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Optimal Initialization and Starting Approach of Synchronous Condenser Integrated Power Grid

CSEE Journal of Power and Energy Systems 2024年第1期10卷 248-260页

作者： Puyu Wang Xing Liu Qingwen mou Tao Yuan Tianming Gu Hemin Yang Xiao-Ping Zhang Zhengrong Xiang Chunyi Guo School of Automation Nanjing University of Science and TechnologyNanjing 210094China NARI Group Corporation/State Grid EPRI and also with NARI Technology Co.Ltd. Nanjing 211106China School of Engineering University of BirminghamBirminghamB152TTUnited Kingdom State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources North China Electric Power UniversityBeijing 102206China

Synchronous condensers(SCs)are generally used at the receiving-end stations of ultra-high-voltage direct current(UHVDC)transmission systems due to their strong reactive power support and flexible regulation of reactive power according to the interconnected grids operating *** this paper,different starting control schemes of a SC integrated power grid are investigated providing four main contributions:1)The principle of reactive power support of the SC on the interconnected power grid is analytically studied,providing the establishment of mathematical models.2)Four different starting control schemes are developed for the initialization and SC integration,*** Scheme 1,a preset initial falling speed is directly utilized without initialization;in Scheme 2,a black start sequential control approach with a static frequency converter(SFC)is proposed;in Scheme 3,PI/PD/PID controllers are respectively applied for the excitation device at the speed-falling stage;in Scheme 4,a pre-insertion approach of an energy absorption component with R/L/rl is utilized to suppress the surges at the SC integration instant.3)The dynamic behaviors of four different starting schemes at specific operating stages are evaluated.4)The success rate of SC integration is analyzed to evaluate starting control *** of the SC interconnected system with four different starting control schemes is evaluated in the timedomain simulation environment PSCAD/EMTDC^(TM).The results prove the superiority of the proposed starting control approach in Scheme 4.

关键词： Black start dynamic behaviors excitation system pre-insertion of energy absorption components starting control schemes static frequency converter(SFC) success rate of integration synchronous condenser(SC)

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Robust Tracking Control for Self-balancing Mobile Robots Using Disturbance Observer

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IEEE/CAA Journal of Automatica Sinica 2017年第3期4卷 458-465页

作者： mou Chen College of Automation Engineering Nanjing University of Aeronautics and AstronauticsNanjing 210016China IEEE

In this paper,a robust tracking control scheme based on nonlinear disturbance observer is developed for the self-balancing mobile robot with external unknown disturbances.A desired velocity control law is firstly designed using the Lyapunov analysis method and the arctan *** improve the tracking control performance,a nonlinear disturbance observer is developed to estimate the unknown disturbance of the self-balancing mobile *** the output of the designed disturbance observer,the robust tracking control scheme is presented employing the sliding mode method for the selfbalancing mobile *** simulation results further demonstrate the effectiveness of the proposed robust tracking control scheme for the self-balancing mobile robot subject to external unknown disturbances.

关键词： Disturbance observer robust tracking control self-balancing mobile robot sliding mode control(SMC)

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基于拓扑分析的断层连通性定量评价及其油气地质意义——以四川盆地南部H井区为例

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天然气工业 2024年第3期44卷 97-107页

作者：裴仰文赵静茹郭伟牟毅城赵庆奇苗正硕深层油气全国重点实验室·中国石油大学(华东) 中国石油大学(华东)地球科学与技术学院中国石油勘探开发研究院

受多期次构造叠加改造作用影响,四川盆地南部地区(以下简称川南地区)深层页岩气储层中发育大量的中小尺度断层,定量评价断层网络结构和平面连通性对川南地区深层页岩气的勘探开发具有重要意义。为此,以该地区H井区为例,在三维地震精细刻... 详细信息

受多期次构造叠加改造作用影响,四川盆地南部地区(以下简称川南地区)深层页岩气储层中发育大量的中小尺度断层,定量评价断层网络结构和平面连通性对川南地区深层页岩气的勘探开发具有重要意义。为此,以该地区H井区为例,在三维地震精细刻画H井区深层页岩储层的中小尺度断层的基础上,基于拓扑学理论开展了该井区页岩储层断层网络拓扑结构分析和断层平面连通性评价,并结合已有页岩气井测试产气量进行关联性分析,定量评价了断层网络拓扑结构和平面连通性对页岩气富集的控制作用。研究结果表明:(1)断层节点和分支在空间上具有明显的差异性分布特征,且与构造走向具有较高的吻合度,呈北东—南西向条带状展布,并集中分布于3个狭长背斜带,3个向斜区分布较少。(2)不同构造部位的断层平面连通程度存在显著差异,背斜区平面连通性普遍较好,向斜区平面连通性较差;西部背斜带北段连通性最好,东部背斜带连通性次之,中部背斜带连通性最差;东部背斜带北段连通性较好,南段较差。(3)页岩气测试产量与断层平面连通性之间具有显著的相关性,随着断层平面连通性的增强,页岩气测试产量呈先升高后降低的趋势,反映连通性高值区和低值区均不利于页岩气富集。结论认为,该认识对中小断层连通性评价具有重要价值,也对深层页岩气的勘探开发有较高的实用价值。

关键词：四川盆地南部深层页岩气断层平面连通性拓扑结构分析定量评价油气地质意义

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Fractional-Order Control for a Novel Chaotic System Without Equilibrium

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IEEE/CAA Journal of Automatica Sinica 2019年第4期6卷 1000-1009页

作者： Shuyi Shao mou Chen the College of Automation Engineering Nanjing University of Aeronautics and AstronauticsNanjing 211106China IEEE

The control problem is discussed for a chaotic system without equilibrium in this *** the basis of the linear mathematical model of the two-wheeled self-balancing robot,a novel chaotic system which has no equilibrium is *** basic dynamical properties of this new system are studied via Lyapunov exponents and Poincar′e *** further demonstrate the physical realizability of the presented novel chaotic system,a chaotic circuit is *** using fractional-order operators,a controller is designed based on the state-feedback *** to the Gronwall inequality,Laplace transform and Mittag-Leffler function,a new control scheme is explored for the whole closed-loop *** the developed control scheme,the state variables of the closed-loop system are controlled to stabilize them to ***,the numerical simulation results of the chaotic system with equilibrium and without equilibrium illustrate the effectiveness of the proposed control scheme.

关键词： Chaotic system circuit implementation fractional-order stabilization

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Robust control for an unmanned helicopter with constrained flapping dynamics

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Chinese Journal of Aeronautics 2018年第11期31卷 2136-2148页

作者： Rong LI mou CHEN Qingxian WU College of Automation Engineering Nanjing University of Aeronautics and Astronautics

In this paper, a neural network based adaptive prescribed performance control scheme is proposed for the altitude and attitude tracking system of the unmanned helicopter in the presence of state and output constraints. For handling the state constraints, the barrier Lyapunov function and the saturation function are employed. And, the prescribed performance method is used to deal with the flapping angle constraints for the unmanned helicopter. It is proved that the proposed control approach can ensure that all the signals of the resulting closed-loop system are bounded, and the tracking errors are within the prescribed performance bounds for all time. The numerical simulation is given to illustrate the performance of the proposed scheme.

关键词： Altitude control Attitude control Barrier Lyapunov function Control constraint Prescribed performance Unmanned helicopter

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右佐匹克隆联合谷维素片治疗围绝经期女性焦虑性失眠的疗效及对相关神经递质的影响

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中国医院药学杂志 2024年第8期44卷 941-945页

作者：李洁牟娜宋永祯吕琛曹端华马红芳衡水市人民医院药学部河北衡水053000 衡水市人民医院检验科河北衡水053000 衡水市人民医院妇科河北衡水053000 衡水市人民医院肿瘤内科河北衡水053000 衡水市人民医院神经内科河北衡水053000

目的:分析右佐匹克隆辅助谷维素片治疗围绝经期女性焦虑性失眠的疗效及对神经递质的影响。方法:选择2020年1月至2023年1月期间衡水市人民医院就诊的202例围绝经妇女,分为对照组(右佐匹克隆片)和观察组(右佐匹克隆片联合谷维素片)。治疗... 详细信息

目的:分析右佐匹克隆辅助谷维素片治疗围绝经期女性焦虑性失眠的疗效及对神经递质的影响。方法:选择2020年1月至2023年1月期间衡水市人民医院就诊的202例围绝经妇女,分为对照组(右佐匹克隆片)和观察组(右佐匹克隆片联合谷维素片)。治疗前后,采用PSQI和HAMA评估患者睡眠质量和焦虑状况;检测患者血清5-羟色胺(5-HT)、γ-氨基丁酸(GABA)、去甲肾上腺素(ne)、多巴胺(DA)、脑源性神经营养因子(BDNF)、神经营养因子3(NT-3)、神经生长因子(NGF)、促卵泡生成素(FSH)、促黄体生成素(LH)和雌二醇(E2)水平;统计患者不良反应情况。结果:治疗后,观察组失眠患者PSQI和HAMA评分明显低于对照组(Pne、DA、FSH和LH水平明显低于对照组(P0.05)。结论:右佐匹克隆联合谷维素片可改善围绝经期女性焦虑性失眠症状。

关键词：右佐匹克隆谷维素片围绝经期焦虑性失眠疗效

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Rationally tailoring interface characteristics of ZnO/amorphous carbon/graphene for heat-conduction microwave absorbers

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Nano Research 2022年第10期15卷 8677-8687页

作者： Maofan Zhou Xuefei Xu Gengping Wan Pengpeng mou Shengjie Teng Guizhen Wang State Key Laboratory of Marine Resource Utilization in South China Sea Hainan UniversityHaikou 570228China

With the increasingly severe electromagnetic interference issue and the huge heat dissipation demand caused by the miniaturized and integrated electronic devices,exploring the heat-conduction microwave absorption(MA)materials is highly desired and remains a great ***,we reported the fabrication of ZnO/amorphous carbon(ZnO/AC)hybrid films covered on the surface of graphene(ZnO/AC/Graphene)to simultaneously apply as the MA and thermal management *** ZnO/AC coatings synthesized with the auxiliary of an atomic layer deposition(ALD)method are highly uniform and controllable,which can significantly improve the MA performance and thermal conduction properties of *** reflection loss(rl)of−55.4 dB and the effective absorption bandwidth of 5.3 GHz were achieved with thickness of 2.0 mm for ZnO/AC/Graphene at a low loading content(3 wt.%).The minimum rl of−57.9 dB can be obtained in the ZnO/AC/Graphene composites at a low frequency(7.8 GHz).Moreover,the absorption frequency can be regulated by changing the ZnO/AC which can be readily implemented by adjusting the ALD cycles of *** thermal conductivity of ZnO/AC/Graphene is up to 257.8 mW·m^(−1)·K^(−1),increased by 53.2%compared with natural *** enhancement mechanisms of microwave loss and heat conduction are systematically studied in *** work not only develops an excellent candidate,but also provides a novel strategy to design functional materials for heat-conduction MA application.

关键词： atomic layer deposition graphene microwave absorption heat conductivity

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Sedimentary Facies and Distribution of Reservoir Rocks from the Feixianguan Formation in the Daxian-Xuanhan Region, ne Sichuan

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Acta Geologica Sinica(English Edition) 2006年第1期80卷 137-151页

作者： MA Yongsheng mou Chuanlong GUO Xusheng YU Qian TAN Qinyin Southern Branch SINOPEC Kunming Yunnan 650200 Chengdu Institute of Geology and Mineral Resources Chengdu Sichuan 610082

The Lower Triassic Feixianguan Formation in the Daxian-Xuanhan region, northeastern Sicbuan is interpreted to be a carbonate platform intermediate between the West Hubei-East Cbongqing marine basin and Guangyuan-Wangcang marine basin. Outcrops, well logs and seismic data have disclosed that three sedimentary facies can be identified for the formation： open platform, platform exposed shoal and restricted platform facies. During the early stage of deposition of the Feixianguan Formation, there existed a sedimentary framework all the same as the Late Permian one： open platform in the west, and platform exposed shoal, restricted platform and open platform eastwards. The gradual increase of the shoal area permitted eastward migration of the shoal facies. During the deposition of the third member of the Feixianguan Formation, the study area was invaded by temporary transgressions. Till the deposition of the fourth member of the formation, the study area was prevailed over the unified restricted platform deposits, as indicated by the sedimentary model for the typical carbonate platform shoal deposits. The reservoir rocks in the Feixianguan Formation consist mostly of solution opening dolostone, and the rock types are assembled by oolitic dolostone, residual oolitic dolostone and sucrosic residual oolitic medium- to coarse-grained dolostone. The deep and shallow dual laterologs show relatively high resistivity, clear amplitude differences and time difference saltation of acoustic waves in some intervals. The seismic responses are indicated by low-frequency and highly variable amplitudes and chaotic reflection configurations. The reservoir rocks are characterized by high porosity-high permeability and medium porosity-medium permeability, showing a marked correlation between porosity and permeability. Solution openings are extremely developed in the reservoir rocks, including cast pores, intergranular solution openings, intercrystal pores, intercrystal solution openings, solu

关键词： Daxian-Xuanhan region Feixianguan Formation carbonate platform exposed shoal,physical property distribution of reservoir rocks

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Electrical arc contour cutting based on a compound arc breaking mechanism

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Advances in Manufacturing 2022年第4期10卷 583-595页

作者： Guo-Jian He Lin Gu Ying-mou Zhu Ji-Peng Chen Wan-Sheng Zhao K.P.Rajurkar State Key Laboratory of Mechanical System and Vibration School of Mechanical EngineeringShanghai Jiao Tong UniversityShanghai200240People’s Republic of China School of Mechanical and Electronic Engineering Nanjing Forestry UniversityNanjing210037People’s Republic of China Center for Nontraditional Manufacturing Research University of Nebraska-LincolnLincolnNEUSA

Electrical arc contour cutting(EACC)is a novel high-efficiency material cutting process that applies arc plasma to perform efficient and economical contour cutting of difficult-to-cut *** to conventional electrical arc machining(EAM),this process can remove the allowance of open structures and plates in bulk mode,rather than entirely in the form of *** with existing contour cutting methods,EACC possesses the advantages of high cutting efficiency and a deep cutting ***,a compound arc breaking mechanism(CABM),which integrates hydrodynamic force and mechanical motion,has been applied to control the discharge arc column in EACC,while also strengthening the debris expelling effect in the narrow discharge *** CABM implementation conditions were studied,based on arc column distortion images captured by a high-speed camera and simulation results of the flow field and debris distribution.A set of machining experiments was designed and conducted to optimize the performance of the proposed ***,a SiC_(p)/Al metal matrix composite(MMC)space station workpiece was machined to verify the feasibility and efficiency of this process.

关键词： Electrical arc contour cutting(EACC) Electrical arc machining(EAM) Compound arc breaking mechanism(CABM) SiC_(p)/Al metal matrix composite(MMC) High efficiency

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Wind Wave Characteristics and Engineering Environment of the South China Sea

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Journal of Ocean University of China 2014年第6期13卷 893-900页

作者： WANG Zhifeng ZHOU Liangming DONG Sheng WU Lunyu LI Zhanbin mou Lin WANG Aifang College of Engineering Ocean University of China College of Physical and Environmental Oceanography Ocean University of China The First Institute of Oceanography State Oceanic Administration National Marine Data and Information Service State Oceanic Administration Engineering Reconnaissance & Design Institute Ocean University of China

Wave simulation was conducted for the period 1976 to 2005 in the South China Sea （SCS） using the wave model, WAVEWATCH-III. Wave characteristics and engineering environment were studied in the region. The wind input data are from the objective reanalysis wind datasets, which assimilate meteorological data from several sources. Comparisons of significant wave heights between simulation and TOPEX/Poseidon altimeter and buoy data show a good agreement in general. By statistical analysis, the wave characteristics, such as significant wave heights, dominant wave directions, and their seasonal variations, were discussed. The largest significant wave heights are found in winter and the smallest in spring. The annual mean dominant wave direction is northeast （ne） along the southwest （SW）-ne axis, east northeast in the northwest （NW） part of SCS, and north northeast in the southeast （SE） part of SCS. The joint distributions of wave heights and wave periods （directions） were studied. The results show a single peak pattern for joint significant wave heights and periods, and a double peak pattern for joint significant wave heights and mean directions. Furthermore, the main wave extreme parameters and directional extreme values, particularly for the 100-year return period, were also investigated. The main extreme values of significant wave heights are larger in the northern part of SCS than in the south- ern part, with the maximum value occurring to the southeast of Hainan Island. The direction of large directional extreme Hs values is focus in E in the northem and middle sea areas of SCS, while the direction of those is focus in N in the southeast sea areas of SCS.

关键词： surface waves statistical characteristics joint distributions extreme parameters

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