Electrical Energy Storage Units Research Articles

Electrical, ferroelectric and electro-caloric properties of lead-free Ba0.85Ca0.15Ti0.95(Nb0.5Yb0.5)0.05O3 multifunctional ceramic

In this study, lead-free Ba0.85Ca0.15Ti0.95(Nb0.5Yb0.5)0.05O3 (BC15TYN5) ceramic has been successfully obtained through the conventional solid-state reaction. It has been found the multifunctionality of the BC15TYN5 ceramic. It exhibits ferroelectric properties, with a significant remanent polarization value of about Pr = 9.36 μC/cm2, and a recoverable energy storage density value of about Wrec = 42.21 mJ/cm3. Additionally, it displays a dielectric permittivity of about ε′r = 7230 around TC = 80 °C, and an electro-caloric strength value of about ξ = 0.12 K mm/kV. It's worth noting that these values surpass those typically found in BaTiO3 ceramics elaborated with similar experimental conditions. Electrical study (impedance, modulus, and conductivity characteristics) is essential for characterizing the BC15TYN5 material, determining its suitability for various technological applications, and optimizing manufacturing processes. The Cole-Cole plots exhibited two relaxations associated with the contribution of the grains and grain boundaries. The relaxation times for both grains and grain boundaries showed temperature-dependent variation following Arrhenius relation. The measured AC conductivity was evaluated by applying the Jonsher power law. Based on the thermal evolution of the exponent S, it was confirmed that the conduction mechanism follows the Correlated Barrier Hopping (CBH) model. These properties make BC15TYN5 ceramic suitable for applications such as dielectric capacitors, ferroelectric random-access memories, electrical energy storage units, and electro-caloric refrigeration systems.

A distributionally robust optimization approach for optimal load dispatch of energy hub considering multiple energy storage units and demand response programs

The coupling relationship among various energy sources has been consistently reinforced by the advancement of the energy Internet. In the context of modeling multi-energy systems, the energy hub (EH) represents a significant and valuable approach. To attain optimal operation of the EH, this study proposes an optimal load dispatch model for a system that incorporates a combined heat and power (CHP) unit, gas boiler (GB), electric chiller (EC), absorption chiller (AC), heat energy storage (HES) unit, and electrical energy storage (EES) unit. A two-stage distributionally robust optimization (DRO) method that is driven by data is employed to address the uncertainties of electricity prices. Additionally, the proposed two-stage DRO model is effectively solved through the utilization of the column and constraint generation (C&CG) algorithm. Three cases are discussed in the paper with various energy storage units and demand response (DR) settings. The simulation results show that by deploying energy storage units and participating in DR projects, the EH system can reduce the total costs by 2.56 % and 10 %, respectively. Meanwhile, simulation results reveal that the proposed data-driven DRO model can achieve a compromise between the economy and robustness of the scheduling model compared with stochastic optimization (SO) and robust optimization (RO) methods. The simulation results illustrate the effectiveness of the proposed model for ensuring the economical and efficient operation of the system in the face of electricity price uncertainties.

Optimal operation of lithium-ion batteries in microgrids using a semidefinite thermal model

The growing adoption of microgrids necessitates efficient management of electrical energy storage units to ensure reliable and sustainable power supply. This paper investigates a thermal management system (TMS) for maintaining the longevity of large-scale batteries. To streamline the thermal modeling of batteries, the McCormick relaxation method is employed to linearize a nonlinear and interdependent heat generation model. The thermal model of the battery follows a nonlinear behavior where the generated heat makes the battery system temperature soar, thereby affecting the thermal performance of the battery. To showcase the efficacy of the proposed approach, four distinct case scenarios are studied, highlighting the critical importance of batteries within microgrid operations. A comparative analysis is conducted between linear and nonlinear models for TMS performance. A quantitative assessment based on simulation results demonstrates the precision of the linearized model, particularly in a multitemporal optimal power flow and day-ahead scheduling of microgrids incorporating energy storage units. Controlling the battery temperature within a permissible range (from 15 °C to 40 °C) is achieved by using a heating, ventilation, and air conditioning (HVAC) system. The paper explores the economic implications of energy storage units in microgrids by extracting and comparing daily operational costs with and without battery integration. The findings reveal that the inclusion of energy storage units yields substantial economic benefits, with potential profit margins of approximately 20 % during typical working days and 60 % on weekends.

Research on electro-hydraulic composite drive winch and energy recovery system for mobile crane

Owing to the high power consumption and limited control precision of traditional hydraulic drive winch systems, this study proposes hydraulic and electric-type energy recovery systems. The accumulator used in the hydraulic type has low energy density, which makes it difficult to store a large amount of energy. Meanwhile, the electric motor/generator used in the electric type cannot solve the secondary slip because of oil leakage, which leads to low controllability and high-power consumption under near-zero speed and high torque conditions. Thus, based on electric construction machinery with high-pressure, energy-dense electric energy storage units, this study proposes an electro-hydraulic composite drive winch and energy recovery system and control strategy for mobile cranes. Considering the good control characteristics of the electric motor/generator and the high-power density of the hydraulic accumulator, this hydroelectric composite drive and energy recovery system may solve the secondary sliding challenge and ensure large torque output at near-zero speed. A simulation model of the mobile crane is established to verify the feasibility of the proposed system and control strategy. The research results showed that the system is more efficient at recovering energy when the weight is lowered by a greater distance.

ВДОСКОНАЛЕННЯ МЕТОДИЧНОГО ТА ІНСТРУМЕНТАЛЬНОГО ЗАБЕЗПЕЧЕННЯ УПРАВЛІННЯ ПОПИТОМ В ЛІБЕРАЛІЗОВАНИХ РИНКАХ ЕЛЕКТРИЧНОЇ ЕНЕРГІЇ

Global decarbonisation and widespread use of alternative and renewable energy sources aims to shortage the fossil fuel using and reduce the harmful impact on the environment within the framework of the sustainable development paradigm. At the same time, wide integration into the power network of unmanaged generating units based on renewable energy sources in the absence of a sufficient number of electric energy storage units of the required capacity in conditions of unpredictability and instability of production may lead to the inability to provide reliable coverage of the consumers power load, which requires the use of alternative ways of balancing the power system. Under such conditions, the coordination of electric power (electricity) demand and supply for should be carried out exclusively by demand-side management in real time or near real time. That is why the improvement of methodological and instrumental provision of demand-side management tasks today is one of the most important components of the effectiveness of the "green" transition. To achieve the goal, the article analyzed the existing DSM-methods, performed an analysis of the requirements of national regulatory documents for DSM and service provision in the liberalized electricity market of Ukraine, described an improved ideal norm method and a modernized toolkit for demand-side management, as well as a reliable budgetary technical solution for the formation of information support for DSM in the retail electricity market is proposed, which together with dynamic pricing and the introduction of real-time tariffs will contribute to ensuring economic regimes of operation of the IPS and high-quality power supply to consumers. References 14, figures 4, tables 2.

Electric Vehicle Fast Charging: A Congestion-Dependent Stochastic Model Predictive Control under Uncertain Reference

This paper presents a control strategy aimed at efficiently operating a service area equipped with stations for plug-in electric vehicles’ fast charging, renewable energy sources, and an electric energy storage unit. The control requirements here considered are in line with the perspective of a service area operator, who aims at avoiding peaks in the power flow at the point of connection with the distribution grid, while providing the charging service in the minimum time. Key aspects of the work include the management of uncertainty in the charging power demand and generation, the design of congestion and state-dependent weights for the cost function, and the comparison of control performances in two different hardware configurations of the plant, namely BUS and UPS connection schemes. All of the above leads to the design of a stochastic model predictive controller aimed at tracking an uncertain power reference, under the effect of an uncertain disturbance affecting the output and the state of the plant in the BUS and UPS schemes respectively. Simulation results show the relevance of the proposed control strategy, according to an incremental validation plan focused on the tracking of selected references, the mitigation of congestion, the stability of storage operation over time, and the mitigation of the effect of uncertainty.

Adaptation and optimization of a photovoltaic system for a country house

This chapter provides the rationale for monitoring photovoltaic (photovoltaic) systems, its purpose, the need for proper measurement, and the frequency required to obtain meaningful results. The need for system monitoring falls into three groups: user feedback, performance review, and system evaluation. Each group is briefly summarized; other related topics include calibration, data storage, and data transfer. The text covers various monitoring modes such as performance testing, system evaluation, data collection and storage, as well as data analysis and reporting. The evaluation standards given by the International Electrotechnical Commission (IEC) are noted in the Data Analysis and Reporting section. The figures are provided to illustrate several types of displays that are an integral part of monitoring. Optimized modes of operation of the power part of a household photovoltaic system consisting of photovoltaic panels, an MRRT controller, an inverter and an electric energy storage unit, with Autonomous and network connection of the load. To build an optimal and cost-effective energy management strategy, it is necessary to take into account the energy profile of the resident, the characteristics of electricity production based on photovoltaic cells, and the electricity tariff for utilities. A photovoltaic system can be connected to the grid in order to receive energy from the grid or enter it into the network to eliminate the discrepancy between the generated, consumed and stored energy.

Chance-constrained optimization of distributed power and heat storage in integrated energy networks

Energy storage is widely recognized as an effective alternative to match the instantaneous imbalance between distributed renewable energy sources and loads. However, suitable installation sites and capacities are necessarily determined in integrated energy networks. This paper constructs a two-layer optimization model of integrated power and heat networks to obtain the optimal installation nodes and capacities of electric energy storage (EES) and thermal energy storage (TES) units. In the optimization model, the interchange of power to heat with storage units is collaborated to unitize distributed renewable energy sources and decrease comprehensive costs, including investment cost of storage units and operation cost. A chance-constrained optimization model is proposed to transform the uncertain variables of electric and heat loads into a deterministic optimization problem. The impacts of confidence levels involved in load probability distributions on the optimal nodes and capacities are analyzed. The results demonstrate that the optimal installation nodes are determined by the distributions of distributed power sources and load ratios in networks. The increased confidence level globally raises the optimal installation capacities of EES and TES. When the confidence level increases from 0.50 to 0.99, the utilization rate of wind power increases by 3.91 %, whereas the comprehensive cost increases by 22.34 %. The hybrid integrations of EES and TES consume more uncertain renewable power and improve the economic performances by the interchange of power to heat.

Stochastic multi-stage multi-objective expansion of renewable resources and electrical energy storage units in distribution systems considering crypto-currency miners and responsive loads

In order to mitigate the influence of global warming and greenhouse gasses emission, different proceedings are suggested such as utilizing renewable energies and demand response programs. This paper investigates the expansion of renewable resources and electrical energy storage units in distribution systems towards reducing investment costs and environmental pollution. Since the development of components is not possible in a single-stage due to the limitation of staff and funds, a multi-stage programming is applied to consider various restrictions. According to the penetration of crypto-currency miners in recent years, their impact is evaluated on the problem as the high-rate energy consumers. Moreover, the demand side management strategy and risk-averse scenario-based approach are implemented to analyze the role of responsive loads and model the renewable resources uncertainty, respectively. The results approve that simultaneous expansion of wind turbines, photovoltaics and electrical storage systems decreases the total pollution and cost by 100% and 99.98% after the third year, respectively. The simulations also validate that crypto-currency miners reduce the total revenue by 4.16%, whereas the responsive loads increase it by 9.89%. As well, the fluctuations of wind and solar power decrease the total revenue by 13.27%, in return, the robustness notably improves.

Optimal energy management of multi-carrier networked energy hubs considering efficient integration of demand response and electrical vehicles: A cooperative energy management framework

This paper presents a cooperative energy management approach for multi-carrier networked energy hubs. The proposed scheme facilitates energy hubs to exchange power for higher economic and environmental benefits. Based on the cooperative game theory, individual energy hubs cooperate to secure maximum profit, which is then fairly distributed among the hubs to ensure the economic stability of the coalition. The proposed model considers the networked system in which hubs are integrated with multi-energy resources such as electrical and natural gas supply, renewable sources, combined heat and power units (CHPs), gas boilers, electrical and thermal energy storage units to satisfy electrical and thermal demands. A scenario-based generation and reduction algorithm is employed to address the uncertain behaviour of sources. Moreover, a price-based demand response program (DR) and electrical vehicles (EVs) are integrated to make the network more flexible. To analyse the proposed cooperative energy management, the system is modelled as a mixed-integer linear programming problem. Results show that operating costs and greenhouse gas (GHG) emissions are reduced and the self-reliability of the networked system improves. With cooperation and flexible resources, the coalition achieves its maximum profit, which is fairly and stably distributed among the hubs by using Shapley value.

The study of the isolated power supply system operation with controlled distributed generation plants, energy storage units and drive load

THE PURPOSE. Investigation of the operating modes of an isolated power supply system with controlled distributed generation plants, energy storage units and a drive load. Determination of the influence of the proposed prognostic controller of a distributed generation plant on the control parameters and quality indicators of the control process under various operating modes of an isolated power supply system.METHODS. The studies were carried out on a computer model of an isolated power supply system of an industrial enterprise with a turbine generator plant, a wind generator plant and a high-power electric storage unit, for which a fuzzy control system and a prognostic controller were used. The simulation was performed in MATLAB using Simulink and SimPowerSystems packages.RESULTS. The article describes a computer model of an isolated power supply system, as well as a structural diagram of the proposed autoprognostic speed controller. The simulation results showed that the combined use of an energy storage unit and an auto-prognostic generator rotor speed controller makes it possible to ensure the stability and survivability of an isolated power supply system, increasing its damping properties. The use of a fuzzy control system of a wind-generating plant made it possible to ensure its stable operation in all considered modes.CONCLUSION. The auto-prognostic speed controller, which does not require special settings, and the energy storage unit provide high quality control indicators in normal and emergency modes. It is advisable to conduct further studies to coordinate the actions of the control system of the electric energy storage unit and the auto-prognostic speed controller of the distributed generation plant.

A Shrinking Horizon Model Predictive Controller for Daily Scheduling of Home Energy Management Systems

In this paper, the model predictive control (MPC) strategy is utilized in smart homes to handle the optimal operation of controllable electrical loads of residential end-users. In the proposed model, active consumers reduce their daily electricity bills by installing photovoltaic (PV) panels and battery electrical energy storage (BEES) units. The optimal control strategy will be determined by the home energy management system (HEMS), benefiting from the meteorological and electricity market data stream during the operation horizon. In this case, the optimal scheduling of home appliances is managed using the shrinking horizon MPC (SH-MPC) and the main objective is to minimize the electricity cost. To this end, the HEMS is augmented by the SH-MPC, while maintaining the desired operation time slots of controllable loads for each day. The HEMS is cast as a standard mixed-integer linear programming (MILP) model that is incorporated into the SH-MPC framework. The functionality of the proposed method is investigated under different scenarios applied to a benchmark system while both time-of-use (TOU) and real-time pricing (RTP) mechanisms have been adopted in this study. The problem is solved using six case studies. In this regard, the impact of the TOU tariff was assessed in Scenarios 1&#x2013;3 while Scenarios 4&#x2013;6 evaluate the problem with the RTP mechanism. By adopting the TOU tariff and without any load shifting program, the cost is <inline-formula> <tex-math notation="LaTeX">$\$ $ </tex-math></inline-formula>1.2274 while by using the load shifting program without the PV and BEES system, the cost would reduce to <inline-formula> <tex-math notation="LaTeX">$\$ $ </tex-math></inline-formula>0.8709. Furthermore, by using the SH-MPC model, PV system and the BEES system, the cost would reduce to <inline-formula> <tex-math notation="LaTeX">$\$ $ </tex-math></inline-formula>-0.282713 with the TOU tariff. This issue shows that the prosumer would be able to make a profit. By adopting the RTP tariff and without any load shifting program, the cost would be <inline-formula> <tex-math notation="LaTeX">$\$ $ </tex-math></inline-formula>1.22093 without any PV and BEES systems. By using the SH-MPC model, the cost would reduce to <inline-formula> <tex-math notation="LaTeX">$\$ $ </tex-math></inline-formula>1.08383. Besides, by adopting the SH-MPC, and the PV and BEES systems, the cost would reduce to <inline-formula> <tex-math notation="LaTeX">$\$ $ </tex-math></inline-formula>0.05251 with the RTP tariff, showing the significant role of load shifting programs, local power generation, and storage systems.

Selection of electricity storage devices for mobile DC traction substations

The aim of the study is to review the sources covering the problems of accumulating electricity on the railways and to find new solutions to reduce the use of electricity in traction power supply system. The article analyses some existing types of electric energy storage devices (capacitive, inertial, superconducting inductive, electrochemical, fuel cells and pumped storage power plants), their common installation locations, advantages, and disadvantages. The possibility of using them in railway traction power supply systems, in particular in mobile traction substations, is also assessed. In addition, the article lists the parameters on the basis of which the optimum type of storage device can be selected for the given conditions. The study concludes that the use of some types of energy storage devices in mobile traction substations is acceptable when regenerative braking can be used at the site, and this method of energy saving can be recommended in the engineering of new or reconstruction of existing traction substations. It has been found that capacitive and inertial (flywheel) electrical energy storage units are the most suitable in terms of parameters for installation of traction power supply systems.

Dynamic programming based economic day-ahead scheduling of integrated tri-generation energy system with hybrid energy storage

Solid oxide fuel cell (SOFC) is considered as a promising energy generation source in the future integrated energy system due to its high efficiency and flexibility in the combined cooling, heating and power (CCHP, tri-generation) system. However, optimization of the economic day-ahead scheduling is challenging due to various couplings between the energy storage components. To this end, an economic day-ahead scheduling model is proposed for the SOFC-based integrated tri-generation energy system (ITES), based on which dynamic programming (DP) is introduced for efficient solution. Considering the predicted cooling/heating/electric load profiles, the proposed dispatching optimization problem is constructed and solved by minimizing the fuel consumption subject to various device safety constraints. Simulation results based on a typical load scenario demonstrate the feasibility and efficiency of the proposed optimization method. It is revealed that the ITES with hybrid electrical and thermal energy storage units can not only achieve higher overall efficiency than the system with a single energy storage unit, but also significantly reduce the running time of the energy conversion devices. The proposed optimization framework in this paper can efficiently coordinate the operation among the energy generation, conversion and consumption components, depicting a promising prospect in the application of future ITES.

Empirical Analysis of High Voltage Battery Pack Cells for Electric Racing Vehicles

This paper examines the specifications of lithium battery cells, which are considered one of the most vital sources for electrical energy storage units. The specifications have been covered to associate battery performance with its usage for electrically powered motor vehicles. With the motivation of rapid deployment of electric vehicles (EVs) around the world, the key contribution of this study is to provide a comparative investigation of well-known commercially available Li-ion battery cells used as a pack for electric race car. Five lithium cells from different manufacturers were analyzed for start voltage, end voltage, current, and the use of active cooling under different test conditions. Thermal imaging was used to provide more comprehensive analysis of tested battery packs. The outcomes of this experimental investigation are described in the sections below in the order in which the analyses were conducted. The key findings of this study are presented in the conclusion section.

High-Performance Secure Access and Data Privacy Protection Method for 5G Border Routing Gateway

With the substantial increase in the amount of data information and the development of 5G technology, boundary computing technology based on 5G, as a real-time and efficient data processing method, has broad application prospects. The aggregation gateway further aggregates the power injection data of all electric energy storage units and sends it to the power company. The power company uses its own private key to access the aggregated data. Row decryption to obtain the total power data recovered in each time slot. The paper proposes a new solution using Lagrangian interpolation to ensure data privacy and security. The security shows that the algorithm can not only protect the privacy of the electric energy storage unit, but also realize the confidentiality and integrity of the injected data. Efficiency analysis shows that this algorithm can significantly reduce computational complexity and improve communication efficiency.

Methods Used to Extinguish Fires in Electric Vehicles

Aim: The aim of the article is to present the current state of knowledge regarding the possibility of suppressing or effectively extinguishing fires of electric vehicle. Due to the growing popularity of means of transport powered by electric batteries, the problem of emerging fires and their effects is becoming recognizable. Due to the possible violent process of combustion of lithium-ion batteries (hereinafter referred to as Li-Ion batteries), a fire in a vehicle may lead to a wide range of property damage. For at least a decade, intensive efforts have been made to develop appropriate methods to allow firefighters to deal with the problem of fires of electric vehicles. These activities were directed, among others, at new fire extinguishing/suppression techniques, innovative extinguishing agents and methods of their application. Introduction: Taking into account the current global trends in changing the method of powering vehicles from fossil fuels into electricity, the occurrence of such events should be expected to intensify. The authors systematize the issue by analysing the literature on fires, Li-Ion batteries being a critical ele- ment that may initiate a fire. The adopted and practiced methods of extinguishing/suppressing a fire as well as the used extinguishing agents were also analysed. The publication may be an element helpful in selecting the most optimal fire extinguishing method of the electric energy storage unit in a vehicle. Methodology: The review of the current state of knowledge was made based on publications on the fire characteristics of Li-Ion batteries, as well as works and research projects in the field of extinguishing methods and the effectiveness of various extinguishing agents. In addition, the procedures used by the emergency services and selected real events were analysed. Conclusions: Fires of Li-Ion batteries are a relatively new and growing phenomenon. Fires in fully or partially electric vehicles are much more difficult to fully extinguish compared to fires in vehicles with internal combustion engines. So far, no effective method has been developed that would allow a fire to be extinguished in a short time. Activities in this area focus on minimizing the effects. There is still a need to look for new technical and tactical solutions in order to optimize the procedures leading to more effective activities of the services in this type of incidents. Keywords: lithium-ion battery, Li-Ion, fire, extinguishing, suppression Type of article: review article

Analysis of Electric Vehicles Motion Modes Influence on Traction Batteries Aging Based on WLTC

The paper considers the growth rates of electric vehicles, taking into account the development of electrochemical energy storage. The main lithium batteries aging mechanisms under conditions of uneven load and reversible nature of energy exchange processes with short modes of recharging batteries during regenerative braking are determined. To assess the aging of the lithium battery, the WLTC driving cycle was taken as a basis, in accordance with which the load on the electric vehicle energy storage unit the was formed. A Nissan Leaf equipped with energy storage units (ESU) of different energy intensity was adopted as a test sample. Current diagrams were obtained for one battery cell, minimum, average and maximum currents, as well as durations of traction, braking and stopping modes in various control modes of electric rolling stock are given. An assumption is made about the growth of the energy intensity of the ESU in the future period and its influence on the load of the storage battery is determined. On the basis of the data processing carried out, the main changes in the processes occurring in the power source, associated with an increase in the energy intensity of the ESU, have been revealed

Повышение энергоэффективности электропоезда за счет установки накопителей электрической энергии

Objective: To increase the energy effi ciency of the Russian multi-unit rolling stock of railways by installing electric energy storage devices. Methods: The goal is achieved by applying integrated approach method to the problem of multi-unit rolling stock energy efficiency, with focus on the practical signifi cance and economic feasibility of the results. Results: The solutions produced can serve as a basic concept for the modernization of domestic rolling stock. Practical importance: Concepts of an electric train with electric energy storage units based on Russian electric trains have been developed in order to increase their energy efficiency.

The Value and Optimal Sizes of Energy Storage Units in Solar-Assist Cogeneration Energy Hubs

Cogeneration is becoming increasingly popular in building and community energy systems with demands on electricity and heat, which is suitable for residential and industrial use in remote areas. This paper considers a stand-alone cogeneration energy hub. The electrical and thermal energies are produced by a combined heat and power (CHP) unit, photovoltaic panels, and a solar thermal collector. Since solar units generate no electricity and heat during the night, energy storage units which shift demands over time can promote the usage of solar energy and reduce the fuel cost of the CHP unit. This paper proposes a method to retrieve the optimal operation cost as an explicit function in the capacity parameters of electric and thermal energy storage units, reflecting the value of energy storage in the cogeneration energy hub. The capacity parameter set is divided into a collection of polyhedrons; on each polyhedron, the optimal value is an affine function in the capacity parameters. Furthermore, the optimal sizes of system components are discussed. The capacity of the CHP unit is determined from a linear program, ensuring supply adequacy; the capacities of solar generation and energy storage units are calculated based on the cost reduction and the budget. Case studies demonstrate the effectiveness of the proposed method.