电压互感器断线原理与应用

详细介绍了美国SEL公司SEL-311C、SEL-749M、SEL-751A电压互感器断线功能,及深圳南瑞公司的ISA-351G馈线保护、ISA-367G线路保护、ISA-353G线路光纤纵差保护、ISA-388G变压器后备保护、ISA-359G电容器保护和ISA-347G电动机保护的电压互感器断线功能,分析其逻辑原理,总结优缺点,提出了合理使用电压互感器断线功能的方法.美国SEL公司继电保护装置采用电压互感器断线逻辑判定电压互感器断线.可以灵活运用SEL继电器所具有的逻辑编程功能,编制电压、电流、断路器位置及时间等元件组成的逻辑方程.在电压互感器一相、两相或者三相断线时,进行电压互感器断线判别及进行电压互感器断线闭锁保护的应用.深圳南瑞公司继电保护装置具有母线电压互感器断线逻辑、线路电压互感器断线逻辑,其逻辑中含有电压、电流、断路器位置或时间等元件,在电压互感器一相、两相或者三相断线时,均能够进行电压互感器断线判别及进行电压互感器断线闭锁保护的应用.     

变电站电压互感器二次回路多点接地危害分析

分析了某500 kV变电站电压互感器二次回路接地引起的异常现象,探讨了对电压互感器二次回路多点接地的危害、查找方法,阐述了出现电压互感器断线时如何分析判断确定其性质,并正确进行故障分析查找。     

发电机机端电压互感器熔体慢熔导致励磁系统过励分析

对一起由发电机机端电压互感器熔体慢熔导致的励磁系统过励故障进行分析,确认原程序判断电压互感器断线逻辑不完善,导致励磁系统误增磁直至发电机过压保护动作、机组解列。对励磁系统的电压互感器断线判断逻辑进行了改进,消除了由熔体慢熔导致的励磁系统过励问题,提高了电厂的运行可靠性。     

发电机中性点电压互感器断线的检测方法

分析了发电机中性点电压互感器断线故障对定子单相接地保护的影响,指出中性点电压互感器断线将导致三次谐波电压比值型定子单相接地保护误动,但现有电压互感器断线判断方法不易检测该处的断线故障.利用单相接地故障发生时机端和中性点三次谐波电压故障分量近似相同的变化特点区分中性点电压互感器断线与中性点金属性接地故障,防止定子单相接地保护误动.     

发电机中性点电压互感器断线的检测方法

分析了发电机中性点电压互感器断线故障对定子单相接地保护的影响,指出中性点电压互感器断线将导致三次谐波电压比值型定子单相接地保护误动,但现有电压互感器断线判断方法不易检测该处的断线故障。利用单相接地故障发生时机端和中性点三次谐波电压故障分量近似相同的变化特点区分中性点电压互感器断线与中性点金属性接地故障,防止定子单相接地保护误动。     

发电机机端PT熔断器慢熔引起断线的故障检测方法研究

为解决发电机组机端PT(电压互感器)一次熔断器慢熔不能被PT断线判据所检测的问题,对目前基于电压平衡式原理的PT断线检测方法进行改进,提出了一种基于一次熔断器电流、励磁电压突变量、零序电压及其二次谐波电压含有故障特征量的PT断线判别方法。改进后的判据可同时适用于PT一次侧和二次侧断线的检测,能有效避免因熔断器慢熔而导致机组误强励和匝间保护动作。     

电流互感器及其二次回路若干技术问题的探讨

阐述了电流互感器减极性标注的概念,以及不同保护装置对电流互感器二次回路断线闭锁采取的不同逻辑;对比分析了规程对电流互感器二次回路接地方式的差异;剖析了油纸型电容型电流互感器二次绕组的特殊排列问题;探讨了电流互感器饱和问题,以及电流互感器10%误差曲线的简易校核方法。     

感应式三相三线电能表接线分析

联合接线的方式中,三相三线电能计量装置若发生电压互感器二次侧断线故障,在计算退补电量时如不考虑无功电能表电压线圈连接的影响,计算将存在误差。在不同相别断线时,无功电能表电压线圈对计量电量的影响不同。通过理论分析和实测数据,提出电压互感器二次侧断线计算退补电量时,应考虑无功电能表电压线圈的影响。     

电压互感器二次断线对三相三线计量的影响分析

本文结合智能电表计量特性,利用相量图法分析了电压互感器二次回路断线时接入三相三线电能表的二次侧电压幅值和相位的变化,并在此基础上提出了断线相的判别方法,推导了二次断线各种情况下的有功计量公式及更正系数的计算公式。     

母线保护电流互感器断线判据的分析及改进判据

母线差动保护一般都配置电流互感器断线判断功能,以提高差动保护的可靠性。按照现有规范,当母线支路发生电流互感器二次断线时,需闭锁差动保护;当母联间隔电流互感器发生断线时,不闭锁差动保护。因此电流互感器断线判据的选择将影响母线差动保护的正确动作。从大负荷电流互感器断线、不完全电流互感器断线、高阻接地故障、单电源系统等多个角度分析现有母线电流互感器断线的判据存在的问题,并在此基础上提出了新的母线电流互感器断线判据:对于接入电压的母线保护,采用灵敏的电压判据作为辅助判据,对于无电压引入的母线保护,采用支路零序电流与差流的比值及差值作为辅助判据。试验结果表明,所提判据能够准确有效地识别电流互感器断线与故障,当发生电流互感器断线时,可靠闭锁差动保护,而当母线发生故障时,不会影响差动保护的快速性。     

变压器差动保护动作特性的仿真研究

为了解决工程实际中继电保护装置的测试问题,针对变压器差动保护,利用Matlab软件,在建立单侧电源110 kV双圈变压器简单电力系统模型的基础上,进行变压器微机继电保护装置的仿真分析。探究了励磁涌流与剩磁及合闸初相角之间的关系以及励磁涌流中的谐波含量情况。基于此,采用二三次谐波制动及常规比率制动保护原理,研究了差动保护装置的动作特性。通过对仿真结果的分析,整定保护装置参数,并获取测试数据,用于测试实际继保装置。经实验验证:该方案能够有效进行变压器差动保护装置的测试,具有较好的工程实用性。     

青海省电力公司输变电设备全寿命统计分析

文章依据青海省电力公司输变电设施可靠性统计数据,选取使用数量大、程度高的110kV及以上输电线路、变压器、断路器、隔离开关和继电保护等五类设备进行统计,阐述了公司主要输变电设备基本情况及主要特点,对公司主要输变电设备使用寿命与国家电网公司、国际成熟电网水平进行了比较,分析了影响输变电设备运行寿命的主要原因。     

Relay setting considerations and operational experience of a long500 kV transmission line

The large capacitive susceptance, large load magnitude, and substantial phase unbalance before and after a single-pole trip operation have a substantial effect on the performance of the protective relaying systems of the Minneapolis-Duluth 500 kV line. Computer simulation studies show that correct operation of the relays can be assured if these effects are taken into consideration in determining relay settings. The selection, performance, and operation of the primary and secondary relay system are discussed, indicating that the relaying protection used achieved substantial security and dependability     

500kV茂名站继电保护及故障信息管理子站系统的实现

介绍了在500kV茂名站继电保护及故障信息系统实现过程中的主要经验,分析。系统结构及系统各组成部分的功能,并有效地解决存在的接入设备种类多、数据和信息复杂等问题,希望为其他子站的实现提供工程经验。     

500 kV茂名站继电保护及故障信息管理子站系统的实现

介绍了在500 kV茂名站继电保护及故障信息系统实现过程中的主要经验,分析系统结构及系统各组成部分的功能,并有效地解决存在的接入设备种类多、数据和信息复杂等问题,希望为其他子站的实现提供工程经验.     

Short-term wind power forecasting using adouble-stage hierarchical ANFIS approachfor energy management in microgrids

Determination of the output power of wind generators is always associated with some uncertainties due to wind speed and other weather parameters variation, and accurate short-term forecasts are essential for their efficient operation. This can efficiently support transmission and distribution system operators and schedulers to improve the power network control and management. In this paper, we propose a double stage hierarchical adaptive neuro-fuzzy inference system (double-stage hybrid ANFIS) for short-term wind power prediction of a microgrid wind farm in Beijing, China. The approach has two hierarchical stages. The first ANFIS stage employs numerical weather prediction (NWP) meteorological parameters to forecast wind speed at the wind farm exact site and turbine hub height. The second stage models the actual wind speed and power relationships. Then, the predicted next day’s wind speed by the first stage is applied to the second stage to forecast next day’s wind power. The influence of input data dependency on prediction accuracy has also been analyzed by dividing the input data into five subsets. The presented approach has resulted in considerable forecasting accuracy enhancements. The accuracy of the proposed approach is compared with other three forecasting approaches and achieved the best accuracy enhancement than all.     

暂态失稳引起大停电的可能性与对策研究

以某一将来实施分片运行的５００ｋＶ／２２０ｋＶ规划电网为对象,从暂态稳定的角度对系统发生大面积停电的可能性进行了分析研究,并从电网规划,运行管理,继电保护和自动装置等方面,就预防大面积停电事故提出对策,介绍了仿真计算所需的负荷模型,电源模型,输电线路模型,变压器模型等电网模型。     

Application of Haar functions for transmission line and transformer differential protection

The development of algorithms, based on Haar functions, for extracting the desired frequency components from transient power-system relaying signals is presented. The applications of these algorithms to impedance detection in transmission line protection and to harmonic restraint in transformer differential protection are discussed. For transmission line protection, three modes of application of the Haar algorithms are described: a full-cycle window algorithm, an approximate full-cycle window algorithm, and a half-cycle window algorithm. For power transformer differential protection, the combined second and fifth harmonic magnitude of the differential current is compared with that of fundamental to arrive at a trip decision. The proposed line protection algorithms are evaluated, under different fault conditions, using realistic relaying signals obtained from transient analysis conducted on a model 400 kV, 3-phase system. The transformer differential protection algorithms are also evaluated using a variety of simulated inrush and internal fault signals.     

Digital protective relaying algorithms and systems — An overview

This paper gives an overview of the digital algorithms and systems for protective relaying. First, digital relaying algorithms are discussed. Classification and categorization of the proposed algorithms are given. The major classes are: transmission line protection, transformer protection, bus protection, and generator protection. The categories correspond to the different schemes used for the signal processing. The discussion of algorithms is concluded by giving some basic results related to the comparison and selection of the algorithms. A particular methodology is proposed if one is to investigate and compare digital algorithms using more elaborate quantitative techniques. The second major topic discussed is related to the digital implementations of the protective relays. Major philosophies used in designing digital relaying systems are outlined. These philosophies include the following design approaches: a centralized relaying system using a minicomputer; a decentralized relaying system where each protection function is implemented using a separate microprocessor; an integrated relaying system where a number of dedicated microprocessors are connected together in a protection system; an integrated substation control and protection system. Finally, expected trends in the areas of algorithm developments and system implementations are indicated.     

高压线路微机保护装置零序回路接线正确性的判断

介绍了判断高压线路微机保护装置零序回路接线正确性的方法及判据,并对各种判据的理论依据进行了分析：（１）高压线路微机保护装置零序回路接线的;（２）ＰＴ开口三角形绕组接地端的判断方法及判据分析;（３）利用采样报告判断零序回路接线正确性的方法及判据的理论分析。