205 results about "Current density distribution" patented technology

The invention relates to the technical field of online calibration, in particular to a multi-parameter fusion intelligent electric energy meter online calibration method and system, and the method comprises the following steps: collecting voltage waveforms, current harmonics and active power data, dividing windows, calculating a covariance matrix, and generating a feature set; a power factor curvature extreme value and a temperature inflection point offset are analyzed to generate an interference identifier, current density distribution and a voltage distortion spectrum are jointly analyzed to extract a harmonic energy ratio to generate a feature vector, and phase compensation is performed on a pulse sequence to generate a calibration instruction set. According to the method, the covariance matrix is constructed by synchronously collecting voltage and current power parameters, the abnormal mark section is generated by combining the temperature change and the covariance difference value, the environment disturbance and the real deviation are effectively distinguished, and the temperature hysteresis effect is identified through the power factor curvature extreme value and the temperature inflection point offset. And combining current density and voltage distortion spectrum analysis to extract a fundamental wave and harmonic wave energy ratio, establishing a composite calibration reference, and dynamically adjusting a pulse duty ratio to realize harmonic wave energy compensation.

The invention discloses an operation state monitoring method and system for AEM water electrolysis hydrogen production equipment, particularly relates to the technical field of electrolytic bath operation monitoring control, and aims to solve the problem of efficiency nonlinear fluctuation caused by polarization mode alternating dominance and microstructure degradation under a low current density working condition in the prior art. Extracting polarization fluctuation characteristics by generating a dynamic response sequence and calculating a dynamic coupling degree to identify a polarization alternating dominant mode; analyzing a local blocking probability based on frequency characteristics, positioning an active site sparse region in combination with temperature gradient spatial distribution characteristics, and generating an efficiency fluctuation evaluation coefficient; an active site sparse region and a dynamic compensation factor matrix of a cathode flow field pressure gradient are constructed to cooperatively adjust an anode current density distribution weight and a cathode pressure gradient parameter, so that an adjusting variable is accurately matched with a local blocking probability and a dynamic coupling degree; the multi-scale correlation analysis of the microcosmic degradation state and the macroscopic efficiency fluctuation of the electrolytic cell is realized, and the operation stability under the low current density is remarkably improved.

The invention relates to the technical field of fault diagnosis of power electronic equipment, and particularly discloses a fault analysis and diagnosis method and system for a mining high-voltage frequency converter, and the method comprises the steps: collecting the skin effect depth and parasitic parameter drift distance in real time under a high-frequency working condition through a multi-physics field sensor array; constructing three-dimensional current density distribution of the conductor based on a non-Euclidean space mesh generation technology, and dynamically correcting the equivalent resistivity of the conductor in combination with a metamaterial database to calculate a dynamic eddy current loss characteristic value; optimizing and solving the parasitic parameter time-varying evolution equation by using a quantum annealing algorithm to obtain a voltage peak sensitivity characteristic value; inputting the characteristic value into a pre-trained deep residual shrinkage network diagnosis model for multi-modal fusion analysis, and outputting a fault risk assessment result; according to the method, the problem of parasitic parameter time-varying characteristic modeling in the vibration environment is innovatively solved, and early warning of hidden faults is achieved.

The invention discloses a PCB circuit microdefect real-time detection algorithm optimization method based on artificial intelligence, and relates to the field of printed circuit board monitoring, and the method comprises the steps: collecting multi-physical field data including a temperature field, a stress field, current density distribution and corrosion medium concentration in real time; generating time-space synchronous multi-modal fusion data; quantifying a thermal-mechanical-electric-chemical field interaction relationship through an inter-field coupling coefficient matrix; generating a four-dimensional synergistic effect matrix through tensor fusion; and based on the four-dimensional synergistic effect matrix, in combination with a spatio-temporal evolution diagram output by the carbonization path prediction model, establishing a three-dimensional mapping relationship among the crack size, the carbonization path and the material residual strength, and predicting a residual life prediction value. The method has the advantages that through real-time synchronous fusion of multi-physical field data and tensor coupling modeling, accurate tracking of a crack propagation path and dynamic evaluation of the residual life are achieved, the detection sensitivity is improved, and the life prediction error is reduced.

The invention discloses a continuous prebaked anode aluminum electrolysis production method and system, and relates to the technical field of anode aluminum electrolysis production, and the method comprises the following steps: firstly, collecting current density distribution data and electrolyte distribution state in an electrolytic cell through a real-time monitoring system, and reflecting current and electrolyte conditions of each area in the electrolytic cell in real time; and data support is provided for subsequent adjustment measures. The electrolyte distribution in the electrolytic cell is monitored in real time and intelligently evaluated, intelligent evaluation is performed in combination with the deep learning model, current distribution is automatically adjusted, and it is ensured that the current density is uniform. According to the scheme, the problems of local overload, excessive consumption of the anode and overheating of equipment are effectively avoided, the energy efficiency and the stability of the electrolysis process are improved, the service life of the equipment is prolonged, the maintenance cost is reduced, the downtime is shortened, and therefore the production efficiency and the economic benefits are improved. And meanwhile, human intervention is reduced, the automation level is improved, and the intelligent management capacity of aluminum electrolysis production is enhanced.

The invention provides an optimized winding method and system for a high-frequency transformer winding. A comprehensive parameter database based on current density distribution data of a high-frequency switching power supply is established, the axial temperature of a winding layer is collected in real time in combination with a self-calibration multi-axis winding device, and tension and interlayer gap compensation parameters are generated through temperature gradient feedback. The tension parameter drives the machine to adjust the winding tightness, and the gap parameter optimizes the heat dissipation channel. And synchronously fusing the current distortion data of the LLC resonant topology and an electromagnetic field simulation result, and generating a resonant frequency adjustment signal to suppress abnormal high-frequency current distribution. And dynamic matching of winding tightness, current distribution and heat dissipation requirements is realized through cooperative control. According to the system, electromagnetic, mechanical and thermal field multi-dimensional linkage is adopted, the skin effect and hot spot concentration are reduced, the temperature rise gradient is balanced, and the high-frequency working condition stability is enhanced. According to the technical scheme, through electromagnetic, mechanical and thermal field cooperative regulation and control, the temperature rise peak value of the high-frequency winding is greatly reduced, and the efficiency is greatly improved.

The invention relates to a waveguide grating, in particular to a method for manufacturing a waveguide grating with continuous gradually-changing groove depth, which comprises the following steps of: accurately measuring and calibrating ion beam current density distribution of a used ion beam in a working plane; establishing a cooperative control model associated with a target groove depth curve, ion beam current density distribution and scanning speed, associating the etching depth with the ion beam total dose, and accurately controlling the ion beam total dose received by each point on the waveguide grating by dynamically regulating and controlling the scanning speed of the substrate relative to the ion beam, so as to realize accurate control of the etching depth. The accurate control on the groove depth distribution is realized; based on the cooperative control model, the scanning speed corresponding to the target groove depth curve is solved by combining the set target groove depth curve and the calibrated ion beam current density distribution; and performing ion beam etching based on the solved scanning speed, and finally forming a continuous gradual change groove depth accurately corresponding to the target groove depth curve on the waveguide grating. The method can effectively overcome the defect that the high-precision waveguide grating with the continuous gradually-changing groove depth is difficult to manufacture.

The invention discloses an adjustable self-cleaning electric flocculation device, and relates to the technical field of electric flocculation devices, the adjustable self-cleaning electric flocculation device comprises an electric flocculation tank, a support plate is slidably connected to the electric flocculation tank, first polar plates are uniformly arranged in the electric flocculation tank, second polar plates are arranged in the support plate in a staggered manner, and the adjustable self-cleaning electric flocculation device also comprises a polar plate spacing adjusting mechanism, a self-oscillation mechanism and a self-cleaning mechanism; the polar plate distance adjusting mechanism is arranged at the bottom of the electric flocculation tank and is used for adjusting the distance between the first polar plate and the second polar plate; the self-oscillation mechanism is arranged above the first polar plate and is used for vibrating and removing impurities from the first polar plate; compared with the prior art in which polar plates are arranged at fixed intervals, the device can be accurately matched with wastewater with different electrical conductivity by dynamically adjusting the intervals of the electrodes, so that the current density distribution is more uniform. For example, the ineffective energy consumption can be reduced by increasing the electrode spacing of the low-conductivity wastewater, and the electric field intensity can be enhanced by reducing the spacing of the high-conductivity wastewater, the dissolution efficiency of metal ions can be improved, and the treatment period can be shortened to 30-60 minutes.

The invention relates to a physical field coupling simulation analysis method and device of a circuit breaker, computer equipment, a computer readable storage medium and a computer program product. The method comprises the following steps: acquiring distributed conductivity in an arc extinguish chamber of the circuit breaker; according to the distributed conductivity and an electric field finite element equation, an electric field distribution value in the circuit breaker arc extinguish chamber is obtained through calculation; calculating a current density distribution value in the arc extinguish chamber of the circuit breaker based on the electric field distribution value; substituting the current density distribution value into an axisymmetric magnetic field equation, and performing electric field and magnetic field coupling; substituting the port boundary voltage and the port current of the arcing area of the circuit breaker into the circuit matrix equation, and carrying out electric field and circuit bidirectional coupling; the electric field finite element equation, the axial symmetry magnetic field equation and the circuit matrix equation are combined, and the potential distribution value and the magnetic field distribution value of the arcing area of the circuit breaker and the port boundary voltage and the port current of the equivalent resistor are obtained through solving. By adopting the method, the simulation analysis efficiency and precision of the circuit breaker arc extinguish chamber can be improved.

The invention relates to a battery contact resistance in-plane distribution estimation method and device, computer equipment and a storage medium. The method comprises the following steps: operating a to-be-detected battery under a stable operation condition, and collecting current density distribution of each region in the to-be-detected battery; each region is obtained by dividing according to a cathode flow field structure and an anode flow field structure of the to-be-detected battery; when the state of the to-be-detected battery meets a preset state condition, ohmic impedance distribution identification is carried out according to the current density of each region, ohmic impedance of each region is determined, and the preset state condition is matched with the stable operation condition; and determining the contact resistance of each region according to the ohmic impedance of each region. And the membrane is completely hydrated through high-humidity and high-current stable operation of the battery, so that the membrane impedances in different areas in the surface are approximately equal. And the accuracy of identifying the contact resistance of the to-be-detected battery is improved.

The invention relates to the technical field of NV color centers, and discloses an NV color center magnetic field and current measurement method and system. The method comprises the following steps: performing decomposition and noise reduction on the two to generate target three-dimensional data, and constructing a joint response equation by combining the resonant frequency offset and the fluorescence intensity change value of the target three-dimensional data; and finally, decoupling the equation to obtain a global magnetic field estimation value, and determining a current density distribution diagram according to the value and the vacuum magnetic conductivity. According to the method, the initial signal quality is improved through the quantum coherence enhanced pulse sequence, the influence of interference such as environmental thermal noise on the magnetic field signal is effectively weakened through decomposition noise reduction and joint response equation decoupling, and the magnetic field characteristics are accurately extracted, so that high-precision data support is provided for subsequent magnetic field analysis and current density distribution determination. The technical problem that in the prior art, interference such as environmental thermal noise exists generally, so that initially-collected magnetic field signals are mixed with a large amount of noise, and follow-up magnetic field and current analysis is seriously affected is solved.

The invention relates to the technical field of battery simulation, in particular to a temperature adjustment method and system for simulating a battery based on a battery simulator. The method comprises the following steps: collecting the material thermal conductivity, thickness and layer number information of the battery cell lamination structure, and recording the information as battery cell lamination structure data; performing thermal resistance calculation on each layer of the battery cell according to the battery cell lamination structure data to obtain thermal resistance distribution data of each layer of the battery cell; performing space-time inversion simulation on the heat accumulation condition in the battery cell in the rapid charging process to obtain battery cell heat accumulation simulation data; and determining current density distribution data in the battery cell in the rapid charging process according to the thermal resistance distribution data of each layer of the battery cell and the battery cell heat accumulation simulation data. Through data monitoring technology data and data simulation technology, thermal resistance distribution calculation of heat accumulation in the battery cell is realized, accurate simulation of a heat accumulation path is realized, cooling efficiency is improved, and battery safety is enhanced.

The invention discloses an antenna performance analysis method and device for a mobile terminal, and relates to the technical field of communication, and the method comprises the steps: obtaining different antenna digital models and the working frequency corresponding to each antenna digital model; placing each antenna digital model at different positions of the mobile terminal shell model to obtain a plurality of mobile terminal models of each antenna digital model; according to various mobile terminal position association information, the mobile terminal model is combined with the head model and the hand model, and different simulation scenes are constructed; determining information such as current density distribution of the mobile terminal model in a free space, OTA performance and electromagnetic radiation in different simulation scenes by using an electromagnetic simulation algorithm; training the neural network model by using the simulation result to obtain an antenna performance analysis model; and performing antenna performance analysis by using the antenna performance analysis model. The antenna performance analysis cost of the mobile terminal can be reduced, and the analysis efficiency and the accuracy of the analysis result can be improved.

The invention discloses an electrophysiological signal fusion method and device, relates to the technical field of biomedicine, and mainly aims to solve the problem of low cardiac imaging evaluation accuracy caused by poor effectiveness of existing electrophysiological signal fusion. The method includes the steps that electrophysiological signals obtained after cardiac organs are collected and subjected to active magnetic field compensation and passive magnetic field compensation are obtained, and active magnetic field compensation signals of active magnetic field compensation are completed by controlling a main control magnetic field source based on a deep neural network model; a passive magnetic field compensation signal of the passive magnetic field compensation is completed based on residual magnetic field data modeling; screening effective signals from the electrophysiological signals, and performing inversion reconstruction on the effective signals to obtain current density distribution; cross-modal fusion is conducted on the electrophysiological signals, the current density distribution and the electrocardiosignals through a deep learning model after model training is completed, a signal fusion result is obtained, and the deep learning model is trained based on Maxwell constraints.

The invention relates to the technical field of semiconductor device design and simulation, in particular to a multi-physics-field coupled photoelectric detector modeling method and system, and the method comprises the steps: calculating the spatial distribution of the carrier generation rate, the carrier recombination rate, the potential, the distribution of electron concentration and hole concentration, and heat effect feedback data of a surface incidence semiconductor photoelectric detector; calculating the current density distribution of the target surface incident semiconductor photoelectric detector under the dynamic input optical power; based on an automatic differential Newton iteration method, a multi-physics field coupling equation set is solved according to spatial distribution of a carrier generation rate, current density distribution, a carrier recombination rate, potential, distribution of electron concentration and hole concentration and heat effect feedback data; and establishing an equivalent circuit model of the surface incidence semiconductor photoelectric detector, and carrying out co-simulation with an external circuit. Therefore, the problems of insufficient physical field coupling, poor numerical stability, low calculation efficiency, inaccurate simulation and the like in a traditional photoelectric detector simulation method are solved.

The invention relates to the technical field of thermoelectric material surface treatment, and provides a bismuth telluride-based thermoelectric material wafer surface treatment method which comprises the following steps: acquiring multi-dimensional data such as current density distribution, temperature field distribution, solution concentration gradient and plating thickness increment in real time through a sensor array; performing iterative calculation on the data based on a thermoelectric performance parameter optimization model to generate an optimal parameter combination of chemical oil removal, activation, nickel plating and tin and bismuth plating processes; dynamically adjusting the anode plate area ratio, the current density threshold value and the solution temperature fluctuation range of the electroplating equipment; a self-adaptive feedback mechanism is used for correcting parameter deviation, so that a uniform thermoelectric function layer structure is formed on the surface of the wafer. According to the method, the uniformity and the thermoelectric performance stability of the surface coating of the bismuth telluride thermoelectric wafer can be improved, the defect rate is reduced, and the production efficiency and the product consistency are improved.

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 relates to the technical field of medical rehabilitation equipment, in particular to pelvic floor muscle group electrical stimulation equipment with a customizable appearance and a customizing method thereof.The pelvic floor muscle group electrical stimulation equipment comprises a treatment probe with the customizable appearance, and the treatment probe comprises a center shaft, a balloon body wrapping the center shaft and at least one flexible tensioning belt; one end of the flexible tensioning belt is anchored to the inner wall of the balloon body, the other end of the flexible tensioning belt penetrates through the outer wall of the center shaft to be connected with a locking ring arranged in the center shaft, the length of the flexible tensioning belt is determined by the rotating angle of the locking ring, and the locking ring can rotate when heated and cannot rotate after being cooled. According to the embodiment of the invention, the shape of the treatment probe can permanently reproduce the physiological contour of a user through one-time shaping and curing, so that the adaptation problem of a standardized probe is fundamentally solved, the wearing comfort and stability are greatly improved, the close and uniform contact between an electrode and pelvic floor muscle tissue is ensured, and the treatment effect is improved. And the current density distribution is uniform.

The invention belongs to the field of bipolar plates, and particularly discloses a high-temperature solid oxide electrolytic cell bipolar plate based on an X-type cross flow field, which comprises a cathode plate body and an anode plate body, the cathode plate body comprises a cathode flow field plate used as a core support structure of the cathode plate body; the X-shaped cross runner flow field is arranged on the outer side of the cathode flow field plate; the X-shaped cross flow channel flow field comprises an X-shaped cross flow channel and a plurality of parallel first straight flow channels, and the X-shaped cross flow channel is arranged among the first straight flow channels and used for communicating the first straight flow channels; the cathode gas inlet is arranged at the inlet end of the cathode flow field plate; and the cathode gas outlet is arranged at the outlet end of the cathode flow field plate. Through the structural design of the X-shaped cross flow channel flow field, the gas and current density distribution uniformity is improved, the voltage drop and the power consumption are reduced, the generation of local hot spots and thermal stress is inhibited, the thermal management and operation performance of the electrolytic cell is remarkably improved, and the service life of the electrolytic cell is prolonged.

According to the parking battery energy distribution optimization method and system, the initial flowing direction of battery electrolyte is calculated by monitoring the three-axis acceleration and angular speed of a vehicle in real time, and electrolyte concentration gradient distribution is simulated and predicted in combination with fluid mechanics. And when the concentration gradient exceeds a threshold value, dynamically dividing an electrode area and optimizing an activation proportion, synchronously calculating current density distribution and an electrochemical reaction rate, and deducing the real-time output power of the battery by using an equivalent circuit model. By comparing real-time power requirements of electric equipment, a pulse width modulation technology is adopted to generate an initial energy distribution scheme, switching frequency distribution of an electrode activation area is finely adjusted based on current density requirements, and finally dynamic regulation and control of the battery management system on electric energy output are achieved. According to the method, the problem of output power fluctuation caused by non-uniform electrolyte distribution due to vehicle shaking in a parking state is effectively solved, and the energy distribution efficiency and the power supply stability of the battery with the special-shaped structure under a complex working condition are greatly improved.

The invention provides a pole group assembly and a lead-acid battery, and relates to the technical field of lead-acid batteries. The plate group assembly comprises a grid, a first busbar, a second busbar and a shell structure, tabs are fixed at the tops and the bottoms of the grids, the tabs at the tops of the grids are electrically connected through a first busbar, and the tabs at the bottoms of the grids are electrically connected through a second busbar; the plurality of grids are all mounted in the shell structure, mounting holes are formed in the side wall of the shell structure, the mounting holes extend to the bottom from the top of the shell structure, conductive parts are arranged in the mounting holes, and the first busbar and the second busbar are electrically connected through the conductive parts. According to the plate group assembly, the tabs are arranged at the top and the bottom of the grid, and the first busbar and the second busbar are electrically connected through the conductive piece, so that the potential difference between the top and the bottom of the grid can be reduced, the utilization rate of active substances in the middle and the bottom of the grid is improved, and the current density distribution on the grid is more uniform; and the cycle life of the battery is prolonged.

According to the method for locally plating the chromium on the metal surface of the part, the metal surface of the part comprises a surface B needing to be plated with the chromium and a surface A which is adjacent to the surface B and does not need to be plated with the chromium, and a groove is formed between the surface B and the surface A to separate the surface B and the surface A; before electroplating, a non-ferrous metal sheet is tightly bonded to the A face through insulation paste so that the A face can be shielded by the non-ferrous metal sheet, and insulation protection is conducted on the other non-plated faces needing to be protected through insulation protection materials; and the surface B is soaked in electroplating liquid, and electroplating treatment is conducted after electrification. According to the method, non-plating surface protection is achieved, the current density distribution condition of the chromium plating surface is improved, the obtained chromium plating surface is smooth and fine, and the edge is free of the wavy defect; compared with a traditional insulating material, the tool clamp is low in cost, easy and convenient to operate and high in manufacturing qualification rate.

The invention provides a heavy metal contaminated soil remediation effect evaluation method and system.The method comprises the steps that firstly, the heavy metal effective state content, microbial index data, plant index data and heavy metal ion migration data of a monitoring area are collected; calculating a repair efficiency index by using the first three types of data, exciting a nano-catalyst by microwave energy to generate active oxygen to catalyze the form transformation of the heavy metal, and recording temperature rise curve data in the reaction process; calculating a current density value of each monitoring point based on the ion migration data and generating a spatial distribution diagram; and fusing the remediation efficiency index, the temperature rise curve and the current density distribution data, inputting the fused data into a convolutional neural network, and finally outputting a soil remediation effect grade evaluation result and a spatial difference analysis result. According to the method, the accuracy and comprehensiveness of heavy metal contaminated soil remediation effect evaluation are improved.

The invention provides a metal pitting defect degree evaluation method and system based on artificial intelligence, and the method comprises the steps: obtaining microscopic porosity distribution data of a metal plate in a forming process, and an internal fluctuation signal of the metal plate under the action of a directional stress wave; based on the propagation attenuation rate of the internal fluctuation signal, generating geometric parameters of the structure abnormal area corresponding to the micro porosity distribution data; acquiring current density distribution data of the structure abnormal region; inputting the microscopic porosity distribution data, the geometric parameters of the structure abnormal region and the current density distribution data into an artificial intelligence model so as to associate the microscopic porosity distribution data with the current density distribution data, and generating a pore current coupling characteristic matrix of the metal plate; according to the pore current coupling characteristic matrix, generating a quantitative evaluation result of the internal pitting defect degree of the metal plate; according to the technical scheme provided by the invention, dynamic quantitative evaluation on the degree of the pitting corrosion defect in the metal is realized, and the technical bottleneck of a traditional single-index detection method in defect evolution mechanism analysis and quantitative precision is broken through.

The invention relates to the technical field of batteries, and provides a pole piece, a battery, a battery module and electric equipment. The tab is connected with the current collector, and the tab is a part where the pole piece is electrically connected with an external structure. The first dressing layer is stacked on the current collector, and the second dressing layer is stacked on the first dressing layer. The average particle size D50 of the active material in the first edge area of the first dressing layer is different from the average particle size D50 of the active material in the first middle area, the average particle size D50 of the active material in the second edge area of the second dressing layer is different from the average particle size D50 of the active material in the second middle area, and the sizes of the two are opposite. Therefore, the average particle size D50 of the active material in the first dressing layer and the second dressing layer can be changed, the average particle size D50 of the active material in the first edge area or the second edge area is relatively large, the current density distribution uniformity of the pole piece can be improved, the fatigue failure rate of the two ends of the pole piece is reduced, and the service life of the pole piece is prolonged.

The application relates to the technical field of power electronics, and discloses a press-contact type IGBT device packaging structure optimization method and system. The method comprises the following steps: constructing an equivalent model of a press-contact type IGBT device; constructing a differential algebraic equation for uniformly describing the equivalent model of the press-contact type IGBT device and circuit port variables; converting the differential algebraic equation into a nonlinear algebraic equation group through time domain discretization, and constructing an iteration matrix with a global state vector as a derivation object according to a solving mode of the nonlinear algebraic equation group; performing low-dimensional subspace projection on the iteration matrix based on a Krylov subspace, and combining residual minimization to solve a linear subproblem of the iteration matrix, so that current uniformity characteristic results of the press-contact type IGBT device are obtained; and the packaging structure of the press-contact type IGBT device is optimized based on current density distribution reflected by the current uniformity characteristic results. The application can improve the current uniformity and operation reliability of the system.

The application provides a kind of metal pitting defect degree evaluation method and system based on artificial intelligence, by obtaining the micro porosity distribution data of metal plate in the forming process, and the internal fluctuation signal of metal plate under the action of directional stress wave;Based on the propagation attenuation rate of internal fluctuation signal, the geometric parameters of structure abnormal area corresponding to micro porosity distribution data are generated;Obtain the current density distribution data of structure abnormal area;Micro porosity distribution data, geometric parameters of structure abnormal area and current density distribution data are input into artificial intelligence model to associate micro porosity distribution data with current density distribution data, generate the pore current coupling characteristic matrix of metal plate;According to pore current coupling characteristic matrix, the quantitative evaluation result of internal pitting defect degree of metal plate is generated;The technical scheme provided by the application realizes the dynamic quantitative evaluation of the degree of metal internal pitting defect, and breaks through the technical bottleneck of traditional single index detection method in defect evolution mechanism analysis and quantitative precision.

The embodiment of the invention provides a direct-current impedance testing method of a secondary battery, and belongs to the technical field of battery manufacturing, and the method provided by the embodiment of the invention comprises the following steps: constructing an electrochemical model of the secondary battery; according to the electrochemical model, simulating and calculating solid-phase potential, liquid-phase potential, active ion concentration and interface current density distribution of the secondary battery; according to the electrochemical model, the solid phase potential, the liquid phase potential, the active ion concentration and the interface current density distribution, the direct current impedance of a target assembly in the secondary battery is determined, and the target assembly comprises at least one of a positive plate, a negative plate and a diaphragm. Through the method provided by the embodiment of the invention, the problem that the direct current impedance of the secondary battery cannot be accurately decomposed in the existing direct current impedance decomposition mode can be solved.

The application provides a training method and device of a current density distribution identification model, the method comprising: inputting a plurality of sampling source points into the current density distribution identification model, and obtaining a loss function in the current density distribution identification model, which is constructed based on a current density distribution function and an electric field integral equation; wherein the loss function comprises a hyperbolic tangent function, a derivative of the hyperbolic tangent function and a product of the Green function; performing series expansion on the hyperbolic tangent function in the loss function, and extracting singular terms from the electric field integral equation in the series expanded loss function to obtain a plurality of singular integrals; performing inner integral calculation and outer integral calculation on each high-order singular integral in the singular integrals to determine the current density distribution function corresponding to the minimum value of the loss function on all sampling source points. The application can quickly solve the singular integrals comprising the hyperbolic tangent function, the derivative of the hyperbolic tangent function and the product of the Green function to obtain the current density distribution function.

A method and a system for optimizing a lifetime of a fuel cell system based on adjustment and constraint of a thermoelectric ratio are provided. The method includes obtaining initial reference voltages of a plurality of single-machine fuel cell systems, and performing a durability test under a normal operating condition to obtain variation relationships of reference voltage over time; monitoring an operating voltage of each of the single-machine fuel cell systems in real-time under the normal operating condition to obtain a real-time monitored voltage and a real-time voltage deviation; calculating a performance expected attenuation profile of each of the single-machine fuel cell systems under the normal operating condition; obtaining current density distribution and actual available heat of each of the single-machine fuel cell systems, and calculating a health state boundary of each of the single-machine fuel cell systems in stable operation, so as to optimize operating modes of the systems.