检索结果-内蒙古大学图书馆

2017 International Conference on Mechanical and Mechatronics Engineering(ICMME2017)

作者： Zhu-wen OU Jin-bo WU Hong-jun ZHEN Zhan-qing YU Jin-liang HE Qingyuan Power Supply Bureau of Guangdong Power Grid Co. LTD State Key Lab.of Control and Simulation of Power Systems and Generation Equipment Department of Electrical EngineeringTsinghua University

Parallel gaps,as a new mode of "channel" type lightning protection,can do it with the sub insulator arc distance to effectively protect the insulator,but the corresponding line tripping rate will be affected because of this;Development method based on the leader in this paper the calculation method of the lightning path,the typical used tower of guangzhou trip rate change after the application of parallel gap situation has carried on the analysis,got a short distance and adopt reasonable reinforced insulation,the trip rates did not rise significantly.

关键词： Parallel gaps A lightning strike tripping rate Insulation coordination

来源：评论

学校读者我要写书评

暂无评论

The Research of Asymmetric Parallel Gaps in EHV Transmission Lines

The Research of Asymmetric Parallel Gaps in EHV Transmission...

引用

2017 2nd International Conference on Electrical and Electronics: Techniques and Applications（EETA2017）

作者： Jin-bo WU Zhan-qing YU Hong-jun ZHEN Chao SU Rong ZENG Jin-liang HE State Key Lab.of Control and Simulation of Power Systems and Generation Equipment Department of Electrical Engineering Tsinghua University Electric Power Science Institute of Yunnan Power Grid Co. Ltd

As a new kind of lightning protection, parallel gaps have simple structure, easy installation, good economy, and many other advantages. The traditional parallel gap due to the large short distance, can lead to lightning trip-out rate increases. Based on arc movement characteristics this paper presents a design of new type of parallel gaps and the analysis of the surface field strength, and the verification test, design a new kind of parallel gap are obtained.

关键词： Arc movement Parallel gaps Surface electrical field

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

Realization and Application of PSASP-MATlab Associated Mixed Step simulation based on Engine Calling Mode

Realization and Application of PSASP-MATLAB Associated Mixed...

引用

2017 International Electrical and Energy Conference (CIEEC 2017)

作者： Yiming ZHANG Qinglai GUO Wenlu ZHAO Tian XIA Haoqing XIONG Ran SUN Henan Electric Power Dispatching and Control Center State Grid Corporation of China(SGCC) State Key Lab of Control and Simulation of Power Systems and Generation Equipment Department of Electrical Engineering Tsinghua University Energy Internet Research Institute Tsinghua University

By calling MATlab calculation engine function library,associated simulation between power System Analysis Software Package(PSASP) and MATlab can be realized in parallel and serial *** could use different timing sequence from PSASP,and mixed step simulation can be *** calculation method was used in a 10-nodes power system case for the modeling and simulation of Automatic Voltage Regulator(AVR),and the correctness of the proposed approach is *** this foundation,the electromechanical transient model of Static Var Generator(SVG) was founded with MATlab/Simulink,and it is of universal applicability and *** inner inverter model can also be used in general grid-connection simulating models of wind power generator,photovoltaic generation,energy storage,***,simulation and analysis for grid-connected wind farm by introducing the SVG model into PSASP were carried out via the proposed associated simulation method above,and the correctness of the model is verified via the calculation *** research results can be used to do assistant analysis for reactive voltage of grid-connected new energy power generation.

关键词： PSASP MATlab engine static var generator reactive voltage mixed step simulation

来源：评论

学校读者我要写书评

暂无评论

Diagnosis method for rub-impact fault of rotating machinery based on EMD and Hilbert envelop spectrum

Diagnosis method for rub-impact fault of rotating machinery ...

引用

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

作者： Wang, Nan-Fei Jiang, Dong-Xiang Han, Te State Key Laboratory of Control and Simulation of Power System and Generation Equipments Departments of Thermal Engineering Tsinghua University Beijing100084 China

Aiming at the characteristics of the casing vibration acceleration signal of rotating machinery with rubbing fault, a diagnosis method based on EMD (empirical mode decomposition) and Hilbert envelop spectrum is put forward. When the rubbing fault occurs between the rotor and the stator, the vibration acceleration signals from the casing of the rooting machinery will present amplitude-modulated feature due to the periodical rub-impact between the rotor and the stator. However, it is relatively difficult to extract the rub-impact feature since the rub-impact signal in the process of transferring to the casing is always buried in the noise and background signals. In this paper, by means of the powerful capability of EMD and Hilbert envelop spectrum in processing nonlinear signal can accurately describe nonlinear behaviours, the fault signal is adaptively decomposed by EMD to acquire intrinsic mode functions (IMF) containing obvious feature of amplitude modulation. Then some of the sensitive IMF components are transformed by FFT and their Hilbert spectrum are analysed. The analysis results from the experimental signal show that the EMD provides an effective and adaptive method to obtain 'purified' casing vibration acceleration signal, which demonstrates the transient casing vibration more precisely and vividly, decreasing misinterpretation of the machine running condition. Therefore, the EMD approach can be applied to the single-point rubbing fault diagnosis of the rotor systems efficiently. © 2016, Society for Machinery Failure Prevention Technology. All rights reserved.

关键词： Empirical mode decomposition

来源：评论

学校读者我要写书评

暂无评论

Voltage balance optimisation among subsystems of wind-photovoltaic-ES hybrid generating system

引用

The Journal of Engineering 2017年第13期2017卷 854-858页

作者： Han Wu Yan Li Zongxiang Lu Haiyan Tang State Key Lab of Control and Simulation of Power Systems and Generation Equipments (Dept. of Electrical Engineering Tsinghua University) Haidian District Beijing 100084 People's Republic of China North China Electric Power Research Institute Co. Ltd Beijing 100045 People's Republic of China State Key Laboratory of Operation and Control of Renewable Energy & Storage Systems (China Electric Power Research Institute) Haidian District Beijing 100192 People's Republic of China

Wind-photovoltaic-energy storage (ES) hybrid generating system has numerous reactive power sources. It is crucially important for coordinated control of these reactive power sources. According to the test results, there are unbalanced control problem in subsystem voltage of the hybrid generating system. The problem caused reactive power circulation and loop current. A subsystem voltage balance optimisation strategy is proposed to solve the problem. The case study shows the efficiency of the proposed strategies.

关键词： electric potential wind power photovoltaic power systems reactive power electric power generation reactive power sources wind-photovoltaic-ES hybrid generating system subsystems voltage balance optimisation

来源：评论

学校读者我要写书评

暂无评论

Electrical tree initiation and propagation in silicone rubber under long-term AC aging

Electrical tree initiation and propagation in silicone rubbe...

引用

2016 IEEE Conference on Electrical Insulation and Dielectric Phenomena, CEIDP 2016

作者： Zhang, Yunxiao Zhou, Yuanxiang Zhang, Ling Ming, Chen Zhang, Xu Yanchao, Sha State Key Lab of Control and Simulation of Power Systems and Generation Equipments Department of Electrical Engineering Tsinghua University Beijing100084 China North China Electric Power Research Institute Co Ltd. Beijing100045 China

ISBN: (纸本)9781509046546

Electrical tree break-down is the major failure problem in cable accessories, however, mechanisms of the electrical tree initiation and propagation are still lack of deeply research, especially in silicone rubber (SIR) which is widely used as insulation material for cable accessories. Long-term aging (0- 1000 h) experiments under the different voltages were conducted to observe electrical tree initiation and propagation processes. In trees initiation stage, with increasing of applied voltage, electrical tree initiation probability becomes larger, while tree initiation time dramatically decreases. The experiment observations demonstrated four shapes of trees which are dominated. As applied voltage increasing, the numbers of electrical trees life-cycles increased and exponential relationship was found between tree length and magnitude of applied voltage. It is noted that charges, whose energy exceeding a certain critical value, destroy microstructure of dielectric accumulatively via injection and extraction, and cause electrical trees initiate when it accumulates to a visible extent. © 2016 IEEE.

关键词： Life cycle

来源：评论

学校读者我要写书评

暂无评论

Repeated Strike Process During Disconnector Operation in Ultra-High Voltage Gas-Insulated Switchgear

引用

Plasma Science and Technology 2016年第3期18卷 247-253页

作者：关永刚蔡元纪陈维江刘卫东李志兵岳功昌张俊民 State Key Lab of Control and Simulation of Power System and Generation Equipments Department of Electrical EngineeringTsinghua UniversityBeijing 100084China State Grid Corporation of China Beijing 100031China China Electric Power Research Institute Beijing 100192China School of Automation Science and Electrical Engineering Beihang UniversityBeijing 100191China

Very fast transient over-voltage （VFTO）, induced by disconnector operations in gas- insulated switchgears, has become the limiting dielectric stress at ultra-high voltage levels. Much work has been done to investigate single-strike waveforms of VFTO. However, little study has been carried out investigating the repeated strike process, which would influence VFTO significantly. In this paper, we carried out 450 effective experiments in an ultra-high voltage test circuit, and conducted calculations through the Monte Carlo simulation method, to investigate the repeated strike process. Firstly, the mechanism of the repeated strike process is proposed, based on the ex- perimentai results. Afterwards, statistical breakdown characteristics of disconnectors are obtained and analyzed. Finally, simulations of the repeated strike process are conducted, which indicate that the dielectric strength recovery speed and polarity effect factor have a joint effect on VFTO. This study enhances the understanding of the nature of VFTO, and may help to optimize the disconnector designed to minimize VFTO.

关键词： disconnector （DS） repeated strike process discharge statistical breakdowncharacteristics ultra-high voltage （UHV） very fast transient over-voltage （VFTO）

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

A Corrective Security-Constrained Optimal power Flow Method for AC/DC Hybrid systems Based on MMC-HVDC

A Corrective Security-Constrained Optimal Power Flow Method ...

引用

IEEE Conference on Energy Internet and Energy System Integration

作者： Yi Lin Yu-chen Tang Liu-qing Qiu Ming-ye Zhang Yu-tao Ju State Grid Fujian Power Economic Research Institute State Key Laboratory of Control and Simulation of Power Systems and Generation Equipments Tsinghua University College of Information and Electrical Engineering China Agricultural University

ISBN: (纸本)9781538614280

This paper presents an optimal power flow (OPF) model for AC/DC meshed networks with Modular Multilevel Converter based High Voltage Direct Current (MMC-HVDC) system. The OPF problem is formulated to minimize the total network loss of the whole AC/DC grids by adjusting generators and modular multilevel converters considering N-1 constraints and post-contingency corrective control. A practical method is proposed to handle N-1 static security constraints and corrective control with OPF more effectively. simulations are conducted on IEEE 39-bus testing system and a practical power grid. The results demonstrate the effectiveness of the approach.

关键词： Modular Multilevel Converter HVDC Optimal power flow Interior point method N-1 static security constraints Corrective control

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：