并联Buck变换器均流电感接入方式的仿真研究

Buck变换器并联是工程上常用的增加电源容量的方法,采用在并联Buck变换电路中增加电感从而达到均流的目的。有两种方式,一是电感加在各Buck模块内部,二是电感加在主电路上。本文对并联Buck电路进行了原理分析以及仿真研究,仿真试验验证了两种方法均可不同程度地实现模块均流。     

交流变频调速再生制动问题的研究

针对电压型逆变器的变频调速系统讨论其再生制动的实现，提出了采用逻辑无环流控制方式控制整流器、有源逆变装置时有源逆变装置启动的原则，并设计了调速系统的框图。     

基于ACS800-104LC的大电机试验平台

本文介绍了一种新型的电机试验平台及控制原理。平台运用了变频调速,有缘整流及公共直流母线的能量回馈,能够适应不同类型的电机的多种试验,采用了ABB最新的ACS800-104LC水冷模块R8i,运用了直接转矩控制(DTC)和四象限运行原理。试验表明:试验平台运行稳定,试验精度高,有效地实现了能量回馈。     

基于DSP舰用全数字化控制逆变启动电源设计

舰船电站配备有交流电动滑油泵用交流电动机,对交流电机有直接启动和快速变频软启动的不同要求,本文给出了一种基于DSP全数字化控制的交流电机专用逆变启动电源设计方法。该逆变启动电源具有升压和逆变两级功率变换,升压电路采用变参数PI控制以提高动态响应能力,逆变电路具有输出电压闭环控制环节,并采用SVPWM调制技术提高直流母线电压利用率和改善逆变输出电压波形。本文对电源的系统结构、工作原理及控制策略进行了介绍,目前该电源已交付使用。     

多电平变换技术及其应用

介绍了多电平变换技术的发展,对多电平逆变器的电路结构以及控制策略进行了分析和比较,指出了其优缺点.最后介绍了多电平逆变技术在高电压大功率的变频调速、有源电力滤波装置和电力系统无功补偿等方面的应用情况.     

基于大功率储能模块的分布式船舶岸基供电系统

为实现一套岸基供电系统满足不同船型和不同用电容量船舶的岸基供电需求,提高岸基供电的可靠性、降低项目投资成本,对岸基变频电源的拓扑结构、插座箱的串联供电方式、应急电源的运行模式等进行研究,研发基于大功率储能模块的分布式船舶岸基供电系统.该系统采用集中整流和多路逆变的方式,实现一套岸电系统具备2种供电容量输出的能力;采用大...     

舰用中频机组带整流负载的建模与仿真分析

根据整流桥的运行状态,建立起中频机组带整流桥负载的数学模型,利用matlab/simulink中的电力系统模块(PSB)搭建系统的仿真平台.验证了非线性负载对中频电网的影响同时分析了旋转变频机组的滤波作用,为舰用中频电网的分析提供了有效的分析工具和试验参考.     

变频装置中直流电压利用率的分析

在船用变频装置中,直流电压利用率是衡量调制方法优劣的重要标志之一.提高直流电压利用率可以提高逆变器的输出能力.本文讨论了几种常见调制方法的直流电压利用率,并进一步分析了200kW变频装置三电平SVPWM调制的直流电压利用率.     

船用双闭环重复控制光伏离网逆变器研究

本文针对船用离网光伏逆变器负载特点提出了一种基于双闭环重复控制的逆变控制技术,即在dq坐标系下对系统进行解耦,并在电感电流内环和电容电压外环基础上附加一个重复控制环。双闭环控制可提高逆变系统的动态特性,重复控制改善了逆变系统的稳态精度。在Matlab环境下建立双闭环重复控制逆变系统模型,研制基于DSP28335的原理样机,仿真和样机实验结果表明该逆变控制策略具有良好的动静态特性和较低的谐波畸变率。     

基于1SDl548AI的IGBT驱动器设计

介绍了一种基于1SDl548AI的IGBT驱动器设计。对前级驱动电路、栅极电阻、过流和短路保护、补偿电容等进行了详细分析。试验证明该驱动器可用于大功率逆变场合,能很好地实现对IGBT模块的驱动和保护。     

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。