民用低压电路中性线断开事故的分析

从理论与实验两个方面,对民用低压配电系统中性线断线事故进行了分析,用实验数据验证了电器烧毁的原因,并说明了中性线的重要性。     

输电线路不平衡和断线张力计算与分析

2008年1月,我国南方地区遭遇大范围雨雪冰冻灾害天气,电网严重受损,电力供应中断,极大地干扰了经济社会发展和人民生活的正常秩序。文中通过对线路在遭遇极端天气情况时输电线路杆塔的断线、不平衡张力的求解,来指导输电线路杆塔设计,以提高杆塔抗冰雪能力,保证电网运行的安全。     

LFP系列变压器差动保护用电流互感器断线原理

介绍了南京南瑞继保电气有限公司生产的LFP系列变压器差动保护用电流互感器断线闭锁保护的原理。对其原理进行了分析，并提出了现场运行应采取的措施。     

一起因误拉电压互感器空气开关引起的跳机事故

电压互感器(TV)断线作为保护的辅助功能受到的重视程度往往不足.根据2006年某电厂发生的一起因为TV断线未闭锁保护引发的事故,分析各个厂家的TV断线逻辑,并给出一些具体的意见,以避免类似事故的发生.     

零序电流引起开关跳闸的分析诊断

本文介绍了河南中原煤电(集团)有限公司厂用系统403开关跳闸的分析、判断、检查处理过程,通过对零序电流的跟踪观察,结合备用分支开关零序保护的原理,查出零序电流的来源及开关跳闸的原因。本文详细阐述了从403开关跳闸,分析诊断到解决的过程,为处理类似的问题提供了很好的实践经验。     

发电机出口TV断线异常跳机分析和处理

分析了发电机出口电压互感器(TV)断线引起励磁故障异常跳机的案例,指出主要原因是高压熔丝性能劣化,二次电压缓慢跌落,励磁调节器未能自动切换至备用通道所致,提出了切实可行的解决方案。     

热电厂系统接地和PT断线的探讨

介绍了热电厂系统接地和PT断线的现象,指出了两种现象的区别,为电厂运行操作人员提供了系统接地和PT断线故障情况下的判断依据。     

隔离开关绝缘子断裂案例的分析与预防措施

介绍了对隔离开关的存在缺陷绝缘子的红外线检测过程。叙述了对已确认存在严重缺陷绝缘子,如何通过事故预想合理安排停电操作,避免因绝缘子断裂而引发事故。通过分析隔离开关绝缘子断裂的原因,提出了运行中应采取的预防措施,并总结了从此案例中取得的几点经验。     

B/S架构在线考试系统的断线续考功能的实现

随着教育信息化不断发展,基于Web的网络学习平台越来越多.在线考试系统是网络学习平台的重要组成部分.在线考试时由于多种原因,经常引发断线,致使考试过程中断.在线考试系统必须具备断线续考功能.文章介绍了B/S构架下ASP在线考试系统断线续考功能的工作原理及实现方法.     

Disconnected Processes, Mechanisms and Architecture for Mobile E-Business

With the tremendous advances in hand-held computing and communication capabilities, rapid proliferation of mobile devices, and decreasing device costs, we are seeing a growth in mobile e-business in various consumer and business markets. In this paper, we present a novel architecture and framework for end-to-end mobile e-business applications (e.g., point of sales). The architecture takes into consideration disconnection, application context, synchronization, transactions and failure recovery modes to provide mobile users with seamless and transparent access to business transactions and business-context specific data. In our architecture, we consider a novel business process design based on state-machines and event management to handle disconnection, resource limitations and failures. We designed, implemented and deployed a system for mobile e-business on clients (e.g., PDAs and PocketPCs) integrated with private exchanges and sell-side servers. The state-machine model with failure recovery mechanisms enables handling of one-to-many and many-to-one disconnections in large mobile e-business environments. The e-business framework on mobile clients is implemented based on J2ME, Webservices, and open XML standards. A detailed performance study of commerce transactions was done on different mobile client devices with diverse computing, memory and storage capabilities. We compare the performance of a purchasing application and the middleware on various devices such as PDAs and Laptops. We demonstrated that for small devices with limited capability the performance is reasonable. For devices with more computing capability, the response time is excellent.