China has become the world’s largest producer and consumer of energy,and ranks first in its wind and solar power installation capacity.However,serious wind and solar curtailment in China has significantly hindered th...China has become the world’s largest producer and consumer of energy,and ranks first in its wind and solar power installation capacity.However,serious wind and solar curtailment in China has significantly hindered the development and utilization of renewable energy.To address problems in the consumption of renewable energy,this paper analyzes four key factors affecting the capacity of power generated from renewable energy sources:power balance,power regulation performance,transmission capacity,and load level.Focusing on these bottlenecks,we propose seven solutions:centralized and distributed development of renewable energy,improving the peak-load regulation flexibility of thermal power,increasing the proportion of gas turbines and pumped-hydropower storage,construction of transmission channels and a flexible smart grid developing demand response and virtual power plants,adopting new energy active support and energy storage,and establishing appropriate policies and market mechanisms.The Chinese Government and energy authorities have issued a series of policies and measures,and in the past three years,China has had remarkable achievements in the adoption of renewable energy.The rate of idle wind capacity decreased from 17%in 2016 to 7%in 2018,and that of solar decreased from 10%in 2016 to 3%in 2018.展开更多
1.Introduction Climate change has become a global nontraditional security challenge,and achieving carbon neutrality is the global trend of the era that will determine the future of humanity[1-5].So far,more than 137 c...1.Introduction Climate change has become a global nontraditional security challenge,and achieving carbon neutrality is the global trend of the era that will determine the future of humanity[1-5].So far,more than 137 countries have set goals or pledged to achieve carbon neutrality.In September 2020,China committed itself to peak carbon emissions by 2030 and to achieve carbon neutrality by 2060,in what are known as China’s“dual carbon goals”[6].展开更多
A power source–power grid coordinated typhoon defense strategy is proposed in this study to minimize the cost of power grid anti-typhoon reinforcement measures and improve defense efficiency.It is based on multiagent...A power source–power grid coordinated typhoon defense strategy is proposed in this study to minimize the cost of power grid anti-typhoon reinforcement measures and improve defense efficiency.It is based on multiagent dynamic game theory.This strategy regards a typhoon as a rational gamer that always causes the greatest damage.Together with the grid planner and black start unit(BSU)planner,it forms a multiagent defense–attack–defense dynamic game model naturally.The model is adopted to determine the optimal reinforcements for the transmission lines,black start power capacity,and location.Typhoon Hato,which struck a partial coastal area in Guangdong province in China in 2017,was adopted to formulate a step-by-step model of a typhoon attacking coastal area power systems.The results were substituted into the multiagent defense–attack–defense dynamic game model to obtain the optimal transmission line reinforcement positions,as well as optimal BSU capacity and geographic positions.An effective typhoon defense strategy and minimum load shedding were achieved,demonstrating the feasibility and correctness of the proposed strategy.The related theories and methods of this study have positive significance for the prevention of uncertain large-scale natural disasters.展开更多
Power plants are nonlinear and uncertain complex systems. Reliable control of superheated steam temperature is necessary to ensure high efficiency and high load-following capability in the operation of modem power pla...Power plants are nonlinear and uncertain complex systems. Reliable control of superheated steam temperature is necessary to ensure high efficiency and high load-following capability in the operation of modem power plant. A nonlinear generalized predictive controller based on neuro-fuzzy network （NFGPC） is proposed in this paper. The proposed nonlinear controller is applied to control the superheated steam temperature of a 200MW power plant. From the experiments on the plant and the simulation of the plant, much better performance than the traditional controller is obtained,展开更多
Boiler fan is the main power consumption device in thermal power units and the induced draft fan accounted for the largest proportion. Reducing the energy consumption rate of induced draft fan is the main path to redu...Boiler fan is the main power consumption device in thermal power units and the induced draft fan accounted for the largest proportion. Reducing the energy consumption rate of induced draft fan is the main path to reduce the power consumption rate of thermal power units. The induce fan driven by small turbine is greatly effective for reducing the power consumption rate and the supply coal consumption rate in large thermal power plant. Take 1000 MW power units for example, the selection of steam source for steam turbine were discussed and economic performance of the unit under different steam source was compared in this paper. The result shows that compared with the motor driven method, there is about 1.6 g/kWh decrease in supply coal consumption rate driven by the fourth stage extraction steam;whereas there is about 2.5 g/kWh decrease in supply coal consumption rate driven by the fifth stage extraction steam.展开更多
Valve management is one of the major functions of DEH for steam turbine. It has an important practical significance for the security and economy of the steam turbine. This paper starts from the valve configuration fig...Valve management is one of the major functions of DEH for steam turbine. It has an important practical significance for the security and economy of the steam turbine. This paper starts from the valve configuration figure of the domestic-type 300 MW steam turbine, and then makes a simple comparison between the two types of valve governing modes. In order to realize the valve control, the structure of control system has been established, in which the roles of the mathematical functions are discussed. On the basis of the experiment of valve flow characteristic, this article carries out a quantitative study on the functions of the valve management and the parameter tuning method. Through a serious corrections, the sequence valve flow characteristic curve is obtained, which can provide significant guidance on the research of valve management of the similar steam turbines.展开更多
The authors regret to inform that the first author should change to Yinao Su,and would like to add an author Haixia Huang to the author list.The correct order of the authors should be Yinao Su,Houliang Dai,Lichun Kuan...The authors regret to inform that the first author should change to Yinao Su,and would like to add an author Haixia Huang to the author list.The correct order of the authors should be Yinao Su,Houliang Dai,Lichun Kuang,Jizhen Liu,Dazhao Gu,Caineng Zou,and Haixia Huang.The authors would like to apologize for any inconvenience caused.展开更多
With the popularization of wind energy, the further reduction of power generation cost became the critical problem. As to improve the efficiency of control for variable speed Wind Turbine Generation System (WTGS), the...With the popularization of wind energy, the further reduction of power generation cost became the critical problem. As to improve the efficiency of control for variable speed Wind Turbine Generation System (WTGS), the data-driven Adaptive Neuro-Fuzzy Inference System (ANFIS) was used to establish a sensorless wind speed estimator. Moreover, based on the Supervisory Control and Data Acquisition (SCADA) System, the optimum setting strategy for the maximum energy capture was proposed for the practical operation process. Finally, the simulation was executed which suggested the effectiveness of the approaches.展开更多
Hybrid energy storage system(HESS)is an effective way to mitigate wind power fluctuations on multi-time scale,and can improve influence of large-scale grid-connected wind power on stability and reliability of power sy...Hybrid energy storage system(HESS)is an effective way to mitigate wind power fluctuations on multi-time scale,and can improve influence of large-scale grid-connected wind power on stability and reliability of power system.A novel methodology named zero-phase controlled auto-regressive integrated moving-average(CARIMA)filter is proposed to integrate HESS to smooth wind power fluctuations.First,a design method for zero-phase CARIMA filter is provided,and then used to determine grid-connected power for a wind storage system and size HESS.The reasons,direct current(DC)component caused by energy storage efficiency and grid-connected power delay caused by phase shift,for causing superfluous energy storage configuration are revealed.In addition,a nonlinear programming scheduling strategy considering battery degradation is proposed.Power imbalance caused by efficiency difference during dynamic adjustment of energy storage output power is addressed.Furthermore,thermostatically controlled loads(TCLs)are integrated in sizing and scheduling HESS to reduce energy storage demand and improve operating conditions of energy storage.Finally,effectiveness of the proposed strategy is verified by a case study.展开更多
Frequency stability and security have been a vital challenge as large-scale renewable energy is integrated into power systems.In contrast,the proportion of traditional thermal power units decreases during the decarbon...Frequency stability and security have been a vital challenge as large-scale renewable energy is integrated into power systems.In contrast,the proportion of traditional thermal power units decreases during the decarbonization transformation process,resulting in poor frequency support.This paper aims to explore the potential of frequency regulation support,dynamic assessment,and capacity promotion of thermal power plants in the transition period.Considering the dynamic characteristics of the main steam working fluid under different working conditions,a nonlinear observer is constructed by extracting the main steam pressure and valve opening degree parameters.The real-time frequency modulation capacity of thermal power units can provide a dynamic state for the power grid.A dynamic adaptive modification for primary frequency control(PFC)of power systems,including wind power and thermal power,is proposed and improved.The power dynamic allocation factor is adaptively optimized by predicting the speed droop ratio,and the frequency modulation capability of the system is improved by more than 11%under extreme conditions.Finally,through the Monte Carlo simulation of unit states of the system under various working conditions,the promotion of the frequency regulation capacity with high wind power penetration(WPP)is verified.展开更多
The stochastic fluctuation of renewable energy resources has significant impact on the stability of the power system with renewable generations and results in change in stability.Therefore,it is necessary to track the...The stochastic fluctuation of renewable energy resources has significant impact on the stability of the power system with renewable generations and results in change in stability.Therefore,it is necessary to track the changing stability of the power system with renewable generations,a task that can be performed online.This paper details the use of decision trees to predict multi-mode damping of power system integrating renewable generations with the help of wide-area measurements system(WAMS).Power systems with renewable source generation are complex with vast amounts of data being collected from WAMS.Decision trees(DTs)are employed as a means to handle vast quantities of wide-area information,which involves the mode damping information indicating the stability.A 16-generator,68-bus system with photovoltaic power generation and wind power generation is used as the test system.Remote signals obtained from phasor measurement units(PMUs)are employed as the input variables of DTs for predicting purposes.The simulation results demonstrate that the proposed predicting scheme is able to suggest the optimal course of action to remedy any near instability or unstable electromechanical oscillations even without prior knowledge of the varying output of the renewable source power.展开更多
An approach to smoothing the fluctuations of largescale wind power is investigated using vehicle-to-grid(V2G)systems.First,an energy management and optimization system is designed and modeled.By using the wavelet pack...An approach to smoothing the fluctuations of largescale wind power is investigated using vehicle-to-grid(V2G)systems.First,an energy management and optimization system is designed and modeled.By using the wavelet packet decomposition method,the target grid-connected wind power,the required electric vehicle(EV)power,and supercapacitor power are determined.The energy management model for EVs is then developed by introducing a knapsack problem that can evaluate the needs of an EV fleet.Furthermore,an optimized dispatch strategy for EVs and wind power is developed by using a dynamic programming method.A case study demonstrates that the energy management and optimization method for V2G systems achieves noticeable performance improvements over benchmark techniques.展开更多
Large fluctuations may occur on the energy supply and the load sides when large-scale renewable energies are integrated,leading to great challenges in power systems.The renewable power curtailment is especially numero...Large fluctuations may occur on the energy supply and the load sides when large-scale renewable energies are integrated,leading to great challenges in power systems.The renewable power curtailment is especially numerous in the integrated electricity-heat energy system(IEHES)on account of electricity-heat coupling.The flexible resources(FRs)on both the energy supply and load sides are introduced into the optimal dispatch of the IEHES and further modeled to alleviate the renewable fluctuations in this paper.On the energy supply side,three kinds of FRs based on electricity-heat coordination are modeled and discussed.On the load side,the shiftable electricity demand resource is characterized.On this basis,the solution for FRs participating in IEHES dispatch is given,with goals of maximizing the renewable penetration ratio and lowering operation costs.Two scenarios are performed,and the results indicate that the proposed optimal dispatch strategy can effectively reduce the renewable energy curtailment and improve the flexibility of the IEHES.The contribution degrees of different FRs for renewable integration are also explored.展开更多
Microgrids(MGs)are playing a fundamental role in the transition of energy systems towards a low carbon future due to the advantages of a highly efficient network architecture for flexible integration of various DC/AC ...Microgrids(MGs)are playing a fundamental role in the transition of energy systems towards a low carbon future due to the advantages of a highly efficient network architecture for flexible integration of various DC/AC loads,distributed renewable energy sources,and energy storage systems,as well as a more resilient and economical on/off-grid control,operation,and energy management.However,MGs,as newcomers to the utility grid,are also facing challenges due to economic deregulation of energy systems,restructuring of generation,and marketbased operation.This paper comprehensively summarizes the published research works in the areas of MGs and related energy management modelling and solution techniques.First,MGs and energy storage systems are classified into multiple branches and typical combinations as the backbone of MG energy management.Second,energy management models under exogenous and endogenous uncertainties are summarized and extended to transactive energy management.Mathematical programming,adaptive dynamic programming,and deep reinforcement learning-based solution methods are investigated accordingly,together with their implementation schemes.Finally,problems for future energy management systems with dynamics-captured critical component models,stability constraints,resilience awareness,market operation,and emerging computational techniques are discussed.展开更多
In this work,neodymium(Nd)and samarium(Sm)codoped lead lanthanum zirconate titanate(PLZT)ceramics were prepared by a high-temperature solid-state method.The samples were characterized by X-ray diffraction,scanning ele...In this work,neodymium(Nd)and samarium(Sm)codoped lead lanthanum zirconate titanate(PLZT)ceramics were prepared by a high-temperature solid-state method.The samples were characterized by X-ray diffraction,scanning electron microscopy and ferroelectric analysis.Rare earth-doped PLZT ceramics show good phase formation.An appropriate rare earth element doping amount increases the densities of PLZT ceramics and reduces their resistivities,which is due to the role of rare earth elements in grain refinement.However,the increase in the amount of grain boundaries caused by grain refinement also affects domain inversion.Therefore,with increasing doping concentration,the remnant polarization of PLZT gradually decreases,and the doping of rare earth elements also slightly reduces the band gap of PLZT.Under irradiation with an X-ray simulated beta source with a particle energy of 10 keV(between the average energies of the beta particles of^3H and^(63)Ni),the ceramic sheets in this work produce current densities of up to 1.38 nA/cm^2.This indicates that Nd and Sm codoped PLZT ceramics have a certain potential for application in betavoltaic batteries.展开更多
Wind power curve modeling is essential in the analysis and control of wind turbines(WTs),and data preprocessing is a critical step in accurate curve modeling.As traditional methods do not sufficiently consider WT mode...Wind power curve modeling is essential in the analysis and control of wind turbines(WTs),and data preprocessing is a critical step in accurate curve modeling.As traditional methods do not sufficiently consider WT models,this paper proposes a new data cleaning method for wind power curve modeling.In this method,a model-data hybrid-driven(MDHD)outlier detection method is constructed,and an adaptive update rule for major parameters in the detection algorithm is designed based on the WT model.Simultaneously,because the MDHD outlier detection method considers multiple types of operating data of WTs,anomaly detection results require further analysis.Accordingly,an expert system is developed in which a knowledgebase and an inference engine are designed based on the coupling relationships of different operating data.Finally,abnormal data are eliminated and the power curve modeling is completed.The proposed and traditional methods are compared in numerical cases,and the superiority of the proposed method is demonstrated.展开更多
基金The work was supported in part by the consulting research project of Chinese Academy of Engineering(2017-XY-16)in part by the National Natural Science Foundation of China(52061635102).
文摘China has become the world’s largest producer and consumer of energy,and ranks first in its wind and solar power installation capacity.However,serious wind and solar curtailment in China has significantly hindered the development and utilization of renewable energy.To address problems in the consumption of renewable energy,this paper analyzes four key factors affecting the capacity of power generated from renewable energy sources:power balance,power regulation performance,transmission capacity,and load level.Focusing on these bottlenecks,we propose seven solutions:centralized and distributed development of renewable energy,improving the peak-load regulation flexibility of thermal power,increasing the proportion of gas turbines and pumped-hydropower storage,construction of transmission channels and a flexible smart grid developing demand response and virtual power plants,adopting new energy active support and energy storage,and establishing appropriate policies and market mechanisms.The Chinese Government and energy authorities have issued a series of policies and measures,and in the past three years,China has had remarkable achievements in the adoption of renewable energy.The rate of idle wind capacity decreased from 17%in 2016 to 7%in 2018,and that of solar decreased from 10%in 2016 to 3%in 2018.
文摘1.Introduction Climate change has become a global nontraditional security challenge,and achieving carbon neutrality is the global trend of the era that will determine the future of humanity[1-5].So far,more than 137 countries have set goals or pledged to achieve carbon neutrality.In September 2020,China committed itself to peak carbon emissions by 2030 and to achieve carbon neutrality by 2060,in what are known as China’s“dual carbon goals”[6].
基金supported by the National Natural Science Foundation of China(No.U1766204)。
文摘A power source–power grid coordinated typhoon defense strategy is proposed in this study to minimize the cost of power grid anti-typhoon reinforcement measures and improve defense efficiency.It is based on multiagent dynamic game theory.This strategy regards a typhoon as a rational gamer that always causes the greatest damage.Together with the grid planner and black start unit(BSU)planner,it forms a multiagent defense–attack–defense dynamic game model naturally.The model is adopted to determine the optimal reinforcements for the transmission lines,black start power capacity,and location.Typhoon Hato,which struck a partial coastal area in Guangdong province in China in 2017,was adopted to formulate a step-by-step model of a typhoon attacking coastal area power systems.The results were substituted into the multiagent defense–attack–defense dynamic game model to obtain the optimal transmission line reinforcement positions,as well as optimal BSU capacity and geographic positions.An effective typhoon defense strategy and minimum load shedding were achieved,demonstrating the feasibility and correctness of the proposed strategy.The related theories and methods of this study have positive significance for the prevention of uncertain large-scale natural disasters.
基金This work was supported by the Natural Science Foundation of Beijing (No. 4062030)National Natural Science Foundation of China (No. 50576022,69804003)Scientific Research Common Program of Beijing Municipal Commission of Education (KM200611232007).
文摘Power plants are nonlinear and uncertain complex systems. Reliable control of superheated steam temperature is necessary to ensure high efficiency and high load-following capability in the operation of modem power plant. A nonlinear generalized predictive controller based on neuro-fuzzy network （NFGPC） is proposed in this paper. The proposed nonlinear controller is applied to control the superheated steam temperature of a 200MW power plant. From the experiments on the plant and the simulation of the plant, much better performance than the traditional controller is obtained,
文摘Boiler fan is the main power consumption device in thermal power units and the induced draft fan accounted for the largest proportion. Reducing the energy consumption rate of induced draft fan is the main path to reduce the power consumption rate of thermal power units. The induce fan driven by small turbine is greatly effective for reducing the power consumption rate and the supply coal consumption rate in large thermal power plant. Take 1000 MW power units for example, the selection of steam source for steam turbine were discussed and economic performance of the unit under different steam source was compared in this paper. The result shows that compared with the motor driven method, there is about 1.6 g/kWh decrease in supply coal consumption rate driven by the fourth stage extraction steam;whereas there is about 2.5 g/kWh decrease in supply coal consumption rate driven by the fifth stage extraction steam.
文摘Valve management is one of the major functions of DEH for steam turbine. It has an important practical significance for the security and economy of the steam turbine. This paper starts from the valve configuration figure of the domestic-type 300 MW steam turbine, and then makes a simple comparison between the two types of valve governing modes. In order to realize the valve control, the structure of control system has been established, in which the roles of the mathematical functions are discussed. On the basis of the experiment of valve flow characteristic, this article carries out a quantitative study on the functions of the valve management and the parameter tuning method. Through a serious corrections, the sequence valve flow characteristic curve is obtained, which can provide significant guidance on the research of valve management of the similar steam turbines.
文摘The authors regret to inform that the first author should change to Yinao Su,and would like to add an author Haixia Huang to the author list.The correct order of the authors should be Yinao Su,Houliang Dai,Lichun Kuang,Jizhen Liu,Dazhao Gu,Caineng Zou,and Haixia Huang.The authors would like to apologize for any inconvenience caused.
文摘With the popularization of wind energy, the further reduction of power generation cost became the critical problem. As to improve the efficiency of control for variable speed Wind Turbine Generation System (WTGS), the data-driven Adaptive Neuro-Fuzzy Inference System (ANFIS) was used to establish a sensorless wind speed estimator. Moreover, based on the Supervisory Control and Data Acquisition (SCADA) System, the optimum setting strategy for the maximum energy capture was proposed for the practical operation process. Finally, the simulation was executed which suggested the effectiveness of the approaches.
基金supported by the Headquarters Science and Technology Project of State Grid Corporation of China(52060021N00P)。
文摘Hybrid energy storage system(HESS)is an effective way to mitigate wind power fluctuations on multi-time scale,and can improve influence of large-scale grid-connected wind power on stability and reliability of power system.A novel methodology named zero-phase controlled auto-regressive integrated moving-average(CARIMA)filter is proposed to integrate HESS to smooth wind power fluctuations.First,a design method for zero-phase CARIMA filter is provided,and then used to determine grid-connected power for a wind storage system and size HESS.The reasons,direct current(DC)component caused by energy storage efficiency and grid-connected power delay caused by phase shift,for causing superfluous energy storage configuration are revealed.In addition,a nonlinear programming scheduling strategy considering battery degradation is proposed.Power imbalance caused by efficiency difference during dynamic adjustment of energy storage output power is addressed.Furthermore,thermostatically controlled loads(TCLs)are integrated in sizing and scheduling HESS to reduce energy storage demand and improve operating conditions of energy storage.Finally,effectiveness of the proposed strategy is verified by a case study.
基金supported by the Science and Technology Project of State Grid Corporation of China(52060021N00P)。
文摘Frequency stability and security have been a vital challenge as large-scale renewable energy is integrated into power systems.In contrast,the proportion of traditional thermal power units decreases during the decarbonization transformation process,resulting in poor frequency support.This paper aims to explore the potential of frequency regulation support,dynamic assessment,and capacity promotion of thermal power plants in the transition period.Considering the dynamic characteristics of the main steam working fluid under different working conditions,a nonlinear observer is constructed by extracting the main steam pressure and valve opening degree parameters.The real-time frequency modulation capacity of thermal power units can provide a dynamic state for the power grid.A dynamic adaptive modification for primary frequency control(PFC)of power systems,including wind power and thermal power,is proposed and improved.The power dynamic allocation factor is adaptively optimized by predicting the speed droop ratio,and the frequency modulation capability of the system is improved by more than 11%under extreme conditions.Finally,through the Monte Carlo simulation of unit states of the system under various working conditions,the promotion of the frequency regulation capacity with high wind power penetration(WPP)is verified.
基金supported by the National Basic Research Program of China(973 Program)(No.2012CB215206)National Natural Science Foundation of China(No.51407071)+3 种基金the International Collaborative Project jointly Funded by the NSFC(No.51311122)Chinathe EPSRC,UKFundamental Research Funds for the Central Universities(No.2014QN18)China Postdoctoral Science Foundation(No.2014M550683).
文摘The stochastic fluctuation of renewable energy resources has significant impact on the stability of the power system with renewable generations and results in change in stability.Therefore,it is necessary to track the changing stability of the power system with renewable generations,a task that can be performed online.This paper details the use of decision trees to predict multi-mode damping of power system integrating renewable generations with the help of wide-area measurements system(WAMS).Power systems with renewable source generation are complex with vast amounts of data being collected from WAMS.Decision trees(DTs)are employed as a means to handle vast quantities of wide-area information,which involves the mode damping information indicating the stability.A 16-generator,68-bus system with photovoltaic power generation and wind power generation is used as the test system.Remote signals obtained from phasor measurement units(PMUs)are employed as the input variables of DTs for predicting purposes.The simulation results demonstrate that the proposed predicting scheme is able to suggest the optimal course of action to remedy any near instability or unstable electromechanical oscillations even without prior knowledge of the varying output of the renewable source power.
文摘An approach to smoothing the fluctuations of largescale wind power is investigated using vehicle-to-grid(V2G)systems.First,an energy management and optimization system is designed and modeled.By using the wavelet packet decomposition method,the target grid-connected wind power,the required electric vehicle(EV)power,and supercapacitor power are determined.The energy management model for EVs is then developed by introducing a knapsack problem that can evaluate the needs of an EV fleet.Furthermore,an optimized dispatch strategy for EVs and wind power is developed by using a dynamic programming method.A case study demonstrates that the energy management and optimization method for V2G systems achieves noticeable performance improvements over benchmark techniques.
基金This work was supported by the National Natural Science Foundation of China(No.52076073).
文摘Large fluctuations may occur on the energy supply and the load sides when large-scale renewable energies are integrated,leading to great challenges in power systems.The renewable power curtailment is especially numerous in the integrated electricity-heat energy system(IEHES)on account of electricity-heat coupling.The flexible resources(FRs)on both the energy supply and load sides are introduced into the optimal dispatch of the IEHES and further modeled to alleviate the renewable fluctuations in this paper.On the energy supply side,three kinds of FRs based on electricity-heat coordination are modeled and discussed.On the load side,the shiftable electricity demand resource is characterized.On this basis,the solution for FRs participating in IEHES dispatch is given,with goals of maximizing the renewable penetration ratio and lowering operation costs.Two scenarios are performed,and the results indicate that the proposed optimal dispatch strategy can effectively reduce the renewable energy curtailment and improve the flexibility of the IEHES.The contribution degrees of different FRs for renewable integration are also explored.
基金supported in part by the State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources under Grant LAPS21002in part by the National Natural Science Foundation of China under Grant 52061635102in part by Guangdong Basic and Applied Basic Research Foundation under Grant 2021A1515110583.
文摘Microgrids(MGs)are playing a fundamental role in the transition of energy systems towards a low carbon future due to the advantages of a highly efficient network architecture for flexible integration of various DC/AC loads,distributed renewable energy sources,and energy storage systems,as well as a more resilient and economical on/off-grid control,operation,and energy management.However,MGs,as newcomers to the utility grid,are also facing challenges due to economic deregulation of energy systems,restructuring of generation,and marketbased operation.This paper comprehensively summarizes the published research works in the areas of MGs and related energy management modelling and solution techniques.First,MGs and energy storage systems are classified into multiple branches and typical combinations as the backbone of MG energy management.Second,energy management models under exogenous and endogenous uncertainties are summarized and extended to transactive energy management.Mathematical programming,adaptive dynamic programming,and deep reinforcement learning-based solution methods are investigated accordingly,together with their implementation schemes.Finally,problems for future energy management systems with dynamics-captured critical component models,stability constraints,resilience awareness,market operation,and emerging computational techniques are discussed.
基金the Independent Deployment Project of Fujian Science&Technology Innovation Laboratory for Optoelectronic Information of China(2021ZZ109)the National Key Research and Development Program of China(2019YFC0605000)+2 种基金the Independent Deployment Project of Ganjiang Innovation Research Institute of Chinese Academy of Sciences(E055A002)the Key Deployment Project of the Chinese Academy of Sciences(ZDRW-CN-2021-3)the Fujian Provincial Natural Fund Project(2021J05101)。
文摘In this work,neodymium(Nd)and samarium(Sm)codoped lead lanthanum zirconate titanate(PLZT)ceramics were prepared by a high-temperature solid-state method.The samples were characterized by X-ray diffraction,scanning electron microscopy and ferroelectric analysis.Rare earth-doped PLZT ceramics show good phase formation.An appropriate rare earth element doping amount increases the densities of PLZT ceramics and reduces their resistivities,which is due to the role of rare earth elements in grain refinement.However,the increase in the amount of grain boundaries caused by grain refinement also affects domain inversion.Therefore,with increasing doping concentration,the remnant polarization of PLZT gradually decreases,and the doping of rare earth elements also slightly reduces the band gap of PLZT.Under irradiation with an X-ray simulated beta source with a particle energy of 10 keV(between the average energies of the beta particles of^3H and^(63)Ni),the ceramic sheets in this work produce current densities of up to 1.38 nA/cm^2.This indicates that Nd and Sm codoped PLZT ceramics have a certain potential for application in betavoltaic batteries.
基金supported by the Guangdong Basic and Applied Basic Research Foundation(No.2020A1515110547)Open Fund of State Key Laboratory of Operation and Control of Renewable Energy and Storage Systems(China Electric Power Research Institute)(No.NYB51202101982)。
文摘Wind power curve modeling is essential in the analysis and control of wind turbines(WTs),and data preprocessing is a critical step in accurate curve modeling.As traditional methods do not sufficiently consider WT models,this paper proposes a new data cleaning method for wind power curve modeling.In this method,a model-data hybrid-driven(MDHD)outlier detection method is constructed,and an adaptive update rule for major parameters in the detection algorithm is designed based on the WT model.Simultaneously,because the MDHD outlier detection method considers multiple types of operating data of WTs,anomaly detection results require further analysis.Accordingly,an expert system is developed in which a knowledgebase and an inference engine are designed based on the coupling relationships of different operating data.Finally,abnormal data are eliminated and the power curve modeling is completed.The proposed and traditional methods are compared in numerical cases,and the superiority of the proposed method is demonstrated.
