检索结果-南通市图书馆

New two chamber transfer switch for 6500 A commutation current

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Global Energy Interconnection 2018年第3期1卷 344-351页

作者： Lutz-Rüdiger Jänicke Jörg Teichmann Shibani Bose Weidong Han Xiaoming Wang siemens ag siemens Ltd.China siemens High voltage Circuit Breaker Co. Ltd.

HVDC transfer switches are used in different locations in electrode lines of HVDC transmission systems for their reconfigurations. They have to carry and commutate currents to the overload currents of HVDC transmission systems, which increased to 6,400 A in the past years. Common designs of transfer switches use combinations of several switching units connected in series and parallel. This paper describes the design and development of a new DC commutation switch with two switching units only, but it is able to carry currents up to 10,000 A and has an actual tested commutation capability of 6,500 A.

关键词： HVDC Switch Passive resonance 6,500 A commutation current 10,000 A nominal current

同方期刊数据库

Overview of development, design, testing and application of compact gas-insulated DC systems up to ±550 kV

在线全文

学校读者我要写书评

暂无评论

Global Energy Interconnection 2019年第6期2卷 568-578页

作者： Maria Kosse Dejun Li Karsten Juhre Mark Kuschel siemens ag FreyeslebenstraBe 191058 ErlangenGermany siemens Ltd. 500 Da Lian RoadShanghai 200082P.R.China siemens ag Nonnendammallee 10413629 BerlinGermany

The development of high-voltage direct current gas-insulated switchgear assemblies(DC GIS)of rated voltages up to±550 kV has been *** GIS provide a compact technical solution with a high functional density,optimized for projects with limited space as in offshore HVDC converter platforms,onshore HVDC converter stations and transition stations between different transmission *** to now,no standards for testing of gas-insulated DC systems are available,although pre-standardization work is in progress within *** tests can be performed as required in AC GIS *** aspects of DC voltage stress,like the electric field distribution of insulators influenced by the accumulation of electrical charge carriers and the operation-related inhomogeneous temperature distribution,must be considered by additional electric and thermoelectric *** DC GIS,the experience of long-term performance is limited *** ageing is expected to be of lower importance,tests are *** contribution summarizes the physical and technical background to design and develop compact DC switchgear assemblies using gas-insulated *** explains the developed modules of the substation and gives an overview of the performed ***,it provides an insight in the on-going standardization activities and describes applications in converter and transition stations,showing its space-saving characteristics.

关键词： Direct current gas-insulated switchgear assemblies DC GIS Direct current gas-insulated transmission lines DC GIL Modular design Underground installation Containerized installation Offshore platform installation Transition station

Design Essentials and Experience with Modular Combined-Cycle Power Plants

在线全文

学校读者我要写书评

暂无评论

Design Essentials and Experience with Modular Combined-Cycle...

Testing methods for 1100 kV UHVDC transformer

CSPE-JSME-ASME International Conference on Power Engineering

作者： Lothar Balling Edwin Wolt Gerd Baumgaertel siemens ag Germany siemens ag Germany siemens ag Germany

＜正＞Worldwide installed power plant capacity is expected to increase from approximately 3500 GW in 1997 to about 4450GW by the year 2010[1].The share of fossil-fueled power plants will remain nearly constant at about 65%. However,within this part of the world’s power plan inventory,a dramatic change started ten years ago and will most likelycontinue during the coming *** the past more than half of the annual contract volume was awarded to steam powerplant concepts,compared to only one-third *** opposed to this,there was an increase in the number of gasturbine contract awards to about two-thirds of the entire volume,with a pronounced majority for combined-cycle *** in mind that the whole market expanded from an annual order volume of 70 GW to about 110 GW today,with a further rising trend anticipated,it stands to reason that gas turbines are almost sold out for the next two to threeyears.

关键词：

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Global Energy Interconnection 2018年第2期1卷 103-107页

作者： Thomas Hammer Rene Wimmer Karsten Loppach Ronny Fritsche Transformers Siemens EnergySiemens AG

1 Development of UHVDC transmission capabilities The economical development of China is closely connected with safe and reliable power *** centers *** central and eastern China need huge amounts of electrical *** energy resources and consumption areas are often distributed *** a consequence it is necessary to import electrical power to load center areas in an economic and efficient way.

关键词： UHVDC In Testing methods for 1100 kV UHVDC transformer

Filtered Backprojection Reconstruction with Depth-Dependent Filtering

在线全文

学校读者我要写书评

暂无评论

Tsinghua Science and Technology 2010年第1期15卷 17-24页

作者： Frank Dennerlein Holger Kunze Frédéric Noo siemens ag Healthcare SectorForchheim 91301Germany UCAIR Department of RadiologyUniversity of UtahSalt Lake CityUT 84108USA

A direct filtered-backprojection （FBP） reconstruction algorithm is presented for circular cone-beam computed tomography （CB-CT） that allows the filter operation to be applied efficiently with shift-variant band-pass characteristics on the kernel function. Our algorithm is derived from the ramp-filter based FBP method of Feldkamp et al. and obtained by decomposing the ramp filtering into a convolution involving the Hilbert kernel （global operation） and a subsequent differentiation operation （local operation）. The differentiation is implemented as a finite difference of two （Hilbert filtered） data samples and carried out as part of the backprojection step. The spacing between the two samples, which defines the low-pass characteristics of the filter operation, can thus be selected individually for each point in the image volume. We here define the sample spacing to follow the magnification of the divergent-beam geometry and thus obtain a novel, depth-dependent filtering algorithm for circular CB-CT. We evaluate this resulting algorithm using computer-simulated CB data and demonstrate that our algorithm yields results where spatial resolution and image noise are distributed much more uniformly over the field-of-view, compared to Feldkamp＇s approach.

关键词： computed tomography (CT) reconstruction filtered backprojection circular cone-beam CT

Online Stability Assessment in Control Room Environment

在线全文

学校读者我要写书评

暂无评论

Journal of Power and Energy Engineering 2014年第4期2卷 368-373页

作者： R. Krebs C. Heyde X.-P. Liang siemens ag Erlangen Germany siemens Ltd. Shanghai China

Power transmission systems are being operated closer to their stability limits compared to twenty years ago. As a result, an increasing risk of blackouts combined with extremely high costs economically and socially is observed. To reduce this risk the personnel in the control rooms of the transmission system operators have to be assisted by a system, which assesses the dynamic state of security online. The system presented in this paper is designed to investigate the security with regards to voltage stability, transient stability and small signal oscillatory stability. New technologies of visualizing the degree of stability to non dynamic stability experts are used as well as integration in existing SCADA/EMS systems are realized. The performance of the system is sufficiently high to be employed in the online environment of the control room.

关键词： DSA Dynamic Stability Situational Awareness Stability Monitoring Online Stability Secure Operation Limit SOL

电压预测技术提高HVDC混合实时仿真器接口稳定性

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

电力系统自动化 2000年第17期24卷 28-31页

作者：李函韩英铎王仲鸿 M.Claus H.Messner D.Retzmann G.Wild 清华大学电机系北京100084 siemens ag

介绍使用电压预测技术提高 HVDC混合实时仿真系统接口的稳定性。接口稳定性是建立混合实时仿真系统的关键问题。利用电压预测技术 ,结合“虚”阻尼并联支路 ,可以有效地减小接口电流噪声 ,提高 RTDS数值计算稳定性 ,保证数模接口在稳态... 详细信息

介绍使用电压预测技术提高 HVDC混合实时仿真系统接口的稳定性。接口稳定性是建立混合实时仿真系统的关键问题。利用电压预测技术 ,结合“虚”阻尼并联支路 ,可以有效地减小接口电流噪声 ,提高 RTDS数值计算稳定性 ,保证数模接口在稳态和暂态仿真中的稳定。各 AC/DC接口的电压预测步长需独立精心选择 ,典型值在 1个～ 3个步长 ,取决于直流平波电抗值的大小和直流输电线的长度。文中给出了接口的技术实现和性能校验结果。

关键词：接品电压预测 HVDC 实时数字仿真器电力系统

同方期刊数据库

The Energy Supply Chain Net

在线全文

学校读者我要写书评

暂无评论

Energy and Power Engineering 2013年第5期5卷 384-390页

作者： Albana Ilo siemens ag Austria Vienna Austria

The integration and the effective use of all available energy resourpces are possible only under a global view of the power systems. A holistic approach of the power system control, which includes all voltage levels f... 详细信息

关键词： Smart Grid Transmission Distribution High Voltage Medium Voltage Low Voltage Conservation Voltage Reduction Operator Role TSO DSO

Search/Match Using Full Trace Scans:A Strong Improvement over Using d/I Files

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Search/Match Using Full Trace Scans:A Strong Improvement ove...