To address the issue of coordinated control of multiple hydrogen and battery storage units to suppress the grid-injected power deviation of wind farms,an online optimization strategy for Battery-hydrogen hybrid energy...To address the issue of coordinated control of multiple hydrogen and battery storage units to suppress the grid-injected power deviation of wind farms,an online optimization strategy for Battery-hydrogen hybrid energy storage systems based on measurement feedback is proposed.First,considering the high charge/discharge losses of hydrogen storage and the low energy density of battery storage,an operational optimization objective is established to enable adaptive energy adjustment in the Battery-hydrogen hybrid energy storage system.Next,an online optimization model minimizing the operational cost of the hybrid system is constructed to suppress grid-injected power deviations with satisfying the operational constraints of hydrogen storage and batteries.Finally,utilizing the online measurement of the energy states of hydrogen storage and batteries,an online optimization strategy based on measurement feedback is designed.Case study results show:before and after smoothing the fluctuations in wind power,the time when the power exceeded the upper and lower limits of the grid-injected power accounted for 24.1%and 1.45%of the total time,respectively,the proposed strategy can effectively keep the grid-injected power deviations of wind farms within the allowable range.Hydrogen storage and batteries respectively undertake long-term and short-term charge/discharge tasks,effectively reducing charge/discharge losses of the Battery-hydrogen hybrid energy storage systems and improving its operational efficiency.展开更多
Introduction of vacancies is a widely practiced method to improve the performance of active materials in differentenergy systems, such as secondary batteries, electrocatalysis, and supercapacitors. Because vacancies c...Introduction of vacancies is a widely practiced method to improve the performance of active materials in differentenergy systems, such as secondary batteries, electrocatalysis, and supercapacitors. Because vacancies can generateabundant localized electrons and unsaturated cations, the incorporation of vacancies will significantly improvethe electrical conductivity, ion migration, and provides additional active sites of energy storage materials. Thisarticle systematically reviews different methods to generate oxygen, nitrogen, or selenium vacancies, and techniques to characterize these vacancies. We summarize the specific roles that vacancies play for the active materials in each type of energy storage devices. Additionally, we provide insights into the research progress andchallenges associated with the future development of vacancies technology in various energy storage systems.展开更多
The economic operation of integrated energy system(IES)faces new challenges such as multi-timescale characteristics of heterogeneous energy sources,and cooperative operation of hybrid energy storage system(HESS).To th...The economic operation of integrated energy system(IES)faces new challenges such as multi-timescale characteristics of heterogeneous energy sources,and cooperative operation of hybrid energy storage system(HESS).To this end,this paper investigates the multi-timescale rolling opti-mization problem for IES integrated with HESS.Firstly,the architecture of IES with HESS is established,a comparative analysis is conducted to evaluate the advantages of the HESS over a single energy storage system(SESS)in stabilizing power fluctuations.Secondly,the dayahead and real-time scheduling cost functions of IES are established,the day-ahead scheduling mainly depends on operation costs of the components in IES,the real-time optimal scheduling adopts the Lya-punov optimization method to schedule the battery and hydrogen energy storage in each time slot,so as to minimize the real-time average scheduling operation cost,and the problem of day-ahead and real-time scheduling error,which caused by the uncertainty of the energy storage is solved by online optimization.Finally,the proposed model is verified to reduce the scheduling operation cost and the dispatching error by performing an arithmetic example analysis of the IES in Shanghai,which provides a reference for the safe and stable operation of the IES.展开更多
Energy in its varied forms and applications has become the main driver of today’s modern society. However, recent changes in power demand and climatic changes (decarbonization policy) has awakened the need to rethink...Energy in its varied forms and applications has become the main driver of today’s modern society. However, recent changes in power demand and climatic changes (decarbonization policy) has awakened the need to rethink through the current energy generating and distribution system. This led to the exploration of other energy sources of which renewable energy (like thermal, solar and wind energy) is fast becoming an integral part of most energy system. However, this innovative and promising energy source is highly unreliable in maintaining a constant peak power that matches demand. Energy storage systems have thus been highlighted as a solution in managing such imbalances and maintaining the stability of supply. Energy storage technologies absorb and store energy, and release it on demand. This includes gravitational potential energy (pumped hydroelectric), chemical energy (batteries), kinetic energy (flywheels or compressed air), and energy in the form of electrical (capacitors) and magnetic fields. This paper provides a detailed and comprehensive overview of some of the state-of-the-art energy storage technologies, its evolution, classification, and comparison along with various area of applications. Also highlighted in this paper is a plethora of power electronic Interface technologies that plays a significant role in enabling optimum performance and utilization of energy storage systems in different areas of application.展开更多
随着电动汽车的大规模入网,其无序充电使得负荷峰谷差距进一步激增,给电力系统的稳定运行带来了负面影响,因此提出1种计及电动汽车负荷和电池储能系统的削峰填谷两阶段优化调度策略。首先,以用户充电成本和负荷绝对峰谷差最小为目标建...随着电动汽车的大规模入网,其无序充电使得负荷峰谷差距进一步激增,给电力系统的稳定运行带来了负面影响,因此提出1种计及电动汽车负荷和电池储能系统的削峰填谷两阶段优化调度策略。首先,以用户充电成本和负荷绝对峰谷差最小为目标建立电动汽车有序充电调度模型,利用改进粒子群优化算法对模型进行求解,促使电动汽车避峰充电;其次,以负荷方差和储能寿命综合成本最小为目标建立储能系统削峰填谷优化调度模型,采用改进哈里斯鹰优化HHO(Harris Hawks optimization)算法对模型进行求解,从而减小负荷峰谷差,并通过削峰填谷评价指标对优化结果进行评估和分析;最后,以某电网实测负荷功率为例进行仿真实验,结果表明,所提两阶段优化调度策略使得负荷峰值降低了约147 k W,负荷谷值上升了约223 k W,峰谷差降低了约46.73%,能够有效改善负荷曲线,缓解负荷高峰期电力供应紧张的压力,保证了电网的安全、稳定运行。展开更多
The control of battery energy storage systems(BESSs)plays an important role in the management of microgrids.In this paper,the problem of balancing the state-ofcharge(SoC)of the networked battery units in a BESS while ...The control of battery energy storage systems(BESSs)plays an important role in the management of microgrids.In this paper,the problem of balancing the state-ofcharge(SoC)of the networked battery units in a BESS while meeting the total charging/discharging power requirement is formulated and solved as a distributed control problem.Conditions on the communication topology among the battery units are established under which a control law is designed for each battery unit to solve the control problem based on distributed average reference power estimators and distributed average unit state estimators.Two types of estimators are proposed.One achieves asymptotic estimation and the other achieves finite time estimation.We show that,under the proposed control laws,SoC balancing of all battery units is achieved and the total charging/discharging power of the BESS tracks the desired power.A simulation example is shown to verify the theoretical results.展开更多
Within the framework of achieving carbon neutrality,various industries are confronted with fresh challenges.The ongoing process of downsizing coal industry operations has evolved into a new phase,with the burgeoning p...Within the framework of achieving carbon neutrality,various industries are confronted with fresh challenges.The ongoing process of downsizing coal industry operations has evolved into a new phase,with the burgeoning proliferation of abandoned mines posing a persistent issue.Addressing the challenges and opportunities presented by these abandoned mines,this paper advocates for a scientific approach centered on the advancement of pumped storage energy alongside gas-oil complementary energy.Leveraging abandoned mine tunnels to establish pumped storage power stations holds significant ecological and economic importance for repurposing these sites.This initiative not only serves as an effective means to restore the ecological balance in mining regions but also provides an environmentally friendly approach to repurposing abandoned mine tunnels,offering a blueprint for economically viable pumped storage power stations.This article delineates five crucial scientific considerations and outlines seven primary models for the utilization of abandoned mine sites,delineating a novel,comprehensive pathway for energy and power development that emphasizes multi-energy complementarity and synergistic optimization within abandoned mines.展开更多
A smart grid will require, to greater or lesser degrees, advanced tools for planning and operation, broadly accepted communications platforms, smart sensors and controls, and real-time pricing. The smart grid has been...A smart grid will require, to greater or lesser degrees, advanced tools for planning and operation, broadly accepted communications platforms, smart sensors and controls, and real-time pricing. The smart grid has been described as something of an ecosystem with constantly communication, proactive, and virtually self-aware. The use of smart grid has a lot of economical and environmental advantages;however it has a downside of instability and unpredictability introduced by distributed generation (DG) from renewable energy into the public electric systems. Variable energies such as solar and wind power have a lack of stability and to avoid short-term fluctuations in power supplied to the grid, a local storage subsystem could be used to provide higher quality and stability in the fed energy. Energy storage systems (ESSs) would be a facilitator of smart grid deployment and a “small amount” of storage would have a “great impact” on the future power grid. The smart grid, with its various superior communications and control features, would make it possible to integrate the potential application of widely dispersed battery storage systems as well other ESSs. This work deals with a detailed updated review on available ESSs applications in future smart power grids. It also highlights latest projects carried out on different ESSs throughout all around the world.展开更多
Present-day power conversion and conditioning systems focus on transferring energy from a single type of power source into a single type of load or energy storage system (ESS). While these systems can be optimized wit...Present-day power conversion and conditioning systems focus on transferring energy from a single type of power source into a single type of load or energy storage system (ESS). While these systems can be optimized within their specific topology (e.g. MPPT for solar applications and BMS for batteries), the topologies are not easily adapted to accept a wide range of power flow operating conditions. With a hybrid approach to energy storage and power flow, a system can be designed to operate at its most advantageous point, given the operating conditions. Based on the load demand, the system can select the optimal power source and ESS. This paper will investigate the feasibility of combining two types of power sources (main utility grid and photovoltaics (PV)) along with two types of ESS (ultra-capacitors and batteries). The simulation results will show the impact of a hybrid ESS on a grid-tied residential microgrid system performance under various operating scenarios.展开更多
Variable distributed energy resources (DERs) such as photovoltaic (PV) systems and wind power systems require additional power resources to control the balance between supply and demand. Battery energy storage systems...Variable distributed energy resources (DERs) such as photovoltaic (PV) systems and wind power systems require additional power resources to control the balance between supply and demand. Battery energy storage systems (BESSs) are one such possible resource for providing grid stability. It has been proposed that decentralized BESSs could help support microgrids (MGs) with intelligent control when advanced functionalities are implemented with variable DERs. One key challenge is developing and testing smart inverter controls for DERs. This paper presents a standardized method to test the interoperability and functionality of BESSs. First, a survey of grid-support standards prevalent in several countries was conducted. Then, the following four interoperability functions defined in IEC TR 61850-90-7 were tested: the specified active power from storage test (INV4), the var-priority Volt/VAR test (VV) and the specified power factor test (INV3) and frequency-watt control (FW). This study then out-lines the remaining technical issues related to basic BESS smart inverter test protocols.展开更多
The German Aerospace Center has merged a wide range of technological research and development for future cars in a project called ＂Next Generation Car＂. Within this large research project, three vehicle concepts for...The German Aerospace Center has merged a wide range of technological research and development for future cars in a project called ＂Next Generation Car＂. Within this large research project, three vehicle concepts for different applications （urban, regional and interurban） and with different powertrains （fuel-cell, battery and hybrid） will be developed. Research questions on different levels from conceptual question about vehicle modularity down to detailed technological aspects like combining hydrogen storage with cabin climatization and a systematic investigation of different thermal energy storage systems for electric vehicles concepts are covered by this project. To the latter, the contribution shows an overview about three thermal storage technologies--sensible solid media, metallic latent and thermochemical thermal energy storage systems--and details about the development of an electrically heated （power-to-heat） solid media storage system to achieve high storage densities and to allow flexible thermal discharging values. Central works target the identification of suitable thermal management solutions in future electric vehicle concepts to increase range, efficiency and flexibility.展开更多
In this paper, an extended analysis of the performance of different hybrid Rechargeable Energy Storage Systems (RESS) for use in Plug-in Hybrid Electric Vehicle (PHEV) with a series drivetrain topology is analyzed, ba...In this paper, an extended analysis of the performance of different hybrid Rechargeable Energy Storage Systems (RESS) for use in Plug-in Hybrid Electric Vehicle (PHEV) with a series drivetrain topology is analyzed, based on simulations with three different driving cycles. The investigated hybrid energy storage topologies are an energy optimized lithium-ion battery (HE) in combination with an Electrical Double-Layer Capacitor (EDLC) system, in combination with a power optimized lithium-ion battery (HP) system or in combination with a Lithium-ion Capacitor (LiCap) system, that act as a Peak Power System. From the simulation results it was observed that hybridization of the HE lithium-ion based energy storage system resulted from the three topologies in an increased overall energy efficiency of the RESS, in an extended all electric range of the PHEV and in a reduced average current through the HE battery. The lowest consumption during the three driving cycles was obtained for the HE-LiCap topology, where fuel savings of respectively 6.0%, 10.3% and 6.8% compared with the battery stand-alone system were achieved. The largest extension of the range was achieved for the HE-HP configuration (17% based on FTP-75 driving cycle). HP batteries however have a large internal resistance in comparison to EDLC and LiCap systems, which resulted in a reduced overall energy efficiency of the hybrid RESS. Additionally, it was observed that the HP and LiCap systems both offer significant benefits for the integration of a peak power system in the drivetrain of a Plug-in Hybrid Electric Vehicle due to their low volume and weight in comparison to that of the EDLC system.展开更多
When the capacitor cell is discharged in the short-circuit mode, the current pulse amplitude and duration are maximal. Therefore, this mode is the most severe for discharge switches of capacitive energy storage. The c...When the capacitor cell is discharged in the short-circuit mode, the current pulse amplitude and duration are maximal. Therefore, this mode is the most severe for discharge switches of capacitive energy storage. The characteristics of the transient process of the discharge capacitive energy storage and the current loads acting in the facility discharge circuit have been defined for this mode. The test bench for definition of the LTT(Light Triggered Thyristors) loading capacity is described. The limiting characteristics have been experimentally obtained for LTT, at which there emerges the thermo-generation peak.The process of OFF-ON switching of LTTs has been investigated, the necessity is shown to use the speedup R-C circuits to ensure fast and stable transition of LTT into the conducting state. The design of the switch unit for the capacitive energy storage comprising LTTs and crowbar diodes is described, and the transient processes of current switching in crowbar diodes are considered. The tests carried out during switching of pul se current up to 100 kA at a voltage of 6 kV have confirmed the workability of the switch unit.展开更多
A two-dimensional unsteady heat transfer model of pavement of geothermal road snow-melting system (GRSS) with solar energy storage is established and numerical simulation is carried out based on annual hourly meteorol...A two-dimensional unsteady heat transfer model of pavement of geothermal road snow-melting system (GRSS) with solar energy storage is established and numerical simulation is carried out based on annual hourly meteorological data and boundary conditions. Simulated results show that ground surface temperature and heating flux decrease with the increase of buried depth, but increase with the increase of fluid temperature in winter. Heat-extracted amount and efficiency drop with the increase of fluid temperature in summer.Compared with ambient temperature, solar radiation has more direct influence on the heat-extracted flux of pipe walls of GRSS in summer. The relationships among maximum and idling snow-melting load, the rate of snowfall, ambient temperature and wind speed are made clear, which provides necessary references for the design and optimization of a practical road snow-melting system.展开更多
Demand response(DR)using shared energy storage systems(ESSs)is an appealing method to save electricity bills for users under demand charge and time-of-use(TOU)price.A novel Stackelberg-game-based ESS sharing scheme is...Demand response(DR)using shared energy storage systems(ESSs)is an appealing method to save electricity bills for users under demand charge and time-of-use(TOU)price.A novel Stackelberg-game-based ESS sharing scheme is proposed and analyzed in this study.In this scheme,the interactions between selfish users and an operator are characterized as a Stackelberg game.Operator holds a large-scale ESS that is shared among users in the form of energy transactions.It sells energy to users and sets the selling price first.It maximizes its profit through optimal pricing and ESS dispatching.Users purchase some energy from operator for the reduction of their demand charges after operator's selling price is announced.This game-theoretic ESS sharing scheme is characterized and analyzed by formulating and solving a bi-level optimization model.The upper-level optimization maximizes operator's profit and the lower-level optimization minimizes users'costs.The bi-level model is transformed and linearized into a mixed-integer linear programming(MILP)model using the mathematical programming with equilibrium constraints(MPEC)method and model linearizing techniques.Case studies with actual data are carried out to explore the economic performances of the proposed ESS sharing scheme.展开更多
The conceptual design of the capacitive energy storage intended for operation in laboratory conditions is considered. This capacitive energy storage includes the capacitor cells of 200 kJ stored energy, each incorpora...The conceptual design of the capacitive energy storage intended for operation in laboratory conditions is considered. This capacitive energy storage includes the capacitor cells of 200 kJ stored energy, each incorporating one self-healing high-energy-density capacitor, one semiconducting switch unit on the basis of Light Triggered Thyristors(LTT) and the pulse diodes, as well as the toroid inductor. Power supply of the capacitive energy storage is provided by high voltage(HV) 3 x 10 kV, 50 Hz industrial electrical network, using the HV power transformer and phase-controlled rectifier. Special design for the capacitor cell and the module of capacitor cells is proposed, which provides easy access to all components of the capacitor cells during operation and maintenance. Control system of the capacitive energy system has a hierarchic structure and includes programmable logic controller(PLC), programmer for non-synchronous triggering of capacitor cells discharges and data acquisition system.展开更多
For flow batteries(FBs), the current technologies are still expensive and have relatively low energy density, which limits their large-scale applications. Organic FBs(OFBs) which employ organic molecules as redox-acti...For flow batteries(FBs), the current technologies are still expensive and have relatively low energy density, which limits their large-scale applications. Organic FBs(OFBs) which employ organic molecules as redox-active materials have been considered as one of the promising technologies for achieving lowcost and high-performance. Herein, we present a critical overview of the progress on the OFBs, including the design principles of key components(redox-active molecules, membranes, and electrodes) and the latest achievement in both aqueous and nonaqueous systems. Finally, future directions in explorations of the high-performance OFB for electrochemical energy storage are also highlighted.展开更多
基金Supported by State Grid Zhejiang Electric Power Co.,Ltd.Science and Technology Project Funding(No.B311DS230005).
文摘To address the issue of coordinated control of multiple hydrogen and battery storage units to suppress the grid-injected power deviation of wind farms,an online optimization strategy for Battery-hydrogen hybrid energy storage systems based on measurement feedback is proposed.First,considering the high charge/discharge losses of hydrogen storage and the low energy density of battery storage,an operational optimization objective is established to enable adaptive energy adjustment in the Battery-hydrogen hybrid energy storage system.Next,an online optimization model minimizing the operational cost of the hybrid system is constructed to suppress grid-injected power deviations with satisfying the operational constraints of hydrogen storage and batteries.Finally,utilizing the online measurement of the energy states of hydrogen storage and batteries,an online optimization strategy based on measurement feedback is designed.Case study results show:before and after smoothing the fluctuations in wind power,the time when the power exceeded the upper and lower limits of the grid-injected power accounted for 24.1%and 1.45%of the total time,respectively,the proposed strategy can effectively keep the grid-injected power deviations of wind farms within the allowable range.Hydrogen storage and batteries respectively undertake long-term and short-term charge/discharge tasks,effectively reducing charge/discharge losses of the Battery-hydrogen hybrid energy storage systems and improving its operational efficiency.
基金supported by the National Natural Science Foundation of China(No.52372176)Sichuan Science and Technology Program(2023YFH0026).
文摘Introduction of vacancies is a widely practiced method to improve the performance of active materials in differentenergy systems, such as secondary batteries, electrocatalysis, and supercapacitors. Because vacancies can generateabundant localized electrons and unsaturated cations, the incorporation of vacancies will significantly improvethe electrical conductivity, ion migration, and provides additional active sites of energy storage materials. Thisarticle systematically reviews different methods to generate oxygen, nitrogen, or selenium vacancies, and techniques to characterize these vacancies. We summarize the specific roles that vacancies play for the active materials in each type of energy storage devices. Additionally, we provide insights into the research progress andchallenges associated with the future development of vacancies technology in various energy storage systems.
基金supported by the National Natural Science Foundation of China(No.12171145)。
文摘The economic operation of integrated energy system(IES)faces new challenges such as multi-timescale characteristics of heterogeneous energy sources,and cooperative operation of hybrid energy storage system(HESS).To this end,this paper investigates the multi-timescale rolling opti-mization problem for IES integrated with HESS.Firstly,the architecture of IES with HESS is established,a comparative analysis is conducted to evaluate the advantages of the HESS over a single energy storage system(SESS)in stabilizing power fluctuations.Secondly,the dayahead and real-time scheduling cost functions of IES are established,the day-ahead scheduling mainly depends on operation costs of the components in IES,the real-time optimal scheduling adopts the Lya-punov optimization method to schedule the battery and hydrogen energy storage in each time slot,so as to minimize the real-time average scheduling operation cost,and the problem of day-ahead and real-time scheduling error,which caused by the uncertainty of the energy storage is solved by online optimization.Finally,the proposed model is verified to reduce the scheduling operation cost and the dispatching error by performing an arithmetic example analysis of the IES in Shanghai,which provides a reference for the safe and stable operation of the IES.
文摘Energy in its varied forms and applications has become the main driver of today’s modern society. However, recent changes in power demand and climatic changes (decarbonization policy) has awakened the need to rethink through the current energy generating and distribution system. This led to the exploration of other energy sources of which renewable energy (like thermal, solar and wind energy) is fast becoming an integral part of most energy system. However, this innovative and promising energy source is highly unreliable in maintaining a constant peak power that matches demand. Energy storage systems have thus been highlighted as a solution in managing such imbalances and maintaining the stability of supply. Energy storage technologies absorb and store energy, and release it on demand. This includes gravitational potential energy (pumped hydroelectric), chemical energy (batteries), kinetic energy (flywheels or compressed air), and energy in the form of electrical (capacitors) and magnetic fields. This paper provides a detailed and comprehensive overview of some of the state-of-the-art energy storage technologies, its evolution, classification, and comparison along with various area of applications. Also highlighted in this paper is a plethora of power electronic Interface technologies that plays a significant role in enabling optimum performance and utilization of energy storage systems in different areas of application.
文摘随着电动汽车的大规模入网,其无序充电使得负荷峰谷差距进一步激增,给电力系统的稳定运行带来了负面影响,因此提出1种计及电动汽车负荷和电池储能系统的削峰填谷两阶段优化调度策略。首先,以用户充电成本和负荷绝对峰谷差最小为目标建立电动汽车有序充电调度模型,利用改进粒子群优化算法对模型进行求解,促使电动汽车避峰充电;其次,以负荷方差和储能寿命综合成本最小为目标建立储能系统削峰填谷优化调度模型,采用改进哈里斯鹰优化HHO(Harris Hawks optimization)算法对模型进行求解,从而减小负荷峰谷差,并通过削峰填谷评价指标对优化结果进行评估和分析;最后,以某电网实测负荷功率为例进行仿真实验,结果表明,所提两阶段优化调度策略使得负荷峰值降低了约147 k W,负荷谷值上升了约223 k W,峰谷差降低了约46.73%,能够有效改善负荷曲线,缓解负荷高峰期电力供应紧张的压力,保证了电网的安全、稳定运行。
基金relates to Department of Navy award(N00014-20-1-2858)。
文摘The control of battery energy storage systems(BESSs)plays an important role in the management of microgrids.In this paper,the problem of balancing the state-ofcharge(SoC)of the networked battery units in a BESS while meeting the total charging/discharging power requirement is formulated and solved as a distributed control problem.Conditions on the communication topology among the battery units are established under which a control law is designed for each battery unit to solve the control problem based on distributed average reference power estimators and distributed average unit state estimators.Two types of estimators are proposed.One achieves asymptotic estimation and the other achieves finite time estimation.We show that,under the proposed control laws,SoC balancing of all battery units is achieved and the total charging/discharging power of the BESS tracks the desired power.A simulation example is shown to verify the theoretical results.
基金Project(202208340045)supported by the China Scholarship Council FundProject(U21A20110)supported by the Regional Innovation and Development Joint Fund of National Natural Science Foundation of China+1 种基金Project(EUCMR202201)supported by the Open Project Program of Anhui Engineering Research Center of Exploitation and Utilization of Closed/abandoned Mine Resources,ChinaProject(2023cxcyzx063)supported by the Anhui Province New Era Talent Education Project,China。
文摘Within the framework of achieving carbon neutrality,various industries are confronted with fresh challenges.The ongoing process of downsizing coal industry operations has evolved into a new phase,with the burgeoning proliferation of abandoned mines posing a persistent issue.Addressing the challenges and opportunities presented by these abandoned mines,this paper advocates for a scientific approach centered on the advancement of pumped storage energy alongside gas-oil complementary energy.Leveraging abandoned mine tunnels to establish pumped storage power stations holds significant ecological and economic importance for repurposing these sites.This initiative not only serves as an effective means to restore the ecological balance in mining regions but also provides an environmentally friendly approach to repurposing abandoned mine tunnels,offering a blueprint for economically viable pumped storage power stations.This article delineates five crucial scientific considerations and outlines seven primary models for the utilization of abandoned mine sites,delineating a novel,comprehensive pathway for energy and power development that emphasizes multi-energy complementarity and synergistic optimization within abandoned mines.
文摘A smart grid will require, to greater or lesser degrees, advanced tools for planning and operation, broadly accepted communications platforms, smart sensors and controls, and real-time pricing. The smart grid has been described as something of an ecosystem with constantly communication, proactive, and virtually self-aware. The use of smart grid has a lot of economical and environmental advantages;however it has a downside of instability and unpredictability introduced by distributed generation (DG) from renewable energy into the public electric systems. Variable energies such as solar and wind power have a lack of stability and to avoid short-term fluctuations in power supplied to the grid, a local storage subsystem could be used to provide higher quality and stability in the fed energy. Energy storage systems (ESSs) would be a facilitator of smart grid deployment and a “small amount” of storage would have a “great impact” on the future power grid. The smart grid, with its various superior communications and control features, would make it possible to integrate the potential application of widely dispersed battery storage systems as well other ESSs. This work deals with a detailed updated review on available ESSs applications in future smart power grids. It also highlights latest projects carried out on different ESSs throughout all around the world.
文摘Present-day power conversion and conditioning systems focus on transferring energy from a single type of power source into a single type of load or energy storage system (ESS). While these systems can be optimized within their specific topology (e.g. MPPT for solar applications and BMS for batteries), the topologies are not easily adapted to accept a wide range of power flow operating conditions. With a hybrid approach to energy storage and power flow, a system can be designed to operate at its most advantageous point, given the operating conditions. Based on the load demand, the system can select the optimal power source and ESS. This paper will investigate the feasibility of combining two types of power sources (main utility grid and photovoltaics (PV)) along with two types of ESS (ultra-capacitors and batteries). The simulation results will show the impact of a hybrid ESS on a grid-tied residential microgrid system performance under various operating scenarios.
文摘Variable distributed energy resources (DERs) such as photovoltaic (PV) systems and wind power systems require additional power resources to control the balance between supply and demand. Battery energy storage systems (BESSs) are one such possible resource for providing grid stability. It has been proposed that decentralized BESSs could help support microgrids (MGs) with intelligent control when advanced functionalities are implemented with variable DERs. One key challenge is developing and testing smart inverter controls for DERs. This paper presents a standardized method to test the interoperability and functionality of BESSs. First, a survey of grid-support standards prevalent in several countries was conducted. Then, the following four interoperability functions defined in IEC TR 61850-90-7 were tested: the specified active power from storage test (INV4), the var-priority Volt/VAR test (VV) and the specified power factor test (INV3) and frequency-watt control (FW). This study then out-lines the remaining technical issues related to basic BESS smart inverter test protocols.
文摘The German Aerospace Center has merged a wide range of technological research and development for future cars in a project called ＂Next Generation Car＂. Within this large research project, three vehicle concepts for different applications （urban, regional and interurban） and with different powertrains （fuel-cell, battery and hybrid） will be developed. Research questions on different levels from conceptual question about vehicle modularity down to detailed technological aspects like combining hydrogen storage with cabin climatization and a systematic investigation of different thermal energy storage systems for electric vehicles concepts are covered by this project. To the latter, the contribution shows an overview about three thermal storage technologies--sensible solid media, metallic latent and thermochemical thermal energy storage systems--and details about the development of an electrically heated （power-to-heat） solid media storage system to achieve high storage densities and to allow flexible thermal discharging values. Central works target the identification of suitable thermal management solutions in future electric vehicle concepts to increase range, efficiency and flexibility.
文摘In this paper, an extended analysis of the performance of different hybrid Rechargeable Energy Storage Systems (RESS) for use in Plug-in Hybrid Electric Vehicle (PHEV) with a series drivetrain topology is analyzed, based on simulations with three different driving cycles. The investigated hybrid energy storage topologies are an energy optimized lithium-ion battery (HE) in combination with an Electrical Double-Layer Capacitor (EDLC) system, in combination with a power optimized lithium-ion battery (HP) system or in combination with a Lithium-ion Capacitor (LiCap) system, that act as a Peak Power System. From the simulation results it was observed that hybridization of the HE lithium-ion based energy storage system resulted from the three topologies in an increased overall energy efficiency of the RESS, in an extended all electric range of the PHEV and in a reduced average current through the HE battery. The lowest consumption during the three driving cycles was obtained for the HE-LiCap topology, where fuel savings of respectively 6.0%, 10.3% and 6.8% compared with the battery stand-alone system were achieved. The largest extension of the range was achieved for the HE-HP configuration (17% based on FTP-75 driving cycle). HP batteries however have a large internal resistance in comparison to EDLC and LiCap systems, which resulted in a reduced overall energy efficiency of the hybrid RESS. Additionally, it was observed that the HP and LiCap systems both offer significant benefits for the integration of a peak power system in the drivetrain of a Plug-in Hybrid Electric Vehicle due to their low volume and weight in comparison to that of the EDLC system.
文摘When the capacitor cell is discharged in the short-circuit mode, the current pulse amplitude and duration are maximal. Therefore, this mode is the most severe for discharge switches of capacitive energy storage. The characteristics of the transient process of the discharge capacitive energy storage and the current loads acting in the facility discharge circuit have been defined for this mode. The test bench for definition of the LTT(Light Triggered Thyristors) loading capacity is described. The limiting characteristics have been experimentally obtained for LTT, at which there emerges the thermo-generation peak.The process of OFF-ON switching of LTTs has been investigated, the necessity is shown to use the speedup R-C circuits to ensure fast and stable transition of LTT into the conducting state. The design of the switch unit for the capacitive energy storage comprising LTTs and crowbar diodes is described, and the transient processes of current switching in crowbar diodes are considered. The tests carried out during switching of pul se current up to 100 kA at a voltage of 6 kV have confirmed the workability of the switch unit.
基金Supported by Tianjin Science and Technology Development Foundation(No.013112811-1).
文摘A two-dimensional unsteady heat transfer model of pavement of geothermal road snow-melting system (GRSS) with solar energy storage is established and numerical simulation is carried out based on annual hourly meteorological data and boundary conditions. Simulated results show that ground surface temperature and heating flux decrease with the increase of buried depth, but increase with the increase of fluid temperature in winter. Heat-extracted amount and efficiency drop with the increase of fluid temperature in summer.Compared with ambient temperature, solar radiation has more direct influence on the heat-extracted flux of pipe walls of GRSS in summer. The relationships among maximum and idling snow-melting load, the rate of snowfall, ambient temperature and wind speed are made clear, which provides necessary references for the design and optimization of a practical road snow-melting system.
基金supported by the National Natural Science Foundation of China(U21A20478)Zhejiang Provincial Nature Science Foundation of China(LZ21F030004)Key-Area Research and Development Program of Guangdong Province(2018B010107002)。
文摘Demand response(DR)using shared energy storage systems(ESSs)is an appealing method to save electricity bills for users under demand charge and time-of-use(TOU)price.A novel Stackelberg-game-based ESS sharing scheme is proposed and analyzed in this study.In this scheme,the interactions between selfish users and an operator are characterized as a Stackelberg game.Operator holds a large-scale ESS that is shared among users in the form of energy transactions.It sells energy to users and sets the selling price first.It maximizes its profit through optimal pricing and ESS dispatching.Users purchase some energy from operator for the reduction of their demand charges after operator's selling price is announced.This game-theoretic ESS sharing scheme is characterized and analyzed by formulating and solving a bi-level optimization model.The upper-level optimization maximizes operator's profit and the lower-level optimization minimizes users'costs.The bi-level model is transformed and linearized into a mixed-integer linear programming(MILP)model using the mathematical programming with equilibrium constraints(MPEC)method and model linearizing techniques.Case studies with actual data are carried out to explore the economic performances of the proposed ESS sharing scheme.
文摘The conceptual design of the capacitive energy storage intended for operation in laboratory conditions is considered. This capacitive energy storage includes the capacitor cells of 200 kJ stored energy, each incorporating one self-healing high-energy-density capacitor, one semiconducting switch unit on the basis of Light Triggered Thyristors(LTT) and the pulse diodes, as well as the toroid inductor. Power supply of the capacitive energy storage is provided by high voltage(HV) 3 x 10 kV, 50 Hz industrial electrical network, using the HV power transformer and phase-controlled rectifier. Special design for the capacitor cell and the module of capacitor cells is proposed, which provides easy access to all components of the capacitor cells during operation and maintenance. Control system of the capacitive energy system has a hierarchic structure and includes programmable logic controller(PLC), programmer for non-synchronous triggering of capacitor cells discharges and data acquisition system.
基金supported by the China Natural Science Foundation(U1808209)the CAS-DOE program,CAS(QYZDB-SSWJSC032)+1 种基金the Key R&D project of Dalian(2018YF17GX020)the DICP funding(ZZBS201707)。
文摘For flow batteries(FBs), the current technologies are still expensive and have relatively low energy density, which limits their large-scale applications. Organic FBs(OFBs) which employ organic molecules as redox-active materials have been considered as one of the promising technologies for achieving lowcost and high-performance. Herein, we present a critical overview of the progress on the OFBs, including the design principles of key components(redox-active molecules, membranes, and electrodes) and the latest achievement in both aqueous and nonaqueous systems. Finally, future directions in explorations of the high-performance OFB for electrochemical energy storage are also highlighted.
