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
Under the current long-term electricity market mechanism,new energy and thermal power face issues such as deviation assessment and compression of generation space.The profitability of market players is limited.Simulta...Under the current long-term electricity market mechanism,new energy and thermal power face issues such as deviation assessment and compression of generation space.The profitability of market players is limited.Simultaneously,the cooperation model among various energy sources will have a direct impact on the alliance’s revenue and the equity of income distribution within the alliance.Therefore,integrating new energy with thermal power units into an integrated multi-energy complementary system to participate in the long-term electricity market holds significant potential.To simulate and evaluate the benefits and internal distribution methods of a multi-energy complementary system participating in long-term market transactions,this paper first constructs a multi-energy complementary system integrated with new energy and thermal power generation units at the same connection point,and participates in the annual bilateral game as a unified market entity to obtain the revenue value under the annual bilateral market.Secondly,based on the entropy weight method,improvements are made to the traditional Shapley value distribution model,and an internal distribution model for multi-energy complementary systems with multiple participants is constructed.Finally,a Markov Decision Process(MDP)evaluation system is constructed for practical case verification.The research results show that the improved Shapley value distribution model achieves higher satisfaction,providing a reasonable allocation scheme for multi-energy complementary cooperation models.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
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
The isolated hybrid AC/DC multi-energy microgrid(IH-MEMG)offers an effective solution for meeting the electrical,heating,and cooling energy demands of remote and off-grid areas.For an IH-MEMG,system transient dynamics...The isolated hybrid AC/DC multi-energy microgrid(IH-MEMG)offers an effective solution for meeting the electrical,heating,and cooling energy demands of remote and off-grid areas.For an IH-MEMG,system transient dynamics(i.e.,frequency or voltage of the electricity network)and economics are critical aspects that pose the greatest concern to operators.However,these aspects are generally investigated separately owing to their different time scales.To integrate these aspects from the scope of real-time control,this study proposes a bi-layer coordinated power regulation strategy considering system dynamics and economics for the IH-MEMG.First,coupling relationships among multiple sub-networks are analyzed,and a frequency-voltage coupling model between the AC and DC sides is established.Then,a bi-layer coordinated power regulation strategy is developed for the IH-MEMG with output characteristics of different components involved:the primary layer includes a multi-entity power support mechanism used to improve the dynamics of the electricity network,wherein a cooperation principle of the combined cooling,heating,and power(CCHP)unit and energy storage unit(ESU)is designed in detailed;meanwhile,the secondary layer includes a real-time economics-oriented optimization framework used to adjust the power references of multiple units generated from the primary layer for cost efficiency improvement(notably,the primary layer can work independently).Finally,the effectiveness of the proposed strategy is verified through comprehensive simulations under varying operation scenarios.展开更多
With the rapid growth of photovoltaic integration,the volatility and uncertainty of intermittent photovoltaic injection will dramatically reduce system operation reliability from the generation side.The system operato...With the rapid growth of photovoltaic integration,the volatility and uncertainty of intermittent photovoltaic injection will dramatically reduce system operation reliability from the generation side.The system operator may face certain financial risks brought by unexpected power failure under low operation reliability.Therefore,maintaining sufficient power reserve to meet system operation reliability and reduce risk,especially in an isolated system,is essential.However,the traditional reserve preparation strategy fails to consider the uncertainties of the power generation under the high penetration levels of emerging renewable energy resources.A novel reserve preparation strategy for an isolated system is developed in this paper using a twostage model.In the first stage,the optimal hourly scheduling of an isolated system is determined.In the second stage,a minute level conditional value-at-risk(CVaR)based model is established where the uncertainty of the reserve requirement is introduced with the chance constraint.The proposed discretized step transformation(DST)and subtraction type convolution(STC)methods are utilized to convert the model into mixedinteger linear programming,and finally solved by applying the CPLEX solver.The IEEE 39-bus system is used as the test case to validate the feasibility and effectiveness of the proposed two-stage model.展开更多
The multi-energy complementary ecosystem is an important form of the modern energy system.However,standardized evaluation criteria and the corresponding method framework have not yet been formed,resulting in unclear s...The multi-energy complementary ecosystem is an important form of the modern energy system.However,standardized evaluation criteria and the corresponding method framework have not yet been formed,resulting in unclear standards and irregular processes of its construction.To cope with this issue,a novel comprehensive evaluation framework for multi-energy complementary ecosystems is proposed in this study.First,a 5D comprehensive evaluation criteria system,including environment,economy,technology,safety and systematicness,is constructed.Then,a novel multicriteria decision-making model integrating an analytic network process,entropy and preference-ranking organization method for enrichment evaluation under an intuitional fuzzy environment is proposed.Finally,four practical cases are used for model testing and empirical analysis.The results of the research show that the unit cost of the energy supply and the internal rate of return indexes have the highest weights of 0.142 and 0.010,respectively.It means that they are the focus in the construction of a multi-energy complementary ecosystem.The net flows of four cases are 0.015,0.123,-0.132 and-0.005,indicating that cases with a variety of energy supply forms and using intelligent management and control platforms to achieve cold,heat and electrical coupling have more advantages.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
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.
文摘Under the current long-term electricity market mechanism,new energy and thermal power face issues such as deviation assessment and compression of generation space.The profitability of market players is limited.Simultaneously,the cooperation model among various energy sources will have a direct impact on the alliance’s revenue and the equity of income distribution within the alliance.Therefore,integrating new energy with thermal power units into an integrated multi-energy complementary system to participate in the long-term electricity market holds significant potential.To simulate and evaluate the benefits and internal distribution methods of a multi-energy complementary system participating in long-term market transactions,this paper first constructs a multi-energy complementary system integrated with new energy and thermal power generation units at the same connection point,and participates in the annual bilateral game as a unified market entity to obtain the revenue value under the annual bilateral market.Secondly,based on the entropy weight method,improvements are made to the traditional Shapley value distribution model,and an internal distribution model for multi-energy complementary systems with multiple participants is constructed.Finally,a Markov Decision Process(MDP)evaluation system is constructed for practical case verification.The research results show that the improved Shapley value distribution model achieves higher satisfaction,providing a reasonable allocation scheme for multi-energy complementary cooperation models.
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.
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.
基金supported by the International Science and Technology Cooperation Program of China(Grant No.2022YFE0129300)the National Natural Science Foundation of China(Grant Nos.U22B20104,52277090,52207097)+2 种基金the Science and Technology Innovation Program of Hunan Province(Grant No.2023RC3102)the Excellent Innovation Youth Program of Changsha of China(Grant No.kq2209010)the Key Research and Development Program of Hunan Province(Grant No.2023GK2007)。
文摘The isolated hybrid AC/DC multi-energy microgrid(IH-MEMG)offers an effective solution for meeting the electrical,heating,and cooling energy demands of remote and off-grid areas.For an IH-MEMG,system transient dynamics(i.e.,frequency or voltage of the electricity network)and economics are critical aspects that pose the greatest concern to operators.However,these aspects are generally investigated separately owing to their different time scales.To integrate these aspects from the scope of real-time control,this study proposes a bi-layer coordinated power regulation strategy considering system dynamics and economics for the IH-MEMG.First,coupling relationships among multiple sub-networks are analyzed,and a frequency-voltage coupling model between the AC and DC sides is established.Then,a bi-layer coordinated power regulation strategy is developed for the IH-MEMG with output characteristics of different components involved:the primary layer includes a multi-entity power support mechanism used to improve the dynamics of the electricity network,wherein a cooperation principle of the combined cooling,heating,and power(CCHP)unit and energy storage unit(ESU)is designed in detailed;meanwhile,the secondary layer includes a real-time economics-oriented optimization framework used to adjust the power references of multiple units generated from the primary layer for cost efficiency improvement(notably,the primary layer can work independently).Finally,the effectiveness of the proposed strategy is verified through comprehensive simulations under varying operation scenarios.
文摘With the rapid growth of photovoltaic integration,the volatility and uncertainty of intermittent photovoltaic injection will dramatically reduce system operation reliability from the generation side.The system operator may face certain financial risks brought by unexpected power failure under low operation reliability.Therefore,maintaining sufficient power reserve to meet system operation reliability and reduce risk,especially in an isolated system,is essential.However,the traditional reserve preparation strategy fails to consider the uncertainties of the power generation under the high penetration levels of emerging renewable energy resources.A novel reserve preparation strategy for an isolated system is developed in this paper using a twostage model.In the first stage,the optimal hourly scheduling of an isolated system is determined.In the second stage,a minute level conditional value-at-risk(CVaR)based model is established where the uncertainty of the reserve requirement is introduced with the chance constraint.The proposed discretized step transformation(DST)and subtraction type convolution(STC)methods are utilized to convert the model into mixedinteger linear programming,and finally solved by applying the CPLEX solver.The IEEE 39-bus system is used as the test case to validate the feasibility and effectiveness of the proposed two-stage model.
基金supported by the second batch of the soft subject research project of China Southern Power Grid Corporation in 2022,‘Exploring the construction path of multi energy complementary ecosystem of industrial parks in Qianhai’(XNXM_20221209003).
文摘The multi-energy complementary ecosystem is an important form of the modern energy system.However,standardized evaluation criteria and the corresponding method framework have not yet been formed,resulting in unclear standards and irregular processes of its construction.To cope with this issue,a novel comprehensive evaluation framework for multi-energy complementary ecosystems is proposed in this study.First,a 5D comprehensive evaluation criteria system,including environment,economy,technology,safety and systematicness,is constructed.Then,a novel multicriteria decision-making model integrating an analytic network process,entropy and preference-ranking organization method for enrichment evaluation under an intuitional fuzzy environment is proposed.Finally,four practical cases are used for model testing and empirical analysis.The results of the research show that the unit cost of the energy supply and the internal rate of return indexes have the highest weights of 0.142 and 0.010,respectively.It means that they are the focus in the construction of a multi-energy complementary ecosystem.The net flows of four cases are 0.015,0.123,-0.132 and-0.005,indicating that cases with a variety of energy supply forms and using intelligent management and control platforms to achieve cold,heat and electrical coupling have more advantages.
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.
