现代船舶电力系统鲁棒性研究

随着船舶动力系统增加,系统负载与推进器的非线性因素增多,影响船舶电网传输的稳定性,需要对船舶电力系统负载鲁棒性进行研究,以控制系统稳定性。本文建立船舶发动机负载与推进器的非线性模型,研究负载功率、电流及电压之间的耦合关系,在分析了系统鲁棒性基础上提出了一种基于Hamilton函数的船舶电力系统控制策略,对系统负载与推进器的非线性因素进行控制,最后对提出的策略进行仿真,结果表明其对船舶电网传输的稳定性具有很好控制作用。     

基于Hamilton理论的船舶电力控制系统

船舶全电化已成趋势,随之而来的是更大的负载设备功率,更高容量的船舶电站,这就对船舶电力安全和供电品质提出更高要求,也是对控制系统的挑战。船舶电力系统是一个非线性的复杂系统,且存在多个参数耦合的情况,传统线性控制效果不尽人意。论文在分析并建立以柴油发电机组为核心的船舶电站数学模型后,使用基于Hamilton理论的非线性方法对其进行研究和设计,最后给出适用于船舶电站的综合控制系统并仿真验证其性能。     

船舶能量管理系统PMS对策

船舶电力系统是独立电网,电气设备相互连接在一起,发电机和负载相互影响,对电力系统优化运行和控制的最基本要求是安全运行并且能量消耗最少。早期的能量管理是指为满足实际负载的功率需求,自动启动或停止发电机组。最近,许多先进的控制系统加入能量管理。以电力推进船舶的电力系统配置和船舶综合控制系统及其控制层次结构为例,对能量管理系统PMS的目标、组成、具体功能进行详细介绍。     

不同运行工况下船舶电力系统的负载响应特性研究

船舶电力系统经过上百年的发展,目前已经综合了电力推进系统、船载用电设备等,对于船舶的正常运行有非常重要的作用。随着船载用电设备的不断增加,一方面增加了船舶电力系统的供电压力,另一方面,对于某些非线性负载,可能会导致电力系统不稳定。本文研究的主要内容是不同运行工况下电力系统的负载响应,采用傅里叶变换等信号提取方式,结合船舶电力系统的数学模型,对不同运行工况下的电力系统负载响应进行分析与仿真,对于改善电力系统的负载响应特性有一定的参考价值。     

低频震荡特性在舰船电力系统控制中的应用

船舶电力系统是一个复杂的非线性系统,系统的动/静态负载与发电机形成强非线性的动态特征。本文针对电力系统低频震荡特性进行分析,研究舰船电力系统控制方法,并运用HHT方法给出船舶电气柴油机的转子运动方程和输出功率方程。通过HHT方法可减少干扰对系统的影响,确保整个系统正常运行及频率稳定性,提高船舶电力系统的暂态品质。     

船舶电站柴油发电机组H∞综合控制器的研究

船舶电力系统的稳定性主要取决于船舶电站柴油发电机组转速和电压的响应特性.转速和电压相互作用,对两者进行综合控制非常必要.本文将H∞控制理论应用于柴油发电机组综合控制系统的设计,将系统的性能要求转化为标准H∞控制问题.计算机仿真实验结果表明,本文设计的H∞综合控制器,能在充分考虑系统模型不确定性的情况下,有效地提高系统的动态精度和抑制扰动的能力,解决了转速和电压的综合控制问题,改善了船舶电力系统的稳定性.     

船舶柴油发电机转速控制系统设计

电力推进船舶通常采用柴油发电机组作为电力来源,通过电力驱动系统的电机。为了提高电力推进船舶的能源利用率,实现电力推进船舶的经济效益,针对船舶柴油机组的负载特性等进行柴油发电机的转速控制。本文首先建立柴油发电机的数学模型,结合柴发调速系统和PID控制技术,设计针对船舶柴油发电机的转速控制系统,并结合Matlab-Simulink平台进行了转速控制系统的仿真验证。     

船舶电力系统恒功率负载稳定性仿真研究

根据恒功率负载对船舶电力系统的稳定性的影响,探索影响系统稳定性的因素.通过分析恒功率负载的特性及实现方法并建立系统船舶电力系统带恒功率负载系统的Matlab/Simulink模型,研究了启动、突加、突减负载和短路等不同工况下恒功率负载对船舶电力系统稳定性的影响进行了验证.通过研究,确定了系统稳定性的因素,为未来船舶的电力系统的设计提供参考.     

基于非线性控制理论的船舶动力定位控制系统的数学模型

考虑到船舶的动态特性存在固有的强非线性以及非线性控制改善系统性能和鲁棒性的能力,将非线性控制理论应用到船舶动力定位控制系统的设计中,对某供应船的计算机模型进行仿真,仿真分析表明非线性控制系统是有效的.     

脉冲负载对独立电力系统运行特性影响

脉冲负载工作模式复杂,对于容量和惯性有限的船舶电网等独立电力系统的冲击和影响较大。为研究脉冲负载下独立电网运行特性以及脉冲负载不同参数对独立电网运行特性影响,通过在Matlab/Simulink平台建立柴油发电机组-整流器-脉冲负载模型,在仿真的基础上研究分析脉冲负载峰值功率、占空比、周期以及前端滤波电容参数对电力系统动态特性的影响规律。本文算例结果表明,脉冲负载工作时会对独立电网引起电力系统各参数的周期性波动,且波动程度与脉冲负载的工作模式有关：当峰值功率增大时,柴油发电机组的调压效果受到影响而频率近乎不变;当占空比D=0.5时,电力系统电压波动最大;周期增大时对励磁调压系统的影响变大且频率受脉冲负载的影响变大;同时合理增大滤波电容可以平抑脉冲负载引起的功率冲击。     

Errata

正In the paper"Influence of Fouling Assemblage on the Corrosion Behaviour of Mild Steel in the Coastal Waters of The Gulf of Mannar,India"in Vol.12,No.4,Page:509,References were lost,and the two authors’biographies were identical.The correct text is shown below.We apologize to the authors and our readers for any inconvenience caused by the errors.     

Journal of Marine Science and Application 2014 Sum. Contents

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第34届海洋、离岸及极地工程国际会议(英文)

正St.John's,Newfoundland,Canada,May 31-June 5,2015 OMAE2015 is the ideal forum for researchers,engineers,managers,technicians and students from the scientific and industrial communities from around the world to: meet and present advances in technology and its scientific support;     

联合作战计划和执行系统

全球指挥控制系统(GCCS)实施当前美国海军网络中心战信息基础设施的联合计划网络。联合作战计划和执行系统(JOPES)支持GCCS实现联合计划。JOPES有两类计划：时间不限的精密预案计划生成作战计划、方案计划或职能计划；时间敏感的危机行动计划生成作战命令或战役方案。前者在和平时期创建的作战计划是后者的计划基础，加速应付危机的能力。     

Eastbound or westbound ?

In terms of equal sailing distances, where is the inflexion when ships depart from ports in the Asian Continent to New York via Suez and/or Panama？
The answer is China South Port Group （Hong Kong, Shenzhen and Guangzhou）.     

Recent progress on wave induced loading measurements in warships

Recent measurements of wave induced hull strain and flexure in RN warships are presented together with the derivation of the current design criteria for extreme hull girder bending loads. The history of the development of the shipboard instrumentation used is given and recent developments to improve the quality and ease of analysis of the data are described. An unexpectedly high transverse asymmetry in the longitudinal strains measured in destroyers is shown to be the result of a combination of vertical and lateral bending in oblique seas. Finally recent theoretical comparisons between the loading of Deep-Vee hulls and conventional UK rounded bilge hulls are presented which demonstrate the higher loading experienced by this type of hull form.     

桥梁防撞设施物理模型试验

物理模型试验是预报防撞设施所受撞击力及优化设计方案的主要方法之一。结合杭州湾大桥柔性防撞设施及东海大桥独立式防撞体设计方案,阐述了船—防撞体撞击试验的基本原理、方法、试验方案及相关试验结果。提出了柔性防撞系统的优化方案。试验结果表明,该方案经济有效,可供预报类似桥梁防撞设施撞击力时参考。     

印尼某电厂码头水工建筑物设计

印尼某电厂项目码头水工建筑物包括码头、防波堤和护岸等主要组成部分。在该项目水工建筑物的设计过程中,综合考虑当地的自然条件、施工能力和材料来源等因素,不断优化结构选型和结构断面。根据不同使用要求,护岸分别采用直立式和斜坡式2种结构型式,推荐的设计方案节省投资、施工方便,可供同类工程设计参考。     

Impact of regulation on the performances of long-distance transport services: A comparison of the different approaches in Sweden and Norway

Despite the many socio-economic similarities between Sweden and Norway, differences in jurisdiction, organisation, cooperation, and financing of long-distance passenger train and coach services have led to the development of four distinctively different ways of serving the markets. This paper describes how the train and coach markets have developed in the two countries, with emphasis on regulatory and industrial structure and a couple of performance variables.Looking at passenger rail, both countries separated infrastructure from operation over a decade ago. However, while Norwegian rail is characterised by an almost monopoly supplier, rail services in Sweden are partly decentralised to the responsibility of county authorities and are widely subjected to competitive tendering. The rest of the network is about to be opened up for on-the-track competition. Swedish Rail (SJ) has spent the last decades consolidating its core business (passenger rail) and sold out its other businesses. In contrast, the Norwegian state rail (NSB) has expanded its business to become a major bus operator and property owner, with extensions also into the Swedish market.The coach industry was more recently deregulated in both countries. The Swedish coach market is dominated by privately owned companies operating services to and from Stockholm. In Norway, state-owned NSB is a major coach operator on medium distance routes, and is also the largest partner of Nor-Way Bussekspress which totally dominates long-distance coach services. Further, the Norwegian coach market is characterised by cross-ownership and cooperation which has enabled an extensive route network which covers most of Norway.We find distinct differences in achievements in the two modes and in the two countries. Swedish rail services have succeeded in winning market shares and in renewing and developing both infrastructure and service levels to a greater extent than the Norwegian model. On the other hand, the Norwegian coach market seems to be more developed and efficient compared to its Swedish counterpart.The paper concludes with a discussion on the possible links between the different approaches and the performance observed, with the aim to stimulate further and more detailed research on some important issues.     

开放式数据挖掘系统模型

目前国内已经出现了少量的数据挖掘相关产品。国内数据挖掘软件无论从数量还是质量上比较，都与国外软件存在着较大的差距。随着数据仓库技术的普及，数据挖掘应用的需求越来越强烈，如何缩短这种差距，研发数据挖掘软件产品成为国内业界的一个重要问题。通过引用目前国际通用数据挖掘标准技术来构建开放式的数据挖掘系统模型，该系统模型从可扩展性、可重用性、易用性等方面得到了加强。