274 results about "Ac impedance" patented technology

The invention relates to a fuel cell test system integrated with an electrochemical alternating current impedance test function, which comprises a fuel cell stack, an air supply unit, a fuel supply unit, a cooling supply unit, a control unit, an acquisition and driving unit and an electrochemical impedance measurement system, the output ends of the air supply unit, the fuel supply unit and the cooling supply unit are connected with the fuel cell stack, the acquisition and driving unit is connected with the fuel supply unit, the control unit is connected with the acquisition and driving unit, and the electrochemical impedance measurement system is connected with the fuel cell stack and the control unit. By adopting the fuel cell test system, method and device integrated with the electrochemical alternating-current impedance test function, the processor and the computer readable storage medium, rapid measurement and impedance calculation of electrochemical impedance in a fuel cell stack test process are realized, the integration level is high, the cost is greatly reduced, the operation is simple, and the test efficiency is high. Errors caused by repeated setting of load parameters are avoided, the measurement efficiency is high, and the measurement precision is high.

A thermal runaway sign detection device includes a measurement unit that measures a voltage fluctuation in a first mode in which a number of times that a fluctuating current is output from the secondary battery and voltage fluctuation of the secondary battery in response to the fluctuating current is measured is first number of times, and in a second mode in which the number of times is second number of times less than the first number of times. A detection unit detects a sign of thermal runaway in the secondary battery when a rate of change in a real part of an AC impedance obtained based on the voltage fluctuation measured by the measurement unit at the fluctuating current of a predetermined frequency at which an imaginary part of the AC impedance of the secondary battery calculated based on the voltage fluctuation becomes zero, is greater than a threshold value.

The invention discloses a lithium battery AC impedance spectroscopy time domain and frequency domain conversion method and system, and relates to the technical field of battery data processing, and the method comprises the steps: carrying out the electrochemical impedance spectroscopy measurement of a to-be-measured lithium battery module, and obtaining the discrete impedance data of the electrochemical impedance spectroscopy; simulating the lithium battery module to be tested by using a preset equivalent circuit to obtain a fitting relationship between the circuit parameters of the preset equivalent circuit and the discrete impedance data; based on the discrete impedance data and the fitting relationship, constructing a target loss function about a regularization coefficient; determining an optimal regularization coefficient by taking the minimum value of the target loss function and combining relaxation time distribution precision meeting a preset condition as an optimization target; and converting the discrete impedance data into a continuous function on a time domain by using a regularization method based on an optimal regularization coefficient to obtain relaxation time distribution of the lithium battery module to be tested. According to the method, the technical problem that the polarization process in a battery electrochemical system cannot be effectively identified by traditional electrochemical impedance spectroscopy analysis is relieved.

The invention belongs to the technical field of battery energy storage, and discloses a method, system, equipment and medium for evaluating the internal temperature of an energy storage lithium ion battery, and the method comprises the steps: obtaining the AC impedance data of the battery at a characteristic frequency, including a real part, an imaginary part, a module value and a phase angle; inputting the real part, the imaginary part, the module value and the phase angle into a battery internal temperature estimation model to obtain the internal temperature of the battery in the current state; the characteristic frequency is the frequency that the Pearson correlation coefficients of the real part, the imaginary part, the module value and the phase angle and the temperature meet correlation, and the frequency that the Pearson correlation coefficients of the real part, the imaginary part, the module value and the phase angle and the state of charge meet ircorrelation. According to the method, the real thermal state in the battery is reflected through the impedance data, and high-precision estimation of the internal temperature of the battery is achieved. Only the characteristic frequency is measured, so that the test time can be greatly shortened; the temperature data can be quickly estimated, the evaluation response speed is obviously improved, and the method has high engineering application value.

The invention discloses a lithium battery ohmic impedance on-line measurement method based on a charging working condition, and the method comprises the steps: carrying out the charging current request of a time segment: requesting different charging currents according to the time segment when a BMS is in a fast charging constant current stage; data acquisition and queue management: acquiring voltage and current data of the battery cells in real time, and respectively storing the voltage and current data in a voltage sequence queue and a current sequence queue; performing time-phased FFT analysis and impedance calculation by using an impedance weighted average method: performing FFT analysis on data of each frequency band, calculating alternating-current impedance under a target frequency, and taking a real part of the alternating-current impedance as ohmic impedance; and obtaining ohmic impedance by adopting an impedance weighted average method: carrying out weighted average on the ohmic impedance of each frequency band to obtain final ohmic impedance. According to the method, the ohmic impedance of the lithium battery can be dynamically monitored on line, the precision is high, and additional hardware does not need to be added.

The invention provides a distribution line fault detection and positioning device and a searching method, the device comprises a transmitter and a receiver, the transmitter injects alternating current and direct current signals to a fault line to reproduce a ground fault, current is output by the transmitter, flows through the fault line, enters the ground at a fault ground point and returns to the transmitter, and the receiver receives the fault line. The transmitter measures direct current impedance and alternating current impedance of a fault line according to received signals, a proper positioning mode is given according to the measured impedance, under the determined positioning mode, the transmitter transmits corresponding signals to the fault line, the receiver analyzes and processes the received current signals and direct current pulse signals at the moment, and the fault line is positioned according to the current signals and the direct current pulse signals. And determining a line fault position. The distribution line fault detection and positioning device and the searching method are reasonable in design, simple to operate, convenient to use and carry, and can quickly solve various fault types such as low-resistance faults, high-resistance faults, arc grounding faults and interphase short-circuit faults.

The invention provides an energy storage battery production line process intelligent detection method and system, and relates to the technical field of energy storage battery production detection. Collecting AC impedance and temperature data to generate a performance distribution diagram; performing charging identification on an abnormal area and determining a defect type; carrying out pulse discharge test on the abnormal region to calculate a capacity loss rate; and marking unqualified products according to the capacity loss rate and adjusting process parameters. The method can accurately identify the performance defect of the battery monomer, improve the detection precision and the production efficiency, and effectively reduce the defective product rate.

The invention relates to the technical field of batteries, in particular to a battery charging and discharging control method and device, a battery and terminal equipment, and the method comprises the steps: obtaining an impedance real part; the impedance real part is obtained according to the alternating current impedance spectrum of the target battery under the preset excitation signal frequency; acquiring the current internal temperature of the target battery according to the impedance real part and a temperature calculation formula; querying a pre-stored maximum charge-discharge rate table according to the current charge state and the current internal temperature of the target battery to obtain a current maximum charge-discharge rate; and controlling the target battery to perform charging and discharging operation according to the current maximum charging and discharging rate. Therefore, the target battery is charged and discharged by using the accurate charge-discharge rate, battery abuse can be prevented, the service life of the battery is prolonged, and the safety of the battery is ensured.

The invention provides a sampling modulation excitation signal phase acquisition device for an alternating current impedance method in the technical field of lithium battery detection. Comprising an excitation current AC signal synchronous extraction module, a signal in-phase and anti-phase switching control module, a phase adjustment module, a signal high gain and amplitude limiting module and a phase adjustment signal output module. The excitation current AC signal synchronous extraction module, the signal in-phase and anti-phase switching control module, the phase adjustment module, the signal high gain and amplitude limiting module and the phase adjustment signal output module are connected in sequence. The method has the advantage that the alternating-current impedance test precision is greatly improved.

The internal short circuit detection method comprises the following steps: acquiring training data and test data; training a preset deep learning model by using the training data to obtain an internal short circuit prediction model; the input information of the deep learning model comprises a relaxation time distribution function, characteristics multiplied by the relaxation time distribution function and characteristics multiplied by the electrochemical alternating current impedance spectroscopy; calculating internal short circuit probability distribution corresponding to input information of test data by using the internal short circuit prediction model; and determining an internal short circuit detection result of the lithium ion battery corresponding to the test data according to the internal short circuit probability distribution.

The invention discloses a high-power alternating-current impedance excitation circuit, a control method thereof and an electrolysis test system, and belongs to the technical field of power supplies and power electronics, the circuit is used as an alternating-current power supply in a high-capacity electrolysis test power supply, and the circuit is controlled by a controller to output an alternating-current signal so as to carry out an impedance test on an electrolytic bath. Compared with a full-bridge circuit, the alternating-current impedance excitation circuit adopts the multi-level converter, so that the output current harmonic content is low, the electrolysis efficiency is improved, the equipment loss is reduced, the economical efficiency of an electrolysis system is improved, stable operation of an electrolytic bath is ensured, and electrolysis interruption or faults caused by voltage fluctuation are reduced.

The invention provides an alternating-current impedance detection method and device for an unmanned aerial vehicle, which do not depend on additional hardware, can reduce the cost of alternating-current impedance detection of a battery of the unmanned aerial vehicle, is easy to operate and implement, and comprises the following steps: controlling the unmanned aerial vehicle to vibrate and fly; the vibration flight can enable the load side of a power system of the unmanned aerial vehicle to generate power change so as to generate vibration of an electric signal, and the vibration of the electric signal enables the battery side of the unmanned aerial vehicle to generate an alternating current disturbance signal; collecting current and voltage data of the battery of the unmanned aerial vehicle during vibration flight, and calculating the alternating current impedance of the battery of the unmanned aerial vehicle according to the collected current and voltage data.

The invention relates to the technical field of charge and discharge detection, and discloses a multichannel EIS charge and discharge in-situ test system and method, and the system comprises a DC charge and discharge module which is used for carrying out the constant-current, constant-voltage or cyclic charge and discharge test of a battery; the alternating current impedance test module is connected in parallel with the direct current charging and discharging module and is used for applying an alternating current disturbance signal to the battery and collecting impedance response in the charging and discharging process; and the unified clock module is used for providing a synchronous triggering reference signal for the direct current charging and discharging module and the alternating current impedance test module. The direct current charging and discharging module and the alternating current impedance test module are designed to be of a parallel connection normally-connected structure, no relay switching is needed, continuous and uninterrupted online EIS test in the charging and discharging process is achieved, contact resistance drift and transient errors caused by physical circuit switching in a traditional scheme are effectively avoided, and the reliability of the EIS test is improved. And the stability and repeatability of the test are obviously improved.

The invention relates to a high-precision temperature detection system based on an alternating-current impedance bridge. The high-precision temperature detection system comprises a double-resistance bridge circuit, a lock-in amplifier and a differential circuit, the double-resistor bridge circuit comprises a resistive temperature sensor and a standard resistor which are connected in series, and the phase-locked amplifier is a digital phase-locked amplifier realized based on an FPGA (Field Programmable Gate Array). Wherein the initial potential of a first voltage measurement end arranged at the midpoint of the double-resistor bridge circuit is zero by adjusting the two excitation signals which are loaded to the double-resistor bridge circuit and have the same frequency and opposite phases before temperature measurement; in the temperature measuring process, the lock-in amplifier detects the potential of the first voltage measuring end and the voltage at the two ends of the standard resistor through the differential circuit, then the resistance value of the resistance-type temperature sensor is calculated by combining the resistance value of the standard resistor, and then the temperature of the resistance-type temperature sensor is reduced. According to the invention, the anti-interference capability can be improved, and the measurement precision of 0.1 mK level can be reached near 273K.

The invention relates to the technical field of inductor manufacturing methods, in particular to a preparation method of an inductor with high and excellent conductivity, which comprises the following steps: S1, winding a coil, namely winding a wire coated with an insulating layer into a hollow shape, and arranging lead parts at two ends of the coil; s2, stripping an insulating layer: stripping the insulating layer of the lead part; and S3, carrying out mold pressing on the magnetic core, carrying out mold pressing on a mixture of a magnetic material around the coil, and exposing a lead end for connecting an external terminal. A wire coated with an insulating layer is wound into a hollow shape, the two ends of a coil are extended to be lead ends, then the insulating layer of the lead part is stripped, a paint film at the lead position of the coil is pre-stripped in advance, and then hot press molding is performed, so that the surface flatness of the lead and an electrode is high, the alternating current impedance is small, and an electroplated layer on the surface of the lead and the electrode is continuous; and the design is not limited to the thickness of the paint film, so that the paint film can be designed to be very thick, and the short circuit defect can reach 0 ppm.

The invention discloses an AEM water electrolysis membrane electrode failure diagnosis method. The method comprises the following steps: inputting carrier waves with different alternating-current amplitudes when the AEM water electrolysis membrane electrode is in normal operation, carrying out carrier wave analysis, determining the magnitude of the alternating-current amplitudes, and obtaining a standard spectrogram of electrochemical alternating-current impedance and total harmonic distortion in a normal state; the method comprises the following steps: monitoring the operation of an AEM water electrolysis membrane electrode, entering a diagnosis mode after performance change, inputting a carrier wave, carrying out an electrochemical AC impedance test and a total harmonic distortion test at the same time, and carrying out Fourier transform processing on an output electrochemical AC impedance signal to obtain an electrochemical AC impedance spectrum; processing the output harmonic signal to obtain a total harmonic distortion spectrum; and comparing the total harmonic distortion spectrum with the standard spectrogram obtained in the step 1 by combining the electrochemical alternating current impedance spectrum, and identifying the failure type of the AEM water electrolysis membrane electrode. The method can effectively diagnose the failure mode of temperature change, electrolyte metering change and cathode and anode pressure change of the AEM water electrolysis membrane electrode.

The invention relates to the technical field of fuel cells, and discloses an excitation source quality control device and method for fuel cell on-line impedance measurement, a signal compensation module is used for carrying out quality control on an excitation source for alternating current impedance on-line test, and a controller carries out harmonic component analysis on a fuel cell response output signal obtained after a disturbance signal is injected; and if the corresponding harmonic component is greater than a preset threshold value, the controller calculates a compensation component according to the harmonic component deviation, integrates all the compensation components and outputs the integrated compensation components to the signal compensation module, and the signal compensation module compensates the excitation source for the AC impedance online test according to the integrated compensation components, so that the accuracy of the excitation waveform is ensured. Experiments prove that according to the fuel cell alternating current impedance online test system, the frequency output precision is within 0.1%, the phase difference between alternating current voltage and current signals is smaller than 0.1 degree, sine wave waveform distortion is smaller than 1%, and the high-precision alternating current impedance test requirement is met.

The invention discloses a relay state diagnosis method and system, electronic equipment and a storage medium. The method comprises the following steps: sending a preset frequency voltage to a to-be-tested relay to obtain an AC impedance value corresponding to the preset frequency voltage, and diagnosing the health state of the to-be-tested relay through the AC impedance value. According to the invention, the voltage difference between the two ends of the relay is not detected any more, and the health state of the relay at each position is diagnosed by directly detecting the electrochemical alternating-current impedance spectrum of the relay, so that the problem that the half-damage condition that the relay is not adhered or cannot be attracted cannot be diagnosed in the prior art is solved; and under the condition that the main negative relay is not connected with the terminal system, correct diagnosis cannot be made through the voltage difference between the two ends of the main negative relay.

The utility model discloses an ultrasonic beauty instrument based on multi-feedback automatic adjustment. The ultrasonic beauty instrument comprises a transducer, a drive circuit, a single chip microcomputer, an alternating current impedance detection unit, a temperature detection unit and a voltage and current detection unit. The skin impedance is detected through the alternating current impedance detection unit, the output of the driving circuit is adjusted, and then the ultrasonic intensity of the transducer is adjusted; the skin surface temperature is detected through the temperature detection unit, when it is detected that the skin temperature reaches a threshold value, output of ultrasonic waves is stopped, and a user is protected from being scalded; an output ultrasonic signal is monitored in real time through the voltage and current detection unit to adjust the frequency of an ultrasonic excitation signal output by the driving circuit, so that the transducer works on a resonance point all the time, automatic frequency tracking is achieved, and the accuracy of the output ultrasonic power is improved. Therefore, frequency tracking is carried out through multiple feedback modes of voltage and current detection, temperature detection and alternating current impedance detection, and the ultrasonic output intensity is automatically adjusted, so that a better use effect is achieved, and the use experience of a user is improved.

The invention provides a non-isolated LED power supply minuteness-removing turn-off circuit, which comprises a second power supply processing module, a minuteness-removing turn-off module and an LED lamp module, and is characterized in that the second power supply processing module is used for converting a high-voltage direct-current power supply into an LED lamp module working power supply; the micro-brightness removal turn-off module is arranged between the output end of the second power supply processing module and the LED lamp module and comprises a direct-current impedance conversion unit, an alternating-current impedance conversion unit and a switching tube, and the switching tube is arranged on a direct-current loop; and the control unit of the second power supply processing module reduces the DC voltage and the non-isolated AC induced voltage to be below the set voltage through the switching signal and the DC impedance conversion unit and the combined action of the switching signal and the AC impedance conversion unit, thereby realizing the minuteness-removing turn-off of the LED lamp module. According to the invention, contactless switch control can be realized, circuit loss is reduced, and working noise is reduced.

The embodiment of the invention discloses a fuel cell system fault processing method and device, and the method comprises the steps: carrying out the AC impedance spectrum test of a fuel cell, obtaining an AC impedance spectrum, building an equivalent circuit model for the reaction process of the fuel cell, carrying out the fitting of the equivalent circuit model according to the AC impedance spectrum, and obtaining the fault of the fuel cell system. Obtaining impedance data corresponding to each reaction process of the fuel cell; determining residual data between the impedance data corresponding to each reaction process of the fuel cell and the corresponding theoretical data; determining a data change trend of the impedance data according to the residual data; and performing fault diagnosis according to the data change trend to obtain a fault diagnosis result of the fuel cell. According to the fuel cell system fault processing method provided by the invention, the fault of the fuel cell can be diagnosed timely, accurately and comprehensively, the reliability and durability of the fuel cell system are improved, and the service life of the fuel cell is prolonged.

A device includes an AC impedance circuit to apply an AC excitation signal to a set of battery cells of a battery pack. The device includes a controller to determine a battery pack identification (ID) value from a battery pack identification (ID) circuit of the battery pack, calculate an impedance value of the battery pack based on the AC excitation signal, identify a maximum charging rate to charge the battery pack using the battery pack ID value of the battery pack and the impedance value of the battery pack, where the battery pack is one of at least two battery packs having a same battery pack ID value with different maximum charging rates, and set a charging rate to charge the battery pack using the maximum charging rate.

The invention relates to a lithium ion battery state-of-charge estimation method and device and a medium, and relates to the technical field of energy storage battery state monitoring, and the method comprises the steps: selecting a single frequency sampling point from an electrochemical impedance spectrum of a lithium ion battery, collecting the AC impedance of the lithium ion battery, obtaining the real part variable quantity of the AC impedance of the sampling point, and calculating the real part variable quantity of the sampling point; fitting the variable quantity of the sampling point with the corresponding charge state to obtain a first slope; and according to the linear relationship between the first slope and the charging current, calculating the state of charge of the lithium ion battery by measuring the real part of the charging current and the alternating current impedance in real time. Therefore, in the normal charging process of the lithium ion battery, the state-of-charge information of the battery can be accurately obtained, so that the working condition of the battery is optimized, and the safety of the battery and the whole system is improved.

The invention discloses a fault diagnosis method, device and equipment for a fuel cell and a storage medium. The fault diagnosis method of the fuel cell comprises the following steps: analyzing fusion fault data according to an alternating current impedance spectrum of a newly added fuel cell; analyzing the reliability of the fused fault data; when the reliability of the fused fault data reaches a preset fusion threshold value, using the fused fault data to train a preset fault diagnosis model; and diagnosing the fault type of the fuel cell through the trained fault diagnosis model. According to the technical scheme of the invention, the fault diagnosis model can be continuously adjusted according to the fused fault data, so that the fault diagnosis model can be adaptively adjusted according to the aging of the fuel cell and the change of the operation environment, and the accuracy of a fault diagnosis result is ensured.

A battery pack includes a set of blocks of battery cells, where each of the blocks is connected in series, and a set of AC impedance circuits, where each of the AC impedance circuits is electrically connected to at least one of the blocks of battery cells in the set of blocks of battery cells to apply an AC excitation signal to the at least one of the blocks in the set of blocks. The battery pack includes a controller configured to: calculate an impedance value for each of the at least one of the blocks of battery cells based on the AC excitation signal applied to each of the at least one of the blocks of battery cells, and adjust a parameter of the battery pack based on the calculated impedance value for each of the at least one of the blocks of battery cells.

A multi-objective optimization method for a circular wireless charging coil of an electric vehicle comprises the following steps: constructing an equivalent circuit model of an S-S type resonance compensation topological structure of a wireless power transmission system, and carrying out alternating current impedance analysis on the equivalent circuit model to obtain an expression of system output power and transmission efficiency; determining an optimization target according to the derived system output power and transmission efficiency expression; building a circular wireless charging coil model, determining a wireless charging coil design variable needing to be optimized, and determining a constraint condition; and carrying out parameter optimization by adopting an improved multi-target samson swarm algorithm to obtain optimal design parameters of the wireless charging coil of the wireless power transmission system. According to the method, the problem that the transmission power and efficiency of the wireless power transmission system are unstable when a coupling mechanism of the wireless power transmission system deviates is solved; the optimized wireless charging coil can effectively improve the stability of wireless charging of the electric vehicle.

A computer-implemented method for Li-plating detection of a cell of a power battery. The method includes: obtaining a plurality of AC impedance values for the cell measured at a plurality of States of Charge (SOCs), in which the plurality of AC impedance values are measured in a non-driving state of a vehicle; fitting the AC impedance values as a function of SOC based on the plurality of AC impedance values; and calculating a goodness of fit for the function, and calculating a Li-plating score for the cell based on the goodness of fit, in which the Li-plating score is used to indicate a degree to which Li-plating occurs in the cell.

The invention discloses a cell health state estimation method and system based on AC impedance, and the method comprises the steps: obtaining a plurality of sample health state values of a sample cell under each aging path based on a plurality of preset aging paths and a plurality of preset sample cells; according to a preset characteristic frequency, carrying out an AC impedance test on the sample cell corresponding to each sample health state value to obtain a sample real part impedance value corresponding to each sample health state value; fitting the plurality of sample health state values and the plurality of sample real part impedance values corresponding to the plurality of sample cells to obtain an estimation model of the sample health state values converted along with the sample real part impedance values; and obtaining a real part impedance value corresponding to the target test cell according to the characteristic frequency, so as to obtain the health state value estimation value of the target test cell from the estimation model according to the real part impedance value, thereby improving the estimation efficiency and precision.

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.

The invention relates to the technical field of lithium battery charging equipment, in particular to an overcharge protection lithium battery charger which comprises a shell, a charging protection board circuit and an output power port. The charging protection board circuit is provided with a monitoring protection module, a mechanical protection module and a logic control module. The monitoring protection module accurately identifies an overcharge abnormal state by measuring a lithium battery AC impedance spectrum in real time, and rapidly triggers the electronic protection unit to execute a cut-off action. And if the electronic protection fails, the mechanical protection module acts quickly, and the charging loop is physically disconnected. The logic control module coordinates automatic switching of the two protection modes, and the intelligence and reliability of protection are improved. The lithium battery charger is simple and reasonable in structure, high in monitoring sensitivity and rapid and reliable in protection action, has a perfect redundancy protection structure and a convenient reset mechanism, effectively overcomes the defects in the prior art, and remarkably improves the safety performance and reliability of the lithium battery charger.