基于Matlab对直流脉冲发电机系统的建模仿真

目前,船舶应用领域的直流脉冲发电机系统设计一般采用相关工程计算和经验确定设备,再通过设备联调来确定系统相关参数,存在设计周期相对较长,控制方式不一定最优等问题.本文借助Matlab/Simulink工具箱,在分析直流发电机数学模型的基础上,通过等效电路方法建立了电枢电流模块、机械回路模块等独立模块,搭建了直流脉冲发电机系统仿真模型,仿真试验验证了系统模型的正确性.该系统模型可为直流脉冲发电机系统设计、控制方法的选择、相关参数的修改等提供依据.     

船用发电机数字励磁系统的精确建模研究

为提高船用发电机励磁系统的仿真精度,建立模型励磁控制参数与实际控制参数间的对应关系,以某船数字励磁系统实例,探讨了根据相关设备参数和控制装置的实际算法对船用发电机数字励磁系统进行精确建模的过程和可行性,最终使用Matlab/Simulink搭建了对应该船数字励磁系统的精确仿真模型,利用试验结果验证了模型的正确性.     

十二相同步发电机的电路模型及仿真

在十二相同步发电机基本数学模型的基础上,根据整流绕组各参数间的等值关系,推导出其磁链方程及等效电路,并基于MATLAB/simulink的仿真环境建立了该型发电机的仿真模型。该模型考虑了整流绕组之间互感不相等的情况,使其更符合实际。利用此模型可以更方便地研究十二相同步整流发电机系统的各项性能。最后通过实机试验检验了模型的正确性。     

某型充电发电机可靠性试验系统设计与仿真

十二相整流充电发电机常应用于需要高品质直流电源的场所,充电发电机的可靠性试验可以为该型电机的运行状况、维护保养及确定修理周期提供科学依据。文章结合可靠性试验的基本理论,分析了充电发电机恒定应力加速可靠性试验方案,设计了发电机输出作为直流电动机电源的能量反馈试验拖动系统,并进行了基于PSCAD/EMTDC的可靠性试验系统的动态性能仿真分析。仿真结果表明能量反馈可靠性试验系统响应快、稳定性良好。     

基于积分分离PID调节方法的直流发电机控制系统优化设计

现有的消磁用直流脉冲发电机控制系统采用双反馈控制方式,在此基础上对控制系统的模型进行了PID调节仿真,并针对消磁工作电流波形的特点提出了采用积分分离PID调节方法。仿真结果表明该调节方法对电流波形的控制效果最优。     

海上平台新能源单元主动式虚拟直流电机技术

针对海上平台多种新能源构成的电力电子化直流微网系统具有低惯量、弱阻尼特性，以及海上新能源强的间歇性所引起的微网系统稳定性问题，在风力发电单元、光伏发电单元的接口直流变换器中，采用主动式虚拟直流发电机技术，即接口变换器的控制系统中加入直流发电机机械方程和电磁特性方程，使其具有直流发电机惯量特性与阻尼特性，减缓在风光发电单元出力突变时对母线电压冲击，以提高直流微网系统惯性。建立虚拟直流发电机控制小信号模型，分析其中惯量系数和阻尼系数对于系统稳定性影响机理，利用小信号线性模型根轨迹获得参数的优化设计准则。仿真结果表明，采用所提出的虚拟直流发电机控制方法极大弱化风光间歇性对于母线电压冲击的影响，同时提高了弱电网特性下微网稳定性，验证了该方法理论正确性与可行性，在新能源独立供电弱网条件下具有广泛的应用前景。     

综合电力系统直流侧突加负载的电压影响

研究在综合电力系统中压直流侧突加负载时系统侧瞬时电压变化的计算方法。在十二相同步发电机的降阶等效模型基础上,基于其等效三相发电机整流系统直流侧突加阻性负载瞬时电压计算式,给出基于综合电力系统多台十二相同步发电机组并联运行下的瞬态电压降估算方法,并用1组算例数据和仿真模型,验证单机压降计算方法的有效性。     

十二相不控整流发电机并联运行的建模与仿真

多相整流发电机因其直流供电品质高、可靠性高,在船舶电力推进中得到了越来越多的应用,整流发电机的并联运行对于提高船舶电力系统的容量和安全性具有重要意义。推导了十二相同步发电机的数学模型,在MATLAB/Simulink中建立了两台带不控整流的十二相同步发电机并联运行的仿真模型。探讨了两台并联运行发电机间功率分配的控制策略,设计了电压—电流下垂特性曲线和曲线截距的自动补偿,并将其应用到励磁控制系统中。通过仿真实验,验证了该控制系统的有效性。     

基于双PWM变换器的轴带发电系统控制策略研究

本文提出了一种由双PWM变换器构成的新型轴带发电系统控制策略,其整流侧将轴带发电机发出的电压、频率变化的交流电变换为直流电;逆变侧采用虚拟同步发电机控制策略,使逆变器具有与柴油发电机相似的输出下垂特性和电气、机械特性,保证该轴带发电系统能与常规的柴油发电机组长期稳定并联运行。在MATLAB/Simulink环境下搭建了该新型轴带发电系统的仿真模型,对其与柴油发电机组的并联运行进行了模拟,对模型中转动惯量对系统的影响进行了分析,验证了该控制策略的可行性。     

新型船用发电机功率平衡电路研究与应用

本文针对并联发电机系统的功率平衡控制要求,提出了一种基于电压源等效模型的功率平衡新方案,并设计了功率平衡电路,建立了并联运行机组的MATLAB仿真模型.仿真计算与实际运行结果表明,该功率平衡新方案能有效调节各发电机的功率输出,有利于船舶电站的安全和可靠运行.     

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;     

33rd International Conference on Ocean,Offshore and Arctic Engineering （OMAE2014）

正San Francisco,California,June 8-13,2014.OMAE 2014 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;·to exchange ideas and experiences whilst promoting technological progress and its application in industry·to promote international cooperation in ocean,offshore and arctic engineering.In line with the tradition of excellence of previous OMAE conferences,more than 900 technical papers are planned for presentation.Outreach for Engineers Specialty Forum This Specialty Forum is designed for students and professionals who may not be familiar with the Ocean and Offshore industry,as well as those who have just recently specialized in this field.     

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。     

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.     

The 11th International Conference on Hydrodynamics (ICHD 2014)

正19–24 October 2014 SingaporeCONFERENCE THEMES The overall aim of the ICHD Conference is to provide a forum for participants from around the world to review,discuss and present the latest developments in the broad discipline of hydrodynamics and fluid mechanics.The first International Conference on Hydrodynamics(ICHD)was initiated in 1994 in Wuxi,China.Since then,9 more ICHD conferences were held subsequently in Hong Kong,Seoul,Yokohama,Tainan,Perth,Ischia,Nantes,Shanghai and St Petersburg.Evidently the ICHD conference has become an important event among academics,researchers,engineers and operators,working in the fields closely related to the science and technology of hydrodynamics.The 11th ICHD will be held in Singapore in 2014.     

第十二届深水操作会议和展览会(英文)

正November 4-6,2014Moody Gardens HotelConvention Center/Galveston,TX The Deepwater Operations Conference and Exhibition is celebrating its 12th anniversary this year.This growing event will continue the tradition of excellence in addressing operational challenges involved in developing deepwater resources.We will return to the Moody Gardens Hotel and Convention Center on November 5-7,2014 in Galveston,Texas.     

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）.     

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.