Electrothermal Model Based Remaining Charging Time Prediction of Lithium-Ion Batteries against Wide Temperature Range

Battery remaining charging time(RCT)prediction can facilitate charging management and alleviate mileage anxiety for electric vehicles(EVs).Also,it is of great significance to improve EV users’experience.However,the RCT for a lithiumion battery pack in EVs changes with temperature and other battery parameters.This study proposes an electrothermal model-based method to accurately predict battery RCT.Firstly,a characteristic battery cell is adopted to represent the battery pack,thus an equivalent circuit model(ECM)of the characteristic battery cell is established to describe the electrical behaviors of a battery pack.Secondly,an equivalent thermal model(ETM)of the battery pack is developed by considering the influence of ambient temperature,thermal management,and battery connectors in the battery pack to calculate the temperature which is then fed back to the ECM to realize electrothermal coupling.Finally,the RCT prediction method is proposed based on the electrothermal model and validated in the wide temperature range from-20℃to 45℃.The experimental results show that the prediction error of the RCT in the whole temperature range is less than 1.5%.

A CombustionModel for Explosive Charge Affected by a Bottom Gap in the Launch Environment

Launch safety of explosive charges has become an urgent problem to be solved by all countries in the world aslaunch situation of ammunition becomes consistentlyworse.However, the existing numericalmodels have differentdefects. This paper formulates an efficient computational model of the combustion of an explosive charge affectedby a bottom gap in the launch environment in the context of the material point method. The current temperatureis computed accurately from the heat balance equation, and different physical states of the explosive charges areconsidered through various equations of state. Microcracks in the explosive charges are described with respectto the viscoelastic statistical crackmechanics (Visco–SCRAM) model. Themethod for calculating the temperatureat the bottomof the explosive charge with respect to the bottomgap is described. Based on this combustionmodel,the temperature history of a Composition B (COMB) explosive charge in the presence of a bottom gap is obtainedduring the launch process of a 155-mm artillery. The simulation results show that the bottom gap thickness shouldbe no greater than 0.039 cm to ensure the safety of the COM B explosive charge in the launch environment. Thisconclusion is consistent with previous results and verifies the correctness of the proposed model. Ultimately, thispaper derives amathematical expression for themaximumtemperature of the COMB explosive chargewith respectto the bottomgap thickness (over the range of 0.00–0.039 cm), and establishes a quantitative evaluationmethod forthe launch safety of explosive charges.The research results provide some guidance for the assessment and detectionof explosive charge safety in complex launch environments.

Tight gas charging and accumulation mechanisms and mathematical model

The gas-water distribution and production heterogeneity of tight gas reservoirs have been summarized from experimental and geological observations, but the charging and accumulation mechanisms have not been examined quantitatively by mathematical model. The tight gas charging and accumulation mechanisms were revealed from a combination of physical simulation of nuclear magnetic resonance coupling displacement, numerical simulation considering material and mechanical equilibria, as well as actual geological observation. The results show that gas migrates into tight rocks to preferentially form a gas saturation stabilization zone near the source-reservoir interface. When the gas source is insufficient, gas saturation reduction zone and uncharged zone are formed in sequence from the source-reservoir interface. The better the source rock conditions with more gas expulsion volume and higher overpressure, the thicker the gas saturation stabilization and reduction zones, and the higher the overall gas saturation. When the source rock conditions are limited, the better the tight reservoir conditions with higher porosity and permeability as well as larger pore throat, the thinner the gas saturation stabilization and reduction zones, but the gas saturation is high. The sweet spot of tight gas is developed in the high-quality reservoir near the source rock, which often corresponds to the gas saturation stabilization zone. The numerical simulation results by mathematical model agree well with the physical simulation results by nuclear magnetic resonance coupling displacement, and reasonably explain the gas-water distribution and production pattern of deep reservoirs in the Xujiaweizi fault depression of the Songliao Basin and tight gas reservoirs in the Linxing-Huangfu area of the Ordos Basin.

Modeling the blast load induced by a close-in explosion considering cylindrical charge parameters

Structural damage is significantly influenced by the various parameters of a close-in explosion.To establish a close-in blast loading model for cylindrical charges according to these parameters,a series of field experiments and a systematic numerical analysis were conducted.A high-fidelity finite element model developed using AUTODYN was first validated using blast data collected from field tests conducted in this and previous studies.A quantitative analysis was then performed to determine the influence of the charge shape,aspect ratio(length to diameter),orientation,and detonation configuration on the characteristics and distributions of the blast loading(incident peak overpressure and impulse)according to scaled distance.The results revealed that the secondary peak overpressure generated by a cylindrical charge was mainly distributed along the axial direction and was smaller than the overpressure generated by an equivalent spherical charge.The effects of charge shape on the blast loading at 45°and 67.5°in the axial plane could be neglected at scaled distances greater than 2 m/kg^(1/3);the effect of aspect ratios greater than 2 on the peak overpressure in the 90°(radial)direction could be neglected at all scaled distances;and double-end detonation increased the radial blast loading by up to 60%compared to singleend detonation.Finally,an empirical cylindrical charge blast loading model was developed considering the influences of charge aspect ratio,orientation,and detonation configuration.The results obtained in this study can serve as a reference for the design of blast tests using cylindrical charges and aid engineers in the design of blast-resistant structures.

Controlling factors on the charging process of oil and gas in the eastern main sub-sag of the Baiyun Sag,Zhujiang River(Pearl River)Mouth Basin

The eastern main sub-sag(E-MSS)of the Baiyun Sag was the main zone for gas exploration in the deep-water area of the Zhujiang River(Pearl River)Mouth Basin at its early exploration stage,but the main goal of searching gas in this area was broken through by the successful exploration of the W3-2 and H34B volatile oil reservoirs,which provides a new insight for exploration of the Paleogene oil reservoirs in the E-MSS.Nevertheless,it is not clear on the distribution of“gas accumulated in the upper layer,oil accumulated in the lower layer”(Gas_(upper)-Oil_(lower))under the high heat flow,different source-rock beds,multi-stages of oil and gas charge,and multi-fluid phases,and not yet a definite understanding of the genetic relationship and formation mechanism among volatile oil,light oil and condensate gas reservoirs,and the migration and sequential charge model of oil and gas.These puzzles directly lead to the lack of a clear direction for oil exploration and drilling zone in this area.In this work,the PVT fluid phase,the origin of crude oil and condensate,the secondary alteration of oil and gas reservoirs,the evolution sequence of oil and gas formation,the phase state of oil and gas migration,and the configuration of fault activity were analyzed,which established the migration and accumulation model of Gas_(upper)-Oil_(lower)cocontrolled by source and heat,and fractionation controlled by facies in the E-MSS.Meanwhile,the fractionation evolution model among common black reservoirs,volatile reservoirs,condensate reservoirs and gas reservoirs is discussed,which proposed that the distribution pattern of Gas_(upper)-Oil_(lower)in the E-MSS is controlled by the generation attribute of oil and gas from source rocks,the difference of thermal evolution,and the fractionation controlled by phases after mixing the oil and gas.Overall,we suggest that residual oil reservoirs should be found in the lower strata of the discovered gas reservoirs in the oil-source fault and diapir-developed areas,while volatile oil reservoirs should be found in the deeper strata near the sag with no oil-source fault area.

A hybrid model for the charging process of the amorphous SiO_2 film in radio frequency microelectromechanical system capacitive switches

Charging is one of the most important reliability issues in radio frequency microelectro- mechanical systems （RF MEMS） capacitive switches since it makes the actuation voltage unstable. This paper proposes a hybrid model to describe the transient dielectric charging and discharging process in the defect-rich amorphous SiO2 RF MEMS capacitive switches and verifies experimentally. The hybrid model contains two parts according to two different charging mechanisms of the amorphous SiO2, which are the polarisation and charge injection. The models for polarisation and for charge injection are established, respectively. Analysis and experimental results show that polarisation is always effective, while the charge injection has a threshold electric field to the amorphous SiO2 film. Under different control voltage conditions, the hybrid model can accurately describe the experimental data.

Benefit allocation model of distributed photovoltaic power generation vehicle shed and energy storage charging pile based on integrated weighting-Shapley method

In this study,to develop a benefit-allocation model,in-depth analysis of a distributed photovoltaic-powergeneration carport and energy-storage charging-pile project was performed;the model was developed using Shapley integrated-empowerment benefit-distribution method.First,through literature survey and expert interview to identify the risk factors at various stages of the project,a dynamic risk-factor indicator system is developed.Second,to obtain a more meaningful risk-calculation result,the subjective and objective weights are combined,the weights of the risk factors at each stage are determined by the expert scoring method and entropy weight method,and the interest distribution model based on multi-dimensional risk factors is established.Finally,an example is used to verify the rationality of the method for the benefit distribution of the charging-pile project.The results of the example indicate that the limitations of the Shapley method can be reasonably avoided,and the applicability of the model for the benefit distribution of the charging-pile project is verified.

Analytical model of non-uniform charge distribution within the gated region of GaN HEMTs

A physics-based analytical expression that predicts the charge,electrical field and potential distributions along the gated region of the GaN HEMT channel has been developed.Unlike the gradual channel approximation(GCA),the proposed model considers the non-uniform variation of the concentration under the gated region as a function of terminal applied volt-ages.In addition,the model can capture the influence of mobility and channel temperature on the charge distribution trend.The comparison with the hydrodynamic(HD)numerical simulation showed a high agreement of the proposed model with numerical data for different bias conditions considering the self-heating and quantization of the electron concentration.The ana-lytical nature of the model allows us to reduce the computational and time cost of the simulation.Also,it can be used as a core expression to develop a complete physics-based transistorⅣmodel without GCA limitation.

基于CHARGE-AF模型评估减重术对心房颤动发生风险的影响

目的通过CHARGE-AF模型评估外科减重术对肥胖症患者心房颤动(房颤)发生风险的影响。方法纳入2016年8月至2020年5月期间入院拟行袖状胃切除术(LSG术)的肥胖症患者,收集并记录受试者行LSG术前及术后的相关病史、体格检查和心电图结果,根据CHARGE-AF模型和CHARGE-AF增强模型公式计算房颤发生风险。结果研究共纳入67例受试者,平均随访时间为11.11±5.51个月。LSG术后受试者的体重、收缩压、舒张压、降压药物服用率、糖尿病患病率、心肌肥厚发生率、PR间期<120 ms发生率均显著性降低。而抽烟率、心力衰竭(心衰)患病率、心肌梗死(心梗)患病率、PR间期>199 ms未发生显著性变化。根据CHARGE-AF模型公式计算,受试者房颤发生风险呈降低趋势,由(0.11±0.10)%降至(0.08±0.08)%,(P=0.07)。根据CHARGE-AF增强模型计算,受试者房颤发生风险显著降低,由(0.12±0.12)%降至(0.08±0.08)%,(P<0.05)。将体重变量单因素纳入模型计算出受试者房颤发生风险显著降低(P<0.001)。结论肥胖症患者在减重术后房颤发生的可能危险因素(如体重、血压、心室肥厚等)均得到显著改善,房颤的发生风险显著降低。

Electron Shape Calculated for the Dual-Charge Dual-Mass Model

A model for the internal structure of the electron using classical physics equations has been previously published by the author. The model employs both positive and negative charges and positive and negative masses. The internal attributes of the electron structure were calculated for both ring and spherical shapes. Further examination of the model reveals an instability for the ring shape. The spherical shape appears to be stable, but relies on tensile or compressive forces of the electron material for stability. The model is modified in this document to eliminate the dependency on material forces. Uniform stability is provided solely by balancing electrical and centrifugal forces. This stability is achieved by slightly elongating the sphere along the spin axis to create a prolate ellipsoid. The semi-major axis of the ellipsoid is the spin axis of the electron, and is calculated to be 1.20% longer than the semi-minor axis, which is the radius of the equator. Although the shape deviates slightly from a perfect sphere, the electric dipole moment is zero. In the author’s previously published document, the attributes of the internal components of the electron, such as charge and mass, were calculated and expressed as ratios to the classically measured values for the composite electron. It is interesting to note that all of these ratios are nearly the same as the inverse of the Fine Structure Constant, with differences of less than 15%. The electron model assumed that the outer surface charge was fixed and uniform. By allowing the charge to be mobile and the shape to have a particular ellipticity, it is shown that the calculated charge and mass ratios for the model can be exactly equal to the Fine Structure Constant and the Constant plus one. The electron radius predicted by the model is 15% greater than the Classical Electron Radius.

A Flux Ratio Independent of the Permanent Charge in PNP Models

PNP models with an arbitrary number of positively charged ion species and one negatively charged ion species are studied in this paper under the assumption that positively charged ion species have the same valence and the permanent charge is a piecewise constant function. The permanent charge plays the key role in many functions of an ion channel, such as selectivity and gating. In this paper, using the geometric singular perturbation theory, a flux ratio independent of the permanent charge is proved.

Decouple charge transfer reactions in the Li-ion battery

In the development of Li-ion batteries(LIBs)with high energy/power density,long cycle-life,fast charging,and high safety,an insight into charge transfer reactions is required.Although electrochemical impedance spectroscopy(EIS)is regarded as a powerful diagnosis tool,it is not a direct but an indirect measurement.With respect to this,some critical questions need to be answered:(i)why EIS can reflect the kinetics of charge transfer reactions;(ii)what the inherent logical relationship between impedance models under different physical scenes is;(iii)how charge transfer reactions compete with each other at multiple scales.This work aims at answering these questions via developing a theory framework so as to mitigate the blindness and uncertainty in unveiling charge transfer reactions in LIBs.To systematically answer the above questions,this article is organized into a three-in-one(review,tutorial,and research)type and the following contributions are made:(i)a brief review is given for impedance model development of the LIBs over the past half century;(ii)an open source code toolbox is developed based on the unified impedance model;(iii)the competive mechanisms of charge transfer reactions are unveiled based on the developed EIS-Toolbox@LIB.This work not only clarifies theoretical fundamentals,but also provides an easy-to-use open source code for EIS-Toolbox@LIB to optimize fast charge/discharge,mitigate cycle aging,and improve energy/power density.

Review on charging model of sand particles due to collisions

In this paper, the models describing the charge transfer between two sand particles due to collisions are reviewed. By comparing the experimental results and the calculated results by the models carried on an individual particle due to a single collision, it indicates the Mosaic model is more reasonable to describe the collision charging mechanism. The Mosaic model cannot only describe the dependence of the collision charges on the relative collision speed and the particle size, but also reveal the relationship between the collision charges with the environmental temperature, the relative humidity and the material parameters, e.g., the absorption energy. Based on the Mosaic model, the model to describe the charges transfer due to multiple collisions is also developed, which can be used to calculate the charges carried by sand particles due to multiple collisions in the wind blown sand flux.

An Optimization Model of EVs Charging and Discharging for Power System Demand Leveling

This paper presents an advanced methodology for optimizing a UK network load demand with various uncertainties which are related to individual driving behaviours. Without the optimized regulation for traditional power system demand, EVs （electric vehicles） would have an adverse impact on the stability of power systems. This becomes more significant for large-scale EVs plugging into the power grid. Traditional optimized methodologies are effective only for EV charging. The proposed techniques improve the system flexibility and stability through an advanced optimization model and flexible bidirectional charging/discharging control. Three scenarios with different charging and discharging power levels and various penetration levels of EVs are discussed in detail in this paper. Simulation results demonstrate that bidirectional EV power flow control has vast potentials to improve the load demand profile, with increased proportion of EVs, and charging/discharging power levels.

Mathematical Wave Functions and 3D Finite Element Modelling of the Electron and Positron

The wave/particle duality of particles in Physics is well known. Particles have properties that uniquely characterize them from one another, such as mass, charge and spin. Charged particles have associated Electric and Magnetic fields. Also, every moving particle has a De Broglie wavelength determined by its mass and velocity. This paper shows that all of these properties of a particle can be derived from a single wave function equation for that particle. Wave functions for the Electron and the Positron are presented and principles are provided that can be used to calculate the wave functions of all the fundamental particles in Physics. Fundamental particles such as electrons and positrons are considered to be point particles in the Standard Model of Physics and are not considered to have a structure. This paper demonstrates that they do indeed have structure and that this structure extends into the space around the particle’s center (in fact, they have infinite extent), but with rapidly diminishing energy density with the distance from that center. The particles are formed from Electromagnetic standing waves, which are stable solutions to the Schrödinger and Classical wave equations. This stable structure therefore accounts for both the wave and particle nature of these particles. In fact, all of their properties such as mass, spin and electric charge, can be accounted for from this structure. These particle properties appear to originate from a single point at the center of the wave function structure, in the same sort of way that the Shell theorem of gravity causes the gravity of a body to appear to all originate from a central point. This paper represents the first two fully characterized fundamental particles, with a complete description of their structure and properties, built up from the underlying Electromagnetic waves that comprise these and all fundamental particles.

Extended Holstein polaron model for charge transfer in dry DNA

The variational method is applied to the study of charge transfer in dry DNA by using an extended Holstein small polaron model in two cases： the site-dependent flnite-chain discrete case and the site-independent continuous one. The treatments in the two cases are proven to be consistent in theory and calculation. Discrete and continuous treatments of Holstein model both can yield a nonlinear equation to describe the charge migration in an actual long-range DNA chain. Our theoretical results of binding energy Eb, probability amplitude of charge carrier Ф and the relation between energy and charge-lattice coupling strength are in accordance with the available experimental results and recent theoretical calculations.

Oil charging history and pathways of the Ordovician carbonate reservoir in the Tuoputai region,Tarim Basin,NW China

Geochemical analysis of 64 oils sampled from an Ordovician carbonate reservoir in the Tuoputai region was undertaken to study the composition of molecular markers. All the oils have similar geochemical characteristics and belong to a single oil family. They are presumed to derive from the same source kitchen and have similar oil charging history. A histogram of homogenization temperatures(Th) of aqueous inclusions in reservoir rocks shows a bimodal distribution pattern, indicating that the Ordovician reservoir has been charged twice. Coupling the measured Th(°C) with the burial and geothermal histories reconstructed using 1D basin modeling, we relate the homogenization temperature to the relevant geological ages: i.e.,425–412 and 9–4 Ma, corresponding to the Middle to Late Silurian and the Miocene to Pliocene, respectively. The oil filling orientation and pathways are traced using molecular indicators related to alkyldibenzothiophenes and benzo[b]naphthothiophenes. The oil charging orientation is from south to north generally. It can be predicted that the Ordovician reservoirs were sourced from a kitchen located to the south of the Tuoputai region, most probably between the Awati and Manjiaer Depressions. Traps located in the southern side of the Tuoputai region, along the oil charging pathways, should therefore be preferred oil exploration targets.

Review of optimized layout of electric vehicle charging infrastructures

Electric vehicle is a kind of new energy vehicle which uses batteries as energy supply unit.A huge gap in charging infrastructures will be created by the expansion of electric vehicles.The effectiveness and rationality of charging facilities will directly affect the convenience and economy of the users,as well as the safe operation of the power grid.Three types of charging facilities:charging pile,charging station and battery swap station are introduced in this paper.According to the different methods of charging infrastructure planning,the research status of the method of determining charging demand points is expounded.And the spatial distribution of charging demand points extracted by the current site selection method has a certain deviation.Then the models and algorithms of charging infrastructure optimized layout are reviewed.Currently,many researches focus on three categories optimization objectives:benefit of power company side,investment cost of charging facility and user side cost,and the genetic algorithm and particle swarm optimization are the main solving algorithms.Finally,the relative methods and development trend of the charging infrastructures optimized layout are summarized,and some suggestions on the optimized layout of electric vehicle charging infrastructures are given forward.

Load Cluster Characteristic and Modeling of EV Charge Station in Residential District

电动汽车的大规模发展将会对配电网带来较大影响,开展电动汽车充电的负荷特性研究是保证电网安全运行的前提,是引导电动汽车进行有序充电的基础。在简化锂电池恒流–恒压2阶段充电模型的基础上,得到单个电动汽车的充电模型,以此为基本元素,从充电汽车电池的初始荷电状态（initial state-of-charge,SOC0）和车辆到达充电站时间的随机分布为出发点,提出2阶段泊松分布的电动汽车充电站集聚模型进行充电站集聚特性的模拟,并提出基于充电站的日充电负荷曲线的电动汽车充电站负荷集聚模型的建模方法,最后通过仿真算例验证了其有效性。

Co-Estimation of State of Charge and Capacity for Lithium-Ion Batteries with Multi-Stage Model Fusion Method

Lithium-ion batteries(LIBs)have emerged as the preferred energy storage systems for various types of electric transports,including electric vehicles,electric boats,electric trains,and electric airplanes.The energy management of LIBs in electric transports for all-climate and long-life operation requires the accurate estimation of state of charge(SOC)and capacity in real-time.This study proposes a multistage model fusion algorithm to co-estimate SOC and capacity.Firstly,based on the assumption of a normal distribution,the mean and variance of the residual error from the model at different ageing levels are used to calculate the weight for the establishment of a fusion model with stable parameters.Secondly,a differential error gain with forward-looking ability is introduced into a proportional–integral observer(PIO)to accelerate convergence speed.Thirdly,a fusion algorithm is developed by combining a multistage model and proportional–integral–differential observer(PIDO)to co-estimate SOC and capacity under a complex application environment.Fourthly,the convergence and anti-noise performance of the fusion algorithm are discussed.Finally,the hardware-in-the-loop platform is set up to verify the performance of the fusion algorithm.The validation results of different aged LIBs over a wide range of temperature show that the presented fusion algorithm can realize a high-accuracy estimation of SOC and capacity with the relative errors within 2%and 3.3%,respectively.