晶体管可控相复励励磁系统

励磁系统是船舶电站的主要组成部分,船舶电站的可靠性、稳定性和电能质量,在很大程度上取决于励磁系统的性能和它运行的可靠性。船上不可控相复励励磁系统因其简单、工作可靠、动态性能好,因此用得比较多,但静态调压指标比较差,不能满足要求高的船上应用。采用控制相复励变压器耦合能力的可控相复励励磁系统与可控硅励磁系统,静态调压指标高,但它们的共同缺点,是当电压较正器出现故障时将使电压不能恒定,可靠性差,而且可控硅励磁系统因硅元件易损坏,电磁干扰大,影响了它在船上的使用。因此,早在1974年704所研制了TZ-F型可控相复励励磁装置,它是由相复励电磁迭加具有电压曲折绕组的谐振式励磁和可控硅直流侧分流,即采用可控硅斩     

可控硅励磁恒压装置原理及其故障分析

本文对船用可控硅励磁恒压装置作为一个整体进行系统分析,进而讲述各部件的作用原理、关键件的调节要点,提出故障解决办法,供船舶电气管理人员参考.     

小水电站可控硅励磁故障维修经验浅谈

小水电站TKL可控硅励磁装置组成,工作原理,常见故障现象,故障原因分析,提出维修方法。     

基于PLC技术的RTG电控系统改造

为了兼顾集装箱业务,池州港泥洲港区购置了1台二手轮胎式集装箱门式起重机(RTG).原机金属结构及主要执行机构状态良好,但电控系统采用老式继电-接触控制系统,线路老化,故障频发,且采用自整角机和可控硅励磁装置进行速度调节,可靠性等方面已不能满足使用要求,因此对原机电控系统进行了改造.采用日本立石电机公司的OMRON CQM1H(CPU51)进行整机电气控制,取消原自整角机给定及可控硅励磁装置,用CQM1-DA021模拟量输出模块代替原给定,同时加装英国EUROTHEM DRIVE.LTD产514C直流驱动器作功率放大,以驱动直流发电机励磁绕组.此外,为了减少维修量,方便故障查找,加装日产MT506触摸屏,且更换了部分原器件和电缆.     

晶体管恒频恒压逆变器

以稳压变压器作为输出元件的恒频恒压晶体管逆变器具有输出电压和频率稳定、逆变效率高、电路简单、特性优良、无干扰、工作可靠等优点。实际使用表明,其技术经济指标均优于可控硅逆变器和换流机组。     

简析船舶电站相复励装置对各种扰动量的补偿

本文通过推导各种相复励装置等值电路的励磁电流表达式，分析励磁电流表达式，逐步揭示出各种相复励线路对发电机运动过程中所遇到的各种扰动量的补偿情况。     

基于DSP的变流机组励磁调节研究

本文分析了目前利用模拟电路控制的舰船中频变流机组励磁调节器存在的不足。设计了基于DSP的变流机组励磁调节,搭建了励磁调节器的硬件电路。通过实验证明,基于DSP设计的数字式励磁调节器具有良好的励磁调节功能,能够对变流机组进行有效的励磁调节,具有较高的可靠性和稳定性。     

电磁式相复励自励系统的分析与研究

以基于IGBT分流电路的电磁式相复励装置励磁系统的某船舶电站为平台,对该种相复励自励装置的原理进行分析,并对装置中各部件与发电机输出电压之间的关系进行分析与研究。指出了系统分流电阻、相复励特性曲线与系统稳定性之间的关系。本文的结论可以直接应用到实际的电磁式相复励自励系统的调试中。     

船用中小型同步发电机励磁调节方式

通过对按3种原理设计的同步发电机自励恒压装置的讨论, 结合实际对同步发电机自励恒压电路进行剖析,增强船电技术人员在调试、维修船用中小型同步发电机励磁调节电路方面解决问题的能力.     

基于Maxwell对直流断路器吹弧装置的研究设计

基于Maxwell仿真分析软件以及电磁场理论,分析设计了直流断路器两种吹弧装置—永磁体励磁吹弧装置和线圈励磁吹弧装置,通过Maxwell对两种形式吹弧装置的磁场分布进行仿真分析,并通过试验比较两种吹弧装置的吹弧效果。研究结果表明,线圈励磁吹弧装置的吹弧效果优于永磁体励磁吹弧装置,且线圈励磁吹弧装置的吹弧磁场具有无极性的特点。     

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。