基于μC/OS-Ⅱ与LabVIEW的井下低压选择性漏电保护系统研究

针对低压中性点不接地系统漏电保护系统存在的缺陷,设计了一种基于μC/OS-II与LabVIEW的井下低压选择性漏电保护系统。该漏电保护装置采用集中控制模式与零序电流相对比幅法、零序电流方向法和零序电流群体比幅比相法相结合的漏电选线方法完成数据采集;监控软件实时监测井下低压电网运行状态,对漏电故障进行报警和记录。应用表明,该漏电保护系统人机界面友好,能够可靠、快速地实现漏电保护,提高了低压电网供电的稳定性。     

矿山电网漏电保护的研究

分析了矿山电网供电的特点 ,给出了附加直流电源的电流与系统绝缘电阻的关系 ,系统正常运行与漏电故障时导纳的变化。提出了基于附加直流电源和导纳 (有功导纳 )增量原理的漏电保护新判据。介绍了基于这些原理的微机漏电保护装置 ,经现场运行表明选线准确、可靠。     

基于电力载波的选择性漏电保护

分析了目前矿井低压电网漏电保护系统存在的不足,提出了基于电力载波通信的新型选择性漏电保护实现方案,介绍了装置的组成和工作原理.实验证明,该装置构成的漏电保护系统具有实时性强、选择性判断准确和可靠性高等优点.     

矿井低压电网单相漏电选择性保护方法与装置的研究

文章简述了我国矿井低压电网漏电保护的技术概况,指出矿井低压漏电保护系统及选漏保护器存在的问题,着重阐明了基于零序基波"时序鉴别原理"的低压选漏保护器的基本结构、工作原理、使用方法、产品的主要特性和优点。     

对农村低压电网漏电(剩余电流)保护的几点认识

为提高对漏电保护的认识、做好低压电网漏电保护工作、进而为减少人身触电事故,从220/380V三相四线制采用TT系统特点出发,论述低压电网漏电保护的原因,电网三相不平衡漏电电流对漏电总保护的影响、实施全网漏电分级保护的必要性、如何做好漏电分级保护级间配合问题、漏电分级保护中各级保护器的选型、漏电保护器安装接线和电网运行方面需注意的几个问题,作一小结,供参考。     

房山变电站35 kV并联电抗器中性点不平衡电流的调整

矿井低压电网漏电保护经历了3个发展阶段、2次飞跃。在简要回顾矿井 压电网漏电保护技术发展史的基础上,介绍了矿井低压电网漏电保护技术的进展,其中包括机电式漏电保护、半导体式漏电保护、微机式漏电保护和自适应式漏电保护。     

矿井低压选漏保护技术和装置的创新与发展

随着矿井电网的出现,漏电保护技术就相伴而生。早在20世纪30年代,英国就在矿井低压磁力启动器中装设了漏电保护装置,从此就有了矿井低压电网漏电保护技术,但这种漏电保护装置只适用于变压器中性点直接接地的供电系统。20世纪40年代,苏联开始研制中性点不接地供电系统使用的漏电保护装置（PYB型防爆漏电继电器）。     

智能低压集中选择性漏电保护测控装置开发

在分析国内漏电保护装置现存问题的基础上,提出了一种基于群体比幅比相和零序电流幅值法原理综合利用,可以智能实现漏电保护的横向、纵向选择性的矿井低压电网集中选择性漏电保护系统。该系统以32位DSP处理器为核心,重点讨论该系统的工作原理、硬件结构、软件设计。经现场运行实现了漏电保护的快速性、选择性和准确性。     

基于零序电流方向的选择性漏电保护系统的研究

在分析国内外漏电保护装置现存问题的基础上,文章提出了一种基于零序电流方向的矿井低压电网选择性漏电保护系统,重点讨论该系统的工作原理,硬件结构,软件设计及抗干扰技术,最后介绍试验结果和应用情况。     

当前农网低压漏电保护技术状况浅析

1、前言农网改造通过推广新型漏电保护器、提高电网绝缘水平、推广末端保护,大幅提升了低压漏电保护水平。当前还存在动力房未安装三相漏电开关、没有注意单相负荷用户在三相均衡分配等问题,亟待解决。农网改造前,农村低压漏电保护状况有三个明显特点:1.低压电网技术状况差,主要是配电屏陈久失修,低压线路质量低劣、绝缘状况差;2.没有实现完善的末端保护;3.农村低压漏电总保护多由电流型漏电继电器充当。其有下列不足之处:①不能区分突变漏电(触电)和电网缓慢漏电;②不灵敏相问题影响总保护的正确动作率;③漏电大的电网总保护频繁动作,影响…     

基于配电自动化系统的单相接地定位

为了更好地进行配电网单相接地定位,提出一种将单相接地定位装置的信息直接上报配电自动化主站进行单相接地定位的方法,论述了利用配电自动化系统主站已有相间短路故障定位判据实现单相接地定位的基本方法,分析和介绍了各种单相接地定位原理的两值性和分化性特征及处理方法以满足主站定位判据的要求,论述了利用来自各个位置的单相接地定位信息之间的相互关联性,以及多种定位原理上报的定位信息的冗余性并采用贝叶斯方法实现容错定位的原理。所提方法无需改变已有配电自动化系统主站,也无需传送波形信息,即能正确实现单相接地定位。结合具体工程实例给出了现场测试和实际应用情况。     

Protection of Low-Voltage DC Microgrids

In this paper, a low-voltage (LV) dc microgrid protection system design is proposed. The LV dc microgrid is used to interconnect distributed resources and sensitive electronic loads. When designing an LV dc microgrid protection system, knowledge from existing dc power systems can be used. However, in most cases, these systems use grid-connected rectifiers with current-limiting capability during dc faults. In contrast, an LV dc microgrid must be connected to an ac grid through converters with bidirectional power flow and, therefore, a different protection-system design is needed. In this paper, the operating principles and technical data of LV dc protection devices, both available and in the research stage, are presented. Furthermore, different fault-detection and grounding methods are discussed. The influence of the selected protection devices and grounding method on an LV dc microgrid is studied through simulations. The results show that it is possible to use available devices to protect such a system. Problems may arise with high-impedance ground faults which can be difficult to detect.      

多分支配电网接地故障定位的特征向量法

在配电网接地故障定位传递函数法的基础上,提出了一种能够方便应用于多分支配电网接地故障定位的新方法——特征向量法。该方法利用数字信号处理手段获得具有一定分支结构的配电网的传递函数频谱特性,通过对频谱特性的进一步处理,获得故障线路中故障和分支的信息,并将这些信息转化为故障特征向量。对于某一固定分支结构的配电网,利用该方法建立各种故障特征的数据库,形成数据库专家咨询系统,以实现对多分支配电网接地故障的定位。     

配电网消弧装置应用中相关问题的研讨

分析了几种常用消弧装置对配电网中内部过电压防护的作用和效果;综合考虑了变电站、开闭所接地选线的实现,以及配电网自动化系统中接地故障区段定位等问题;结合现场运行实践,给出了消弧装置应用的指导原则和技术建议。提出了对于电缆化比例较大的配电网,宜选用自动跟踪补偿消弧装置,为了实现可靠接地保护及区段定位,短时加并中值电阻是一种较好的解决方案;延时加并高值电阻方案,也值得进一步研究;建议对于以架空线路为主的配电网,可以考虑选用新型消弧及过电压保护装置,并对该装置加以完善。     

储能设备接入配电网的新运行方式及其可靠性计算

随着越来越多的储能设备接入配电网,储能设备对配电网可靠性的影响引起人们的广泛关注。通过分析储能设备接入配电网后对配电网常用的两种保护系统的影响,提出了一种针对大量接入储能设备的、以断路器和隔离开关为保护系统的配电网的新的运行方式。当故障发生时,可以缩小故障影响范围和故障时间,从而提高配电网可靠性。文末采用混合法计算两种运行方式下IEEE-RBTS BUS 6系统不同位置负荷的可靠性参数,通过仿真运行数据可知,在储能设备接入配电网后,可以明显提升网络末端负荷的可靠性。     

Optimal operation modes of photovoltaicbatteryenergy storage system basedpower plants considering typical scenarios

Emission of greenhouse gases and depletion of fossil fuel reserves are two key drivers, which are forcing the mankind to generate the future energy demand from the renewable energy resources. These resources are generally distributed in nature and are directly integrated at distribution levels. Increasing penetration of the distributed energy resources in distribution power networks creates additional operational and control issues. These are mostly regulatory, economical load dispatching, power quality and protection issues. Generally power distribution systems are protected with the help of dedicated over current based protection schemes. But increasing share of distributed energy resources penetration in electric utilities poses a serious threat to the existing protection coordination schemes of the distribution systems. Distributed energy resources connected distribution networks become interconnected in nature and protection coordination schemes, which are designed for unidirectional flow of fault currents become ineffective/non-functional. Therefore, new protection coordination schemes are required for providing the adequate protection coordination for distributed energy resources connected electric power networks. In the available literature, the protection coordination schemes for radial distribution systems and developments in the area of protection coordination are discussed in detail. A thorough review for all these protection coordination schemes for distribution systems with and without distributed energy resources is done in this review article. It includes the analytical and artificial intelligence based techniques application for coordination of protective relays in the distribution systems. The limitations and research gaps in the area of protection coordination schemes are also presented in this review article. The aim of this research paper is to bring all the available research in the area of relay coordination on one platform, so that it will help the emerging researcher to identify the future scope of relay coordination application for distributed energy resources connected distribution systems.     

Time series modeling and filtering methodof electric power load stochastic noise

Emission of greenhouse gases and depletion of fossil fuel reserves are two key drivers, which are forcing the mankind to generate the future energy demand from the renewable energy resources. These resources are generally distributed in nature and are directly integrated at distribution levels. Increasing penetration of the distributed energy resources in distribution power networks creates additional operational and control issues. These are mostly regulatory, economical load dispatching, power quality and protection issues. Generally power distribution systems are protected with the help of dedicated over current based protection schemes. But increasing share of distributed energy resources penetration in electric utilities poses a serious threat to the existing protection coordination schemes of the distribution systems. Distributed energy resources connected distribution networks become interconnected in nature and protection coordination schemes, which are designed for unidirectional flow of fault currents become ineffective/non-functional. Therefore, new protection coordination schemes are required for providing the adequate protection coordination for distributed energy resources connected electric power networks. In the available literature, the protection coordination schemes for radial distribution systems and developments in the area of protection coordination are discussed in detail. A thorough review for all these protection coordination schemes for distribution systems with and without distributed energy resources is done in this review article. It includes the analytical and artificial intelligence based techniques application for coordination of protective relays in the distribution systems. The limitations and research gaps in the area of protection coordination schemes are also presented in this review article. The aim of this research paper is to bring all the available research in the area of relay coordination on one platform, so that it will help the emerging researcher to identify the future scope of relay coordination application for distributed energy resources connected distribution systems.     

Development of a high-speed switching system for distributionnetworks

This paper describes a high-speed switching system for distribution networks which has been developed with the aim of improving power supply reliability (reducing the number of supply interruptions) of distribution systems. When a fault occurs in conventional distribution systems, the fault section is isolated using a sequential time-out control scheme which requires the reclosing and re-reclosing of the entire system. A major drawback of such systems is that normal sections are also subjected to unnecessary power supply interruptions. In order to resolve this problem, the authors have developed a high-speed switching system which isolates only the fault section without interrupting the power supply to normal sections. This new system can fully restore power to the normal sections and completely isolate the fault section within 500 ms in the case of a ground fault     

参数增量法在优化谐振接地方式中的应用

在补偿电网中发生单相接地故障时,继电保护选择性是国内外长期存在的一大技术难题。利用参数增量法研制成功的微机接地保护或自动选线装置,原理简明、灵敏度高、可靠性好,能够检出高阻接地故障,现已在我国的中压电网中投入运行。     

基于限流级差配合的城市配电网高选择性继电保护方案

为了解决供电半径短的城市配电网继电保护配合困难问题,提出了一种基于限流级差配合高选择性继电保护方案。在变电站出线断路器和联络开关配置限流保护装置,发生相间短路故障时,出线断路器限流保护装置迅速限流并与配置于馈线分段开关的保护装置实现多级级差继电保护配合;若为永久性故障,联络开关配置限流保护装置可以在限流条件下实现故障区域的隔离和健全区域恢复供电。结合实例详细论述了限流保护装置的组成和工作原理,着重论述了参数整定方法。分析结果表明:所建议的方法能够有效降低故障处理期间的短路电流水平和对设备的损害,不仅适用于架空配电网,而且也适用于电缆配电网。