When deploying workflows in cloud environments,the use of Spot Instances(SIs)is intriguing as they are much cheaper than on-demand ones.However,Sls are volatile and may be revoked at any time,which results in a more c...When deploying workflows in cloud environments,the use of Spot Instances(SIs)is intriguing as they are much cheaper than on-demand ones.However,Sls are volatile and may be revoked at any time,which results in a more challenging scheduling problem involving execution interruption and hence hinders the successful handling of conventional cloud workflow scheduling techniques.Although some scheduling methods for Sls have been proposed,most of them are no more applicable to the latest Sls,as they have evolved by eliminating bidding and simplifying the pricing model.This study focuses on how to minimize the execution cost with a deadline constraint when deploying a workflow on volatile Sls in cloud environments.Based on Monte Carlo simulation and list scheduling,a stochastic scheduling method called MCLS is devised to optimize a utility function introduced for this problem.With the Monte Carlo simulation framework,MCLS employs sampled task execution time to build solutions via deadline distribution and list scheduling,and then returns the most robust solution from all the candidates with a specific evaluation mechanism and selection criteria.Experimental results show that the performance of MCLS is more competitive comparedwithtraditionalalgorithms.展开更多
This paper proposes a day-ahead dispatch framework of thermostatically controlled loads(TCLs) for system peak load reduction. The proposed day-ahead scheduling framework estimates the user’s indoor thermal comfort de...This paper proposes a day-ahead dispatch framework of thermostatically controlled loads(TCLs) for system peak load reduction. The proposed day-ahead scheduling framework estimates the user’s indoor thermal comfort degree through the building thermal inertia modelling. Based on the thermal comfort estimation, a dayahead TCL scheduling model is formulated, which consists of 3 stages: TCL aggregator estimates maximal controllable TCL capacities at each scheduling time interval by solving a optimization model;[ the system operator performs the day-ahead system dispatch to determine the load shedding instruction for each aggregator;and ′the TCL aggregator schedules the ON/OFFcontrol actions of the TCL groups based on the instruction from the system operator. A heuristic based optimization method, history driven differential evolution(HDDE)algorithm, is employed to solve the day-ahead dispatch model of the TCL aggregator side. Simulations are conducted to validate the proposed model.展开更多
Modern power systems are rapidly evolving into complex cyber-physical systems. The increasingly complex interaction among different energy entities calls for a secure, efficient, and robust cyber infrastructure. As an...Modern power systems are rapidly evolving into complex cyber-physical systems. The increasingly complex interaction among different energy entities calls for a secure, efficient, and robust cyber infrastructure. As an emerging distributed computing technology, Blockchain provides a secure environment to support such interactions.This paper gives a prospective on using Blockchain as a secure, distributed cyber infrastructure for the future grid.Firstly, the basic principles of Blockchain and its state-ofthe-art are introduced. Then, a Blockchain based smart grid cyber-physical infrastructure model is proposed. Afterwards, some promising application domains of Blockchain in future grids are presented. Following this, some potential challenges are discussed.展开更多
An optimal sizing method is proposed in this paper for mobile battery energy storage system(MBESS)in the distribution system with renewables.The optimization is formulated as a bi-objective problem,considering the rel...An optimal sizing method is proposed in this paper for mobile battery energy storage system(MBESS)in the distribution system with renewables.The optimization is formulated as a bi-objective problem,considering the reliability improvement and energy transaction saving,simultaneously.To evaluate the reliability of distribution system with MBESS and intermittent generation sources,a new framework is proposed,which is based on zone partition and identification of circuit minimal tie sets.Both analytic and simulation methods for reliability assessment are presented and compared in the framework.Case studies on a modified IEEE benchmark system have verified the performance of the proposed approach.展开更多
The design of electrical layout is a key element in the offshore wind farm planning.We present a novel electrical layout design optimization method for offshore wind farms in this paper.The proposed method can be used...The design of electrical layout is a key element in the offshore wind farm planning.We present a novel electrical layout design optimization method for offshore wind farms in this paper.The proposed method can be used to generate the network model based on fuzzy c-means(FCM)and binary integer programming(BIP)methods.It can automatically allocate wind turbines to the nearest substations and obtain the topology structure of cables utilized to connect wind turbines or turbine and substation.The objective of this optimization is to minimize the investment costs of cable connection and the transmission power losses.The results of case study clearly demonstrated the feasibility of the proposed method and showed that it can be used as a reliable tool for electrical layout design of offshore wind farms.展开更多
Following the deregulation of the power industry,transmission expansion planning(TEP)has become more complicated due to the presence of uncertainties and conflicting objectives in a market environment.Also,the growing...Following the deregulation of the power industry,transmission expansion planning(TEP)has become more complicated due to the presence of uncertainties and conflicting objectives in a market environment.Also,the growing concern on global warming highlights the importance of considering carbon pricing policies during TEP.In this paper,a probabilistic TEP approach is proposed with the integration of a chance constrained load curtailment index.The formulated dynamic programming problem is solved by a hybrid solution algorithm in an iterative process.The performance of our approach is demonstrated by case studies on a modified IEEE 14-bus system.Simulation results prove that our approach can provide network planners with comprehensive information regarding effects of uncertainties on TEP schemes,allowing them to adjust planning strategies based on their risk aversion levels or financial constraints.展开更多
Static security assessment(SSA) is an important procedure to ensure the static security of the power system.Researches recently show that cyber-attacks might be a critical hazard to the secure and economic operations ...Static security assessment(SSA) is an important procedure to ensure the static security of the power system.Researches recently show that cyber-attacks might be a critical hazard to the secure and economic operations of the power system. In this paper, the influences of false data injection attack(FDIA) on the power system SSA are studied. FDIA is a major kind of cyber-attacks that can inject malicious data into meters, cause false state estimation results, and evade being detected by bad data detection. It is firstly shown that the SSA results could be manipulated by launching a successful FDIA, which can lead to incorrect or unnecessary corrective actions. Then,two kinds of targeted scenarios are proposed, i.e., fake secure signal attack and fake insecure signal attack. The former attack will deceive the system operator to believe that the system operates in a secure condition when it is actually not. The latter attack will deceive the system operator to make corrective actions, such as generator rescheduling, load shedding, etc. when it is unnecessary and costly. The implementation of the proposed analysis is validated with the IEEE-39 benchmark system.展开更多
Thermostatically controlled loads(TCLs)have great potentials to participate in the demand response programs due to their flexibility in storing thermal energy.The two-way communication infrastructure of smart grids pr...Thermostatically controlled loads(TCLs)have great potentials to participate in the demand response programs due to their flexibility in storing thermal energy.The two-way communication infrastructure of smart grids provides opportunities for the smart buildings/houses equipped with TCLs to be aggregated in their participation in the electricity markets.This paper focuses on the realtime scheduling of TCL aggregators in the power market using the structure of the Nordic electricity markets a case study.An International Organization of Standardization(ISO)thermal comfort model is employed to well control the occupants’thermal comfort,while a rolling horizon optimization(RHO)strategy is proposed for the TCL aggregator to maximize its profit in the regulation market and to mitigate the impacts of system uncertainties.The simulations are performed by means of a metaheuristic optimization algorithm,i.e.,natural aggregation algorithm(NAA).A series of simulations are conducted to validate the effectiveness of proposed method.展开更多
Shale gas resources have the potential to sig-nificantly contribute to worldwide energy portfolio.A great number shale gas reserves have been identified in many countries.Connections of newly found gas reserves to the...Shale gas resources have the potential to sig-nificantly contribute to worldwide energy portfolio.A great number shale gas reserves have been identified in many countries.Connections of newly found gas reserves to the existing energy infrastructures are challenging,as many stakeholders and market uncertainties are involved.The proposed co-planning approach is formulated as a mixed integer nonlinear programming problem so as to minimize investments and enhance the reliability of the overall sys-tem.We propose a reliability assessment approach that is applicable for the coupled gas and electricity networks.In addition,the IEEE 24-bus RTS and a test gas system are applied to validate the performance of our approach.Based on the simulation results,the novel expansion co-planning approach is a robust and flexible decision tool,which provides network planners with comprehensive informa-tion regarding trade-offs between cost and system reliability.展开更多
Demand side management techniques have drawn significant attentions along with the development of smart grid.This paper proposes a new direct load control(DLC)model for scheduling interruptible air conditioner loads.T...Demand side management techniques have drawn significant attentions along with the development of smart grid.This paper proposes a new direct load control(DLC)model for scheduling interruptible air conditioner loads.The model is coordinated with the unit commitment and economic dispatch to minimize the total operation cost over the whole dispatch horizon.The network constraints are also considered in the model.To ensure the thermal comfort of the occupants,we are among the first to incorporate the advanced two-parameter thermal inertia dynamical model of customer houses into the DLC model to calculate the indoor temperature variation.This paper also proposes a distributed imperialist competitive algorithm to effectively solve the model.The simulation studies prove the efficiency of the proposed methodology.展开更多
Mobility as a service(MaaS)is an innovative and value-laden method to operate ondemand mobility services within the existing transport infrastructures.A big challenge for the transport system is that the transport inf...Mobility as a service(MaaS)is an innovative and value-laden method to operate ondemand mobility services within the existing transport infrastructures.A big challenge for the transport system is that the transport infrastructure cannot be restructured as quickly as a digital platform like cloud computing infrastructure services,which is a constraint that limits the balance between mobility demand and supply in real-time.The ownership of mobility services needs to be redefined to establish legal binds between service vendors and commuters,further demonstrating the capacity to balance the demand and supply of mobility services in real-time.The ownership of a mobility service is defined as the commuter’s right to use the mobility service provided by the service vendor under agreed terms and conditions.This is facilitated by MobiToken in this study.An eMarketplace is proposed for commuters,mobility service vendors and other stakeholders to exchange MobiToken,where the marketplace demonstrates the potential use of blockchain tools,methods and algorithms,where a specialised capability for reliably link stakeholders is proposed through a nonrevertible blockchain dataset.The bidden price of MobiToken reflects the demand for mobility services in the real world,where congestion charges are incorporated within the bidden price.The performance of the preliminary platform is evaluated with three testing scenarios,and the results of performance testing indicate the stability and reliability of the Raft consensus algorithm for the blockchain database.展开更多
基金This work was supported by the National Natural Science Foundation of China(Nos.62172065 and 62072060)the Natural Science Foundation of Chongqing(No.cstc2020jcyj-msxmX0137).
文摘When deploying workflows in cloud environments,the use of Spot Instances(SIs)is intriguing as they are much cheaper than on-demand ones.However,Sls are volatile and may be revoked at any time,which results in a more challenging scheduling problem involving execution interruption and hence hinders the successful handling of conventional cloud workflow scheduling techniques.Although some scheduling methods for Sls have been proposed,most of them are no more applicable to the latest Sls,as they have evolved by eliminating bidding and simplifying the pricing model.This study focuses on how to minimize the execution cost with a deadline constraint when deploying a workflow on volatile Sls in cloud environments.Based on Monte Carlo simulation and list scheduling,a stochastic scheduling method called MCLS is devised to optimize a utility function introduced for this problem.With the Monte Carlo simulation framework,MCLS employs sampled task execution time to build solutions via deadline distribution and list scheduling,and then returns the most robust solution from all the candidates with a specific evaluation mechanism and selection criteria.Experimental results show that the performance of MCLS is more competitive comparedwithtraditionalalgorithms.
基金supported in part by an AustralianResearch Council Future Fellowship scheme (No. FT140100130)in part by an Australian Research Discovery Project (No. DP170103427)
文摘This paper proposes a day-ahead dispatch framework of thermostatically controlled loads(TCLs) for system peak load reduction. The proposed day-ahead scheduling framework estimates the user’s indoor thermal comfort degree through the building thermal inertia modelling. Based on the thermal comfort estimation, a dayahead TCL scheduling model is formulated, which consists of 3 stages: TCL aggregator estimates maximal controllable TCL capacities at each scheduling time interval by solving a optimization model;[ the system operator performs the day-ahead system dispatch to determine the load shedding instruction for each aggregator;and ′the TCL aggregator schedules the ON/OFFcontrol actions of the TCL groups based on the instruction from the system operator. A heuristic based optimization method, history driven differential evolution(HDDE)algorithm, is employed to solve the day-ahead dispatch model of the TCL aggregator side. Simulations are conducted to validate the proposed model.
基金supported by the Australian Research Council Discovery Projects(Nos.DP170103427,DP180103217)
文摘Modern power systems are rapidly evolving into complex cyber-physical systems. The increasingly complex interaction among different energy entities calls for a secure, efficient, and robust cyber infrastructure. As an emerging distributed computing technology, Blockchain provides a secure environment to support such interactions.This paper gives a prospective on using Blockchain as a secure, distributed cyber infrastructure for the future grid.Firstly, the basic principles of Blockchain and its state-ofthe-art are introduced. Then, a Blockchain based smart grid cyber-physical infrastructure model is proposed. Afterwards, some promising application domains of Blockchain in future grids are presented. Following this, some potential challenges are discussed.
基金This work was supported by the National Natural Science Foundation of China(Young Scholar Program 71401017,General Program 51277016)State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources(Grant No.LAPS14002)+1 种基金Fujian regional science and technology major projects,China(2013H41010151)Hong Kong RGC Theme Based Research Scheme Grant No.T23-407/13-N.
文摘An optimal sizing method is proposed in this paper for mobile battery energy storage system(MBESS)in the distribution system with renewables.The optimization is formulated as a bi-objective problem,considering the reliability improvement and energy transaction saving,simultaneously.To evaluate the reliability of distribution system with MBESS and intermittent generation sources,a new framework is proposed,which is based on zone partition and identification of circuit minimal tie sets.Both analytic and simulation methods for reliability assessment are presented and compared in the framework.Case studies on a modified IEEE benchmark system have verified the performance of the proposed approach.
文摘The design of electrical layout is a key element in the offshore wind farm planning.We present a novel electrical layout design optimization method for offshore wind farms in this paper.The proposed method can be used to generate the network model based on fuzzy c-means(FCM)and binary integer programming(BIP)methods.It can automatically allocate wind turbines to the nearest substations and obtain the topology structure of cables utilized to connect wind turbines or turbine and substation.The objective of this optimization is to minimize the investment costs of cable connection and the transmission power losses.The results of case study clearly demonstrated the feasibility of the proposed method and showed that it can be used as a reliable tool for electrical layout design of offshore wind farms.
文摘Following the deregulation of the power industry,transmission expansion planning(TEP)has become more complicated due to the presence of uncertainties and conflicting objectives in a market environment.Also,the growing concern on global warming highlights the importance of considering carbon pricing policies during TEP.In this paper,a probabilistic TEP approach is proposed with the integration of a chance constrained load curtailment index.The formulated dynamic programming problem is solved by a hybrid solution algorithm in an iterative process.The performance of our approach is demonstrated by case studies on a modified IEEE 14-bus system.Simulation results prove that our approach can provide network planners with comprehensive information regarding effects of uncertainties on TEP schemes,allowing them to adjust planning strategies based on their risk aversion levels or financial constraints.
基金supported by the Hong Kong Polytechnic University(1-YW1Q)
文摘Static security assessment(SSA) is an important procedure to ensure the static security of the power system.Researches recently show that cyber-attacks might be a critical hazard to the secure and economic operations of the power system. In this paper, the influences of false data injection attack(FDIA) on the power system SSA are studied. FDIA is a major kind of cyber-attacks that can inject malicious data into meters, cause false state estimation results, and evade being detected by bad data detection. It is firstly shown that the SSA results could be manipulated by launching a successful FDIA, which can lead to incorrect or unnecessary corrective actions. Then,two kinds of targeted scenarios are proposed, i.e., fake secure signal attack and fake insecure signal attack. The former attack will deceive the system operator to believe that the system operates in a secure condition when it is actually not. The latter attack will deceive the system operator to make corrective actions, such as generator rescheduling, load shedding, etc. when it is unnecessary and costly. The implementation of the proposed analysis is validated with the IEEE-39 benchmark system.
基金supported in part by the Australian Research Council through its Future Fellowship scheme(No.FT140100130)in part by the Visiting Scholarship of State Key Laboratory of Power Transmission Equipment&System Security and New Technology(Chongqing University,China)(No.2007DA10512716401)in part by the Early Career Research Development Scheme of Faculty of Engineering and Information Technology,University of Sydney,Australia
文摘Thermostatically controlled loads(TCLs)have great potentials to participate in the demand response programs due to their flexibility in storing thermal energy.The two-way communication infrastructure of smart grids provides opportunities for the smart buildings/houses equipped with TCLs to be aggregated in their participation in the electricity markets.This paper focuses on the realtime scheduling of TCL aggregators in the power market using the structure of the Nordic electricity markets a case study.An International Organization of Standardization(ISO)thermal comfort model is employed to well control the occupants’thermal comfort,while a rolling horizon optimization(RHO)strategy is proposed for the TCL aggregator to maximize its profit in the regulation market and to mitigate the impacts of system uncertainties.The simulations are performed by means of a metaheuristic optimization algorithm,i.e.,natural aggregation algorithm(NAA).A series of simulations are conducted to validate the effectiveness of proposed method.
基金This work is partly supported by CSIRO Future Grid Flagship Grant Project 2 co-planning and optimization of gas and electricity networks.
文摘Shale gas resources have the potential to sig-nificantly contribute to worldwide energy portfolio.A great number shale gas reserves have been identified in many countries.Connections of newly found gas reserves to the existing energy infrastructures are challenging,as many stakeholders and market uncertainties are involved.The proposed co-planning approach is formulated as a mixed integer nonlinear programming problem so as to minimize investments and enhance the reliability of the overall sys-tem.We propose a reliability assessment approach that is applicable for the coupled gas and electricity networks.In addition,the IEEE 24-bus RTS and a test gas system are applied to validate the performance of our approach.Based on the simulation results,the novel expansion co-planning approach is a robust and flexible decision tool,which provides network planners with comprehensive informa-tion regarding trade-offs between cost and system reliability.
基金This work was supported in part by National Natural Science Foundation of China(Key Project 71331001,General Project 71371065,11171095,71071025).
文摘Demand side management techniques have drawn significant attentions along with the development of smart grid.This paper proposes a new direct load control(DLC)model for scheduling interruptible air conditioner loads.The model is coordinated with the unit commitment and economic dispatch to minimize the total operation cost over the whole dispatch horizon.The network constraints are also considered in the model.To ensure the thermal comfort of the occupants,we are among the first to incorporate the advanced two-parameter thermal inertia dynamical model of customer houses into the DLC model to calculate the indoor temperature variation.This paper also proposes a distributed imperialist competitive algorithm to effectively solve the model.The simulation studies prove the efficiency of the proposed methodology.
文摘Mobility as a service(MaaS)is an innovative and value-laden method to operate ondemand mobility services within the existing transport infrastructures.A big challenge for the transport system is that the transport infrastructure cannot be restructured as quickly as a digital platform like cloud computing infrastructure services,which is a constraint that limits the balance between mobility demand and supply in real-time.The ownership of mobility services needs to be redefined to establish legal binds between service vendors and commuters,further demonstrating the capacity to balance the demand and supply of mobility services in real-time.The ownership of a mobility service is defined as the commuter’s right to use the mobility service provided by the service vendor under agreed terms and conditions.This is facilitated by MobiToken in this study.An eMarketplace is proposed for commuters,mobility service vendors and other stakeholders to exchange MobiToken,where the marketplace demonstrates the potential use of blockchain tools,methods and algorithms,where a specialised capability for reliably link stakeholders is proposed through a nonrevertible blockchain dataset.The bidden price of MobiToken reflects the demand for mobility services in the real world,where congestion charges are incorporated within the bidden price.The performance of the preliminary platform is evaluated with three testing scenarios,and the results of performance testing indicate the stability and reliability of the Raft consensus algorithm for the blockchain database.
