This article focuses on electric power engineering and expounds the development characteristics and applications of new electric power engineering technologies,including technologies such as smart grids and digital de...This article focuses on electric power engineering and expounds the development characteristics and applications of new electric power engineering technologies,including technologies such as smart grids and digital design platforms.It explores the identification and classification of risk elements in electric power engineering and analyzes the deficiencies of traditional risk assessment methods.It introduces the applications of new technologies such as intelligent sensor networks in risk management,proposes a dual-driven model of technology and management,and looks forward to the application prospects of artificial intelligence and blockchain technologies.展开更多
In the field of electric power engineering,due to technological innovation,the evolution of smart grid technology and the access to new energy have changed the system structure,and the characteristics of risks have al...In the field of electric power engineering,due to technological innovation,the evolution of smart grid technology and the access to new energy have changed the system structure,and the characteristics of risks have also evolved.Traditional risk assessment methods and organizational structures are facing challenges.Emerging technologies such as big data and digital twins are applied to risk management.The new paradigm requires the reconstruction of organizational structures and collaborative governance,and involves the construction of a standardized system and ethical norms.展开更多
Driven by both the“new engineering”initiative and the energy revolution,the traditional engineering education model can hardly meet the demand of the energy and electric power industry for diversified and interdisci...Driven by both the“new engineering”initiative and the energy revolution,the traditional engineering education model can hardly meet the demand of the energy and electric power industry for diversified and interdisciplinary outstanding engineers.Based on the“industry-university-research-application”four-in-one collaborative education concept,this paper constructs a new training system centered on classified cultivation and classified evaluation.The system aims to solve core problems such as homogeneous training,disconnection between industry and academia,single evaluation method,and insufficient faculty.Through measures including modular courses,the dual-tutor system,and diversified practical platforms,it realizes differentiated and precise talent training,so as to deliver outstanding engineers with the ability to“define problems,break through technologies,and create value”for the energy and electric power industry.展开更多
With the acceleration of the intelligent transformation of power systems,the requirements for communication technology are increasingly stringent.The application of 5G mobile communication technology in power communic...With the acceleration of the intelligent transformation of power systems,the requirements for communication technology are increasingly stringent.The application of 5G mobile communication technology in power communication is analyzed.In this study,5G technology features,application principles,and practical strategies are discussed,and methods such as network slicing,customized deployment,edge computing collaborative application,communication equipment integration and upgrading,and multi-technology collaboration and complementation are proposed.It aims to effectively improve the efficiency,reliability,and security of power communication,solve the problem that traditional communication technology is difficult to meet the diversified needs of power business,and achieve the effect of optimizing the power communication network and supporting the intelligent development of the power system.展开更多
On the world's highest plateau,a sixty-year energy revolution has quietly reshaped this ancient land.As night falls,the lights of the Barkhor Street in Lhasa flicker on one after another,while in the depths of the...On the world's highest plateau,a sixty-year energy revolution has quietly reshaped this ancient land.As night falls,the lights of the Barkhor Street in Lhasa flicker on one after another,while in the depths of the Changtang grasslands,herding families watch the evening news on their televisions.Behind these ordinary scenes lies the extraordinary journey of Xizang's electric power industry-from nothing to existence,from weakness to strength.展开更多
As a matured technique used in many fields,the distributed computer system is still a new management method for the aeronautical electrical power distribution system in our country. In this paper, a novel aircraft ele...As a matured technique used in many fields,the distributed computer system is still a new management method for the aeronautical electrical power distribution system in our country. In this paper, a novel aircraft electrical power distribution system based on the distributed computer system is proposed. The principles, features and structure of the aircraft electrical power distribution system and the distributed computer system named electrical load management system (ELMS) are studied. The ELMS composed of four electrical load management centers (ELMCs) and two power source processors (PSPs) operates in the 1553B buses. Principles of the ELMCs and the PSPs are introduced. With the application of the distributed computer system, the aircraft electrical power distribution system is simple, adaptable and flexible.展开更多
The dynanaic model of a novel electric power steering（EPS） system integrated with active front steer- ing function and the three-freedom steering model are built. Based on these models, the concepts and the quanti- ...The dynanaic model of a novel electric power steering（EPS） system integrated with active front steer- ing function and the three-freedom steering model are built. Based on these models, the concepts and the quanti- tative expressions of road feel, sensitivity, and operation stability of the steering are introduced. Then, according to constrained optimization features of multi-variable function, a genetic algorithm is designed. Making the road feel of the steering as optimization objective, and operation stability and sensitivity of the steering as constraints, the system parameters are optimized by the genetic and the coordinate rotation algorithms. Simulation results show that the optimization of the novel EPS system by the genetic algorithm can effectively improve the road feel, thus providing a theoretical basis for the design and optimization of the novel EPS system.展开更多
Aiming at the comparatively laggard level of power plant electrical system automation, this paper analyzes the feasibility,necessity and some key points of the application of integrated automation technology to power ...Aiming at the comparatively laggard level of power plant electrical system automation, this paper analyzes the feasibility,necessity and some key points of the application of integrated automation technology to power plant electrical system. New idea using fieldbus control system technology is presented. This paper also gives the outline and detailed schemes.展开更多
This paper presents the study and application of the electronic device anti-interference techniques underhigh voltage and/or heavy current electro-magnetic circumstance in power system.[
This paper discusses the potential and prospect of building-integrated photovoltaics (BIPV) for solar electrical power generation in China.The BIPV technology has been identified as the most economical renewable energ...This paper discusses the potential and prospect of building-integrated photovoltaics (BIPV) for solar electrical power generation in China.The BIPV technology has been identified as the most economical renewable energy resource to contribute to world electrical energy demand for protecting environment from reduced fossil fuel consumption.The available solar energy resource of 14 cities and the potential power generation from PV claddings in buildings in China were estimated.The economical analysis of BIPV application is discussed.It is found that the potential is significant and the government should play an important role in its development.展开更多
A kind of algorithm was provided to resolve the calculating problem of stochastic frontier model and applied to electric power industry.By Matlab,maximum likelihood estimation is adopted to evaluate σ and λ of stoch...A kind of algorithm was provided to resolve the calculating problem of stochastic frontier model and applied to electric power industry.By Matlab,maximum likelihood estimation is adopted to evaluate σ and λ of stochastic frontier model in this paper, then the technical efficiency of electric power companies is calculated. The calculated and analyzed results reflect the situation of the management of electric power industry on the whole,that is ,the electric power companies with high technical efficiency are those which have developed their modern enterprise system successfully.展开更多
This paper briefs the development policies and focal construction points of powerindustry in China in 10th Five-year Plan period, and in accordance with the developmentaltrends of international power technology, puts ...This paper briefs the development policies and focal construction points of powerindustry in China in 10th Five-year Plan period, and in accordance with the developmentaltrends of international power technology, puts forward the key technological problems tobe studies in China power industry currently.[展开更多
The tracking performance of motor current is an important factor that affects the assistance torque of electric power steering （EPS） system. Bad tracking performance will cause assistant torque delay, and make road ...The tracking performance of motor current is an important factor that affects the assistance torque of electric power steering （EPS） system. Bad tracking performance will cause assistant torque delay, and make road feeling bad, and is influenced by the input steering torque and system measuring noise. However the existing methods have some shortages on system＇s robust dynamic performance and robust stability. The mixed H2/H∞ strategy for recirculating ball-type EPS system in a pure electric bus is proposed, and vehicle dynamic model of the system is established. Due to the existence of system model uncertainty, disturbance signals, sensor noises and the demand of system dynamic performance, the indexes of robust performance and road feeling for drivers are defined as the appraisal control objectives. The H∞ method is introduced to design the H∞ controller, and the H2 method is applied to optimize the H∞ controller, thus the mixed H2/H∞ controller is designed. The response of EPS system to the motor current command with amplitude of 20 A, the road disturbance with amplitude of 500 N and the sensor random noise with the amplitude of 1 A is simulated. The simulation results show that the recirculating ball-type EPS system with the mixed H2/H∞ controller can attenuate the random noises and disturbances and track the boost curve well, so the mixed H2/H∞ controller can improve the system＇s robust performance and dynamic performance. For the purpose of verifying the performance of the designed control strategy, the motor current tracking performance ground tests are conducted with step response input of the steering wheel, double-lane steering test and lemniscate steering test, respectively. The tests show that the mixed H2/H∞ controller for the recirculating ball-type EPS system of pure electric bus is feasible. The designed controller can solve the robust performance and robust stability of the system, thus improve the tracking performance of the EPS system and provide satisfied road feeling for the drivers.展开更多
Based on the traditional active steering system, a novel active steering system integrated with electric power steering function was introduced, which can achieve the functions of both active steering and electric pow...Based on the traditional active steering system, a novel active steering system integrated with electric power steering function was introduced, which can achieve the functions of both active steering and electric power steering. In view of the interference from road random signal and sensor noise in the novel active steering system, the H∞ control model of the novel active steering system was built. With satisfying steering feel, good robust performance and steering stability being the control objectives, the H∞ controller for the novel active front steering (AFS) system was designed. The simulation results show that the novel AFS system with H∞ control strategy can attenuate the road interference quickly, and there is no resonance peak in the bode diagram. It can make the driver obtain more useful information in the low frequency range, and attenuate the road interference better in the high frequency range, thus the driver can get more satisfying road feeling. Therefore, the designed H∞ controller can synthesize the advantages of both robust performance and robust stability, and has certain contribution to the design of novel AFS system.展开更多
Electric power consumption(EPC)is one of the basic indices for evaluating electric power use.Obtaining timely and accurate data on the spatiotemporal dynamics of EPC is crucial for understanding and practical deployme...Electric power consumption(EPC)is one of the basic indices for evaluating electric power use.Obtaining timely and accurate data on the spatiotemporal dynamics of EPC is crucial for understanding and practical deployment of electric power resources.In this study,an EPC model was developed using stable nighttime lights time-series data from the Defense Meteorological Satellite Program Operational Linescan System(DMSP/OLS).The model was used to reconstruct the spatial patterns of EPC in Chinese Mainland at the county level from 1995 to 2008.In addition,the spatiotemporal dynamics of EPC were analyzed,and the fol-lowing conclusions were drawn.(1)The EPC model reliably represented the spatiotemporal dynamics of EPC in Chinese Mainland with approximately 70%accuracy.(2)The EPC in most regions of Chinese Mainland was at low to moderate levels,with marked temporal and spatial variations;of high-level EPC,58.26%was concentrated in eastern China.Six urban agglomerations(Beijing-Tianjin-Tangshan region,Shanghai-Nanjing-Hangzhou region,Pearl River Delta,Shandong Peninsula,middle-south of Liaoning Province,and Sichuan Basin)accounted for 10.69%of the total area of Chinese Mainland but consumed 39.23%of the electricity.(3)The EPC of most regions in Chinese Mainland increased from 1995 to 2008,and 64%of the mainland area showed a significant increase in EPC.Moderate increases in EPC were found in 61.62%of eastern China and 80.65%of central China from 1995 to 2008,whereas 75.69%of western China showed no significant increase in EPC.Meanwhile,77.27%,89.35%,and 66.72%of the Shanghai-Nanjing-Hangzhou region,Pearl River Delta,and Shandong Peninsula,respectively,showed high-speed increases in EPC.Moderate increases in EPC occurred in 71.12%and 72.13%of the Beijing-Tianjin-Tangshan region and middle-south of Liaoning Province,respectively,while no significant increase occurred in 56.34%of the Sichuan Basin.展开更多
The dynamic model of a novel electric power steering （EPS） system integrated with active front steering function （the novel EPS system） is built. The concepts and quantitative expressions of the steering road feel...The dynamic model of a novel electric power steering （EPS） system integrated with active front steering function （the novel EPS system） is built. The concepts and quantitative expressions of the steering road feel, steering sensibility, and steering operation stability are introduced. Based on quality engineering theory, the optimization algorithm is proposed by integrating the Monte Carlo descriptive sampling, elitist non-dominated sorting genetic algorithm （NSGA-II） and 6-sigma design method. With the steering road feel and the steering portability as optimization targets, the system parameters are optimized by the proposed optimization algorithm. The simulation results show that the system optimized based on quality engineering theory can improve the steering road feel, guarantee steering stability and steering portability and thus provide a theoretical basis for the design and optimization of the novel electric power steering system.展开更多
To design a power source system and mold for electromagnetic soft-contact continuous casting process and to theoretically estimate the heat losses from the charges and the system power, the effect of structure paramet...To design a power source system and mold for electromagnetic soft-contact continuous casting process and to theoretically estimate the heat losses from the charges and the system power, the effect of structure parameters on system power and magnetic flux density distribution was calculated using finite element method. The results show that as for electromagnetic soft-contact continuous casting system with partial-segment type mold, the power consumption is much more than that with a full-segment type mold; about 62% of electric power is dissipated in the mold, and the effective acting range of magnetic field is relatively narrow. Optimizing mold structure is a crucial measure of remarkably reducing mold power consumption and saving electric energy. Increasing slit number, width, and length can remarkably increase the magnetic flux density in the mold and can reduce the electric energy consumption. Among structure parameters, slit number and slit width are relatively more effective to reduce energy consumption. For a round billet electromagnetic continuous casting system with diameter of 178 ram, the reasonable slit number, width, and length are about 24--32, 0. 5--1.0 mm, and 160 mm, respectively.展开更多
China＇s energy carbon emissions are projected to peak in 2030 with approximately 110% of its 2020 level under the following conditions： 1） China＇s gross primary energy consumption is 5 Gtce in 2020 and 6 Gtce in 2...China＇s energy carbon emissions are projected to peak in 2030 with approximately 110% of its 2020 level under the following conditions： 1） China＇s gross primary energy consumption is 5 Gtce in 2020 and 6 Gtce in 2030; 2） coal＇s share of the energy consumption is 61% in 2020 and 55% in 2030; 3） non-fossil energy＇s share increases from 15% in 2020 to 20% in 2030; 4） through 2030, China＇s GDP grows at an average annual rate of 6%; 5） the annual energy consumption elasticity coefficient is 0.30 in average; and 6） the annual growth rate of energy consumption steadily reduces to within 1%. China＇s electricity generating capacity would be 1,990 GW, with 8,600 TW h of power generation output in 2020. Of that output 66% would be from coal, 5% from gas, and 29% from non-fossil energy. By 2030, electricity generating capacity would reach 3,170 GW with 11,900 TW h of power generation output. Of that output, 56% would be from coal, 6% from gas, and 37% from non-fossil energy. From 2020 to 2030, CO2 emissions from electric power would relatively fall by 0.2 Gt due to lower coal consumption, and rela- tively fall by nearly 0.3 Gt with the installation of more coal-fired cogeneration units. During 2020--2030, the portion of carbon emissions from electric power in China＇s energy consumption is projected to increase by 3.4 percentage points. Although the carbon emissions from electric power would keep increasing to 118% of the 2020 level in 2030, the electric power industry would continue to play a decisive role in achieving the goal of increase in non-fossil energy use. This study proposes countermeasures and recommendations to control carbon emissions peak, including energy system optimization, green-coal-fired electricity generation, and demand side management.展开更多
Based on the De.Morgan laws and Boolean simplification, a recursive decomposition method is introduced in this paper to identify the main exclusive safe paths and failed paths of a network. The reliability or the reli...Based on the De.Morgan laws and Boolean simplification, a recursive decomposition method is introduced in this paper to identify the main exclusive safe paths and failed paths of a network. The reliability or the reliability bound of a network can be conveniently expressed as the summation of the joint probabilities of these paths. Under the multivariate normal distribution assumption, a conditioned reliability index method is developed to evaluate joint probabilities of various exclusive safe paths and failed paths, and, finally, the seismic reliability or the reliability bound of an electric power system. Examples given in the paper show that the method is very simple and provides accurate results in the seismic reliability analysis.展开更多
文摘This article focuses on electric power engineering and expounds the development characteristics and applications of new electric power engineering technologies,including technologies such as smart grids and digital design platforms.It explores the identification and classification of risk elements in electric power engineering and analyzes the deficiencies of traditional risk assessment methods.It introduces the applications of new technologies such as intelligent sensor networks in risk management,proposes a dual-driven model of technology and management,and looks forward to the application prospects of artificial intelligence and blockchain technologies.
文摘In the field of electric power engineering,due to technological innovation,the evolution of smart grid technology and the access to new energy have changed the system structure,and the characteristics of risks have also evolved.Traditional risk assessment methods and organizational structures are facing challenges.Emerging technologies such as big data and digital twins are applied to risk management.The new paradigm requires the reconstruction of organizational structures and collaborative governance,and involves the construction of a standardized system and ethical norms.
文摘Driven by both the“new engineering”initiative and the energy revolution,the traditional engineering education model can hardly meet the demand of the energy and electric power industry for diversified and interdisciplinary outstanding engineers.Based on the“industry-university-research-application”four-in-one collaborative education concept,this paper constructs a new training system centered on classified cultivation and classified evaluation.The system aims to solve core problems such as homogeneous training,disconnection between industry and academia,single evaluation method,and insufficient faculty.Through measures including modular courses,the dual-tutor system,and diversified practical platforms,it realizes differentiated and precise talent training,so as to deliver outstanding engineers with the ability to“define problems,break through technologies,and create value”for the energy and electric power industry.
文摘With the acceleration of the intelligent transformation of power systems,the requirements for communication technology are increasingly stringent.The application of 5G mobile communication technology in power communication is analyzed.In this study,5G technology features,application principles,and practical strategies are discussed,and methods such as network slicing,customized deployment,edge computing collaborative application,communication equipment integration and upgrading,and multi-technology collaboration and complementation are proposed.It aims to effectively improve the efficiency,reliability,and security of power communication,solve the problem that traditional communication technology is difficult to meet the diversified needs of power business,and achieve the effect of optimizing the power communication network and supporting the intelligent development of the power system.
文摘On the world's highest plateau,a sixty-year energy revolution has quietly reshaped this ancient land.As night falls,the lights of the Barkhor Street in Lhasa flicker on one after another,while in the depths of the Changtang grasslands,herding families watch the evening news on their televisions.Behind these ordinary scenes lies the extraordinary journey of Xizang's electric power industry-from nothing to existence,from weakness to strength.
文摘As a matured technique used in many fields,the distributed computer system is still a new management method for the aeronautical electrical power distribution system in our country. In this paper, a novel aircraft electrical power distribution system based on the distributed computer system is proposed. The principles, features and structure of the aircraft electrical power distribution system and the distributed computer system named electrical load management system (ELMS) are studied. The ELMS composed of four electrical load management centers (ELMCs) and two power source processors (PSPs) operates in the 1553B buses. Principles of the ELMCs and the PSPs are introduced. With the application of the distributed computer system, the aircraft electrical power distribution system is simple, adaptable and flexible.
基金Supported by the National Natural Science Foundation of China(51005115)the Risiting Scholar Foundation of the State Key Lab of Mechanical Transmission in Chongqing University(SKLMT-KFKT-201105)theScience Fund of State Key Laboratory of Automotive Satefy and Energy in Tsinghua University(KF11202)~~
文摘The dynanaic model of a novel electric power steering（EPS） system integrated with active front steer- ing function and the three-freedom steering model are built. Based on these models, the concepts and the quanti- tative expressions of road feel, sensitivity, and operation stability of the steering are introduced. Then, according to constrained optimization features of multi-variable function, a genetic algorithm is designed. Making the road feel of the steering as optimization objective, and operation stability and sensitivity of the steering as constraints, the system parameters are optimized by the genetic and the coordinate rotation algorithms. Simulation results show that the optimization of the novel EPS system by the genetic algorithm can effectively improve the road feel, thus providing a theoretical basis for the design and optimization of the novel EPS system.
文摘Aiming at the comparatively laggard level of power plant electrical system automation, this paper analyzes the feasibility,necessity and some key points of the application of integrated automation technology to power plant electrical system. New idea using fieldbus control system technology is presented. This paper also gives the outline and detailed schemes.
文摘This paper presents the study and application of the electronic device anti-interference techniques underhigh voltage and/or heavy current electro-magnetic circumstance in power system.[
文摘This paper discusses the potential and prospect of building-integrated photovoltaics (BIPV) for solar electrical power generation in China.The BIPV technology has been identified as the most economical renewable energy resource to contribute to world electrical energy demand for protecting environment from reduced fossil fuel consumption.The available solar energy resource of 14 cities and the potential power generation from PV claddings in buildings in China were estimated.The economical analysis of BIPV application is discussed.It is found that the potential is significant and the government should play an important role in its development.
文摘A kind of algorithm was provided to resolve the calculating problem of stochastic frontier model and applied to electric power industry.By Matlab,maximum likelihood estimation is adopted to evaluate σ and λ of stochastic frontier model in this paper, then the technical efficiency of electric power companies is calculated. The calculated and analyzed results reflect the situation of the management of electric power industry on the whole,that is ,the electric power companies with high technical efficiency are those which have developed their modern enterprise system successfully.
文摘This paper briefs the development policies and focal construction points of powerindustry in China in 10th Five-year Plan period, and in accordance with the developmentaltrends of international power technology, puts forward the key technological problems tobe studies in China power industry currently.[
基金supported by National Natural Science Foundation of China (Grant No. 51005115, No. 51005248)Science Fund of State Key Laboratory of Automotive Safety and Energy of China (Grant No. KF11201)
文摘The tracking performance of motor current is an important factor that affects the assistance torque of electric power steering （EPS） system. Bad tracking performance will cause assistant torque delay, and make road feeling bad, and is influenced by the input steering torque and system measuring noise. However the existing methods have some shortages on system＇s robust dynamic performance and robust stability. The mixed H2/H∞ strategy for recirculating ball-type EPS system in a pure electric bus is proposed, and vehicle dynamic model of the system is established. Due to the existence of system model uncertainty, disturbance signals, sensor noises and the demand of system dynamic performance, the indexes of robust performance and road feeling for drivers are defined as the appraisal control objectives. The H∞ method is introduced to design the H∞ controller, and the H2 method is applied to optimize the H∞ controller, thus the mixed H2/H∞ controller is designed. The response of EPS system to the motor current command with amplitude of 20 A, the road disturbance with amplitude of 500 N and the sensor random noise with the amplitude of 1 A is simulated. The simulation results show that the recirculating ball-type EPS system with the mixed H2/H∞ controller can attenuate the random noises and disturbances and track the boost curve well, so the mixed H2/H∞ controller can improve the system＇s robust performance and dynamic performance. For the purpose of verifying the performance of the designed control strategy, the motor current tracking performance ground tests are conducted with step response input of the steering wheel, double-lane steering test and lemniscate steering test, respectively. The tests show that the mixed H2/H∞ controller for the recirculating ball-type EPS system of pure electric bus is feasible. The designed controller can solve the robust performance and robust stability of the system, thus improve the tracking performance of the EPS system and provide satisfied road feeling for the drivers.
基金Foundation item： Projects（51005115, 51205191） supported by the National Natural Science Foundation of China Project（2012-NELEV-03） supported by the Research Foundation of National Engineering Laboratory for Electric Vehicles, China+2 种基金 Project（kfjj 120105） supported by the Visiting Scholar Foundation of the State Key Laboratory of Mechanical Transmission in Chongqing University, China Project supported by the Funds from the Postgraduate Creative Base in Nanjing University of Areonautics and Astronautics, China Project supported by the Fundamental Research Funds for the Central Universities, China
文摘Based on the traditional active steering system, a novel active steering system integrated with electric power steering function was introduced, which can achieve the functions of both active steering and electric power steering. In view of the interference from road random signal and sensor noise in the novel active steering system, the H∞ control model of the novel active steering system was built. With satisfying steering feel, good robust performance and steering stability being the control objectives, the H∞ controller for the novel active front steering (AFS) system was designed. The simulation results show that the novel AFS system with H∞ control strategy can attenuate the road interference quickly, and there is no resonance peak in the bode diagram. It can make the driver obtain more useful information in the low frequency range, and attenuate the road interference better in the high frequency range, thus the driver can get more satisfying road feeling. Therefore, the designed H∞ controller can synthesize the advantages of both robust performance and robust stability, and has certain contribution to the design of novel AFS system.
基金The National Basic Research Program of China,No.2010CB950901National Natural Science Foundation of China,No.40971059
文摘Electric power consumption(EPC)is one of the basic indices for evaluating electric power use.Obtaining timely and accurate data on the spatiotemporal dynamics of EPC is crucial for understanding and practical deployment of electric power resources.In this study,an EPC model was developed using stable nighttime lights time-series data from the Defense Meteorological Satellite Program Operational Linescan System(DMSP/OLS).The model was used to reconstruct the spatial patterns of EPC in Chinese Mainland at the county level from 1995 to 2008.In addition,the spatiotemporal dynamics of EPC were analyzed,and the fol-lowing conclusions were drawn.(1)The EPC model reliably represented the spatiotemporal dynamics of EPC in Chinese Mainland with approximately 70%accuracy.(2)The EPC in most regions of Chinese Mainland was at low to moderate levels,with marked temporal and spatial variations;of high-level EPC,58.26%was concentrated in eastern China.Six urban agglomerations(Beijing-Tianjin-Tangshan region,Shanghai-Nanjing-Hangzhou region,Pearl River Delta,Shandong Peninsula,middle-south of Liaoning Province,and Sichuan Basin)accounted for 10.69%of the total area of Chinese Mainland but consumed 39.23%of the electricity.(3)The EPC of most regions in Chinese Mainland increased from 1995 to 2008,and 64%of the mainland area showed a significant increase in EPC.Moderate increases in EPC were found in 61.62%of eastern China and 80.65%of central China from 1995 to 2008,whereas 75.69%of western China showed no significant increase in EPC.Meanwhile,77.27%,89.35%,and 66.72%of the Shanghai-Nanjing-Hangzhou region,Pearl River Delta,and Shandong Peninsula,respectively,showed high-speed increases in EPC.Moderate increases in EPC occurred in 71.12%and 72.13%of the Beijing-Tianjin-Tangshan region and middle-south of Liaoning Province,respectively,while no significant increase occurred in 56.34%of the Sichuan Basin.
基金Projects(51005115,51205191)supported by the National Natural Science Foundation of ChinaProject(QC201101)supported by the Visiting Scholar Foundation of the Automobile Engineering Key Laboratory of Jiangsu Province,China+1 种基金Project(SKLMT-KFKT-201105)supported by the Visiting Scholar Foundation of the State Key Laboratory of Mechanical Transmission in Chongqing University,ChinaProjects(NS2013015,NS2012086)supported by the Funds from the Postgraduate Creative Base in Nanjing University of Areonautics and Astronautics,and NUAA Research Funding,China
文摘The dynamic model of a novel electric power steering （EPS） system integrated with active front steering function （the novel EPS system） is built. The concepts and quantitative expressions of the steering road feel, steering sensibility, and steering operation stability are introduced. Based on quality engineering theory, the optimization algorithm is proposed by integrating the Monte Carlo descriptive sampling, elitist non-dominated sorting genetic algorithm （NSGA-II） and 6-sigma design method. With the steering road feel and the steering portability as optimization targets, the system parameters are optimized by the proposed optimization algorithm. The simulation results show that the system optimized based on quality engineering theory can improve the steering road feel, guarantee steering stability and steering portability and thus provide a theoretical basis for the design and optimization of the novel electric power steering system.
基金supported by National Natural Science Foundation of China(61273108)the Fundamental Research Funds for the Central Universities(106112013CDJZR175501)the Scientific Research Foundation for the Returned Overseas Chinese Scholars,State Education Ministry
基金Item Sponsored by National Natural Science Foundation of China(50274203)National High Technology Research and Development Program of China(2001AA337040)
文摘To design a power source system and mold for electromagnetic soft-contact continuous casting process and to theoretically estimate the heat losses from the charges and the system power, the effect of structure parameters on system power and magnetic flux density distribution was calculated using finite element method. The results show that as for electromagnetic soft-contact continuous casting system with partial-segment type mold, the power consumption is much more than that with a full-segment type mold; about 62% of electric power is dissipated in the mold, and the effective acting range of magnetic field is relatively narrow. Optimizing mold structure is a crucial measure of remarkably reducing mold power consumption and saving electric energy. Increasing slit number, width, and length can remarkably increase the magnetic flux density in the mold and can reduce the electric energy consumption. Among structure parameters, slit number and slit width are relatively more effective to reduce energy consumption. For a round billet electromagnetic continuous casting system with diameter of 178 ram, the reasonable slit number, width, and length are about 24--32, 0. 5--1.0 mm, and 160 mm, respectively.
文摘China＇s energy carbon emissions are projected to peak in 2030 with approximately 110% of its 2020 level under the following conditions： 1） China＇s gross primary energy consumption is 5 Gtce in 2020 and 6 Gtce in 2030; 2） coal＇s share of the energy consumption is 61% in 2020 and 55% in 2030; 3） non-fossil energy＇s share increases from 15% in 2020 to 20% in 2030; 4） through 2030, China＇s GDP grows at an average annual rate of 6%; 5） the annual energy consumption elasticity coefficient is 0.30 in average; and 6） the annual growth rate of energy consumption steadily reduces to within 1%. China＇s electricity generating capacity would be 1,990 GW, with 8,600 TW h of power generation output in 2020. Of that output 66% would be from coal, 5% from gas, and 29% from non-fossil energy. By 2030, electricity generating capacity would reach 3,170 GW with 11,900 TW h of power generation output. Of that output, 56% would be from coal, 6% from gas, and 37% from non-fossil energy. From 2020 to 2030, CO2 emissions from electric power would relatively fall by 0.2 Gt due to lower coal consumption, and rela- tively fall by nearly 0.3 Gt with the installation of more coal-fired cogeneration units. During 2020--2030, the portion of carbon emissions from electric power in China＇s energy consumption is projected to increase by 3.4 percentage points. Although the carbon emissions from electric power would keep increasing to 118% of the 2020 level in 2030, the electric power industry would continue to play a decisive role in achieving the goal of increase in non-fossil energy use. This study proposes countermeasures and recommendations to control carbon emissions peak, including energy system optimization, green-coal-fired electricity generation, and demand side management.
基金National Outstanding Youth Science Foundation of China Under Grant No.598251005
文摘Based on the De.Morgan laws and Boolean simplification, a recursive decomposition method is introduced in this paper to identify the main exclusive safe paths and failed paths of a network. The reliability or the reliability bound of a network can be conveniently expressed as the summation of the joint probabilities of these paths. Under the multivariate normal distribution assumption, a conditioned reliability index method is developed to evaluate joint probabilities of various exclusive safe paths and failed paths, and, finally, the seismic reliability or the reliability bound of an electric power system. Examples given in the paper show that the method is very simple and provides accurate results in the seismic reliability analysis.
