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Power Flow Calculation for VSC-based AC/DC Hybrid Systems Based on Fast and Flexible Holomorphic Embedding

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Journal of Modern Power Systems and Clean Energy 2024年第5期12卷 1370-1382页

作者： Peichuan Tian Yexuan Jin Ning Xie chengmin wang Chunyi Huang Key Laboratory of Control of Power Transmission and Conversion(Ministry of Education) Shanghai Jiao Tong UniversityShanghai 200240China the State Grid Hangzhou Power Supply Company Hangzhou310009China

The power flow(PF)calculation for AC/DC hybrid systems based on voltage source converter(VSC)plays a crucial role in the operational analysis of the new energy *** fast and flexible holomorphic embedding(FFHE)PF method,with its non-iterative format founded on complex analysis theory,exhibits superior numerical performance compared with traditional iterative *** paper aims to extend the FFHE method to the PF problem in the VSC-based AC/DC hybrid *** form the AC/DC FFHE PF method,an AC/DC FFHE model with its solution scheme and a sequential AC/DC PF calculation framework are *** AC/DC FFHE model is established with a more flexible form to incorporate multiple control strategies of VSC while preserving the constructive and deterministic properties of original FFHE to reliably obtain operable AC/DC solutions from various initializations.A solution scheme for the proposed model is provided with specific recursive solution processes and accelerated Padé*** achieve the overall convergence of AC/DC PF,the AC/DC FFHE model is integrated into the sequential calculation framework with well-designed data exchange and control mode switching *** proposed method demonstrates significant efficiency improvements,especially in handling scenarios involving control mode switching and multiple *** numerical tests,the superiority of the proposed method is confirmed through comparisons of accuracy and efficiency with existing methods,as well as the impact analyses of different initializations.

关键词： AC/DC power flow holomorphic embedding numerical performance voltage source converter(VSC)

Risk-averse Market Clearing for Coupled Electricity, Natural Gas and District Heating System

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CSEE Journal of Power and Energy Systems 2019年第2期5卷 240-248页

作者： Haibing wang chengmin wang Muhammad Qasim Khan Gengwu Zhang Ning Xie Department of Electrical Engineering Shanghai Jiao Tong UniversityShanghai 200240China

Multiple energy carriers can be coupled as an Integrated Energy System (IES) through interconnection tech- nologies. Unexpected risks will be transferred with the growing coupling of energy systems, mainly stemming from the uncertain- ties in different energy sectors. It is imperative to coordinate the operation of different energy systems to improve energy efficiency and ensure energy security. With the close integration of different energy systems, it is necessary to couple these different energy markets to achieve the holistic energy supply economy. On the other hand, uncertainties in the energy systems will bring the financial risk for the operator of IES. A risk-averse stochastic market clearing model for the IES is proposed to study the operating strategy aiming at minimizing the operation cost. While the financial risk imposed by the wind power uncertainties is restricted to a predefined level. Simulations results are provided to verify that the proposed model can improve market efficiency and handle the trade-off between cost and risk.

关键词： CVaR integrated energy system market clearing power-to-gas stochastic programming

Determining the Planning Period of a Distribution Substation Based on Acceptable Errors

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CSEE Journal of Power and Energy Systems 2017年第3期3卷 296-301页

作者： Gengwu Zhang chengmin wang Lin Fu Haibing wang Department of Electrical Engineering Shanghai Jiao Tong UniversityShanghai 200240China State Power Economic Research Institute of Xinjiang Urumqi 830001China

The distribution substation planning is faced with numerous uncertainties so that the planning result can only be a“rough outline,”and the problem of determining the planning period *** the basis of the assessment of uncertainties in distribution planning,a specific approach to determine the planning period of a distribution substation based on acceptable errors is proposed,indicating that the load forecast error is the key factor to affect the planning *** order to provide a clearer understanding of this paper’s primary objective,the proposed approach is applied to determining the planning period of a power supply radius optimization(PSRO)model in distribution substation ***,an example is illustrated which validates the suggested approach of this paper.

关键词： Acceptable error distribution substation planning load forecast error planning period power supply radius optimization

Isolation and characterization of a Neisseria sp. from the captive wild goose (Anser anser)

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Integrative Zoology 2016年第2期11卷 128-133页

作者： chengmin wang Jing LUO Haijing wang Said AMER Hua DING Ying DONG Hongxuan HE National Research Center For Wildlife Born Diseases Key Laboratory of Animal Ecology and Conservation BiologyInstitute of ZoologyChinese Academy of SciencesBeijingChina Department of Zoology Faculty of ScienceKafr El Sheikh UniversityKafr El SheikhEgypt Department of Infectious Diseases Hangzhou Center for Disease Control and PreventionHangzhouChina Department of Medical Oncology the Second Affiliated HospitalCollege of MedicineZhejiang UniversityHangzhouChina

The present study investigated 15 dead cases of captive wild goslings(Anser anser),which were bred in a small poultry farm in Shandong Province,*** examined cases presented diverse clinical signs accompanied with neurological manifestations and fatal *** culture identified the gram-negative Neisseria *** the brain homogenate of most examined cases(10/15,66.7%).The isolated bacteria were identified based on morphologic characteristics,biochemical tests and 16S rDNA *** proved that 1 identical bacterial strain(BNO09-3)was isolated from the positive *** phylogeny based on the 16S rDNA gene sequences indicated that this isolate has a close relationship with various strains of genus Neisseria *** from liver and feces of *** is the first report of Neisseria *** fatality in captive wild geese in China.

关键词： 16S rDNA Anser anser China Neisseria sp.

Comparing Competition Equilibrium with Nash Equilibrium in Electric Power Market

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CSEE Journal of Power and Energy Systems 2018年第3期4卷 299-304页

作者： Haibing wang Jian Deng chengmin wang Weiqing Sun Ning Xie Department of Electrical Engineering Shanghai Jiaotong UniversityShanghai 200240China Department of Business Administration Jilin University of Finance&EconomicsChangchun 130117China Department of Electrical Engineering University of Shanghai for Science&TechnologyShanghai 200093China

The Nash equilibrium and competition equilibrium have been widely studied in the electric power market up to *** this paper,it is explained that the Nash equilibrium can be achieved by using marginal cost pricing and the com-petition equilibrium can be performed by using accounting cost pricing based on the model of the power market *** comparison between the Nash equilibrium and competition equilibrium indicates that surplus and unfair allocation of market benefits may be obtained by the Nash equilibrium,and the competition equilibrium realizes the optimization in economics with maximum market efficiency and fairness for market benefit allocations while the optimization in mathematics is achieved by the Nash *** is sameness between the Nash equilibrium and competition equilibrium at the point when the power network characteristics are *** case study is made on a IEEE 30-bus system,and the calculation results indicate that it is the key issue to perform the competition equilibrium by using accounting cost pricing.

关键词： Accounting cost pricing competition equilibrium marginal cost pricing market failure market surplus Nash equilibrium power market

Discovery and Significance of Malan Loess on the Piedmont Plain in Pinggu District, Beijing

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Acta Geologica Sinica(English Edition) 2014年第5期88卷 1565-1578页

作者： LU Lu ZHAO Yuanyi wang Xiaoliang ZHAO Xitao YANG Zhenjing wang chengmin BI Zhiwei LU Wenhui Institute of Mineral Resources Chinese Academy of Geological Sciences Beijing Institute of Geology Liaoning Institute of Geology and Mineral Resources Institute of Geology and Geophysics Chinese Academy of Sciences Institute of Hydrogeology and Environmental Geology Chinese Academy of Geological Sciences No.3 Geology and Mineral Exploration Institute of Gansu Provincial Bureau of Geology and Mineral

The platforms on both sides of the Malangou River （a lateral ditch of the Qingshui River that is a tributary of the Yongding River） where Malan Village in Zhaitang Town of Mentougou District of Beijing is located are the place of China＇s typical section of the Quaternary Malan loess. During the investigation in the eastern suburbs of Beijing City, the authors not only clarified 5 grades of terraces on the Pinggu piedmont plain, but also found a clayey silt section mixed with a small amount of alluvial-diluvial gravel layers at a height of 15-25 m above the river level near a Fishpond in Xinli Village of Nandule Town. Results of the study of grain size of the section document that the loess mostly is silty soil （0.05--0.005 mm）, and that the grain size probability cumulative curves of the section are dominated by single-peak, coarse-grained segment I and coarse-grained segment II types, reflecting that its depositional environment is similar to eolian phase. Identification results of heavy minerals from the section show that their contents account for 0.01%-0.11%, averaging 0.04%. There are 24 kinds of heavy minerals, most of which are stable heavy minerals, and the clay minerals mostly are illite, which is consistent with the Malan loess on the Loess Plateau. The chemical composition data reflect that the source area of the loess is relatively arid. The six grade classification of sporopollen in the section further shows the subdivision of the history of alternating warm and humid phases in this geological period. The thermoluminescence dating results range from 21.0 ka to 59.2 ka, convincingly demonstrating that the section indeed consists of Malan loess. The above studies provide a new basis for overall understanding of the distribution of the Malan loess at the northeast margin of the North China Plain and its environment change in the Late Pleistocene.

关键词： eolian loess Malan loess formation environment Pinggu

Molecular characterization of H1N1 influenza A viruses from human cases in North America

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Chinese Science Bulletin 2009年第13期54卷 2179-2192页

作者： WU Bin wang chengmin DONG GuoYing LUO Jing ZHAO BaoHua HE HongXuan National Research Center For Wildlife Born Diseases Key Laboratory of Animal Ecology and Conservation Biology Institute of Zoology Chinese Academy of Sciences Beijing 100101 China Graduate University of Chinese Academy of Sciences Beijing 100049 China College of Life Science Hebei Normal University Shijiazhuang 050016 China

Subtypes of H1N1 influenza virus can be found in humans in North America,while they are also asso-ciated with the infection of *** of the genotypes of viral strains in human popula-tions is important to understand the source and distribution of viral *** and protein sequences of 10 isolates of the 2009 outbreak ofinfluenza A(H1N1) virus in North America were obtained from GenBank *** characterize the genotypes of these viruses,phylogenetic trees of genes PB2,PB1,PA,HA,NP,NA,NS and M were constructed by Phylip3.67 program and N-Linked glycosylation sites of HA,NA,PB2,NS1 and M2 proteins were analyzed online by NetNGlyc1.0 *** analysis indicated that these isolates are virtually identical but may be recombinant viruses because their genomic fragments come from different *** isolates also contain a char-acteristic lowly pathogenic amino acid motif at their HA cleavage sites(IPSIQSR↓GL),and an E residue at position 627 of the PB2 protein which shows its high affinity to *** homologous model of M proteins showed that the viruses had obtained the ability of anti-amantadine due to the mutation at the drug-sensitive site,while sequence analysis of NA proteins indicated that the viruses are still suscep-tible to the neuraminidase inhibitor drug(*** and zanamivir) because no mutations have been *** results strongly suggested that the viruses responsible for the 2009 outbreaks ofinfluenza A(H1N1) virus have the ability to cross species barriers to infect human and mammalian animals based on molecular *** findings may further facilitate the therapy and prevention of possible transmission from North America to other countries.

关键词： A型流感病毒分子鉴定北美病例人类

Weak Fault Detection of Rotor Winding Inter-Turn Short Circuit in Excitation System Based on Residual Interval Observer

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Structural Durability & Health Monitoring 2023年第4期17卷 337-351页

作者： Gang Liu Xinqi Chen Lijuan Bao Linbo Xu Chaochao Dai Lei Yang chengmin wang Zhejiang Zheneng Jiahua Power Generation Co. Ltd.Hangzhou314201China Zhejiang Zheneng Technology Research Institute Co. Ltd.Hangzhou310000China Zhejiang Key Laboratory of High Efficiency Energy Saving and Pollutant Control Technology for Thermal Power GenerationHangzhou310000China Shanghai Jiaotong University Shanghai200240China

Aiming at the fact that the rotor winding inter-turn weak faults can hardly be detected due to the strong electromagnetic coupling effect in the excitation system,an interval observer based on current residual is ***,the mechanism of the inter-turn short circuit of the rotor winding in the excitation system is modeled under the premise of stable working conditions,and electromagnetic decoupling and system simplification are carried out through Park *** interval observer is designed based on the current residual in the two-phase coordinate system,and the sensitive and stable conditions of the observer is *** fault diagnosis process based on the interval observer is formulated,and the observer gain matrix is convexly optimized by linear matrix *** numerical simulation and experimental results show that the inter-turn short circuit weak fault is hardly detected directly through the current signal,but the fault is quickly and accurately diagnosed through the residual internal *** with the traditional fault diagnosis method based on excitation current,the diagnosis speed and accuracy are greatly improved,and the probability of misdiagnosis also *** method provides a theoretical basis for weak fault identification of excitation systems,and is of great significance for the operation and maintenance of excitation systems.

关键词： Excitation system interval observer rotor winding weak fault detection inter-turn shortcut

Resilience enhancement strategy using microgrids in distribution network

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Global Energy Interconnection 2018年第5期1卷 537-543页

作者： Jiaren wang Ning Xie Wenxian Wu Dong Han chengmin wang Binruo Zhu Shanghai Jiaotong University University of Shanghai for Science and Technology Electric Power Measurement Center SMEPC

We propose a restoration strategy using microgrids for restoring power supply to critical loads after an extreme event and thereby enhancing the resilience of the distribution power grid. The limited capacities of distributed generators(DGs) within the microgrids and those of intermittent energy sources such as wind and photovoltaic power are considered. An enhanced strategy model of the distribution network is established for maximizing the power supply to critical loads. Firstly, the importance of the load is quantified by using the analytic hierarchy process(AHP) and the model of the microgrid output is further improved. In the demand response mechanism, an interruptible load is used to suppress the fluctuation in the distributed power output. Secondly, piecewise linearization method is applied to address the power flow constraints. Then, the resilience enhancement model of the distribution network is transformed into a mixed integer quadratic programming problem. The CPLEX solver is adopted to solve the above problem on the MATLAB platform. Finally, the proposed method is verified by applying it to practical scenarios.

关键词： Resilience Distribution power grid Microgrid Load restoration Piecewise linear approximation