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As one of the representative models in the field of image generation, generative adversarial networks (GANs) face a significant challenge: how to make the best trade-off between the quality of generated images and training stability. The U-Net based GAN (U-Net GAN), a recently developed approach, can generate high-quality synthetic images by using a U-Net architecture for the discriminator. However, this model may suffer from severe mode collapse. In this study, a stable U-Net GAN (SUGAN) is proposed to mainly solve this problem. First, a gradient normalization module is introduced to the discriminator of U-Net GAN. This module effectively reduces gradient magnitudes, thereby greatly alleviating the problems of gradient instability and overfitting. As a result, the training stability of the GAN model is improved. Additionally, in order to solve the problem of blurred edges of the generated images, a modified residual network is used in the generator. This modification enhances its ability to capture image details, leading to higher-definition generated images. Extensive experiments conducted on several datasets show that the proposed SUGAN significantly improves over the Inception Score (IS) and Fréchet Inception Distance (FID) metrics compared with several state-of-the-art and classic GANs. The training process of our SUGAN is stable, and the quality and diversity of the generated samples are higher. This clearly demonstrates the effectiveness of our approach for image generation tasks. The source code and trained model of our SUGAN have been publicly released. [ABSTRACT FROM AUTHOR]

Polyvinylidene fluoride (PVDF) porous membranes were prepared by a two-step method of surface gelation-immersion precipitation phase inversion. The effects of spraying CS solution concentrations on the structure and properties of membranes were investigated. The results showed that with the concentration increasing of CS solution spraying on the surface of the casting solution film, the porosity of PVDF membranes gradually increased, the mean pore diameter of membranes firstly increased and then reduced, the surface contact angle decreased, and β crystal content in the top surface of membranes gradually decreased. The top surface of membrane without spraying CS solution displayed a dense structure, while the top surface of membranes after spraying CS solution exhibited a porous structure, while the cross-sectional structure of all membranes was composed of the finger-like voids. When the concentrations of spraying CS solution increased, the water flux of membranes firstly increased and then decreased. [ABSTRACT FROM AUTHOR]

The sufficient and reversible active lithium is the cornerstone for the operation of high‐energy lithium‐ion batteries. However, active lithium is inevitably depleted due to the formation of a solid electrolyte and the presence of irreversible side reactions. The shortage of lithium in optimally designed batteries not only leads to a depreciation of energy density but also deteriorates the electrode structure resulting in degradation of cycle life. Inspiringly, prelithiation technology that additionally compensates for lithium has been proposed and is playing an increasingly significant role in enhancing battery energy density and prolonging cycle life. Herein, guided by the factors that initiate lithium loss, the action mechanism and the effectiveness of prelithiation are scrutinized. Moreover, the emerging advanced prelithiation technologies based on anode/cathode materials, the key barriers, and the applicability at scale are systematically summarized and compared. Integrating the challenges and development trends aspires to provide a comprehensive prelithiated hybrid lithium replenishment and storage technology as a reference in the scale‐up of prelithiation technologies. [ABSTRACT FROM AUTHOR]

The use of starch as renewable resource to produce eco-friendly hybrid latex has received an increasing attention in industrial application. In this work, enzymatically hydrolyzed starch-graft-poly( n -butyl acrylate- co -methyl methacrylate) (ES-g-P(BA-MMA)) latexes were synthesized by seeded surfactant-free emulsion polymerization. A complex initiation system was used to enhance the grafting efficiency. The mechanisms of initiation and graft copolymerization were discussed. The ES-g-P(BA-MMA) latexes were characterized by Fourier transform infrared spectroscopy, dynamic light scattering, transmission electronic microscopy (TEM), and differential scanning calorimetry. The effect of reaction condition on graft copolymerization was investigated. The evolution of particle morphology was revealed by the TEM. The ES-g-P(BA-MMA) latexes were used as binders for paper coating. The strength-related properties of coated paper were evaluated. The results showed that the folding resistance and picking resistance were improved. All the other properties were at least equally good as in the reference sample. The crosslinked ES-g-P(BA-MMA) latex was more effective in improving properties. The folding resistance and wet tensile strength index were enhanced significantly by 29.5% and 36.6%, respectively. This study provides an alternative choice for paper coating to develop coated paper with better properties. [ABSTRACT FROM AUTHOR]

The effects of the crystal phases of ZrO 2 in the Pt–WO x /ZrO 2 catalysts on glycerol hydrogenolysis to 1,3-propanediol (1,3-PDO) were comparatively studied. Pt and WO x were sequentially deposited on monoclinic ( m -ZrO 2 ) and tetragonal ( t -ZrO 2 ) ZrO 2 supports with similar surface areas by the wetness impregnation method. On both catalysts, sub-nanosized Pt particles were well dispersed on the supports, and the WO x species were mainly in the monomeric state and partly covered the Pt particles. The Pt–WO x / m -ZrO 2 catalyst had larger Pt particle size and less Brønsted acid sites than the Pt–WO x / t -ZrO 2 catalyst. In glycerol hydrogenolysis, the glycerol conversion and 1,3-PDO selectivity on the Pt–WO x / m -ZrO 2 catalyst were less than one half of those on the Pt–WO x / t -ZrO 2 catalyst. The Pt–WO x / t -ZrO 2 catalyst exhibited a high 1,3-PDO yield of 49.4%, an excellent 1,3-PDO productivity of 5.10 g g Pt −1 h −1 , and good recyclability. The superiority of the Pt–WO x / t -ZrO 2 catalyst in glycerol hydrogenolysis to 1,3-PDO is attributed to the better synergy between smaller Pt particles in affording hydrogen atoms and more Brønsted acid sites in converting glycerol to the intermediate suitable for the formation of 1,3-PDO. [ABSTRACT FROM AUTHOR]

Monodisperse particles with eccentric core-shell structure were prepared via surfactant-free emulsion polymerization (SFEP) using enzymatically hydrolyzed starch (EHS) as stabilizers. A possible mechanism of the particle formation was proposed. The EHS and graft copolymer were characterized by FTIR, size exclusion chromatography, TEM, dynamic laser scattering, DSC, and thermogravimetric analysis. The particle size increased from 148 to 452 nm with the decrease in concentration and molecular weight of EHS. Application of the EHS as the stabilizer for SFEP showed that the EHS effectively stabilized latex particles and produced monodisperse latexes. The TEM and DSC results indicated that the eccentric core-shell particles were obtained and the compatibility of two phases was improved. The EHS content of the copolymer was approximately 15%, determined by the TGA results. This work provided an efficient, cheap, and eco-friendly method to produce monodisperse particles decorated by starch oligo- or polysaccharides. [ABSTRACT FROM AUTHOR]

It has been documented that W-modified Pt catalysts with relatively high tungsten contents are effective for the catalytic transformation of biodiesel-derived glycerol to 1,3-propanediol (1,3-PDO). Herein, we report a new finding that Pt/W–SBA-15 catalysts with extremely low W/Si atomic ratios (≤1/80) exhibit excellent catalytic performance in the hydrogenolysis of glycerol to 1,3-PDO. In particular, a Pt/W–SBA-15 catalyst with the W/Si ratio of as low as 1/640 (Pt/W–SBA-15(1/640)) gave rise to the highest 1,3-PDO selectivity of 70.8% at a high glycerol conversion of 86.8% and thus afforded the highest yield of 1,3-PDO of 61.5%. A combination of characterization techniques evidenced that tungsten was homogeneously incorporated into SBA-15 in the form of isolated tetragonal WO4 and only displayed Lewis acidity. The particle size of Pt evolved in a reverse volcanic curve with the W/Si ratio, with the smallest size being observed for Pt/W–SBA-15(1/640). Control experiments indicated strong synergy between Pt nanoparticles (NPs) and WO4 in the hydrogenolysis of glycerol. A probe reaction suggested that Brønsted acid sites were generated in situ on the Pt/W–SBA-15 catalysts in a H2 atmosphere by the reaction between WO4 and spillover H atoms from the Pt NPs. It is plausible that the hydrided WO4 functioned as a highly selective active centre in the hydrogenolysis of glycerol to 1,3-PDO, whereas the Pt NPs played the role of a reservoir of spillover H atoms. Thus, a good match between the isolated WO4 and the small Pt NPs was responsible for the superior catalytic performance of Pt/W–SBA-15(1/640). [ABSTRACT FROM AUTHOR]

Oxidized starch-graft-poly(styrene-butyl acrylate)[OS-g-P(ST-BA)] latex with core-shell structure was synthesized by the graft copolymerization of OS with ST and n-butyl acrylate (BA) via emulsion polymerization. A three-level, four-variable Box-Behnken design was employed to investigate the effects of the concentration of OS, initiator, monomers, and temperature on the graft copolymerization. The significance of variables and their interactions were analyzed using analysis of variance and the model's significance was confirmed. The OS-g-P(ST-BA) was characterized by FTIR, TEM, DSC, and dynamic light scattering. The core-shell structure of OS-g-P(ST-BA) particle was clearly shown in TEM micrographs and confirmed by DSC analysis. Application of the OS-g-P(ST-BA) latex as a binder in paper coating improved the gloss, print gloss, and picking resistance of coated paper. [ABSTRACT FROM AUTHOR]

Graft copolymerization of styrene andn-butyl acrylate onto enzymatically degraded starch was carried out via surfactant-free emulsion polymerization. The cassava starch was degraded by α-amylase before copolymerization, which greatly enhanced the starch content in copolymer. A series of latexes with small particle size, narrow size distribution, and high stability were prepared. The effect of starch degradation on graft copolymerization was investigated. High grafting efficiency was obtained. The application test of the latex showed that the surface strength of coated paper was improved, and all the other properties are very close to those of paper coated with conventional styrene-acrylate latex. [ABSTRACT FROM AUTHOR]

[Display omitted] • The Pt/W-MCFs catalysts with different cell size and window size were prepared. • The W species were single-sited and tetrahedrally coordinated. • The content of the WV species evolved in parallel with that of the Pt2+ species. • The optimal Pt/W-MCFs catalyst gave a high 1,3-PDO yield of 63 %. • The WV species close to the Pt NPs may facilitate the immediate formation of 1,3-PDO. By varying the mass ratio of the swelling agent 1,3,5-trimethylbenzene (TMB) to the template P123 during the synthesis of the W-MCFs, we prepared a series of tungsten-doped siliceous mesocellular foams (W-MCFs) supported Pt catalysts (Pt/W-MCFs). In glycerol hydrogenolysis, the Pt/W-MCFs catalysts were highly active and selective to 1,3-propanediol (1,3-PDO), attributable to the 3-dimensional continuous large pore structure of the W-MCFs that facilitates the entry of the reactant and the escape of the product. Among the Pt/W-MCFs catalysts, the Pt/W-1.5MCFs catalyst with the TMB/P123 ratio of 1.5 exhibited the best activity and 1,3-PDO selectivity. Remarkably, the Pt/W-1.5MCFs catalyst afforded a high 1,3-PDO selectivity of 65 % at high glycerol conversion, thus rendering the highest 1,3-PDO yield of 63 %. The synergy between the Pt nanoparticles and the single-sited tetrahedral WVO 4 species at the metal–oxide interface is proposed to be responsible for the differences in the catalytic performances among the Pt/W-MCFs catalysts. [ABSTRACT FROM AUTHOR]

Abstract: In order to study long-term frequency and voltage dynamics of interconnected power systems under cascading events, the paper has developed a proper mathematical model and simulation algorithm for it with network structure preserved. Similar to the traditional dynamic power flow, the proposed model assumes that the system has survived in the transient stability and has enough damping torque. Therefore, the relative swings among generator rotors in one area will be neglected in long-term dynamics; and each control area is assumed to have a uniform frequency, represented by its area center of inertia (COI). Fast decoupled method has been extended to solve the structure-preserved multi-area network equations. Computer test results from a modified IEEE30-bus power system demonstrate the validity and effectiveness of the proposed model and algorithm. The work establishes a simulation platform for future study on long-term frequency and voltage stability control strategy and coordination of interconnected power systems. [Copyright &y& Elsevier]

Recent advances in signal processing methodologies have spawned the way for a high-speed home network power-line communication (PLC) system. In this paper, a novel signal processing method based on wavelet packet analysis is proposed to combat the adverse communication environment over power lines. A comparison research between wavelet transform and wavelet packet transform is presented. Since wavelet packet decomposition can provide more precise frequency resolution than wavelet decomposition, this paper proposes to use the wavelet packet analysis to deal with the highly polluted PLC communication signal. A hardware structure for the PLC system is presented as an experimental platform for sampling an actual communication signal. Simulation results based on these kinds of actual communication signals show the effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]

As the technique of orthogonal frequency-division multiplexing (OFDM) has the ability to overcome the effect of multipath and to obtain high spectral efficiency of the communication channel, it is generally considered as one of the most effective methods to realize the high-speed digital communication system over the low-voltage powerline. This paper proposes a novel OFDM method, in which the cosine carriers of the conventional OFDM system are replaced with the orthonormal wavelets. A quantitative index used to measure the multipath interference, including the intersymbol interference (ISI) and the interchannel interference (ICI), is induced with a filter bank-based multicarrier transmission system model. The effectiveness of the proposed OFDM over the conventional OFDM in reducing both the ISI and the ICI is verified on a model obtained from the measurements of a practical low-voltage powerline communication channel. [ABSTRACT FROM AUTHOR]

The low-voltage powerline communication (PLC net- work) is a technical and attractive innovation in the field of communication. PLC utilities can support energy distribution and provide a pipe for high-speed reliable communication traffic. Wide business opportunities can then be expected. Rut the question that re- mains is how to make the PLC network a commercial reality in the competitive broadband market. The low-voltage electrical network is an unfriendly environment and several factors inherent to the PLC concept itself present technical challenges to using it for data communication. Besides interference and low signaling impedance, PLC transmitters also require a highly linear operating environment. In this paper, a coupling unit topology and design methodology, which could provide gain equalization and wideband mitigation of the effects of low-impedance loads on PLC at the frequency ranging from 0.1 to 30 MHz are presented. Maximization of the network signaling and implementation of a high-speed PLC-oriented system are main objectives for the present work. Some experimental measurements have been performed at residential and industrial environments in China. Motivations to conduct this experiment are given; some compromise was obtained and results are presented. [ABSTRACT FROM AUTHOR]

A novel approach based on the Lyapunov decomposition–aggregation method is developed to analyze shaft stability in power systems. The power system including the turbine-generator shaft, flux decay and voltage regulator is decomposed to two isolated subsystems: mechanical subsystem and electrical subsystem. The mechanical subsystem is converted to a standard Lure control system that is analyzed by an improved Lure Lyapunov function. The stability of the power system at the equilibrium points is discussed in detail. The stable operation region of the system is obtained. Case study demonstrates the effectiveness of the proposed method. This study has shown the potential benefits and validity of Lyapunov direct method in the shaft torsional oscillation analysis. [Copyright &y& Elsevier]

Lithium‐ion batteries (LIBs) suffer from energy loss and safety hazards under high‐rate conditions, because of the sluggish electrochemical kinetics and unstable interfacial passivation. Herein, a PC‐based electrolyte using weakly solvated solvent ethyl trifluoroacetate is developed to improve interfacial kinetics and stability in LIBs. A microsolvating competition is revealed in the bulk electrolyte, forming a loose Li+ coordination configuration with benign Li+ affinity and high ionic conductivity. Furthermore, an inorganic‐rich interphase is constructed on a graphite anode, affording smooth Li+ desolvation and reliable passivation. Consequently, the NCM622/graphite cell in PC‐based electrolyte shows improved cycling stability (82.2% after 200 cycles) and rate capability (83% at 4C compared to 0.1C) at a high‐voltage of 4.5 V, much better than those of EC‐based electrolyte (76.2% after 200 cycles and 74% at 4C). Additionally, the PC‐based electrolyte affords reversible operation at –40 °C while the EC‐based electrolyte fails at –40 °C. This work highlights the potential of solvation structure engineering for low‐energy‐barrier electrolyte. [ABSTRACT FROM AUTHOR]

Active lithium is directed extracted from retired lithium-ion batteries with optimized conditions utilizing polycyclic aromatic hydrocarbons and nonpolar ether solvent. Using the recovered lithium solution, LiFePO 4 with performance on par with commercial materials are synthesized. This recycling approach shows excellent economic benefits and practical prospects. [Display omitted] The flourishing expansion of the lithium-ion batteries (LIBs) market has led to a surge in the demand for lithium resources. Developing efficient recycling technologies for imminent large-scale retired LIBs can significantly facilitate the sustainable utilization of lithium resources. Here, we successfully extract active lithium from spent LIBs through a simple, efficient, and low-energy-consumption chemical leaching process at room temperature, using a solution comprised of polycyclic aromatic hydrocarbons and ether solvents. The mechanism of lithium extraction is elucidated by clarifying the relationship between the redox potential and extraction efficiency. More importantly, the reclaimed active lithium is directly employed to fabricate LiFePO 4 cathode with performance comparable to commercial materials. When implemented in 56 Ah prismatic cells, the cells deliver stable cycling properties with a capacity retention of ∼90% after 1200 cycles. Compared with the other strategies, this technical approach shows superior economic benefits and practical promise. It is anticipated that this method may redefine the recycling paradigm for retired LIBs and drive the sustainable development of industries. [ABSTRACT FROM AUTHOR]

Ni−rich cathodes are hopeful materials for advanced lithium−ion batteries (LIBs) due to high capacity. Nonetheless, the chemical crosstalk triggered by reactive oxygen (O*) represents a critical factor in thermal runaway (TR). Currently, there are few effective means to prevent this parasitic reaction. Here, inspired by the O* scavenging effect of β−carotene in living organisms, it is innovatively identified that β−carotene can impede TR by restraining the escape of O* during the thermal decomposition of nickel−rich cathodes. Using LiNi0.6Co0.2Mn0.2O2 as model and extending to higher nickel content cathodes (LiNi0.8Co0.1Mn0.1O2, LiNi0.9Co0.05Mn0.05O2), it is demonstrated that β−carotene can undergo an in situ oxygen copolymerization reaction to trapping O*, thereby attenuating chemical crosstalk. Additionally, the generated oxygen copolymer can also adjust band center of the O 2p orbitals of delithiated cathode, alleviating the charge compensation behavior of oxygen anions, and thus delaying the phase transition of charged LiNi0.8Co0.1Mn0.1O2. As a result, the TR trigger temperature of NCM811∣Graphite pouch cell is increased from 131.0 to 195.0 °C and maximum temperature is reduced from 657.8 to 412.4 °C. This work introduces a new and simple strategy for designing functional additives to block TR, offering a promising avenue for advancing the safety of LIBs. [ABSTRACT FROM AUTHOR]

Compared to traditional lithium‐ion batteries with liquid electrolytes, all‐solid‐state lithium batteries have attracted extensive attention due to their heightened safety and energy density. Lithium argyrodite materials are promising solid electrolytes (SE) due to their high ionic conductivity, low grain boundary resistance, and favorable mechanical properties. However, the poor chemical/electrochemical stability of lithium argyrodite electrolytes toward the bare lithium metal anode inhibits their applications in all‐solid‐state lithium metal batteries (ASSLMBs). Here, Li‐SnF2 composite anodeswas used to induce the formation of solid electrolyte interphase (SEI) composed of LiCl, LiF, and Li22Sn5 at the Li/SE interface. The high interface energy barriers for LiF and LiCl induces the uniform deposition of lithium ions, thus hindering the growth of lithium dendrites. Meanwhile, the fast Li‐ion diffusion coefficient of the Li22Sn5 alloy accelerates Li‐ion migration across the interface section. The symmetrical cell exhibits stable cycling performance over long durations over 300 h at 0.5 mA cm−2. Moreover, the LiNbO3@NCM712/Li5.5PS4.5Cl1.5/Li‐10%SnF2 battery delivers a high initial discharge capacity of 170.9 mAh g−1 at 0.1C and retains 72.9% of its original capacity after 500 cycles at 0.5C. The facial approach for Li‐SnF2 composite anode enables the production of ASSLMBs with superior electrochemical performance. [ABSTRACT FROM AUTHOR]

Proposes a method for the design of an optimal fuzzy logic excitation controller for a generating unit. Important aspects in the performance of the fuzzy logic controller system; Method for design of an optimal fuzzy logic control; Problems with the conventional design method analyzed.

Analyzes the problems existing in the neural network based on-line self-learning control system. Principles of self-learning; Self-learning algorithm; Design of the self-learning power system stabilizer (PSS); Simulation results; Conclusions.

The Li5.5PS4.5Cl1.5 electrolyte gains significant attention due to its ultrahigh ionic conductivity and cost-effectiveness in halogen-rich lithium argyrodite solid electrolytes. The conventional synthetic method for obtaining the electrolyte involves mechanical milling followed by post-annealing. However, these synthesis methods typically involve high milling speeds, elevated temperatures, and prolonged durations, resulting in both high energy consumption and potential damage to the electrolyte. In this study, we successfully obtained Li5.5PS4.5Cl1.5 with a high conductivity of 7.92 mS cm−1 using a milling speed of 400 rpm and annealing at 400 °C for 5 hours. When incorporated into a Li4Ti5O12-based all-solid-state battery, this electrolyte demonstrates stable cycling performance across varying temperatures. [ABSTRACT FROM AUTHOR]

Power flow studies in traditional power systems aim to uncover the stationary relationship between voltage amplitude and phase and active and reactive powers; they are important for both stationary and dynamic power system analysis. With the increasing penetration of large-scale power electronics devices including renewable generations interfaced with converters, the power systems become gradually power-electronics-dominant and correspondingly their dynamical behavior changes substantially. Due to the fast dynamics of converters, such as AC current controller, the quasi-stationary state approximation, which has been widely used in power systems, is no longer appropriate and should be reexamined. In this paper, for a better description of network characteristics, we develop a novel concept of dynamic power flow and uncover an explicit dynamic relation between the instantaneous powers and the voltage vectors. This mathematical relation has been well verified by simulations on transient analysis of a small power-electronics-based power system, and a small-signal frequency-domain stability analysis of a voltage source converter connected to an infinitely strong bus. These results demonstrate the applicability of the proposed method and shed an improved light on our understanding of power-electronics-dominant power systems, whose dynamical nature remains obscure. [ABSTRACT FROM AUTHOR]

The operation of lithium‐ion batteries (LIBs) at low temperatures (<−20 °C) is hindered by the low conductivity and high viscosity of conventional carbonate electrolytes. Methyl acetate (MA) has proven to be a competitive low‐temperature electrolyte solvent with low viscosity and low freezing point, but its interfacial stability is poor and remains elusive until now. Here, it is revealed thaat the reductive stability of MA‐based electrolytes is fundamentally governed by the anion‐prevailed solvation structure. Based on this framework, fluorobenzene is employed in the electrolyte to promote the entry of anions into the solvation shell via dipole‐dipole interactions and the generation of free MA, thus enhancing the lowest unoccupied molecular orbital energy of MA. The designed electrolyte enables LiCoO2 (LCO)/graphite cells to exhibit excellent cycling performance at −20 °C (90% retention after 1000 cycles at 1 C) and to remain 91% of their room‐temperature capacity at a super‐low temperature of −60 °C at 0.05 C. Thanks to the plentiful free MA, this electrolyte has a high conductivity (2.61 mS cm−1) at −60 °C and allows LCO/graphite cell to charge at −60 °C. This study offers the possibility of practical applications for those solvents with poor reductive stability and provides new approaches to designing advanced electrolytes for low‐temperature applications. [ABSTRACT FROM AUTHOR]

While recent work demonstrates the advantages of weakly solvating solvents in enhancing the cyclability of LMBs, both new designs and design strategies for high performance weakly solvating solvent, especially physicochemical properties, are still lacking. Here, we propose a molecular design to tune the solvating power and physicochemical properties of non‐fluorinated ether solvent. The resulting cyclopentylmethyl ether (CPME) have a weak solvating power and wide liquid‐phase temperature range. By optimizing the salt concentration, the CE is further promoted to 99.4 %. Besides, the improved electrochemical performance of Li−S battery in CPME‐based electrolytes is obtained at −20 °C. The Li||LFP (17.6 mg cm−2) battery with developed electrolyte maintains >90 % of the original capacity over 400 cycles. Our design concept for solvent molecule provides a promising pathway to non‐fluorinated electrolytes with weakly solvating power and wide temperature window for high‐energy‐density LMBs. [ABSTRACT FROM AUTHOR]

While recent work demonstrates the advantages of weakly solvating solvents in enhancing the cyclability of LMBs, both new designs and design strategies for high performance weakly solvating solvent, especially physicochemical properties, are still lacking. Here, we propose a molecular design to tune the solvating power and physicochemical properties of non‐fluorinated ether solvent. The resulting cyclopentylmethyl ether (CPME) have a weak solvating power and wide liquid‐phase temperature range. By optimizing the salt concentration, the CE is further promoted to 99.4 %. Besides, the improved electrochemical performance of Li−S battery in CPME‐based electrolytes is obtained at −20 °C. The Li||LFP (17.6 mg cm−2) battery with developed electrolyte maintains >90 % of the original capacity over 400 cycles. Our design concept for solvent molecule provides a promising pathway to non‐fluorinated electrolytes with weakly solvating power and wide temperature window for high‐energy‐density LMBs. [ABSTRACT FROM AUTHOR]

Despite wide‐temperature tolerance and high‐voltage compatibility, employing propylene carbonate (PC) as electrolyte in lithium‐ion batteries (LIBs) is hampered by solvent co‐intercalation and graphite exfoliation due to incompetent solvent‐derived solid electrolyte interphase (SEI). Herein, trifluoromethylbenzene (PhCF3), featuring both specific adsorption and anion attraction, is utilized to regulate the interfacial behaviors and construct anion‐induced SEI at low Li salts' concentration (<1 m). The adsorbed PhCF3, showing surfactant effect on graphite surface, induces preferential accumulation and facilitated decomposition of bis(fluorosulfonyl)imide anions (FSI−) based on the adsorption–attraction–reduction mechanism. As a result, PhCF3 successfully ameliorates graphite exfoliation‐induced cell failure in PC‐based electrolyte and enables the practical operation of NCM613/graphite pouch cell with high reversibility at 4.35 V (96% capacity retention over 300 cycles at 0.5 C). This work constructs stable anion‐derived SEI at low concentration of Li salt by regulating anions–co‐solvents interaction and electrode/electrolyte interfacial chemistries. [ABSTRACT FROM AUTHOR]

Li 10 GeP 2 S 12 shows great potential as solid electrolytes for solid-state batteries due to its ultrahigh Li-ion conductivity. However, the high cost of Ge and the poor stability limit its applications. Replacing Ge with Sn can significantly lower the cost and maintains the high conductivity, while the corresponding Li 10 SnP 2 S 12 still suffers the low interfacial stability with the bare high voltage layered oxide cathodes. Herein, Li 10 SnP 2 S 12 with high Li-ion conductivity up to 4.79 mS cm−1 has been synthesized. All-solid-state battery using the cathode consisting of bare LiNi 0.6 Co 0.2 Mn 0.2 O 2 and Li 10 SnP 2 S 12 shows low capacities and poor cyclability due to side reactions between those two particles. To improve the interfacial stability, a highly conductive Li 3 InCl 6 electrolyte is introduced both in the cathode mixture and between the cathode layer and Li 10 SnP 2 S 12 solid electrolyte layer. This new configuration delivers superior electrochemical performances at different operating temperatures. It delivers high initial discharge capacities of 176.1 mAh g−1, 186.9 mAh g−1, and 73.7 mAh g−1 at 0.1C when operated at room temperature, 60 oC, and −20 oC, respectively. The superior battery performances are attributed to the excellent electrochemical stability of Li 3 InCl 6 electrolyte towards bare LiNi 0.6 Co 0.2 Mn 0.2 O 2 cathode. This work provides a guideline to design Li 10 SnP 2 S 12 -based all-solid-state lithium batteries with high energy density and long span life. [ABSTRACT FROM AUTHOR]

The self‐exothermic in early stage of thermal runaway (TR) is blasting‐fuse for Li‐ion battery safety issues. The exothermic reaction between lithiated graphite (LiCx) and electrolyte accounts for onset of this behavior. However, preventing the deleterious reaction still encounters hurdles. Here, we manage to inhibit this reaction by passivating LiCx in real time via targeted repair of SEI. It is shown that 1,3,5‐trimethyl‐1,3,5‐tris(3,3,3‐trifluoropropyl)cyclotrisiloxane (D3F) can be triggered by LiCx to undergo ring‐opening polymerization at elevated temperature, so as to targeted repair of fractured SEI. Due to the high thermal stability of polymerized D3F, exothermic reaction between LiCx and electrolyte is inhibited. As a result, the self‐exothermic and TR trigger temperatures of pouch cell are increased from 159.6 and 194.2 °C to 300.5 and 329.7 °C. This work opens up a new avenue for designing functional additives to block initial exothermal reaction and inhibit TR in early stage. [ABSTRACT FROM AUTHOR]

The self‐exothermic in early stage of thermal runaway (TR) is blasting‐fuse for Li‐ion battery safety issues. The exothermic reaction between lithiated graphite (LiCx) and electrolyte accounts for onset of this behavior. However, preventing the deleterious reaction still encounters hurdles. Here, we manage to inhibit this reaction by passivating LiCx in real time via targeted repair of SEI. It is shown that 1,3,5‐trimethyl‐1,3,5‐tris(3,3,3‐trifluoropropyl)cyclotrisiloxane (D3F) can be triggered by LiCx to undergo ring‐opening polymerization at elevated temperature, so as to targeted repair of fractured SEI. Due to the high thermal stability of polymerized D3F, exothermic reaction between LiCx and electrolyte is inhibited. As a result, the self‐exothermic and TR trigger temperatures of pouch cell are increased from 159.6 and 194.2 °C to 300.5 and 329.7 °C. This work opens up a new avenue for designing functional additives to block initial exothermal reaction and inhibit TR in early stage. [ABSTRACT FROM AUTHOR]

Fluorinated solvents emerge as a promising strategy to improve performance of lithium metal batteries (LMBs). However, most of them are prone to produce corrosive HF and deteriorate electrode interface, inducing cathode‐to‐anode detrimental crossover of transition metal‐ions. Here, fluorinated aromatic hydrocarbons in dimethyl carbonate (DMC)‐based diluted highly concentrated electrolyte (DHCE) are employed to juggle formation of HF and LiF, enabling stable cycling of high‐voltage LiNi0.7Co0.1Mn0.2O2 (NCM712) and LiCoO2 (LCO). The nature of aromatics in this carbonate‐based DHCE makes them difficult to undergo β‐hydrogen assisted defluorination, evidencing by the high energy barrier and high bond energy of β‐sites hydrogen. The advanced DHCE restrains HF formation but strengthens LiF formation, which not only suppresses impedance growth, transition‐metal dissolution, and stress crack on the cathode, but achieves highly reversible Li stripping/plating with an outstanding average Coulombic efficiency up to 99.3%. The Li||NCM712 cell and Li||LCO cell both exhibits superior cycling stability at high operation voltage. Even under stringent conditions, the 4.4 V Li||NCM712 full battery retains >95% of the initial capacity over 100 cycles, advancing practical high‐voltage LMBs. This study designs an efficient electrolyte that generates robust electrode/electrolyte interphases and restrains by‐products formation spontaneously, thus shedding new light on electrolyte toward applicable LMBs. [ABSTRACT FROM AUTHOR]

The advancements of lithium‐ion batteries indubitably call for advanced electrolytes with superior environmental adaptability and long‐term stability. Propylene carbonate (PC) proves to be a competitive solvent with the high permittivity and wide‐liquid range, while the application is intrinsically hindered by the poor graphite compatibility and high viscosity. Here, a PC‐based electrolyte with wide‐temperature range is developed by tuning the strength and topology of the Li+‐PC interactions via non‐solvating interactions without altering the solvation structure. Thus, the problem of graphite exfoliation caused by Li+‐PC co‐intercalation can be successfully mitigated. Consequently, such electrolyte shows compatibility with both graphite and high‐nickel cathode, exhibiting an expanded liquid range from −90 to 90 °C. This work, breaking from the traditional EC‐based formula, provides a new strategy for designing PC‐enabled electrolyte featuring high performance, wide‐temperature compatibility, and sustainability [ABSTRACT FROM AUTHOR]

Fluorobenzene (FB) is identified as a well competitive candidate co-solvent due to the low-density and low-cost, but as a hydrocarbon, the high flammability may limit its application. Based on the DHCE concepts and the strategy of combining internal-external flame retardant, we successfully solve the flammable problem of FB and develop a non-flammable electrolyte with specific solvent structure. [Display omitted] Lithium-ion batteries with Ni-rich cathode and flammable carbonate electrolytes are breeding severe safety concerns which hinds their application in electric vehicles. Herein, by introducing the fluorobenzene (FB) with low-density and low-cost as a cosolvent and bridge solvents in triethyl phosphate (TEP)-based diluted high-concentration electrolytes (DHCEs) system, we design a non-flammable electrolyte with a special solvation structure containing internal-external flame retardants. This non-flammable electrolyte not only solves successfully the incompatibility problem of TEP-based electrolyte to the Li-metal anode (LMA) and the graphite (Gr) anode, but also ensures the stable cycling of Li||LiNi 0.7 Co 0. 1 Mn 0. 2 O 2 (86% capacity retention after 120 cycles) and Gr|| LiNi 0.7 Co 0. 1 Mn 0. 2 O 2 (75% capacity retention after 200 cycles) full cells. Such design opens up a new window for developing new electrolyte systems and building safer high-energy-density batteries. [ABSTRACT FROM AUTHOR]

This paper proposes a multiport dc–dc autotransformer (multiport dc auto) that is used to interconnect multiple HVDC systems with different voltage levels. The multiport dc auto is able to reduce 50–80% the converter cost compared with conventional dc–ac–dc technology. Different from the conventional dc–ac–dc technology using magnetic coupling at the ac sides of the converters, there is direct electrical connection between the interconnected dc systems in the multiport dc auto. Such direct electrical interconnection significantly reduces the used power converters in the multiport dc auto. Taking interconnecting a ±250, ±320, and ±400 kV dc system with the rated exporting/importing dc power at each of the dc system being 500, 1000, and 1500 MW as an example, the conventional multiport dc–ac–dc technology requires a total of 3000 MW power converters while only 775 MW power converter is required in the multiport dc–dc autotransformer. The required power converter in the multiport dc–dc autotransformer is only 26% of the converter used in the conventional multiport dc–ac–dc technology. Cost and operating power loss is therefore significantly reduced. [ABSTRACT FROM AUTHOR]

Chlorine-rich argyrodite Li 5.5 PS 4.5 Cl 1.5 with low-cost and high ionic conductivity displays great potential as a solid electrolyte for solid-state battery. However, poor compatibility with bare high-voltage cathode limits its applications. Here, the Li 2 ZrO 3 coating and Li 3 InCl 6 isolating layer strategy are employed to mitigate the interfacial instability between Li 5.5 PS 4.5 Cl 1.5 electrolytes and LiNi 0.7 Co 0.1 Mn 0.2 O 2 materials, respectively. A diversified combination of two strategies is applied to construct all-solid-state batteries with a long lifespan and high energy density. Electrochemical performance results indicate that introducing Li 3 InCl 6 electrolyte in the cathode mixture yields high discharge capacities at beginning and then suffers rapid capacity degradation during extended cycling. In contrast, the assembled Li 2 ZrO 3 @LiNi 0.7 Co 0.1 Mn 0.2 O 2 /Li 5.5 PS 4.5 Cl 1.5 /Li–In battery delivers slightly lower capacities and superior capacity retention. Multiple characterization methods are employed to unravel the mechanism behind battery performance differences. The poor cycle performance of Li 3 InCl 6 -involved solid-state battery configurations is partially associated with the decomposition of Li 3 InCl 6 in the cathode mixture. The Li 2 ZrO 3 coating layer mitigates the side reaction between LiNi 0.7 Co 0.1 Mn 0.2 O 2 and Li 3 InCl 6 , resulting in enhanced capacities and improved cyclability. Furthermore, the interfacial instability between Li 3 InCl 6 and Li 5.5 PS 4.5 Cl 1.5 electrolytes leads to the poor cycling performance of batteries containing the Li 3 InCl 6 /Li 5.5 PS 4.5 Cl 1.5 bilayer structure. This work offers a comprehensive guide for designing high-performances all-solid-state lithium batteries. • Li 2 ZrO 3 coating layer is introduced to alleviate instability of cathode interface. • Li 3 InCl 6 separator layer is utilized to isolate cathode and Li 5.5 PS 4.5 Cl 1.5. • The advantages of Li 2 ZrO 3 and Li 3 InCl 6 protecting strategies have been studied. • Two protection strategies are combined to improve battery performance. • The instability between Li 3 InCl 6 and Li 5.5 PS 4.5 Cl 1.5 affects battery performance. [ABSTRACT FROM AUTHOR]

Thermal runaway introduces a significant challenge in the widespread application of lithium-ion batteries, necessitating advanced early-warning technologies to ensure safety, particularly during charging. Only monitoring the temperature and voltage limit the performance of diagnostic algorithms. The expansion behavior of batteries, which is linked to their operating status, offers a vital indicator of safety. In this study, the evolution of multidimensional signals during overcharging experiments at different current rates is comprehensively investigated. The result shows that the abnormal expansion force can be detected at temperatures as low as 35.4 °C, which achieves an early warning signal 11 min earlier than the onset of battery thermal runaway. The effect of charging rate on battery safety is comprehensively analyzed, showing that the time interval between the warning signal of the expansion force and temperature increases steadily from 151 s to 682 s as the charging rate decreases. However, the charging rate hardly affects the stage of charge boundary of venting, which is around ±118 %. These insights are crucial for understanding early warning mechanisms in overcharged batteries, offering valuable guidance for enhancing the safety of electric vehicles and energy storage systems. • Force signal offers early warning 682 s before battery thermal runaway. • Abnormal expansion force can be detected at a minimum temperature of 35.4 °C. • Effect of charging rate on battery safety is comprehensively analyzed. • Charging rate hardly affects stage of charge boundary of venting. • Force signal can be utilized as an overcharge warning indicator at high rates. [ABSTRACT FROM AUTHOR]

The characteristics of thermal runaway in batteries exhibit significant differences depending on their states of charge (SOCs), posing considerable challenges in accurate and timely warning for thermal runaway accidents. This paper conducts an experimental investigation into the external expansion force, voltage, and temperature behaviours of batteries under different SOCs under thermal abuse scenarios. The expansion force signal was found first to exhibit abnormal characteristics (with an indicator value of 5 N/s), offering an earlier warning signal >642 s prior to thermal runaway, when the battery back temperature is merely approximately 318.15 K. To analyse the main causes of abnormal expansion, ultrasonic nondestructive tests were performed and suggested that a higher SOC intensify the side reactions and cause gas generation inside batteries. Notably, compared to normal-charged batteries (0% ≤ SOC ≤ 100%), over-charged batteries (SOC > 100%) are more sensitive to expansion force than normal-charged batteries. Furthermore, compared with voltage and temperature signals, the early warning time of the expansion force rises with the increase in the SOC of an overcharged battery, in contrast to normal-charged batteries. Finally, a novel hazard classification safety warning strategy for battery failure is effectively proposed. These novel findings hold substantial practical implications for creating more accurate early warning systems for battery thermal runaway, enhancing the safe and reliable operation of battery systems. • Effect of SOC on multidimensional signal evolution is comprehensively revealed. • Expansion force can serve as an early warning signal of battery failure. • Expansion force evolution of batteries with different states of charge is revealed. • Nondestructive tests are conducted to analyse the main causes of abnormal expansion. • A novel warning strategy with hazard classification for battery failure is proposed. [ABSTRACT FROM AUTHOR]

All-solid-state lithium metal batteries (ASSLMBs) hold tremendous promise as next-generation energy storage devices due to their remarkable energy densities. Nevertheless, uncontrolled growth of lithium dendrites resulting from nonuniform deposition and significant volume expansion hinders the commercial application of ASSLMBs. Herein, we designed an AgPF 6 modified lithium composite anode to stabilize the interface between the lithium metal anode and Li 5.5 PS 4.5 Cl 1.5 electrolytes. The optimal AgPF 6 modified lithium composite accelerates Li diffusion within bulk lithium anode and facilitates the uniform deposition for lithium metal during the electrochemical process due to the generation of LiF-interface and Li–Ag alloy, which restricts the accumulation of inactive lithium. The enhanced compatibility between Li metal and sulfide electrolyte have been confirmed in both symmetric cells and ASSLMBs. The assembled AgPF 6 @Li/Li 5.5 AgPS 4.5 Cl 1.5 /AgPF 6 @Li cells shows a high critical current density value of 2.1 mA cm−2 and a stable lithium stripping/platting behavior up to 400 h at 0.1 mA cm−2. The LiNi 0.6 Mn 0.2 Co 0.2 O 2 /Li 5.5 PS 4.5 Cl 1.5 /AgPF 6 @Li battery delivers an initial discharge capacity of 113.5 mAh g−1 at 0.5C with superior capacity retention of 77.0% after 500 cycles at room temperature. This work proposes an effective strategy in designing composite lithium metal employing in sulfide-based ASSLMBs to achieve favorable energy density and excellent cyclability. The kinetic instability between lithium and sulfide electrolyte hinders the practical feasibility of all-solid-state batteries. A homogeneous Li–F–Ag composite lithium anode is formed via the conversion reaction, the optimal Ag–F modified lithium composite accelerates Li+ diffusion and facilitates the uniform deposition of lithium metal during the electrochemical process due to the generation of LiF-interface and Li–Ag alloy, which restricts the accumulation of inactive lithium. [Display omitted] • AgPF 6 modification strategy on the lithium metal exhibits enhanced compatibility with the Li 5.5 PS 4.5 Cl 1.5 electrolytes. • The assembled NCM622/Li 5.5 PS 4.5 Cl 1.5 /AgPF 6 @Li all-solid-state lithium metal battery delivers a high initial discharge capacity of 113.5 mAh g−1 at 0.5C and maintains 77% of its original capacity after 500 cycles. • The optimal Ag–F modified lithium composite accelerates Li+ diffusion and facilitates the uniform deposition of lithium metal during the electrochemical process dur to the generation of LiF-interface and Li–Ag alloy. [ABSTRACT FROM AUTHOR]

With widespread application of voltage source converter (VSC) as a key energy-conversion power electronic device by using the phase-locked loop (PLL) technique for synchronization, the system dynamics has become much complicated. In this paper, the nonlinear dynamics and transient stability of the PLL-based VSC system are investigated, within a unified framework of the (normalized) generalized swing equation. It is found that there are three different types of bifurcation, including the generalized saddle-node, Hopf, and homoclinic bifurcations. Within the coexistence parameter region, the basin boundary of the stable equilibrium point shows either a closed-loop or a fish-like pattern. With the help of the equal area criterion (EAC), the transient stabilities under different transient disturbances including short circuit, voltage dip, and power rise are analyzed. Because the equivalent damping of the VSC is state-dependent, the theoretical results based on the EAC are examined. Furthermore, based on the analytical results from the generalized swing equation, the principle for all major transient stability enhancement methods is uncovered. All these findings are well verified by extensive electromagnetic transient simulations. Therefore, the generalized swing equation provides a deeper physical insight and plays a crucial role in transient stability problems in power-electronic-dominated power systems, similar to the swing equation in traditional power systems. [ABSTRACT FROM AUTHOR]

High‐energy density and ultra‐long cycling lifespan are of great significance in pursuit of practical lithium–sulfur (Li‐S) batteries, in which the construction of ultrathick, high‐areal‐capacity, and stable‐cycling sulfur cathodes remains challenging. Here, a unique layered reinforced concrete structure (LRCS) is reported by integrating an ice‐template method with incorporating carbon fibers in the thick electrodes for Li‐S batteries. The LRCS enables aligned through‐channel structure and intertwined conductive network, which lead to both fast kinetics of ions/electrons transport and strengthened electrode integrity to tolerate the volume change during cycling and the dimensional deformation under a high compaction density. Benefiting from the unique structure, the ultra‐thick Se0.05S0.95 @ pPAN cathode (20.2 mg cm−2) delivers a high capacity of 10 mAh cm−2 and excellent capacity retention of 80.8% over 140 cycles at a low electrolyte‐to‐sulfur ratio of 2 and a negative‐to‐positive capacity ratio of 2.7, corresponding to a calculated energy density of 390 Wh kg−1. This investigation not only provides guidance for the design of thick sulfur electrodes but also paves the way for the development of practical Li‐S batteries. [ABSTRACT FROM AUTHOR]

High‐energy density and ultra‐long cycling lifespan are of great significance in pursuit of practical lithium–sulfur (Li‐S) batteries, in which the construction of ultrathick, high‐areal‐capacity, and stable‐cycling sulfur cathodes remains challenging. Here, a unique layered reinforced concrete structure (LRCS) is reported by integrating an ice‐template method with incorporating carbon fibers in the thick electrodes for Li‐S batteries. The LRCS enables aligned through‐channel structure and intertwined conductive network, which lead to both fast kinetics of ions/electrons transport and strengthened electrode integrity to tolerate the volume change during cycling and the dimensional deformation under a high compaction density. Benefiting from the unique structure, the ultra‐thick Se0.05S0.95 @ pPAN cathode (20.2 mg cm−2) delivers a high capacity of 10 mAh cm−2 and excellent capacity retention of 80.8% over 140 cycles at a low electrolyte‐to‐sulfur ratio of 2 and a negative‐to‐positive capacity ratio of 2.7, corresponding to a calculated energy density of 390 Wh kg−1. This investigation not only provides guidance for the design of thick sulfur electrodes but also paves the way for the development of practical Li‐S batteries. [ABSTRACT FROM AUTHOR]

Developing an optimal method for cellulose nanocrystals (CNCs) production is promising and sustainable. Hence, machine learning (ML) algorithms were applied to aid the CNC preparation and optimization with the consideration of related factors in hydrolysis process. The dataset collected from published literatures were used to train the ML models for prediction and optimization of CNC production by sulfuric acid hydrolysis of different cellulose sources. The gradient boosting decision tree algorithm was the best one for the yield prediction (R 2=0.86, RMSE=9.15), and for the crystallinity prediction (R 2=0.87, RSME=2.56). The acid concentration and cellulose source were identified as the most important features of yield and crystallinity prediction, respectively. Shapley additive explanation is used to visually interpret the ML model and the interaction effect of input features on yield. Then, the ML models were optimized and evaluated by experimental validation. The predicted CNC yield is 61 % at an acid concentration of 60 %, ratio of acid/cellulose of 8, temperature of 54 °C, and time of 50 min. The optimized result was experimentally validated and the CNC yield of 58.3 % with errors of less than 4.6 %. This study provides new perspectives and opportunities to understand and improve the preparation of CNCs. • Machine learning was applied to study, predict, and optimize the CNC production. • Machine learning models were successfully developed for yield prediction. • Gradient boosting decision tree has the best prediction performance. • The highest yield was 61 % at predicted points and was experimentally validated. • The SHAP was used to interpret the interaction effect of input features. [ABSTRACT FROM AUTHOR]

Cathode materials significantly affect the failure behavior of lithium-ion batteries, but there is a lack of comparative research on the multidimensional signal evolution for batteries with various cathode materials when subjected to thermal runaway (TR). This study investigates the effect of cathode materials on battery safety properties by conducting overheating and overcharging abuse experiments on LiNi x Co y Mn (1-x-y) O 2 (NCM 523, 622, and 811) as well as LiFePO 4 (LFP) batteries. The multidimensional signals, including expansion force, gas concentrations, temperature, and voltage, are comprehensively and quantitatively analyzed. The results demonstrate that expansion force shows the earliest anomalies regardless of the cathode material in both abuse conditions. Gas can be detected after venting, followed by significant anomalies in voltage and temperature. Additionally, under overheating conditions, LFP cells exhibit the longest TR warning time of 677 s. However, the force anomaly-based warning method is more suitable for low-nickel NCM cells under overcharging scenarios. Specifically, NCM 523 cells achieve an overcharging warning time of 992 s at temperatures as low as 42.9 °C, and hold the highest venting force of 9859 N and venting temperature at 114.1 °C. On this basis, a hierarchical warning strategy based on multidimensional signal fusion is proposed. This study provides valuable insights into TR early warning and safety management in LIBs with different cathode materials. • Effects of cathode materials on battery failure behaviors are evaluated. • Multidimensional signal evolution, particularly expansion force, is revealed. • LFP cells exhibit the best superiority to overheating with the longest warning time. • NCM 523 cells show the best endurance to overcharging with the longest warning time. • A hierarchical warning strategy based on multidimensional signal fusion is proposed. [ABSTRACT FROM AUTHOR]

Deep learning (DL) is effective in identifying the dominant instability mode (DIM) of power systems. However, regular supervised learning for training DL models requires a large number of training samples with accurate labels provided by power system experts, which is prohibitively costly in practice. To address this issue, this paper proposes a weakly supervised learning framework to train DL models for DIM identification based on cheap but potentially inaccurate (noisy) labels from non-expert engineers. The framework comprises two stages to mitigate the detrimental effects of label noise. At Stage I, an auxiliary model is proposed to intelligently detect detrimental noisy samples while preserving truly-labeled informative hard samples based on the entire training loss dynamics of base DL models. Then Stage II incorporates virtual adversarial training to utilize all samples, including noisy ones with labels removed, to train a smooth DIM identification model in a semi-supervised learning way. It can help further mitigate the effects of undetected label noise. Case studies are conducted on CEPRI 36-bus system and Northeast China Power System (2131 buses). The results verify that the proposed framework can tolerate high-intensity feature-(in)dependent label noise and build reliable DL models for DIM identification with significantly less reliance on experts. • Robust deep learning for power system dominant instability mode identification. • Two-stage weakly supervised learning to mitigate label noise from non-experts. • Noisy samples are detected while hard ones are preserved. • Virtual adversarial training is proposed to use noisy samples as unlabeled ones. • Intelligent dominant instability mode identification becomes more affordable. [Display omitted] [ABSTRACT FROM AUTHOR]

In actual microgrids (MGs) networks, the information exchange between distributed energy resources (DERs) agents may be subject to various types of measurement noises and effected by communication time delays. This article proposes a resilient distributed multiagent control scheme for ac MG networks subject to additive noise and time-delay disturbances. The proposed multiagent control scheme is composed of three distributed consensus protocols, which is able to synchronize the output voltages and frequencies of inverter-based DERs to their reference values and achieve the optimal active power-sharing property by a low bandwidth communication network with noise and time-delay disturbances in almost sure convergence. By means of the stochastic analysis tools and algebraic graph theory, distributed consensus control protocols are designed to be employed for the secondary control level of MGs. On this basis, we deduce the stability criteria of the closed-loop MG system under noise and time-delay disturbances. As a result, the proposed consensus protocols can well restore the voltage and frequency’s derivation produced at the primary control level, meanwhile, can well achieve the optimal power sharing even though there exist communication disturbances. Several simulation scenarios on an islanded MG network are provided to verify the proposed control protocols’ performance. [ABSTRACT FROM AUTHOR]

This paper proposes a real-time coordinated scheduling method for active distribution networks (ADNs) with soft open points (SOPs) and plug-in electric vehicles (PEVs) via multi-timescale framework under uncertainties. Specifically, this method is achieved with day-ahead pre-scheduling and intra-day corrective control stages by coordinating various flexible resources at different timescales. The day-ahead stage is designed to reduce operational cost, regulate voltage profile and avoid risk exposure through joint scheduling of traditional devices, SOPs and PEVs on hourly basis. In intra-day corrective control stage, an hour is further divided into two timescales. The slow-timescale scheduling (STS) aims to corrective coordination of SOPs and across-time-and-space energy transmission of PEVs, and nested within the STS, the fast-timescale scheduling optimally coordinates the active & reactive power of SOPs and PV inverters to handle fast voltage fluctuations as well as against real-time uncertainties. The formulated three models are all transformed into second-order cone programming problems via sample weighted average approximation (SWAA), linearization and conic relaxation, which can be thus efficiently solved. Case studies based on three modified distribution systems (including two IEEE test systems and one actual distribution network) are performed to verify the effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]

Abstract: This paper proposes a precise real-time wind speed estimation method and sensorless control for variable-speed variable-pitch wind turbine power generation system (WTPGS). The wind speed estimation is realized by a nonlinear input–output mapping extreme learning machine (ELM). A specific design characteristic of the wind turbine is used for improving the mapping accuracy with considering the variable pitch angle. Moreover, since the design is independent of the environmental air density, the proposed ELM wind speed estimation method is robust to the air density variations. The estimated wind speed is then used to determine the optimal rotational speed command for maximum power point tracking. A fast and effective ELM mapping based pitch controller is proposed too when the WTPGS operates in its high wind speed region. The ELM pitch controller can act much faster and more precise than conventional pitch controllers. Furthermore, the complicated design precess for the parameters of conventional pitch controllers will be avoided in the proposed method. The effectiveness of the proposed methods are verified both by simulations and experiments on a WTPGS installed with Permanent Magnet Synchronous Generator (PMSG). [Copyright &y& Elsevier]

Variation is one of the most important inherent characteristics of wind power. Very few common methods exist to quantify the variations. This presents difficulty for the security and efficiency operations of power systems if large-scale wind power is included. Based on the analysis results from the large amounts of field measurements from nine aggregated wind farms, it is found that the t location-scale distribution and the Laplace distribution are able to cope with this problem. A systemic methodology is proposed accordingly. Therefore, the characteristic of the wind-power variations could be appropriately represented. [ABSTRACT FROM PUBLISHER]

Abstract: This paper presents rigorous arguments on existence of chaos and an estimate of topological entropy in a simple power system by means of topological horseshoe theory and computer computations. [Copyright &y& Elsevier]