power lines. Electric arc faults on power lines must be detected in order to turn off the electric power sources before fire events occur. However, since the characteristics of line current waveforms during serial arc faults are complicated, smart detection technology is required to have high accurate recognition. The DWT is utilized to obtain the time-domain characteristics of line current waveforms, and the signal energy of some sub-bands is useful information to reflect the serial arc fault patterns. And then, a radial basis function neural network (RBFNN) is trained by using the data of signal energy obtained from DWT. After the training process, the RBFNN has excellent ability to identify the serial arc-fault conditions. At last, the accumulative RBFNN outputs of 30 power cycle line current data are used to certify the occurring of a serial arc fault on the line. This study also compares the results of detecting serial arc faults with a commercial arc-fault circuit interrupter (AFCI) to reveal the goodness of the purposed method.     

电压电流能量信息融合的低压交流电弧故障检测

针对串联电弧故障检测判据选择难、阈值设置难的问题,本文在传统基于电流检测方法的基础上融合使用电压信息,提出了一种电压电流能量信息融合的交流电弧故障检测方法。以分析开关电源和非开关电源类负荷下的各自故障特征为基础,提出了利用电压半波总能量的开关电源类电弧故障直接判定方法,并融合使用电压电流特征能量波形相关性实现故障线路的选择;提出了基于敏感域电压电流最大瞬时特征能量相位匹配的适用于非开关电源类负荷下的故障检测方法,以特征能量相位信息构建判据,克服了传统检测方法的阈值设定困难问题。本文检测方法判据虽利用了负荷分类思想,但由于开关电源类负荷下的故障检测可利用电压半波总能量幅值实现故障直接判定,因此实际应用中无需辨识负荷类型。相较传统利用电流特征的检测方法,本文方法具有判据简单、易于阈值设定的优势。试验结果表明,本文方法可有效用于多种类型负荷的电弧故障检测,检测时间满足相关标准规定。     

基于小波分析的故障电弧伴生弧声特征提取

在故障电弧伴生早期弧声频谱特性研究的基础上,提出基于小波包分解的早期弧声频带局部能量特征参数的快速提取方法。早期弧声的功率谱分析表明,故障电弧发生之前,在可听波段产生5kHz-10kHz的电弧声,其带宽和中心频率与电极形状、放电距离、放电电压等试验条件有关。利用小波包多分辨率技术对弧声信号进行三层分解,对各子频带进行能量统计,根据不同子频带能量的分布特征建立起“能量一信号”的映射关系。实验研究表明,弧声出现前后第二子频带S31和第三子频带S32能量变化明显,可以作为识别早期弧声的特征参数。通过在线监测信号这两个特征子频带能量的变化即可判断早期故障弧声是否存在,从而实现故障电弧的早期预测预警。     

高速电气化铁路中的弓网电弧现象研究综述

高速电气化铁路弓网系统中的电弧已经成为制约我国高速铁路发展的技术瓶颈。笔者论述了电弧对接触导线、受电弓滑板、通讯信号、无线电信号和供电质量等的危害,从电弧产生的机理和特征、电弧模型、电弧能量、电弧侵蚀和载流摩擦磨损方面综述了相关电弧问题的研究现状,为深入开展弓网电弧现象、机理及抑制措施的研究打下了基础。     

基于双频有源调控的大型机组定子接地故障电弧抑制及自适应保护

随着“碳达峰、碳中和”目标部署的实施，在新型电力系统中，因大型旋转电机需要担负更重要的功率调控和稳定支撑作用而对其提出了更高的安全平稳运行要求。对于最易发生的定子接地故障，如何有效抑制机组电弧损伤和避免刚性切机冲击显得尤为重要。首先提出基于双频有源调控的大型机组定子接地故障消弧和限流方法，可实现瞬时性故障治愈、永久性故障安全限流，保障定子铁心安全。其次提出与有源消弧协同的接地故障自适应保护方法，可实现柔性平稳切机控制，提高机组和电网的安全性。最后通过仿真和动模试验验证了所提方法的有效性，其消弧和限流效果优于现有无源消弧方法。     

低压串联电弧故障通用诊断方法的研究

低压串联电弧故障是引发电气火灾的重要原因之一。利用MATLAB软件,建立基于CASSIE模型的低压串联电弧故障仿真电路,对单一和混合负载下的串联电弧故障电流波形进行小波变换的可视化分析,结合实测电弧故障电流研究了不同负载下电弧故障的共同特征,提出了基于小波分解细节分量阈值的通用诊断方法并利用LabVIEW软件编制了诊断程序,在线路供电端实现了对各类串联电弧故障的识别,为电弧故障通用诊断的实现和应用提供了理论依据和实验方法。     

配电网单相电弧接地故障选线暂态分析法

小电流接地系统发生最多的故障是单相接地故障，现有的基于稳态零序电流的故障选线方法，受弧光接地，运行方式因素的影响较大，选线精度并不理想，文中在充分研究电弧故障暂态零序电流变化的基础上，指出电弧因素对故障选线准确性的影响，由于对称分量法对接地故障进行暂态分析十分不便，文中采用Clarke变换，并运用小波变换技术建立新的基于暂态电气量的选线方法，应用EMTP对电弧接地故障进行了仿真，在不同采样频率以及不同的A／D分辨率情况下进行了大量的仿真试验，结果表明该方法是正确，有效的，而且具有较强的鲁棒性。     

Understanding IEEE 1584 arc flash calculations

This paper presents the IEEE 1584 guide for calculating arc-flash energies and arc flash protection. There are different methods included in this guide for calculating the arc flash associated with circuit breakers. The most accurate method included is to acquire specific device characteristics from the circuit breaker manufacturer. When this information is not available, the IEEE guide also includes a secondary circuit breaker method which is more conservative, and therefore calculates high values of arc energy that may mandate more protection than is necessary.     

Predicting Damage from 277-V Single Phase to Ground Arcing Faults

Laboratory tests of arcing faults trapped between a corner of a simulated steel housing and single or multiple bus bars were found to be reasonably reproducible and caused relatively consistent burning damage. Single phase 277-V arcing fault tests using spacings of 1 to 4 in from bus bars to ground at current levels of about 3000 to 26 000 A indicate that damage is proportional to I1.5t. In this ``ballpark' arc voltage and arc length need not be known to predict probable maximum damage. For coordinated short circuit and ground fault protection, an arbitrary practical limit is proposed such that I1.5t is numerically not greater than 250 times the ampere rating of the circuit. Probable maximum burning damage in cubic inches of copper, aluminum, and steel is predicted based on the tests. The arbitrary limit is achievable with commercially available equipment using simple time current band coordination. Lower limits can be achieved using more sophisticated ground fault protection equipment.     

Arc characteristics and a single-pole auto-reclosure scheme for Alexandria HV transmission system

Arcing faults are the most common faults that occur in the 220 kV transmission line national grid of Egypt, in the vicinity of ‘Alexandria’ city. This part of the network also feeds a large industrial load in the form of steel works, which injects a large amount of harmonics into the network. In this paper, the performance of this 220 kV TL network during arcing faults is studied with the aid of the PSCAD/EMTDC program together with a specially designed arcing fault custom model incorporated in the program. Several arcing faults are simulated, and the effect of harmonics on the fault current and secondary arc duration time is demonstrated. Based upon the simulation results, recommendations regarding single-pole autoreclosing and arc suppression methods are suggested.     

炸气流灭弧性能及应用效果分析

为了研究爆炸气流灭弧防雷间隙的灭弧特性,通过对该灭弧防雷间隙的爆炸气流工频灭弧试验,得出了该灭弧防雷间隙的工频续流电弧在4 ms时间内即被强气流吹灭,气流维持时间大于6 ms。同时建立链式电弧模型和Mayr电弧模型分别对电弧所受气流压力和爆炸气流灭弧防雷间隙的能量散失特性进行研究,并利用力学软件ANSYS14.0对强气流干扰下的电弧能量进行仿真分析。从结果分析可知电弧在气流强压力作用下能量迅速耗散,并在极短时间内被截断熄灭。在实际运行中,降低雷击事故率97%,灭弧效果明显。