检索结果-内蒙古大学图书馆

IEEE General Meeting Power& Energy Society

作者： Qi Jia Xinzhou Dong Shenxing Shi Xin He State Key Lab. of Control and Simulation of Power System and Generation Equipment Tsinghua University Beijing China Power Dispatching Control Center Guizhou Power Grid Co. Ltd Guiyang China

ISBN: (纸本)9781538677049

The traditional non-communication protection for distribution system is only applicable to fault feeders in neutral effectively grounded distribution system or the phase-to-phase fault feeders in neutral non-effectively grounded distribution system. For single-phase-to-ground fault feeders in the latter system, the protection will fail to operate because the magnitude of the current flow in the fault-to-ground connection is too small. To solve this problem, this paper presents a new non-communication protection compatible with the fault detection principle based on comparing the polarities of the initial voltage and current traveling waves. In this technique, when a single-phase-to-ground fault occurs, the relays which detect the fault is in the forward direction will operate based on the conventional time grading coordination at first, after one relay makes tripping decision which has the fastest time setting, the relay on the opposite side will detect the sound phase current changes in a time window to accelerate the operation. Extensive Electromagnetic Transients Program (EMTP) simulation studies with respect to a typical double end feeder system whose neutral is non-effectively grounded show that the proposed technique is able to fast and accurately remove a single-phase-to-ground fault line section from both ends.

关键词： Circuit faults Relays Acceleration Circuit breakers Wavelet transforms EMTP

来源：评论

学校读者我要写书评

暂无评论

Weather type partition method considering sequential features in photovoltaic forecasting

Weather type partition method considering sequential feature...

引用

6th International Conference on Renewable Power Generation

作者： Li, Hao Lu, Zongxiang Qiao, Ying Wang, Ningbo Ding, Kun State Key Lab. of Control and Simulation of Power Systems and Generation Equipments Department of Electrical Engineering Tsinghua University Haidian District Beijing100084 China Wind Power Technology Center Gansu Electric Power Corporation Lanzhou730050 China

The prediction method based on the partition of weather types has been widely used in photovoltaic prediction. Here, the temporal characteristics of PV data is studied, the physical meaning of the sequential difference sequences is analysed, and a characteristic index system including sequential characteristics index is proposed. The weather types are partitioned based on self-organising map neural network algorithm. Case study shows that the partition method is helpful to improve the discrimination of weather types and to improve prediction accuracy. © 2017 Institution of Engineering and Technology. All Rights Reserved.

关键词： Weather forecasting

来源：评论

学校读者我要写书评

暂无评论

A usage-based transmission cost allocation scheme considering impacts of DERs

A usage-based transmission cost allocation scheme considerin...

引用

2016 Tsinghua University-IET Electrical Engineering Academic Forum

作者： Wang, J.X. Zhong, H.W. Xia, Q. State Key Lab. of Control and Simulation of Power Systems and Generation Equipments Department of Electrical Engineering Tsinghua University Beijing China

ISBN: (纸本)9781785614170

With the rapid development of distributed energy resources (DERs), it is of vital importance to develop a well-designed transmission cost allocation scheme to reflect the contributions of DERs to the power system. In this paper, a usage-based transmission cost allocation scheme is proposed considering the capability of DERs. Based on the different intentions of transmission capacity, the transmission costs can be classified into four fractions: operating, contingency, planning and invalid transmission costs. On operating conditions, the transmission costs are identified and allocated according to the actual usage of consumers at each node. On contingency conditions, the transmission cost allocation will be influenced by the behaviors of DERs since DERs can provide emergent power support to help alleviate transmission congestion. On planning conditions, the transmission costs are useful in the future. The residual costs, i.e., the invalid transmission costs, should not allocated by consumers because this fraction is caused by the over investment of transmission owners. The case studies based on the IEEE 30-bus system validates the effectiveness of the proposed scheme and model. © 2016, Institution of Engineering and Technology. All rights reserved.

关键词： Investments

来源：评论

学校读者我要写书评

暂无评论

The fault simulation experiment and feature extraction of rolling bearing based on casing measuring point

The fault simulation experiment and feature extraction of ro...

引用

Joint Conference on Machinery Failure Prevention Technology Conference, MFPT 2016 and ISA's 62nd International Instrumentation Symposium, IIS 2016

作者： Han, Te Jiang, Dongxiang Wang, Nanfei State Key Lab. of Control and Simulation of Power System and Generation Equipments Department of Thermal Engineering Tsinghua University Beijing100084 China

In this paper, the reliability of the rolling bearing fault feature extraction based on casing vibration signals is discussed. Through the fault simulation experiment of rolling bearing, the vibration data of the outer ring fault, inner ring fault and rolling element fault, which respectively comes from bearing block measuring point and casing measuring point, is acquired. Then this paper analyzed the data from the time domain, frequency domain and amplitude domain. Analysis results show that, compared to the bearing block measuring points, due to the attenuation of the pulse signal of the fault in the transmission way and the increase of signal to noise on the casing, the fault features of casing vibration signals are significantly weakened. The envelope demodulation, FFT change on the vibration signal of casing directly cannot extract the fault characteristics. However the fault characteristic frequency can be extracted from the appropriate resonance frequency band. The results provide a reference for the fault feature extraction of rolling bearing based on the signal of casing. © 2016, Society for Machinery Failure Prevention Technology. All rights reserved.

关键词： Roller bearings

来源：评论

学校读者我要写书评

暂无评论

An Economic Evaluation of Electric Vehicle Charging Infrastructure in Public Places in China

引用

IOP Conference Series: Earth and Environmental Science 2018年第1期168卷

作者： Xueqi Huang Xiao Li Xinmei Yuan Bo He Juan Li State Key Lab. of Automotive Simulation and Control Jilin University Changchun China Department of Power Grid Development State Grid Energy Research Institute Beijing China State Grid Tianjin Electric Power Economic Technology Research Institute State Grid Tianjin Electric Power Company Tianjin China

The electric vehicle market has witnessed a big growth spurt as a result of the promotion of the transportation electrification in the global. Among electric vehicles, electric passenger cars are the most promising fleet to achieve the global climate target in the next decades, which will lead to a vast potential public charging market. Therefore, evaluating the economy of operating the charging infrastructure from the operator's perspective is especially required. The paper aims at providing an economic evaluation of charging infrastructure in public places in China. In the proposed method, the initial investment cost, the subsidy, the operating revenue and the operating cost are all modeled in detail. Using the proposed model, two scenarios representing the electric vehicle charging in the work place and in the fast charging station are assumed, and the cost and revenue of charging operators are calculated and compared. It is shown that under our assumption the payback period of the charging infrastructure in the work place is much shorter than that of fast charging station. Because the calculated payback period of fast charging station is more than ten years, current fast charging stations are unlikely to profit, and the promotion of the fast charging stations requires further policy support and smart grid technology development.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Measurement techniques on transient process of lightning striking overhead transmission lines

Measurement techniques on transient process of lightning str...

引用

CIGRE Session 46

作者： Xie, S.J. Li, J.M. Zhang, Y. Zeng, R. Zhuang, C.J. Wang, H. State Grid Sichuan Electric Power Research Institute State Grid Sichuan Electric Power Company China State Key Lab. of Control and Simulation of Power Systems and Generation Equipment Tsinghua University China

Obtaining the lightning strike density along an overhead transmission line and identifying the lightning strike types are the key to evaluating the lightning protection performance and proposing reasonable protection schemes of transmission lines. In addition, the waveform characteristics of lightning invasion overvoltage are the basis to establish the standard on the insulation tests of power equipment. Measuring the transient process of lightning striking overhead transmission lines is the basis to carry out the work mentioned above. In this paper, a distributed measurement method of transient current on conductors caused by lightning strikes is proposed. The measuring units are installed on the field conductors of transmission lines every 30 km to obtain less-distorted transient current waveforms. In order to enable measuring units to work in field isolated environment, a power supply coil using Faraday electric-magnetic effect and a wireless communication module is designed and developed. By far, 4776 measuring units have been installed on 597 transmission lines of China's power grid. According to measured transient current waveforms, the lightning strike point can be located using the double-end or single-end travelling wave location method, and the lightning strike type can also be identified. Moreover, a novel measurement method of lightning transient voltage based on the integrated optical electric field sensor (IOEFS) is proposed. In this method, the transient voltage waveforms are inversed from space electric field waveforms measured by IOEFSs. A series of performance tests of IOEFS have been carried out. The test results indicate that the response speed can reach several nanoseconds, and the frequency response can cover 5Hz∼100MHz which is wide enough for the measurement of the lightning transient voltage. In order to test the field measurement effect, the measurement equipment is used to measure a transient voltage when a group of capacitor voltage trans

关键词： Frequency response

来源：评论

学校读者我要写书评

暂无评论

Photoreactivity of Metal-Organic Frameworks in Aqueous Solutions: Metal Dependence of Reactive Oxygen Species Production

引用

Environmental Science and Technology 2016年第7期50卷 3634-3640页

作者： Liu, Kai Gao, Yanxin Liu, Jing Wen, Yifan Zhao, Yingcan Zhang, Kunyang Yu, Gang School of Environment Beijing Key Laboratory for Emerging Organic Contaminants Control State Key Joint Laboratory of Environmental Simulation and Pollution Control Tsinghua University Beijing100084 China MOE Key Lab. of Environmental Remediation and Ecosystem Health College of Environmental and Resource Sciences Zhejiang University Hangzhou310058 China Lyles School of Civil Engineering Division of Environmental and Ecological Engineering Purdue University West LafayetteIN47907 United States

Promising applications of metal-organic frameworks (MOFs) in various fields have raised concern over their environmental fate and safety upon inevitable discharge into aqueous environments. Currently, no information regarding the transformation processes of MOFs is availab.e. Due to the presence of repetitive π-bond structure and semiconductive property, photochemical transformations are an important fate process that affects the performance of MOFs in practical applications. In the current study, the generation of reactive oxygen species (ROS) in isoreticular MIL-53s was studied. Scavengers were employed to probe the production of 1O2, O2•-, and •OH, respectively. In general, MIL-53(Cr) and MIL-53(Fe) are dominated by type I and II photosensitization reactions, respectively, and MIL-53(Al) appears to be less photoreactive. The generation of ROS in MIL-53(Fe) may be underestimated due to dismutation. Further investigation of MIL-53(Fe) encapsulated diclofenac transformation revealed that diclofenac can be easily transformed by MIL-53(Fe) generated ROS. However, the cytotoxicity results implied that the ROS generated from MIL-53s have little effect on the viability of the human hepatocyte (HepG2) cell line. These results suggest that the photogeneration of ROS by MOFs may be metal-node dependent, and the application of MIL-53s as drug carriers needs to be carefully considered due to their high photoreactivity. (Chemical Equation Presented). © 2016 American Chemical Society.

关键词： Photoreactivity

来源：评论

学校读者我要写书评

暂无评论

Based on DSPACE vehicle diesel engine transient operating conditions

Based on DSPACE vehicle diesel engine transient operating co...

引用

International Symposium on Computer, Consumer and control

作者： Qiang Liu ZhongChang Liu Jing Tian Jun Wang Jian Fang Key Lab. of Automobile Simulation & Control Jilin Univ. Changchun China Jilin Eng. Normal Univ. Changchun China

ISBN: (纸本)9781509030729

With the requirement of the emission regulations for the transient working condition of the vehicle diesel engine and the increasing demand of the public to the energy saving, the optimization of the transient performance of the engine based on DSPACE is very important. To this end, this study carried out on a turbocharged diesel engine under transient operating conditions of the test and analysis of combustion deterioration phenomenon and through the DSPACE to adjust the injection parameters to achieve the control of combustion deterioration test. Experimental results show that compared with the steady state, transient operating conditions due to the delay of gas, combustion engine exist obvious deterioration, including lagged CA10 and CA50, smoke and specific fuel consumption increased;but with the fuel injection timing advance, eliminates transients in the process of CA10 and CA50 lag phenomenon, improve the effective thermal efficiency of the engine, but the smoke and NO_x emissions have risen;fuel injection pressure on the impact of transient combustion also significantly, when the injection pressure increases, CA10 and CA50 hysteresis weakened, smoke value decreased, while NO_x emission increases;transient engine thermal efficiency with the rise in fuel injection pressure increased at first, and then decreased.

关键词： DSPACE Vehicle diesel engine Transient condition Combustion deterioration Fuel injection parameters Optimization

来源：评论

学校读者我要写书评

暂无评论

Diesel Engine SCR control: Current Development and Future Challenges

引用

Emission control Science and Technology 2015年第2期1卷 121-133页

作者： Yuan, Xinmei Liu, Hongqi Gao, Ying State Key Lab. of Automotive Simulation and Control Jilin University ChangchunJilin130025 China

To meet increasingly stringent emission legislations, selective catalytic reduction (SCR) becomes an essential aftertreatment technique. This paper presents a comprehensive overview of the current development and future challenges of SCR control technologies. In this paper, SCR system hardware configurations are introduced, modeling and calibration of the SCR converter are provided, and current control strategies are summarized and reviewed. Finally, primary areas driving the future of SCR control research are discussed. © 2015, Springer SIP, AG.

关键词： Selective catalytic reduction

来源：评论

学校读者我要写书评

暂无评论

Development of low cost hardware-in-the-loop test system and a case study for electric vehicle controller

Development of low cost hardware-in-the-loop test system and...

引用

International Conference on Applied System Innovation (ICASI)

作者： Jing Lin Xia Qinghua Diao Wei Sun Zengzhen Xing Xinmei Yuan Tingting Dong State Key Lab.of Automotive Simulation and Control Jilin University Changchun Jilin China Geely Automobile Institute Hangzhou Zhejiang China

ISBN: (纸本)9781467398893

In recent years, hardware-in-the-loop (HIL) test becomes an effective approach in the design of automotive electronics. One issue of HIL system is that most commercial HIL products are very expensive. With careful analysis of the ECU functionality and reasonable use of the hardware resources, it is possible to realize a HIL system to fully satisfy the test requirements with much lower cost in many cases. In this paper, the possibilities to reduce the cost of current HIL systems are discussed. As a case study, the development of a low cost HIL system for a pure electric vehicle controller is presented, the modeling of the vehicle is introduced and the hardware and software implementations are given. Finally, the feasibility of the proposed HIL system is validated by experimental results.

关键词： Decision support systems control systems Industrial electronics

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：