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Aggregation Modeling of System Frequency Response Under Inertia control of Grid-following Direct-drive Wind Turbine

Dianli Xitong Zidonghua/Automation of Electric Power Systems 2025年第10期49卷 39-48页

作者： Jiang, Chao Yang, Dongfeng Guo, Shujia Liu, Xiaojun Zhou, Shuyu Cao, Zhichong Key Laboratory of Modern Power System Simulation and Control & Renewable Energy Technology Ministry of Education Northeast Electric Power University Jilin132012 China School of Automation and Electrical Engineering Zhejiang University of Science and Technology Hangzhou310023 China State Grid Jilin Electric Power Research Institute Changchun130000 China

The inertia control of grid-following direct-drive wind turbines significantly influences the system frequency response pattern afrer disturbances. However, current research has not clearly identified the dominant response link of direct-drive wind turbines in frequency regulation, while the modeling is too complicated to be suitable for frequency characteristic analysis. Therefore, the linearized models under inertia control are derived for two typical types of direct-drive wind turbines according to the aerodynamic equations, generator models, power control link, and control circuit structure. The fast physical process of current control-boost circuit/stator voltage dynamic loop is clearly understood and reasonably ignored. It is revealed that the two types of direct-drive wind turbines have a common frequency response mechanism which can be described as the cascade effect of the speed regulator-wind rotor motion equation. Furthermore, combined with the frequency response model of synchronous unit, the aggregation model of system frequency response under the inertia control of grid-following direct-drive wind turbines is constructed, and the aggregation model is reduced to a second-order model by the balance truncation method for analytical calculation of frequency extremes. The accuracy and applicability of the aggregation model and its reduced-order model are verified by MATLAB/Simulink simulation, and the influence of control parameters and system states on frequency dynamic characteristics and stability margin is analyzed. © 2025 Automation of Electric Power Systems Press. All rights reserved.

关键词： Electric power system control

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Quantitative relationship between hippocampal injury and mechanical load and body weight in closed head injury of male rats using quadratic orthogonal regression

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Scientific Reports 2025年第1期15卷 1-13页

作者： Wang, Peng Song, Xuewei Wang, Qiushi Qiu, Jinlong Zhu, Xiyan Yu, Tianming Xiang, Hongyi Zhao, Hui State Key Laboratory of Automotive Simulation and Control College of Automotive Engineering Jilin University Jilin Changchun China Institute for Traffic Medicine Daping Hospital Army Medical University Chongqing China

Memory dysfunction, a common symptom following closed head impact injuries, suggests deficits in hippocampal function. This defect is thought to be related to impact strength and individual animal weight. In this study, head impact experiments were performed on male Sprague Dawley rats to establish a quantitative relationship between impact strength, body weight and hippocampal injury. A two-factor, three-level experimental design was established using the L₉(3⁴) orthogonal table, with impact strength and body weight as the variables. According to the protocol, rats were injured using a BIM-IV animal impact machine, and the effects of impact strength and body weight factors on hippocampal injury were evaluated by the results of Morris water maze and hematoxylin–eosin staining of the hippocampus at 24 h post-injury. Using the percentage of cell loss in the hippocampus as an indicator, quadratic regression models were established to describe the effects of impact strength and body weight on cell loss in the CA1, CA3, and DG regions of the hippocampus. The results revealed a quadratic, non-linear relationship between impact strength, body weight and the percentage of cell loss in these regions. Specifically, increasing impact strength resulted in a higher proportion of cell loss, whereas increasing body weight was associated with a reduction in cell loss. Consistent with these pathological findings, higher impact strength prolonged the time required for rats to locate the hidden platform in the Morris water maze, while higher body weight shortened the platform-finding time under the same impact strength. The quadratic orthogonal regression equations for hippocampal injury as a function of mechanical load and body weight provide valuable insights for predicting hippocampal damage and understanding its underlying mechanisms. © The Author(s) 2025.

关键词： Closed head injury Hippocampal injury Quadratic orthogonal regression

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Hydrothermal aging alleviates hydrocarbon poisoning effects on high-silica Cu-SSZ-16 catalysts for NH 3 -SCR

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Journal of Environmental Sciences 2025年 158卷 13-23页

作者： Huan Zhou Jianqi Liu Yan Zhang Shichao Han Jinpeng Du Wenpo Shan Fujian Key Laboratory of Atmospheric Ozone Pollution Prevention Institute of Urban Environment Chinese Academy of Sciences Xiamen 361021 China Zhejiang Key Laboratory of Pollution Control for Port-Petrochemical Industry Ningbo Urban Environment Observation and Research Station Institute of Urban Environment Chinese Academy of Sciences Ningbo 315800 China Shanghai Advanced Research Institute Chinese Academy of Sciences Shanghai 201210 China State Key Joint Laboratory of Environment Simulation and Pollution Control Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing 100085 China

Hydrocarbons (HCs) exert toxic effects on the activity of Cu-based zeolite catalysts for NH 3 -SCR on diesel vehicles. This study investigated the hydrocarbon resistance of both fresh and hydrothermally aged high-silica Cu-SSZ-16 catalysts. It was found that low-temperature activity of Cu-SSZ-16 catalyst decreased after C 3 H 6 poisoning, which was mainly due to the blockage of pore channels and the coverage of Cu active sites as well as acid sites by the formation of carbon deposits. Additionally, [Cu(OH)] + -Z was proposed to be more easily affected by C 3 H 6 poisoning than Cu 2+ -2Z. Hydrothermally aged Cu-SSZ-16 presented better C 3 H 6 resistance than the fresh catalyst since less carbon deposits were accumulated and [Cu(OH)] + -Z species were partially transformed to more-stable Cu 2+ -2Z in the aged sample. This was probably because of the reduction of acid sites and the formation of CuO x , which enhanced the oxidation of C 3 H 6 , thereby inhibiting the formation of carbon deposits. In addition, the coverage of the active Cu species also influenced the adsorption and oxidation of NO, causing a decrease in low-temperature activity. Thus, the low-temperature activity could be fully recovered by hydrothermal treatment at 500 °C due to the removal of carbon deposits and recovery of Cu active sites as well as acid sites. In summary, high-silica Cu-SSZ-16, with high resistance to HCs and excellent hydrothermal stability, is a competitive candidate as a catalyst for the NH 3 -SCR reaction in practical application.

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Adaptive Adjustment Method for Grid-forming Energy Storage Parameters Based on Buffer Functions and Damping Switching

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Dianli Xitong Zidonghua/Automation of Electric Power Systems 2025年第10期49卷 77-86页

作者： Cui, Yang Ma, Boyu Dai, Hanyang Ma, Xin Zhao, Yuting Key Laboratory of Modern Power System Simulation and Control & Renewable Energy Technology Ministry of Education Northeast Electric Power University Jilin132012 China China Electric Power Research Institute Beijing100192 China Electric Power Research Institute of State Grid Ningxia Electric Power Ltd. Co. Yinchuan750002 China

In the development tendency of high penetration of renewable energy and power electronic devices in new power systems, the grid-forming control technology for renewable energy integration mitigates the system stability issues caused by insufficient inertia and damping. However, it also reduces the dynamic regulation performance of the system. This paper proposes an adaptive adjustment method for grid-forming energy storage parameters based on buffer functions and steady-state/transient-state damping switching, to improve the dynamic regulation performance of the system. Firstly, the buffer functions are used in inertia adjustment to enhance the regulation smoothness of the system. Secondly, a steady-state/transient-state damping switching link is introduced in the damping adjustment to reduce the steady-state error of active power output during the frequency reduction process. Thirdly, the fuzzy control is employed to introduce correction terms for inertia and damping, and the stability of the proposed method is analyzed. Finally, simulations validate the effectiveness of the proposed method in enhancing small-signal stability and power response dynamic performance of the system. © 2025 Automation of Electric Power Systems Press. All rights reserved.

关键词： Electric power transmission networks

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Antibiotic resistance occurrence and ecological impact in landfill leachate: A review on compound effect of antibiotics and non-antibiotics

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Emerging Contaminants 2025年第3期11卷

作者： Xu, Yongtao Li, Dan Yuan, Ying Fang, Fei Xi, Beidou Tan, Wenbing State Key Laboratory of Environmental Criteria and Risk Assessment and State Environmental Protection Key Laboratory of Simulation and Control of Groundwater Pollution Chinese Research Academy of Environmental Sciences Beijing 100012 China Technical Centre for Soil Agriculture and Rural Ecology and Environment Ministry of Ecology and Environment Beijing 100012 China

Landfilling remains one of the primary methods for managing municipal solid waste (MSW), processing approximately 350 million tons of waste annually. Among the various components of landfill waste, pharmaceuticals and personal care products (PPCPs), including both antibiotics and non-antibiotic compounds, pose significant environmental challenges. Landfill leachate is a highly complex medium, consisting of diverse contaminants such as non-antibiotic pharmaceuticals (average concentration ∼1.74 μg/L), antibiotics (average concentration ∼527 ng/L), heavy metals, dissolved organic matter, and micro/nano-plastics (concentration range 0.64–2.16 mg/L). This unique mixture can alter the native microbial community structure, profoundly impacting antibiotic resistance, potentially disrupting soil and groundwater ecosystems, and threatening ecological balance. Existing research has extensively investigated the composition, physicochemical properties, environmental behavior, and microbial community structure of landfill leachate, leading to significant advancements in the field. However, due to the complexity and large volume of landfill leachate, current risk assessment approaches predominantly rely on conventional pollutant indicators, and most treatment strategies are designed for general contaminants. There is a lack of systematic descriptions that integrate pollutants with their direct impacts on microbial communities. This review focuses on the current pollution status, spatiotemporal trends, interactions, and migration risks of antibiotics and non-antibiotic pollutants in landfill leachate. In particular, we explore the in situ emergence of antibiotic resistance in landfill leachate (rather than the horizontal transfer of antibiotic resistance genes) and examine the influence of various leachate components on antibiotic resistance. By emphasizing the importance of understanding the combined effects of antibiotics and non-antibiotic pollutants in landfill environments, t

关键词： Antibiotic resistance Antibiotics and non-antibiotic substances Composition effect Landfill leachate

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Waste photovoltaic wafers-derived SiC-based photocatalysts for pharmaceutical wastewater purification: S-scheme, waste utilization, and life cycle assessment

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Resources, Conservation and Recycling 2025年 220卷

作者： Teng, Chengyao Huang, Qing Cheng, Yunyan Zhang, Zhongyi Zhang, Li Zhu, Jianming Xu, Lijun Song, Qingbin Bian, Zhenfeng Li, Jinhui Yuan, Wenyi School of Resources and Environmental Engineering Shanghai Polytechnic University No. 2360 Jinhai Road Shanghai201209 China Macao Environmental Research Institute Macau University of Science and Technology Macao999078 China MOE Key Laboratory of Resource Chemistry and Shanghai Key Laboratory of Rare Earth Functional Materials Shanghai Normal University Shanghai200234 China State Key Joint Laboratory of Environment Simulation and Pollution Control School of Environment Tsinghua University Beijing100084 China

Waste photovoltaic (PV) wafers recovered from modules by physical crushing contain high levels of impurities and are unsuitable for reuse. This research demonstrates the successful regeneration of SiC (r-SiC) nanowires photocatalysts from these discarded PV wafers. The r-SiC exhibits enhanced photoactivity and reduces environmental emissions compared to market SiC, as evidenced by a life cycle assessment. By synthesizing ZnxCd1-xS/r-SiC (ZxC1-xSS) photocatalysts featuring a S-scheme heterojunction and internal electric field (IEF)-driven •OH production capability, we have not only repurposed waste but also achieved an unprecedented leap in photocatalytic efficiency. The resulting 20 %Zn0.2Cd0.8S/r-SiC (20Z0.2C0.8SS) photocatalyst exhibited a remarkable 96.67 % cefaclor (CEC) degradation efficiency under visible light within 30 min—outperforming r-SiC by 126-fold and Zn0.2Cd0.8S by 44-fold, and enabling efficient pharmaceutical wastewater degradation. This pioneering research not only turns waste into a valuable resource but also establishes a new benchmark in photocatalytic technology, providing profound insights into the mechanisms underpinning ZxC1-xSS photocatalysts. © 2025

关键词： Photocatalysts

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Identification of Maximum Road Friction Coefficient and Optimal Slip Ratio Based on Road Type Recognition

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Chinese Journal of Mechanical Engineering 2014年第5期27卷 1018-1026页

作者： GUAN Hsin WANG Bo LU Pingping XU Liang State Key Laboratory of Automotive Simulation and Control Jilin University

The identification of maximum road friction coefficient and optimal slip ratio is crucial to vehicle dynamics and ***,it is always not easy to identify the maximum road friction coefficient with high robustness and good adaptability to various vehicle operating *** existing investigations on robust identification of maximum road friction coefficient are *** this paper,an identification approach based on road type recognition is proposed for the robust identification of maximum road friction coefficient and optimal slip *** instantaneous road friction coefficient is estimated through the recursive least square with a forgetting factor method based on the single wheel model,and the estimated road friction coefficient and slip ratio are grouped in a set of samples in a small time interval before the current time,which are updated with time *** current road type is recognized by comparing the samples of the estimated road friction coefficient with the standard road friction coefficient of each typical road,and the minimum statistical error is used as the recognition principle to improve identification *** the road type is recognized,the maximum road friction coefficient and optimal slip ratio are *** numerical simulation tests are conducted on two typical road friction conditions（single-friction and joint-friction）by using CarSim *** test results show that there is little identification error between the identified maximum road friction coefficient and the pre-set value in *** proposed identification method has good robustness performance to external disturbances and good adaptability to various vehicle operating conditions and road variations,and the identification results can be used for the adjustment of vehicle active safety control strategies.

关键词： maximum road friction coefficient optimal slip ratio road type recognition recursive least square

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Semi-empirical equivalent circuit model and evaluation of energy losses for alkaline electrolysis stack in dynamic operations

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International Journal of Hydrogen Energy 2025年 138卷 859-873页

作者： Sha, LianDong Lin, Jin Qi, Ruomei Li, Qinghui Li, Wenying Lin, Ruixiao Gao, Danhui Li, Hang Li, Xiaolong Yang, Chenxi Song, Yonghua State Key Laboratory of Control and Simulation of Power Systems and Generation Equipment Department of Electrical Engineering Tsinghua University Beijing 100084 China Tsinghua-Sichuan Energy Internet Research Institute Chengdu 610213 China School of Chemistry and Chemical Engineering Southwest Petroleum University Chengdu 610213 China School of Nuclear Science and Engineering North China Electric Power University Beijing 100084 China State Key Laboratory of Internet of Things for Smart City University of Macau 999078 Macao

In various applications of alkaline water electrolysis (AWE) for hydrogen production, the efficiency of AWE stacks is a critical concern. Emerging applications involve significant dynamic operations, necessitating the evaluation of their impact on stack efficiency. However, a quantitative understanding of the power losses within AWE stacks under dynamic conditions remains limited. A significant research challenge exists in the development of models for AWE stacks that can accommodate dynamic operating conditions, and there is a need for a systematic approach to classify and quantify energy losses within the stack. This paper presents a quantitative assessment method for losses in AWE stacks based on a semi-empirical equivalent circuit model (SECM). The losses within the AWE stack are categorized into four types based on their generation mechanisms: overpotential losses, shunt current losses, non-Faradaic losses, and electrochemical cycling losses (cycling losses for short). Using experimental data from 5 MW and 10 kW AWE stacks, the parameters of the SECM observer are identified through a stepwise data-driven approach, resulting in a mean square error of less than 46.4 mV for 5 MW stack and 80.9 mV for 10 kW stack. The constructed SECM observer is employed to simulate the proportion of various losses under different dynamic operating conditions. This paper focuses on the efficiency and loss behaviors of AWE stacks under multi-stack switching strategies. Case studies demonstrate that the current range, ramp rate, regulation period, and duty cycle significantly influence the four types of losses. Based on the SECM observer, recommended parameters for multi-stack switching are provided. This work contributes to accurate assessment of AWE stack efficiency under dynamic operations and provides a methodology for designing AWE stack operating strategies. © 2025 Hydrogen Energy Publications LLC

关键词： Alkaline water electrolysis stack Dynamic operation Efficiency Electrochemical cycling losses Equivalent circuit model Multi-stack switching strategies

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One Step Positive Approach for Sheet Metal Forming simulation Based on Quasi-conjugate-gradient Method

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Chinese Journal of Mechanical Engineering 2013年第4期26卷 730-736页

作者： NA Jingxin CHEN Wei State Key Laboratory of Automotive Simulation and Control Jilin University

In one step inverse finite element approach, an initial blank shape is normally predicted from the final deformed shape. The final deformed shape needs to be trimmed into a final part after stamping, the trimmed area, therefore, needs to be compensated manually before using one step inverse approach, which causes low efficiency and in consistency with the real situation. To solve this problem, one step positive approach is proposed to simulate the sheet metal stamping process. Firstly the spatial initial solution of one step positive method is preliminarily obtained by using the mapping relationship and area coordinates, then based on the deformation theory the iterative solving is carried out in three-dimensional coordinate system by using quasi-conjugate-gradient method. During iterative process the contact judgment method is introduced to ensure that the nodes on the spatial initial solution are not separated from die surface. The predicted results of sheet metal forming process that include the shape and thickness of the stamped part can be obtained after the iterative solving process. The validity of the proposed approach is verified by comparing the predicted results obtained through the proposed approach with those obtained through the module of one step inverse approach in Autoform and the real stamped part. In one step positive method, the stamped shape of regular sheet can be calculated fast and effectively. During the iterative solution, the quasi-conjugate-gradient method is proposed to take the place of solving system of equations, and it can improve the stability and precision of the algorithm.

关键词： positive approach deformation theory quasi-conjugate-gradient method

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Design and Optimization for the Occupant Restraint System of Vehicle Based on a Single Freedom Model

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Chinese Journal of Mechanical Engineering 2013年第3期26卷 492-497页

作者： ZHANG Junyuan MA Yue CHEN Chao ZHANG Yan State Key Laboratory of Automobile Simulation and Control Jilin University

Throughout the vehicle crash event, the interactions between vehicle, occupant, restraint system (VOR) are complicated and highly non-linear. CAE and physical tests are the most widely used in vehicle passive safety development, but they can only be done with the detailed 3D model or physical samples. Often some design errors and imperfections are difficult to correct at that time, and a large amount of time will be needed. A restraint system concept design approach which based on single-degree-of-freedom occupant-vehicle model (SDOF) is proposed in this paper. The interactions between the restraint system parameters and the occupant responses in a crash are studied from the view of mechanics and energy. The discrete input and the iterative algorithm method are applied to the SDOF model to get the occupant responses quickly for arbitrary excitations (impact pulse) by MATLAB. By studying the relationships between the ridedown efficiency, the restraint stiffness, and the occupant response, the design principle of the restraint stiffness aiming to reduce occupant injury level during conceptual design is represented. Higher ridedown efficiency means more occupant energy absorbed by the vehicle, but the research result shows that higher ridedown efficiency does not mean lower occupant injury level. A proper restraint system design principle depends on two aspects. On one hand,the restraint system should lead to as high ridedown efficiency as possible, and at the same time, the restraint system should maximize use of the survival space to reduce the occupant deceleration level. As an example, an optimization of a passenger vehicle restraint system is designed by the concept design method above, and the final results are validated by MADYMO, which is the most widely used software in restraint system design, and the sled test. Consequently, a guideline and method for the occupant restraint system concept design is established in this paper.

关键词： vehicle crash occupant restraint system concept design single-degree-of-freedom occupant-vehicle model

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