PROOS is a distributed operating system running on the computing nodes of massively parallel processing computer Dawning-1000. It is an efficient and easily extendible micro kernel operating system. It supports the in...PROOS is a distributed operating system running on the computing nodes of massively parallel processing computer Dawning-1000. It is an efficient and easily extendible micro kernel operating system. It supports the intel NX message passing interface for communication.展开更多
The THUDSOS is a distributed operating system modeled as an abstract machine which provides de- centralized control,transparency,availability,and reliability,as well as a good degree of autonomy at each node,that make...The THUDSOS is a distributed operating system modeled as an abstract machine which provides de- centralized control,transparency,availability,and reliability,as well as a good degree of autonomy at each node,that makes our distributed system usable.Our operating system supports transparent access to data through network wide filesystem.The simultaneous access to any device is discussed for the case when the peripherals are treated as files.This operating system allows spawning of parallel applica- tion programs to solve problems in the fields,such as numerical analysis and artificial intelligence.展开更多
In this paper,the naming scheme used in the heterogeneous distributed operating system ZGL is described and some of the representative techniques utilized in current distributed operating systems are examined.It is be...In this paper,the naming scheme used in the heterogeneous distributed operating system ZGL is described and some of the representative techniques utilized in current distributed operating systems are examined.It is believed that the partitioning of the name space into many local name spaces and one global shared name space allows the ZGL system to satisfy each workstation's demand for local autono- my and still be able to facilitate transparent resource sharing.By the division of the system into clusters and the use of a combined centralized-distributed naming mechanism,the system is able to avoid both the bottleneck problem caused by a single centralized name server for the whole system and the per- formance degradation due to a full distributed scheme.展开更多
The paper describes international conflicts as complex confrontations where global actors clash over multiple,often overlapping,interests related to such areas and dimensions as security&military,economy&geopo...The paper describes international conflicts as complex confrontations where global actors clash over multiple,often overlapping,interests related to such areas and dimensions as security&military,economy&geopolitics,social&cultural,cyber&information and others,with reviewing different ideas and existing publications in them.It also briefs the developed Spatial Grasp Technology(SGT)and its Spatial Grasp Language(SGL)oriented on creation,investigation,and management or large distributed systems of different natures,while providing examples of SGL programming in both physical and virtual worlds.Main ideas and organization of the multidimensional management project,currently in the development,are discussed.An example of multidimensional conflict management using interacting physical,economic,transport,and virtual dimensions is provided in SGL with practical solutions covering four and three communicating dimensions.The planned further research in this area is outlined too.Different versions of SGT were successfully tested on numerous applications in different countries,and its latest version,especially suitable for multidimensional management,can be quickly implemented on any existing software or hardware platforms.展开更多
The increasing number of distributed energy resources connected to power systems raises operational challenges for the network operator, such as introducing grid congestion and voltage deviations in the distribution n...The increasing number of distributed energy resources connected to power systems raises operational challenges for the network operator, such as introducing grid congestion and voltage deviations in the distribution network level, as well as increasing balancing needs at the whole system level. Control and coordination of a large number of distributed energy assets requires innovative approaches. Transactive control has received much attention due to its decentralized decision-making and transparent characteristics. This paper introduces the concept and main features of transactive control, followed by a literature review and demonstration projects that apply to transactive control. Cases are then presented to illustrate the transactive control framework. At the end, discussions and research directions are presented, for applying transactive control to operating power systems, characterized by a high penetration of distributed energy resources.展开更多
Microgrids (MGs) and active distribution networks (ADNs) are important platforms for distributed energy resource (DER) consumption. The increasing penetration of DERs has motivated the development ADNs coupled with MG...Microgrids (MGs) and active distribution networks (ADNs) are important platforms for distributed energy resource (DER) consumption. The increasing penetration of DERs has motivated the development ADNs coupled with MGs. This paper proposes a distributedco-optimization method for peer-to-peer (P2P) energy trading and network operation for an ADN integrated with multiple microgrids(MMGs). A framework that optimizes P2P energy trading among MMGs and ADN operations was first established. Subsequently, anenergy management model that aims to minimize the operation and energy trading costs was constructed for each MG. Accordingly, theMMGs’ cooperative game model was established based on Nash bargaining theory to incentivize each stakeholder to participate in P2Penergy trading, and a distributed solution method based on the alternating direction method of multipliers was developed. Moreover, analgorithm that adjusts the amount of energy trading between the ADN and MG is proposed to ensure safe operation of the distributionnetwork. With the communication between the MG and ADN, the MMGs’ P2P trading and ADN operations are optimized in a coordinated manner. Finally, numerical simulations were conducted to verify the accuracy and effectiveness of the proposed method.展开更多
“Multidimensional international world”refers to understanding the world through multiple dimensions beyond traditional economic or political measures,fostering cross-cultural collaboration,and creating systems that ...“Multidimensional international world”refers to understanding the world through multiple dimensions beyond traditional economic or political measures,fostering cross-cultural collaboration,and creating systems that balance global integration with local needs.This also includes management of global business operations across diverse cultures in a multipolar international landscape.The paper briefs the developed and already tested in numerous applications high-level Spatial Grasp Model and Technology(SGT),which can help investigate and manage complex systems with a holistic spatial approach effectively covering various physical and virtual dimensions,their interrelations,and integration as a whole.Different areas will be investigated with examples of practical solutions in them and their combinations in a high-level Spatial Grasp Language(SGL),the key element of SGT.This allows for the creation and distributed management of very large spatial networks with different orientation which can be self-spreading,self-analyzing,self-modifying,and self-recovering in complex terrestrial and celestial environments,and also organize dynamic multi-networking solutions supporting global evolution and integrity.展开更多
“Multidimensional international world”refers to understanding the world through its multiple dimensions beyond traditional economic or political measures,by fostering cross-cultural collaboration and balancing globa...“Multidimensional international world”refers to understanding the world through its multiple dimensions beyond traditional economic or political measures,by fostering cross-cultural collaboration and balancing global integration with local needs.The paper briefs the developed high-level Spatial Grasp Model and Technology(SGT)which can investigate and manage complex systems with a holistic spatial approach effectively covering different physical and virtual dimensions and their integration as a whole.It then describes basics of multidimensional management system which is currently under development,and provides examples of practical solutions in different dimensions and their combinations in Spatial Grasp Language(SGL),the key element of SGT,with networking representations of the solutions.These include inter-dimensional influence and optimization,finding multidimensional communities,showing multidimensional recovery after disasters,finding dangerous multidimensional groupings,isolated multidimensional components,as well as interaction of physical and virtual dimensions.Different versions of SGT were tested on numerous applications and in different countries,and its latest version,especially suitable for multidimensional management,can be quickly implemented on any existing software or hardware platforms an integrated with advanced communication systems.展开更多
This paper presents a distributed operating system modeled as an abstract machine that provides all the distributed processes with the same set of services.The kernel of our operating system supports ser- vices which ...This paper presents a distributed operating system modeled as an abstract machine that provides all the distributed processes with the same set of services.The kernel of our operating system supports ser- vices which are achieved by a remote procedure call on requests by parallel processes.Therefore,a scheme for solving the client-server relationship is required.In our system there are more than one cli- ents and,at least,a receive would he required for each.Similarly,there are more than one servers such that the send in a client should produce a message that can he received by every server. Consequently,a mechanism well suited for programming multiple-clients/single-server and sin- gle client/multiple-servers interactions is proposed.展开更多
It is desirable in a distributed system to have the system load balanced evenly among the nodes so that the mean job response time is minimized. In this paper, we present.a dynamic load balancing mechanism (DLB). It a...It is desirable in a distributed system to have the system load balanced evenly among the nodes so that the mean job response time is minimized. In this paper, we present.a dynamic load balancing mechanism (DLB). It adopts a centralized approach and is network topology independent. The DLB mechanism employs a set of thresholds which are automatically adjusted as the system load changes. lt also provides a simple mechanism for the system to switch between periodic and instantaneous load balancing policies with ease. The performance of the proposed algorithm is evaluated by intensive simulations for various parameters. The simulAtion results show that the mean job response time in a system implementing DLB algorithm is significantly lower than the same system without load balancings. Furthermore, compared with a previously proposed algorithm, DLB algorithm demonstrates improved performance, especially when the system is heavily loaded and the load is unevenly distributed.展开更多
Measurement-device-independent quantum key distribution (MDI-QKD) is proven to be immune to all the de- tector side channel attacks. With two symmetric quantum channels, the maximal transmission distance can be doub...Measurement-device-independent quantum key distribution (MDI-QKD) is proven to be immune to all the de- tector side channel attacks. With two symmetric quantum channels, the maximal transmission distance can be doubled when compared with the prepare-and-measure QKD. An interesting question is whether the transmission distance can be extended further. In this work, we consider the contributions of the two-way local operations and classical communications to the key generation rate and transmission distance of the MDI-QKD. Our numerical results show that the secure transmission distances are increased by about 12kin and 8 km when the 1 13 and the 2 B steps are implemented, respectively.展开更多
Peer-to-peer(P2P)energy trading provides a promising solution for integrating distributed microgrids(MGs).However,most existing research works on P2P energy trading among MGs ignore the influence of the dynamic networ...Peer-to-peer(P2P)energy trading provides a promising solution for integrating distributed microgrids(MGs).However,most existing research works on P2P energy trading among MGs ignore the influence of the dynamic network usage fees imposed by the distribution system operator(DSO).Therefore,a method of P2P energy trading among MGs based on the optimal dynamic network usage fees is proposed in this paper to balance the benefits of DSO.The interaction between DSO and MG is formulated as a Stackelberg game,in which the existence and uniqueness of optimal dynamic network usage fees are proven.Additionally,the optimal dynamic network usage fees are obtained by transforming the bi-level problem into single-level mixed-integer quadratic programming using Karush-Kuhn-Tucker conditions.Furthermore,the underlying relationship among optimal dynamic network usage fees,electrical distance,and power flow is revealed,and the mechanism of the optimal dynamic network usage fee can further enhance P2P energy trading among MGs.Finally,simulation results on an enhanced IEEE 33-bus system demonstrate that the proposed mechanism achieves a 17.08%reduction in operation costs for MG while increasing DSO revenue by 15.36%.展开更多
The difficulty in capital recovery for distributed re newable energy operators(DREOs)and the high charging costs at electric vehicle charging stations(EVCSs)have long been sig nificant challenges in power systems.Coll...The difficulty in capital recovery for distributed re newable energy operators(DREOs)and the high charging costs at electric vehicle charging stations(EVCSs)have long been sig nificant challenges in power systems.Collaborative operation of DREOs and EVCSs can effectively address these challenges,yet few studies have approached incentivizing collaboration from the perspective of profit allocation.Therefore,this paper pro poses a fair and efficient profit allocation method.Incorporat ing the Gauss-Legendre quadrature formula into the AumannShapley value(GL-AS)method enables efficient calculation of the profit allocation of cooperative members.However,existing literature only discusses the profit allocation method of conven tional power generation units,limiting its applicability.This pa per addresses the problem of energy storage system(ESS)switching between charging and discharging in any time inter val and the time-varying problem of renewable energy power output,thereby ensuring the efficiency of the solution process.Furthermore,a novel profit allocation adjustment model is pro vided through the adoption of triangular fuzzy comprehensive evaluation(TFCE).Finally,the effectiveness of the proposed profit allocation method is validated through numerical simula tions in various scenarios.展开更多
It is to be expected that the number of electric vehicles will be growing in the near future. This trend comes together with the development of smaller decentralized generation units, like PV (photo voltaic). Togeth...It is to be expected that the number of electric vehicles will be growing in the near future. This trend comes together with the development of smaller decentralized generation units, like PV (photo voltaic). Together with the change on demand side that comes with the global "electrification", this can lead to serious grid congestion in low voltage grids and massive grid investments in solving this congestion. Smart charging can partly solve this issue, but with using a connected EV (electric vehicle) as a small distribution unit, combined with bi-directional charging or V2G (vehicle-to-grid) technology, these investments can be reduced to a minimum. In Lombok, Utrecht, the Netherlands, an innovative pilot was initiated with smart solar charging stations, shared electric vehicles and AC (alternating current) V2G technology. This unique combination proves that EVs are an opportunity for the grid rather than a threat. A unique partnership with OEM Renault was established to develop an AC V2G vehicle product line and work on open standardized communication between the EV, the charging station and the grid.展开更多
The main faults of distribution lines are divided into two types: faults caused by natural factors and faults caused by human factors. Natural factors are inevitable and unpredictable. When the weather forecast center...The main faults of distribution lines are divided into two types: faults caused by natural factors and faults caused by human factors. Natural factors are inevitable and unpredictable. When the weather forecast center issues a special disaster warning, the power company needs to make preparations in advance, equip maintenance personnel for areas that may suffer from power failure caused by lightning and storm, and take timely countermeasures in case of problems, so as to restore power supply as soon as possible and maintain the stability of social order. Faults caused by human factors can be avoided as far as possible, such as setting wires in places that people can't touch easily or providing police equipment slogans. Although man-made damage may still be caused in some cases, man-made factors are more avoidable than natural factors. Attention should also be paid to the situation that the staff of the power department do not consider carefully when erecting wires, which will directly lead to the damage of human factors. At the same time, it is also the basis for the existence of human induced fault factors.展开更多
At present, most of the problems existing in the operation and maintenance of power grid are related to power grid automation technology. If there are problems in the application of distribution automation technology,...At present, most of the problems existing in the operation and maintenance of power grid are related to power grid automation technology. If there are problems in the application of distribution automation technology, on the one hand, it will reduce the reliability of power grid, on the other hand, it will reduce the rapidity of power distribution. It can be seen that the distribution automation technology is very important for the normal operation and maintenance of power grid, and the relevant key in the application of distribution automation technology needs in-depth analysis and research.展开更多
With the rapid development of social economy, people's living standard is becoming higher and higher. As a national basic industry, power industry is of great significance to social development. China's power ...With the rapid development of social economy, people's living standard is becoming higher and higher. As a national basic industry, power industry is of great significance to social development. China's power enterprises mainly serve customers through distribution network, and the degree of automation of distribution network directly determines the reliability of power supply. At present, all kinds of science and technology are developing rapidly. Electric power enterprises should continuously improve the automation level of distribution network, effectively improve the reliability of power supply, maximize the efficiency of enterprise power distribution, meet the normal electricity demand of social residents, and promote the rapid development of social economy. Next, the article focuses on the application of distribution automation technology in distribution network operation and maintenance.展开更多
We report an index-coupled distributed feedback quantum cascade laser by employing an equivalent phase shift(EPS) of quarter-wave integrated with a distributed Bragg reflector(DBR) at λ~5.03 μm. The EPS is fabricate...We report an index-coupled distributed feedback quantum cascade laser by employing an equivalent phase shift(EPS) of quarter-wave integrated with a distributed Bragg reflector(DBR) at λ~5.03 μm. The EPS is fabricated through extending one sampling period by 50% in the center of a sampled Bragg grating. The key EPS and DBR pattern are fabricated by conventional holographic exposure combined with the optical photolithography technology, which leads to improved flexibility, repeatability, and cost-effectiveness. Stable single-mode emission can be obtained by changing the injection current or heat sink temperature even under the condition of large driving pulse width.展开更多
Distributed metadata consistency is one of the critical issues of metadata clusters in distributed file systems. Existing methods to maintain metadata consistency generally need several log forced write operations. Si...Distributed metadata consistency is one of the critical issues of metadata clusters in distributed file systems. Existing methods to maintain metadata consistency generally need several log forced write operations. Since synchronous disk IO is very inefficient, the average response time of metadata operations is greatly increased. In this paper, an asynchronous atomic commit protocol (ACP) named Dual-Log (DL) is presented. It does not need any log forced write operations. Optimizing for distributed metadata operations involving only two metadata servers, DL mutually records the redo log in counterpart metadata servers by transferring through the low latency network. A crashed metadata server can redo the metadata operation with the redundant redo log. Since the latency of the network is much lower than the latency of disk IO, DL can improve the performance of distributed metadata service significantly. The prototype of DL is implemented based on local journal. The performance is tested by comparing with two widely used protocols, EP and S2PC-MP, and the results show that the average response time of distributed metadata operations is reduced by about 40%-60%, and the recovery time is only I second under 10 thousands uncompleted distributed metadata operations.展开更多
Fault restoration techniques have always been crucial for distribution system operators(DSOs).In the last decade,it started to gain more and more importance due to the introduction of output-based regulations where DS...Fault restoration techniques have always been crucial for distribution system operators(DSOs).In the last decade,it started to gain more and more importance due to the introduction of output-based regulations where DSO performances are evaluated according to frequency and duration of energy supply interruptions.The paper presents a tabu-searchbased algorithm able to assist distribution network operational engineers in identifying solutions to restore the energy supply after permanent faults.According to the network property,two objective functions are considered to optimize either reliability or resiliency.The mathematical formulation includes the traditional feeders,number of switching operation limit,and radiality constraints.Thanks to the DSO of Milan,Unareti,the proposed algorithm has been tested on a real distribution network to investigate its effectiveness.展开更多
摘要PROOS is a distributed operating system running on the computing nodes of massively parallel processing computer Dawning-1000. It is an efficient and easily extendible micro kernel operating system. It supports the intel NX message passing interface for communication.
基金The project supported by National Natural Science Foundation of China.
摘要The THUDSOS is a distributed operating system modeled as an abstract machine which provides de- centralized control,transparency,availability,and reliability,as well as a good degree of autonomy at each node,that makes our distributed system usable.Our operating system supports transparent access to data through network wide filesystem.The simultaneous access to any device is discussed for the case when the peripherals are treated as files.This operating system allows spawning of parallel applica- tion programs to solve problems in the fields,such as numerical analysis and artificial intelligence.
摘要In this paper,the naming scheme used in the heterogeneous distributed operating system ZGL is described and some of the representative techniques utilized in current distributed operating systems are examined.It is believed that the partitioning of the name space into many local name spaces and one global shared name space allows the ZGL system to satisfy each workstation's demand for local autono- my and still be able to facilitate transparent resource sharing.By the division of the system into clusters and the use of a combined centralized-distributed naming mechanism,the system is able to avoid both the bottleneck problem caused by a single centralized name server for the whole system and the per- formance degradation due to a full distributed scheme.
摘要The paper describes international conflicts as complex confrontations where global actors clash over multiple,often overlapping,interests related to such areas and dimensions as security&military,economy&geopolitics,social&cultural,cyber&information and others,with reviewing different ideas and existing publications in them.It also briefs the developed Spatial Grasp Technology(SGT)and its Spatial Grasp Language(SGL)oriented on creation,investigation,and management or large distributed systems of different natures,while providing examples of SGL programming in both physical and virtual worlds.Main ideas and organization of the multidimensional management project,currently in the development,are discussed.An example of multidimensional conflict management using interacting physical,economic,transport,and virtual dimensions is provided in SGL with practical solutions covering four and three communicating dimensions.The planned further research in this area is outlined too.Different versions of SGT were successfully tested on numerous applications in different countries,and its latest version,especially suitable for multidimensional management,can be quickly implemented on any existing software or hardware platforms.
基金financed by the TNO Early Research Program on Energy Storage and Conversion(ERP ECS)through the SOSENS projectpartly supported by the Danish iPower project(http://gffzzf0b060c6984e4e24hqbpxfccoxv6b6qn9.ffgz.tsg.suse.edu.cn/)funded by the Danish Agency for Research and Innovation(No.0603-00435B)
摘要The increasing number of distributed energy resources connected to power systems raises operational challenges for the network operator, such as introducing grid congestion and voltage deviations in the distribution network level, as well as increasing balancing needs at the whole system level. Control and coordination of a large number of distributed energy assets requires innovative approaches. Transactive control has received much attention due to its decentralized decision-making and transparent characteristics. This paper introduces the concept and main features of transactive control, followed by a literature review and demonstration projects that apply to transactive control. Cases are then presented to illustrate the transactive control framework. At the end, discussions and research directions are presented, for applying transactive control to operating power systems, characterized by a high penetration of distributed energy resources.
基金supported by the State Key Laboratory of Technology and Equipment for Defense against Power System Operational Risks Program(grant number SGNR0000KJJS2302139).
摘要Microgrids (MGs) and active distribution networks (ADNs) are important platforms for distributed energy resource (DER) consumption. The increasing penetration of DERs has motivated the development ADNs coupled with MGs. This paper proposes a distributedco-optimization method for peer-to-peer (P2P) energy trading and network operation for an ADN integrated with multiple microgrids(MMGs). A framework that optimizes P2P energy trading among MMGs and ADN operations was first established. Subsequently, anenergy management model that aims to minimize the operation and energy trading costs was constructed for each MG. Accordingly, theMMGs’ cooperative game model was established based on Nash bargaining theory to incentivize each stakeholder to participate in P2Penergy trading, and a distributed solution method based on the alternating direction method of multipliers was developed. Moreover, analgorithm that adjusts the amount of energy trading between the ADN and MG is proposed to ensure safe operation of the distributionnetwork. With the communication between the MG and ADN, the MMGs’ P2P trading and ADN operations are optimized in a coordinated manner. Finally, numerical simulations were conducted to verify the accuracy and effectiveness of the proposed method.
摘要“Multidimensional international world”refers to understanding the world through multiple dimensions beyond traditional economic or political measures,fostering cross-cultural collaboration,and creating systems that balance global integration with local needs.This also includes management of global business operations across diverse cultures in a multipolar international landscape.The paper briefs the developed and already tested in numerous applications high-level Spatial Grasp Model and Technology(SGT),which can help investigate and manage complex systems with a holistic spatial approach effectively covering various physical and virtual dimensions,their interrelations,and integration as a whole.Different areas will be investigated with examples of practical solutions in them and their combinations in a high-level Spatial Grasp Language(SGL),the key element of SGT.This allows for the creation and distributed management of very large spatial networks with different orientation which can be self-spreading,self-analyzing,self-modifying,and self-recovering in complex terrestrial and celestial environments,and also organize dynamic multi-networking solutions supporting global evolution and integrity.
摘要“Multidimensional international world”refers to understanding the world through its multiple dimensions beyond traditional economic or political measures,by fostering cross-cultural collaboration and balancing global integration with local needs.The paper briefs the developed high-level Spatial Grasp Model and Technology(SGT)which can investigate and manage complex systems with a holistic spatial approach effectively covering different physical and virtual dimensions and their integration as a whole.It then describes basics of multidimensional management system which is currently under development,and provides examples of practical solutions in different dimensions and their combinations in Spatial Grasp Language(SGL),the key element of SGT,with networking representations of the solutions.These include inter-dimensional influence and optimization,finding multidimensional communities,showing multidimensional recovery after disasters,finding dangerous multidimensional groupings,isolated multidimensional components,as well as interaction of physical and virtual dimensions.Different versions of SGT were tested on numerous applications and in different countries,and its latest version,especially suitable for multidimensional management,can be quickly implemented on any existing software or hardware platforms an integrated with advanced communication systems.
基金The project supported by National Natural Science Foundation of China.
摘要This paper presents a distributed operating system modeled as an abstract machine that provides all the distributed processes with the same set of services.The kernel of our operating system supports ser- vices which are achieved by a remote procedure call on requests by parallel processes.Therefore,a scheme for solving the client-server relationship is required.In our system there are more than one cli- ents and,at least,a receive would he required for each.Similarly,there are more than one servers such that the send in a client should produce a message that can he received by every server. Consequently,a mechanism well suited for programming multiple-clients/single-server and sin- gle client/multiple-servers interactions is proposed.
摘要It is desirable in a distributed system to have the system load balanced evenly among the nodes so that the mean job response time is minimized. In this paper, we present.a dynamic load balancing mechanism (DLB). It adopts a centralized approach and is network topology independent. The DLB mechanism employs a set of thresholds which are automatically adjusted as the system load changes. lt also provides a simple mechanism for the system to switch between periodic and instantaneous load balancing policies with ease. The performance of the proposed algorithm is evaluated by intensive simulations for various parameters. The simulAtion results show that the mean job response time in a system implementing DLB algorithm is significantly lower than the same system without load balancings. Furthermore, compared with a previously proposed algorithm, DLB algorithm demonstrates improved performance, especially when the system is heavily loaded and the load is unevenly distributed.
基金Supported by the National Natural Science Foundation of China under Grant No 61378011the Program for Science and Technology Innovation Research Team in University of Henan Province under Grant No 13IRTSTHN020
摘要Measurement-device-independent quantum key distribution (MDI-QKD) is proven to be immune to all the de- tector side channel attacks. With two symmetric quantum channels, the maximal transmission distance can be doubled when compared with the prepare-and-measure QKD. An interesting question is whether the transmission distance can be extended further. In this work, we consider the contributions of the two-way local operations and classical communications to the key generation rate and transmission distance of the MDI-QKD. Our numerical results show that the secure transmission distances are increased by about 12kin and 8 km when the 1 13 and the 2 B steps are implemented, respectively.
基金supported by the National Natural Science Foundation of China(No.52107199)the International Corporation Project of Shanghai Science and Technology Commission(No.21190780300).
摘要Peer-to-peer(P2P)energy trading provides a promising solution for integrating distributed microgrids(MGs).However,most existing research works on P2P energy trading among MGs ignore the influence of the dynamic network usage fees imposed by the distribution system operator(DSO).Therefore,a method of P2P energy trading among MGs based on the optimal dynamic network usage fees is proposed in this paper to balance the benefits of DSO.The interaction between DSO and MG is formulated as a Stackelberg game,in which the existence and uniqueness of optimal dynamic network usage fees are proven.Additionally,the optimal dynamic network usage fees are obtained by transforming the bi-level problem into single-level mixed-integer quadratic programming using Karush-Kuhn-Tucker conditions.Furthermore,the underlying relationship among optimal dynamic network usage fees,electrical distance,and power flow is revealed,and the mechanism of the optimal dynamic network usage fee can further enhance P2P energy trading among MGs.Finally,simulation results on an enhanced IEEE 33-bus system demonstrate that the proposed mechanism achieves a 17.08%reduction in operation costs for MG while increasing DSO revenue by 15.36%.
基金supported in part by the National Natural Science Foundation of China(No.52122706)in part by the Tsinghua University Initiative Scientific Research Program.
摘要The difficulty in capital recovery for distributed re newable energy operators(DREOs)and the high charging costs at electric vehicle charging stations(EVCSs)have long been sig nificant challenges in power systems.Collaborative operation of DREOs and EVCSs can effectively address these challenges,yet few studies have approached incentivizing collaboration from the perspective of profit allocation.Therefore,this paper pro poses a fair and efficient profit allocation method.Incorporat ing the Gauss-Legendre quadrature formula into the AumannShapley value(GL-AS)method enables efficient calculation of the profit allocation of cooperative members.However,existing literature only discusses the profit allocation method of conven tional power generation units,limiting its applicability.This pa per addresses the problem of energy storage system(ESS)switching between charging and discharging in any time inter val and the time-varying problem of renewable energy power output,thereby ensuring the efficiency of the solution process.Furthermore,a novel profit allocation adjustment model is pro vided through the adoption of triangular fuzzy comprehensive evaluation(TFCE).Finally,the effectiveness of the proposed profit allocation method is validated through numerical simula tions in various scenarios.
摘要It is to be expected that the number of electric vehicles will be growing in the near future. This trend comes together with the development of smaller decentralized generation units, like PV (photo voltaic). Together with the change on demand side that comes with the global "electrification", this can lead to serious grid congestion in low voltage grids and massive grid investments in solving this congestion. Smart charging can partly solve this issue, but with using a connected EV (electric vehicle) as a small distribution unit, combined with bi-directional charging or V2G (vehicle-to-grid) technology, these investments can be reduced to a minimum. In Lombok, Utrecht, the Netherlands, an innovative pilot was initiated with smart solar charging stations, shared electric vehicles and AC (alternating current) V2G technology. This unique combination proves that EVs are an opportunity for the grid rather than a threat. A unique partnership with OEM Renault was established to develop an AC V2G vehicle product line and work on open standardized communication between the EV, the charging station and the grid.
摘要The main faults of distribution lines are divided into two types: faults caused by natural factors and faults caused by human factors. Natural factors are inevitable and unpredictable. When the weather forecast center issues a special disaster warning, the power company needs to make preparations in advance, equip maintenance personnel for areas that may suffer from power failure caused by lightning and storm, and take timely countermeasures in case of problems, so as to restore power supply as soon as possible and maintain the stability of social order. Faults caused by human factors can be avoided as far as possible, such as setting wires in places that people can't touch easily or providing police equipment slogans. Although man-made damage may still be caused in some cases, man-made factors are more avoidable than natural factors. Attention should also be paid to the situation that the staff of the power department do not consider carefully when erecting wires, which will directly lead to the damage of human factors. At the same time, it is also the basis for the existence of human induced fault factors.
摘要At present, most of the problems existing in the operation and maintenance of power grid are related to power grid automation technology. If there are problems in the application of distribution automation technology, on the one hand, it will reduce the reliability of power grid, on the other hand, it will reduce the rapidity of power distribution. It can be seen that the distribution automation technology is very important for the normal operation and maintenance of power grid, and the relevant key in the application of distribution automation technology needs in-depth analysis and research.
摘要With the rapid development of social economy, people's living standard is becoming higher and higher. As a national basic industry, power industry is of great significance to social development. China's power enterprises mainly serve customers through distribution network, and the degree of automation of distribution network directly determines the reliability of power supply. At present, all kinds of science and technology are developing rapidly. Electric power enterprises should continuously improve the automation level of distribution network, effectively improve the reliability of power supply, maximize the efficiency of enterprise power distribution, meet the normal electricity demand of social residents, and promote the rapid development of social economy. Next, the article focuses on the application of distribution automation technology in distribution network operation and maintenance.
基金National Basic Research Program of China(2013CB632800)National Key Research and Development Program(2016YFB0402303)+2 种基金National Natural Science Foundation of China(NSFC)(61404131,61435014,61674144,61574136,61627822)Chinese Academy of Sciences Key Project(CAS Key Project)(QYZDJ-SSWJSC027,ZDRW-XH-2016-4)Natural Science Foundation of Beijing Municipality(4162060,4172060)
摘要We report an index-coupled distributed feedback quantum cascade laser by employing an equivalent phase shift(EPS) of quarter-wave integrated with a distributed Bragg reflector(DBR) at λ~5.03 μm. The EPS is fabricated through extending one sampling period by 50% in the center of a sampled Bragg grating. The key EPS and DBR pattern are fabricated by conventional holographic exposure combined with the optical photolithography technology, which leads to improved flexibility, repeatability, and cost-effectiveness. Stable single-mode emission can be obtained by changing the injection current or heat sink temperature even under the condition of large driving pulse width.
基金supported by the National Basic Research 973 Program of China under Grant No.2011CB302304the NationalHigh Technology Research and Development 863 Program of China under Grant Nos.2011AA01A102 and 2013AA013205+1 种基金the StrategicPriority Research Program of the Chinese Academy of Sciences under Grant No.XDA06010401the Chinese Academy of SciencesKey Deployment Project under Grant No.KGZD-EW-103-5(7)
摘要Distributed metadata consistency is one of the critical issues of metadata clusters in distributed file systems. Existing methods to maintain metadata consistency generally need several log forced write operations. Since synchronous disk IO is very inefficient, the average response time of metadata operations is greatly increased. In this paper, an asynchronous atomic commit protocol (ACP) named Dual-Log (DL) is presented. It does not need any log forced write operations. Optimizing for distributed metadata operations involving only two metadata servers, DL mutually records the redo log in counterpart metadata servers by transferring through the low latency network. A crashed metadata server can redo the metadata operation with the redundant redo log. Since the latency of the network is much lower than the latency of disk IO, DL can improve the performance of distributed metadata service significantly. The prototype of DL is implemented based on local journal. The performance is tested by comparing with two widely used protocols, EP and S2PC-MP, and the results show that the average response time of distributed metadata operations is reduced by about 40%-60%, and the recovery time is only I second under 10 thousands uncompleted distributed metadata operations.
摘要Fault restoration techniques have always been crucial for distribution system operators(DSOs).In the last decade,it started to gain more and more importance due to the introduction of output-based regulations where DSO performances are evaluated according to frequency and duration of energy supply interruptions.The paper presents a tabu-searchbased algorithm able to assist distribution network operational engineers in identifying solutions to restore the energy supply after permanent faults.According to the network property,two objective functions are considered to optimize either reliability or resiliency.The mathematical formulation includes the traditional feeders,number of switching operation limit,and radiality constraints.Thanks to the DSO of Milan,Unareti,the proposed algorithm has been tested on a real distribution network to investigate its effectiveness.