Hydrogen energy plays a crucial role in integrating renewable, reducing carbon emissions, and boosting the operational flexibility of multi-energy microgrids (MEMG), owing to its substantial storage capacity and clean characteristics. However, a key challenge arises in the coordinated dynamic dispatch between power flows and the multi-stage hydrogen value chain, which includes production, conversion, utilization, and waste heat recovery. To address this, we introduce a novel multi-time scale operational framework for MEMG that considers electricity-hydrogen coupling and encompass the entire hydrogen process chain. This framework operates on a three-phase model: day-ahead scheduling aimed at minimizing daily operating costs; intraday rolling optimization every 15 min to adjust for renewable energy fluctuations; and real-time adjustments to fine-tune key conversion devices. Additionally, a carbon emission flow is integrated into the day-ahead phase to guide the dispatch of hydrogen and electricity towards low-carbon operations. Case studies demonstrate that our proposed framework lowers total operating costs by 6.64% and cuts carbon emissions by 13.06% compared to traditional day-ahead scheduling. This work offers a practical, system-level operational strategy to enhance both the economic and environmental performance of future flexible energy systems.
Production of electric energy or power. Powerplants. Central stations
Pure phase change materials (PCMs) have drawbacks such as low thermal conductivity and poor physical properties like flammability, which limit their further application in battery thermal management systems. This paper introduces an innovative flame-retardant composite phase change material (CPCM) made from paraffin, expanded graphite, chitosan (CS), ammonium polyphosphate (APP), and aluminum hypophosphite (AHP). The physicochemical properties and flame-retardant performance of CPCMs with five different flame-retardant ratios of 9%, 12%, 15%, 18%, and 21% are studied, and their application effects in battery thermal safety are revealed. The results show that the combination of flame retardants CS, APP, and AHP exhibits effective synergistic effects, and the prepared CPCM exhibits good flame-retardant properties and thermal management effects. The CPCM exhibits outstanding thermal management performance when the flame-retardant content is 12%. At a maximum discharge rate of 3C, compared to natural air-cooling conditions, the maximum battery temperature and temperature difference are controlled within the safe range of 41 °C and below 5 °C, respectively. The CPCM can play an important role in the thermal safety of lithium-ion batteries.
Production of electric energy or power. Powerplants. Central stations, Industrial electrochemistry
Determining charge and discharge behavior is essential for optimizing charging strategies and evaluating balancing algorithms in battery energy storage systems and electric vehicles. Conventionally, a sequence of circuit simulations or tedious hardware tests is required to evaluate the performance of the balancing algorithm. To mitigate these problems, this paper proposes a variable capacitor model that can be easily built from the incremental capacity curve. This model provides a direct and insightful R-C time constant method for the charge/discharge time calculation. After validating the model accuracy by experimental results based on the cylindrical lithium-ion cell test, a switched-capacitor active balancing and a passive cell balancing circuit are implemented to further verify the effectiveness of the proposed model in calculating the cell balancing time within 2% error.
Production of electric energy or power. Powerplants. Central stations, Industrial electrochemistry
Abstract Constant power loads (CPLs) introduce negative impedance in direct current microgrids (DCMGs), which is a major challenge. This negative impedance can significantly reduce the overall damping of the system, making it less stable and harder to control. To address this issue, output virtual resistance (VR) shaping is commonly employed to enhance system damping and improve power‐sharing amongst distributed generators (DGs). The technique proposed in this work involves an adaptive variation of the DG virtual output resistance (RV) linearly with the output current. This shows improved power sharing between sources. The work compares the small signal stability criteria and the minor loop gain methods for linear, non‐linear, and inverse droop controllers to determine the controller parameters with constant power loads. The control scheme is extensively tested through simulations for four different droop control schemes. The work also validates the DCMG performance when the DERs work with different droop controllers (heterogenous of controllers) to assess constant power load penetration, performance in meshed configurations, and DG plug‐and‐play operations. Additionally, improved power sharing performance was validated through a controller hardware in the loop (CHIL) based implementation.
Energy industries. Energy policy. Fuel trade, Production of electric energy or power. Powerplants. Central stations
Federated Learning (FL) is a decentralized training framework widely used in IoT ecosystems that preserves privacy by keeping raw data local, making it ideal for IoT-enabled cyber-physical systems with sensing and communication like Smart Grids (SGs), Connected and Automated Vehicles (CAV), and Electric Vehicle Charging Stations (EVCS). With the rapid expansion of electric vehicle infrastructure, securing these IoT-based charging stations against cyber threats has become critical. Centralized Intrusion Detection Systems (IDS) raise privacy concerns due to sensitive network and user data, making FL a promising alternative. However, current FL-based IDS evaluations overlook practical challenges such as system heterogeneity and non-IID data. To address these challenges, we conducted experiments to evaluate the performance of federated learning for anomaly detection in EV charging stations under system and data heterogeneity. We used FedAvg and FedAvgM, widely studied optimization approaches, to analyze their effectiveness in anomaly detection. Under IID settings, FedAvg achieves superior performance to centralized models using the same neural network. However, performance degrades with non-IID data and system heterogeneity. FedAvgM consistently outperforms FedAvg in heterogeneous settings, showing better convergence and higher anomaly detection accuracy. Our results demonstrate that FL can handle heterogeneity in IoT-based EVCS without significant performance loss, with FedAvgM as a promising solution for robust, privacy-preserving EVCS security.
Katherine A Acord, Alexander D Dupuy, Qian Nataly Chen
et al.
Additive manufacturing of solid-state batteries is advantageous for improving the power density by increasing the geometric complexity of battery components, such as electrodes and electrolytes. In the present study, bulk three-dimensional Li _1+ _x Al _x Ti _2− _x (PO _4 ) _3 (LATP) electrolyte samples were prepared using the laser powder bed fusion (L-PBF) additive manufacturing method. Li _3 PO _4 (LPO) was added to LATP to compensate for lithium vaporization during processing. Chemical compositions included 0, 1, 3, and 5 wt. % LPO. Resulting ionic conductivity values ranged from 1.4 × 10 ^−6 –6.4 × 10 ^−8 S cm ^−1 , with the highest value for the sample with a chemical composition of 3 wt. % LPO. Microstructural features were carefully measured for each chemical composition and correlated with each other and with ionic conductivity. These features and their corresponding ranges include: porosity (ranging from 5% to 19%), crack density (0.09–0.15 mm mm ^−2 ), concentration of residual LPO (0%–16%), and concentration and Feret diameter of secondary phases, AlPO4 (11%–18%, 0.40–0.61 µ m) and TiO2 (9%–11%, 0.50–0.78). Correlations between the microstructural features and ionic conductivity ranged from −0.88 to 0.99. The strongest negative correlation was between crack density and ionic conductivity (−0.88), confirming the important role that processing defects play in limiting the performance of bulk solid-state electrolytes. The strongest positive correlation was between the concentration of AlPO4 and ionic conductivity (0.99), which is attributed to AlPO4 acting as a sintering aid and the role it plays in reducing the crack density. Our results indicate that additions of LPO can be used to balance competing microstructural features to design bulk three-dimensional LATP samples with improved ionic conductivity. As such, refinement of the chemical composition offers a promising approach to improving the processability and performance of functional ceramics prepared using binderless, laser-based additive manufacturing for solid-state battery applications.
Production of electric energy or power. Powerplants. Central stations, Renewable energy sources
Testing the operation of protection devices against parallel arc breakdown and spark gaps in the event of a ground faultTHE PURPOSE. Develop a laboratory rig for testing parallel arc fault and spark gap protection devices for tripping in the event of a ground fault. Conduct laboratory rig tests with subsequent development of requirements for the use of parallel arc fault and spark gap protection devices for tripping in the event of a ground fault.METHODS. Mathematical and statistical methods of analysis were used to achieve the stated objective. Laboratory tests of parallel arc fault and spark gap protection devices for different network parameters for correct tripping in the event of a ground fault.RESULTS. Laboratory tests of parallel arc fault and spark gap protection devices for correct tripping in the event of a ground fault were conducted with different network parameters. The oscilloscope recorded the shape of the voltage and current curve in the event of a ground fault and the tripping time of the devices. The tested devices demonstrated the ability to recognize and disconnect a ground fault. The tripping time of the devices varies, however, does not exceed the established requirements.CONCLUSION. A laboratory stand has been developed for testing parallel arc breakdown and spark gap protection devices for operation during a ground fault. This stand makes it possible to test devices for adequate operation during a ground fault with subsequent certification. The tests conducted demonstrate the need to develop mandatory requirements for the device to standardize their operating algorithm. Therefore, the use of this protection device can contribute to safer operation of low-voltage electrical networks by preventing emergency situations and reducing the risk of fires. This is an important technical aspect for improving the reliability and safety of power supply.
Production of electric energy or power. Powerplants. Central stations
Balance functions have been used extensively to elucidate the time evolution of quark production in heavy-ion collisions. Early models predicted two stages of quark production, one for light quarks and one for the heavier strange quark, separated by a period of isentropic expansion. This led to the notion of clocking particle production and tracking radial flow effects, which drive the expansion of the system. In this talk, balance functions of identified particles in different multiplicity classes of pp collisions at $\sqrt{s} = 13.6\;\text{TeV}$ recorded by ALICE during the LHC Run 3 are reported. The results are compared with different models as well as with previously published results on pp and Pb--Pb collisions at different energies. The results enable tracking the balancing of electric charge and strangeness by measuring how the widths and integrals of the charge and strangeness balance functions evolve across different collision energies.
Dockless electric micro-mobility services (e.g., shared e-scooters and e-bikes) have been increasingly popular in the recent decade, and a variety of charging technologies have emerged for these services. The use of charging stations, to/from which service vehicles are transported by the riders for charging, poses as a promising approach because it reduces the need for dedicated staff or contractors. However, unique challenges also arise, such as how to incentivize riders to drop off vehicles at stations and how to efficiently utilize the vehicles being charged at the stations. This paper focuses on dockless e-scooters as an example and develops a new spatial queuing network model to capture the steady-state scooter service cycles, battery consumption and charging processes, and the associated pricing and management mechanisms. Building upon this model, a system of closed-form equations is formulated and incorporated into a constrained nonlinear program to optimize the deployment of the service fleet, the design of charging stations (i.e., number, location, and capacity), user-based charging price promotions and priorities, and repositioning truck operations (i.e., headway and truck load). The proposed queuing network model is found to match very well with agent-based simulations. It is applied to a series of numerical experiments to draw insights into the optimal designs and the system performance. The numerical results reveal strong advantages of using charging stations for shared dockless electric micro-mobility services as compared to state-of-the-art alternatives. The proposed model can also be used to analyze other micromobility services and other charging approaches.
Luca Ambrosino, Giuseppe Calafiore, Khai Manh Nguyen
et al.
As the global focus on combating environmental pollution intensifies, the transition to sustainable energy sources, particularly in the form of electric vehicles (EVs), has become paramount. This paper addresses the pressing need for Smart Charging for EVs by developing a comprehensive mathematical model aimed at optimizing charging station management. The model aims to efficiently allocate the power from charging sockets to EVs, prioritizing cost minimization and avoiding energy waste. Computational simulations demonstrate the efficacy of the mathematical optimization model, which can unleash its full potential when the number of EVs at the charging station is high.
Abstract Bifunctional hybrid anodes (BHAs), which are both a high‐performance active host material for lithium‐ion storage as well as a guiding agent for homogeneous lithium metal nucleation and growth, exhibit significant potential as anodes for next‐generation high‐energy‐density lithium‐ion batteries (LIBs). In this study, sulfur‐doped hard carbon nanosphere assemblies (S‐HCNAs) were prepared through a hydrothermal treatment of a liquid organic precursor, followed by high‐temperature thermal annealing with elemental sulfur for application as BHAs for LIBs. In a carbonate‐based electrolyte containing fluoroethylene carbonate additive, the S‐HCNAs showed high lithium‐ion storage capacities in sloping as well as plateau voltage sections, good rate capabilities, and stable cyclabilities. In addition, high average Coulombic efficiencies (CEs) of ~96.9% were achieved for dual lithium‐ion and lithium metal storage cycles. In the LIB full‐cell tests with typical NCM811 cathodes, the S‐HCNA‐based BHAs containing ~400 mA h g−1 of excess lithium led to high energy and power densities of ~500 W h kg−1 and ~1695 W kg−1, respectively, and a stable cycling performance with ~100% CEs was achieved.
Production of electric energy or power. Powerplants. Central stations
As the main body of resource aggregation, virtual power plant (VPP) not only needs to participate in the external energy market, but also needs to optimize the management of internal resources.Different from other energy storage systems, hydrogen energy storage systems can participate in the hydrogen market in addition to the backup and supplement functions of electric energy.For a virtual power plant operator (VPPO), it is necessary to optimize the dispatch of internal resources as well as to develop a bidding strategy for both the electricity and hydrogen markets based on operational conditions and external market information.In this study, a two-stage model was developed, taking into account the interaction mechanism between the internal and external sides.The first stage of the model was based on the operational optimization of the internal resources of renewable energy, flexible load, pumped storage and hydrogen storage systems, while the second stage of the model aimed to optimize the bidding strategy by maximizing the total revenue in the electricity energy market, auxiliary services market and hydrogen market.
Applications of electric power, Production of electric energy or power. Powerplants. Central stations
Multi-infeed AC-DC hybrid system is the notable form of China’s power grid upgraded because of the distribution of the generation and load. Multiple high-capacity high voltage direct current transmission lines enhance the transmission capacity, while the problem of small signal stability will emerge new features. As the complexity of the power grid increases, the small signal stability problem faced by multi-feed AC-DC power systems becomes more severe, and a specific theoretical analysis is urgently needed. The article introduced the typical structures and characteristics of multi-feed AC-DC hybrid systems. The system dynamic interaction mechanisms and the stability problems under the small signal stability caused by AC-DC system interaction were reviewed. The research methods and their achievements in this field were summarized. The future developing trend of multi-feed AC-DC hybrid system and the challenges were discussed to provide references for related research work at last.
Applications of electric power, Production of electric energy or power. Powerplants. Central stations