检索结果-内蒙古大学图书馆

16th International Conference on Fracture and Damage Mechanics, 2017

作者： Han, Te Jiang, Dongxiang Yang, Wenguang State Key Lab of Control and Simulation of Power Systems and Generation Equipment Department of Thermal Engineering Tsinghua University Beijing100084 China

ISBN: (纸本)9783035711684

Degradation state assessment of bearing is an important part of prognostic and health management (PHM) in rotating machinery. Generally, the energy distribution of frequency band is sensitive to degradation state for rolling bearing. Hence, a novel assessment method based on variational mode decomposition (VMD) and energy distribution is proposed in this work. Firstly, the VMD is used to decompose raw vibration signal into several components with different scales and frequency bands. These components is capable of reflecting the local characteristic of vibration signal. Then, the energy distribution of these components is utilized as feature vector. Finally, the different bearing states can be classified by the scatter plots of the first several principal components after principal component analysis (PCA). The analysis of an experimental dataset demonstrates the effectiveness of this methods. The comparative analysis shows the VMD is superior to traditional empirical mode decomposition (EMD) methods. © 2017 Trans Tech Publications, Switzerland.

关键词： Variational mode decomposition

来源：评论

学校读者我要写书评

暂无评论

An Internet of Energy Things Based on Wireless LPWAN

引用

Engineering 2017年第4期3卷 460-466页

作者： Yonghua Song Jin Lin Ming Tang Shufeng Dong State Key Laboratory of Control and Simulation of Power Systems and Generation Equipment Department of Electrical Engineering Tsinghua University. Beijing 100084 China College of Electrical Engineering Zhejiang University Hangzhou 310027 China Center of Internet of Energy Things Tsinghua-Sichuan Energy Internet Institution Chengdu 610213 China

Under intense environmental pressure, the global energy sector is promoting the integration of renewable energy into interconnected energy systems. The demand-side management （DSM） of energy systems has drawn considerable industrial and academic attention in attempts to form new flexibilities to respond to variations in renewable energy inputs to the system. However, many DSM concepts are still in the experimental demonstration phase. One of the obstacles to DSM usage is that the current information infrastructure was mainly designed for centralized systems, and does not meet DSM requirements. To overcome this barrier, this paper proposes a novel information infrastructure named the lnternet of Energy Things （IoET） in order to make DSM practicable by basing it on the latest wireless communication technology： the low-power wide-area network （LPWAN）. The primary advantage of LPWAN over general packet radio service （GPRS） and area Internet of Things （loT） is its wide-area coverage, which comes with minimum power consumption and maintenance costs. Against this background, this paper briefly reviews the representative LPWAN tech- nologies of narrow-band Internet of Things （NB-IoT） and Long Range （LORa） technology, and compares them with GPRS and area IoT technology. Next, a wireless-to-cloud architecture is proposed for the IoET, based on the main technical features of LPWAN. Finally, this paper looks forward to the potential of IoET in various DSM application scenarios.

关键词： Low-power wide-area network Internet of Things Narrow-band lnternet of Things LoRa technology Demand-side management

来源：评论

学校读者我要写书评

暂无评论

Progress of the 4 K-class Vuilleumier type cryocooler and its further applications

引用

IOP Conference Series: Materials Science and Engineering 2020年第1期755卷

作者： J Wang C Z Pan T Zhang K Q Luo X T Xi L B Chen Y Zhou J J Wang CAS Key Laboratory of Cryogenics Technical Institute of Physics and Chemistry Beijing 100190 China University of Chinese Academy of Science Beijing 100049 China Laboratoire national de métrologie Et d'essais-Conservatoire national des arts et métiers (LNE-Cnam) F-93210 La Plaine France State Key Lab of Control and Simulation of Power Systems and Generation Equipment Tsinghua University Beijing 100084 China

Vuilleumier cycle was first patented in 1918. It was usually regard as the thermal-driven Stirling refrigeration cycle, which combined the low-frequency working pattern like Giffod-Mcmahon (GM) cryocooler and the compactness of Stirling-type cryocooler. With the continuous development in the past 100 years, the Vuilleumier-type (VM-type) cryocoolers have to been proved to generate cooling power from ambient temperature to liquid nitrogen temperature and even to liquid helium temperature. In recent decades, some efforts were made on traditional displacer-type VM cryocooler, Vuilleumier hybrid pulse tube cryocooler (VM-HPTC) and the VM-type pulse tube cryocooler (VM-type PTC) to obtain the liquid helium temperature. Successfully, not only the 4 K was obtained, but also the limit temperature of oscillating cryocooler by He4 was hit. This paper presents the progress of the 4 K-class VM-type cryocooler and analyzed the possible applications of 4 K class VM-type cryocooler.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Near-real-time monitoring of global CO2 emissions reveals the effects of the COVID-19 pandemic (vol 11, 5172, 2020)

引用

NATURE COMMUNICATIONS 2020年第1期11卷 5172页

作者： Liu, Zhu Ciais, Philippe Deng, Zhu Lei, Ruixue Davis, Steven J. Feng, Sha Zheng, Bo Cui, Duo Dou, Xinyu Zhu, Biqing Guo, Rui Ke, Piyu Sun, Taochun Lu, Chenxi He, Pan Wang, Yuan Yue, Xu Wang, Yilong Lei, Yadong Zhou, Hao Cai, Zhaonan Wu, Yuhui Guo, Runtao Han, Tingxuan Xue, Jinjun Boucher, Olivier Boucher, Eulalie Chevallier, Frederic Tanaka, Katsumasa Wei, Yiming Zhong, Haiwang Kang, Chongqing Zhang, Ning Chen, Bin Xi, Fengming Liu, Miaomiao Breon, Francois-Marie Lu, Yonglong Zhang, Qiang Guan, Dabo Gong, Peng Kammen, Daniel M. He, Kebin Schellnhuber, Hans Joachim Department of Earth System Science Tsinghua University Beijing China. zhuliu@***. Laboratoire des Sciences du Climat et de l'Environnement LSCE CEA CNRS UVSQ Centre d'Etudes Orme de Merisiers Gif-sur-Yvette France. Department of Earth System Science Tsinghua University Beijing China. Department of Meteorology and Atmospheric Science The Pennsylvania State University University Park PA USA. Department of Earth System Science University of California Irvine 3232 Croul Hall Irvine CA USA. Division of Geological and Planetary Sciences California Institute of Technology Pasadena CA USA. Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control Collaborative Innovation Center of Atmospheric Environment and Equipment Technology School of Environmental Science and Engineering Nanjing University of Information Science & Technology Nanjing China. Key Laboratory of Land Surface Pattern and Simulation Institute of Geographical Sciences and Natural Resources Research Chinese Academy of Sciences Beijing China. Climate Change Research Center Institute of Atmospheric Physics Chinese Academy of Sciences Beijing China. Key Laboratory of Middle Atmosphere and Global Environment Observation Institute of Atmospheric Physics Chinese Academy of Sciences Beijing China. School of Environment Tsinghua University Beijing China. School of Mathematical School Tsinghua University Beijing China. Department of Mathematical Sciences Tsinghua University Beijing China. Center of Hubei Cooperative Innovation for Emissions Trading System Wuhan China. Institut Pierre-Simon Laplace Sorbonne Université / CNRS Paris France. Université Paris Dauphine Place du Maréchal de Lattre de Tassigny 75016 Paris France. Center for Energy and Environmental Policy Research Beijing Institute of Technology Beijing China. Department of Electrical Engineering the State Key Lab of Control and Simulation of Power Systems and Generation Equipment Institute for National Governance and G

A Correction to this paper has been published: https://***/10.1038/s41467-020-20254-5

关键词： Climate sciences Atmospheric science Environmental sciences Environmental social sciences

来源：评论

学校读者我要写书评

暂无评论

Modeling and simulation of air-gapped current transformer based on Preisach Theory

引用

Protection and control of Modern power systems 2017年第1期2卷 111-121页

作者： Ya Hui Wu Xin Zhou Dong Sohrab Mirsaeidi State Key Laboratory of Control and Simulation of Power Systems and Generation Equipment Department of Electrical EngineeringTsinghua UniversityBeijing 100084China

Current Transformer(CT)modeling,by which CT’s characteristics can be studied has a significant importance in CT selection and *** spite of numerous studies about closed-core CT model,only a few works have been conducted on air-gapped ones with the following problems:models of which required data is easily-accessible,have poor simulations of magnetization process;on the contrary,models which have satisfactory simulations,are hard to be established because of the hard-to-get required ***,based on Preisach Theory,a novel air-gapped CT model is deduced from the closed core CT *** proposed model is accurate and can be established *** saturation and remanence properties of closed-core CT and air-gapped CT are simulated and compared.

关键词： CT modeling Air gap Preisach Theory Saturation Remanence

来源：评论

学校读者我要写书评

暂无评论

Exploration on the value innovation of Energy Internet demonstration park

Exploration on the value innovation of Energy Internet demon...

引用

IEEE Conference on Energy Internet and Energy System Integration

作者： Lin Cheng Ning Qi Liting Tian Rong Li Shumin Sun State Key Laboratory of Control and Simulation of Power Systems and Generation Equipment Tsinghua University Beijing China State Grid Shandong electric power company Shandong China

With the rapid development of Energy Internet, Energy Internet demonstration park has become the focus of international academy and industry. In this paper, main characteristics and objectives of Energy Internet demonstration park are analyzed and the architecture of Energy Internet demonstration park composed of the physical layer, information layer, and operation layer has been proposed. Moreover, both the old and new value of multi-energy complementary is summarized and discussed. Finally, numerical analysis of the demonstration Park is used to explore the value innovation mentioned above.

关键词： Energy internet Demonstration park Value innovation Multi-energy complementary Practice exploration

来源：评论

学校读者我要写书评

暂无评论

Flexible unbalanced control with peak current limitation for virtual synchronous generator under voltage sags

Flexible unbalanced control with peak current limitation for...

引用

“紫金论电”2017智能电网保护和运行控制国际学术研讨会

作者： Tianwen ZHENG Laijun CHEN Yan GUO Shengwei MEI State Key Laboratory of Control and Simulation of Power Systems and Generation Equipments Department State Key Laboratory of Control and Simulation of Power Systems and Generation Equipments Department

Virtual synchronous generator(VSG)is grid-friendly for integrating distributed generations(DGs)since it can emulate the operation mechanism of traditional synchronous generator(SG).However,the traditional VSG control strategy,which is mainly suitable for balanced voltage conditions,may lead to power oscillations,current unbalance and even overcurrent under unbalanced voltage *** overcome this difficulty,a flexible unbalanced control with peak current limitation for VSG under unbalanced operating conditions is *** on the basic VSG control algorithm,the control strategy integrates two novel control modules,which are current reference generator(CRG)and power reference generator(PRG).The proposed control strategy can flexibly meet different operation demands,which includes current balancing,constant active or reactive *** the injected currents are kept within safety values for a better utilization of the VSG power ***,the experimental platform is *** results demonstrate the validness and effectiveness of the proposed control strategy.

关键词： Virtual synchronous generator Unbalanced control Current reference generator power reference generator Voltage sags

来源：评论

学校读者我要写书评

暂无评论

Unit commitment considering demand response behavior based on utility maximization

Unit commitment considering demand response behavior based o...

引用

2017 IEEE Conference on Energy Internet and Energy System Integration, EI2 2017

作者： Zhang, Yumin Han, Xueshan Xu, Bo Zhang, Li Sun, Donglei Miao, Xiaofeng Jiang, Jiayin Key Laboratory of Power System Intelligent Dispatch and Control of Ministry of Education Shandong University Jinan China State Key Laboratory of Control and Simulation of Power Systems and Generation Equipment Department of Electrical Engineering Tsinghua University Haidian District Beijing100084 China Economic and Technology Research Institute of State Grid Shandong Electric Power Company Jinan China State Grid Shandong Electric Power Company Yantai Electric Power Company Yantai264001 China

ISBN: (纸本)9781538614273

The active participation of demand side resources in power grid operation not only benefits the individual participant but also benefits the whole system. The optimal goal can promote by excavating the active behaviors of demand side. The welfare maximization of market participant is the driving force of such active behaviors. Considering the independence of each user's behavior, the consumer's utility function is selected to depict consumer's preference and demand response behavior. In order to coordinate the consumers' maximum welfare with social welfare maximization, consumers' utility function and units' operation cost are integrated into Unit Commitment (UC) model. The objective function is to maximize social welfare, by subtracting units' operation cost from consumers' total utility, and this objective can be acquired. Considering the proposed model should be solved in a distributed manner, the idea of the centralized coordination and the decentralized decision-making is proposed. Based on the Lagrangian relaxation (LR) principle and distributed real-time pricing scheme, a closed-loop feedback mechanism is constructed to reflect the relationship among generator output, price level, and load demand. The ten generating units example can illustrate the effectiveness of the proposed method. © 2017 IEEE.

关键词： power markets

来源：评论

学校读者我要写书评

暂无评论

Modeling and analysis of secondary controlled virtual synchronous generator with dynamic droop for microgrid

Modeling and analysis of secondary controlled virtual synchr...

引用

2017 IEEE Conference on Energy Internet and Energy System Integration, EI2 2017

作者： Yan, Weihang Gao, David Wenzhong Zhang, Fang Cheng, Lin Yan, Shijie Department of Electrical and Computer Engineering University of Denver Denver United States State Key Laboratory of Control and Simulation of Power Systems and Generation Equipment Tsinghua University Beijing China College of Information Science and Technology Northeastern University Shenyang China

ISBN: (纸本)9781538614273

In this paper, a dynamic droop mechanism is proposed to damp the synchronizing oscillation that exists in a virtual synchronous generator based distributed generator system without varying the steady-state active-power-loop droop coefficient. In order to eliminate the steady-state error introduced due to load changes or generator trips, a distributed secondary controller based on extremum seeking is employed so that microgrid frequency can be restored to nominal value. Besides, the small-signal model of virtual synchronous generator system is presented under d-q reference frame where virtual synchronous generator is deployed as a PV node. Moreover, the linearized system model of virtual synchronous generator with dynamic droop mechanism is derived and its advantage is discussed. Finally, a modified IEEE 14 bus microgrid system is established in Matlab/Simulink platform. simulation results demonstrate the validity and feasibility of the proposed method. © 2017 IEEE.

关键词： Dynamics

来源：评论

学校读者我要写书评

暂无评论

Review on distribution network planning methods considering large-scale access of flexible load

Review on distribution network planning methods considering ...

引用

IEEE Conference on Energy Internet and Energy System Integration

作者： Weihong Yang Lin Cheng Ning Qi Yanru Liu Xuyang Wang State Power Economic Research Institute State Grid Corporation of China Beijing China State Key Laboratory of Control and Simulation of Power Systems and Generation Equipment Tsinghua University Beijing China

With the rapid development of active distribution network and demand-side response, the effective utilization of large-scale flexible load is one of the main trends of the future distribution network development. In this paper, Energy Internet demonstration park has become the focus of international academy and industry. In this paper, shortcomings of the existing methods and new methods in load forecasting, power, and energy balance and planning evaluation are proposed, which emphasize mostly on the impact of flexible load on the distribution network. Then, the planning optimization method considering flexible load is discussed, and the relevant theoretical results are summarized from the aspect of uncertainty, multi-objective and multi-agent. Finally, the relevant technologies of future distribution network planning are prospected.

关键词： Distribution network planning Flexible load Active distribution network Planning method

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：