Battery energy storage system with a fixed connection lacks the ability to meet various power and energy demands of the power grid. In this thread, Flexible Battery Energy Storage Systems (FBESS) ...with a highly controllable structure is proposed as a new path for future energy storage. With the increasing complexity of the battery system, an advanced strategy is needed from the control side to tune the multi-terminal of the FBESS. Especially, the FBESS, with a large number of switches, increases the dimension of the decision space, while the traditional control method can not well handle such a task. In addition, the control of the FBESS should consider both the working performance and the balance requirement of the cells. Thus, a Proximal Policy Optimization (PPO) based framework is proposed in this article to dynamically learn an optimal control strategy for FBESS. Utilizing the clipped surrogate objective, PPO can stably update the policy online through gradient descent. By utilizing its easy implementable property, the proposed method can efficiently control the high dimensional action space and synchronously improve the working time and the balancing performance. Experimental results with data collected from a real battery system prove the validation of the proposed framework.
•Rigorous review on BESS sizing, constraint and optimization models are discussed.•BESS optimization objectives and methods have classified in various applications.•Explores the shortages of existing ...optimal BESS to identify gaps for future research.•Issues and challenges are highlighted to provide a future direction to the researchers.•Conveys significant recommendations to the researchers and policymakers.
Due to urbanization and the rapid growth of population, carbon emission is increasing, which leads to climate change and global warming. With an increased level of fossil fuel burning and scarcity of fossil fuel, the power industry is moving to alternative energy resources such as photovoltaic power (PV), wind power (WP), and battery energy-storage systems (BESS), among others. BESS has some advantages over conventional energy sources, which include fast and steady response, adaptability, controllability, environmental friendliness, and geographical independence, and it is considered as a potential solution to the global warming problem. This paper provides a comprehensive review of the battery energy-storage system concerning optimal sizing objectives, the system constraint, various optimization models, and approaches along with their advantages and weakness. Furthermore, for better understanding, the optimization objectives and methods have been classified into different categories. This paper also provides a detailed discussion on the BESS applications and explores the shortages of existing optimal BESS sizing algorithms to identify the gaps for future research. The issues and challenges are also highlighted to provide a clear idea to the researchers in the field of BESS. Overall, this paper conveys some significant recommendations that would be useful to the researchers and policymakers to structure a productive, powerful, efficient, and robust battery energy-storage system toward a future with a sustainable environment.
•The dynamic thermal rating (DTR) system, battery storage system (BSS) and network topology optimization (NTO) technique are deployed to reduce network congestions, operational costs and wind ...curtailment.•The long-term, multi-area weather conditions of the DTR system are considered for more accurate and practical studies.•The BSS energy capacity and power rating for maintaining the prevailing security of supply of a large wind-integrated network are probabilistically determined.
The nonflexible operations of transmission networks with high load demand and wind power increase the likelihood of power congestions and deteriorate grid reliability. This condition causes higher load curtailments and inhibits the penetrations of wind power, subsequently leading to higher dispatch cost because more expensive generators compensate for the loss of wind integrations. These unfavourable factors contribute to a higher total system operating cost, which should be reduced. This paper applies a network topology optimisation technique to optimise line and busbar switching for relieving network congestions and improving network flexibility. A dynamic thermal rating system is used to enhance overhead line ratings. A battery storage system is utilised to time shift wind power usage and avoid wind spillage. These methods are effective but they have been studied only in isolation. This paper presents an assessment framework that combines all the three methods in a single model to evaluate their synergistic effects on wind integration and network reliability. The proposed framework is generic and can be applied on any networks with changes only to the numerical results. The battery energy and power ratings required to maintain the prevailing security of supply standards in a large scale wind-integrated network are determined probabilistically. Case studies performed on a modified IEEE 24-bus reliability test system show that the proposed combination of methods reduces system dispatch, load curtailment and wind curtailment costs the most when compared to any combinations with fewer methods or using each method in isolation.
DC-series integration introduces a novel approach to seamlessly integrate a solar photovoltaic (PV) array and a battery energy storage (BES) in series. This system, referred to as the PV-integrated ...battery energy storage system-dc series (PVBESS-DCS), simplifies integration and enhances power density by leveraging the inherent voltage-source characteristics of batteries and adopting the concept of partial power processing. However, addressing voltage variations of a PV array and a BES under different operational conditions remains a challenge to apply the PVBESS-DCS to a regulated dc system, where the dc-bus voltage is fixed. This article proposes a PVBESS-DCS solution tailored for regulated dc systems. Within this framework, we present a controllable series voltage source compensating for the voltage differences between the PV and BES sources and the dc bus. Thus, the system can perform PV maximum power point tracking and curtailment control while charging and discharging BES and connected to a regulated dc bus. Additionally, we present a single-stage multiport partial power processing dc-dc converter designed for the proposed PVBESS-DCS. It utilizes a triple active bridge dc-dc converter topology. This article presents operating principles, control strategies, simulation results, and experimental findings of the proposed PVBESS-DCS for regulated dc systems.
Efficient operation of battery energy storage systems requires that battery temperature remains within a specific range. Current techno-economic models neglect the parasitic loads heating and cooling ...operations have on these devices, assuming they operate at constant temperature. In this work, these effects are investigated considering the optimal sizing of battery energy storage systems when deployed in cold environments. Here, a peak shaving application is presented as a linear programming problem which is then formulated in the PYOMO optimization programming language. The building energy simulation software EnergyPlus is used to model the heating, ventilation, and air conditioning load of the battery energy storage system enclosure. Case studies are conducted for eight locations in the United States considering a nickel manganese cobalt oxide lithium ion battery type and whether the power conversion system is inside or outside the enclosure. The results show an increase of 42% to 300% in energy capacity size, 43% to 217% in power rating, and 43% to 296% increase in capital cost dependent on location. This analysis shows that the heating, ventilation, and air conditioning load can have a large impact on the optimal sizes and cost of a battery energy storage system and merit consideration in techno-economic studies.
•Proposing an environmental/economic model for optimal energy management.•Considering renewable energy resources in the presence of Photovoltaic and battery•Presenting modified bat algorithm (MBA) ...algorithm for optimizing Micro-grid•Reporting superior solutions in Short-Term Scheduling and Micro-grid Energy Management
This paper suggests a new energy management system for a grid-connected microgrid with various renewable energy resources including a photovoltaic (PV), wind turbine (WT), fuel cell (FC), micro turbine (MT) and battery energy storage system (BESS). For the PV system operating in the microgrid, an innovative mathematical modelling is presented. In this model, the effect of various irradiances in different days and seasons on day-ahead scheduling of the microgrid is evaluated. Moreover, the uncertainties in the output power of the PV system and WT, load demand forecasting error and grid bid changes for the optimal energy management of microgrid are modelled via a scenario-based technique. To cope with the optimal energy management of the grid-connected microgrid with a high degree of uncertainties, a modified bat algorithm (MBA) is employed. The proposed algorithm leads to a faster computation of the best location and more accurate result in comparison with the genetic algorithm (GA) and particle swarm optimization (PSO) algorithm. The simulation results demonstrate that the use of practical PV model in a real environment improve the accuracy of the energy management system and decreases the total operational cost of the grid-connected microgrid.
Battery energy storage systems (BESS) are forecasted to play a vital role in the future grid system, which is complex but incredibly important for energy supply in the modern era. Currently, Li-ion ...batteries are the most widely deployed BESS for a wide range of grid services but need substantial understanding and improvement for effective market creation. Hence, the main purpose of this review is to provide a comprehensive overview of the current status and challenges of Li-ion battery energy storage systems for grid application from various aspects based on real-world projects.
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•Battery energy storage accounts for only 1% of total energy storage used today.•Li-ion batteries account for 78% of BESS in operation.•The major applications of Li-ion BESS are frequency regulation and peak shaving.•The major degradation mechanism of Li-ion batteries is due to SEI layer growth.•Code and Standard development for ESS takes 3–6 years.
Renewable energy, such as hydro power, photovoltaics and wind turbines, has become the most widely applied solutions for addressing issues associated with oil depletion, increasing energy demand and ...anthropogenic global warming. Solar and wind energy are strongly dependent on weather resources with intermittent and fluctuating features. To filter these variabilities, battery energy storage systems have been broadly accepted as one of the potential solutions, with advantages such as fast response capability, sustained power delivery, and geographical independence. During the implementation of battery energy storage systems, one of the most crucial issues is to optimally determine the size of the battery for balancing the trade-off between the technical improvements brought by the battery and the additional overall cost. Numerous studies have been performed to optimise battery sizing for different renewable energy systems using a range of criteria and methods. This paper provides a comprehensive review of battery sizing criteria, methods and its applications in various renewable energy systems. The applications for storage systems have been categorised based on the specific renewable energy system that the battery storage will be a part. This is in contrast to previous studies where the battery sizing approaches were either arranged as an optimised component in renewable systems or only accounted for one category of renewable system. By taking this approach, it becomes clear that the critical metrics for battery sizing, and by extension the most suitable method for determining battery size, are determined by the type of renewable energy system application, as well as its size. This has important implications for the design process as the renewable energy system application will drive the battery energy storage system sizing methodology chosen.
The modular multilevel converter-based battery energy storage system (MMC-BESS) can help the power grid to run safely and stably, which plays an important role in the modern power grid. The ...inconsistency of cells in BESS may lead to overcharge or overdischarge of cells, which may decrease the operation life of battery packs and cause safety problems. Normally, before the MMC-BESS is connected to the grid, it is necessary to prebalance the system batteries in an offline state. This article analyzes the topology, the mathematical model, and the equalization control model in offline MMC-BESS. According to the analysis, an offline MMC-BESS stepwise balancing control strategy considering the state of charge, state of health, and state of function, is proposed. In this strategy, the state of dischargeable energy is set as the criterion of offline equalization of the system. The balancing of submodules in MMC-BESS would be achieved by controlling the circulating currents and voltages of arms. Finally, the feasibility of the offline equalization control strategy is verified by simulation and experiment.
•Integrated planning of Internet data centers and battery energy storage systems.•Coupled cyber-physical modelling of Internet data centers and a smart grid.•Multi-objective modelling of the planning ...task.
Modern power grids have been becoming complex cyber-physical systems integrated with distributed energy sources and information and communication facilities. With prevalence of cloud computing, geo-distributed, networked data centers have become an integrated part of modern grids. The coupling impact between data centers and smart grids thus becomes an important consideration. This paper proposes an integrated planning scheme that optimally determines the locations and capacities of interconnected Internet data centers and battery energy storage systems in a smart grid. The model is formulated as a multi-objective optimization problem, in which both computational performance metrics of Internet data centers and operational criteria of the grid are coordinately considered as three inter-related but conflict objectives; the coupling impact between the cyber and energy resources are modelled. An advanced evolutionary algorithm – Multi-Objective Natural Aggregation Algorithm is used to solve the model. Extensive case studies are conducted to demonstrate the reasonability and effectiveness of the proposed integrated planning method.
