An ensemble-based method for the observation system simulation experiment(OSSE)is employed to design optimal observation stations and assess the present observation stations in the northeastern South China Sea(SCS).We...An ensemble-based method for the observation system simulation experiment(OSSE)is employed to design optimal observation stations and assess the present observation stations in the northeastern South China Sea(SCS).We employed the 20-year(1992-2012)sea surface height(SSH)data to design an array to monitor the intraseasonal to interannual variability.The results show that the most key region was found located at the northwest of Luzon Island(LI)where the energetic Luzon cyclonic gyre(LCG)occurs;other key regions include the edge of the LCG,the northwest of the Luzon Strait(LS),and the southwest of Taiwan,China.By contrast,we found that the present observation stations might oversample at the northwest of the LS and undersample at the northwest of LI.In addition,the optimal stations perform better in a larger area than the present stations.In vertical direction,the key layer is located within the upper 200-m depth,of which the surface and subsurface layers are most valuable to the observing system.展开更多
Nowadays,the efficient and cleaner utilization of coal have attracted wide attention due to the rich coal and rare oil/gas resources structure in China.Coal chemical looping gasification(CCLG)is a promising coal utili...Nowadays,the efficient and cleaner utilization of coal have attracted wide attention due to the rich coal and rare oil/gas resources structure in China.Coal chemical looping gasification(CCLG)is a promising coal utilization technology to achieve energy conservation and emission reduction targets for highly pure synthesis gas.As a downstream product of synthesis gas,methyl methacrylate(MMA),is widely used as raw material for synthesizing polymethyl methacrylate and resin products with excellent properties.So this paper proposes a novel system integrating MMA production and CCLG(CCLG-MMA)processes aiming at"energy saving and low emission",in which the synthesis gas produced by CCLG and purified by dry methane reforming(DMR)reaction and Rectisol process reacts with ethylene for synthesizing MMA.Firstly,the reaction mechanism of CCLG is investigated by using Reactive force field(ReaxFF)MD simulation based on atomic models of char and oxygen carrier(Fe_(2)O_(3))for obtaining optimum reaction temperature of fuel reactor(FR).Secondly,the steady-state simulation of CCLG-MMA system is carried out to verify the feasibility of MMA production.The amount of CO_(2)emitted by CCLG process and DMR reaction is 0.0028(kg CO_(2))^(-1)·(kg MMA)^(-1).The total energy consumption of the CCLG-MMA system is 45521 kJ·(kg MMA)^(-1),among which the consumption of MMA production part is 25293 k(·kg MMA)^(-1).The results show that the CCLG-MMA system meets CO_(2)emission standard and has lower energy consumption compared to conventional MMA production process.Finally,one control scheme is designed to verify the stability of CCLG-MMA system.The CCLG-MMA integration strategy aims to obtain highly pure MMA from multi-scale simulation perspectives,so this is an optimal design regarding all factors influencing cleaner MMA production.展开更多
To meet the rising demand of performing complex tasks in a highly technologized world,the development of mechatronic systems faces two major challenges:First,the system is integrated in a fast changing environment and...To meet the rising demand of performing complex tasks in a highly technologized world,the development of mechatronic systems faces two major challenges:First,the system is integrated in a fast changing environment and has to cope with dynamically modified tasks and circumstances.At the same time,the development of new methods has to be fast,cost-effective and efficient.By taking care of both aspects simultaneously,simulations have become an acknowledged tool to cost-effectively and rapidly test and optimize new solutions for complex mechatronic systems,as they are common in,e.g.,robotics.Mostly,simulation methods are specialized for one purpose and thus used as a stand-alone tool to analyze the behavior of single components or certain aspects of the whole system.But with size and complexity of the system,the susceptibility to errors rises when the interaction between components fails.If a component shows minimal deviations to its nominal behavior,huge interdependencies between components of complex systems might cause system failure.The structural behavior of a single component is therefore as crucial to the functionality of the whole system as the interplay of all components.Both aspects have to be analyzed in parallel,which is nowadays barely considered.Consequently,this work presents the integration of structural simulations into the overall picture.The developed approach consists of a concept,an implementation and the validation for an automated bidirectional interaction to integrate results from Finite Element Analysis(FEA)into an existing,real-time capable Overall System Simulation for mechatronic systems in general and robotics in particular.展开更多
The access to electricity in rural areas is extremely limited, but it is crucial for all citizens. The population in rural areas of sub-Saharan African (SSA) countries is generally low, making it economically unfeasib...The access to electricity in rural areas is extremely limited, but it is crucial for all citizens. The population in rural areas of sub-Saharan African (SSA) countries is generally low, making it economically unfeasible to implement traditional rural electrification (CRE) projects due to the high cost of establishing the necessary distribution infrastructure. To address this cost issue, one alternative technology for rural electrification (URE) that can be explored is the Capacitor Coupled Substation (CCS) technology. CCS is a cost-effective solution for supplying electricity to rural areas. The research is necessitated by the need to offer a cost-effective technology for supplying electricity to sparsely populated communities. This paper examines the impact on the transmission network when a 400 kV/400V CCS is connected to it. The system response when a CCS is connected to the network was modeled using MATLAB/Si-mulink. The results, based on the fixed load of 80 kW, showed negligible interference on the transmission line voltage. However, there was minor impact on the parameters downstream of the tapping point. These findings were further supported by introducing a fault condition to the CCS, which showed that interferences with the CCS could affect the overall stability of the transmission network downstream of the tapping node, similar to the behavior of an unstable load.展开更多
This paper focuses on the distribution of passenger flow in Huoying Station,Line 13 of Beijing subway system.The transformation measures taken by Line 13 since operation are firstly summarized.Then the authors elabora...This paper focuses on the distribution of passenger flow in Huoying Station,Line 13 of Beijing subway system.The transformation measures taken by Line 13 since operation are firstly summarized.Then the authors elaborate the facilities and equipment of this station,especially the node layout and passenger flow field.An optimization scheme is proposed to rapidly distribute the passenger flow in Huoying Station by adjusting the operation time of the escalator in the direction of Xizhimen.The authors adopt Queuing theory and Anylogic simulation software to simulate the original and the optimized schemes of Huoying Station to distribute the passenger flow.The results of the simulation indicate that the optimized scheme could effectively alleviate the traffic congestion in the hall of Huoying Station,and the pedestrian density in other places of the hall is lowered;passengers could move freely in the hall and no new congestion points would form.The rationality of the scheme is thus proved.展开更多
Hybrid Petri nets(HPNs) are widely used to describe and analyze various industrial hybrid systems that have both discrete-event and continuous discrete-time behaviors. Recently,many researchers attempt to utilize them...Hybrid Petri nets(HPNs) are widely used to describe and analyze various industrial hybrid systems that have both discrete-event and continuous discrete-time behaviors. Recently,many researchers attempt to utilize them to characterize power and energy systems. This work proposes to adopt an HPN to model and analyze a microgrid that consists of green energy sources. A reachability graph for such a model is generated and used to analyze the system properties.展开更多
The research on complex systems is different from that on general systems because the former must consider self-organization,emergence,uncertainty,predetermination,and evolution.As an important method to transform the...The research on complex systems is different from that on general systems because the former must consider self-organization,emergence,uncertainty,predetermination,and evolution.As an important method to transform the world,a simulation is one of the most important skills to discover complex systems.In this study,we provide a survey on complex systems and their simulation methods.Initially,the development history of complex system research is summarized from two main lines.Then,the eight common characteristics of the most complex systems are presented.Furthermore,the simulation methods of complex systems are introduced in detail from four aspects,namely,meta-synthesis methods,complex networks,intelligent technologies,and other methods.From the overall point of view,intelligent technologies are the driving force,and complex networks are the advanced structure.Meta-synthesis methods are the integration strategy,and other methods are the supplements.In addition,we show three complex system simulation examples:digital reactor simulation,simulation of a logistics system in the industrial site,and crowd evacuation simulation.The examples show that a simulation is a useful means and an important method in complex system research.Finally,the future development prospects for complex systems and their simulation methods are suggested.展开更多
In this paper, several sets of observing system simulation experiments (OSSEs) were designed for three typhoon cases to determine whether or not the additional observation data in the sensitive regions identified by c...In this paper, several sets of observing system simulation experiments (OSSEs) were designed for three typhoon cases to determine whether or not the additional observation data in the sensitive regions identified by conditional nonlinear optimal perturbations (CNOPs) could improve the short-range forecast of typhoons. The results show that the CNOPs capture the sensitive regions for typhoon forecasts, which implies that conducting additional observation in these specific regions and eliminating initial errors could reduce forecast errors. It is inferred from the results that dropping sondes in the CNOP sensitive regions could lead to improvements in typhoon forecasts.展开更多
In this study,a moored array optimization tool(MAOT)was developed and applied to the South China Sea(SCS)with a focus on three-dimensional temperature and salinity observations.Application of the MAOT involves two ste...In this study,a moored array optimization tool(MAOT)was developed and applied to the South China Sea(SCS)with a focus on three-dimensional temperature and salinity observations.Application of the MAOT involves two steps:(1)deriving a set of optimal arrays that are independent of each other for different variables at different depths based on an empirical orthogonal function method,and(2)consolidating these arrays using a K-center clustering algorithm.Compared with the assumed initial array consisting of 17 mooring sites located on a 3°×3°horizontal grid,the consolidated array improved the observing ability for three-dimensional temperature and salinity in the SCS with optimization efficiencies of 19.03%and 21.38%,respectively.Experiments with an increased number of moored sites showed that the most cost-effective option is a total of 20 moorings,improving the observing ability with optimization efficiencies up to 26.54%for temperature and 27.25%for salinity.The design of an objective array relies on the ocean phenomenon of interest and its spatial and temporal scales.In this study,we focus on basin-scale variations in temperature and salinity in the SCS,and thus our consolidated array may not well resolve mesoscale processes.The MAOT can be extended to include other variables and multi-scale variability and can be applied to other regions.展开更多
Charging infrastructure supports the rapid development of China's new energy vehicle industry.It not only plays a decisive role in providing accessible and convenient services for electric vehicle(EV)users but als...Charging infrastructure supports the rapid development of China's new energy vehicle industry.It not only plays a decisive role in providing accessible and convenient services for electric vehicle(EV)users but also,in one of the seven new infrastructure areas,plays an important role in stabilizing growth and unleashing economic potential during the new coronavirus(COVID-19)pandemic,impacting China's economy.In this study,the system dynamics model was used to predict the development of the EV industry and the demand for charging infrastructure,while considering the influence of policy,increase in EV mileage,and consumer purchase intention index.Furthermore,using the matching of EVs and charging infrastructure in Beijing and policy oriented sensitivity analysis,a simulation of the construction of battery swap taxis and power stations under three policy scenarios was conducted.This research shows that with policies implemented to support charging infrastructure and swapping compatible taxis,Beijing can achieve its goal of replacing all EVs with fast-swap batteries and fast-charging functions within three years.展开更多
In order to obtain stable and high-precision motion tracking in mixed reality(MR)simulation of the complex system,an optical-inertial hybrid tracking method is proposed,which combines the accuracy of optical motion ca...In order to obtain stable and high-precision motion tracking in mixed reality(MR)simulation of the complex system,an optical-inertial hybrid tracking method is proposed,which combines the accuracy of optical motion capture equipment and the robustness of inertial motion capture equipment,and can reduce the occlusion problem of entity scene on the premise of ensuring the localization accuracy.The method has been applied to the ergonomic evaluation of large civil aircraft development processes,and the effectiveness and usability of the method have been verified.展开更多
With wider applications of power electronic devices in modern power systems,simulation using traditional electro-mechanical and electromagnetic simulation tools suffer from low speed and imprecision.Multi-rate technol...With wider applications of power electronic devices in modern power systems,simulation using traditional electro-mechanical and electromagnetic simulation tools suffer from low speed and imprecision.Multi-rate technologies can greatly improve simulation efficiency by avoiding simulating the entire system using a small time-step.However,the drawbacks of the current synchronization mechanisms is that they introduce numerical errors and numerical instabilities in multi-rate parallel simulations.An improved multi-rate parallel technology,node splitting interface(NSI),is proposed to reduce errors and enhance simulation stability.A new synchronization mechanism is used to avoid prediction and signal delays.Theoretical analyses are carried out to prove the convergence and absolute stability of the proposed NSI algorithm.This algorithm is particularly suitable for simultaneously investigating long term dynamics of DC grids and fast transients of power electronic converters.展开更多
The energy conservation plays an important role for low carbon development.In order to evaluate the energy conservation in the full life-cycle,a scheme to estimate the energy consumption,or alternatively the energy pa...The energy conservation plays an important role for low carbon development.In order to evaluate the energy conservation in the full life-cycle,a scheme to estimate the energy consumption,or alternatively the energy pay,in constructing an overhead transmission line is proposed in this paper.The analysis of a typical projection is given for demonstration.With new additional overhead transmission lines,the energy consumption,known as the power loss in power network,is expected to be decline,which is defined in this paper as the energy payback.In order to estimate this kind of contribution,the scheme that consisted of load forecast,production simulation for generating systems,load flow simulation and power loss calculation has been proposed.Case studies,based on the IEEE 24-bus test system,are given to demonstrate the efficacy of the schemes.Moreover,several presumptive scenarios are deployed and analysed with the presented schemes for comparison.展开更多
The edge computing model enables real-time and low-power processing of data,while contributing to data security and privacy protection.However,the heterogeneity and diversity of edge computing devices pose a great cha...The edge computing model enables real-time and low-power processing of data,while contributing to data security and privacy protection.However,the heterogeneity and diversity of edge computing devices pose a great challenge to task scheduling and migration.Most of the existing studies only consider the allocation of computational resources,but lack comprehensive consideration of data resources,storage space,etc.In this paper,we proposed intelligent scheduling strategies for computing power resources in heterogeneous edge networks.We define the relevant models and construct a comprehensive matching matrix in terms of task matching with computing resources,data resources,storage resources,load balancing of computing devices and storage space matching,and design an intelligent scheduling algorithm based on iteration and load balancing according to the matching degree of tasks and computing devices in the heterogeneous edge network environment.The iterative and load-balanced scheduling algorithm is based on the least-cost flow solution scheduling strategy,which effectively reduces the task computation response time and improves the computation and storage resource utilization of computing devices.Experimental validation of the proposed intelligent scheduling strategy is carried out based on a simulation environment.The experimental results show that the proposed intelligent scheduling strategy has obvious advantages over random scheduling methods in terms of task processing delay,computing power resource utilization and number of satisfactory tasks.展开更多
基金Supported by the National Key Research&Development Plan of China(Nos.2016YFC1401703,2016YFC1401702,2018YFC0309803)the National Natural Science Foundation of China(Nos.41506002,41676010,41476011,41676015,41606026)+1 种基金the Institution of South China Sea Ecology and Environmental Engineering,Chinese Academy of Sciences(No.ISEE2019ZR0)the Guangzhou Science and Technology Foundation(No.201804010133)。
文摘An ensemble-based method for the observation system simulation experiment(OSSE)is employed to design optimal observation stations and assess the present observation stations in the northeastern South China Sea(SCS).We employed the 20-year(1992-2012)sea surface height(SSH)data to design an array to monitor the intraseasonal to interannual variability.The results show that the most key region was found located at the northwest of Luzon Island(LI)where the energetic Luzon cyclonic gyre(LCG)occurs;other key regions include the edge of the LCG,the northwest of the Luzon Strait(LS),and the southwest of Taiwan,China.By contrast,we found that the present observation stations might oversample at the northwest of the LS and undersample at the northwest of LI.In addition,the optimal stations perform better in a larger area than the present stations.In vertical direction,the key layer is located within the upper 200-m depth,of which the surface and subsurface layers are most valuable to the observing system.
基金supported by the National Natural Science Foundation of China(21576143)Foundation of State Key Laboratory of High-efficiency Utilization of Coal and Green Chemical Engineering(2020-KF-13)。
文摘Nowadays,the efficient and cleaner utilization of coal have attracted wide attention due to the rich coal and rare oil/gas resources structure in China.Coal chemical looping gasification(CCLG)is a promising coal utilization technology to achieve energy conservation and emission reduction targets for highly pure synthesis gas.As a downstream product of synthesis gas,methyl methacrylate(MMA),is widely used as raw material for synthesizing polymethyl methacrylate and resin products with excellent properties.So this paper proposes a novel system integrating MMA production and CCLG(CCLG-MMA)processes aiming at"energy saving and low emission",in which the synthesis gas produced by CCLG and purified by dry methane reforming(DMR)reaction and Rectisol process reacts with ethylene for synthesizing MMA.Firstly,the reaction mechanism of CCLG is investigated by using Reactive force field(ReaxFF)MD simulation based on atomic models of char and oxygen carrier(Fe_(2)O_(3))for obtaining optimum reaction temperature of fuel reactor(FR).Secondly,the steady-state simulation of CCLG-MMA system is carried out to verify the feasibility of MMA production.The amount of CO_(2)emitted by CCLG process and DMR reaction is 0.0028(kg CO_(2))^(-1)·(kg MMA)^(-1).The total energy consumption of the CCLG-MMA system is 45521 kJ·(kg MMA)^(-1),among which the consumption of MMA production part is 25293 k(·kg MMA)^(-1).The results show that the CCLG-MMA system meets CO_(2)emission standard and has lower energy consumption compared to conventional MMA production process.Finally,one control scheme is designed to verify the stability of CCLG-MMA system.The CCLG-MMA integration strategy aims to obtain highly pure MMA from multi-scale simulation perspectives,so this is an optimal design regarding all factors influencing cleaner MMA production.
基金This work is part of the project“iBOSS-3”supported by the German Aerospace Center(DLR)with funds of the German Federal Ministry of Economics and Tech-nology(BMWi),support code 50 RA 1504.
文摘To meet the rising demand of performing complex tasks in a highly technologized world,the development of mechatronic systems faces two major challenges:First,the system is integrated in a fast changing environment and has to cope with dynamically modified tasks and circumstances.At the same time,the development of new methods has to be fast,cost-effective and efficient.By taking care of both aspects simultaneously,simulations have become an acknowledged tool to cost-effectively and rapidly test and optimize new solutions for complex mechatronic systems,as they are common in,e.g.,robotics.Mostly,simulation methods are specialized for one purpose and thus used as a stand-alone tool to analyze the behavior of single components or certain aspects of the whole system.But with size and complexity of the system,the susceptibility to errors rises when the interaction between components fails.If a component shows minimal deviations to its nominal behavior,huge interdependencies between components of complex systems might cause system failure.The structural behavior of a single component is therefore as crucial to the functionality of the whole system as the interplay of all components.Both aspects have to be analyzed in parallel,which is nowadays barely considered.Consequently,this work presents the integration of structural simulations into the overall picture.The developed approach consists of a concept,an implementation and the validation for an automated bidirectional interaction to integrate results from Finite Element Analysis(FEA)into an existing,real-time capable Overall System Simulation for mechatronic systems in general and robotics in particular.
文摘The access to electricity in rural areas is extremely limited, but it is crucial for all citizens. The population in rural areas of sub-Saharan African (SSA) countries is generally low, making it economically unfeasible to implement traditional rural electrification (CRE) projects due to the high cost of establishing the necessary distribution infrastructure. To address this cost issue, one alternative technology for rural electrification (URE) that can be explored is the Capacitor Coupled Substation (CCS) technology. CCS is a cost-effective solution for supplying electricity to rural areas. The research is necessitated by the need to offer a cost-effective technology for supplying electricity to sparsely populated communities. This paper examines the impact on the transmission network when a 400 kV/400V CCS is connected to it. The system response when a CCS is connected to the network was modeled using MATLAB/Si-mulink. The results, based on the fixed load of 80 kW, showed negligible interference on the transmission line voltage. However, there was minor impact on the parameters downstream of the tapping point. These findings were further supported by introducing a fault condition to the CCS, which showed that interferences with the CCS could affect the overall stability of the transmission network downstream of the tapping node, similar to the behavior of an unstable load.
基金This research is supported by Beijing Municipal Natural Science Foundation(9204023)Ministry of Education“Tiancheng Huizhi”Innovation and Education Promotion Foundation(2018A01012).
文摘This paper focuses on the distribution of passenger flow in Huoying Station,Line 13 of Beijing subway system.The transformation measures taken by Line 13 since operation are firstly summarized.Then the authors elaborate the facilities and equipment of this station,especially the node layout and passenger flow field.An optimization scheme is proposed to rapidly distribute the passenger flow in Huoying Station by adjusting the operation time of the escalator in the direction of Xizhimen.The authors adopt Queuing theory and Anylogic simulation software to simulate the original and the optimized schemes of Huoying Station to distribute the passenger flow.The results of the simulation indicate that the optimized scheme could effectively alleviate the traffic congestion in the hall of Huoying Station,and the pedestrian density in other places of the hall is lowered;passengers could move freely in the hall and no new congestion points would form.The rationality of the scheme is thus proved.
基金supported by the Deanship of Scientific Research(DSR)King Abdulaziz University,Jeddah(23-135-35-HiCi)
文摘Hybrid Petri nets(HPNs) are widely used to describe and analyze various industrial hybrid systems that have both discrete-event and continuous discrete-time behaviors. Recently,many researchers attempt to utilize them to characterize power and energy systems. This work proposes to adopt an HPN to model and analyze a microgrid that consists of green energy sources. A reachability graph for such a model is generated and used to analyze the system properties.
基金This work was supported in part by the National Key Research and Development Program of China(No.2020YFC1523100)the National Natural Science Foundation of China(Nos.62176083,61673156,and 61877016).
文摘The research on complex systems is different from that on general systems because the former must consider self-organization,emergence,uncertainty,predetermination,and evolution.As an important method to transform the world,a simulation is one of the most important skills to discover complex systems.In this study,we provide a survey on complex systems and their simulation methods.Initially,the development history of complex system research is summarized from two main lines.Then,the eight common characteristics of the most complex systems are presented.Furthermore,the simulation methods of complex systems are introduced in detail from four aspects,namely,meta-synthesis methods,complex networks,intelligent technologies,and other methods.From the overall point of view,intelligent technologies are the driving force,and complex networks are the advanced structure.Meta-synthesis methods are the integration strategy,and other methods are the supplements.In addition,we show three complex system simulation examples:digital reactor simulation,simulation of a logistics system in the industrial site,and crowd evacuation simulation.The examples show that a simulation is a useful means and an important method in complex system research.Finally,the future development prospects for complex systems and their simulation methods are suggested.
基金sponsored by the National Natural Science Foundation of China (Grant Nos. 40830955 and 40821092)the Project of China Meteorological Administration (Grant No. GYHY200906009)
文摘In this paper, several sets of observing system simulation experiments (OSSEs) were designed for three typhoon cases to determine whether or not the additional observation data in the sensitive regions identified by conditional nonlinear optimal perturbations (CNOPs) could improve the short-range forecast of typhoons. The results show that the CNOPs capture the sensitive regions for typhoon forecasts, which implies that conducting additional observation in these specific regions and eliminating initial errors could reduce forecast errors. It is inferred from the results that dropping sondes in the CNOP sensitive regions could lead to improvements in typhoon forecasts.
基金The National Key Research and Development Program of China under contract No.2019YFC1408400the National Natural Science Foundation of China under contract No.41876029.
文摘In this study,a moored array optimization tool(MAOT)was developed and applied to the South China Sea(SCS)with a focus on three-dimensional temperature and salinity observations.Application of the MAOT involves two steps:(1)deriving a set of optimal arrays that are independent of each other for different variables at different depths based on an empirical orthogonal function method,and(2)consolidating these arrays using a K-center clustering algorithm.Compared with the assumed initial array consisting of 17 mooring sites located on a 3°×3°horizontal grid,the consolidated array improved the observing ability for three-dimensional temperature and salinity in the SCS with optimization efficiencies of 19.03%and 21.38%,respectively.Experiments with an increased number of moored sites showed that the most cost-effective option is a total of 20 moorings,improving the observing ability with optimization efficiencies up to 26.54%for temperature and 27.25%for salinity.The design of an objective array relies on the ocean phenomenon of interest and its spatial and temporal scales.In this study,we focus on basin-scale variations in temperature and salinity in the SCS,and thus our consolidated array may not well resolve mesoscale processes.The MAOT can be extended to include other variables and multi-scale variability and can be applied to other regions.
基金This research was funded by the National Social Science Fund of China[Grant number.16AGL004].
文摘Charging infrastructure supports the rapid development of China's new energy vehicle industry.It not only plays a decisive role in providing accessible and convenient services for electric vehicle(EV)users but also,in one of the seven new infrastructure areas,plays an important role in stabilizing growth and unleashing economic potential during the new coronavirus(COVID-19)pandemic,impacting China's economy.In this study,the system dynamics model was used to predict the development of the EV industry and the demand for charging infrastructure,while considering the influence of policy,increase in EV mileage,and consumer purchase intention index.Furthermore,using the matching of EVs and charging infrastructure in Beijing and policy oriented sensitivity analysis,a simulation of the construction of battery swap taxis and power stations under three policy scenarios was conducted.This research shows that with policies implemented to support charging infrastructure and swapping compatible taxis,Beijing can achieve its goal of replacing all EVs with fast-swap batteries and fast-charging functions within three years.
基金This work was supported by the National Key R&D Program of China(No.2018YFB1701600).
文摘In order to obtain stable and high-precision motion tracking in mixed reality(MR)simulation of the complex system,an optical-inertial hybrid tracking method is proposed,which combines the accuracy of optical motion capture equipment and the robustness of inertial motion capture equipment,and can reduce the occlusion problem of entity scene on the premise of ensuring the localization accuracy.The method has been applied to the ergonomic evaluation of large civil aircraft development processes,and the effectiveness and usability of the method have been verified.
基金This work was supported in part by the People Programme(Marie Curie Actions)of the European Union’s Seventh Framework Programme FP7/2007-2013/under REA grant agreement(No.317221)project title MEDOW,in part supported by the Project of National Science Foundation for Distinguished Young Scholars of China(No.51407164).
文摘With wider applications of power electronic devices in modern power systems,simulation using traditional electro-mechanical and electromagnetic simulation tools suffer from low speed and imprecision.Multi-rate technologies can greatly improve simulation efficiency by avoiding simulating the entire system using a small time-step.However,the drawbacks of the current synchronization mechanisms is that they introduce numerical errors and numerical instabilities in multi-rate parallel simulations.An improved multi-rate parallel technology,node splitting interface(NSI),is proposed to reduce errors and enhance simulation stability.A new synchronization mechanism is used to avoid prediction and signal delays.Theoretical analyses are carried out to prove the convergence and absolute stability of the proposed NSI algorithm.This algorithm is particularly suitable for simultaneously investigating long term dynamics of DC grids and fast transients of power electronic converters.
基金This work was supported by the National Science Fund for Distinguished Young Scholars(No.51325702)the China Postdoctoral Science Foundation(No.2014M560968).
文摘The energy conservation plays an important role for low carbon development.In order to evaluate the energy conservation in the full life-cycle,a scheme to estimate the energy consumption,or alternatively the energy pay,in constructing an overhead transmission line is proposed in this paper.The analysis of a typical projection is given for demonstration.With new additional overhead transmission lines,the energy consumption,known as the power loss in power network,is expected to be decline,which is defined in this paper as the energy payback.In order to estimate this kind of contribution,the scheme that consisted of load forecast,production simulation for generating systems,load flow simulation and power loss calculation has been proposed.Case studies,based on the IEEE 24-bus test system,are given to demonstrate the efficacy of the schemes.Moreover,several presumptive scenarios are deployed and analysed with the presented schemes for comparison.
基金supported by the Science and Technology Project of State Grid Corporation“Research on Key Technologies of Power Artificial Intelligence Open Platform” (5700-202155260A-0-0-00).
文摘The edge computing model enables real-time and low-power processing of data,while contributing to data security and privacy protection.However,the heterogeneity and diversity of edge computing devices pose a great challenge to task scheduling and migration.Most of the existing studies only consider the allocation of computational resources,but lack comprehensive consideration of data resources,storage space,etc.In this paper,we proposed intelligent scheduling strategies for computing power resources in heterogeneous edge networks.We define the relevant models and construct a comprehensive matching matrix in terms of task matching with computing resources,data resources,storage resources,load balancing of computing devices and storage space matching,and design an intelligent scheduling algorithm based on iteration and load balancing according to the matching degree of tasks and computing devices in the heterogeneous edge network environment.The iterative and load-balanced scheduling algorithm is based on the least-cost flow solution scheduling strategy,which effectively reduces the task computation response time and improves the computation and storage resource utilization of computing devices.Experimental validation of the proposed intelligent scheduling strategy is carried out based on a simulation environment.The experimental results show that the proposed intelligent scheduling strategy has obvious advantages over random scheduling methods in terms of task processing delay,computing power resource utilization and number of satisfactory tasks.
