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Journal of Iron and Steel Research(International) 2024年第3期31卷 622-633页

作者： Pu Wang Liang Chen Qun-wei Tang Wei-tao Li Shao-xiang Li Jia-quan Zhang School of Metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing 100083China Weifang Special Steel Group Co..Ltd. Weifang 262400ShandongChina School of Materials Science and Engineering Tsinghua UniversityBeijing 100084China

The propagation form of internal cracks induced by continuous casting soft reduction and the control strategy for enhancing the internal quality of 45 steel through industrial trials and a three-dimensional flow-heat transfer-solidification coupling model were investigated.The results showed that the internal cracks induced by soft reduction exhibited a characteristic of being"coarse in the middle and fine at both ends",and displayed an elliptical arc distribution on the loose side of the strand cross section.The cracks originated within the brittle temperature range and propagated inward to the liquid impenetrable temperature and outward to the zero ductility temperature or below.The control strategy for enhancing the internal quality of the 45 steel strand through soft reduction is to adjust the casting speed or the reduction zone appropriately,ensuring that the central solid fraction of the reduction zone falls within the range of 0.33-0.99.At this point,a reasonable reduction amount is allocated to eliminate the center shrinkage cavities and center segregation,even if it results in minor reduction-induced cracks.

关键词： Continuous casting Soft reduction Crack propagation Internal quality control strategy

control strategy of shortcut nitrification

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Journal of Environmental Sciences 2006年第1期18卷 58-61页

作者： QAISAR Mahmood Department of Environmental Engineering Zhejiang University Hangzhou 310029 China.

Shortcut nitrification for ammonium-rich wastewater is energy-saving and cost-effective procedure that has become one of the hotspots in the field of biological denitrogenation. An orthogonal experiment was performed to study the combined effects of operational parameters on the performance of internal-loop airlift bioreactor for shortcut nitrification. The optimum operational parameters for the shortcut nitrification were fotmd as temperature 35 ℃, pH 8.0, dissolved oxygen concentration 1.0 mg/L, ammonium concentration 4 mmol/L and HRT 16 h, which have different influence on the performance of shortcut nitrification reactor. The pH, temperature and dissolved oxygen concentration have significant bearing on the process. The results showed that the shortcut nitrification reactor could be successfully started up within 42 d, and the reactor performance is steady with minimum NO2-/NOx- of 85.2%, maximum 93.4% and average value of 91.4% in effluent. Based on the analysis of experimental data, a new control strategy named “priority ＋ combination” for shortcut nitrification was suggested. Through this strategy, the startup and operation of shortcut nitrification for ammonium-rich sludge digester liquids were optimized. The control strategy works well to keep the reactor operation in steady state and in achieving high-efficiency for shortcut nitrification.

关键词： internal-loop airlift bioreactor shortcut nitrification orthogonal experiment control strategy sludge digester liquids

Model Predictive control strategy of Multi-Port Interline DC Power Flow controller

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Energy Engineering 2023年第10期120卷 2251-2272页

作者： He Wang Xiangsheng Xu Guanye Shen Bian Jing Key Laboratory of Modern Power System Simulation and control&Renewable Energy Technology Ministry of Education(Northeast Electric Power University)Jilin132012China Marketing Department State Grid Jilin Electric Power Co.Ltd.Changchun130061China

There are issues with flexible DC transmission system such as a lack of control freedom over power flow.In order to tackle these issues,a DC power flow controller(DCPFC)is incorporated into a multi-terminal,flexible DC power grid.In recent years,a multi-port DC power flow controller based on a modular multi-level converter has become a focal point of research due to its simple structure and robust scalability.This work proposes a model predictive control(MPC)strategy for multi-port interline DC power flow controllers in order to improve their steady-state dynamic performance.Initially,the mathematical model of a multi-terminal DC power grid with a multi-port interline DC power flow controller is developed,and the relationship between each regulated variable and control variable is determined;The power flow controller is then discretized,and the cost function and weight factor are built with numerous control objectives.Sub module sorting method and nearest level approximation modulation regulate the power flow controller;Lastly,theMATLAB/Simulink simulation platformis used to verify the correctness of the establishedmathematicalmodel and the control performance of the suggestedMPC strategy.Finally,it is demonstrated that the control strategy possesses the benefits of robust dynamic performance,multiobjective control,and a simple structure.

关键词： DC power flow controller model predictive control modular multi-level converter control strategy dynamic performance

Simulation Study of the control strategy of a DC Inverter Heat Pump Using a DC Distribution Network

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Energy Engineering 2023年第6期120卷 1421-1444页

作者： Siwei Han Xianglong Li Wei Zhao Linyu Wang Anqi Liang Shuang Zeng State Grid(Suzhou)City and Energy Research Institute SuzhouChina Electric Power Research Institute of State Grid Beijing Electric Power Company BeijingChina

Photovoltaics,energy storage,direct current and flexibility(PEDF)are important pillars of achievement on the path to manufacturing nearly zero energy buildings(NZEBs).HVAC systems,which are an important part of public buildings,play a key role in adapting to PDEF systems.This research studied the basic principles and operational control strategies of a DC inverter heat pump using a DC distribution network with the aim of contributing to the development and application of small DC distribution systems.Along with the characteristics of a DC distribution network and different operating conditions,a DC inverter heat pump has the ability to adapt to changes in the DC bus voltage and adds flexibility to the system.Theoretical models of the DC inverter heat pump integrated with an ice storage unit were developed.The control strategies of the DC inverter heat pump system considered the influence of both room temperature and varied bus voltage.A simulation study was conducted using MATLAB&Simulink software with simulation results validated by experimental data.The results showed that:(1)The bus fluctuation under the rated working voltage had little effect on the operation of the unit;(2)When the bus voltage was fluctuating from 80%-90%or 105%-107%,the heat pump could still operate normally by reducing the frequency;(3)When the bus voltage was less than 80%or more than 107%,the unit needed to be shut down for the sake of equipment safety,so that the energy storage device could adjust to the sharp decrease or rise of voltage.

关键词： Photovoltaics energy storage direct current and flexibility DC inverter heat pump MATLAB&Simulink control strategy

Dynamic emission characteristics and control strategies of air pollutants from motor vehicles in downtown Beijing,China

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Journal of Environmental Sciences 2024年第2期136卷 637-646页

作者： Yan Shen Tongran Wu Aiping Lian Jie Gao Fei Peng Guohua Song Xuefang Wu Yangyang Cui Xinyu Liu Yunfei Wan Jing Yan Yifeng Xue National Engineering Research Center of Urban Environmental Pollution control Beijing Municipal Research Institute of Eco-Environmental ProtectionBeijing 100037China Beijing Municipal Ecology and Environment Bureau Beijing 100048China Beijing Jiaotong University Beijing 100091China

This study combined the real-time monitoring and investigation of traffic flows to comprehensively analyze the road traffic flow and vehicle structure in downtown Beijing.A dynamic emission inventory of motor vehicle air pollutants in downtown Beijing in 2021 was established,and the impact of these emissions on air quality was simulated and quantified,and different emission reduction control scenarios were proposed to evaluate their environmental improvement effects and explore measures to mitigate the impact of pollution emissions.The results show that the high traffic flow and the structure of the motor vehicle emissions in downtown Beijing are the main causes of severe motor vehicle pollution.Monitoring data shows that traffic flow in central Beijing is dominated by small passenger vehicles,while the vehicle mix is better than in other regions,with 72.0%of vehicles meeting"National V"or higher emission standards.However,to achieve higher air quality goals,further reducing vehicle emissions is necessary.Based on dynamic traffic flow,the average daily emissions of nitrogen oxides(NOX),particulate matters(PM_(2.5))and volatile organic compounds(VOC)from motor vehicles in central Beijing are 17.7 tons,0.6 tons and 14.0 tons,respectively,accounting for 23.0%of the city’s average daily motor vehicle emissions.If a zero-emission zone for motor vehicles were implemented in central Beijing,the annual average emission level of pollutants will be reduced by 10.4%to 21.0%.The designation of ultra-low emission zones for motor vehicles could be effective in improving the air quality in the center of Beijing.

关键词： Motor vehicle Air pollutant Emission characteristics control strategy Beijing

Renewable Microgrid Protection strategy Coordinating with Current-based Fault control

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Journal of Modern Power Systems and Clean Energy 2022年第6期10卷 1679-1689页

作者： Zihao Wang Longhua Mu Chongkai Fang College of Electronics and Information Engineering Tongji UniversityShanghai 201804China

The renewable microgrid(RMG)is a critical way to organize and utilize new energy.Its control and protection strategies during the fault are the core technologies to ensure the safe operation and stability of the system.The traditional protection principles are unsuitable for RMGs due to the flexibility of RMG operation,the complexity of RMG topology,and the variety of fault control strategies of inverter-interfaced distributed generators(IIDGs).The traditional fault component protection principle is affected by the low voltage ride-through(LVRT)control strategy and will fail in some scenarios.In order to make the fault component protection principle available in every scenario,a current-based fault control strategy is proposed.Specific fault characteristics are generated by the grid-feeding IIDGs during the fault so they can be equivalent to the open circuits,and the fault models in additional network can be simplified.By analyzing the fault characteristics,an RMG protection strategy based on the current-based fault control of IIDGs is presented.The fault directions of feeders can be distinguished and the fault feeder can be located accurately in both grid-connected and islanded RMGs.Then,the grid-feeding IIDGs can transit to LVRT mode smoothly.Thus,IIDGs are considered comprehensively in terms of coordinating with fault control and fault characteristic generation.Finally,the experimental results of the hardware platform prove the effectiveness of the proposed current-based fault control strategy,and the simulation results based on PSCAD/EMTDC verify the correctness of the protection strategy.

关键词： Renewable microgrid protection strategy fault characteristic control strategy fault component

control strategy for wayside supercapacitor energy storage system in railway transit network

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Journal of Modern Power Systems and Clean Energy 2014年第2期2卷 181-190页

作者： Zongyu GAO Jianjun FANG Yinong ZHANG Di SUN College of Automation of Beijing Union University Beijing 100101China School of Electrical Engineering Beijing Jiaotong UniversityBeijing 100044China

This paper discusses the control strategy for energy management in railway transit network with wayside(substation)supercapacitor(SC)energy storage system(ESS).Firstly,the structure of the wayside energy storage system is introduced.Secondly,the model of energy storage system is built and the control strategy is described.Thirdly,in order to estimate the required energy storage system,a useful method is proposed to predict the instantaneous regenerative energy magnitude which is delivered to each substation.Finally,the ESS configuration for each substation is determined.A simplified mathematical model of the whole metro network is established and the main features of the control strategy are developed.Numerical simulations show the efficacy of suggested control strategy and the energy saving obtained for railway transit network.

关键词： Supercapacitor(SC) Energy storage system(ESS) Regeneration failure control strategy Railway transit network

Development of Wheel-Legged Biped Robots:A Review

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Journal of Bionic Engineering 2024年第2期21卷 607-634页

作者： Xuefei Liu Yi Sun Shikun Wen Kai Cao Qian Qi Xiaoshu Zhang Huan Shen Guangming Chen Jiajun Xu Aihong Ji Lab of Locomotion Bioinspiration and Intelligent Robots College of Mechanical and Electrical EngineeringNanjing University of Aeronautics and Astronautics29 Yudao StreetNanjing210016China State Key Laboratory of Mechanics and control for Aerospace Structures Nanjing University of Aeronautics and AstronauticsNanjing210016China

The wheel-legged biped robot is a typical ground-based mobile robot that can combine the high velocity and high efficiency pertaining to wheeled motion and the strong,obstacle-crossing performance associated with legged motion.These robots have gradually exhibited satisfactory application potential in various harsh scenarios such as rubble rescue,military operations,and wilderness exploration.Wheel-legged biped robots are divided into four categories according to the open–close chain structure forms and operation task modes,and the latest technology research status is summarized in this paper.The hardware control system,control method,and application are analyzed,and the dynamic balance control for the two-wheel,biomimetic jumping control for the legs and whole-body control for integrating the wheels and legs are analyzed.In summary,it is observed that the current research exhibits problems,such as the insufficient application of novel materials and a rigid–flexible coupling design;the limited application of the advanced,intelligent control methods;the inadequate understanding of the bionic jumping mechanisms in robot legs;and the insufficient coordination ability of the multi-modal motion,which do not exhibit practical application for the wheel-legged biped robots.Finally,this study discusses the key research directions and development trends for the wheel-legged biped robots.

关键词： Wheel-legged biped robot Wheeled motion Legged motion control strategy

Ground-Based Hyperspectral Stereoscopic Remote Sensing Network: A Promising strategy to Learn Coordinated control of O_(3) and PM_(2.5) over China

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Engineering 2022年第12期19卷 71-83页

作者： Cheng Liu Chengzhi Xing Qihou Hu Qihua Li Haoran Liu Qianqian Hong Wei Tan Xiangguang Ji Hua Lin Chuan Lu Jinan Lin Hanyang Liu Shaocong Wei Jian Chen Kunpeng Yang Shuntian Wang Ting Liu Yujia Chen Department of Precision Machinery and Precision Instrumentation University of Science and Technology of ChinaHefei 230026China Center for Excellence in Regional Atmospheric Environment Institute of Urban EnvironmentChinese Academy of SciencesXiamen 361021China Key Lab of Environmental Optics and Technology Anhui Institute of Optics and Fine MechanicsHefei Institutes of Physical ScienceChinese Academy of SciencesHefei 230031China Key Laboratory of Precision Scientific Instrumentation of Anhui Higher Education Institutes University of Science and Technology of ChinaHefei 230026China Anhui Province Key Laboratory of Polar Environment and Global Change University of Science and Technology of ChinaHefei 230026China School of Earth and Space Sciences University of Science and Technology of ChinaHefei 230026China School of Environmental Science and Optoelectronic Technology University of Science and Technology of ChinaHefei 230026China Institute of Physical Science and Information Technology Anhui UniversityHefei 230601China School of Environment and Civil Engineering Jiangnan UniversityWuxi 214122China

With the coming of the“14th Five-Year Plan,”the coordinated control of particulate matter with an aerodynamic diameter no greater than 2.5 lm(PM_(2.5))and O_(3) has become a major issue of air pollution prevention and control in China.The stereoscopic monitoring of regional PM_(2.5) and O_(3) and their precursors is crucial to achieve coordinated control.However,current monitoring networks are currently inadequate for monitoring the vertical profiles of both PM_(2.5) and O_(3) simultaneously and support air quality control.The University of Science and Technology of China(USTC)has established a nationwide ground-based hyperspectral stereoscopic remote sensing network based on multi-axis differential optical absorption spectroscopy(MAX-DOAS)since 2015.This monitoring network provides a significant opportunity for the regional coordinated control of PM_(2.5) and O_(3) in China.One-year vertical profiles of aerosol,NO_(2) and HCHO monitored from four MAX-DOAS stations installed in four megacities(Beijing,Shanghai,Shenzhen,and Chongqing)were used to characterize their vertical distribution differences in four key regions,Jing–Jin–Ji(JJJ),Yangtze River Delta(YRD),Pearl River Delta(PRD),and Sichuan Basin(SB),respectively.The normalized and yearly averaged aerosol vertical profiles below 400 m in JJJ and PRD exhibit a box shape and a Gaussian shape,respectively,and both show exponential shapes in YRD and SB.The NO_(2) vertical profiles in four regions all exhibit exponential shapes because of vehicle emissions.The shape of the HCHO vertical profile in JJJ and PRD was Gaussian,whereas an exponential shape was shown in YRD and SB.Moreover,a regional transport event occurred at an altitude of 600–1000 m was monitored in the southwest–northeast pathway of the North China Plain(NCP)by five MAX-DOAS stations(Shijiazhuang(SJZ),Wangdu(WD),Nancheng(NC),Chinese Academy of Meteorological Sciences(CAMS),and University of Chinese Academy of Sciences(UCAS))belonging to the above network.The aerosol optical depths(AOD)in these five st

关键词： MAX-DOAS Stereoscopic monitoring Regional transport Ozone production control strategy

Path Planning and Tracking control for Parking via Soft Actor-Critic Under Non-Ideal Scenarios

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IEEE/CAA Journal of Automatica Sinica 2024年第1期11卷 181-195页

作者： Xiaolin Tang Yuyou Yang Teng Liu Xianke Lin Kai Yang Shen Li IEEE the College of Mechanical and Vehicle Engineering Chongqing UniversityChongqing 400044China the Clinical Research Center and Medical Pathology Center Chongqing University Three Gorges HospitalChongqing UniversityWanzhou 404000 the Department of Automotive and Mechatronics Engineering Ontario Tech UniversityOshawa ON LIG OC5Canada the School of Civil Engineering Tsinghua UniversityBeijing 100084China

Parking in a small parking lot within limited space poses a difficult task. It often leads to deviations between the final parking posture and the target posture. These deviations can lead to partial occupancy of adjacent parking lots, which poses a safety threat to vehicles parked in these parking lots. However, previous studies have not addressed this issue. In this paper, we aim to evaluate the impact of parking deviation of existing vehicles next to the target parking lot(PDEVNTPL) on the automatic ego vehicle(AEV) parking, in terms of safety, comfort, accuracy, and efficiency of parking. A segmented parking training framework(SPTF) based on soft actor-critic(SAC) is proposed to improve parking performance. In the proposed method, the SAC algorithm incorporates strategy entropy into the objective function, to enable the AEV to learn parking strategies based on a more comprehensive understanding of the environment. Additionally, the SPTF simplifies complex parking tasks to maintain the high performance of deep reinforcement learning(DRL). The experimental results reveal that the PDEVNTPL has a detrimental influence on the AEV parking in terms of safety, accuracy, and comfort, leading to reductions of more than 27%, 54%, and 26%respectively. However, the SAC-based SPTF effectively mitigates this impact, resulting in a considerable increase in the parking success rate from 71% to 93%. Furthermore, the heading angle deviation is significantly reduced from 2.25 degrees to 0.43degrees.

关键词： Automatic parking control strategy parking deviation(APS) soft actor-critic(SAC)