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Assessment Framework of Green Intelligent Transformation of Small Hydropower in China

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Energy Engineering 2022年第2期119卷 681-697页

作者： Jun Shi Zhejiang electric power Industry corporation Hangzhou310006China

With the comprehensive promoted construction of the establishment of green small hydropower,the defects of existing small hydropower station are gradually emerging,and it is necessary to implement green intelligent transformation to promote the construction of energy internet in *** study focuses on constructing a green intelligent planning and transforming assessment framework,and assists management department to filtrate the small hydropower stations which can be transformed ***,power station economy,ecological environment,technical safety management and social benefits are involved in the assessment index ***,multi-expert judgment aggregation based on fuzzed comparison scale is put forward to calculate the index value,and evidence synthesis is used to comprehensively assess the feasibility of green and intelligent planning and transformation for several small hydropower *** simulation case analysis shows the constructed assessment framework can reflect the actual situation of objectives properly and would provide decision-making basis for green and intelligent planning and transformation of small hydropower stations.

关键词： Small hydropower green intelligent transformation multi-expert judgment evidence synthesis

Fault component integrated impedance-based pilot protection scheme for EHV/UHV transmission line with thyristor controlled series capacitor(TCSC) and controllable shunt reactor(CSR)

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Science China(Technological Sciences) 2013年第2期56卷 342-350页

作者： HE ShiEn SUONAN JaLe KANG XiaoNing JIAO ZaiBin Department of electrical Engineering Xi'an Jiaotong University Wind power Technology Center Gansu Electric Power Corporation

This paper analyzes the fundamental frequency impedance presents a novel transmission line pilot protection scheme characteristic of a thyristor controlled series capacitor （TCSC） and based on fault component integrated impedance （FCII） calculated for a transmission line with TCSC and controllable shunt reactor （CSR）. The FCII is defined as the ratio of the sum of the fault component voltage phasors of a transmission line with TCSC and CSR to the sum of the fault component current phasors where all the phasors are determined at both line＇s terminals. It can be used to distinguish internal faults occurring on the line from external ones. If the fault is an external one the FCII reflects the line＇s capacitive impedance and has large value. If the fault is an internal one on the line the FCII reflects the impedance of the equivalent system and the line and is relatively small. The new pilot protection scheme can be easily set and has the fault phase selection ability and also it is not affected by the capacitive current and the fault transition resistance. It is not sensitive to compensation level and dynamics of TCSC and CSR. The effectiveness of the new scheme is validated against data obtained in ATP simulations and Northwest China 750 kV Project.

关键词： EHV/UHV transmission line pilot protection fault component integrated impedance (FCII) thyristor controlled seriescapacitor (TCSC) controllable shunt reactor (CSR)

Excitation and Detection of Shear Horizontal Waves with Electromagnetic Acoustic Transducers for Nondestructive Testing of Plates

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Chinese Journal of Mechanical Engineering 2014年第2期27卷 428-436页

作者： MA Qingzeng JIAO Jingpin HU Ping ZHONG Xi WU Bin HE Cunfu electric power Research Institute of Guangdong power Grid corporation College of Mechanical Engineering and Applied Electronics Technology Beijing University of Technology

The fundamental shear horizontal（SH0） wave has several unique features that are attractive for long-range nondestructive testing（NDT）. By a careful design of the geometric configuration, electromagnetic acoustic transducers（EMATs） have the capability to generate a wide range of guided wave modes, such as Lamb waves and shear-horizontal（SH） waves in plates. However, the performance of EMATs is influenced by their parameters. To evaluate the performance of periodic permanent magnet（PPM） EMATs, a distributed-line-source model is developed to calculate the angular acoustic field cross-section in the far-field. Numerical analysis is conducted to investigate the performance of such EMATs with different geometric parameters, such as period and number of magnet arrays, and inner and outer coil widths. Such parameters have a great influence on the directivity of the generated SH0 waves that arises mainly in the amplitude and width of both main and side lobes. According to the numerical analysis, these parameters are optimized to obtain better directivity. Optimized PPM EMATs are designed and used for NDT of strip plates. Experimental results show that the lateral boundary of the strip plate has no perceivable influence on SHO-wave propagation, thus validating their used in NDT. The proposed model predicts the radiation pattern ofPPM EMATs, and can be used for their parameter optimization.

关键词： electromagnetic acoustic transducers shear-horizontal waves strip plate nondestructive testing

Atmospheric Corrosion of Copper Exposed in a Simulated Coastal-Industrial Atmosphere

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Journal of Materials Science & Technology 2017年第6期33卷 587-595页

作者： Chen Pan Wangyan Lv Zhenyao Wang Wei Su Chuan Wang Shinian Liu Environmental Corrosion Center Institute of Metal Research Chinese Academy of Sciences electric power Research Institute Guangdong Power Grid Corporation

The corrosion behavior of copper exposed in a simulated coastal-industrial atmosphere has been investigated using weight loss measurement, scanning electron microscopy, X-ray diffraction, potentiodynamic polarization and in-situ electrochemical impedance spectroscopy（EIS） with micro-distance *** results show that corrosion kinetics follows the empirical equation D = Atn. The main corrosion products are composed of Cu_2O, Cu_2Cl（OH）_3 and Cu_4Cl_2（OH）_6. A two-layer structure comprising a loose outer layer and a compact inner layer forms the corrosion products during corrosion process. SO_2 has been found to promote the formation of Cu_4Cl_2（OH）_6.

关键词： Copper Atmospheric corrosion SEM EIS

Dynamic Comprehensive Assessment of power Development Based on Provincial Data

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CSEE Journal of power and Energy Systems 2020年第3期6卷 672-680页

作者： Wei Hu Qiuting Guo Yifan Zhou Yi Kang Huanshuai Bing Dan Bao State Key Lab of power Systems the Department of Electrical EngineeringTsinghua UniversityBeijing 100084China Central Southern China electric power Design Institute China Power Engineering Consulting Group CorporationWuhan 430071China Northeast branch State Grid Corporation of ChinaShenyang 110180China

Dynamic comprehensive assessment of regional power industry development levels is of paramount importance for understanding the development characteristics and potential of the local power industry.A tri-level evaluation index system is established,describing five aspects of the local power industry development level,specifically,the coordination degree between the power industry and economy/energy,power generation,power consumption,power supply and development potential.A combination of information entropy and the analytic hierarchy process(AHP)is used to establish a static evaluation model,and a blend of subjective opinions and objective data information is then *** aggregating the static evaluation model for each time period based on a time-ordered weighting vector calculated using time-ordered information entropy,a dynamic comprehensive evaluation model of power industry development level is *** considering provincial data from China recorded during 2007 to 2016 as the sample set,through synchronic and diachronic comparisons of the evaluation results,the differences,characteristics and potential of local power industry development in China are explored.

关键词： Analytic hierarchy process development level of power electric industry dynamic comprehensive assessment information entropy

An improved strategy for out-of-step oscillation separation devices based on apparent impedance angle applied to a series compensated line

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Protection and Control of Modern power Systems 2022年第1期7卷 316-323页

作者： Haibo Xu Yupeng Cai Xiaolei Qu Zhiwei Dong NARI Group corporation/State Grid electric power Research Institute Nanjing 210003China electric power Research Institute of State Grid Liaoning electric power Co. LtdShenyang 110006China

Out-of-step oscillation separation devices based on apparent impedance angle trajectory are widely used in the power grid in China,and their reliability is of great *** this paper,the influence mechanism of series compensation on apparent impedance angle trajectory is *** reveals that series compensation capacitors reduce the equivalent impedance angle and consequently the apparent impedance angle cannot pass through all four zones,resulting in the risk of failure for the separation devices.A revised method of apparent impedance angle based on compensation principle is discussed,and then an improved out-of-step oscillation detection criterion is *** view of the fact that the apparent impedance angle at the moment of maximum current is equal to the equivalent impedance angle during an oscillation process,a practical algorithm based on the compensated apparent impedance angle is *** tests are conducted to verify the effectiveness of the new criterion,considering transmission lines with a high series compensation level.

关键词： Out-of-step oscillation separation Series compensated line Apparent impedance angle Compensated impedance angle

Application of Excitation Function to the Prediction of RI Level Caused by Corona Discharge

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Plasma Science and Technology 2012年第12期14卷 1091-1096页

作者： ZHU Lingyu JI Shengchang HUI Sisi GUO Jun LI Yansong FU Chenzhao The State Key Laboratory of electrical Insulation and power Equipment Xi'an Jiaotong University Xi'an 710049 China Shanxi electric power corporation Taiyuan 030001 China electric power Research Institute SMEPC Shanghai 200437 China

Radio interference （RI）, as an aftereffect of corona discharge, is an important research topic in the field of electromagnetic compatibility, where excitation function is applied broadly to the prediction of RI level. This paper presents the theory of excitation function method used in the RI level prediction. Then, some practical problems related to this method are discussed. The propagation procedure of corona current is solved by the phase-modal transformation, and the impedance matrix of multi transmission lines is calculated by a double logarithmic approximate model of Carson＇s Ground-Return impedance. At the same time, in order to calculate the RI level when total line corona is assumed, an analytical formula is deduced for integral operation. Based on the above solutions, an algorithm is presented and applied to the prediction of RI level of a practical overhead transmission line. Comparison of prediction and measurement results indicates that the algorithm proposed in this paper is effective and feasible.

关键词： radio interference excitation function modal propagation Ground-Return impedance

Cyber-physical Collaborative Restoration Strategy for power Transmission System Considering maintenance Scheduling

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CSEE Journal of power and Energy Systems 2024年第3期10卷 1331-1341页

作者： Baozhong Ti Chuanyun Zhang Jingfei Liu Zhaoyuan Wu Ziyang Huang North China branch of State Grid corporation of China Beijing 100053China State Grid Beijing electric power Company Beijing 100031China State Key Laboratory of Alternate electrical power System with Renewable Energy Sources School of Electrical and Electronic EngineeringNorth China Electric Power UniversityBeijing 102206China IEEE CSEE

In order to improve the ability of power transmission system to cope with compound faults on the communication side and power side,a cyber-physical collaborative restoration strategy is ***,according to the information system’s role in fault diagnosis,remote control of equipment maintenance and automatic output adjustment of generator restoration,a cyber-physical coupling model is *** this basis,a collaborative restoration model of power transmission system is established by studying interactions among maintenance schedule paths,information system operation,and power system *** on power flow linearization and the large M-ε method,the above model is transformed into a mixed integer linear programming model,whose computational burden is reduced further by the clustering *** to the parameters of IEEE39 New England system,the geographic wiring diagram of the cyber-physical system is *** results show the proposed restoration strategy can consider the support function of the information system and space-time coordination of equipment maintenance at both sides comprehensively to speed up load recovery progress.

关键词： Clustering method collaborative restoration cyber-physical power system maintenance scheduling power transmission system restoration

Three-phase fault direction identification method for outgoing transmission line of DFIG-based wind farms

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Journal of Modern power Systems and Clean Energy 2019年第5期7卷 1155-1164页

作者： Zhanfeng FAN Guobing SONG Xiaoning KANG Jisi TANG Xiaobo WANG Xi’an Jiaotong University Xi’anChina State Grid Beijing electric power Company BeijingChina State Grid Shanxi maintenance Company TaiyuanChina

Doubly-fed induction generator(DFIG)-based wind farm has the characteristic of transient fault with low voltage ride through(LVRT)capability.A new three-phase fault direction identification method for the outgoing transmission line of the wind farm is *** ability of the new directional relay to differentiate between a three-phase fault in one direction or the other is obtained by using the increment of phase angle difference between the memory voltage signal and the fault current signal within a certain time,and using the amplitude variation of the fault *** can be inferred that the fault current is supplied by the wind farm whether the phase angle differs or the current amplitude varies *** fault locations at the outgoing transmission line have been simulated by PSCAD/EMTDC to evaluate the reliability and sensitivity of the proposed *** show that the new directional relay is of faster response when a three-phase fault occurs at the outgoing transmission line of a DFIG-based wind farm.

关键词： Wind farm Doubly-fed induction generator(DFIG) Directional relay Outgoing transmission line