检索结果-南通市图书馆

Analysis on carbon emission reduction intensity of fuel cell vehicles from a life-cycle perspective

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers in Energy 2024年第1期18卷 16-27页

作者： Ziyuan TENG Chao TAN Peiyuan LIU Minfang HAN Fuel Cell and Energy Storage Center Department of Energy and Power EngineeringState Key Laboratory of Control and Simulation of Power Systems and Generation EquipmentTsinghua UniversityBeijing 100084China

The hydrogen fuel cell vehicle is rapidly developing in China for carbon reduction and *** paper evaluated the life-cycle cost and carbon emission of hydrogen energy via lots of field surveys,including hydrogen production and packing in chlor-alkali plants,transport by tube trailers,storage and refueling in hydrogen refueling stations(HRSs),and application for use in two different *** also conducted a comparative study for battery electric vehicles(BEVs)and internal combustion engine vehicles(ICEVs).The result indicates that hydrogen fuel cell vehicle(FCV)has the best environmental performance but the highest energy ***,a sufficient hydrogen supply can significantly reduce the carbon intensity and FCV energy cost of the current *** carbon emission for FCV application has the potential to decrease by 73.1%in City A and 43.8%in City *** only takes 11.0%–20.1%of the BEV emission and 8.2%–9.8%of the ICEV *** cost of FCV driving can be reduced by 39.1%in City *** improvement can be obtained with an economical and“greener”hydrogen production pathway.

关键词： hydrogen energy life-cycle assessment(LCA) fuel cell vehicle carbon emission energy cost

Energy Planning of Beijing Towards Low-carbon,Clean and Efficient Development in 2035

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

CSEE Journal of power and Energy systems 2024年第3期10卷 913-928页

作者： Chengzhou Li Ningling Wang Xiaohu Shen Yumeng Zhang Zhiping Yang Xiaofeng Tong François Maréchal Ligang Wang Yongping Yang Institute of Energy power Innovation North China Electric Power UniversityBeijing 102206China School of Energy Power and Mechanical Engineering and National Research Center for Thermal Power Engineering and TechnologyNorth China Electric Power UniversityBeijing 102206China Industrial Process and Energy systems Engineering Swiss Federal Institute of Technology in LausanneSionSwitzerland

Energy transition towards clean,efficient energy supply has been a common sense of the government and public in ***,lacking reasonable planning will lead to undisciplined development,resource waste,and excessive *** this context,this paper investigates potential pathways of Beijing energy transition towards a high-level low-carbon,clean and efficient energy system in 2035 with an extended energysocpe ***,based on available data,future energy demands are predicted by a newly proposed hybrid forecasting method,which combines the traditional regression model,grey model,and support vector machine model with an entropy-based weighted ***,the superstructure-based optimization model is employed to investigate the system configuration and operation strategy of the future Beijing energy ***,the uncertainty impact of electricity price,natural gas price,hydrogen price,and the capital expenditures of electrolyzer and steam methane reforming for hydrogen applications are *** forecasting results show that all walks of life will witness a continuously increasing energy demand in multiple sectors of Beijing towards *** planning results suggest that the imported electricity and natural gas will dominate the energy supply of Beijing in 2035 with a contribution of 86%of the energy resources consumption of 384 ***,the energy system presents a high end-use electrification level of 65%and high penetration of efficient technologies,which supply 119 TWh via combined heat and power,26 TWh via heat pump and 95 TWh via district heating *** energy use of various sectors of energy resources,technologies and end-use are closely *** will have an increased penetration in the private mobility sector,but the locally generated hydrogen is mainly from steam methane reforming technology.

关键词： Energy transition energy planning carbonneutral demand forecasting energyscope

Detection of Nonlinear Behavior Induced by Hard Limiting in Voltage Source Converters in Wind Farms Based on Higher-order Spectral Analysis

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Modern power systems and Clean Energy 2024年第2期12卷 630-645页

作者： Zetian Zheng Shaowei Huang Qiangsheng Bu Chen Shen Jun Yan State Key Laboratory of power systems Department of Electrical EngineeringTsinghua UniversityBeijing 100084China State Grid Jiangsu Electric power Co. Ltd.Research InstituteNanjingChina

In recent years, sub-synchronous oscillation accidents caused by wind power integration have received extensive attention. The recorded constant-amplitude waveforms can be induced by either linear or nonlinear oscillation mechanisms. Hence, the nonlinear behavior needs to be distinguished prior to choosing the analysis method. Since the 1960s, the higher-order statistics(HOS) theory has become a powerful tool for the detection of nonlinear behavior(DNB) in production quality control wherein it has mainly been applied to mechanical condition monitoring and fault diagnosis. This study focuses on the hard limiters of the voltage source converter(VSC) control systems in the wind farms and attempts to detect the nonlinear behavior caused by bi-or uni-lateral saturation hard limiting using the HOS analysis. First, the conventional describing function is extended to obtain the detailed frequency domain information on the bi-and uni-lateral saturation hard limiting. Furthermore, the bi-and tri-spectra are introduced as the HOS, which are extended into bi-and tri-coherence spectra to eliminate the effects of the linear parts on the harmonic characteristics of hard limiting in the VSC control system, respectively. The effectiveness of the HOS in the DNB and the classification of the hard-limiting types is proven, and its detailed derivation and estimation procedure is presented. Finally, the quadratic and cubic phase coupling in the signals is illustrated, and the performance of the proposed method is evaluated and discussed.

关键词： Bi-coherence spectrum detection of nonlinear behavior hard limiting higher-order statistics tri-coherence spectrum voltage source converter wind farms.

Velocity transformation for compressible wall-bounded turbulence——An approach through the mixing length hypothesis

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2024年第9期67卷 108-125页

作者： Xuke Zhu Yubin Song Xiaoshuo Yang Zhenhua Xia State Key Laboratory of Fluid power and Mechatronic systems and Department of Engineering Mechanics Zhejiang UniversityHangzhou 310027China

In an endeavor to establish a connection between the mean velocity profile in compressible wall-bounded turbulence and its incompressible analogue,a refined version of the Trettel and Larsson's(TL)transformation is systematically derived and rigorously assessed across diverse flow *** the recently proposed intrinsic compressibility effects and modeling the multi-layer structure of mixing lengths,the proposed transformation demonstrates exceptional performance in collapsing 57canonical flow cases,including cooled channel and pipe flows,channel flows with pseudo heat sources,as well as adiabatic and diabatic boundary layer ***,the transformation seamlessly extends to low Reynolds number cooled channel and pipe flows,achieving a level of accuracy unparalleled by other transformations in the current state-of-the-art.

关键词： mixing length hypothesis compressible wall-bounded turbulence velocity transformation law of the wall

Energy Management of Price-maker Community Energy Storage by Stochastic Dynamic Programming

在线全文

学校读者我要写书评

暂无评论

CSEE Journal of power and Energy systems 2024年第2期10卷 492-503页

作者： Lirong Deng Xuan Zhang Tianshu Yang Hongbin Sun Yang Fu Qinglai Guo Shmuel S.Oren Department of Electrical Engineering Shanghai University of Electric PowerShanghai 200000China Tsinghua-Berkeley Shenzhen Institute Tsinghua UniversityShenzhen 518055China Department of Industrial Engineering and Operations Research University of California BerkeleyBerkeleyCAUSA Risk Analytics and Optimization Chair EPFLSwitzerlandand also with Power Systems LaboratoryETH Zurich8092 ZurichSwitzerland State Key Laboratory of power systems Department of Electrical EngineeringTsinghua UniversityBeijing 100084China

In this paper,we propose an analytical stochastic dynamic programming(SDP)algorithm to address the optimal management problem of price-maker community energy *** a price-maker,energy storage smooths price differences,thus decreasing energy arbitrage ***,this price-smoothing effect can result in significant external welfare changes by reduc-ing consumer costs and producer revenues,which is not negligible for the community with energy storage *** such,we formulate community storage management as an SDP that aims to maximize both energy arbitrage and community *** incorporate market interaction into the SDP format,we propose a framework that derives partial but sufficient market information to approximate impact of storage operations on market *** we present an analytical SDP algorithm that does not require state *** from computational efficiency,another advantage of the analytical algorithm is to guide energy storage to charge/discharge by directly comparing its current marginal value with expected future marginal *** studies indicate community-owned energy storage that maximizes both arbitrage and welfare value gains more benefits than storage that maximizes only *** proposed algorithm ensures optimality and largely reduces the computational complexity of the standard *** Terms-Analytical stochastic dynamic programming,energy management,energy storage,price-maker,social welfare.

关键词： Analytical stochastic dynamic programming energy management energy storage price-maker social welfare

Observer-Based Adaptive Robust Precision Motion Control of a Multi-Joint Hydraulic Manipulator

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

IEEE/CAA Journal of Automatica Sinica 2024年第5期11卷 1213-1226页

作者： Zheng Chen Shizhao Zhou Chong Shen Litong Lyu Junhui Zhang Bin Yao State Key Laboratory of Fluid power and Mechatronic systems Zhejiang UniversityHangzhou 310027 Ocean College Zhejiang UniversityZhoushan 316021China School of Mechanical Engineering Shijiazhuang Tiedao UniversityShijiazhuang 050000 State Key Laboratory of Fluid power and Mechatronic systems Zhejiang UniversityHangzhou 310027China School of Mechanical Engineering Purdue UniversityWest LafayetteIN 47907 USA

Hydraulic manipulators are usually applied in heavy-load and harsh operation ***,when faced with a complex operation,the traditional proportional-integral-derivative(PID)control may not meet requirements for high control ***-based full-state-feedback control is an effective alternative,but the states of a hydraulic manipulator are not always available and reliable in practical applications,particularly the joint angular velocity *** that it is not suitable to obtain the velocity signal directly from differentiating of position measurement,the low-pass filtering is commonly used,but it will definitely restrict the closed-loop bandwidth of the whole *** avoid this problem and realize better control performance,this paper proposes a novel observerbased adaptive robust controller(obARC)for a multi-joint hydraulic manipulator subjected to both parametric uncertainties and the lack of accurate velocity ***,a nonlinear adaptive observer is first designed to handle the lack of velocity measurement with the consideration of parametric ***,the adaptive robust control is developed to compensate for the dynamic uncertainties,and the close-loop system robust stability is theoretically proved under the observation and control ***,comparative experiments are carried out to show that the designed controller can achieve a performance improvement over the traditional methods,specifically yielding better control accuracy owing to the closed-loop bandwidth breakthrough,which is limited by low-pass filtering in fullstate-feedback control.

关键词： handle Observer filtering

An Adaptive Data-driven Method Based on Fuzzy Logic for Determining power System Voltage Status

在线全文

学校读者我要写书评

暂无评论

Journal of Modern power systems and Clean Energy 2024年第3期12卷 707-718页

作者： Sirwan Shazdeh Hêmin Golpîra Hassan Bevrani the SMGRC University of KurdistanSanandajIran power systems Modeling&Simulation Lab Department of Electrical EngineeringUniversity of KurdistanKurdistanSanandaj 66177-15175Iran

This paper proposes an adaptive method based on fuzzy logic that utilizes data from phasor measurement units(PMUs) to assess and classify generating-side voltage trajectories. The voltage variable and its associated derivatives are used as the input variables of a fuzzy-logic block. In addition, the voltage trajectory is compared with the pre-selected pilot-bus voltage to make a reliable decision about the voltage operational state. Different types of short-term voltage dynamics are considered in the proposed method. The fuzzy membership functions are determined using a systematic method that considers the current situation of the voltage trajectory. Finally, the voltage status is categorized into four classes to determine appropriate remedial actions. The proposed method is validated on a IEEE 73-bus power system in a MATLAB environment.

关键词： Fuzzy logic fault-induced delayed voltage recovery phasor measurement unit(PMU) short-term voltage stability situational awareness voltage classification

Numerical modeling and experimental investigation of a two-phase sink vortex and its fluid-solid vibration characteristics

在线全文

学校读者我要写书评

暂无评论

Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2024年第1期25卷 47-62页

作者： Zichao YIN Yesha NI Lin LI Tong WANG Jiafeng WU Zhe LI Dapeng TAN College of Mechanical Engineering Zhejiang University of TechnologyHangzhou310014China State Key Laboratory of Fluid power and Mechatronic systems Zhejiang UniversityHangzhou310058China

A sink vortex is a common physical phenomenon in continuous casting,chemical extraction,water conservancy,and other industrial processes,and often causes damage and loss in ***,the real-time monitoring of the sink vortex state is important for improving industrial production ***,its suction-extraction phenomenon and shock vibration characteristics in the course of its formation are complex mechanical dynamic factors for flow field state *** address this issue,we set up a multi-physics model using the level set method(LSM)for a free sink vortex to study the two-phase interaction ***,a fluid–solid coupling dynamic model was deduced to investigate the shock vibration characteristics and reveal the transition mechanism of the critical flow *** numerical results show that the coupling energy shock induces a pressure oscillation phenomenon,which appears to be a transient enhancement of vibration at the vortex penetration *** central part of the transient enhancement signal is a high-frequency *** on the dynamic coupling model,an experimental observation platform was established to verify the accuracy of the numerical *** water-model experiment results were accordant with the numerical *** above results provide a reference for fluid state recognition and active vortex control for industrial monitoring systems,such as those in aerospace pipe transport,hydropower generation,and microfluidic devices.

关键词： Free sink vortex Fluid-solid coupling Level set method(LSM) Multi-physics model Vibration characteristics

On the Security of Homomorphic Encryption Schemes with Restricted Decryption Oracles

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of systems Science & Complexity 2024年第5期37卷 2240-2261页

作者： MA Guangsheng LI Hongbo School of Mathematics and Physics North China Electric Power University Academy of Mathematics and systems Science Chinese Academy of Sciences University of Chinese Academy of Sciences

Fully homomorphic encryption（FHE） can be used for privacy-preserving aggregation of medical data. In this typical application, the security against passive attacks has been well studied by Li and Micciancio（2021）. In this paper, the authors further consider a “nearly passive” kind of attack, where the attacker may behave like a passive attacker in the view of the third-party *** capture the security against this hard-to-detect attack, the authors propose a new notion of IND-CPArDsecurity. The authors show that the standard LWE encryption and its related FHE schemes can not defend against IND-CPArDattack, even under a stricter rule limiting the content and number of queries made by the attacker. To make the application of FHE schemes more secure, the authors discuss some possible modifications that may serve as countermeasures to IND-CPArDattack.

关键词： Homomorphic encryption privacy secure cloud computing security