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IEEE/PES Transmission and Distribution Conference and Exhibition: Asia and Pacific

作者： Peng Li Qian Bai Baoli Zhao Yihan Yang Key Laboratory of Power System Protection and Dynamic Security Monitoring and Control under Ministry of Education North China Electric Power University Baoding Hebei China Baoding Baoling Transformer Company Limited Baoding Hebei China

power quality becomes an emphasis of related researches. Based on the detailed study on QCC (quality control center) of the FRIENDS first advanced by Japanese scholars, the functions of QCC are expanded and its basic types and structures are defined. Meanwhile, by detailed study, this paper introduces the multiple adjusting functions of UPQC (unified power quality conditioner) which is the chief part of QCC and presents its typical topological circuit. Moreover, H infin control technology is used to realize the synthesis tracking compensation of voltage and current for UPQC. Finally its validity has been testified successfully

关键词： power quality power supplies power system reliability Automatic control Energy management Quality management Communications technology Quality control power system management power generation economics

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A new protection algorithm for EHV transmission line based on singularity detection of fault transient voltage

A new protection algorithm for EHV transmission line based o...

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International power Engineering Conference (IPEC)

作者： Ming-yu Yang Wan-ye Yao Zeng-ping Wang Yan-jun Jiao Ju Zhang Key Laboratory of Power System Protection and Dynamic Security Monitoring Control under Ministry of Education North China Electric Power University Baoding Hebei China Automation Department of North China Electric Power University Baoding Hebei China

ISBN: (纸本)9810557027

A new non-unit voltage protection algorithm for extra high voltage (EHV) transmission lines is presented in this paper. The singularity of fault transient voltage signals in one terminal is utilized to discriminate clearly between internal and external faults. Lipschitz exponent (LE) is obtained from wavelet modulus maximum to detect singularity of signals. A typical 500 kV EHV transmission system has been simulated by ATP to evaluate the scheme. The simulation results show that this scheme is capable of providing correct responses under various system configurations and fault conditions

关键词： Transmission lines Fault detection power system transients Voltage power system protection power transmission lines Wavelet transforms Circuit faults Signal detection Frequency

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A new ultra high-speed protection scheme based on wavelet analysis

A new ultra high-speed protection scheme based on wavelet an...

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International power Engineering Conference (IPEC)

作者： Ming-yu Yang Wan-ye Yao Zeng-ping Wang Ju Zhang Yan-jun Jiao Key Laboratory of Power System Protection and Dynamic Security Monitoring and Control under Ministry of Education North China Electric Power University Baoding Hebei China Automation Department North China Electric Power University Baoding Hebei China

ISBN: (纸本)9810557027

A new ultra high-speed protection scheme is proposed in this paper. Using wavelet transform with multiresolution analysis, the current signals is decomposed into a series of detailed wavelet components. The spectral energies of the wavelet components are calculated and then employed to detect the faults. Characteristics of the proposed ultra high-speed protection algorithm are analyzed and results of simulation studies are given. The results show that the proposed algorithm is promising and easy to implement for computer relaying application

关键词： protection Wavelet analysis Wavelet transforms Multiresolution analysis Fault detection Algorithm design and analysis Computational modeling Analytical models Computer applications Protective relaying

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Residual voltage transformation method for short-circuit current calculation with matrix transformation

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Zhongguo Dianji Gongcheng Xuebao/Proceedings of the Chinese Society of Electrical Engineering 2005年第23期25卷 61-65页

作者： Jiang, Tong Bai, Xue-Feng Guo, Zhi-Zhong Lu, Ying Laboratory of Power System Protection and Dynamic Security Monitoring and Control North China Electric Power University Beijing 102206 China School of Electrical Engineering and Automation Harbin Institute of Technology Harbin 150001 China Dept. of Electrical Engineering Tsinghua University Beijing 100084 China

Unbalanced element brings a big problem to fault analysis of symmetrical components method. According with fault analysis of phase components, a residual voltage transformation method for short-circuit current calculation is presented with matrix translation in the place of classical sequence networks connection, which is suitable for both phase coordinates and symmetrical components coordinates. Calculation formulas are proposed with matrices calculation to deal with unsymmetrical faults and parameter matrices for various faults are listed. Analysis of simultaneous faults with unbalanced parameter element is done without calculation qualities increased. Simple examples have shown that the method is practical and suitable for programming.

关键词： Short circuit currents

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power Quality Disturbance Detection Based on Mathematical Morphology and Fractal Technique

Power Quality Disturbance Detection Based on Mathematical Mo...

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IEEE/PES Transmission and Distribution Conference and Exhibition: Asia and Pacific

作者： Gengyin Li Ming Zhou Yan Luo Yixin Ni Key Laboratory of Power System Protection and Dynamic Security Monitoring and Control under Ministry of Education North China Electric Power University Baoding Hebei China Department of Electrical and Electronic Engineering University of Hong Kong Hong Kong China

Based on mathematical morphology and grille fractal, a novel approach on power quality disturbance detection and location is presented in this paper. At first a parallel composite morphological filter with multiple-structure elements is designed to filter the random noise and impulse noise in power quality disturbance signals. Then to the filtered curves, an easy implementation criterion for singularity detection based on the change regularity of grille fractal is proposed to locate the start and end time that disturbance occurs. The voltage sag, swell, harmonic and their combined disturbances are used to verify the validity of the proposed filter-location approach. Numerical results show that the proposed approach is valid and effective

关键词： power quality Morphology Fractals power harmonic filters Signal sampling Signal analysis Shape Educational programs Noise shaping Voltage fluctuations

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Risk Management on Long-term Electricity Purchase Allocation in China power Markets

Risk Management on Long-term Electricity Purchase Allocation...

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International Conference on power Electronics and Drive Systems (PEDS)

作者： Ming Zhou Gengyin Li Yanli Nie Yixin Ni Key Laboratory of Power System Protection and Dynamic Security Monitoring and Control under Ministry ofEducation North China Electric Power University Baoding Hebei China Department of Electrical and Electronic Engineering University of Hong Kong Hong Kong China

This paper presents an integrated framework for the optimal management of electricity purchase allocation and risk for load service entities (LSEs). To the practice of China power Markets, we propose the framework of power portfolio of combined physical forward contract and spot market. The framework suggests that the forward contracts should have different prices on-peak and off-peak in accord with sale prices distinguish on-peak and off-peak. The optimal purchase problem is described by the utility maximum integrated the rate of return and risk tolerance level, and risk is evaluated by Value at Risk (VaR). The analytical solution is also conducted. The numerical results are reasonable with higher rate of return and better risk hedging compared with the corresponding results from the existing portfolio selection approach. The presented framework gives one possible and effective method for the optimal power portfolio and risk management in incomplete power markets.

关键词： Risk management power markets Portfolios Forward contracts Electricity supply industry Pricing Marketing and sales Energy consumption power generation Scheduling

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Integrating Radial Basis Function Neural Network with Fuzzy control for Load Forecasting in power System

Integrating Radial Basis Function Neural Network with Fuzzy ...

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IEEE/PES Transmission and Distribution Conference and Exhibition: Asia and Pacific

作者： Siqing Sheng Cong Wang Laboratory of Power System Protection and Dynamic Security Monitoring and Control under Ministry of Education North China Electric Power University Baoding Hebei China School of Electrical Engineering North China Electric Power University Baoding Hebei China

Short-term load forecasting of power system is not only the basis of scheduling of generating sets, but also the basis of working out the transaction schedule in electricity market. This paper proposes a short-term load forecasting method based on combination of radial basis function (RBF) neural network and fuzzy control, uses on-line self-modify factor fuzzy control to eliminate forecast error on the basis of RBF neural network forecasting. The practical examples show that the accuracy of short-term load forecasting and training speed can be improved and gains the very satisfactory results by the proposed method

关键词： Radial basis function networks Fuzzy control Load forecasting power system control power systems Neural networks Economic forecasting power generation Electricity supply industry Error correction

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Research on Remote Meter Automatic Reading Based on Computer Vision

Research on Remote Meter Automatic Reading Based on Computer...

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IEEE/PES Transmission and Distribution Conference and Exhibition: Asia and Pacific

作者： Shutao Zhao Baoshu Li Jinsha Yuan Guiyan Cui Key Laboratory of Power System Protection and Dynamic Security Monitoring and Control under Ministry of Education North China Electric Power University Baoding Hebei China Electrical Communication Department North China Electric Power University Baoding Hebei China North China Electric Power University Baoding Hebei China

A novel method is put forward, which the power meter can be read based on compute vision, and the architecture of remote meter auto reading system is designed. Different with the normal automatic meter reading system that must obtain the value from digital communication interface, the new method recognizes the meter reading utilizing the computer vision technique, it is a kind of non-contact measurement. In the meter automatic reading, the computer vision discrimination, incorporate human's ability of visual and apprehensive models. Not only the digital display power meter can be read, but also the direct-reading instrument can be fetched. In this paper, the scheme of remote automatic reading is introduced, the local meter reading information of distributed substation can be transmitted to center using computer network and then the pretreatment, segmentation and pattern matching, are detailed description in the meter image recognition process. Via energy meter automatic recognition experiment, the results based computer vision is accurate enough to monitor the remote substation running parameters

关键词： Computer vision Meter reading Substations Computer architecture Automatic meter reading Digital communication power system modeling Computer displays Instruments Computer networks

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Numerical prediction of EMI on the secondary DC cable in cable tunnel due to a direct lightning strike in substation

Numerical prediction of EMI on the secondary DC cable in cab...

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作者： Qi, Lei Cui, Xiang Key Laboratory of Power System Protection and Dynamic Security Monitoring and Control Ministry of Education North China Electric Power University Hebei 071003 China

Electromagnetic interference (EMI) on secondary dc cable in cable tunnel due to a direct lightning strike in substation threatens the safe operation of electronic equipment and system connected to the cable. In order to reduce EMI, the cable shield is generally connected to the grounding grid at both ends. Ground potential difference between two grounding points of the cable shield can be high due to high impedance of the grounding grid at high frequencies. In this paper, we present a hybrid method to analyze this complex system. As a result, both the current flowing in the cable shield and the transverse voltage between the cable core and shield are calculated. Compared with the measured results, the proposed method is demonstrated to be correct and effective. © 2006 IEEE.

关键词： Signal interference

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Subcell FDTD analysis of shielding effectiveness of a thin-walled enclosure with an aperture

Subcell FDTD analysis of shielding effectiveness of a thin-w...

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作者： Jiao, Chaoqun Li, Lin Cui, Xiang Li, Huiqi Key Laboratory of Power System Protection and Dynamic Security Monitoring and Control Ministry of Education North China Electric Power University Hebei 071003 China

An improved subcell model is presented for including thin material sheets method in the finite-difference time-domain (FDTD) method. This improved subcell can be used to simulate a thin magnetic (μs ≠ μo) sheet. Then, the improved subcell model is applied to the analysis of the shielding effectiveness (SE) of the electromagnetic wave propagating through a thin infinite material sheet, which is verified by comparison with the analytical results. Updated equations for components of the field on special spatial grids which are on edges and corners of the enclosure are presented, and the subcell model is used for the analysis of a thin-walled enclosure with an aperture. The FDTD results are in very good agreement with the test results. © 2006 IEEE.

关键词： Thin walled structures

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