基于继电保护隐性故障的电力系统可靠性分析

变电站继电保护运行面临着多种二次回路隐性故障,破坏了继电保护设备安全运行效率.面对早期电力系统改造存在的问题,要从可靠性角度展开深入分析,提出符合继电保护隐性故障防控的可行性对策,提高变电站继电保护作业效率.据此,本文结合电力系统可靠性标准,对继电保护隐性故障提出科学的处理方案.     

电力系统继电保护二次回路检修维护措施探讨

继电保护是对电力系统中发生的故障或者异常情况进行检测,从而发出报警信号,或者直接将故障部分隔离、切除的重要保护措施。如果连接继电保护的二次回路发生故障,将会直接影响到继电保护的功能,进而威胁到电力系统运行的稳定性和安全性,所以要加强对继电保护二次回路的检修和维护。文章首先阐述了继电保护二次回路检修维护的重要性及常见故障,然后对电力系统继电保护二次回路检修维护的措施进行分析,可有效降低继电保护二次回路故障的发生概率,为确保电力系统的安全稳定运行提供参考。     

继电保护二次回路干扰源及抗干扰措施研究

继电保护是对电力系统运行故障的及时排除、是对运行安全的评估,对确保电力系统安全、平稳的运行具有重要意义,做好继电保护能够为用户提供更高质量的用电,二次回路是继电保护中的重要环节,其运行情况受到多种因素的影响,容易引发各种安全隐患,本文从二次回路的基本概念情况出发,指出了二次回路抗干扰的重要意义,对二次回路干扰源进行了详细的分析,并提出了具体的抗干扰措施。     

电力系统继电保护二次回路的维护和检修

继电保护二次回路作为电力系统中的重要内容,其运行质量对系统的可靠运行具有直接影响,一旦出现安全或质量问题,则会造成无法估量的损失,因此做好继电保护二次回路的维护和检修至关重要.本文就对电力系统继电保护二次回路故障进行分析,并提出有效的维修措施.     

电力系统继电保护二次回路的维护与检修

电力系统具有整体性的特点,它的运行需要系统中各环节的相互支持.继电保护二次回路作为电力系统中重要的构成部分,其运行质量直接决定着电力系统运行的可靠性.但是,继电保护二次回路的运行仍然会发生质量问题和安全问题,所以要重视继电保护二次回路的维护和检修工作,以提升其运行的质量和水平.本文主要对继电保护二次回路进行概述,并分析了继电保护二次回路的故障,进而论述了继电保护二次回路的维护和检修措施,从而为电力系统运行的安全性和稳定性奠定基础,以此促进我国电力行业的发展.     

关于继电保护二次回路检修维护中存在的若干问题分析

随着我国经济的快速发展,人们的用电需求也在不断上升,同时也更注重用电安全及可靠性.通过继电保护装置的应用,能有效保护电力系统的运行与工作,降低故障发生率,并提升电力质量,可以说具有十分重要的现实意义.但是在继电保护装置的实际运行中,由于二次回路故障,极大影响到了继电保护装置及电力系统的正常运行.本文对继电保护二次回路检修维护中的若干问题进行了相应的分析,就怎样加强继电保护二次回路检修维护工作提出了几点意见.旨在加强电力系统运行的安全及其可靠性.     

基于继电保护二次回路的检修维护探讨

随着现代电力企业的不断发展,电力系统容量也在不断增大.作为电力系统运行的重要结构设备,继电保护良好性能的发挥将有效促进电力系统的正常运行.本文通过分析继电保护二次回路故障的破坏作用,着重介绍了二次回路的检修和维护措施.     

电力系统电气二次回路的常见故障及防范

在电力系统中,电气二次回路是经常见到的应用结构,在运行期间如果出现故障就会对电力系统的运行效率产生直接影响,因此有关技术工作人员需要详细的排查各种类型的故障,同时提出相应的措施对其进行处理。     

浅析辅助接点在电力系统二次回路中的应用及其常见故障

在电力系统中,辅助接点广泛应用于电力系统二次回路,在电力系统继电保护、调度自动化、监控等领域发挥着不可替代的作用。文章介绍了各类辅助接点在电力系统二次回路中的应用及其故障类型,通过列举现场实际案例重点分析了断路器/隔离开关辅助接点故障对电力系统二次回路的影响,并提出了降低断路器/隔离开关辅助接点故障率的方法。     

高压断路器故障诊断与检修分析

综合电力运行及研究相关经验,大致可将高压断路器故障分为两大类：①机械类故障;②源于二次回路的隐性故障。本文先对这两大类故障做详细的分析总结,提出检修对策,即在检修前要做初步调查,然后控制回路分析定位故障范围及故障点,再以辅助仪器仪表在断路器二次回路故障检修中的应用,最后结合长期积累经验检修故障断路器,做出科学合理的检修,保证电力正常运行。     

框架式断路器常见故障分析

框架式断路器本身的线路故障,各零件损坏老化,润滑原因,外界环境以及人为误操作等原因均可造成框架式断路器无法正常运行使用,本文具体分析了框架式断路器常见故障及原因,并给出实际工作中常用的故障处理方法,对电气工作人员具有一定意义,从而为电力系统的正常运行提供了保障。主要从指示灯不亮,无法合闸,非正常跳闸,操作不畅四个方面进行了具体分析。     

A Secondary Voltage Control Strategy for Transmission Level Interconnection of Wind Generation

This paper addresses implementation issues associated with secondary voltage control in a doubly-fed induction generator based wind farm. The effects of different system parameters on the performance of the control are considered, namely the short circuit ratio of the interconnection and the inherent communication delay between the wind park and the remote bus. In addition, a strategy for allocation reactive power requirements to each of the generators within the wind park is proposed. The system is developed and simulated for a wind park consisting of six wind generators connected to a typical transmission system. The paper proposes an optimal tracking secondary voltage control method developed to achieve effective voltage regulation, enhance the network voltage profile and provide optimal reactive power compensation to the interconnected power system. The performance of the controller is compared with secondary voltage control at one selected bus, primary voltage control and the optimal voltage profile obtained from the optimal power flow analysis. The performance of the controllers is tested for steady state operation and in response to system contingencies, taking into account the impact of communication time delays and short circuit ratio (SCRs). Simulation results are presented to demonstrate the capability of the controllers to provide the desired reactive power compensation and voltage support to the electric power grid.     

A micropower analog circuit implementation of hidden Markov modelstate decoding

We describe the implementation of a hidden Markov model state decoding system, a component for a wordspotting speech recognition system. The key specification for this state decoder design is microwatt power dissipation: this requirement led to a continuous-time, analog circuit implementation. We describe the tradeoffs inherent in the choice of an analog design and explain the mapping of the discrete-time state decoding algorithm into the continuous domain. We characterize the operation of a ten-word (81-state) state decoder test chip     

浅议智能变电站继电保护二次回路在线监测与故障诊断技术

当前,人们对于电能的需求越来越多,这就要求在电力系统的运行过程中切实有效的配备与之相对应的继电保护二次回路,以此来从根本上有效确保电力系统安全平稳的运行。     

输电线路在线监测系统可靠性提升方法研究

根据输电线路在线监测系统的特点和实际运行情况,对其常见故障进行了分类与分析,并建立了可靠性模型。在此基础上,提出了针对电路设计、机械设计、电源设计、标准化设计、实验验证等各个环节的可靠性提升方法。最后提出了针对输电线路在线监测系统的可靠性预计方法,并对所优化的系统进行了可靠性预计,得到了系统平均无故障工作时间（MTBF）的预计值,在一定程度上验证了可靠性提升方法的应用效果。     

微波固态功率系统控保电路的研究与设计

根据当前微波工程技术条件下的固态功率系统的常见故障,提出了相关控保电路的设计思路,进行了详细地分析和研究工作。依据上述设计思路,设计了一种新型的电源控制电路。对于微波固态放大器在使用过程中可能遇到过温、过工作比等故障,也进行了一些分析。简述了一种轻小型的射频脉冲功率测量电路,介绍了其中相关的一些器件。     

Catastrophic Failures in Power Systems: Causes, Analyses, and Countermeasures

Catastrophic failures of power systems are phenomena which occur with some regularity throughout the world. It is recognized that these cannot be prevented, although with the use of newer developments in power engineering, in communication systems, and in computer engineering it would be possible to reduce their frequency and their impact on society. Analyses of many blackouts point to some salient features which are common to most such events: power systems under stress because of high load levels or outages of important facilities, some initiating event-usually a fault, often followed by cascading effects due to unwanted operation of some protection systems. In particular, the role of hidden failures (HFs) in protection systems in propagating power system disturbances has become clearer with some of the recent research reported in the literature. This paper explores further the issue of HFs of protection systems and possible countermeasures. Regarding the countermeasures, adapting the protection systems so that they would change their operational logic from OR to a VOTING protocol has been discussed in the literature, and is well within the capability of present technology. Other hardware solutions, such as "Hidden Failure Monitoring and Protection Systems," have also been discussed in the literature. Most of these countermeasures will require intensive use of communication networks. Communication infrastructure will be utilized for real-time data transfer, as well as for slower speed data gathering tasks related to the condition of the power system. In this paper, we concentrate on the communication facilities and their applications for providing countermeasures against catastrophic failures of power systems.     

Soft switching resonant converter with duty-cycle control in DC micro-grid system

Resonant converter has been widely used for the benefits of low switching losses and high circuit efficiency. However, the wide frequency variation is the main drawback of resonant converter. This paper studies a new modular resonant converter with duty-cycle control to overcome this problem and realise the advantages of low switching losses, no reverse recovery current loss, balance input split voltages and constant frequency operation for medium voltage direct currentgrid or system network. Series full-bridge (FB) converters are used in the studied circuit in order to reduce the voltage stresses and power rating on power semiconductors. Flying capacitor is used between two FB converters to balance input split voltages. Two circuit modules are paralleled on the secondary side to lessen the current rating of rectifier diodes and the size of magnetic components. The resonant tank is operated at inductive load circuit to help power switches to be turned on at zero voltage with wide load range. The pulse-width modulation scheme is used to regulate output voltage. Experimental verifications are provided to show the performance of the proposed circuit.     

DC—DC正激变换器次级有源箝位电路

提出一种新型DC－DC正激变换器次级有源箝位电路。它一方面将储存于变压器漏感能量无损耗地转移到负载,另一方面有效降低了次级功率二极管电压应力。本文对其一个周期内工作原理及相关理论进行分析,并给出2.8kW DC-DC变换器实验结果及波形。