电力系统高压真空断路器分合闸线圈的烧毁原因及预防策略研究

在对电力系统高压断路器分合闸线圈烧毁的原因进行分析时,可以从投切故障等方面着手。通过研究断路器合闸线圈故障以及操作机构二次回路故障,对分合闸线圈烧毁的问题进行深入分析。本文通过分析影响分合闸线圈烧毁的各种因素,提出了有效维护分合闸线圈烧毁的各项举措。     

高压真空断路器分合闸线圈的烧毁原因及预防策略

在应用真空断路器时经常会发生合闸线圈被烧坏的问题。文章从合闸回路的原理入手,对闸线圈烧毁进行举例并分析,进而提出防治合闸线圈烧毁的措施,以供相关人员参考。     

断路器防跳回路常见问题分析与整改措施

该研究分析了断路器防跳回路的原理及防跳功能的实现方式。针对工程应用中断路器防跳回路常见的问题,包括机构防跳回路设计不合理、合闸监视回路与防跳回路配合不当和跳闸保持继电器未能可靠动作等,分析了产生问题的原因,并结合现场实际情况提出了相应的整改措施,以期为今后现场作业人员、设计人员提供了切实可行的参考方案。     

基于就地数字化的断路器控制系统研究

高压断路器是电力系统的关键开关设备,其运行状态的实时准确掌握是保障其正常发挥功能和较长使用寿命的必要手段。研究了一种基于就地数字化的断路器控制系统,基于多维参量,断路器电气控制回路,断路器控制智能分析模块,通过断路器本体汇控柜里的智能汇控装置采集断路器操作过程的暂态一次电流及恢复电压波形、断路器的操作振动声纹波形以及分合闸线圈的操作电流波形;由就地数字化平台根据断路器操作机构的机械、电气等机理模型对这些波形进行综合识别和关联分析诊断,返回就地智能汇控装置进行断路器状态更新,以便现场人员随时可以在就地掌握断路器当前的状态,并对断路器分合闸控制就行分析,确定断路器状态为正常后可正常进行断路器电气控制的实现。     

保护装置重合闸误动作问题研究

自动重合闸装置是用来实现线路故障跳闸后开关自动重合,提高供电可靠性,当重合闸充电时间与开关储能时间不相匹配时,将造成开关多次重合,会对断路器本体及系统造成严重影响。本文从实际出发分析了LFP-941D保护装置重合闸误动作原因,并引入“虚拟压力接点”实现了断路器弹簧正在储能时,重合闸不能充电,储能完成后重合闸开始充电,有效解决了LFP-941D重合闸误动问题。     

基于FPGA的高压断路器分合闸参数检测系统研究

该文提出了一种基于FPGA的高压断路器分合闸线圈电流及分合闸时间检测系统的设计方案。该方案以FPGA为控制核心,通过AD芯片对断路器分(合)闸线圈电流信号的进行采集,并通过FIR滤波器对采集到波形进行数据处理,实现高压断路器线圈电流-时间特性检测方法。实验结果证明,该方案可实现断路器合(分)闸线圈电流和时间特性的检测,为及时发现故障提供重要依据。     

高压断路器分合闸线圈烧毁原因分析及应对措施

高压断路器在分、合闸过程中,常会出现分、合闸线圈烧毁现象,作者结合多年来的故障处理经验,对线圈烧毁的原因进行了分析,并提出了应对措施。     

基于有限元方法的断路器故障模拟分析

高压断路器作为在电力系统中起到保护和控制作用的重要关键设备,诊断其工作运行状态对于维护电力系统的安全运行有着重要意义。高压断路器分合闸电磁铁线圈的电流信号可以不同程度地反映断路器的各种故障,通过建立断路器电磁铁有限元模型,对线圈接触不良、线圈短路、电压波动故障时的线圈电流信号进行模拟分析,根据分析结果可识别故障类型。最后,可针对性对电磁铁故障进行检修,提高维护工作效率,降低断路器故障发生率。     

基于线圈电流的牵引变电站直流断路器状态监测与诊断研究

直流断路器在系统设备入网或者退网时起到开关转换的控制作用,是电力系统的关键设备之一。研究牵引变电站直流断路器的合分闸线圈电流与直流断路器状态的联系,实现对直流断路器的状态诊断。首先利用霍尔电流传感器采集分合闸线圈电流波形,然后分析了直流断路器分合闸过程线圈电流的变化机理并确定以电流拐点的时间(t1/t2)和电流值(i1/i2)作为诊断的特征值,接着对采集的电流波形进行15kHz低通滤波去噪后采用电流包络法提取分合闸线圈电流信号中特征值,最后随机划分80%样本为训练样本,20%为测试样本,通过SVM支持向量机对模拟的7种不同状态进行诊断。诊断结果表明,通过分析分合闸线圈电流的特征值能够实现牵引变电站直流断路器的状态监测与诊断。     

交流高压真空断路器永磁机构控制器的设计

针对现有的永磁操动机构真空断路器控制电路采用2个直流接触器切换储能电容对分、合闸线圈供电存在控制时间不准确、分散性大、难以与高压综合保护器联动、功耗多、成本高等问题,提出了一种交流高压真空断路器双稳态永磁机构控制器的设计方案,详细介绍了该控制器的硬件电路和软件设计。该控制器具有完整的永磁机构控制单元,可实现合闸、分闸、闭锁以及欠压延时、欠压保护等功能,并为远程通信提供技术基础,在断路器技术参数范围内可保证安全、可靠运行,并可在额定参数范围内进行频繁操作。     

中置式高压电容器柜改进设计

分析了南屯煤矿白马河风井变电所高压电容器柜原设计方案存在的问题,并对其进行了改进设计:选用适用于容性负载的真空断路器;添加放电线圈,并将放电线圈与电容器直接并联,使放电线圈与电容器组成一个完整的放电回路;添加接地开关,接地开关既有机械闭锁又有电气联锁,操作方便,安全性高。实际应用表明,改进设计后的高压电容器柜功能更加完善,更加安全、可靠。     

基于改进串联合闸电阻的变压器励磁涌流抑制研究

在利用合闸电阻抑制变压器轻载或空载合闸时产生励磁涌流的基础上,提出一种在合闸电阻上串联适当电容器的改进方法。该方法在原有的合闸电阻上串联电容,通过适当选取电容的容值,以减少励磁涌流的大小,加快励磁涌流的衰减速度。将该方法与分相合闸技术相结合,可最大程度实现变压器励磁涌流的抑制。仿真实验结果验证了该方法的可行性。     

一种基于快速闭合的真空断路器短路电流限流器

本文提出一种新型的带串联补偿的短路电流限制器,它主要由可快速闭合的真空断路器、电容和电感元件及无功补偿回路组成,与电容并联的快速开断的真空断路器控制着正常时的串联补偿或短路的限流,通过仿真及样机实验,证明了此系统具有良好限流保护特性。     

基于S7-300 PLC的矿井通风机不停风自动倒机系统设计

针对高瓦斯突出矿井进行主通风机倒机时,在短暂的停机时间内仍会出现瓦斯超限现象的问题,提出了一种基于S7-300 PLC的矿井通风机不停风自动倒机系统的设计方案。该系统采用增加对空旁路风门来启动备用通风机的方案,即在主通风机停止前先启用备用通风机,通过主、副风门开度的配合,保证倒机系统风量的稳定。实际应用表明,该系统可有效保证不停风倒机过程的安全。     

一种新型瞬变电磁发射机去过冲系统设计

针对瞬变电磁发射机发射电流过冲造成探测盲区的问题,提出了一种新型瞬变电磁发射机去过冲系统设计方案。该方案在发射线圈两端并联一个优化的RLC二阶电路,在发射电流下降到接近零时接通该电路,让发射电流按指数衰减,从而有效去除电流过冲。仿真与实验结果表明,该方案能够去除发射电流的过冲振荡,减小探测盲区。     

Detecting Loop Closure with Scene Sequences

This paper is concerned with “loop closing” for mobile robots. Loop closing is the problem of correctly asserting that a robot has returned to a previously visited area. It is a particularly hard but important component of the Simultaneous Localization and Mapping (SLAM) problem. Here a mobile robot explores an a-priori unknown environment performing on-the-fly mapping while the map is used to localize the vehicle. Many SLAM implementations look to internal map and vehicle estimates (p.d.fs) to make decisions about whether a vehicle is revisiting a previously mapped area or is exploring a new region of workspace. We suggest that one of the reasons loop closing is hard in SLAM is precisely because these internal estimates can, despite best efforts, be in gross error. The “loop closer” we propose, analyze and demonstrate makes no recourse to the metric estimates of the SLAM system it supports and aids---it is entirely independent. At regular intervals the vehicle captures the appearance of the local scene (with camera and laser). We encode the similarity between all possible pairings of scenes in a “similarity matrix”. We then pose the loop closing problem as the task of extracting statistically significant sequences of similar scenes from this matrix. We show how suitable analysis (introspection) and decomposition (remediation) of the similarity matrix allows for the reliable detection of loops despite the presence of repetitive and visually ambiguous scenes. We demonstrate the technique supporting a SLAM system driven by scan-matching laser data in a variety of settings. Some of the outdoor settings are beyond the capability of the SLAM system itself in which case GPS was used to provide a ground truth. We further show how the techniques can equally be applied to detect loop closure using spatial images taken with a scanning laser. We conclude with an extension of the loop closing technique to a multi-robot mapping problem in which the outputs of several, uncoordinated and SLAM-enabled robots are fused without requiring inter-vehicle observations or a-priori frame alignment.     

Correspondences between input estimation and feedforward control

A correspondence between input estimation (deconvolution) and feedforward is discussed from a polynomial point of view. Optimal estimation and feedforward control filters are derived from a spectral factorization and a polynomial equation. Simple loop transformations are used for transforming one problem into the other. The close relationship cannot be explained by the well-known duality between optimal state estimation and feedback control. Instead, it rests on the fact that both the problems discussed are open loop. They can be seen as two interpretations of one underlying design problem. Several other open-loop problems can be described in this framework.     

矿井主通风机不停风切换方案研究

针对矿井主通风机切换过程中发生瓦斯超限的问题,分析了现有的主通风机切换方案,指出实现主通风机不停风切换的关键是要避免运转风机和备用风机在切换过程中同时运行在额定状态下;提出了一种矿井主通风机不停风切换方案,并提出可采用PLC实现该方案的自动控制;最后对该方案的供电系统要求及目前煤矿实现该方案时面临的主要问题进行了分析,认为该方案具有较强的可行性。     

Optimal capacitor allocation in power systems

Static capacitors are installed at specific locations in large power systems for minimising power losses and to ensure quality of the supply system. It has been found that the number of units in each capacitor bank can be considerably reduced by suitable choice of transformer tap settings and generator voltage magnitudes, thereby reducing the cost of installation of capacitors. This paper presents an efficient method for finding the optimal values for the number of units in each capacitor bank and their locations for the purpose of reducing power losses and for ensuring the quality of the supply system. This is accomplished by optimal allocation of all reactive power sources in the system in a coordinated fashion by varying the number of units in each capacitor bank and generator voltage magnitudes and transformer tap setting positions.The problem is formulated as an optimisation problem with the objective function representing the revenue resulting from reduction in power losses, taking into account the cost due to interest and depreciation on the static capacitor installation and the constraints based on physical and technical limitations on the system. The problem falls in the category of Mixed Integer Linear Programming (M.I.L.P.) and is solved by decomposing the problem into two smaller subproblems viz., a pure integer programming problem in binary variables and a linear programming problem. The solutions of these subproblems are coordinated to get the solution of the original problem. Very fast convergence is obtained by preventing zigzagging of the solution about the optimal point. All these result in considerable savings in computer time and memory. The proposed model has been applied to sample systems and the results presented and discussed.