东北电网通信传输网管整合方案

针对东北电力通信网管系统存在的不足,讨论网管系统整合方案。该方案可以解决网管系统网元脱管问题、网管数据备份问题,同时也解决了环境美观问题。方案中既有各生产厂家网管系统的共同点,也有不同点,确定了以各厂家网管系统为各自平台进行统一整合,整合后的网管系统极大地提高了运行可靠性。     

220kV备自投装置外部闭锁回路设计问题

通过对备自投外部闭锁回路设计的阐述,分析外部保护永跳动作误闭锁备自投及线路检修分合开关时启动手跳继电器误闭锁备自投的原因,提出改进措施。实践证明其正确有效。     

并联螺杆压缩机制冷系统的研究

在制冷系统中两台并联压缩机中只能运行任一台压缩机,交替运行并相互备用,均衡磨损,保证机组系统的可靠性。     

CARR供电系统概述

CARR供电系统主要由中压、低压、直流、备用和应急供电子系统组成,简述了中国先进研究堆(CARR)供电系统的总体特点、主要功能和设计准则;详细地介绍了各子系统的组成、功能和特点等。CARR供电系统的工程设计,遵循了相关的核安全法规和工业标准的要求,达到了系统所承担的运行功能和安全功能。     

Uncertainties and quantification of common cause failure rates and probabilities for system analyses

Simultaneous failures of multiple components due to common causes at random times are modelled by constant multiple-failure rates. A procedure is described for quantification of common cause failure (CCF) basic event probabilities for system models using plant-specific and multiple-plant failure-event data. Methodology is presented for estimating CCF-rates from event data contaminated with assessment uncertainties. Generalised impact vectors determine the moments for the rates of individual systems or plants. These moments determine the effective numbers of events and observation times to be input to a Bayesian formalism to obtain plant-specific posterior CCF-rates. The rates are used to determine plant-specific common cause event probabilities for the basic events of explicit fault tree models depending on test intervals, test schedules and repair policies. Three methods are presented to determine these probabilities such that the correct time-average system unavailability can be obtained with single fault tree quantification. Recommended numerical values are given and examples illustrate different aspects of the methodology.     

转换开关不完全可靠的冷贮备系统可靠性的置信限

在实际问题中,贮备系统的转换开关也可能失效。本文在元件寿命为指数型,开关寿命为0—1分布,成功概率为p(已知或未知),对试验数据,按一、二阶矩相等的拟合原则,综合折合为系统的伪成败型数据(N,S)的方法,给出了计算系统可靠性近似置信下限的公式。文中还就开关寿命为指数型的情况作了讨论。     

一种自适应的企业级容错系统的建构

为满足对安全关键领域日益增长的可靠性需求,本文提出一种自适应的基于Cluster技术的企业级容错解决方案。该方案可根据监控状态数据,自适应切换双机热备份与双机对等备份模式,以达到从整体上提高系统可靠性的目的。     

商业应急照明概述

针对近年来出现的商业建筑向高层及大型化发展的趋势,结合对国家规范及一些行业标准的学习,提出了商业应急照明的设计要点.指出商业一、二类建筑的应急照明应按一级负荷供电,应急照明也应作为正常照明的一部分来使用.对应急照明中的疏散照明、备用照明的照度要求、转换时间、灯具布置作了较详尽的分析.最后给出了大型商场统一经营及多元化经营时的应急照明控制方式.     

Linux下休眠功能的软件实现

对高级电源管理进行了阐述，介绍了Windows2000下休眠功能，指出了其不足，详细解释了如何在Linux下用软件实现休眠功能。     

Estimation of membrane hydration status for standby proton exchange membrane fuel cell systems by complex impedance measurement: Constant temperature stack characterization

Fuel cell-based backup units are characterized by long standby periods but they must be ready to start at any instant in the shortest possible time. In the case of low temperature proton exchange membrane fuel cells, the estimation of the hydration status of the fuel cell's membrane during standby is important for determining the cell's ability to perform a fast and safe startup. In this article, non-conventional electrochemical impedance spectroscopy (EIS) is suggested as a method to estimate the membrane's hydration status. The proposed technique differs from standard EIS in that the current through the fuel cell cannot contain a DC component, since hydrogen is absent. A 56-cell fuel cell stack has been symmetrically fed with air, whose temperature and relative humidity were controlled, and its complex impedance was measured at different frequencies and for different values of relative humidity at constant temperature. Power regression models were applied to the data, and the relationships between complex impedance and relative humidity were found. The results showed that the proposed technique is a viable way for estimating the membrane hydration status of a fuel cell stack during standby. Moreover, the most suitable frequency values at which the measurements should be performed are given.