在海底观测网DC/DC变换器输出信号特征信息不明显的情况下,该文提出一种根据变换器输出信号过渡过程信息判断变换器健康状态的方法.以正激变换器为实验电路,采集输出信号过渡过程的数据,通过离散小波辅助EM算法构建高斯混合模型,实现对DC/DC变换器软故障的预警;当预警出现时,通过输出信号的过渡过程数据,利用基于所建数据样本库训练的SVM分类器,判断变换器所属状态.仿真实验表明所提方法的有效性.

海底观测网电力系统供电海缆易发生绝缘故障,由于其在海底极端环境下运行,实现高精度的电缆故障定位,对于降低其维修成本至关重要.基于海底观测网电能监控系统实时采集的电气测量参数,本文提出了基于主成分分析(Principal Components Analysis,PCA)和长短期记忆(Long Short-Term Memory,LSTM)网络的供电海缆高阻故障定位方法,先使用PCA进行数据降维,再将处理后的数据输入LSTM网络进行训练,捕获多源数据的时间特征,挖掘电力系统故障特征与电气参数之间的对应关系,实现海缆故障精确定位.通过在海底观测网原型系统上的实验证明,该方法经K折交叉验证方法(K-fold Cross Validation,K-CV)验证,准确率可达91％左右,故障定位误差约为0.4 km.

As the core of electronic system, the switched-mode power supply (SMPS) will lead to serious accidents and catastrophes if it suddenly fails. According to the related research, the monitoring of ripple can acquire the health degree of SMPS indirectly. To realize low-cost, high-precision, and automatic ripple measurement, this paper proposes a new ripple voltage (peak-to-peak value) measuring scheme, utilizing a DAC and two high-speed comparators. Within this scheme, the DC component of SMPS output is blocked by a high-pass filter (HPF). Then, the filtered signal and the reference voltage from a DAC together compose the input of a high-speed comparator. Finally, output pulses of the comparator are captured by a microcontroller unit (MCU), which readjusts the output of the DAC by calculation, and this process is repeated until the DAC output is exactly equal to the peak (or valley) value of ripple. Moreover, in order to accelerate the measurement process, a peak estimation method is specially designed to calculate the output ripple peak (or valley) value of buck topology through merely two measurements. Then the binary search method is utilized to obtain a more exact value on the basis of estimative results. Additionally, an analysis of the measurement error of this ripple measurement system is executed, which shows that the theoretical error is less than 0.5% where the ripple value is larger than 500 mV. Furthermore, appropriate components are selected, and a prototype is manufactured to verify the validity of the proposed theory.

The reliability of power packs is very important for the performance of electronic equipment and ensuring the reliability of power electronic circuits is especially vital for equipment security. An alteration in the converter component parameter can lead to the decline of the power supply quality. In order to effectively prevent failure and estimate the remaining useful life (RUL) of superbuck converters, a circuit failure prognostics framework is proposed in this paper. We employ the average value and ripple value of circuit output voltage as a feature set to calculate the Mahalanobis distance (MD) in order to reflect the health status of the circuit. Time varying MD sets form the circuit state time series. According to the working condition time series that have been obtained, we can predict the later situation with support vector regression (SVR). SVR has been improved by a modified grey wolf optimizer (MGWO) algorithm before estimating the RUL. This is the first attempt to apply the modified version of the grey wolf optimizer (GWO) to circuit prognostics and system health management (PHM). Subsequently, benchmark functions have been used to validate the performance of the MGWO. Finally, the simulation results of comparative experiments demonstrate that MGWO-SVR can predict the RUL of circuits with smaller error and higher prediction precision.

Almost all materials are affected by an unavoidable phenomenon in seawater condition, called biofouling. Biofouling has long been considered as a limiting factor in ocean observations. Many potential methods to fight against this problem have been proposed but none of them seems to be universally applicable. The effect is affected by environmental factors and the characteristics of the object being protected. This paper presents bio-fouling formation mechanism and the influences of various environment factors. Emphasis is put on the introductions of various anti-biofouling methods, including the characteristics and limitations. These methods usually can be summarized as two kinds:active and passive ways. At last, according to the characteristics of various anti-biofouling methods and the protected objects, this paper recommends anti-biofouling strategies for some parts of the typical ocean observation equipments, which provides the guarantee for the long-term ocean observing.

利用海流发电装置原位地捕获能量将成为实现海底观测仪器长期供电的一种新方式.对海流发电装置翼型前缘及后缘进行结构改进,并利用FLUENT软件和k-ωSST两方程湍流模型对翼型绕流问题进行求解,结果表明前缘半径适当增大,最大升阻比增大,失速攻角将变大;而采用对称增加后缘厚度的方法,升力系数随厚度增大略有提升,但阻力系数亦同时增大.

Scientific cabled seafloor observatory networks (SCSONs) will be a powerful tool for oceanography research.This paper reviews the state-of-the-art of cabled SCSONs' five critical technologies,i.e.,undersea high-voltage direct-current transmission and distribution,undersea high-voltage high-frequency de-de conversion,undersea remote power monitoring and control,undersea long haul information transmission,and in-situ scientific instrument laboratories.The progress of SCSONs around the world is summarized,and the future perspective of SCSONs is also discussed.

为了持续提供充裕的电能给大量原位科学仪器,设计了东海缆系海底观测试验网电力系统,建立了其核心电力元件的数学模型,并分析了其静态和暂态稳定性.采用小扰动法分析了系统静态稳定性,获得了系统静态稳定判据,证明了切负荷可提高系统静态稳定性.采用相平面法和Saber仿真分析了系统暂态稳定性,发现改变核心电力元件的特性或参数,如减小海底负荷,增大海缆等效电阻,减小海缆等效电容或增加岸基远供设备输出电压的调节时间等方法,均可提高系统暂态稳定性.研制的试验网电力系统长期运行稳定可靠,证明了系统设计合理可行.更多还原

Cabled seafloor observatory networks(CSONs)can provide a large amount of undersea scientific instruments with sustained and abundant power.According to the principles of reliability and economy,the paper illustrates why the power system of CSONs is suitable to adopt the negative monopole DC transmission scheme with the seawater as the current returning path by parallel connecting undersea loads,and employing the cascaded high-frequency DC-DC conversion system,and then the CSONs’ physical structure is established based on the analysis. According to the CSON’s characteristics, several typical undersea power system topologies are summarized.With the average power feeding reliability of the undersea stations as the reliability index,the reliability indexes of these typical topologies are calculated and compared.This method can provide a basis for the CSONs’ topology planning.Furthermore,the operation mode of the undersea power system is designed to enhance the CSONs’ fault-tolerance capability.The study can be a reference for the future construction of large-scale national CSONs.

为提高缆系海底观测网的用能效率和运行可靠性,根据其物理架构特点设计了远程电能监控系统的总体结构,根据功能将该系统划分为数据采集、负载管理和网络分析三个子系统,说明了子系统的主要功能和相互关系.并研究了该系统的时间同步方案、负载供电优化策略和网络分析算法.通过理论分析,获得了分支单元节点电压向量的加权最小二乘状态估计公式,并基于电切换型分支单元的可控性,提出了海缆接地故障定位的新方法.研究内容可为未来国家海底观测网的设计和运行提供参考.

An undersea analyzing system for long-term measurement of seawater anions,concentration down to 4000-meter depth was designed and implimented.It can detect the anions such as F;,Cl;,Br;,NO;,SO;,PO;,etc.by the method of ion chromatography.A prototype was made based on the design of sealed pressure housing and pressure balancing housing and it was tested by sea trail.The calibration device addresses the issue of deviation during longterm working,and the dilution parts can solve the too concentrated problem of the anions to be detected.In sea trail,the system was deployed at seafloor and connected to the ocean observatory at the depth of about 900 meters.The trail lasted for 6 months and results demonstrated the system’s stability during long-term working and precision of seawater anions monitoring.

The science community has proposed to establish large-scale long-term cabled seafloor observatories in the Chinese marginal seas. In this preparation phase, a small-scale experimental cabled seafloor observatory in East China Sea is under construction. The overall system structure of the experimental observatory is introduced. The critical power components of the undersea power system, which are the power feeding equipment, the submarine communications cable, and the undersea power converter, is designed and modeled. The backbone power delivery system is analyzed based on these models. The laboratory test proves the feasibility and reliability of the design. Finally, a power management system is designed to monitor and control the overall electric energy of the undersea power system.

Fault ground resistor value should be measured accurately to monitor this fault in underwater equipments.Traditional method is measuring the voltage on the two ends of the sampling resistor with invariable value. Due to the extremely wide range of the resistor value,this measure can’t assure the accuracy.The paper proposes a new method of using switchable sampling resistors and processing data by weighted fusion algorithm.The test result proved that this new method improves the measure accuracy.

A prototype system for cabled seafloor observatory networks was designed to continuously monitor the deep ocean with real-time and in-situ experiments. The system adopts up to 10 kV direct current power transmission and 100 Mb/s fiber-optic communication techniques. It consists of an undersea science node, an electro-optic submarine cable and a shore control station. The science node consists of an in-situ chemical analyzer, a dynamic environment monitor and a node junction box. The users could download science data from the data management subsystem in real-time, remotely monitor the instrument status with the power monitoring subsystem and carry out seafloor in-situ experiments. After tested under high pressure and in the laboratory tank for several times, the system has been operated stably in the East China Sea shallow water trial and the US Monterey Accelerated Research System (MARS) deep-sea experiment, and has obtained a large amount of high-resolution science data. Experiment results prove that the system design is reasonable and feasible, and the cabled seafloor observatory networks show advantages over traditional ocean observation approaches.

Cabled ocean observatories could provide a large amount of undersea instruments with sustained considerable electrical power and broadband two-way communications bandwidth for decades. Then scientists could remotely perform interactive and adaptive experiments and analyze long time-series high-resolution data from interesting events. A multidisciplinary undersea science node for deep-sea chemical-physical-biological research is developed with emphasis on reliability, flexibility, and fault resilience. The science node, rated up to 4000 m, is consisting of an in-situ seawater parameter analyzing system, an in-situ dynamic environment monitoring system, an in-situ biodiversity observing system, and an underwater junction system. After high pressure experiments and shallow seawater trials, the science node has been tested on Monterey Accelerated Research System (MARS) managed by Monterey Bay Aquarium Research Institute (MBARI).

The land Grid transmits continuous electrical power to sub-sea cabled observatory networks through optic-electric hybrid cables and underwater junction boxes.A power monitoring and control system(PMACS) is designed for the underwater junction boxes,in order to increase the reliability and efficiency of the undersea power system.By measuring the environment parameters of the pressure vessels,the working conditions of dc-dc converters,and the power consumptions of internal and external loads,the PMACS diagnoses system faults and takes protective measures,manages all loads according to their priorities,and can be controlled and maintained by the remote console located at the shore station.The PMACS is tested on a junction box prototype rated-2kV/2kW and proved to be stable and reliable and suitable to be used in sub-sea long-term observatory networks.

Monterey Accelerated Research System（MARS） is a main test bed for the deep-sea observatory instruments in the world.On April 14 th,2011,a China node,which consists of a junction box,a chemical environment system and a dynamical environment system,was installed on MARS successfully by R/V Western Flyer,R/V Point Lobos and ROV Ventana for long-term test at the seafloor of Monterey Bay.China became the third country who tested her deep-sea observatory instruments on MARS on a large scale.Up to date,China node works well on MARS.The instruments of China node are sending data back from the seafloor of Monterey Bay.China node test on MARS shows that Chinese observatory technologies have had great progresses in the recent four years,which can be applied to the construction of the deep-sea observatory in China.Real-time data from China node will benefit marine research and show great advantages of deep-sea observatory.

According to the characteristic of the two-electrode conductivity cell, a conductivity measurement system of high precision was designed based on the signal processing technology. The paper described the principal of square wave excitation for conductivity measurement, the system hardware design and software working process. Experiment results show that the system has the feature of high precision, wide scale range and fast measurement, and it could be applied in laboratory instruments and industry devices.