207 results about "Ohmic Resistance" patented technology

The invention discloses a method for testing polarization and decoupling of a flow battery. The method aims to quantify and separate three phenomena of ohmic polarization, activation polarization and concentration polarization in the flow battery. Comprising the following steps: firstly, carrying out electrochemical impedance spectroscopy testing under open-circuit voltage and different working currents respectively to obtain ohmic resistance and charge transfer resistance, and carrying out integral calculation to obtain ohmic polarization and activated polarization; then, carrying out a step type constant current charging test to obtain a total polarization curve; and finally, subtracting the ohmic polarization and the activation polarization from the total polarization to obtain concentration polarization. The method is simple and convenient to operate and suitable for various types of flow batteries, a novel and effective solution is provided for polarization analysis of the flow batteries, an accurate test basis can be provided for optimization of battery design, and improvement of performance optimization and research level of the flow batteries is facilitated.

The invention discloses a sodium ion battery SOC estimation method based on extended Kalman filtering. The method comprises the following steps: acquiring charging and discharging voltage, current and open-circuit voltage OCV data of a sodium battery through an HPPC test and a capacity test; and fitting a function relationship between the OCV and the SOC based on the standing balanced voltage data. And constructing a three-order RC equivalent circuit model, and identifying ohmic resistance, polarization resistance and polarization capacitance parameters in the model through curve fitting. Based on the model, a state vector containing SOC and polarization voltage is defined, and a nonlinear state equation and a terminal voltage observation equation are established. And predicting the state vector and the covariance matrix at the current moment according to the state vector and the covariance matrix at the previous moment by using an extended Kalman filtering algorithm, calculating Kalman gain by combining the actually measured terminal voltage, correcting the prediction result, and updating the SOC estimation value. And through loop iteration, real-time high-precision dynamic estimation of the SOC of the sodium-ion battery is realized. The method provides an efficient and accurate SOC estimation solution for a sodium ion battery management system.

The present application provides a battery cell, a battery, and an electrical device, belonging to the field of battery technology. The battery cell includes a positive electrode sheet and an electrolyte solution. A coating mass of a positive electrode active material layer on a single side of the positive electrode sheet is 410 mg / 1540.25 mm2 to 550 mg / 1540.25 mm2, and a membrane resistance of the positive electrode sheet is ≥1Ω. A conductivity of the electrolyte solution is ≤14 mS / cm. The battery cell has thick coated electrode sheets, where the lower membrane resistance of the positive electrode sheet indicates its higher conductivity, which is conducive to reducing solid-state ohmic resistance of the battery cell. The higher conductivity of the electrolyte solution is conducive to reducing liquid-phase ohmic impedance of the battery and alleviating concentration polarization to some extent.

The invention discloses an SOC prediction method and system for a lithium ion battery of an electric forklift. The method comprises the steps that real-time data in the discharging process of the lithium ion battery are acquired; analyzing a real-time data change rule, and constructing a characteristic parameter model; a second-order RC equivalent circuit model is constructed, the model comprises a voltage source, an ohmic resistor and a second-order RC network, and the second-order RC network is used for describing the polarization effect of the charging and discharging stage; obtaining parameter identification results of the dynamic driving working conditions at different temperatures based on an ant colony algorithm; memory historical feature extraction of the time series data is realized based on a TCN model, including expansion convolution, causal convolution and residual connection; and selecting an average absolute percentage error and a mean square error as evaluation indexes. According to the method, parameter identification results of dynamic driving working conditions at different temperatures are obtained through the ant colony algorithm, the parameter identification results are input into the TCN model through corresponding transformation, and finally SOC estimation with high precision and robustness is achieved in LiFePO4.

A sodium ion battery parameter identification method based on a third-order equivalent circuit model comprises the following steps: applying pulse current to a sodium ion battery to carry out charge and discharge test, and collecting terminal voltage, current and capacity data in discharge and shelving stages; constructing a three-order equivalent circuit model formed by connecting three groups of RC parallel modules and ohmic resistors in series, and establishing a terminal voltage dynamic equation; ohmic resistance is calculated by using voltage break variables at the beginning and the end of a discharge pulse, a polarization process is divided into a zero-state response stage and a zero-input response stage, and polarization voltage nonlinear dynamic equations of all RC modules are deduced respectively. Based on an LM algorithm, a terminal voltage nonlinear function is constructed, polarization resistance and capacitance parameters are iteratively optimized, the error sum of squares of model output and actual data is minimized, and finally high-precision parameter identification is achieved. According to the method, the performance prediction precision of the sodium battery is improved, and reliable data support is provided for related applications.

An ohmic resistance estimation unit estimates an ohmic resistance value of each cell or each parallel cell block, based on the voltage data and the current data for each cell or each parallel cell block of a battery pack. A statistical calculation unit statistically processes the ohmic resistance value of each cell or each parallel cell block and calculates a representative value of the ohmic resistance value of a single cell or a single parallel cell block of a particular battery pack or of a plurality of battery packs of the same type. A correction value generation unit generates an external resistance correction value for correcting deviation of an external resistance of each cell or each parallel cell block, based on a difference between the ohmic resistance value of each cell or each parallel cell block and the representative value of the ohmic resistance value.

The invention discloses a battery pack equalization control method and system based on multidimensional state mapping, and the method comprises the steps: obtaining terminal voltage data, working current data and surface temperature data of each single battery in a target battery pack; calculating an ohm internal resistance value and a polarization impedance value of each single battery; calculating an impedance growth rate; according to the impedance growth rate and the surface temperature data, a health state value is determined, and an aging weighting coefficient is determined; determining a polarization safety coefficient of each single battery based on the polarization impedance value; calculating a state-of-charge value of each single battery in the target battery pack, and determining a balance demand deviation degree; determining a basic equalization duty ratio of each single battery according to the equalization demand deviation degree; correcting the basic balance duty ratio to generate a target pulse width modulation duty ratio; and according to the target pulse width modulation duty ratio, controlling equalization circuits connected to the two ends of each single battery to be switched on. The battery pack equalization control efficiency is improved.

The invention relates to the technical field of MOS (Metal Oxide Semiconductor) semiconductors, and discloses a SiC VDMOSFET (Vertical Double-diffused Metal Oxide Semiconductor Field Effect Transistor) structure with high heat dissipation performance, which comprises a plurality of MOS cells arranged in parallel, and is characterized in that each MOS cell comprises a metal drain electrode, a semiconductor epitaxial layer, a metal source electrode and a gate oxide layer covering the surface of the metal source electrode, performing ion implantation in the semiconductor epitaxial layer to form an N substrate layer, an N drift layer, an N well layer, a heavily doped P layer and a P well layer; source electrode doping layers are arranged on the two sides of a single MOS cell, the source electrode doping layers are in ohmic contact with the metal source electrodes, and the source electrode doping layers are made of gallium arsenide or gallium nitride or nichrome. According to the invention, the source electrode doping layer with the sinking design is arranged above the MOS cell, so that the N well layer can be in direct contact with the metal source electrode, and the N well layer can be in indirect contact with the metal source electrode through the source electrode doping layer, thereby reducing the ohmic resistance of the N well layer and the metal source electrode, and reducing the heating at the contact position.

A battery diagnostic device according to an embodiment of the present disclosure includes: a measuring unit configured to measure a voltage and a temperature of a battery; an ohmic resistance determining unit configured to determine the ohmic resistance of the battery based on an impedance curve generated for the battery; and a control unit configured to calculate a voltage change by comparing the voltage of the battery measured by the measuring unit with a reference voltage, calculate a resistance change rate by comparing the ohmic resistance determined by the ohmic resistance determining unit with a reference resistance, determine a degree of internal gas generation in the battery by comparing the calculated resistance change rate with a reference resistance change rate, and determine a cause of internal gas generation in the battery by comparing the calculated voltage change with a standard voltage change.

The invention discloses a low-temperature exposed lithium battery aging damage diagnosis method based on electrochemical nondestructive characterization, which comprises the following steps: firstly, acquiring electrochemical response data of a to-be-tested battery through electrochemical impedance spectroscopy (EIS) test and incremental capacity analysis (ICA); secondly, key characteristic parameters capable of representing ohmic internal resistance, charge transfer resistance and electric double-layer capacitance of the battery and phase change peak position, peak area, half-peak width and the like are extracted; and then, training a joint prediction model based on machine learning by using the extracted multi-dimensional features to judge whether the to-be-detected battery is subjected to over-low-temperature exposure or not and judge the current aging damage degree of the to-be-detected battery. According to the method, unique aging paths introduced by normal aging and low-temperature exposure can be effectively distinguished through a nondestructive testing means, accurate'traceability 'of historical damage of the battery and quantitative evaluation of the current state are achieved, and reliable technical support is provided for intelligent decision making of a battery management system (BMS), battery safety early warning and echelon utilization.

The utility model discloses a miniature ozone electrode module structure, relates to the technical field of miniature ozone generation, and is used for solving the problems of complex structure, large volume and low ozone generation efficiency of an ozone generator at the present stage. According to the utility model, the polar plates directly act in an aqueous solution through the ozone electrode module with a direct insertion shell structure, generated ozone does not directly act in the shell, the overall service life is prolonged, and meanwhile, a two-cathode and one-anode clamping type polar plate structure is adopted, so that the distance between the polar plates is controlled, and bubbles generated between the polar plates are effectively separated; meanwhile, the reaction spacing can be reduced as much as possible, the ohmic resistance of the reaction is reduced, reactants can be provided for the electrode reaction in time, the electrolytic mass transfer efficiency is also improved, the electric field distribution around the anode is more uniform, and meanwhile, the equipment is miniaturized and integrated, so that the production efficiency is improved. The method is suitable for application scenes with high requirements for space and cost.

The invention provides an aerosol generating device and a control method thereof. The aerosol generating device comprises a power supply circuit; the DC / AC inverter comprises an E-type power amplifier, and the E-type power amplifier comprises a transistor switch and an LC load network formed by a capacitor and an inductor; an inductor inductively coupled to the susceptor, thereby heating the aerosol-forming substrate to generate an aerosol; a controller configured to, in operation, determine an apparent ohmic resistance based on the DC supply voltage and a DC current output to the DC / AC inverter by the power supply circuit; the controller is further configured to monitor a change in the apparent ohmic resistance and adjust a frequency and a duty cycle of a switching signal supplied to the transistor switch when the apparent ohmic resistance changes. According to the aerosol generating device and the control method thereof, the frequency and the duty ratio of the switching signal supplied to the transistor switch are adjusted by monitoring the change of the apparent ohmic resistance and when the apparent ohmic resistance changes; therefore, the E-type power amplifier always works in the optimal state.

The invention relates to the technical field of bridge health monitoring, in particular to a bridge support corrosion current field imaging monitoring method and system, and the method comprises the steps: presetting a matrix type electrochemical sensor on a support steel plate, and collecting the inductance data of a collector at a sampling frequency of 0.1-0.5 Hz; ohmic resistance drift caused by temperature is eliminated through adaptive quantum Kalman filtering, and a resistance-current density distribution diagram is constructed; constructing a current density distribution diagram of the cross section of the support by adopting a back propagation electrical impedance tomography technology; when the corrosion rate exceeds 0.15 mm / year, an early warning system is triggered, the bearing capacity attenuation rate of the support is calculated, and the support is guided to be replaced; a topological separation technology of a multi-dimensional state space and quantum heuristic adaptive parameter optimization effectively eliminate temperature interference; through current field topology reconstruction and multi-source data fusion, the imaging precision is improved; the quantitative relation between the corrosion rate and bearing capacity attenuation of the support is established, and a scientific basis is provided for bridge maintenance.

The invention discloses a composite solid positive electrode, a battery cell, a single battery and electric equipment. The positive electrode is composed of a current collector, a positive active material, an electronic conductive agent, a solid electrolyte and an interface modifier. Wherein the positive active material is used for providing a lithium source; the electronic conductive agent is used for reducing ohmic internal resistance and polarization; the solid electrolyte is used for transmitting ions, and the interface modifier is used for further reducing internal resistance and polarization. When the solid electrolyte is a composite electrolyte of sulfide and a polymer, the infiltration problem of a solid-solid interface and the deformation problem caused by charging and discharging can be solved due to the existence of the interface modifier. The positive electrode material can be applied to battery systems such as liquid, solid and alkali metal batteries.

The invention relates to a gas diffusion layer and a preparation method thereof, a membrane electrode assembly, an alkaline electrolytic cell and water electrolysis hydrogen production equipment. The gas diffusion layer comprises a hydrophobic substrate layer and a microporous layer arranged on at least one surface of the hydrophobic substrate layer, and the microporous layer comprises a conductive material and an anion ionomer. By arranging the microporous layer containing the conductive material and the anion ionomer on at least one surface of the hydrophobic substrate layer, the resistivity of the diffusion gas layer is low, and the ohmic resistance can be effectively reduced. When the gas diffusion layer is used in the alkaline electrolytic cell, the transmission capability and the electron conduction capability of OH <-> in electrolyte can be effectively improved, the mass transfer and transportation loss is reduced, and the voltage of the alkaline electrolytic cell is effectively reduced, so that the operation power of the alkaline electrolytic cell is effectively reduced.

The invention provides a battery state estimation method and system and a medium, and relates to the technical field of a battery management system.The method comprises the steps that a second-order RC equivalent circuit model is established, and parameters such as ohm internal resistance, polarization internal resistance and polarization capacitance are identified online through an RLS with a forgetting factor; constructing a microscopic state SRCKF channel and a macroscopic parameter SRCKF channel, performing real-time correction on an SOC influence factor and a current influence factor based on a filtering performance index, adaptively adjusting process noise and measurement noise covariance according to sub-channel logic, and introducing cross-channel cooperative self-adaption; the state channel outputs SOC and terminal voltage estimated values, the parameter channel outputs dynamic internal resistance and maximum available capacity, and SOH is calculated and output. The method improves the estimation precision and robustness under the working conditions of low SOC and large current, has good numerical stability, and is suitable for monitoring the whole life cycle of the power battery.

Two methods for determining the lubricant film thickness based on measuring the capacitance of a bearing arrangement and the ohmic resistance are disclosed. A special feature is that in order to determine the lubricating film thickness on the basis of the electrical relationships between capacitance and distance between two plates as well as resistance and conductor length, an effective area is assumed as the plate area or conductor cross-section, which is determined based on at least one other operating condition in addition to the load acting on the bearing.

A dry electrode according to the present invention exhibits uniform distribution of a binder resin and / or an electrode active material in the thickness direction of an electrode active material layer, and thus exhibits excellent adhesion between the electrode active material layer and a current collector and improves the shape stability of the electrode active material layer. In addition, in the electrode active material layer of the dry electrode, the electrode active material does not have uniform alignment but has irregular alignment. A secondary battery, according to the present invention, comprising the dry electrode has an ohmic resistance that decreases according to a change in the state of charge (SOC), so as to have low heat generation if a high current such as high-speed charging is applied, and thus exhibits high battery driving safety and is advantageous with respect to thermal management of a battery.

The present invention discloses a method for measuring the resistance of a battery electrode sheet and a battery, the method comprising: obtaining two slices of the same area size of the battery electrode sheet to be tested, assembling the two slices into a symmetrical battery, and determining the electrochemical AC impedance spectrum of the symmetrical battery; determining the electronic resistance value and the ionic resistance value of each slice of the battery electrode sheet to be tested based on the electrochemical AC impedance spectrum; determining the ohmic resistance value R of each slice of the battery electrode sheet to be tested based on the electronic resistance value and the ionic resistance value. Ω0 ; Determine the area A0 of each slice of the battery electrode to be tested and the area A1 of the battery electrode to be tested; Based on the area A0 of each slice of the battery electrode to be tested and the ohmic resistance value R Ω0 , and the area A1 of the battery electrode to be tested, determine the ohmic resistance value R of the battery electrode to be tested Ω1 The present invention can simplify the test method of the battery electrode sheet resistance, reduce material cost and test time, and simplify data processing.

Instrumented nut, clamping sleeve, clamping device and method for tightening such a nut. The invention relates to an instrumented metal nut (10b) comprising a tubular body having a polygonal drive surface (14). The nut comprises, on at least one annular portion (34) of its outer surface: an electrically insulating layer (36) applied to the annular portion; a piezoresistive conductive polymer (38) whose ohmic resistance varies according to a stress exerted during tightening of the nut on a threaded fastener, said conductive polymer being applied to the electrically insulating layer; and at least two electrodes (40). Figure for the abstract: Figure 2

The application provides a power battery thermal runaway diagnosis method and system based on a hybrid prediction framework, sample data at time t of the battery is collected, and the sample data is preprocessed; a first-order equivalent circuit model of the power battery is constructed, and the least square method is used to identify the voltage, ohmic resistance, polarization resistance and polarization capacitance in the initial state; a SOC estimation model is constructed by using a current integration method; a battery internal temperature estimation model is constructed based on the internal Joule heat of the power battery and the heat exchange heat of the external environment; the standardized data in step S2 are input into a recurrent neural network GRU for training to obtain estimated sample data at time t+1; state space models are respectively constructed based on the SOC estimation model and the battery internal temperature estimation model; the estimated sample data is input into an adaptive unscented Kalman filter AUKF model as observation at time t+1 based on the state space models, and prediction data at time t+1 is calculated; and the thermal runaway is predicted through the prediction data.

The application discloses a composite electrolyte buffer layer for solid oxide electrolysis cell and a preparation method, and relates to the technical field of SOFC electrolyte. The composite electrolyte buffer layer is formed by sequentially sputtering electrolyte sputtering dense layer I, electrolyte sputtering dense layer II and anode sputtering layer on the surface of the electrolyte layer of the solid oxide electrolysis cell. The thickness of the electrolyte sputtering dense layer I is 10 nanometers to 1 micrometer, the thickness of the electrolyte sputtering dense layer II is 50 nanometers to 500 nanometers, and the thickness of the anode sputtering layer is 5 nanometers to 30 nanometers. The composite electrolyte nanometer buffer layer prepared by the magnetron sputtering method has the advantages of blocking electrons, improving open circuit voltage, enhancing ion conductivity to reduce ohmic resistance, enhancing chemical compatibility and thermal matching with electrodes to improve long-term stability, etc. The composite electrolyte nanometer buffer layer solves the problem of internal leakage of the traditional low-temperature electrolyte, improves the open circuit voltage to above 1.00V (600 DEG C), improves the output power and stability of the solid oxide electrolysis cell, and expands the application range of the solid oxide electrolysis cell.

The application discloses a kind of lithium battery's residual life prediction method, belong to battery life prediction technical field.The application first divides lithium battery charging process into constant-current section, transition section and constant-voltage section, collects voltage and current signal in each section, obtains equivalent transient impedance spectrum by Fourier transform, and calculates interface aging factor based on charge transfer resistance, ohmic resistance and double-layer capacitance;Then respectively extract the features in each section to form the feature vector in each section, derive to obtain the feature vector between sections, splice the three feature vectors in each section corresponding to similar data and two feature vectors between sections to form feature splicing vector;Finally, using the feature weighted distribution type BP model, the feature splicing vector of equivalent transient impedance spectrum and interface aging factor is processed, and the residual life prediction value is output.The application improves the prediction accuracy significantly by charging segmented feature extraction, inter-feature extraction and weighted model optimization.

An apparatus and method for generating an electrical circuit of semiconductor channel resistor including a first passive element part including a resistor and a capacitor connected in parallel between a first port and a second port, and an ohmic resistor connected in series to the resistor and the capacitor which are connected in parallel are provided. The apparatus includes a substrate selection part configured to receive a selected substrate item; a resistor selection part configured to receive a selected resistor item; a capacitor selection part configured to receive a selected capacitor item; and a circuit generating part configured to generate an electrical circuit from the selected substrate item, the selected resistor item, and the selected capacitor item.

The application provides an energy flow modeling analysis method of an alkaline water electrolysis hydrogen production system, which comprises the following steps: for the stack component, based on an electrochemical reaction mechanism equation and an Ohm's law, defining a reversible voltage and an activation overvoltage as a voltage source in an electrolysis cell unit, defining an Ohm's resistance according to an Ohm's overvoltage, connecting different circuit elements to obtain an electrochemical energy flow model of the stack; establishing a heat transfer energy flow model of a gas-liquid separator, the stack component, a mixer and a heat exchanger, connecting nodes with the same temperature, and establishing a system overall heat transfer energy flow model; taking an ambient temperature and a cold fluid inlet temperature as boundary conditions, and according to the electrochemical energy flow model of the stack component, the system overall heat transfer energy flow model and corresponding constraint conditions, combining system operation parameters and system structure parameters to solve the model, and obtaining an alkaline water electrolysis hydrogen production system operation analysis result. The energy flow modeling analysis method of the alkaline water electrolysis hydrogen production system provided by the application realizes the cross-scale unified modeling and analysis of the alkaline water electrolysis hydrogen production system by establishing the heat transfer energy flow model of the external system and the electrochemical energy flow model of the internal process of the stack.

The application discloses a kind of intelligent determination method and device of battery charging demand current, the method includes: based on the historical open-circuit voltage parameter of pre-set battery and historical ohmic resistance parameter, determine the current open-circuit voltage parameter of battery and current ohmic resistance parameter;Based on current open-circuit voltage parameter and current ohmic resistance parameter, calculate the current charging current limit of battery;Based on current charging current limit, determine the current charging demand current of battery. Visible, the charging current limit of battery can be calculated in real time by implementing the application, to evaluate the charging limit capacity of battery, and determine the charging demand current of battery, so that the reliability and accuracy of the charging demand current determined can be improved, and then the vehicle battery can be reliably and accurately charged, so that the charging safety and charging efficiency of vehicle battery can be improved, to realize the good charging effect of vehicle battery.

The invention relates to a method for de-exciting a rotor winding of a rotor of an electric machine (2) of a motor vehicle (1), the electric machine comprising a stator and a rotor mounted rotatably relative to the stator, the rotor having a rotor winding for generating a rotor magnetic field, an active rectifier being arranged on the rotor side, the rectifier comprises at least one field effect transistor which can be actuated by means of an actuation voltage, the rectifier electrically connects a voltage source present on the rotor side to the rotor winding, by means of which an alternating voltage provided by the voltage source can be converted into a direct voltage, the field effect transistor or at least one of the field effect transistors is brought into an operating state, in which the respective field effect transistor forms an ohmic resistance, by means of a control voltage, and the energy stored in the rotor winding causes a current to flow through the at least one field effect transistor forming the ohmic resistance, at least a portion of the energy is converted into thermal energy.

The utility model relates to the technical field of large current control, in particular to a control circuit for balancing multipath load output, which comprises a low-dropout linear voltage regulator U4, a low-dropout linear voltage regulator U9, a low-dropout linear voltage regulator U10, resistors R85, R86, R87, R88, R89, R90, R91 and R92, ohmic resistors R93 and R94, sampling resistors R133 and R134, current limiting resistors R135, R136 and R137, output filter capacitors C32, C56, C57, CE2, C33, C34, C35, C30, C31, C60, C28 and C29, input filter capacitors C58, C59, C61, C62 and C63, output filter capacitors C32, C56, C57, CE3, C33, when the whole system of the control circuit for balancing multi-path load output works, the output of each path of small power supply is circularly controlled through the general control end to achieve parallel output of large current, a single path of power supply is controlled not to be overloaded, and the output of each path of power supply is balanced.

A battery diagnostic device according to one embodiment of the present invention includes: a measuring unit, which is used to measure the discharge capacity and temperature of a battery; an ohmic resistance determining unit, which is used to determine the ohmic resistance of the battery based on an impedance curve generated relative to the battery; and a control unit, which calculates a capacity change rate by comparing the discharge capacity of the battery measured by the measuring unit with a reference capacity, calculates a resistance change rate by comparing the ohmic resistance determined by the ohmic resistance determining unit with a reference resistance, determines an amount of internal gas generation of the battery by comparing the calculated resistance change rate with a standard resistance change rate, and determines a cause of internal gas generation of the battery by comparing the calculated capacity change rate with a standard capacity change rate.

The invention relates to the field of batteries, in particular to an electrolyte and a battery. According to the electrolyte, a solvent formula with a specific proportion is mixed with an additive for use, the additive forms a solid electrolyte interface film on the surface of an electrode prior to the solvent in a battery activation stage, and the first additive can be in contact with trace water in the electrolyte preferentially, so that the content of HF in a circulation process is reduced; meanwhile, other additives can be matched to form a stable CEI film rich in inorganic components on the surface of an electrode, so that the side reaction on the surface of the electrode is reduced, the cycle life of the battery is prolonged, meanwhile, due to the addition of the low-viscosity solvent, the ionic conductivity in the electrolyte is improved, the ohmic resistance of the battery is reduced, and the service life of the battery is prolonged due to the uniformity of the CEI film. And due to low interface impedance, the electrolyte can meet the working condition under high magnification.