52 results about "Impedance response" patented technology

The invention relates to the technical field of communication signal separation, and discloses a frequency spectrum segmentation method and system based on deep learning, and the method comprises the following steps: obtaining a frequency spectrum image as input, and carrying out the feature extraction of the frequency spectrum image through a deep neural network; extracting a result based on the features; mapping the capacitor array control parameters into a frequency function form; transforming the frequency function through a preset nonlinear impedance response operator to obtain a corresponding impedance response; constructing a continuity loss item of the impedance response changing along with a network prediction path in a training process; according to the gradient change condition of the impedance response; and training the neural network through a joint loss function. According to the invention, by introducing the gradient compression strategy based on the derivative norm of the control parameter, the dynamic adjustment of the amplitude of the control parameter in the high-sensitivity frequency interval is realized, and the effects that the control process is smoother and the response is more stable are obtained.

The invention discloses a physicochemical index detection method for canned food production, and relates to the technical field of food detection, and the method comprises the following steps: deploying annularly arranged near infrared spectrum, eddy current electromagnetic and biological impedance three-mode sensing units, and collecting tank reflection spectrum, eddy current loss and complex impedance response signals in a non-contact manner; extracting characteristic parameters of sulfur dioxide, heavy metals and microorganisms through wavelet packet decomposition, Hilbert transform and principal component analysis; constructing a ternary coupling correction equation set to perform cross correction on the original data, and outputting an accurate detection result; and a self-calibration mechanism and an abnormal product automatic sorting function are integrated. By constructing four core technology systems of multi-modal synchronous acquisition, cross-modal feature coupling, dynamic threshold decision and online self-calibration, lossless, efficient and multi-index parallel detection is realized, the precision is stable, the cost is reduced by 60%, and the real-time quality control and tracing requirements of a full-automatic production line are met.

The invention provides a battery impedance analysis method and device, a storage medium and computer equipment. When the battery impedance is analyzed, an EIS test is carried out on a target battery, and various electrochemical behaviors of the battery in the test process are captured through dynamic characteristics in test data, so that a DRT map generated by carrying out DRT analysis on the test data can visually display impedance response time corresponding to different electrochemical processes in a time dimension; after the response interval of each electrochemical process is determined, standard charging and discharging circulation can be carried out on the target battery, DCR testing is carried out on the target battery with a plurality of selected turns in the circulation process, impedance decomposition is carried out on DCR data obtained through testing on the basis of each response interval, and therefore real-time subdivision of overall impedance information is achieved. And finally, carrying out comparative analysis on impedance decomposition data obtained after subdividing each selected number of turns, so as to generate a high-quality impedance analysis result.

The invention relates to the technical field of electronic measurement and sensing, and discloses a capacitance monitoring method and system based on a sweep frequency resonance point, and the method comprises the steps: carrying out the coarse sweeping in an initial frequency range, obtaining an impedance spectrum, and recognizing a coarse resonance interval; carrying out fine scanning in the interval and calculating an accurate resonant frequency by adopting a quadratic interpolation method; calculating a capacitance value in combination with the mapping table; and dynamically adjusting the frequency sweeping window of the next period based on the historical resonant frequency. The system comprises an excitation signal generation unit, an impedance response acquisition unit, a coarse / fine scanning control unit, a resonant frequency calculation unit, a capacitance resolving unit and a dynamic frequency window updating unit, and integrates a temperature compensation and anomaly detection mechanism. Through the two-stage frequency sweeping and self-adaptive frequency window strategy, the monitoring period is shortened to 1 / 5 or below of that of a traditional method while it is guaranteed that the resonant frequency measurement precision is superior to 0.01 Hz, and the real-time performance, stability and environmental adaptability are remarkably improved.

The invention relates to the technical field of impedance measurement, in particular to an impedance measurement method and system for a common-mode inductor, and the method comprises the steps: obtaining voltage and current signals of the common-mode inductor in a test circuit, and obtaining frequency domain response atlas data containing impedance characteristics through time-frequency transformation; carrying out non-linear segmentation division on the frequency axis to form a plurality of frequency segmentation regions; extracting the phase amplitude of each segmented region, carrying out clustering segmentation, and recognizing an effective impedance frequency band; analyzing phase synchronization characteristics in the effective impedance section, and determining a common-mode resonant frequency point through clustering analysis; and fusing multi-section frequency region division, effective impedance section and resonance point information to finish accurate measurement of the impedance characteristic of the common-mode inductor. According to the method, through non-linear scanning and phase information joint analysis, the recognition precision of impedance response key characteristics in a broadband range is improved, the capturing capacity of parasitic parameters and resonance behaviors is enhanced, and efficient and high-precision comprehensive evaluation of the impedance characteristics of the common-mode inductor is achieved.

The application discloses a physicochemical index detection method for food can production and relates to the technical field of food detection. The method comprises the following steps: deploying a near-infrared spectrum, eddy current electromagnetic and biological impedance three-mode sensing unit in a ring arrangement, and non-contact collecting can body reflection spectrum, eddy current loss and complex impedance response signals; extracting sulfur dioxide, heavy metal and microbial characteristic parameters through wavelet packet decomposition, Hilbert transform and principal component analysis; constructing a three-element coupling correction equation group to cross correct original data and output accurate detection results; and integrating a self-calibration mechanism and an abnormal product automatic sorting function. The application realizes nondestructive, efficient and multi-index parallel detection by constructing four core technical systems, namely, multi-modal synchronous acquisition, cross-modal feature coupling, dynamic threshold decision and online self-calibration, has stable precision and reduces costs by 60%, and meets the real-time quality control and traceability requirements of a full-automatic production line.

This application provides a battery impedance analysis method, apparatus, storage medium, and computer equipment. When analyzing battery impedance, an EIS test is performed on the target battery to capture various electrochemical behaviors of the battery during the test process through the dynamic characteristics in the test data. Therefore, the DRT spectrum generated by DRT analysis of the test data can intuitively display the impedance response time corresponding to different electrochemical processes in the time dimension. After determining the response range of each electrochemical process, standard charge-discharge cycles can be performed on the target battery. During the cycle, DCR tests are performed on the target battery for multiple selected cycles, and impedance decomposition is performed on the obtained DCR data based on each response range to achieve real-time subdivision of the overall impedance information. Finally, the impedance decomposition data obtained after subdivision for each selected cycle number are compared and analyzed to generate high-quality impedance analysis results.

The invention discloses a guide rail rust-proof state monitoring system and method based on impedance detection, and relates to the technical field of electrochemical guide rail rust-proof monitoring. Impedance detection electrodes are arranged on the surface of a guide rail, alternating current excitation signals are applied, and voltage response signals and current response signals of the guide rail are synchronously collected; calculating to form guide rail impedance spectrum data and constructing an impedance spectrum curve, analyzing and separating impedance responses of different frequency bands, extracting impedance spectrum characteristic parameters representing oil film isolation capability, interface charge transfer capability and diffusion impedance characteristics, and establishing an equivalent circuit model to execute parameter inversion calculation; and solving interface mechanism parameters reflecting the integrity degree of the antirust film on the surface of the guide rail and the interface corrosion activity, and meanwhile, generating a guide rail antirust state spatial distribution diagram through spatial consistency analysis and gradient change analysis, thereby realizing the mechanism monitoring and spatial positioning identification of the guide rail antirust state.

The invention discloses a microwave wireless temperature sensor based on an electromagnetic metamaterial. According to the sensor, the 8 * 8 unit metamaterial array is constructed, so that efficient wireless collection and capture of space electromagnetic signals are realized; by constructing a metamaterial array cascaded microwave power synthesis feed network, power synthesis and cascade transmission of microwave wireless collection and capture signals are realized; based on the equivalent impedance response of microwave near-field resonance, a feed network output end cascade microwave complementary interdigital resonator is constructed, and metamaterial array microwave wireless signal collection and capture characteristic regulation and control based on the resonance response of the microwave complementary interdigital resonator are realized. Based on the idea that temperature information response and temperature information generation are isolated from each other, a temperature sensing probe of a metal sensing piece, a high-temperature-resistant ceramic shell and a metal hot branch knot is constructed, and temperature regulation and control of resonance characteristics of a microwave complementary interdigital resonator based on thermal strain response are achieved. Finally, the wireless sensing of the temperature information is realized by reading the echo characteristic information of the electromagnetic metamaterial array in real time.

This invention relates to the field of coordinated control of energy storage in new energy collection stations, and particularly to a coordinated control method for reactive power compensation of energy storage in new energy collection stations based on impedance reshaping. Based on the acquired three-phase AC signal, an analytical signal representation is obtained. Based on the analytical signal representation, a complex spectrum is obtained, and the impedance frequency response is determined. After processing with an exponentially weighted cumulative average filter, the actual impedance is obtained. Combined with the target impedance determined by the target impedance response model, the impedance error is determined. Based on the impedance error, a frequency-sensitive adjustment driving function is determined, and a new energy collection station adjustment residual loss function is constructed. The optimal complex impedance weighted path scheduling matrix is ​​determined. Simultaneously, a frequency segmentation objective function mechanism and a suppression function are introduced to construct a global optimization objective function, obtaining the optimal virtual impedance configuration. This solves the technical problems of resonance and stability issues, as well as reactive power response conflicts and low control efficiency caused by independent control strategies and a lack of coordinated adjustment.

The invention provides a bio-electricity signal and electrode impedance acquisition system and method, and relates to the technical field of bio-electricity signal acquisition and processing. According to the specific technical scheme, the integrated bio-electricity signal acquisition chip is used for generating an alternating current excitation signal with a specific frequency and a fixed amplitude through an internally integrated excitation source; continuously applying an alternating current excitation signal to one or more target electrodes through an internal analog switch array; the integrated bio-electricity signal acquisition chip is used for acquiring a mixed digital signal from a target electrode, and the mixed digital signal is formed by superposing a bio-electricity signal, a noise signal and an impedance response signal generated by an alternating current excitation signal on target electrode impedance; and the microcontroller unit is used for extracting electrode impedance information from the mixed digital signal and recovering the bio-electricity signal.

The embodiment of the invention provides a battery life determination method, electronic equipment, a storage medium and a program product. The method comprises the following steps: measuring an electrochemical impedance spectrum of a battery to be determined at at least one preset frequency point; wherein the preset frequency points correspond to different measurement frequencies; generating a full-frequency-domain electrochemical impedance spectrum of the battery to be determined according to the electrochemical impedance spectrum at the at least one preset frequency point; wherein the full-frequency-domain electrochemical impedance spectrum represents impedance responses of the battery to be determined in all frequency ranges; and determining the battery life of the to-be-determined battery according to the full-frequency-domain electrochemical impedance spectrum. The method is used for achieving the effect of improving the battery life determination accuracy.

The invention provides a diagnosis method and device for abnormal operation of an elevator. The method comprises the steps that a door lock loop conventional voltage signal, a high-frequency impedance response signal, a landing door mechanical position signal and a door lock contact micro-vibration signal are collected in real time; whether a diagnosis process is started or not is judged according to the consistency of the conventional voltage signal and the door opening and closing instruction and the voltage transient interruption condition; extracting a high-frequency impedance module value Z, an impedance angle theta, a position offset delta d, micro-vibration total energy E and principal component characteristics E1, E2 and E3; and inputting the characteristic parameters into a multi-source information fusion diagnosis model constructed based on a D-S evidence theory, respectively calculating confidence coefficients of artificial short circuit H1 and contact adhesion H2 through basic probability distribution of four evidence bodies and a D-S synthesis rule, and outputting a diagnosis result according to a decision rule. According to the method, accurate distinguishing between manual short circuit and contact adhesion of the elevator door lock loop is achieved, the diagnosis accuracy and the maintenance efficiency are remarkably improved, and potential safety hazards such as door opening and elevator walking are eliminated.

The present application relates to the field of environmental monitoring and biosensing technology, and particularly relates to a detection method and system for new pollutants in ecological environment, comprising the following steps: S100: culturing specific effector cells in a biosensing channel, and collecting trans-epithelial electrical resistance (TEER) signals of the effector cells in real time; S200: monitoring a change rate of the TEER signals, and generating an enrichment triggering instruction when the change rate exceeds a preset threshold; S300: in response to the enrichment triggering instruction, introducing a fluid to be tested, which generates the change rate, into a surface-enhanced Raman scattering (SERS) detection cavity, and starting an active enrichment unit to in-situ concentrate the fluid to be tested, so that the volume of the fluid to be tested is contracted to a detection area of a SERS substrate; the present application uses impedance response of effector cells as a preliminary screening "sentinel", realizes targeted capture of only abnormal samples with acute toxicity, avoids ineffective detection of a large number of non-toxic water samples, and significantly improves monitoring efficiency.

The invention relates to the technical field of safety detection and state monitoring of lithium ion batteries, in particular to a lithium ion battery lithium precipitation judgment method based on characteristic frequency disturbance and impedance response. The method comprises the following steps: placing a lithium ion battery to be detected in an incubator for standing, and then starting a conventional charging and discharging process; synchronously applying a characteristic single-frequency sine alternating current signal in a conventional charging and discharging process, and carrying out a single-frequency impedance test; impedance real part parameters in the single-frequency impedance test are collected according to set intervals; drawing an SOC relation graph of the impedance real part value and the charging and discharging state of charge according to the impedance real part parameters; and a sudden change inflection point of an impedance real part in the SOC relation graph is identified, and battery lithium precipitation determination is completed. Therefore, the lithium separation boundary of the battery cell under different working conditions is drawn in a mode that equipment is simple, the battery does not need to be disassembled and the lithium separation starting point is accurately recognized through dynamic response of the characteristic frequency, and the method can be suitable for the lithium ion battery cell under different working conditions.

The invention discloses an impedance identification method for a power electronic transformer based on digital-analog driving, and belongs to the technical field of transformer parameter identification, the transformer is composed of an input filter, a cascaded H-bridge rectifier, N isolated dual-active bridge modules and resistors, and each module is equipped with a direct current link capacitor; the method comprises the following steps: constructing a state space relation model; constructing a physical information neural network; training the physical information neural network by using the simulation data of the traction power electronic transformer; inputting the new operation working point and frequency data of the traction power electronic transformer into the trained physical information neural network to obtain a predicted impedance response; and constructing a prediction closed-loop input admittance matrix and performing inversion to obtain an impedance matrix of the traction power electronic transformer. The problem that the impedance identification accuracy and efficiency of the power electronic transformer are insufficient is solved.

The application discloses an alternating current charging pile control system with voltage stabilization function and relates to the technical field of smart grids.The system comprises a model calibration module, which is used for feeding back the adjusted output voltage to a digital twin virtual model for parameter calibration, starting a new control cycle according to the calibrated digital twin virtual model, and obtaining a preliminary impedance response spectrum of a charging loop; an impedance generation module, which is used for obtaining parameter configuration instructions of a high-frequency test current signal based on the preliminary impedance response spectrum, injecting the high-frequency test current signal, performing band-pass filtering and fast Fourier transform, and obtaining impedance characteristics; and a risk judgment module, which is used for extracting a multi-dimensional feature vector from the impedance characteristics, calculating a power grid risk index, and performing fault judgment to form a closed-loop optimization.The application generates multi-domain response spectra through a digital twin model, realizes advanced prediction of power grid disturbance waveforms, and enables the control process to have predictive compensation capability.

The invention relates to an intelligent microbial electrode impedance analysis device, which belongs to the technical field of electrochemical impedance spectroscopy analysis, and comprises a three-electrode system used for collecting microbial impedance signals; the response signal acquisition and conditioning module is used for preprocessing the acquired microbial impedance signal; the self-adaptive digital phase-locked amplification module adopts a synchronous orthogonal digital demodulation technology and utilizes known excitation signal digital phase information to generate an orthogonal reference signal, extract amplitude and phase information of an impedance response signal, perform self-adaptive noise suppression and decouple core parameters; the reinforcement learning optimization unit is used for evaluating a current measurement state and selecting a next frequency step length; the self-adaptive excitation module is used for generating a sine excitation voltage signal and outputting the sine excitation voltage signal to the three-electrode system; and the data display module is used for displaying the impedance spectrum and the Rct curve.

This invention provides a method for constructing a simulation model of the impedance characteristics of a circuit breaker closing resistor under damage conditions. It relates to the field of simulation model construction technology. First, a bidirectional electromagnetic-thermal-mechanical multiphysics coupled simulation model is established, including a resistor element, a clamping spring, connecting conductors, and an insulating medium. Nonlinear temperature-varying resistivity and contact resistance related to clamping force are set. The steady-state field distribution is first solved at different DC operating points, and then a swept-frequency small-signal excitation is superimposed to generate an impedance-frequency characteristic curve. Finally, the model parameters are calibrated by comparing with measured data from a healthy sample of the same model. This invention implements a joint solution strategy of DC bias steady-state and AC small-signal swept-frequency in the simulation, ensuring both the convergence stability of the strongly nonlinear electro-thermal coupling problem and realistically simulating the impedance response mechanism of the closing resistor under actual load conditions.

The invention relates to the technical field of memory control and artificial intelligence, and discloses a 3D stacked memristor array optimization method based on AI data analysis, and the method comprises the following steps: S1, extracting frequency domain impedance response data containing a resistance component and a reactance component, and constructing a local state vector reflecting a physical state; s2, in combination with the time evolution characteristics of the historical operation sequence, outputting a sensitivity graph representing the interference susceptibility degrees of the target unit and the reference unit to different frequencies; s3, determining the optimal write-in carrier frequency and write-in voltage amplitude of each layer through game iteration; and S4, generating a write-in voltage waveform subjected to frequency spectrum mask filtering, and applying the write-in voltage waveform to the target unit to complete write-in operation. According to the method, the frequency domain impedance is analyzed through the AI to predict interference, the orthogonal frequency is distributed by using the game theory, and the reverse offset signal is applied, so that efficient concurrent writing of the 3D stacked array is realized, interlayer crosstalk is effectively inhibited, and the data stability is improved.

The present application relates to the technical field of electrical sensing detection, in particular to a screen electrical aging detection method based on DC impedance drift monitoring. The specific implementation process includes: using an electrical impedance sensor to apply a detection pulse and collect impedance response, constructing an initial impedance base map to form an impedance response curve; calculating impedance drift amount and drift rate to locate dielectric relaxation decay area, extracting impedance mutation boundary to identify aging characteristics; conducting spatial diffusion analysis on the impedance mutation boundary to distinguish between gate insulating layer aging and liquid crystal contamination aging; estimating the remaining reliable life of the screen according to the aging category, and forming a self-verification aging archive. The present application combines the spatial evolution of electrical characteristics with the physical wiring or backlight heat distribution characteristics of the panel by using DC impedance drift monitoring and spatial distribution analysis technology, realizes the detection and classification of screen electrical aging, and improves the efficiency and traceability of screen aging management through life integration and register write-back mechanism.

The invention discloses a microwave wireless pressure sensor based on an electromagnetic metamaterial. According to the sensor, the 8x 8-unit metamaterial array is constructed, so that wireless energy collection and capture of space electromagnetic signals are realized; by constructing an electromagnetic metamaterial array cascade microwave power synthesis feed network, power synthesis and cascade transmission of wirelessly collected and captured electromagnetic signals are realized; based on the equivalent impedance response of microwave near-field resonance, a feed network output end cascade microwave complementary interdigital resonator is constructed, and electromagnetic metamaterial microwave wireless energy collection and capture characteristic regulation and control based on the resonance response of the microwave complementary interdigital resonator are realized. Based on the idea that pressure information response and pressure information generation are isolated from each other, a pressure sensing probe of a metal sensing piece, a ceramic shell and a metal pressure elastic diaphragm is constructed, and resonance characteristic pressure regulation and control of a microwave complementary interdigital resonator based on pressure strain response are achieved. And finally, the pressure information wireless sensing is realized by reading the echo characteristic information of the electromagnetic metamaterial array in real time.

The application provides an insulation detection control method and system based on a high-voltage direct-current power supply system, relates to the technical field of insulation detection and fault control of the high-voltage direct-current power supply system, and solves the technical problem of inaccurate fault positioning in the prior art. The method comprises the following steps: dividing a direct-current bus into multiple sub-zones and setting contactors; injecting a sweep signal between the positive and negative buses and the ground wire, collecting impedance response of each sub-zone; calculating the insulation deterioration degree based on the impedance response, injecting a synchronous traveling wave signal when the insulation deterioration degree exceeds a threshold; collecting the time difference of the arrival of the traveling wave at the first and last ends, and calculating the fault point position; and disconnecting the contactor of the corresponding sub-zone according to the fault point position, so as to realize sub-zone isolation. The application is used in the insulation state monitoring, accurate fault positioning and sub-zone isolation, fault type identification and system operation reliability optimization process of the high-voltage direct-current power supply system.

An apparatus, a system, sensor, and a method for determining dissolved oxygen content in air and aqueous medium are disclosed herein. The dissolved oxygen content may be determined by irradiating the sensor comprising at least a photo-oxidizable compound by a light irradiation source, wherein the irradiation enables the photo-oxidizable compound to change its luminescent properties based upon photo-oxidation thereby enabling the quantification of the dissolved oxygen content in the medium. The dissolved oxygen content may be captured via the impedance response generated by interdigitated conducting electrode patterns included in the sensor. The dissolved oxygen content registered by the interdigitated conducting electrode patterns may be transmitted to a user device via a short range or long-range communication via an electronic circuit embedded within the sensor.

The present invention relates to the technical field of smart grids, and discloses a wide-band impedance modeling and dominant parameter identification method, system and medium for an offshore direct-drive wind turbine. Based on the grid-side converter structure of a direct-drive permanent magnet synchronous wind turbine generator set, by establishing a unified small-signal model considering the PLL, dq current control loop, sampling and modulation delay, and LCL filter link, the positive-sequence and negative-sequence impedance analytical expressions of the unit within a wide frequency band are obtained. And a comparative analysis is carried out on the influence of typical parameters such as the PLL bandwidth, grid-connected voltage, LCL filter inductance, and filter capacitance, and their influence on the impedance response is analyzed, and it is identified that the main influence sources of the wide-band impedance of the unit are concentrated on the dynamic process inside the control system. Through the method of the present invention, accurate modeling of the wide-band impedance of a direct-drive wind turbine and identification of the dominant factors can be achieved, providing a theoretical basis and engineering reference for the analysis of the grid-connected stability of the unit, the judgment of the oscillation mechanism, and the setting of control parameters.

The application relates to the field of electronic measurement and sensing technology, and discloses a capacitive monitoring method and system based on a swept-frequency resonance point. The method comprises the following steps: obtaining an impedance spectrum by rough sweeping in an initial frequency range, and identifying a rough resonance interval; performing fine sweeping in the interval and calculating an accurate resonance frequency by using a quadratic interpolation method; calculating a capacitive value in combination with a mapping table; and dynamically adjusting a next cycle sweeping window based on a historical resonance frequency. The system comprises an excitation signal generation unit, an impedance response collection unit, a rough / fine sweeping control unit, a resonance frequency calculation unit, a capacitive calculation unit and a dynamic frequency window updating unit, and integrates a temperature compensation and an abnormality detection mechanism. By means of two-stage sweeping and an adaptive frequency window strategy, the application shortens the monitoring period to less than 1 / 5 of that of a traditional method while ensuring that the resonance frequency measurement accuracy is better than 0.01 Hz, and significantly improves real-time performance, stability and environmental adaptability.

The invention relates to the technical field of power system relay protection and automation, and discloses a power distribution network fault identification and positioning method, system, device and medium, after a fault of a power distribution network is triggered, a background noise voltage spectrum and an active input impedance spectrum of the power distribution network are collected and subjected to mutual information analysis, and a local mutual information frequency domain spectrum is obtained; searching a fault sensitive frequency band in the local mutual information frequency domain spectrum, and adaptively generating a sweep frequency excitation signal in combination with the active input impedance spectrum so as to inject the sweep frequency excitation signal into the power distribution network to obtain impedance response data; calculating the spectral entropy time-varying variance of the sweep frequency excitation signal to identify the fault type of the power distribution network; constructing a distribution parameter transmission line model of the fault line based on the impedance response data, and solving by using a virtual characteristic impedance offset principle to obtain a fault positioning result of the power distribution network; the problems that the background noise value is neglected, the frequency sweeping is blind and the efficiency is low in the existing active positioning technology are solved.

The invention discloses an ex-service battery health state assessment method and system, and the method comprises the steps: applying an AC excitation signal in a preset frequency range to a to-be-tested ex-service battery, collecting the impedance response data of the ex-service battery at a plurality of frequency points, and forming an impedance spectrum original data set; the impedance spectrum original data set is processed, and multi-dimensional parameters including high-frequency-band electrolyte resistance characteristics, middle-frequency-band charge transfer impedance characteristics and low-frequency-band diffusion impedance characteristics are extracted; based on the multi-dimensional parameters, a target factor vector representing the health state of the retired battery is constructed, and the target factor vector comprises a capacity attenuation factor and an internal resistance growth factor; inputting the target factor vector into a health state mapping model obtained by training based on a decommissioned battery historical sample, and calculating to obtain a health index of the decommissioned battery to be tested; and according to the health indexes, the retired batteries are divided into different health levels. According to the method, evaluation efficiency and evaluation precision can be considered, and efficient and accurate grading of the retired batteries is realized.

This invention discloses an online diagnostic method and system for secondary circuit virtual connection faults in relay protection devices, relating to the field of power grid relay protection technology. The method includes: setting a multi-frequency safety perturbation signal and applying it to the perturbation-diagnostic branch; simultaneously collecting perturbation response observation data at different perturbation frequency bands; extracting equivalent impedance change characteristics, response time change characteristics, attenuation process change characteristics, and inter-band discrete characteristics from the perturbation response observation data to generate a virtual connection impedance fingerprint of the secondary circuit, and performing differential comparison with a healthy impedance benchmark profile to generate a virtual connection sensitive residual spectrum; backfilling the virtual connection sensitive residual spectrum into the secondary circuit topology diagnostic map to obtain a virtual connection residual topology map, and performing residual propagation positioning along the secondary circuit functional transmission direction to determine the virtual connection fault location point. This invention achieves the proactive stimulation of the secondary circuit virtual connection impedance response under controlled operational risks, improving the online identification capability of early virtual connection states.

The application discloses a fuel cell system coolant temperature control method, device, equipment and medium. The fuel cell system coolant temperature control method comprises the following steps: collecting, by a direct-current-direct-current converter and an electrochemical impedance spectrum integrated module, impedance responses of a fuel cell stack at multiple different frequencies in real time; obtaining impedance data in a low-frequency band and a medium-high-frequency band; directly reflecting proton conduction resistance of a proton exchange membrane and mass transfer resistance of reaction gas in the fuel cell stack; and accurately characterizing a membrane hydration state of the fuel cell stack. The membrane hydration state is used for dynamically compensating a coolant inlet stack temperature target value, so that the fuel cell stack can be maintained in an optimal hydration state at all times, and efficient and stable operation of the fuel cell system is ensured. The impedance-based coolant inlet stack temperature target value compensation strategy is suitable for a starting process, a normal working process and a shutdown process of the fuel cell system, and can realize accurate control of the coolant temperature in all working conditions.