369 results about "Impedance testing" 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.

The invention provides a cell fault early warning method and system based on dynamic impedance fitting, and the method comprises the steps: carrying out the impedance test of a target battery, obtaining an impedance value at an initial moment, and charging the target battery; performing impedance recording on the target battery at each time point through the excitation current with the preset frequency to obtain a real-time impedance observation value; constructing an exponential decay model and performing impedance fitting prediction on the real-time impedance observation value at each time point to obtain a real-time impedance prediction value; and carrying out residual error fitting and deviation analysis on the real-time impedance observation value and the real-time impedance prediction value to obtain battery abnormal change monitoring data, and sending out early warning when the target battery cell has a fault. The problem that in the prior art, in the battery charging and discharging process, the battery impedance change cannot be detected in real time, and the battery fault cannot be early warned in time, so that the safety of the battery cell is poor is solved. According to the invention, the impedance abnormal change time can be fed back in time and early warning can be made, so that the safety of the battery cell is improved.

The invention provides a method for predicting the residual life of a decommissioned power battery cell, and the method comprises the steps: carrying out the impedance testing of different frequencies of a to-be-tested battery cell in a decommissioned power battery in a preset testing frequency range, obtaining the impedance response data at different frequencies, and obtaining the impedance spectrum data; utilizing scene conditions corresponding to different steps are obtained, the utilizing scene conditions comprise the temperature range and the charging and discharging multiplying power, and a target step utilizing scene is matched in combination with the step grade to which the current to-be-detected battery cell belongs; performing associated storage on the target step utilization scene and the model, capacity, internal resistance and impedance spectrum data information of the retired battery cell to form a retired battery step utilization scheme; if it is detected that the battery is in an abnormal state, an early warning mechanism is triggered, and corresponding safety protection measures including cutting off a power source and starting a cooling system are taken according to a preset processing strategy.

The invention belongs to the related technical field of fuel cells, and particularly relates to a fuel cell impedance spectroscopy rapid measurement system and method, the system is divided into an excitation current injection part, a data acquisition part and an upper computer, the upper computer adopts a DIBS signal with an excellent peak value inhibition capability and a flexible amplitude-frequency design capability as test excitation, and the test excitation part is connected with the data acquisition part; an electronic load is used as an excitation source. The upper computer can control the electronic load to generate a current excitation waveform used for impedance testing based on a DIBS signal, the electronic load injects excitation current into output current of a tested galvanic pile, the upper computer can also read sampling data of the data acquisition part, fast Fourier transform is carried out on the acquired excitation current and response voltage data, and the impedance of the tested galvanic pile is tested. And obtaining an electrochemical impedance spectrum. According to the method, the impedance measurement efficiency is improved, the hardware structure is simple, the method has a good field application prospect, a measured object can be expanded to other electrochemical systems including an electrolytic tank, and the method has good expansibility.

The invention discloses an early failure identification method and device of a battery and a storage medium, and belongs to the technical field of electrochemistry. The method comprises the following steps: carrying out impedance test on a battery by using an alternating current impedance spectroscopy measurement technology, and recording test data information of the battery in the test process; constructing an impedance information data set by taking the frequency as the serial number of the test data, taking the type of the test data as the characteristic and taking each test point as a sample; determining characteristic data of the battery, judging an electrochemical process in charging and discharging of the battery in combination with the impedance data, and establishing a neural network; and fitting the impedance data of the battery based on a neural network, dividing the weight of impedance response of each internal interface between an internal electrode and an electrolyte in the battery and a cross-linked part of the internal electrode and the electrolyte by using the neural network, and judging the battery with early failure. According to the invention, the technical problem of difficulty in early warning of battery failure is solved.

The invention discloses an ECoG electrode performance monitoring and hardware parameter optimization method, device and equipment, and relates to the field of medical technology assistion.The method comprises the steps that impedance testing and parameter testing are conducted on an ECoG electrode, and signals of all channels of the ECoG electrode are collected to achieve signal analysis; performing performance state evaluation on the target ECoG electrode based on the signal analysis result and the test result; and determining a hardware problem of the target ECoG electrode based on a signal analysis result, and realizing parameter optimization. According to the method, the electrode state can be evaluated, problems can be traced, and theoretical optimal parameter matching of the electrode can be obtained through calculation.

The invention relates to a power distribution cable line fault positioning device, and the device comprises a control unit which comprises a system host and is responsible for receiving data of each module and carrying out the comprehensive analysis and processing; the data acquisition unit provides basic data for fault positioning through a cable path instrument, measures the broadband impedance change of the cable through a broadband impedance tester, and assists in judging the fault type and position; the preliminary positioning unit is used for transmitting a high-voltage pulse signal through a pulse current generator, accurately receiving a current pulse waveform generated during discharging or breakdown through a current coupler, and preliminarily positioning a fault point; a time domain reflection measuring instrument of the accurate positioning unit accurately determines the fault position by measuring the propagation time of the high-voltage pulse signal in the cable; and the artificial intelligence processing unit performs intelligent analysis on the data by integrating machine learning and a deep learning algorithm. According to the fault positioning device and the diagnosis method, the fault of the distribution cable line can be quickly and accurately positioned, the operation is convenient, and the implementation is easy.

According to the impedance test method for the multi-layer and multi-order printed circuit board and the circuit board provided by the embodiment of the invention, the through hole is formed in the inner layer circuit board, the impedance of the inner layer circuit board is tested through the through hole, and the impedance of the inner layer circuit board is tested, so that the circuit board can work normally, and the performance and reliability of electronic equipment are improved. After a layer of outer layer circuit board is added on the outer layer circuit board, a blind hole is manufactured on the outer layer circuit board based on a through hole PAD, a test PAD is made by using the blind hole, and impedance test is performed on the added outer layer circuit board, so that the impedance of the current layer can be measured in time during layer addition, and the impedance can be measured without waiting for a finished product. The actual impedance of each layer can be measured, the rejection rate of the impedance of a final finished product is reduced, the production efficiency is improved, and the cost is reduced.

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 discloses a direct-current impedance testing method and device and a medium, and relates to the field of battery testing, and the method comprises the steps: testing impedance data of a target battery at different frequencies based on an electrochemical impedance spectroscopy testing method; based on the impedance data of the target battery under different frequencies, performing parameter fitting on the constructed equivalent circuit model to obtain impedance parameters of each component of the equivalent circuit model; determining a time domain differential equation set according to the impedance parameter of each component of the equivalent circuit model; according to the current values of the target battery at any two moments, through the time domain differential equation set, overpotential values caused by each component of the equivalent circuit model at the two moments are calculated; calculating a voltage value of the target battery at each moment according to an overpotential value caused by each component of the equivalent circuit model at each moment; calculating a DC impedance value of the target battery according to the voltage values and the current values of the target battery at the two moments; according to the invention, lossless and rapid testing of the DC impedance of the battery is realized.

The invention discloses a transformer short-circuit impedance testing device, and relates to the technical field of impedance testing instruments.The transformer short-circuit impedance testing device is characterized in that a lifting mechanism is connected between a first box body and a second box body, a filter belt is connected between the first box body and the second box body, and under the control of the lifting mechanism, the filter belt is connected with the first box body; the first box body and the second box body can be separated from each other to be opened, and in cooperation with filtering isolation after the filter belt is unfolded and driving of cooling fans and turbofans in the first box body and the second box body to airflow, it can be guaranteed that internal heat dissipation is efficient and stable when the device is unfolded for use; the first box body and the second box body are closed under the control of the lifting mechanism, and the box cover is used for covering and locking, so that the device can be folded into a totally-closed box body structure during transportation and carrying, and efficient protection during transportation and carrying and efficient heat dissipation during use are both considered; and the flexibility and the stability of the device in the long-time use process are improved to a certain extent.

The invention belongs to the field of new material testing equipment, and relates to a composite material vertical impact event damage impedance testing device which at least comprises a base assembly, a vertical impact event damage impedance testing device, a vertical impact event damage impedance testing device and a vertical impact event damage impedance testing device, the clamping plate assembly is installed above the bottom plate and is provided with a fixed plate assembly and a movable plate assembly, a composite material sample is located between the fixed plate assembly and the movable plate assembly, and the impact head assembly is installed above the clamping plate assembly and is used for carrying out an impact damage test. According to the technical scheme, the problems of vertical edge impact and arc edge impact of the composite material are effectively solved, and meanwhile, the test requirements of hemispherical impactors of multiple specifications on straight-edge samples and arc samples of multiple sizes are met; installation is convenient, operation is convenient, and the application range is wide.

The invention discloses a lithium ion battery thermal runaway early warning method and a multi-frequency real-time impedance test system, and belongs to the field of lithium ion battery safety. The method comprises the following steps: screening a frequency range sensitive to temperature change and insensitive to charge state change through an electrochemical impedance spectroscopy experiment, selecting a characteristic frequency by adopting an RReliefF algorithm, carrying out real-time monitoring on an impedance module value under the characteristic frequency, and judging a safety state and carrying out first-stage, second-stage and third-stage early warning based on a preset strategy; according to the multi-frequency real-time impedance test system provided by the invention, through multi-frequency synchronous excitation, synchronous acquisition and fast Fourier transform analysis, a multi-characteristic frequency impedance measurement period is compressed to be within 0.3 second, and thermal runaway transient impedance change can be captured. The lithium ion battery thermal runaway early warning method can achieve lithium ion battery thermal runaway full-stage grading early warning, is high in early warning accuracy and time resolution, is stable and effective in a 0-100% full SOC range and in batteries of different chemical systems, and provides reliable technical support for lithium ion battery thermal runaway safety protection.

The invention provides a chip substrate performance detection device and method, and belongs to the technical field of chip detection.The chip substrate performance detection device is characterized in that a partition plate is arranged in a detection shell to form a containing cavity and an equipment cavity, a detection isolation hood forming a detection cavity is arranged at the top of the partition plate, and a heating isolation hood forming a heating cavity is arranged at the bottom of the partition plate; the impedance tester is electrically connected with four groups of test chip probes mounted on the chip clamp and is used for acquiring an impedance spectrum sequence; the alternating current and direct current parameter tester is electrically connected with a probe matrix installed at the top of the detection isolation cover to obtain a bonding pad electrical performance matrix sequence, and the probe matrix is provided with a plurality of groups of displacement sensors used for obtaining vertical displacement feedback data; the control module is used for acquiring a substrate performance comprehensive evaluation report and transmitting the report to the display terminal; the chip substrate does not need to be transferred among different devices, a high-temperature and corrosion composite environment can be synchronously simulated, performance detection can be realized, and interference of environment change or mechanical contact on detection data in the transfer process is avoided.

The invention discloses a ripple resonance point vibration adding test method, device and equipment of a vehicle electric drive system, and relates to the technical field of intelligent automobiles, and the method comprises the steps: controlling a vehicle to operate under a plurality of different real vehicle working conditions, testing the whole vehicle high-voltage inner reticulate wave of the vehicle, and obtaining the high-voltage inner reticulate wave of the vehicle; obtaining whole vehicle ripple data corresponding to each real vehicle working condition; impedance testing is conducted on the electric driving system of the vehicle, and the resonant frequency of the electric driving system is determined based on obtained impedance data; the method comprises the following steps: carrying out initial test on an electric driving system, carrying out initial test on the electric driving system, and obtaining basic test data of the electric driving system; in the process of controlling the electric driving system to perform fixed-frequency operation according to the resonant frequency, inputting a ripple signal to the electric driving system based on the whole vehicle ripple data to obtain resonance point vibration adding test data of the electric driving system; and analyzing the basic test data and the resonance point vibration adding test data to obtain a resonance point vibration adding test evaluation result of the vehicle.

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 provides a three-dimensional noise reduction structure system drainage pipe design method, and belongs to the technical field of building drainage pipes. Discretization analysis is carried out on a three-layer structure of a spiral flow guide structure PVC pipe inner wall, an asymmetric butyl rubber damping interlayer and gradient density foamed aluminum by establishing a three-dimensional noise reduction model; and constructing a vibration transfer matrix and a noise reduction key point matrix. A spiral flow guide structure is optimized through hydraulic calculation, thickness distribution of a rubber damping layer is determined through acoustic impedance testing, foamed aluminum porosity gradient design is carried out, and a small-section noise reduction cross-correlation index is introduced to evaluate the synergistic effect of adjacent structures. The optimal material ratio is solved through a three-dimensional noise reduction optimization equation set, the noise reduction effect is predicted in combination with an acoustic response deep learning model, standardized module design is finally formed through miniaturized sample piece test verification and parameter correction, and organic unification of full-band noise reduction and modular design of the drainage pipe is achieved.

The invention provides a characteristic impedance testing method, device and equipment and a medium, and relates to the technical field of radio frequency, the characteristic impedance testing method is used for testing to obtain a characteristic impedance value of a cable, the cable is provided with an input end and an output end, and the input end of the cable is used for accessing a radio frequency signal. The characteristic impedance test method comprises the steps of controlling an input end of a cable to access a radio frequency signal, controlling an output end of the cable to be grounded, obtaining a first voltage value and a first current value of the output end of the cable, and obtaining a first impedance value according to the first voltage value and the first current value; controlling the input end of the cable to access a radio frequency signal, controlling the output end of the cable to open, obtaining a second voltage value and a second current value of the output end of the cable, and obtaining a second impedance value according to the second voltage value and the second current value; and determining a characteristic impedance value of the cable according to the first impedance modulus value and the second impedance modulus value. According to the invention, the characteristic impedance value of the cable can be tested.

The invention provides a safe charging control method and device of a lithium battery, equipment and a storage medium, and relates to the technical field of lithium batteries. The method comprises the following steps: carrying out impedance test on a lithium battery to obtain a target voltage interference signal indicating that a battery cathode responds and a battery anode does not respond; and then charging the lithium battery, and carrying out capacitance test on the cathode of the lithium battery in real time according to the target voltage interference signal to obtain the cathode capacitance value of the lithium battery in the current charging state. And when it is determined that the negative capacitance value of the lithium battery in the next charging state adjacent to the current charging state meets a preset condition, determining an electric quantity value range according to the electric quantity of the lithium battery corresponding to the current charging state. And in the subsequent charging process of the lithium battery, the electric quantity of the lithium battery is controlled to be within the electric quantity value range. According to the invention, safe charging of the lithium battery can be realized.

The invention provides an active control multi-time scale electrolytic bath impedance detection method, and relates to the field of electrolytic hydrogen production, and the method comprises the following steps: determining at least two time scales corresponding to a current detection target; acquiring electrolytic cell working condition information, and determining an optimal frequency band of a time scale corresponding to the current detection target based on the electrolytic cell working condition information; determining a signal amplitude based on the working condition information of the electrolytic cell; determining a data acquisition interval corresponding to the time scale corresponding to the current detection target based on the working condition information of the electrolytic cell; based on the optimal frequency band, the signal amplitude and the data acquisition interval corresponding to each time scale, performing multi-frequency-band alternate scanning on the electrolytic cell to obtain scanning data; the method and the device have the advantage that the precision and the efficiency of the impedance measurement of the electrolytic cell under the dynamic working condition are improved.

The invention relates to the technical field of grid connection of new energy units, in particular to a control parameter identification method and system for a grid-connected converter of a new energy unit, a storage medium and a processor. The method comprises the following steps: establishing a high-frequency impedance model of a new energy unit grid-connected system, and determining to-be-identified parameters including a proportionality coefficient of a current inner ring of a converter, an integral coefficient of the current inner ring of the converter and control delay of the converter; harmonic voltage disturbance under different frequencies is applied, harmonic currents of a unit under different frequencies are measured, then impedance values under three different frequencies are obtained, the impedance values under the three different frequencies are input into a high-frequency impedance model of the new energy unit grid-connected system, and the high-frequency impedance model of the new energy unit grid-connected system is obtained. And solving the high-frequency impedance model of the new energy unit grid-connected system to obtain a to-be-identified parameter. The model involved in the method is low in order, the control parameters of the current inner loop of the converter can be obtained only through a small number of impedance tests and equation set calculation, and the method has the advantages of being high in identification efficiency and accuracy.

The invention relates to the technical field of electrical equipment testing, and discloses a high-precision anti-interference intelligent transformer short-circuit impedance testing machine which comprises an isolation power supply module and a testing host module, an electrostatic shielding layer is arranged in the isolation power supply module, a suspension working power supply isolated from power grid noise is provided for a testing host, and the anti-interference capability is improved from the source. The test host module integrates a power management and inversion module to generate a controllable three-phase AC excitation signal, and the central processing and control module performs closed-loop feedback control on a test current according to a high-precision synchronously acquired signal, so that an external voltage regulator is replaced, and automatic stabilization of a test condition is realized. According to the invention, tedious manual adjustment is not needed, full automation of the testing process is realized, and the precision, repeatability and safety of short-circuit impedance testing are remarkably improved.

The invention discloses a DC side impedance modeling method for a soft switch of a power distribution network, and the method comprises the steps: taking an inverter in an SOP as an example, building a small signal equation of an electrical part and a controller part, enabling the electrical part to be modeled in a system coordinate system, and enabling the controller part to be modeled in a control coordinate system; performing simultaneous solution on small signal equations of an electrical part and a controller part by utilizing a relation between a control coordinate system and a system coordinate system to obtain an inverter direct current side impedance model; similarly, a rectifier direct current side impedance model in the SOP is obtained, stability judgment is carried out by utilizing a Middlebrok criterion, and the influence of system parameters on the stability is analyzed; a test system is built in Matlab / Simulink, and a parallel current source is adopted to carry out small disturbance impedance test to verify the effectiveness of the built impedance model; and on the basis of a Matlab / Simulink test system, verifying the effectiveness of the influence of system parameters on the stability.

The utility model provides a camera module elargol impedance testing device. The camera module elargol impedance testing device comprises an upper cover and a base, the upper surface of the base is provided with a containing groove used for containing the camera module, and the upper cover is detachably arranged on the base; the upper surface of the base is provided with a connecting guide pin used for being electrically connected with the test box. The lower surface of the upper cover is provided with a switching copper block and a plurality of test PINs, and the test PINs are electrically connected with the switching copper block. According to the camera module testing device, the testing PINs are fixedly arranged at the upper cover, so that the testing PINs can be ensured to be in contact with the same point of different camera modules during testing each time, the detection precision can be improved, meanwhile, different testing PINs correspond to different testing point positions, and it can be ensured that the testing device completes detection of different point positions of the camera modules; in addition, the structure is simple, operation is rapid and convenient, and the working efficiency can be correspondingly improved.

The utility model relates to a probe card probe pressure impedance test bench which comprises a material placing bench, a position adjusting mechanism, a detection mechanism, a microscope and a rack. The detection mechanism is positioned between the microscope and the material placing table through the rack; the detection mechanism comprises a connecting plate, an ejector pin and a display panel, a through hole is formed in the middle of the connecting plate, and the ejector pin is Z-shaped. The utility model has the advantages that the ejector pin is arranged above the probe card, and the probe card ascends and descends through the position adjusting mechanism, so that the pin pressure values and impedance values of different OD quantities of the probe card can be measured; the Z-shaped structure of the ejector pin and the upper part of the ejector pin are provided with holes, so that the shielding space is reduced, a microscope can conveniently observe the butt joint condition of the ejector pin and the probe head of the probe card from top to bottom, and the pin alignment efficiency and the test accuracy are improved.

The invention relates to the technical field of medical rehabilitation treatment, and discloses a self-adaptive functional electrical stimulation system based on bimodal feedback and a control method. The system comprises a main control module, a stimulation output module, an electroneurographic signal detection module, a biological impedance test module and a safety isolation module. The main control module comprises a safety current determination unit, a stimulation control unit and a dynamic calibration unit which are respectively used for determining an individualized initial safety current based on neural action potential feedback, controlling treatment stimulation output and dynamically calibrating a safety current upper limit according to biological impedance change before and after stimulation. According to the invention, through bimodal feedback of electroneurographic signals and biological impedance, individualized calibration and real-time dynamic optimization of stimulation parameters are realized, and the problem that the treatment effect and safety are difficult to guarantee due to the fact that traditional functional electrical stimulation depends on experience setting and lacks physiological feedback is solved; and the accuracy, safety and adaptability of rehabilitation treatment are remarkably improved.

The embodiment of the invention discloses a transformer winding deformation diagnosis method and device, electronic equipment and a storage medium. The method comprises the following steps: constructing a short-circuit impedance test device and a capacitance test device; carrying out a transformer short-circuit impedance test based on the short-circuit impedance test device to obtain a transformer short-circuit impedance change trend; winding capacitance testing is carried out based on the capacitance testing device, and a winding capacitance data change trend is obtained; according to the transformer short-circuit impedance change trend and the winding capacitance data change trend, jointly diagnosing whether the transformer winding is deformed or not; the internal relevance between the short-circuit impedance and the winding capacitance and the winding space size is summarized and analyzed according to the relation between the short-circuit impedance and the winding capacitance, so that the diagnosis accuracy of winding deformation can be improved, and support is provided for making a transformer maintenance strategy.

A display apparatus and a test method therefor. The display apparatus comprises a display substrate (11), and an integrated circuit (12) and a flexible circuit board (13) separately bound and connected to the display substrate (11). The display substrate (11) comprises multiple first substrate pads (111A) and multiple second substrate pads (111B). The integrated circuit comprises a test signal end and multiple first connection pads (121). The display substrate (11) or the integrated circuit (12) comprises a first switch unit (S1) and a second switch unit (S2). At least two first connection pads (121) are electrically connected to the test signal end by means of the first switch unit (S1), and at least two second substrate pads (111B) are electrically connected to the test signal end by means of the second switch unit (S2). The integrated circuit (12) detects the status of the binding connection between the integrated circuit (12) and the display substrate (11), or between the flexible circuit board (13) and the display substrate (11), by means of controlling the connection and disconnection of the first switch unit (S1) and the second switch unit (S2), respectively, such that an impedance test signal of the test signal end passes through test pathways in which the first switch unit (S1) and the second switch unit (S2) are located.

The invention provides a multi-port coupled cable signal abnormity determination method and a related device, and the method comprises the steps: controlling N signal injection modules to input a coupling sweep frequency signal to a to-be-detected cable through the implementation of the embodiment of the invention; receiving M second signals and M standard reflection coefficients from the cable to be detected; determining M third signals based on the M second signals and the M standard reflection coefficients; and determining a fusion signal spectrum under the frequency fk based on the M third signals, wherein the fusion signal spectrum is used for determining a signal abnormal condition of the to-be-detected cable. Therefore, multi-port coupling and synchronous injection are realized at the head end of the cable, and the excitation energy and the signal-to-noise ratio of the broadband impedance test are remarkably improved through superposition and data fusion of multi-path signal energy, so that high-precision positioning and reliable evaluation of the latent defect of the cable are realized under a complex working condition.

The utility model discloses a detection circuit for a blood glucose testing device, the blood glucose testing device comprises a test paper reaction unit and a processing unit, and the test paper reaction unit comprises an impedance testing electrode pair and a current testing electrode pair; the processing unit comprises an impedance detection module, a current detection module and a potential tracking module, the impedance detection module is connected with the impedance test electrode pair and used for testing the impedance of the blood glucose sample, the impedance detection module comprises a signal generator, and the signal generator is used for applying an alternating current signal or a direct current signal to the impedance test electrode pair; the current detection module and the potential tracking module are respectively connected with the current test electrode pair, the current detection module can apply excitation voltage to the current test electrode pair for testing the current of the blood glucose sample, and after the excitation voltage is disconnected, the potential tracking module can test the attenuation potential of the current test electrode pair. The attenuation potential is measured, and the attenuation potential can be used as one of blood glucose calibration parameters, so that the blood glucose detection accuracy can be improved.