550kV瓷柱式断路器合闸电阻的研制

550kV瓷柱式断路器采用合闸电阻单元用于限制分合闸过程中产生的过电压,本文从合闸电阻的投入时间、热容量和耐压等多方面对其进行分析计算,计算结果表明：550kV瓷柱式断路器的合闸电阻单元设计合理,性能安全可靠。     

中压配网线路合闸过电压的抑制

结合电力系统配网线路运行参数特征,探究其对空载合闸时过电压的影响,利用在线监测及仿真模拟系统,重点表述断路器合闸时间。     

500kV断路器合闸电阻的测量分析

以500kV文都变断路器为例介绍断路器合闸电阻的基本结构与动作原理,并且简述测量合闸电阻的方法,对现场测量结果与厂家测量结果进行分析,最后说明在现场安装完毕后再对合闸电阻进行测量的必要性和现场用仪器进行合闸电阻测量的可行性。     

500kV断路器合闸电阻故障分析及应用维护

随着我国经济水平和科学技术的飞速发展,电力产业不断地进行发展。在日常生活中,人们对供电用电的质量要求越来越高。500kV断路器的组成中最重要的一个部分就是合闸电阻。合闸电阻在进行设计、制造试验的时候都对500kV断路器产生十分重要的影响。当断路器的合闸电阻发生故障时,不仅会在很大程度上降低相关器械的性能,还会对整个供电系统产生影响,降低电力系统的供电质量,发生短路断电等故障。本文主要对500kV断路器合闸电阻进行了故障分析,并对故障的应用维护进行一些研究和讨论。     

框架式真空断路器可靠性影响参数研究

断路器的分合闸同期性对断路器的可靠运行,甚至电网运行的稳定性都有很大的影响。本文以ZNWingdings 2cB@-12型真空断路器为研究对象,通过分析断路器运动过程建立框架的受力数学模型,利用动力学仿真软件ADAMS对断路器分合闸运动过程的动作机理进行分析,利用静力学分析软件ANSYS分析得到断路器框架的变形情况,得到影响框架受力的主要参数指标,有效指导了断路器框架的设计,根据力学仿真结果设计的断路器框架不仅满足断路器的机械特性要求,而且提高了断路器的分合闸同期性、机械寿命与工作可靠性。最后根据仿真结果投制试验样机进行厂内10000次寿命摸底试验,验证了本文设计的可靠性,该建模与分析方法为今后真空断路器的结构设计与功能优化提供了有益参考。     

500kV获嘉变电站LW13型断路器技术改造

500kV获嘉变电站的断路器系LW13-550型罐式断路器。在进行倒闸操作时,该断路器先后数次发生罐体内部故障,给电网的安全稳定运行造成了一定影响。对开关进行解体检查,发现断路器灭弧室的屏蔽环和罐体之间有明显放电点。分析了故障产生的具体原因,并介绍了断路器增加粒子捕捉器、提高绝缘裕度、增大压强、取消合闸电阻等改进措施,然后介绍了更换断路器的典型措施保障,保证了断路器改造工程的顺利完成。     

ZF6-1100kV断路器合闸电阻的计算分析

本文针对ZF6—1100kV断路器合闸电阻额定参数的选择加以计算分析和试验验证,结果证明其设计的合理,安全性。     

在线监测电机操作过电压的新方法

现在 ,电力系统中普遍采用真空断路器。但是开合真空断路器时易产生较大的操作过电压 ,对电动机的绝缘造成极大的危害。本文在分析操作过电压的产生原因及性质后 ,提出了一种新应用的方法 --有限元法来分析操作过电压对电机的绝缘影响 ,同时监测定子槽中绝缘介质的场强状况以此对电机内部绝缘状态实施在线监测和预测分析。     

220kV SF6断路器分闸不成功故障实例分析及处理措施

本文结合某SF6断路器分闸故障实例,对断路器故障进行了一系列的检测与试验,其中包括断路器的回路电阻检查、SF6气体检测、分合闸绝缘电阻检测等,同时借助X光透视试验,检查得出了断路器故障的根源所在,并提出了故障处理与解决方案。     

真空断路器在光伏发电系统中的瞬态响应分析

真空断路器在大规模光伏发电系统中有着重要应用,本文简要阐述了真空断路器的瞬态响应在光伏发电系统中的影响,分析了断路器操作产生的动态响应对高压变压器造成的损害,并对LC滤波模块在真空断路器操作时产生的过电压、重燃等动态特性的抑制作用进行了测试与讨论。     

Sequential phase energisation technique for capacitor switching transient reduction

The application of a sequential switching scheme for the mitigation of capacitor switching transients is presented. The method utilises neutral grounding impedance connected at the neutral point of the switched capacitor bank together with sequential pole switching. The neutral impedance is sized to minimise the open-circuit contact voltage of the capacitor breaker phases. Theoretical analysis of the proposed scheme has been carried out together with computer simulation. In addition, neutral impedance sizing criteria are presented in order to achieve minimal transient over-voltage caused by capacitor switching. The proposed method was found capable of reducing the transient over-voltage at the utility switched capacitor location to 1.07 and 1.12 p.u. at the customer load bus.     

Solid-state AC breaker with parallel switched capacitor circuits for microgrid system

ABSTRACT

In this paper, a novel solid-state AC breaker, based on double-paralleled switched capacitors controlled with complementary pulse width modulation technique, is proposed for transition of microgrid due to its advantages of low di/dt stress to power devices and controllable resistance features. The circuit topology of the breaker is based on parallel switched capacitors, its operating and control theory are analyzed in detail to show its advantage in theory. The equivalent impedance of proposed parallel switched capacitor circuits is up to the switching frequencies, and the proposed switch is suitable for seamless transition between the island mode and grid-connected mode to reduce the current shock by changing the switching frequencies. Simulation and experimental results verify the effectiveness and feasibility of the new AC breaker.     

基于图像序列短间隙真空开关电弧形态研究

研究短间隙真空开关电弧扩散运动特性对促进真空开关向高电压等级、大容量及智能化发展具有重要的意义。本文利用高速摄像机CMOS对真空开关电弧图像进行了采集并获得了序列电弧图像;分析了真空电弧燃烧过程扩散运动的机理及特征。综合数字图像处理技术,提出了基于二值背景差分法电弧图像燃烧扩散运动识别算法。实验结果表明:运用图像系列背景差分法可实现对真空开关电弧图像面积扩散区域进行检测,且通过计算可得到真空开关电弧在燃烧过程中不同时刻的扩散速度。     

Design of trip current monitoring system for circuit breaker condition assessment

A distributed system, which supports circuit breaker maintenance and asset management, is described. It uses a client/server architecture for propagating expert knowledge from switchgear maintenance experts directly to maintenance operatives for on-site circuit breaker condition assessment and diagnosis. Prior research in the field of distribution level circuit breaker condition monitoring has shown the trip coil of a circuit breaker yields a current profile that, when tripped, can subsequently be interpreted as an indicator of plant health. Exploiting existing circuit breaker test equipment, a centralised archive of asset condition is built from routine tests permitting experts to examine trends in the data and pass their definition of the operating conditions to personnel in the field. This provides diagnostic support to engineers in the field. The system is currently in use as the subject of a pilot study conducted by SP PowerSystems intended to improve its ongoing maintenance and asset management activities.     

真空断路器磁力驱动机构的静态磁路分析与计算

进行了真空断路器磁力驱动机构的磁路设计 ,并采用磁路法设计磁力计算软件 ,并就有关问题进行了讨论。     

Forming mechanism of the bipolar resistance switching in double-layer memristive nanodevices

To initiate resistance switching phenomena, it is usually necessary to apply a strong electric field to a sample. This forming process poses very serious obstacles in real nanodevice applications. In unipolar resistance switching (URS), it is well known that the forming originates from soft dielectric breakdown. However, the forming in bipolar resistance switching (BRS) is poorly understood. In this study, we investigated the forming processes in Pt/Ta?O?/TaOx/Pt and Pt/TaOx/Pt nanodevices, which showed BRS and URS, respectively. By comparing the double- and single-layer systems, we were able to observe differences in the BRS and URS forming processes. Using computer simulations based on an 'interface-modified random circuit breaker network model', we could explain most of our experimental observations. This success suggests that the BRS forming in our Pt/Ta?O?/TaOx/Pt double-layer system can occur via two processes, i.e., polarity-dependent resistance switching in the Ta?O? layer and soft dielectric breakdown in the TaOx layer. This forming mechanism can be used to improve the performance of BRS devices. For example, we could improve the endurance properties of Pt/Ta?O?/TaOx/Pt cells by using a small forming voltage.     

Dimensional effect of non-polar resistive random access memory (RRAM) for low-power memory application

The relationships between the resistive cell dimension and the related analytical parameters such as the forming voltage, set voltage, and reset current were investigated to implement high-density and low-power unipolar RRAM. It was shown that the formation process in unipolar switching is strongly related to the cell dimension in the sub-nm region, not only in terms of its vertical thickness but also of its horizontal length, using the numerical simulation method. With the optimal cell size having sufficient initial resistance and a low forming voltage, the achievement of the greatest feasibility of the high-density low-power RRAM will be further accelerated. A numerical simulation was performed using a random circuit breaker (RCB) simulation model to investigate the optimal resistive switching condition. The on/off resistance ratio increases as the cell area decreases at the sub-nm level, and these phenomena are explained in terms of the relatively large set resistance change in a very small area due to the conductive defect (CD) amount effect in the RCB network model.     

基于小波时频图和卷积神经网络的断路器故障诊断分析

高压断路器操动机构振动信号为非平稳性信号,蕴含着丰富的操动机构工作状态的信息,对操动机构工作状态的检验辨识具有重大意义。提出一种基于小波时频图和卷积神经网络的断路器故障诊断方法。对操动机构振动信号进行连续小波变换生成时频图(CWT),并对时频图进行统一压缩预处理;将预处理后的时频图作为特征图输入卷积神经网络AlexNet模型;通过对网络参数的调整,逐步改进网络模型,有监督地实现对操动机构故障状态的辨识诊断。结果表明,该方法能够有效地运用于断路器操动机构故障辨识诊断,与小波频带能量-RBF、小波频带能量-SVM的故障识别相比,故障识别准确率最高。     

Circuit breaker failure data and reliability modelling

The results from an extensive study of SF6 and minimum-oil circuit breaker failures in the Swedish and Finnish transmission systems are presented. The study includes 1546 breakers with a total operating history of 16 384 years. In the study, a detailed analysis of a specific SF₆ type of breaker revealed which parts caused the failures and an estimation of their hazard rates was made. A model of complete reliability for this type of breaker is presented, illustrated by presenting the operating and maintenance history of a shunt reactor breaker in the Swedish transmission system.     

一种用于声呐发射机的超级电容被动均压简易实用电路

超级电容器的性能不一致性会造成处于串联模式的电容组中个别电容器首先发生过压失效,进而加速整个储能组的失效。现有的均压电路一般工作在线性状态,电路也较复杂,不便于调试和生产。介绍了一种仅由5个元器件组成的简易、实用、高效的开关型被动均压电路,分析了其工作原理及均压特性。该电路在声呐发射机的储能电源中可长期使用,很好地保护了超级电容组。