配出中性导体的IT系统负载不平衡分析

阐述了配出中性导体的IT系统特点以及与TN系统的区别,针对负载不平衡,从负序电压不平衡度、畸变率、电压波动、以及中线电流比等角度对配出中性导体的IT系统进行了分析,同时与TN系统进行对比。搭建了原型系统并进行测试,数据分析表明了IT系统配出中性导体的可行性,为进一步研究打下基础。     

IT系统绝缘监测技术研究综述

绝缘监测装置是IT系统保持高供电可靠性的重要条件。总结了现有绝缘监测技术的基本原理,分析了各中绝缘监测方法存在的问题;并对国外绝缘监测技术的发展进行了介绍。得出低压IT系统对地阻抗模型以及新型故障诊断方法方面的研究能够促进IT系统绝缘监测技术发展的结论。     

船舶低压IT配电系统的特点及应用

介绍了国际电工委员会对于IT、TT、TN配电系统的定义。根据IT、TT、TN三种配电系统的接地型式不同,比较了IT系统与TT及TN配电系统的特点,分析归纳了IT配电系统供电连续性较高、供电安全性较好的优势以及供电灵活性较低、设备绝缘要求高的缺点。在此基础上,通过对船舶IT配电系统的应用案例,探讨了IT配电系统发生第一次和第二次接地故障时需采取的保护措施,介绍了船舶IT配电系统的设备配置。     

舰船直流电网绝缘状态监测装置设计

舰船直流网络绝缘状态监测装置是保障舰船直流电力系统安全，实时掌握直流供电系统网络绝缘状态的所必须的设备。以往对直流网络绝缘监测的主要采用人工方式进行测量，人员劳动强度大，测量过程繁杂，不能及时掌握绝缘状态信息，察觉系统隐患。因此本文完成了直流网络绝缘监测系统的设计，通过三电压法和附加电源法完成不同直流网络绝缘电阻的测量．并实现故障支路的定位，最后确定了装置数据采集系统和通信系统的实现方案。     

船舶电站绝缘监测系统的原理研究与硬件设计

船舶电站系统的复杂程度的增加,对船舶电站绝缘监测系统提出了更高的要求。本文研究了船舶电站绝缘监测系统的原理,首先讨论船舶的电站技术,着重分析了船舶电站的发展及其基本参数;研究了绝缘监测技术,分析了直流绝缘监测技术和交流绝缘监测技术;探讨了船舶电站的绝缘监测技术。本课题的研究对于推动我国船舶电站绝缘监测系统的发展有着重要的意义。     

船舶电网绝缘监测系统的设计与实现

介绍了PROFIBUS-DP现场总线在绝缘监测控制系统中的应用。系统采用现场总线技术与PLC技术,根据船舶电网的运行状态制定相应的绝缘监测策略。当发生电网绝缘故障时,可实现故障支路的快速、准确定位,极大地提高了绝缘监测的效率和可靠性。     

三相四线制IT系统绝缘监测技术方案研究

三相四线制IT系统发生中性线接地故障前后通常不引起系统电气信号的变化,若再发生另一线接地,就会出现短路跳闸,难以保证供电连续性。针对这一问题,提出三相四线制IT系统绝缘监测技术方案。使得三相四线制IT系统在发生接地故障时能及时排除,以保持其供电连续性及可靠性,通过理论分析及建模仿真,验证了其正确性及可行性。     

船舶交流电网绝缘监测及故障定位系统开发

针对传统船舶电网绝缘监测装置可靠性不足、受泄漏电容的影响较大、测量范围较窄、测量准确度不高等问题,以船舶IT交流供配电网络为研究对象,建立一种能够实时监测整个电网系统对地绝缘值与泄漏电容值,实现实时故障定位的系统,并结合Hausdoff距离算法进行容错计算.结果 表明:该系统可实时监测船舶电网的绝缘状态,并实现故障线路的准确定位,为操作人员保养设备和抢修设备提供最及时、最准确的判断信息,能够做到尽快排除故障,恢复供电,保证机电设备随时处于备航状态.     

高潭口泵站计算机监控保护系统设计

简述高潭口泵站的概况及计算机监控保护设计的主要原则,给出了系统的总体设计方案,并以主机保护为例着重介绍了泵站微机保护系统特点。该保护系统设计安全、可靠、方便、实用。     

船舶电力系统直流网络绝缘状态监测系统研究

本文讨论了船舶电力系统直流网络绝缘状态监测研究的需求和必要性，分析了目前国内主要船舶的直流网络现状及其绝缘监测需求，讨论了国内外绝缘监测技术现状，最终确立了适应我国情况的直流网络绝缘监测设计方案，并通过仿真验证了其测量原理的正确性。     

Hysteretic damping of soils for well conductor fatigue analysis

The fatigue assessment of a well conductor is a critical design task during offshore exploration and development of hydrocarbons. In recent years, major progress has been made towards the modelling of soil-conductor interaction. Upgraded soil-conductor interaction springs (i.e., p-y curves) and damping models are developed and are gaining acceptance by the industry. However, there is a general lack of simplified procedures to incorporate the soil damping into the time-domain structural analysis of a wellhead system. Thus, the motivation of this paper is to close this gap by proposing a simplified procedure for incorporating the soil damping in the well conductor time domain analysis. The procedure is generic and allows for convenient adoption of alterative p-y spring and damping models. Design charts for equivalent soil system damping ratio versus the lateral deflection of the conductor are developed through parametric analyses based on representative wellhead configurations with typical soil strength profiles in the Gulf of Mexico to facilitate practical design.     

低压配电系统单相接地选择性切除方案研究

本文结合目前飞速发展的单片机及高精度快速采样技术,提出低压配电系统单相接地故障选择性切除的方案。通过理论分析及建模仿真验证了方案的正确可行性。     

大型深水导管架井口导向同心度的计算方法

描述了一种大型导管架井口同心度的计算方法，用最小二乘法将各层井口中心点坐标拟合成一条空间直线，再计算各个井口导向中心到拟合直线的距离，从而准确地判断井口是否偏离最佳拟合直线。利用VBA编程软件，可以非常快速地计算出结果，大大提高了效率。     

基于BP神经网络的渔港评估指标体系简化

为使渔港管理部门在进行渔港初步评估时节省人力、物力,对渔港评估指标体系进行简化,应用BP神经网络进行渔港评估。简化后的指标体系繁简适中,科学合理,结果符合实际,可供有关部门对渔港进行管理决策时参考。     

转子空内冷励磁绕组的损耗和漏感计算

转子空内冷汽轮发电机中的励磁绕组导条开有轴、径向通风孔，导条轴向截面突变导致电流分布不均匀，这使得以截面电流均匀分布为前提的传统方法计算出的导条损耗精确度不高，且径向开孔后导条的槽漏感无法用传统方法计算。本文采用有限元法计算了导条的损耗和槽漏电感，并与传统方法进行了比较，说明了采用有限元法进行计算的必要性。     

Experimental and finite element analysis of fatigue strength for 300 mm2 copper power conductor

The fatigue strength of a 300 mm² stranded copper conductor was investigated experimentally and by finite element (FE) analysis. An analytical model was also developed and validated. Wires taken from the outer layer of the conductor were fatigue tested in tension–tension loading and compared with similar data for wires taken from a 95 mm² conductor. The wire cross section was deformed due to the compacting process that was applied during fabrication. When corrected for stress concentrations due to the deformation the data for the two sets of wire fell within the same scatter-band. Full scale testing was carried out in a specially designed rig with constant tensile load and reversed displacement controlled bending with a fixed curvature variation. The loading is a simulation of the loading of a power cable hanging from a floating vessel through a bellmouth. Conductors were tested in two states; dry and lubricated. A finite element model was established for the copper conductor. The model was formulated by a combination of elastic beam and beam-contact elements that included the effects of friction. The effect of local bending due to contact forces was included in the model. Two contact conditions were investigated; the point (trellis) contact between adjacent layers of wire and the inline contact within each layer and between the first layer (centre wire) and the second layer. The FE model was validated by a calibration test of a full scale conductor, and by sensitivity studies varying the size and the number of elements of the model. Fatigue analysis of the conductor was carried out, based on the S–N curve for individual wires. Taking into account the effects of friction and local bending, agreement was obtained between predicted and experimental fatigue strength of the conductor, for the FE model as well as the analytical model.     

Implementation of an executable business process management model for the ship hull production design process

The shipbuilding industry has adopted IT convergence as a new engine for growth encompassing conventional production know-how and economies of scale. Brand new solutions for enterprise IT, such as three-dimensional (3D) computer-aided design (CAD) systems, enterprise resource planning systems, and product lifecycle management systems have been adopted and customized to shipyards and contribute to productivity enhancement. As part of IT convergence in the shipbuilding industry, we examine the adoption of business process management (BPM) for the ship hull production design process. Ship hull production design, a process-based task, requires the most man-hours among all ship design processes and is directly coupled with ship production; thus, improvements in this task can contribute hugely toward enhancing productivity. First, we explain the concept of the executable model, which is an essential condition for executing defined processes in a business process management system (BPMS). In addition, we analyze the hull production design task and use this as the basis of a process to build executable BPM models. Thus, we present detailed implementations and the expected effects for the BPM execution of the hull production design process. The executable BPM model of the hull production design process is implemented using Bonita Open-Solution 5.5, a representative open-source BPMS.     

新型自动插拔低架滑触线轮胎吊油改电系统

介绍轮胎吊低架油改电技术的发展以及各种自动插拔方案,并进行系统比较,阐述连云港新东方集装箱码头选用的新型自动插拔低架滑触线轮胎吊油改电方案的设计内容、实施情况和使用效果。     

低压船舶岸电供电系统方案研究

由于港口码头和船舶的供电系统不相互兼容。提出了低压船舶岸电三相四线制IT系统的方案,使得船舶靠港时能直接接用岸电,以降低其供电系统运行成本,提高系统利用率。且可以降低船舶对周边环境的污染,借助于先进的绝缘监测技术使得该系统能可靠运行。通过实验模型的建立及仿真分析,验证了本文提出的供电系统方案的正确性和可行性。