共查询到20条相似文献,搜索用时 15 毫秒
1.
海王星海底长期观测系统的技术分析 总被引:3,自引:0,他引:3
美国和加拿大为建立全球最大海洋观测网而联合开展的海王星计划被誉为人类的水下“哈勃”。文中首先介绍了海王星计划的由来与背景,然后分析了其基础架构及实现的关键技术,并对我国海底观测技术的发展提出了建议。 相似文献
2.
Power systems for undersea observatories combine ideas from terrestrial power systems and switching power supplies with experience from undersea cable systems. Basic system tradeoffs for various design decisions are explored in this paper. First, design questions including whether the power delivery should be alternating or direct current and a parallel or series network are examined. This introduces the question of maximum power delivery capability, which is explored in depth. A separate issue, the negative incremental resistance presented to the delivery system by the use of constant-voltage converters, is examined, and the resulting dynamics explored by simulation 相似文献
3.
能耗是制约海洋设备在水下工作时长的关键因素。为进一步降低海洋动态观测设备嵌入式系统的动态功耗, 本文针对前人提出的用于预测空闲时间的指数平滑算法所存在的权重系数基于凑数法确定、算法难以适应大波动等问题, 设计了一种新的权重系数, 并构建了一种自适应的低功耗管理预测模型。当模型检测到预测的空闲时间超过工作和休眠状态切换的时间阈值后, 中央处理器关停系统的部分外设, 使系统进入低功耗休眠状态。仿真和单片机实验均表明,本文提出的低功耗管理预测模型能够有效地提高对处理器工作的空闲时间预测的准确性, 且面对突发状况具有良好的自适应性, 可显著降低嵌入式系统的功耗, 有效延长设备的工作时间。 相似文献
4.
5.
A critical and potentially difficult problem for ocean-bottom observatories is the electrical power sub-system. While huge effort and expense has gone into development of land power grids and ocean communication cable power, the characteristics of ocean-bottom observatories require different strategies. Ocean-bottom observatories terminate on the ocean floor where large variable loads are installed, whereas commercial ocean-bottom cables terminate on land and normally have relatively fixed loads. Design considerations such as whether to use a constant current or constant voltage source, choice of voltage and current levels and cable capacitance and impedance are considered. Ocean-bottom observatory science requirements in the future will demand multiple loads along the cable, cable branches, fault protection and redundancy. The realities of high cable capacitance and the negative dynamic impedance of switching power supplies require that rapid load changes either be anticipated or prevented. Without proper control, rapid changes in load can result in instability and collapse of the power system. The strategy suggested in this paper requires that each load point (or junction box where science experiments will be attached to the system) be "smart" enough to keep load variations within tolerance bounds 相似文献
6.
国际海洋观测技术发展趋势与中国深海台站建设实践 总被引:4,自引:0,他引:4
20世纪80年代以来,海洋观测呈现"多元化、立体化、实时化"的发展趋势,地区和国家的海洋观测系统在关键海域发挥着重要作用。随着技术的发展和理念的创新,区域海洋观测系统被广泛应用并得到不断完善。国际海洋观测台站如英国爱尔兰海区域、美国卡罗来纳州海区和加拿大维多利亚海底实验观测网的多元化观测系统(VENUS)都是值得借鉴的例子,他们把多元化、立体化的实时测量数据与海洋物理、生态和生物化学模式紧密结合起来,实现了海洋环境的可预报性。同时,美国、英德法等国和日本实施的一系列海底观测系统,使海洋观测更加完备化。在这种国际大背景下,我国积极推进的海洋观测研究网络工程中的第一个深海台站——西沙海洋观测研究站在2008年已经建设完成并投入运行,该台站实现了长时效的多参数海洋环境实时监控。西沙观测系统主要包括自动气象站、岛屿外缘坐底式海底和海底边界层观测子系统、生物捕获器、西沙上层海洋环境观测子系统和海洋光学监测子系统等。由于海洋环境结构复杂、工作环境恶劣以及资源缺乏等因素的影响,海洋观测一直是高风险的工作。最后希望通过比较国内外观测系统,中国海洋观测事业能够学习国外先进的思路和技术,自身取得更大进步。 相似文献
7.
8.
利用雷雨、大风等灾害天气资料和电力事故历史数据资料,分析了电力事故发生的时空分布特征及其与雷雨、大风、日平均气温等天气要素之间的关系。进而利用事件概率回归(regression estimation of event probability,REEP)和Logistic回归分析方法,得到了日照市电力事故发生概率与雷雨、大风和日平均气温之间关系的预警模型。研究结果表明:1)雷雨、大风是造成日照市电力事故的重要气象因素。2)雷雨、大风和高温等灾害天气对电力事故的发生虽都有促成作用,但影响能力存在较大差距。3)两种回归分析模型对因子和变量之间关系均有较好的拟合效果,相较而言,REEP模型更为直观,Logistic回归分析方法更为客观,适用性更强。4)回归分析结果建立在客观资料基础上,回归模型具有准确性、实用性,可为电力事故预警发布系统提供理论和技术支持。 相似文献
9.
《Ocean Engineering》2004,31(11-12):1407-1421
The paper presents an optimization study for the mechanical and electrical equipment of an oscillating-water-column (OWC) wave power plant of fixed shoreline or nearshore type, equipped with an air turbine. The plant’s structure geometry is assumed to be given and the corresponding hydrodynamic coefficients are known as functions of wave frequency. A stochastic model is adopted for the energy conversion process from wave to air turbine, it being assumed that the system is linear. The optimization concerns the turbine size, represented by its rotor diameter D. Two alternative criteria are used: (i) maximization of the produced electrical energy, (ii) maximization of the annual profit. An example calculation is presented, based on the hydrodynamic coefficients of the OWC on the island of Pico, Azores, and on the aerodynamic performance curves of its Wells turbine. The influence of the following parameters upon optimized turbine size and rated power output is analyzed: wave climate, capital costs of mechanical and electrical equipment, operation and maintenance costs, discount rate, equipment lifetime and price of electrical energy supplied to the grid. 相似文献
10.
Logistical supply is costly for the deepwater oil and gas exploitation, thereby it is necessary to develop a novel power supply solution to improve the offshore structure’s self-holding capacity. The two-body point absorbers, as a renewable energy device, have achieved a rapid development. Heave plate is used to constrain the truss’s motion in the two-body point absorber, and the floater moves along the truss up and down. This two-body point absorber can be considered to be an essentially mass-spring-damper system. And it is well known that the heave plates have been widely used in the Spar platform to suppress the heave motions. So if the two-body point absorber can be modified to combine with offshore floating structures, this system can not only offer electric power to support operations or daily lives for the platform, but also control the large motions in the vertical plane. Following this concept, a novel tuned heave plate (THP) system is proposed for the conventional semi-submersible platform. In order to investigate the dynamic performances of the single THP, two experiments are conducted in this paper. First, the hydrodynamic coefficients of the heave plates are studied, and then the THP experiments are carried out to analyze its dynamic performance. It can be concluded that this THP is feasible and achieves the design objective. 相似文献
11.
Youngcheul Kwon 《Marine Georesources & Geotechnology》2016,34(3):199-209
A hybrid simulation system, HyCoS, was developed involving the control, measurement, and analysis process in order to realize the basic algorithm of hybrid consolidation simulation. The system was fully automated by the development of the program HyCoS. Furthermore, a computer program, CONPERM, was also developed to obtain soil constitutive relationships in compression and hydraulic conductivity from inputting the data from the HyCoS simulation. Two laboratory simulations were conducted in order to verify the system involving the basic algorithm of the system and two major components, the software and hardware operation. The objectives of this process are divided into two major aspects. The first was to confirm whether the experimental equipment, such as the consolidometer and control and data acquisition device, maintained a stable operation status during the whole period of the consolidation test. In addition, verification was also carried out to determine whether the target control can actually be maintained on the specimen. The second objective was to confirm the reliability of the data obtained from the system HyCoS. 相似文献
12.
对潜水员运载器的用途、总体布置进行了介绍 ,着重对推进电源、电力推进传动型式、推进系统主电路开关元件和电力推进控制电路进行了选择和确定 ,并通过船模阻力试验 ,对推进功率进行了验证。 相似文献
13.
14.
研究了激发态质子转移(ESPT)分子2-(2'-羟基苯基)苯并噻唑(HBT)在不同极性溶剂中的光开关行为,探讨了溶剂极性对HBT分子光开光效应的影响.揭示了光开关脉冲信号的形成原因,建立了基于光诱导HBT分子激发态非线性折射效应的皮秒全光开关的理论模型.根据对时间响应函数的理论计算和实验结果分析,确定了光开关脉冲信号下降前沿和上升后沿的形成机理以及影响因素,并提出了增强光开关信号下降前沿的关断深度,提升上升后沿的恢复速度的有效途径和方法.本文工作为制成皮秒量级关断,微秒甚至纳秒量级重新打开的快速全光开关器 相似文献
15.
16.
基于滨海核电站海上γ辐射剂量率的智能化自动监测系统是一种无人值守的辐射监测装备,可全天候、长时间、在线组网、连续自动测量水面和空气中的γ剂量率、获取水中γ能谱数据并进行核素识别和计算活度浓度,并实时地将监测数据通过无线通信链路和北斗短报文两种形式上传至地面数据服务中心。在非事故情况下,该系统是对核电厂监督性监测系统的重要补充和完善;在发生重大核安全事故或放射性物质泄漏的情况下,能够有效解决传统的派船巡测时方法不标准、数据不及时不连续、人员受照风险大、船只易受污染和行动代价高等问题;在恶劣的极端气象条件下,无人值守的自动监测系统能够为核电站提供实时有效的水体和空气中的γ剂量率、气象、海水温度等监测数据,有效地提升了核电站在极端气象条件下的监测能力,对滨海核电站整体的安全性和可靠性具有一定积极意义。 相似文献
17.
E. A. Kulikov I. V. Fine O. I. Yakovenko 《Izvestiya Atmospheric and Oceanic Physics》2014,50(5):498-507
The March 11, 2011, megaquake caused a catastrophic tsunami recorded throughout the Pacific. This paper presents an analysis of the sea-level records obtained from deep-water tsunami meters (DART and NEPTUNE). To evaluate the effect of the sea-level oscillations’ decay, a statistical analysis of observations and numerical modeling of tsunami generation and propagation have been conducted. The main goal is to uncover physical mechanisms of the tsunami wave field formation and evolution at scales up to tens of thousands of kilometers in space and a few days in time. It is shown that the tsunami lifetime is related to the wave-energy diffusion and dissipation processes. The decay time of the variance of the tsunami-generated level oscillations is about 1 day. Multiple reflections and scattering by irregularities of the bottom topography make the field of the secondary tsunami waves stochastic and incoherent: the distribution of the wave energy in the ocean reaches a statistical equilibrium in accordance with the Rayleigh-Jeans law of equipartition of the wave energy per degree of freedom. After the tsunami front has passed, the secondary-wave energy density turns out to be inversely proportional to the water depth. 相似文献
18.
19.
《Oceanic Engineering, IEEE Journal of》2005,30(3):647-648
The objective of this paper is to theoretically demonstrate how the operational frequency affects the efficiency of a low-speed generator. Due to the varying nature of underwater currents, the voltage from a current power converter has to be rectified first and then digitally reconverted into a stable alternating current. When designing a direct drive generator for water current power conversion, the operational frequency is, thus, a free design parameter and not a fixed value determined by the grid. Finite element method was used to determine the efficiency and weight. A higher frequency means larger frequency-dependent losses, but also a lighter machine. Even at the highest frequency in this study, the frequency-dependent losses were not high enough to overcome the gain of a lighter machine. If a large generator diameter can be allowed, the water current power converter should be designed with as high operational frequency as possible. 相似文献
20.
多波束测量过程中,受到多种因素的影响,不可避免地存在各种误差,其中系统某个部件出现故障也不少见,如换能器、行波管、大功率微波开关或表层声速仪等器件功能不正常,引起多波束每 ping (一个发射接收周期) 数据中部分固定波束号的测深结果发生系统性偏移,以 2003 年东海调查 SeaBat900X 数据为例,其在垂直航向正投影平面上出现类似“W”字型的系统误差。本文基于该批次数据,系统分析了该类型系统偏差成因及外观表现,针对性提出基于等均值-方差拟合模型的改正方法,首先对异常区域和正常区域分别拟合地形趋势线,统计其均值和方差;然后以正常区域为基准,对异常区域内数据进行压缩和移动;最后通过面积差法,对数据中存在的折射残差进行消除,从而有效去除“W”型残差。文中实测数据验证了本文算法的有效性和可行性,对多波束其他类型的测深系统偏差处理具有一定的参考意义。 相似文献