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International Conference on Wireless Communications and Signal Processing (WCSP)

作者： Xinyi Wang Yuanxin Sun Huogen Yu Ting Feng Wanbin Tang Ying Zhang National Key Laboratory of Science and Technology on Communications University of Electronic Science and Technology of China Science and Technology on Information Transmission and Dissemination in Communication Networks Laboratory State Grid Sichuan Electric Power Company

ISBN: (纸本)9781467376884

In this paper, we consider amplify-and-forward cognitive relay networks in a spectrum-sharing environment. We present the performance analysis under two different partial relay selection (PRS) schemes, namely source-relay partial relay selection (SR-PRS) and relay-destination partial relay selection (RD-PRS). Specifically, we consider interference power constraint on secondary source and relay nodes, and transmit power constraint on secondary relay nodes. In this context, the exact outage probability is derived over Rayleigh fading channels. Our results show that the system performance is dominated by the power constraints and the number of secondary relay nodes. Moreover, we provide simulation results to compare the two different PRS schemes. Finally, Monte Carlo simulations are shown to validate the accuracy of the analytical results.

关键词： Interference Signal to noise ratio Performance analysis Relay networks (telecommunications) Context Simulation

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An improved thermal network model of the IGBT module for wind power converters considering the effects of base plate solder fatigue

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IOP Conference Series: Earth and Environmental Science 2016年第1期40卷

作者： H Li Y G Hu S Q Liu Y Li X L Liao Z X Liu The State Key Laboratory of Power Transmission Equipment & System Security and New Technology (Chongqing University) Chongqing China The State Grid Jiangxi Electric Power Corporation Ganzhou Power Supply Company Ganzhou China Chongqing KK-QIANWEI Wind Power Equipment Co. Ltd Chongqing China

This study presents an improved thermal network model of the IGBT module that considers the effects of base plate solder fatigue on the junction temperature of the said module used in wind power converters. First, the coupling thermal structure 3D finite element model of the IGBT module is established based on the structure and material parameters of the module used in the wind power converters of a doubly fed induction generator. The junction temperature of the module is also investigated at different thermal desquamating degrees of the base plate solder. Second, the thermal resistance parameters are determined at different desquamating degrees, and the improved thermal network model that considers the effects of base plate solder fatigue is established. Finally, the two results of the calculation of the junction temperature are compared in different fatigue stages through the improved thermal network model and the 3D finite element model, which testify to the effectiveness of the improved thermal network model.

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Comprehensive evaluation on user energy efficiency based on improved matter-element model

Comprehensive evaluation on user energy efficiency based on ...

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International Conference on Electric Utility Deregulation and Restructuring and power Technologies (DRPT)

作者： Huan Liu Ciwei Gao Fuchao Liu Yongjun Han Jianhua Zhang Jiangsu Provincial Key Laboratory of Smart Grid Technology & Equipment Southeast University Nanjing China Southeast University Chengxian College Nanjing China Electrical Power Research Institute of State Grid Gansu Power Company Lanzhou China

According to the influence factors of energy efficiency digged from user energy data, this paper establishes a multilevel energy efficiency evaluation system considering equipment and users on the whole. Objective and subjective weighting method is adopted to balance the influence of subjective and objective factors. Matter-element extension model is used to build a hierarchy of energy efficiency indicators to form user's electric energy efficiency grades. Analyzing assessment results based on this model can reflect the energy efficiency level of the user, and offer users help in energy management and tap the energy saving potential.

关键词： Indexes Energy efficiency power industry Decision support systems Data models Sensitivity analysis

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Practical online detection of internal winding faults of EHV shunt reactors based on impulse frequency response analysis

Practical online detection of internal winding faults of EHV...

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International Conference on Pulsed power

作者： Z. Zhao C. Yao C. Li Y. Mi B. Luo L. Zou Y. Liao State Key Laboratory of Power Transmission Equipment System Security and New Technology Chongqing University Chongqing China China Southern Power Grid Electric Power Research Institute Guangzhou Guangdong China

Internal winding faults of extra-high voltage (EHV) shunt reactors could be a serious threaten to the normal operation of power grid. Initial winding faults could develop into catastrophic failure, resulting in sudden outage of equipment and significant economic losses. It is necessary to implement online detection method to evaluate the status of properties. This paper proposed a practical method for online detecting the internal winding faults of EHV shunt reactors; it is based on impulse frequency response analysis. The basic principle and the detection devices of the method were introduced, respectively. Then the original frequency response curves of EHV shunt reactors were obtained through field online tests, at last, the offline winding fault simulation test was carried out to further investigate the proposed method. This paper is a contribution for the application of impulse frequency response analysis on high voltage equipment.

关键词： Inductors Windings Shunts (electrical) Circuit faults Frequency response Insulators Voltage measurement

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Effects of Atmospheric Pressure on Tracking Failure of Epoxy/SiO_2 Nanocomposite

Effects of Atmospheric Pressure on Tracking Failure of Epoxy...

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IEEE International Conference on Applied Superconductivity and Electromagnetic Devices

作者： Ji Wei Zhang Qing Quan Li Ang Ren Bo Qing Diao Mao Lin Yin Feng He Bin Li Xue Qiao Zhang Shandong Provincial Key Laboratory of UHV Transmission Technology and Equipment School of Electrical Engineering Shandong University Jinan Power-supply Company State Grid Shandong Electric Power Maintenance Company

ISBN: (纸本)9781467381086

Epoxy has become an integral insulating material for electric and electronic devices due to its excellent mechanical and electrical performance. As technology advances, increasing demands on the reliable operation under various operating and environmental conditions are made on materials and components. Based on the viewpoint of material modification, the properties of composite materials can be changed by the nano-particles. Whether the tracking resistance of epoxy nanocomposites can be improved under the combined environments needs better understanding for the reliable application. This paper describes the effects of atmospheric pressure on tracking failure of epoxy/SiO2 nanocomposites. The nano-SiO2 particles were mixed into pure epoxy to obtain the epoxy/SiO2 nanocomposites with the weight ratios of 1, 3, 5, 7 wt%, respectively. The effects of the concentration of SiO2 and atmospheric pressure on the time to tracking failure was discussed. Obtained results indicate that with the concentration from 0 to 3 wt%, the time to tracking failure shows the increasing tendency and the erosion depth shows the decreasing tendency. But they show the opposite varying tendency with the concentration from 3 to 7 wt%. Additionally, with decreasing the atmospheric pressure, the time to tracking failure increased. Therefore, the experimental results suggest that the tracking resistance of epoxy can be improved by nano-SiO2 particles and atmospheric pressure.

关键词： Epoxy SiO2 Composite Tracking failure Atmospheric pressure

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An improved risk assessment considering spinning reserve of power system with wind farm integration

An improved risk assessment considering spinning reserve of ...

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IEEE Region 10 International Conference TENCON

作者： Yuan Zeng Baozhu Zhou Wenfeng Zhu Chao Qin Xin Zhang Yuanyuan Li Zhenda Hu Zhangsui Lin Key Laboratory of Smart Grid of Ministry of Education Tianjin University Tianjin China China Electric Power Research Institute Beiiing China State Grid Fuiian Electric Power Co. Ltd. Economic and Technology Institute Fuzhou China

ISBN: (纸本)9781479986422

The massive integration of wind power brings more challenges to the safe operation of power system. In this paper, risk assessment methods of power system with wind power integration are studied by using DSR (dynamic security region) and risk assessment theory. The basic construction method of DSR boundary is introduced. The risk index calculation and comprehensive analysis method of wind power integration system are proposed based on DSR, which can give quantitative indicators of the system day-ahead scheduling plan and present the serious fault elements as well as vulnerable nodes of the system. A way to calculate the up and down spinning reserve capacity added to generator bus is discussed. Test results on the New England 10-genrator 39-bus system is presented and proves the effectiveness of this approach.

关键词： Wind power generation Spinning Generators Security

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transmission Network Expansion Planning Considering Uncertainties in Loads and Renewable Energy Resources

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CSEE Journal of power and Energy Systems 2015年第1期1卷 78-85页

作者： Jinyu Wen Xingning Han Jiaming Li Yan Chen Haiqiong Yi Chang Lu State Key Laboratory of Advanced Electromagnetic Engineering and Technology School of Electrical and Electronic EngineeringHuazhong University of Science and TechnologyWuhan430074China China South Power Grid International Co. LTDGuangzhou510080China State Power Economic Research Institute Beijing102209China

This paper proposes a novel method for transmission network expansion planning(TNEP)that take into account uncertainties in loads and renewable energy *** goal of TNEP is to minimize the expansion cost of candidate lines without any load curtailment.A robust linear optimization algorithm is adopted to minimize the load curtailment with uncertainties considered under feasible expansion ***,the optimal planning scheme obtained through an iterative process would be to serve loads and provide a sufficient margin for renewable energy *** this paper,two uncertainty budget parameters are introduced in the optimization process to limit the considered variation ranges for both the load and the renewable *** results obtained from two test systems indicate that the uncertainty budget parameters used to describe uncertainties are essential to arrive at a compromise for the robustness and optimality,and hence,offer a range of preferences to power system planners and decision makers.

关键词： Expansion planning renewable generation robust linear optimization transmission network uncertainty

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Distribution network load distribution strategy considering the economy of parallel transformers

Distribution network load distribution strategy considering ...

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Electrical Insulation Conference and Electrical Manufacturing & Coil Winding Conference

作者： Yanguang Huang Yanan Cai Youyuan Wang Hang Liu Central Testing and Researches Institute Guangzhou Power Supply Bureau Guangdong Power Grid Corporation Guangzhou China State Key Laboratory of Power Transmission Equipment & System Security and New Technology School of Electrical Engineering Chongqing University Chongqing China

ISBN: (纸本)9781479973552

The distribution transformer plays a key role in distribution network. It undertakes the task of the voltage transformation, energy distribution. But a lot of loss of the transformer in operation has affected the economy of the distribution network. Therefore in order to save energy, it is essential to consider the transformer economical operation mode during distribution network load distribution. Combining with the comprehensive power loss curve and critical load of transformer in parallel, the interval of economic operation of transformers in different operation modes is deduced in this paper. Then the unavailability of transformers in different operation mode is calculated. The distribution network load distribution model is proposed which takes distribution network reliability, the economy of parallel transformers and load balancing as the object function. The topological structure, load capacity and operating limits are given as the restriction conditions. Using optimization algorithm to analyze the model, the appropriate transformer operation mode and the load distribution scheme can be determined. What's more, a simple double power distribution network is used to show the steps of the distribution network load distribution considering the transformer economic operation mode. It makes clear that the model can determine the transformer operation mode and the load distribution strategy. The optimization results contribute to improving the distribution network reliability and economy.

关键词： Reliability Economics Load modeling

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Design and experimental results of a DC induction heater prototype for aluminum billets

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IEEE Transactions on Applied Superconductivity 2014年第3期24卷 1-4页

作者： Yang, J. Gao, H. Wang, Y.W. Xu, D.Q. Hong, Z. Jin, Z. Li, Z.Y. Key Laboratory of Control of Power Transmission and Conversion Ministry of Education State Energy Smart Grid R and D Center Shanghai Jiao Tong University Shanghai200240 China

The advantages of dc induction heating in high efficiency and good heating quality have been proved and studied worldwide in past decades. In this paper, a laboratory-scale dc induction heater with iron yoke for aluminum billets is designed and tested in detail. The billet to be heated is placed in the air gap of the yoke and is driven by a motor. The magnetic field in the gap is built up by copper windings with direct currents. The whole heating processes under different conditions are observed. Various surface temperature distributions have been achieved by changing several heating parameters including heating time, rotating speed, and dc magnetic field. Numerical analysis for calculating the heating process is also carried out in a commercial finite-element software. Results show that all the heating parameters will affect the final heating effects. Also, the numerical results agree well with the experimental results. © 2013 IEEE.

关键词： Finite element method

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Research on the measurement of space charge based on sound impulse

Research on the measurement of space charge based on sound i...

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International Conference on Properties and Applications of Properties and Applications of Dielectric Materials

作者： Kang-Lin Liu Rui-Jin Liao Hong-Bo Liu Xing-Rong Liao State Key Laboratory of Power Transmission Equipment & System Security and New Technology Chongqing University Chongqing P. R. China State Grid Chongqing Electric Power Co. Maintenance Branch Company Chongqing P. R. China

ISBN: (纸本)9781479989041

The space charge is one of important reasons affecting corona discharge, which is closely related to corona discharge mechanism, initiation and maintenance condition. How to acquire the distribution of space charge is always a puzzle which has not been settled. A space charge measurement method is proposed in this paper. Sound pulse makes the vibration of space charge, which results in the generation of electric field signal. Finite difference method is used to gain the relation between the space charge density and sound pressure. A set of contactless measuring systems are developed which can be used for real time measuring of the space charge distribution on a multi-needle-to-plate geometry. The system consists of an arbitrary custom-made sound generator and an electric field antenna.. Through finite difference method, space charge density can be obtained. The results gained by sound impulse method are compared with the result calculated by corona current method. Good agreements verify the validity of the proposed method.

关键词： Space charge Electric fields Corona Acoustics Finite element analysis Signal processing algorithms Discharges (electric)

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