As the power system transitions to a new green and low-carbon paradigm,the penetration of renewable energy in China’s power system is gradually increasing.However,the variability and uncertainty of renewable energy o...As the power system transitions to a new green and low-carbon paradigm,the penetration of renewable energy in China’s power system is gradually increasing.However,the variability and uncertainty of renewable energy output limit its profitability in the electricity market and hinder its market-based integration.This paper first constructs a wind-solar-thermalmulti-energy complementary system,analyzes its external game relationships,and develops a bi-level market optimization model.Then,it considers the contribution levels of internal participants to establish a comprehensive internal distribution evaluation index system.Finally,simulation studies using the IEEE 30-bus system demonstrate that the multi-energy complementary system stabilizes nodal outputs,enhances the profitability of market participants,and promotes the market-based integration of renewable energy.展开更多
Technological parameters of asymmetric cast-rolling under multi-energy field were investigated on horizontal twin roll caster（d400 mm×500 mm）, and their effects on structures and properties of 1050 strips were ...Technological parameters of asymmetric cast-rolling under multi-energy field were investigated on horizontal twin roll caster（d400 mm×500 mm）, and their effects on structures and properties of 1050 strips were analyzed by comparing with traditional cast-rolling. Results show that when length of cast-rolling area is 70 mm, melt temperature of head box is 670 °C, cast rolling speed is 1.3 m/min, exciting current is 10 A, center frequency is（13±1） Hz, ultrasonic power is 200 W and ultrasonic frequency is（20±0.2） kHz, the 1050 strip with the best microstructure can be prepared successfully; its center segregated layer disappears; the average grain size is reduced by about 40%; the crystal grains are distributed evenly; micro segregation decreases obviously; the precipitated phases are distributed along the grain boundaries evenly; and the tensile strength, yield strength, elongation and micro-hardness of cast-rolled strip are improved by 22.6%, 23.66%, 38.75% and 9.90%, respectively.展开更多
To integrate different renewable energy resources effectively in a microgrid, a configuration optimization model of a multi-energy distributed generation（DG） system and its auxiliary equipment is proposed. The model...To integrate different renewable energy resources effectively in a microgrid, a configuration optimization model of a multi-energy distributed generation（DG） system and its auxiliary equipment is proposed. The model mainly consists of two parts, the determination of initial configuration schemes according to user preference and the selection of the optimal scheme. The comprehensive evaluation index（CEI）, which is acquired through the analytic hierarchy process（AHP） weight calculation method, is adopted as the evaluation criterion to rank the initial schemes. The optimal scheme is obtained according to the ranking results. The proposed model takes the diversity of different equipment parameters and investment cost into consideration and can give relatively suitable and economical suggestions for system configuration.Additionally, unlike Homer Pro, the proposed model considers the complementation of different renewable energy resources, and thus the rationality of the multi-energy DG system is improved compared with the single evaluation criterion method which only considers the total cost.展开更多
In response to the underutilization of energy and insufficient flexible operation capability of rural energy supply systems in China,this study proposes an optimal dispatch approach for a rural multi-energy supply sys...In response to the underutilization of energy and insufficient flexible operation capability of rural energy supply systems in China,this study proposes an optimal dispatch approach for a rural multi-energy supply system(RMESS)considering virtual energy storage(VES).First,to enable the flexible utilization of rural biomass resources and the thermal inertia of residential building envelopes,this study constructed VES-I and VES-II models that describe electrical-thermal and electrical-gas coupling from an electrical viewpoint.Subsequently,an RMESS model encompassing these two types of VES was formulated.This model delineates the intricate interplay of multi-energy components within the RMESS framework and facilitates the precise assessment of the adjustable potential for optimizing RMESS operations.Based on the above models,a day-ahead optimal dispatch model for an RMESS considering a VES is proposed to achieve optimal economic performance while ensuring efficient energy allocation.Comparative simulations validated the effectiveness of the VES modeling and the day-ahead optimal dispatch approach for the RMESS.展开更多
The production process of iron and steel is accompanied by a large amount of energy production and consumption. Optimal scheduling and utilization of these energies within energy systems are crucial to realize a reduc...The production process of iron and steel is accompanied by a large amount of energy production and consumption. Optimal scheduling and utilization of these energies within energy systems are crucial to realize a reduction in the cost, energy use, and CO_2 emissions.However, it is difficult to model and schedule energy usage within steel works because different types of energy and devices are involved. The energy hub(EH), as a universal modeling frame, is widely used in multi-energy systems to improve its efficiency, flexibility, and reliability.This paper proposed an efficient multi-layer model based on the EH concept, which is designed to systematically model the energy system and schedule energy within steelworks to meet the energy demand. Besides, to simulate the actual working conditions of the energy devices, the method of fitting the curve is used to describe the efficiency of the energy devices. Moreover, to evaluate the applicability of the proposed model, a case study is conducted to minimize both the economic operation cost and CO_2 emissions. The optimal results demonstrated that the model is suitable for energy systems within steel works. Further, the economic operation cost decreased by 3.41%, and CO_2 emissions decreased by approximately 3.67%.展开更多
Multi-energy microgrids(MEMG)play an important role in promoting carbon neutrality and achieving sustainable development.This study investigates an effective energy management strategy(EMS)for MEMG.First,an energy man...Multi-energy microgrids(MEMG)play an important role in promoting carbon neutrality and achieving sustainable development.This study investigates an effective energy management strategy(EMS)for MEMG.First,an energy management system model that allows for intra-microgrid energy conversion is developed,and the corresponding Markov decision process(MDP)problem is formulated.Subsequently,an improved double deep Q network(iDDQN)algorithm is proposed to enhance the exploration ability by modifying the calculation of the Q value,and a prioritized experience replay(PER)is introduced into the iDDQN to improve the training speed and effectiveness.Finally,taking advantage of the federated learning(FL)and iDDQN algorithms,a federated iDDQN is proposed to design an MEMG energy management strategy to enable each microgrid to share its experiences in the form of local neural network(NN)parameters with the federation layer,thus ensuring the privacy and security of data.The simulation results validate the superior performance of the proposed energy management strategy in minimizing the economic costs of the MEMG while reducing CO_2 emissions and protecting data privacy.展开更多
In a multi-energy collaboration system, cooling, heating, electricity, and other energy components are coupled to complement each other. Through multi-energy coordination and cooperation, they can significantly improv...In a multi-energy collaboration system, cooling, heating, electricity, and other energy components are coupled to complement each other. Through multi-energy coordination and cooperation, they can significantly improve their individual operating efficiency and overall economic benefits. Demand response, as a multi-energy supply and demand balance method, can further improve system flexibility and economy. Therefore, a multi-energy cooperative system optimization model has been proposed, which is driven by price-based demand response to determine the impact of power-demand response on the optimal operating mode of a multi-energy cooperative system. The main components of the multi-energy collaborative system have been analyzed. The multi-energy coupling characteristics have been identified based on the energy hub model. Using market elasticity as a basis, a price-based demand response model has been built. The model has been optimized to minimize daily operating cost of the multi-energy collaborative system. Using data from an actual situation, the model has been verified, and we have shown that the adoption of price-based demand response measures can significantly improve the economy of multi-energy collaborative systems.展开更多
The temporal and spatial characteristics of seasonal hydrogen storage will play a very important role in the coupling of multi-energy systems.This essay believes that there are several key issues worth noting in the s...The temporal and spatial characteristics of seasonal hydrogen storage will play a very important role in the coupling of multi-energy systems.This essay believes that there are several key issues worth noting in the seasonal hydrogen storage coupled multi-energy system,namely,hydrogen storage methods,coupling models,and benefit evaluation.Through research,this article innovatively divides seasonal hydrogen storage into two types:space transfer hydrogen storage technology and time transfer physical property conversion hydrogen storage technology.Then sort out the two most typical seasonal hydrogen storage multi-energy system application scenarios and their hydrogen storage unit models.Finally,it is shown that hydrogen storage methods should be selected according to different periods of time and regions,and the benefits should be evaluated before they can be used in practice.This review study is applicable to the process of coupling seasonal hydrogen storage in multi-energy systems.Hydrogen energy is used as an intermediate energy link for the selection,evaluation and modeling of the optimal selection and rational utilization.展开更多
In the background of the large-scale development and utilization of renewable energy,the joint operation of a variety of heterogeneous energy sources has become an inevitable development trend.However,the physical cha...In the background of the large-scale development and utilization of renewable energy,the joint operation of a variety of heterogeneous energy sources has become an inevitable development trend.However,the physical characteristics of different power sources and the inherent uncertainties of renewable energy power generation have brought difficulties to the planning,operation and control of power systems.For now,the utilization of multi-energy complementarity to promote energy transformation and improve the consumption of renewable energy has become a common understanding among researchers and the engineering community.This paper makes a review of the research on complementarity of new energy high proportion multi-energy systems from uncertainty modeling,complementary characteristics,planning and operation.We summarize the characteristics of the existing research and provide a reference for the further work.展开更多
In order to solve the core issue of the energy regulation （ER） on multi-energy resource powertrain of fuel cell vehicle, the work functions of each component were defined; the mathematical algorithm model of energy ...In order to solve the core issue of the energy regulation （ER） on multi-energy resource powertrain of fuel cell vehicle, the work functions of each component were defined; the mathematical algorithm model of energy regulation was established and the relevant solution was found. This algorithm was evaluated successfully on the hardware in loop （FILL） platform under three typical urban running cycles. The results showed ER control target had been realized and the mathematical algorithm was effective and reasonable. Based on the HIL simulation, some conclusions and ER strategies were made. According to the different power component parameters and real time control request, this algorithm should be modified and calibrated for application in the actual control system.展开更多
Multi-energy flow (MEF) coupling is one of the key features of the energy Internet and integrated energy systems that are different from smart grids. With the increasing coupling of heterogeneous energy flow, the syst...Multi-energy flow (MEF) coupling is one of the key features of the energy Internet and integrated energy systems that are different from smart grids. With the increasing coupling of heterogeneous energy flow, the system characteristics of coupling are becoming more and more obvious and more complicated. The modeling, analysis and control methods of traditional single flow systems have not been applied directly. Therefore, it is necessary to study the modeling of multi-energy flow coupling, the power flow analysis, optimization and control method of heterogeneous energy flow, which plays the role of multi-energy flow synergy to avoid the adverse effects of coupling. This paper summarizes the current research situation of energy Internet at home and abroad from the aspects of modeling of multi-energy flow, power flow calculation and optimal dispatching, and analyzes the existing problems in the research of these aspects.展开更多
The multi-energy complementary distributed energy system (MCDES) covers a variety of energy forms, involves complex operation modes, and contains a wealth of control equipment and coupling links. It can realize the co...The multi-energy complementary distributed energy system (MCDES) covers a variety of energy forms, involves complex operation modes, and contains a wealth of control equipment and coupling links. It can realize the complementary and efficient use of different types of energy, which is the basic component of the physical layer of the Energy Internet. In this paper, aiming at the demand of the energy application for towns, a distributed energy system based on multi-energy complementary is constructed. Firstly, the supply condition of the distributed energy for the demonstration project is analyzed, and the architecture of the multi-energy complementary distributed energy system is established. Then the regulation strategy of the multi-energy complementary distributed energy system is proposed. Finally, an overall system scheme for the multi-energy complementary distributed energy system suitable for towns is developed, which provides a solid foundation for the development and promotion of the multi-energy complementary distributed energy system.展开更多
We present a non-destructive method (NDM) to identify minute quantities of high atomic number (<em>Z</em>) elements in containers such as passenger baggage, goods carrying transport trucks, and environment...We present a non-destructive method (NDM) to identify minute quantities of high atomic number (<em>Z</em>) elements in containers such as passenger baggage, goods carrying transport trucks, and environmental samples. This method relies on the fact that photon attenuation varies with its energy and properties of the absorbing medium. Low-energy gamma-ray intensity loss is sensitive to the atomic number of the absorbing medium, while that of higher-energies vary with the density of the medium. To verify the usefulness of this feature for NDM, we carried out simultaneous measurements of intensities of multiple gamma rays of energies 81 to 1408 keV emitted by sources<sup> 133</sup>Ba (half-life = 10.55 y) and <sup>152</sup>Eu (half-life = 13.52 y). By this arrangement, we could detect minute quantities of lead and copper in a bulk medium from energy dependent gamma-ray attenuations. It seems that this method will offer a reliable, low-cost, low-maintenance alternative to X-ray or accelerator-based techniques for the NDM of high-Z materials such as mercury, lead, uranium, and transuranic elements etc.展开更多
The latest generation of aero engines has set higher standards for thrust-to-weight ratio and energy conversion efficiency,making it imperative to address the challenge of efficiently and accurately machining film coo...The latest generation of aero engines has set higher standards for thrust-to-weight ratio and energy conversion efficiency,making it imperative to address the challenge of efficiently and accurately machining film cooling holes.It has been demonstrated that conventional long-pulse lasers are incapable of meeting the elevated quality surface finish requirements for these holes,a consequence of the severe thermal defects.The employment of backside water-assisted laser drilling technology confers a number of distinct advantages in terms of mitigating laser thermal damage,thus representing a highly promising solution to this challenge.However,significant accumulation of bubbles and machining products during the backside water-assisted laser drilling process has been demonstrated to have a detrimental effect on laser transmission and machining stability,thereby reducing machining quality.In order to surmount these challenges,a novel method has been proposed,namely an ultrasonic shock water flow-assisted picosecond laser drilling technique.Numerical models for ultrasonic acoustic streaming and particle tracking for machining product transport have been established to investigate the mechanism.The simulation results demonstrated that the majority of the machining products could rapidly move away from the machining area because of the action of acoustic streaming,thereby avoiding the accumulation of bubbles and products.Subsequent analysis,comparing the process performance in micro-hole machining,confirmed that the ultrasonic field could effectively eliminate bubble and chip accumulation,thus significantly improving micro-hole quality.Furthermore,the impact of ultrasonic and laser parameters on micro-hole quality under varying machining methods was thoroughly investigated.The findings demonstrated that the novel methodology outlined in this study yielded superior-quality micro-holes at elevated ultrasonic and laser power levels,in conjunction with reduced laser frequency and scanning velocity.The taper of the micro-holes produced by the new method was reduced by more than 25%compared with the other conventional methods.展开更多
Generally,energy trading in smart grid is realized by microgrids.Correspondingly,energy trading in energy internet relies on small-scale energy systems,named as Weenergies(WEs).Previous works on the distributed energy...Generally,energy trading in smart grid is realized by microgrids.Correspondingly,energy trading in energy internet relies on small-scale energy systems,named as Weenergies(WEs).Previous works on the distributed energy trading focused on the trading platform or trading mechanism based on distributed communication.However,most ignored the fact that there is no express delivery of energy trading,and the transmission of energy depends on a fixed physical topology.Energy transactions without considering the transmission distance will increase the difficulty of energy scheduling and the transmission cost of energy.Aiming at this problem,an aggregation game among WEs is proposed for two-way multi-energy trading,and a distributed algorithm is designed to solve the Nash equilibrium.Since each WE only needs to communicate with its neighbors to exchange information,this distributed process reduces communication burden and improves information security.Furthermore,a multi-energy transmission optimization model is established to determine the transmission path of the transmission energy,which can minimize the transmission cost.Subsequently,to reduce the influence of real-time fluctuations of renewable energy and load,a receding horizon control algorithm is designed to improve the reliability of the proposed game.Finally,the effectiveness in dealing with two-way multi-energy trading of the proposed strategy is verified through simulations on the five connected WEs.展开更多
Mesh-constructed and radial-operated features call for elaborate consideration of co-planning for multi-energy distribution systems(MEDS).Considering a reconfiguration channel can be constructed in advance to cope wit...Mesh-constructed and radial-operated features call for elaborate consideration of co-planning for multi-energy distribution systems(MEDS).Considering a reconfiguration channel can be constructed in advance to cope with extreme N-1 contingencies,this paper proposes a hierarchical robust expansion co-planning model for MEDS.By adopting convex hull relaxation and linearization techniques,the model is cast as a mixed-integer linear programming(MILP)problem with high accuracy.Specifically,the model is divided into four parts:master investment problem,feasible load cutting subproblem in normal scenarios or N-1 fault scenarios,and optimal operational subproblem.Based on defense-attack-correction methodology,a hierarchical solution incorporating adjustable N-1 contingency tolerance is developed to trade-off economy and reliability.Furthermore,a relaxation feedback method is applied to solve invalid feedback cuts of existing parameterization methods.Numerical test results justify the model can generate the best configuration for mesh-constructed MEDS,and the reconfiguration strategy under different adjustable N-1 contingency tolerances is also given as an output of the optimization.展开更多
As a frontier topic in the field of architecture,multi-energy building systems hold great significance in balancing the relationship among energy,environment and economy,as well as in promoting the green-and low-carbo...As a frontier topic in the field of architecture,multi-energy building systems hold great significance in balancing the relationship among energy,environment and economy,as well as in promoting the green-and low-carbon transformation of the construction industry.This study proposes a low-carbon scheduling strategy incorporating electricity-carbon incentive compensation.Firstly,a theoretical model of multi-energy buildings is established,enabling the coordinated regulation of distributed electricity-cooling-heating energy conversion devices to improve the energy utilisation efficiency and reduce both integrated operational and carbon trading expenses.Meanwhile,a price transmission model of electricity-carbon market is developed by combining a tiered carbon pricing scheme with reward-penalty attributes and the Chinese certified emissions reduction(CCER)mechanism,thereby facilitating system optimisation and effective control of carbon emissions.Furthermore,a multi-stakeholder game strategy with electricity-carbon incentive compensation is introduced to stimulate active engagement in energy conservation and carbon emissions reduction across various stakeholders within the system.The simulation results indicate that the proposed theoretical framework has significant advantages in enhancing the economic performance of multienergy building systems,curtailing operational expense and expanding carbon market profit,demonstrating the great potential and value for the low-carbon operation of the system to be applied and widely promoted.展开更多
Anomaly detection is crucial for data-driven applications in integrated energy systems.Traditional anomaly detection methods primarily focus on one single energy load,often neglecting potential spatial correlations be...Anomaly detection is crucial for data-driven applications in integrated energy systems.Traditional anomaly detection methods primarily focus on one single energy load,often neglecting potential spatial correlations between multivariate energy time series.Meanwhile,addressing the imbalanced nature of user-level multi-en-ergy load data remains a significant challenge.In this paper,we propose EGBAD,an Ensemble Graph-Boosted Anomaly Detection framework for user-level multi-energy load that leverages the advantages of graph relational analysis and ensemble learning.First,a dynamic graph construction method based on multidimensional scaling(MDS)is proposed to transform multi-energy load data into graph representations.These graphs are subse-quently processed using graph convolutional network(GCN)to capture the spatiotemporal correlations between multi-energy load time series.In addition,to improve detection robustness under class imbalance,the entire training process is embedded within a Boosting ensemble learning framework,where the weight assigned to the minority class is progressively increased at each boosting stage.Experimental results on publicly real-world datasets demonstrate that the proposed model achieves superior anomaly detection accuracy compared to most baseline methods.Notably,it performs especially well in scenarios characterized by extreme data imbal-ance,achieving the highest recall and F1-score for anomaly detection.展开更多
The application of multi-energy hybrid power systems is conducive to tackling global warming and the low-carbon transition of the power system.A capacity allocation model of a multi-energy hybrid power system includin...The application of multi-energy hybrid power systems is conducive to tackling global warming and the low-carbon transition of the power system.A capacity allocation model of a multi-energy hybrid power system including wind power,solar power,energy storage,and thermal power was developed in this study.The evaluation index was defined as the objective function,formulated by normalizing the output fluctuation,economic cost,and carbon dioxide emissions.Calculations under different initial conditions and output electric power scenarios were carried out with genetic algorithm.The capacity allocation model was validated with the literature results,with errors of less than 5%.Results indicate that the capacity allocation modes of the multi-energy hybrid power system can be divided into thermal power dominated mode,multi-energy complementary mode,and renewable power dominated mode.In addition,the division of capacity allocation modes is not affected by the weather conditions and energy storage ratio.The capacity factor decreases from 0.4 to 0.24 as the power system changes from the thermal power dominated mode to the renewable power dominated mode.When the output electric power is 240 MW,300 MW,and 340 MW,the optimal energy storage ratio is 10%,18%,and 16%,respectively.The model developed in this study not only enriches the theory of multi-energy complementary power generation but also guides the engineering design of the wind-photovoltaics-thermal-storage system targeting smart grid and be beneficial for the middle-long-term planning of the green and low-carbon transition of the power system.展开更多
Multi-energy complementary distributed energy system(MECDES)is an important development direction for the energy system.It has the advantages of energy conservation and environmental protection and has great potential...Multi-energy complementary distributed energy system(MECDES)is an important development direction for the energy system.It has the advantages of energy conservation and environmental protection and has great potential to realize efficient energy cascade utilization through the energy conversion and utilization of cooling,heating,and power in place,achieving a user-oriented energy supply.The present study thoroughly reviews the current research status and puts forward the key scientific issues that urgently need to be resolved by investigating the problems and challenges of the MECDES from the perspectives of the characterization of the energetic mass-energy potential,the synergistic transformation and energy-potential coupling mechanism of multi-energy complementation,energy quality improvement and storage,and proactive regulation of the MECDES.Furthermore,the latest research progress of the MECDES for trickling the key scientific issues is comprehensively presented by proposing the distributed energy system with the complementation of multi-energy sources,developing novel ways of the energy potential coupling and energy cascaded comprehensive utilization of multi-energy complementation,proposing a new theory of multi-energy complementation and energy potential coupling and a new mechanism of source complementation,processing matching and thermodynamic cycle system collaborative conversion of both the fossil energy and renewable energy,and developing a new method of proactive adjust and control for adapting to fluctuating energy input and various energy load demands.Finally,the prospects and recommendations for the future research and development direction of MECDES are provided.展开更多
基金funded by the National Key R&D Program of China,grant number 2019YFB1505400.
文摘As the power system transitions to a new green and low-carbon paradigm,the penetration of renewable energy in China’s power system is gradually increasing.However,the variability and uncertainty of renewable energy output limit its profitability in the electricity market and hinder its market-based integration.This paper first constructs a wind-solar-thermalmulti-energy complementary system,analyzes its external game relationships,and develops a bi-level market optimization model.Then,it considers the contribution levels of internal participants to establish a comprehensive internal distribution evaluation index system.Finally,simulation studies using the IEEE 30-bus system demonstrate that the multi-energy complementary system stabilizes nodal outputs,enhances the profitability of market participants,and promotes the market-based integration of renewable energy.
基金Project(2014CB046702)supported by National Basic Research Program of China
文摘Technological parameters of asymmetric cast-rolling under multi-energy field were investigated on horizontal twin roll caster（d400 mm×500 mm）, and their effects on structures and properties of 1050 strips were analyzed by comparing with traditional cast-rolling. Results show that when length of cast-rolling area is 70 mm, melt temperature of head box is 670 °C, cast rolling speed is 1.3 m/min, exciting current is 10 A, center frequency is（13±1） Hz, ultrasonic power is 200 W and ultrasonic frequency is（20±0.2） kHz, the 1050 strip with the best microstructure can be prepared successfully; its center segregated layer disappears; the average grain size is reduced by about 40%; the crystal grains are distributed evenly; micro segregation decreases obviously; the precipitated phases are distributed along the grain boundaries evenly; and the tensile strength, yield strength, elongation and micro-hardness of cast-rolled strip are improved by 22.6%, 23.66%, 38.75% and 9.90%, respectively.
基金The National Natural Science Foundation of China(No.51377021)the Science and Technology Project of State Grid Corporation of China(No.SGTJDK00DWJS1600014)
文摘To integrate different renewable energy resources effectively in a microgrid, a configuration optimization model of a multi-energy distributed generation（DG） system and its auxiliary equipment is proposed. The model mainly consists of two parts, the determination of initial configuration schemes according to user preference and the selection of the optimal scheme. The comprehensive evaluation index（CEI）, which is acquired through the analytic hierarchy process（AHP） weight calculation method, is adopted as the evaluation criterion to rank the initial schemes. The optimal scheme is obtained according to the ranking results. The proposed model takes the diversity of different equipment parameters and investment cost into consideration and can give relatively suitable and economical suggestions for system configuration.Additionally, unlike Homer Pro, the proposed model considers the complementation of different renewable energy resources, and thus the rationality of the multi-energy DG system is improved compared with the single evaluation criterion method which only considers the total cost.
基金supported by Science and Technology Project of SGCC(5108-202218280A-2-375-XG)。
文摘In response to the underutilization of energy and insufficient flexible operation capability of rural energy supply systems in China,this study proposes an optimal dispatch approach for a rural multi-energy supply system(RMESS)considering virtual energy storage(VES).First,to enable the flexible utilization of rural biomass resources and the thermal inertia of residential building envelopes,this study constructed VES-I and VES-II models that describe electrical-thermal and electrical-gas coupling from an electrical viewpoint.Subsequently,an RMESS model encompassing these two types of VES was formulated.This model delineates the intricate interplay of multi-energy components within the RMESS framework and facilitates the precise assessment of the adjustable potential for optimizing RMESS operations.Based on the above models,a day-ahead optimal dispatch model for an RMESS considering a VES is proposed to achieve optimal economic performance while ensuring efficient energy allocation.Comparative simulations validated the effectiveness of the VES modeling and the day-ahead optimal dispatch approach for the RMESS.
基金financially supported by the National Key Research and Development Program of China (No.2020YFB1711102)the National Natural Science Foundation of China (No.51874095)。
文摘The production process of iron and steel is accompanied by a large amount of energy production and consumption. Optimal scheduling and utilization of these energies within energy systems are crucial to realize a reduction in the cost, energy use, and CO_2 emissions.However, it is difficult to model and schedule energy usage within steel works because different types of energy and devices are involved. The energy hub(EH), as a universal modeling frame, is widely used in multi-energy systems to improve its efficiency, flexibility, and reliability.This paper proposed an efficient multi-layer model based on the EH concept, which is designed to systematically model the energy system and schedule energy within steelworks to meet the energy demand. Besides, to simulate the actual working conditions of the energy devices, the method of fitting the curve is used to describe the efficiency of the energy devices. Moreover, to evaluate the applicability of the proposed model, a case study is conducted to minimize both the economic operation cost and CO_2 emissions. The optimal results demonstrated that the model is suitable for energy systems within steel works. Further, the economic operation cost decreased by 3.41%, and CO_2 emissions decreased by approximately 3.67%.
基金supported by the Research and Development of Key Technologies of the Regional Energy Internet based on Multi-Energy Complementary and Collaborative Optimization(BE2020081)。
文摘Multi-energy microgrids(MEMG)play an important role in promoting carbon neutrality and achieving sustainable development.This study investigates an effective energy management strategy(EMS)for MEMG.First,an energy management system model that allows for intra-microgrid energy conversion is developed,and the corresponding Markov decision process(MDP)problem is formulated.Subsequently,an improved double deep Q network(iDDQN)algorithm is proposed to enhance the exploration ability by modifying the calculation of the Q value,and a prioritized experience replay(PER)is introduced into the iDDQN to improve the training speed and effectiveness.Finally,taking advantage of the federated learning(FL)and iDDQN algorithms,a federated iDDQN is proposed to design an MEMG energy management strategy to enable each microgrid to share its experiences in the form of local neural network(NN)parameters with the federation layer,thus ensuring the privacy and security of data.The simulation results validate the superior performance of the proposed energy management strategy in minimizing the economic costs of the MEMG while reducing CO_2 emissions and protecting data privacy.
基金supported by State Grid Corporation Technology Project (5400-201956447A-0-0-00)。
文摘In a multi-energy collaboration system, cooling, heating, electricity, and other energy components are coupled to complement each other. Through multi-energy coordination and cooperation, they can significantly improve their individual operating efficiency and overall economic benefits. Demand response, as a multi-energy supply and demand balance method, can further improve system flexibility and economy. Therefore, a multi-energy cooperative system optimization model has been proposed, which is driven by price-based demand response to determine the impact of power-demand response on the optimal operating mode of a multi-energy cooperative system. The main components of the multi-energy collaborative system have been analyzed. The multi-energy coupling characteristics have been identified based on the energy hub model. Using market elasticity as a basis, a price-based demand response model has been built. The model has been optimized to minimize daily operating cost of the multi-energy collaborative system. Using data from an actual situation, the model has been verified, and we have shown that the adoption of price-based demand response measures can significantly improve the economy of multi-energy collaborative systems.
基金funded by two projects of Science and Technology Commission of Shanghai Municipality,Grant Nos.20DZ1206300,18DZ1203304,18DZ1203403.
文摘The temporal and spatial characteristics of seasonal hydrogen storage will play a very important role in the coupling of multi-energy systems.This essay believes that there are several key issues worth noting in the seasonal hydrogen storage coupled multi-energy system,namely,hydrogen storage methods,coupling models,and benefit evaluation.Through research,this article innovatively divides seasonal hydrogen storage into two types:space transfer hydrogen storage technology and time transfer physical property conversion hydrogen storage technology.Then sort out the two most typical seasonal hydrogen storage multi-energy system application scenarios and their hydrogen storage unit models.Finally,it is shown that hydrogen storage methods should be selected according to different periods of time and regions,and the benefits should be evaluated before they can be used in practice.This review study is applicable to the process of coupling seasonal hydrogen storage in multi-energy systems.Hydrogen energy is used as an intermediate energy link for the selection,evaluation and modeling of the optimal selection and rational utilization.
基金supported by the Science and Technology Project of State Grid Corporation of China.
文摘In the background of the large-scale development and utilization of renewable energy,the joint operation of a variety of heterogeneous energy sources has become an inevitable development trend.However,the physical characteristics of different power sources and the inherent uncertainties of renewable energy power generation have brought difficulties to the planning,operation and control of power systems.For now,the utilization of multi-energy complementarity to promote energy transformation and improve the consumption of renewable energy has become a common understanding among researchers and the engineering community.This paper makes a review of the research on complementarity of new energy high proportion multi-energy systems from uncertainty modeling,complementary characteristics,planning and operation.We summarize the characteristics of the existing research and provide a reference for the further work.
基金National High Technology Research and Development Program"863"(No.2001AA501012)
文摘In order to solve the core issue of the energy regulation （ER） on multi-energy resource powertrain of fuel cell vehicle, the work functions of each component were defined; the mathematical algorithm model of energy regulation was established and the relevant solution was found. This algorithm was evaluated successfully on the hardware in loop （FILL） platform under three typical urban running cycles. The results showed ER control target had been realized and the mathematical algorithm was effective and reasonable. Based on the HIL simulation, some conclusions and ER strategies were made. According to the different power component parameters and real time control request, this algorithm should be modified and calibrated for application in the actual control system.
文摘Multi-energy flow (MEF) coupling is one of the key features of the energy Internet and integrated energy systems that are different from smart grids. With the increasing coupling of heterogeneous energy flow, the system characteristics of coupling are becoming more and more obvious and more complicated. The modeling, analysis and control methods of traditional single flow systems have not been applied directly. Therefore, it is necessary to study the modeling of multi-energy flow coupling, the power flow analysis, optimization and control method of heterogeneous energy flow, which plays the role of multi-energy flow synergy to avoid the adverse effects of coupling. This paper summarizes the current research situation of energy Internet at home and abroad from the aspects of modeling of multi-energy flow, power flow calculation and optimal dispatching, and analyzes the existing problems in the research of these aspects.
文摘The multi-energy complementary distributed energy system (MCDES) covers a variety of energy forms, involves complex operation modes, and contains a wealth of control equipment and coupling links. It can realize the complementary and efficient use of different types of energy, which is the basic component of the physical layer of the Energy Internet. In this paper, aiming at the demand of the energy application for towns, a distributed energy system based on multi-energy complementary is constructed. Firstly, the supply condition of the distributed energy for the demonstration project is analyzed, and the architecture of the multi-energy complementary distributed energy system is established. Then the regulation strategy of the multi-energy complementary distributed energy system is proposed. Finally, an overall system scheme for the multi-energy complementary distributed energy system suitable for towns is developed, which provides a solid foundation for the development and promotion of the multi-energy complementary distributed energy system.
文摘We present a non-destructive method (NDM) to identify minute quantities of high atomic number (<em>Z</em>) elements in containers such as passenger baggage, goods carrying transport trucks, and environmental samples. This method relies on the fact that photon attenuation varies with its energy and properties of the absorbing medium. Low-energy gamma-ray intensity loss is sensitive to the atomic number of the absorbing medium, while that of higher-energies vary with the density of the medium. To verify the usefulness of this feature for NDM, we carried out simultaneous measurements of intensities of multiple gamma rays of energies 81 to 1408 keV emitted by sources<sup> 133</sup>Ba (half-life = 10.55 y) and <sup>152</sup>Eu (half-life = 13.52 y). By this arrangement, we could detect minute quantities of lead and copper in a bulk medium from energy dependent gamma-ray attenuations. It seems that this method will offer a reliable, low-cost, low-maintenance alternative to X-ray or accelerator-based techniques for the NDM of high-Z materials such as mercury, lead, uranium, and transuranic elements etc.
基金supported by the National Natural Science Foundation of China(No.52205468,No.52275431,No.52375186)China Postdoctoral Science Foundation(No.2025M771349)Zhejiang Province Natural Science Foundation(No.LD22E050001)。
文摘The latest generation of aero engines has set higher standards for thrust-to-weight ratio and energy conversion efficiency,making it imperative to address the challenge of efficiently and accurately machining film cooling holes.It has been demonstrated that conventional long-pulse lasers are incapable of meeting the elevated quality surface finish requirements for these holes,a consequence of the severe thermal defects.The employment of backside water-assisted laser drilling technology confers a number of distinct advantages in terms of mitigating laser thermal damage,thus representing a highly promising solution to this challenge.However,significant accumulation of bubbles and machining products during the backside water-assisted laser drilling process has been demonstrated to have a detrimental effect on laser transmission and machining stability,thereby reducing machining quality.In order to surmount these challenges,a novel method has been proposed,namely an ultrasonic shock water flow-assisted picosecond laser drilling technique.Numerical models for ultrasonic acoustic streaming and particle tracking for machining product transport have been established to investigate the mechanism.The simulation results demonstrated that the majority of the machining products could rapidly move away from the machining area because of the action of acoustic streaming,thereby avoiding the accumulation of bubbles and products.Subsequent analysis,comparing the process performance in micro-hole machining,confirmed that the ultrasonic field could effectively eliminate bubble and chip accumulation,thus significantly improving micro-hole quality.Furthermore,the impact of ultrasonic and laser parameters on micro-hole quality under varying machining methods was thoroughly investigated.The findings demonstrated that the novel methodology outlined in this study yielded superior-quality micro-holes at elevated ultrasonic and laser power levels,in conjunction with reduced laser frequency and scanning velocity.The taper of the micro-holes produced by the new method was reduced by more than 25%compared with the other conventional methods.
基金supported by the National Key Research and Development Program of China(2018YFA0702200)National Natural Science Foundation of China(No.62073065).
文摘Generally,energy trading in smart grid is realized by microgrids.Correspondingly,energy trading in energy internet relies on small-scale energy systems,named as Weenergies(WEs).Previous works on the distributed energy trading focused on the trading platform or trading mechanism based on distributed communication.However,most ignored the fact that there is no express delivery of energy trading,and the transmission of energy depends on a fixed physical topology.Energy transactions without considering the transmission distance will increase the difficulty of energy scheduling and the transmission cost of energy.Aiming at this problem,an aggregation game among WEs is proposed for two-way multi-energy trading,and a distributed algorithm is designed to solve the Nash equilibrium.Since each WE only needs to communicate with its neighbors to exchange information,this distributed process reduces communication burden and improves information security.Furthermore,a multi-energy transmission optimization model is established to determine the transmission path of the transmission energy,which can minimize the transmission cost.Subsequently,to reduce the influence of real-time fluctuations of renewable energy and load,a receding horizon control algorithm is designed to improve the reliability of the proposed game.Finally,the effectiveness in dealing with two-way multi-energy trading of the proposed strategy is verified through simulations on the five connected WEs.
基金supported by the Joint Key Project of National Natural Science Foundation of China(UU23A20649).
文摘Mesh-constructed and radial-operated features call for elaborate consideration of co-planning for multi-energy distribution systems(MEDS).Considering a reconfiguration channel can be constructed in advance to cope with extreme N-1 contingencies,this paper proposes a hierarchical robust expansion co-planning model for MEDS.By adopting convex hull relaxation and linearization techniques,the model is cast as a mixed-integer linear programming(MILP)problem with high accuracy.Specifically,the model is divided into four parts:master investment problem,feasible load cutting subproblem in normal scenarios or N-1 fault scenarios,and optimal operational subproblem.Based on defense-attack-correction methodology,a hierarchical solution incorporating adjustable N-1 contingency tolerance is developed to trade-off economy and reliability.Furthermore,a relaxation feedback method is applied to solve invalid feedback cuts of existing parameterization methods.Numerical test results justify the model can generate the best configuration for mesh-constructed MEDS,and the reconfiguration strategy under different adjustable N-1 contingency tolerances is also given as an output of the optimization.
基金supported by the National Natural Science Foundation of China(Grant 52177110)JC STEM Lab of Future Energy Systems(Grant 2025-0039)+1 种基金Global STEM Professorship(Grant GSP313)a Startup Grant of City University of Hong Kong.
文摘As a frontier topic in the field of architecture,multi-energy building systems hold great significance in balancing the relationship among energy,environment and economy,as well as in promoting the green-and low-carbon transformation of the construction industry.This study proposes a low-carbon scheduling strategy incorporating electricity-carbon incentive compensation.Firstly,a theoretical model of multi-energy buildings is established,enabling the coordinated regulation of distributed electricity-cooling-heating energy conversion devices to improve the energy utilisation efficiency and reduce both integrated operational and carbon trading expenses.Meanwhile,a price transmission model of electricity-carbon market is developed by combining a tiered carbon pricing scheme with reward-penalty attributes and the Chinese certified emissions reduction(CCER)mechanism,thereby facilitating system optimisation and effective control of carbon emissions.Furthermore,a multi-stakeholder game strategy with electricity-carbon incentive compensation is introduced to stimulate active engagement in energy conservation and carbon emissions reduction across various stakeholders within the system.The simulation results indicate that the proposed theoretical framework has significant advantages in enhancing the economic performance of multienergy building systems,curtailing operational expense and expanding carbon market profit,demonstrating the great potential and value for the low-carbon operation of the system to be applied and widely promoted.
基金supported by National Natural Science Foundation of China(U24B6010).
文摘Anomaly detection is crucial for data-driven applications in integrated energy systems.Traditional anomaly detection methods primarily focus on one single energy load,often neglecting potential spatial correlations between multivariate energy time series.Meanwhile,addressing the imbalanced nature of user-level multi-en-ergy load data remains a significant challenge.In this paper,we propose EGBAD,an Ensemble Graph-Boosted Anomaly Detection framework for user-level multi-energy load that leverages the advantages of graph relational analysis and ensemble learning.First,a dynamic graph construction method based on multidimensional scaling(MDS)is proposed to transform multi-energy load data into graph representations.These graphs are subse-quently processed using graph convolutional network(GCN)to capture the spatiotemporal correlations between multi-energy load time series.In addition,to improve detection robustness under class imbalance,the entire training process is embedded within a Boosting ensemble learning framework,where the weight assigned to the minority class is progressively increased at each boosting stage.Experimental results on publicly real-world datasets demonstrate that the proposed model achieves superior anomaly detection accuracy compared to most baseline methods.Notably,it performs especially well in scenarios characterized by extreme data imbal-ance,achieving the highest recall and F1-score for anomaly detection.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant No.XDA29010500)。
文摘The application of multi-energy hybrid power systems is conducive to tackling global warming and the low-carbon transition of the power system.A capacity allocation model of a multi-energy hybrid power system including wind power,solar power,energy storage,and thermal power was developed in this study.The evaluation index was defined as the objective function,formulated by normalizing the output fluctuation,economic cost,and carbon dioxide emissions.Calculations under different initial conditions and output electric power scenarios were carried out with genetic algorithm.The capacity allocation model was validated with the literature results,with errors of less than 5%.Results indicate that the capacity allocation modes of the multi-energy hybrid power system can be divided into thermal power dominated mode,multi-energy complementary mode,and renewable power dominated mode.In addition,the division of capacity allocation modes is not affected by the weather conditions and energy storage ratio.The capacity factor decreases from 0.4 to 0.24 as the power system changes from the thermal power dominated mode to the renewable power dominated mode.When the output electric power is 240 MW,300 MW,and 340 MW,the optimal energy storage ratio is 10%,18%,and 16%,respectively.The model developed in this study not only enriches the theory of multi-energy complementary power generation but also guides the engineering design of the wind-photovoltaics-thermal-storage system targeting smart grid and be beneficial for the middle-long-term planning of the green and low-carbon transition of the power system.
基金supported by the Major Program of the National Natural Science Foundation of China(Grant No.52090060)。
文摘Multi-energy complementary distributed energy system(MECDES)is an important development direction for the energy system.It has the advantages of energy conservation and environmental protection and has great potential to realize efficient energy cascade utilization through the energy conversion and utilization of cooling,heating,and power in place,achieving a user-oriented energy supply.The present study thoroughly reviews the current research status and puts forward the key scientific issues that urgently need to be resolved by investigating the problems and challenges of the MECDES from the perspectives of the characterization of the energetic mass-energy potential,the synergistic transformation and energy-potential coupling mechanism of multi-energy complementation,energy quality improvement and storage,and proactive regulation of the MECDES.Furthermore,the latest research progress of the MECDES for trickling the key scientific issues is comprehensively presented by proposing the distributed energy system with the complementation of multi-energy sources,developing novel ways of the energy potential coupling and energy cascaded comprehensive utilization of multi-energy complementation,proposing a new theory of multi-energy complementation and energy potential coupling and a new mechanism of source complementation,processing matching and thermodynamic cycle system collaborative conversion of both the fossil energy and renewable energy,and developing a new method of proactive adjust and control for adapting to fluctuating energy input and various energy load demands.Finally,the prospects and recommendations for the future research and development direction of MECDES are provided.
