Study on 10 kVDC Powered Junction Box for A Cabled Ocean Observatory System

A cabled ocean observatory system that can provide abundant power and broad bandwidth communication for undersea instruments is developed. A 10 kV direct current （kVDC） with up to 10 kW power, along with l Gigabit/sec Ethemet communication, can be transmitted from the shore to the seafloor through an umbilical armored cable. A subsea junction box is fixed at a cable terminal, enabling the extension of up to nine connections. The box consists of three main pressure vessels that perform power conversion, power distribution, and real-time communication functions. A method of stacking modules is used to design the power conversion system in order to reduce the 10 kV voltage to levels that can power the attached instruments. A power distribution system and an Ethemet communication system are introduced to control the power supply and transmit data or commands between the terminals and the shore station, respectively. Specific validations of all sections were qualified in a laboratory environment prior to the sea trial. The ocean observatory system was then deployed at the coast of the East China Sea along with three in situ instruments for a 14-day test. The results show that this high voltage-powered observatory system is effective for subsea long-term and real-time observations.

Design and manufacture of a 100 kA coaxial pulsed power cable for plasma generator and PPS in ETC guns

Based on our previous pulsed current and internal overvoltage test data and the experience of common commercial high power cables,a 100 kA coaxial pulsed power cable is designed and manufactured to adapt the coaxial electric energy breech transmission between the plasma generator and the pulsed power supply(PPS) in electrothermal-chemical(ETC) guns.The index parameters are analyzed and determined.Semi-conductor layers and a shield stiffener are introduced to prevent the deformation and burst of the pulsed power cable structurally.The semi-conductor layer can eliminate the air gap and balance the electric field in the cable.The shield stiffener can multiply the mechanical strength to restrain the strong electrodynamic force produced by the core dislocation of the outer conductor.The multi-coupling of electromagnetic field,stress field and thermal field analysis are established to assist in aided design of electrical strength,mechanical strength and temperature rise characteristics.Both a DC voltage withstand test and pulsed discharge tests are introduced to verify and inspect the performance and dynamic response of the pulsed power cable.The 25 kV/5 min DC voltage withstand test result shows that the sample leakage current is nearly 3 μA and no abnormal phenomena of the pulsed power cable sample occurred.The pulsed discharge tests show that the sample can sustain the 100 kA peak current.Furthermore,this 100 kA coaxial pulsed power cable can satisfy the ETC test requirements.

Analysis of the Design and Application of a Novel CT Secondary Cable Line Calibrator

With the rapid development of electrical power systems,ensuring the accuracy and reliability of power transmis-sion has become particularly crucial.The secondary cable line calibrator for current transformers(CT)plays an essential role in calibrating electrical power systems.It is not only related to the safe operation of the system but also directly im-pacts the accuracy of energy metering.This study aims to design and analyze an efficient CT secondary cable line calibra-tor to explore its application effects in the power system.By thoroughly analyzing the characteristics of CT secondary ca-ble lines and the design requirements of the calibrator,this paper proposes an innovative design scheme for the calibrator.This device demonstrates significant effects in enhancing the accuracy and stability of power system calibration,providing robust technical support for the optimization and upgrade of the power system.This research not only offers a theoretical basis and practical guidance for the design and application of CT secondary cable line calibrators but also contributes new ideas and methods for the precise calibration and efficient management of the power system.

Scheme of long distance power supply for electrified railway traction network based on traction cable

Purpose–The traction cable is paralleled with the existing traction network of electrified railway through transverse connecting line to form the scheme of long distance power supply for the traction network.This paper aims to study the scheme composition and power supply distance(PSD)of the scheme.Design/methodology/approach–Based on the structure of parallel traction network(referred to as“cable traction network(CTN)”),the power supply modes(PSMs)are divided into cableþdirect PSM and cableþautotransformer(AT)PSM(including Japanese mode,French mode and new mode).Taking cableþJapanese AT PSM as an example,the scheme of long distance power supply for CTN under the PSMs of co-phase and out-of-phase power supply are designed.On the basis of establishing the equivalent circuit model and the chain circuit model of CTN,taking the train working voltage as the constraint condition,and based on the power flow calculation of multiple train loads,the calculation formula and process for determining the PSD of CTN are given.The impedance and PSD of CTN under the cableþAT PSM are simulated and analyzed,and a certain line is taken as an example to compare the scheme design.Findings–Results show that the equivalent impedance of CTN under the cableþAT PSM is smaller,and the PSD is about 2.5 times of that under the AT PSM,which can effectively increase the PSD and the flexibility of external power supply location.Originality/value–The research content can effectively improve the PSD of traction power supply system and has important reference value for the engineering application of the scheme.

Analysis of DC Power Transmission Using High T_c Superconducting Cables

A conceptual superconducting DC cable model is designed and its magnetic fields distribution is analyzed with Ansoft/Maxwell soft. A DC Power transmission system is also studied by using the Matlab/Simulink. With the DC Line and AC Ground Fault, the system losses analysis is introduced.The analysis results mainly include the magnetic fields distribution of the HTS cable model with Ansoft/Maxwell, the system loss, the DC Line and AC Ground Fault with Matlab/Simulation.

A 4m 2kA HTS Power Cable System

A high temperature superconductor （HTS） cable system of both a length of 4 metre and a normal current of 2 KA with terminations and a cooling system has been built up and tested. The cable conductor was made of Bi-2223 tape. A space maintained vacuum between two corrugated stainless steel tubes functions as the cryostat surrounding the superconductor. A series of tests were carried out to verify the functions of the system. The important data obtained can be used to make longer HTS cable systems.

Online Loss Parameters Diagnosis Device Development of Power Cable Insulation

In southern China, power cable lines often running in water, and the state of XLPE insulation is difficult to detection effectively. This paper studied loss parameters online diagnosis technology of power cable insulation. An online loss parameters diagnosis device was development, which consists of current comparator, voltage controlled current source (VCCS), standard capacitor, GPRS wireless transmission system, control system and the data processing unit. 108 cables were detected using this device, and it was found out that one cable appeared to middle aging and eight cables appeared to slight aging. The butterfly water trees were observed in middle aging cable, which prove the effectiveness of online testing in the loss current measurement.

HTS Power Cable Developed

With the support of the National Center for R&D on Superconductivity, a 6m high T_c superconducting (HTS) power cable has cartied a current of 1473 A successfully at the Institute of Electrical Engineering (IEE), CAS. In 1998, a one-meter-long, 1000A HTS power cable prototype was developed successfully by

Power over Cable:整合数据传输与供电,单一缆线解决工业视觉应用的需求

所有的工业机器视觉设备都需要依赖图像数据传输与电源供应,而且大多数的工业相机都需要使用两条缆线,一条用于传输数据,另一条则是电源线,这意味着使用者必须多花一倍安装与维护缆线的成本,同时缆线故障的机率也增加一倍。随着工业机器视觉市场从模拟跨入数字相机后,如何通过"Power over Cable"供电型接口简化安装、节省空间以及降低成本,成为工业机器视觉应用中最新的话题。

Aging Characteristics of XLPE Insulation of 110 kV Cables in the Initial Stage of Operation

The aging characteristics of the XLPE insulation of 110 kV power cables in the initial stage of operation are studied in this paper.The XLPE insulation from cables with different running time was tested by using electrical and physicochemical methods,from which the degradation state of XLPE under multiple stresses during operation was derived.The broadband dielectric spectrum test taken from 10–1 to 10^(6) Hz showed that the dielectric constant and dielectric loss of the XLPE insulation first decrease and then increase with the increase of cable running time,which show obvious variation until 10 years of operation.The AC breakdown strengths of the XLPE insulation of operated cables with the service year no longer than 10 years were higher than that of new cables.The mechanical properties of the XLPE insulation showed no dependence with the cable running time.The crystallinity and perfection of the crystallization area were found to be enhanced during operation and the polar functional groups inside the XLPE insulation were found to be determined not only by the cross-linking by-products but also by the oxidation process during cable operation.The experimental results in this paper are important for improving the operation reliability and reducing the maintenance costs of the cables.

Live-Grid Operation and Maintenance of the 35 kV/121 MVA Superconducting Cable System

A 33.5 m, 35 kV/121 MVA, three-phase, warm dielectric HTS power cable system was successfully installed and activated in China Southern Power Grid at the Puji substation in Kunming on April 19th of 2004, supplying electricity to four industrial customers （including two metallurgical refineries） and a residential population of about 100000. In this paper, we give an update on the operation and maintenance status of the system and comments on reliability issues. We conclude that the superconducting cable system is currently quite robust and feasible for particular utility applications, and it will be improved by advancement in cryogenic equipment and system technology.

Performance Evaluation for Medium Voltage MIMO-OFDM Power Line Communication System

Power line communication(PLC)provides intelligent electrical functions such as power quality measurement,fault surveys,and remote control of electrical network.Most of research works have been done in low voltage(LV)scenario due to the fast development of in-home PLC.The aim of this paper is to evaluate the link-level performance of a medium voltage(MV)MIMO-OFDM communication system based on transmission link under underground power line channel.The MIMO channel is modeled as a modified multipath model in the presence of impulsive noise and background noise.We first perform a measurement on the practical MV MIMO channel parameters for a section of buried cable of 1 km long in Ganzhou city,Jiangxi province,China.Based on the measured channel,we design the frame structure based on an IEEE standard for broadband over power line networks[1]to support MV MIMO-OFDM transmission.According to designed frame structure,we design an encoder and a decoder for a dual binary tail-biting turbo code and optimize some key decoder parameters for low bit error rate performance.Finally,the link-level performance for both spatial multiplexing and spatial diversity are evaluated.Numeral results show that MV MIMO-OFDM is a promising approach to provide both high data rate and link reliability for PLC.

Industrial frequency single-phase AC traction power supply system for urban rail transit and its key technologies

To avoid stray current and maintain the benefit of no phase-split in the DC traction power supply system, an AC traction power supply system was proposed for the urban public transport such as metro and light rail transit. The proposed system consists of a main substation （MSS） and cable traction network （CTN）. The MSS includes a single-phase main traction transformer and a negative-se- quence compensation device, while the CTN includes double-core cables, traction transformers, overhead catenary system, rails, etc. Several key techniques for the proposed system were put forward and discussed, which can be summarized as （1） the power supply principle, equivalent circuit and transmission ability of the CTN, the cable-catenary matching technique, and the selection of catenary voltage level; （2） the segmentation technology and status identification method for traction power supply network, distributed and centralized protection schemes, etc.; （3） a power supply scheme for single-line MSS and a power supply scheme of MSS shared by two or more lines. The proposed industrial frequency single-phase AC traction power supply system shows an excellent technical performance, good economy, and high reliability, hence provides a new alternative for metro and urban rail transit power supply systems.

基于Creo2.0 Cabling的三维自动布线技术研究

针对目前电力行业三维布线技术布线效率低的问题,综合分析了自动布线与手动布线的优缺点,提出了一种基于Creo2.0 Cabling模块的系统、高效、可行的三维自动布线设计方法。首先,为了最大限度地减少自动布线时重复绘制接线表的工作量,提出了绘制.dgm通用接线表的设计方法。其次,为实现三维布线时输入端的自动识别,提出了在连接器建模时添加并设置输入端坐标系的建模方法。同时利用Creo2.0的族表功能,将连接器系列尺寸导入族表,快速实现了不同连接器系列的标准模型库建立。最后,系统阐述了该方法应用的关键技术。该方法在某科研样机开发过程中的成功应用,有效验证了自动布线技术的显著优越性,对三维布线技术在电力行业的推广具有重要意义。

虑及互耦效应的线缆辐射EMI建模

并行布线结构的开关电源线缆是开关电源辐射电磁干扰EMI(electromagnetic interference)的重要干扰源。针对并行线缆间辐射场互耦效应机理不明晰使得辐射电磁干扰预测不准确的问题,提出1种虑及线缆间互耦效应开关电源线缆的辐射电磁干扰模型。通过对描述线缆互耦效应的互阻抗建模,得到描述开关电源线缆辐射特性的辐射EMI输入阻抗模型,进而得到虑及互耦效应开关电源线缆的辐射EMI模型;搭建辐射EMI测试实验平台进行测试。实验结果表明,所提虑及互耦效应的辐射电磁干扰模型能够更为准确地预测开关电源线缆的辐射电磁干扰。

Development and Construction of 345 kV Power-Optical Fiber Composite XLPE 2,500 mm2 with Prefabricated Joint

Due to the increasing demand of replacing large capacity overhead lines with underground cables in Korea, KEPCO （Korea Electric Power Corporation） and LS Cable （LS Cable ＆ System） have developed 345 kV optical fiber composite XLPE （cross-linked polyethylene） 2,500 mm2 cable system. This system has been installed in Cheongna district of Incheon city. KEPCO and LS Cable are also planning to build the cooling system in a tunnel in order to reduce the ambient temperature caused by currents. In this paper, the process of development, field installation, and final inspection test of the complete system will be described.

Converged Communication Technology and Application in Intelligent Dual-Interactive Power System

Acknowledgments Thanks for assistance and support, which is provided by State Grid Corporation of China and State Grid Communication Information ＆ Telecommunication Company, for the project in the process of research and development. Fibrlink Communications Co., Ltd will keep exerting itself to innovating, which aims for making more contribution of the smart grid on energy reduction and environment protection.

UWB HPM对雷达方舱内电子设备的影响仿真分析

针对高功率微波辐照下雷达方舱内电子设备的响应和毁伤效应等实际问题,通过建立雷达方舱和舱内电缆模型进行了辐照仿真分析。结果表明,高功率微波信号在进入方舱时,方舱起到一定的滤波作用,类似带通滤波器;雷达方舱和舱内设备的反射会影响方舱内场强分布和极化,造成方舱内电场分布不均匀,各向异性降低,但尚未达到混响室程度;通过仿真概略计算了方舱内信号分布和传输特性;方舱内电缆耦合信号电压基本在同一个数量级,超宽谱信号辐照影响主要以扰乱为主。针对上述影响,提出了相应加固措施,可为雷达在高功率微波武器攻击下进行后门防护加固提供理论支撑。

氢闸流管驱动三同轴电缆Blumlein线的kHz重频脉冲功率源

闪光X射线摄影技术在军事和民用等多个领域具有重要场景。针对重频直线感应加速器高重频的要求,提出了基于氢闸流管驱动三同轴电缆Blumlein线的脉冲功率源方案,设计和研制了一种三同轴电缆,研究了氢闸流管的导通特性,搭建了氢闸流管驱动三同轴电缆Blumlein线脉冲功率源的验证平台,开展了kHz重频脉冲功率源实验研究,以及kHz重频脉冲功率源驱动重频感应腔的实验研究,结果表明:基于氢闸流管驱动三同轴电缆Blumlein线脉冲功率源实现了波形品质优异的kHz重频方波脉冲输出。