Method and device for detecting SOH (state of health) of capacitor in supercapacitor module and medium

Abstract

The invention discloses a capacitor SOH detection method and device in a supercapacitor module and a medium, and relates to the technical field of supercapacitors, and the method comprises the steps: obtaining a first transient temperature distribution diagram of the front surface of a circuit board and a second transient temperature distribution diagram of the back surface of the circuit board; determining a target temperature change curve of each capacitor monomer according to the plurality of first transient temperature distribution diagrams changing along with time; determining a target SOH value of each capacitor monomer according to the target working condition of the supercapacitor module, the target temperature change curve and a preset database; and judging whether a short circuit or an open circuit exists according to the second transient temperature distribution diagram. The preset database contains the corresponding relation among the working conditions, the temperature change curve and the SOH value, and the SOH value of the capacitor monomer can be determined by combining the preset database after the temperature change curve of the capacitor monomer is obtained, so that an external wire is prevented from detecting the SOH value of the capacitor monomer, and the convenience and safety of SOH detection of the capacitor monomer are improved.

Description

Technical Field

[0001] The present application relates to the technical field of supercapacitors, and in particular to a method, device and medium for detecting SOH of a capacitor in a supercapacitor module. Background Art

[0002] With the large-scale popularization of renewable energy such as photovoltaic power and wind power generation, the proportion of unstable factors affected by seasonal factors such as light intensity and light duration, as well as wind intensity has increased. There is an urgent need to develop supercapacitor energy storage systems with fast frequency modulation characteristics to achieve secondary frequency modulation or primary frequency modulation applications.

[0003] So far, double-layer supercapacitors are widely used in wind turbine pitch adjustment, instantaneous start-up and energy recovery of port machinery, and energy recovery systems of trams based on the interface adsorption and desorption mechanism. The frequency of frequency modulation operations in different application scenarios is very different. Most of the above applications are low-frequency and short-term frequency modulation operations, while renewable power grids have a high frequency of frequency modulation operations and require a long delayed frequency modulation energy storage time, which leads to the possibility that the supercapacitor system is in an uninterrupted operation state. Supercapacitor monomers have small capacity. When used for grid frequency modulation, ultra-large-scale capacitor modules or systems are often used, which makes the state estimation of each monomer, especially the health state (SOH) estimation related to service life and power station operation cost, a huge challenge. SOH represents the ratio between the actual capacity of the battery and the initial capacity, expressed as a percentage; the higher the SOH, the better the health of the battery and the smaller the capacity loss; while the lower the SOH, the worse the health of the battery and the larger the capacity loss.

[0004] For SOH detection of a small number of capacitor cells, the voltage and current signals can be obtained by directly connecting external wires, and then calculated through the model algorithm. However, when there are a large number of cells, the external wires not only take up space, make detection inconvenient, increase weight, and reduce the mass energy density and mass power density of the module or system; at the same time, due to the low resistance of the wire, it will form a device that is easy to heat, so there is a dangerous operating state where the wire heats the capacitor.

[0005] Therefore, how to avoid using external wires to detect the SOH value of capacitor cells in a supercapacitor module, improve the convenience and safety of detection, and reduce the impact on the module is a problem that technical personnel in this field need to solve. Summary of the invention

[0006] The purpose of this application is to provide a method, device and medium for detecting the SOH of a capacitor in a supercapacitor module, which is used to solve the problem of obtaining voltage and current signals through external wires and then calculating the SOH of the capacitor monomer through a model algorithm, which has the problems of inconvenient detection, high risk and great impact on the module.

[0007] In order to solve the above technical problems, the present application provides a method for detecting SOH of a capacitor in a supercapacitor module, comprising:

[0008] Controlling an infrared temperature measuring imager to photograph the front and back sides of a circuit board in a supercapacitor module, and obtaining a first transient temperature distribution diagram of the front side of the circuit board and a second transient temperature distribution diagram of the back side of the circuit board within a preset time period; wherein a plurality of capacitor cells are installed on the front side of the circuit board;

[0009] Determining a target temperature variation curve of each capacitor cell within the preset time period according to a plurality of first transient temperature distribution diagrams that vary with time;

[0010] Determine the target operating condition of the supercapacitor module, call a preset database, and determine the target SOH value of each capacitor cell according to the target operating condition, the target temperature change curve and the preset database; wherein the preset database contains the corresponding relationship between the operating condition, the temperature change curve and the SOH value of the capacitor cell;

[0011] It is determined whether there is a short circuit or an open circuit on the back side of the circuit board according to the second transient temperature distribution diagram.

[0012] In a feasible embodiment, judging whether there is a short circuit or a break on the back side of the circuit board according to the second transient temperature distribution diagram includes:

[0013] Determining the operating temperature of each position on the reverse side of the circuit board according to the second transient temperature distribution diagram;

[0014] Determining whether there is a first target operating temperature greater than a first preset value among the operating temperatures;

[0015] If the first target operating temperature is greater than the first preset value, determining that a short circuit exists at a first target position corresponding to the first target operating temperature, and marking a capacitor monomer on the front side of the circuit board corresponding to the first target position;

[0016] Determining whether there is a second target operating temperature among the operating temperatures that is less than a second preset value;

[0017] If the second target operating temperature is less than the second preset value, it is determined that a short circuit exists at a second target position corresponding to the second target operating temperature.

[0018] In a feasible embodiment, after determining the target SOH value of each capacitor cell according to the target operating condition, the target temperature change curve and the preset database, the method further includes:

[0019] If the target SOH value exceeds a preset SOH value, determining a target capacitor cell corresponding to the target SOH value, and generating first warning information including the target capacitor cell;

[0020] Determine the maximum value and the minimum value of all the target SOH values, subtract the maximum value from the minimum value to obtain a difference, and if the difference is greater than a preset difference, generate a second alarm information.

[0021] In a feasible embodiment, before calling the preset database, the method further includes:

[0022] Step A: Under preset attenuation conditions, the capacitor monomer to be tested is subjected to charge and discharge tests for different times within the range of rated voltage to half the rated voltage, the SOH value of the capacitor monomer to be tested is monitored, and the attenuation test is suspended after the SOH value of the capacitor monomer to be tested decays by a preset amplitude;

[0023] Step B: Under set test conditions, the attenuated capacitor monomer to be tested is subjected to charge and discharge tests within the range of rated voltage to half the rated voltage, the temperature of the attenuated capacitor monomer to be tested is monitored in real time to obtain a temperature change curve, and the SOH value, temperature change curve and set test conditions of the attenuated capacitor monomer to be tested are recorded;

[0024] Step C: changing the set test working condition, executing step B, until the temperature change curve of the capacitor monomer to be tested after attenuation under all the set test working conditions is obtained, and then executing step D;

[0025] Step D: starting the attenuation test in step A, allowing the capacitor unit to continue to attenuate by a preset amplitude after attenuation, and then stopping the attenuation test, and executing steps B and C until the SOH value of the capacitor unit to be tested decays to a target value;

[0026] All temperature change curves are collected, and the test working conditions corresponding to each temperature change curve and the SOH value of the capacitor monomer to be tested are sorted and combined into the preset database.

[0027] In a feasible embodiment, under a preset attenuation condition, the capacitor monomer to be tested is subjected to a charge and discharge test for different times within a range from a rated voltage to half the rated voltage, including:

[0028] Under the conditions of 25℃ temperature and 40C charge and discharge, the capacitor monomer with SOH value of 100% is tested for different times of charge and discharge in the range of rated voltage to half rated voltage.

[0029] In a feasible embodiment, determining the target SOH value of each capacitor cell according to the target operating condition, the target temperature change curve and the preset database includes:

[0030] Filtering a first temperature change curve corresponding to the target operating condition in the preset database;

[0031] Determining a correlation coefficient between each first temperature change curve and the target temperature change curve;

[0032] A target first temperature change curve corresponding to the target temperature change curve is determined according to the correlation coefficient, and a SOH value corresponding to the target first temperature change curve is used as the target SOH value.

[0033] In a feasible embodiment, monitoring the SOH value of the capacitor cell to be tested includes:

[0034] Obtaining a target current and a target voltage of the capacitor cell to be tested;

[0035] The preset relationship table is called to determine the SOH value of the capacitor cell to be tested according to the target current, the target voltage and the preset relationship table; wherein the preset relationship table contains the corresponding relationship between the current, the voltage and the SOH value.

[0036] The present application also provides a capacitor SOH detection device in a supercapacitor module, comprising:

[0037] An acquisition module is used to control the infrared temperature measurement imager to photograph the front and back sides of the circuit board in the supercapacitor module, and obtain a first transient temperature distribution diagram of the front side of the circuit board and a second transient temperature distribution diagram of the back side of the circuit board within a preset time period; wherein a plurality of capacitor cells are installed on the front side of the circuit board;

[0038] A first determination module, configured to determine a target temperature variation curve of each capacitor cell within the preset time period according to a plurality of first transient temperature distribution diagrams varying with time;

[0039] A second determination module is used to determine the target operating condition of the supercapacitor module, and call a preset database to determine the target SOH value of each capacitor cell according to the target operating condition, the target temperature change curve and the preset database; wherein the preset database contains the corresponding relationship between the operating condition, the temperature change curve and the SOH value of the capacitor cell;

[0040] A judging module is used to judge whether there is a short circuit or a break circuit on the back side of the circuit board according to the second transient temperature distribution diagram.

[0041] The present application also provides a capacitor SOH detection device in a supercapacitor module, comprising a memory for storing a computer program;

[0042] A processor is used to implement the steps of the capacitor SOH detection method in the supercapacitor module when executing the computer program.

[0043] The present application also provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps of the capacitor SOH detection method in the supercapacitor module are implemented.

[0044] The present application provides a method for detecting SOH of a capacitor in a supercapacitor module, comprising: controlling an infrared temperature measuring imager to photograph the front and back sides of a circuit board in the supercapacitor module, and obtaining a first transient temperature distribution diagram of the front side of the circuit board and a second transient temperature distribution diagram of the back side of the circuit board within a preset time period; wherein a plurality of capacitor cells are installed on the front side of the circuit board; determining a target temperature change curve of each capacitor cell within a preset time period according to a plurality of first transient temperature distribution diagrams that change with time; determining a target operating condition of the supercapacitor module, and calling a preset database, and determining a target SOH value of each capacitor cell according to the target operating condition, the target temperature change curve and the preset database; wherein the preset database contains a correspondence between the operating condition, the temperature change curve and the SOH value of the capacitor cell; and judging whether there is a short circuit or a break on the back side of the circuit board according to the second transient temperature distribution diagram. The preset database contains the corresponding relationship between working conditions, temperature change curves and SOH values. The temperature change curve of the capacitor monomer over a period of time is obtained by an infrared temperature imaging device, and the SOH value of the capacitor monomer can be determined in combination with the preset database, avoiding the use of external wires to detect the SOH value of the capacitor monomer in the supercapacitor module, reducing the impact on the module, and improving the convenience and safety of the SOH detection of the capacitor monomer. Secondly, the second transient temperature distribution diagram can also be used to determine short circuits or open circuits.

[0045] In addition, compared with the SOH detection method in which each capacitor cell is connected to a wire, infrared photography can directly obtain the temperature signals of a large number of cells at the same time. It is fast and efficient, which can reduce the detection cost and improve the safety of the system. The accuracy of infrared temperature measurement is 0.1℃, while the accuracy of thermocouple temperature measurement is 3℃. For supercapacitors that are not easy to heat up, infrared temperature measurement has higher accuracy and more sensitive feedback. Infrared temperature measurement on the circuit board side can directly visualize the hot spot temperature and see the fault point at the same time, while thermocouple temperature measurement cannot achieve this function. The SOH decay of the capacitor cell corresponding to the hot spot temperature is also the fastest. Where the temperature is high, the SOH data information of the capacitor cell corresponding to the hot spot temperature can be retrieved, which can improve the fault identification.

[0046] The beneficial effects of the capacitor SOH detection device and medium in a supercapacitor module provided in the present application correspond to the method, and the effects are as above. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] In order to more clearly illustrate the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0048] FIG1 is a flow chart of a method for detecting capacitor SOH in a supercapacitor module provided in an embodiment of the present application;

[0049] FIG2 is a structural diagram of a capacitor SOH detection device in a supercapacitor module provided in an embodiment of the present application;

[0050] FIG3 is a structural diagram of another capacitor SOH detection device in a supercapacitor module provided in an embodiment of the present application. DETAILED DESCRIPTION

[0051] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0052] The core of this application is to provide a method, device and medium for detecting SOH of capacitors in a supercapacitor module, so as to improve the convenience and safety of detection and reduce the impact on the module.

[0053] In order to enable those skilled in the art to better understand the present application, the present application is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0054] FIG. 1 is a flow chart of a method for detecting SOH of a capacitor in a supercapacitor module provided in an embodiment of the present application. As shown in FIG. 1 , the method for detecting SOH of a capacitor in a supercapacitor module includes:

[0055] S10: Controlling the infrared temperature imaging device to photograph the front and back sides of the circuit board in the supercapacitor module to obtain a first transient temperature distribution diagram of the front side of the circuit board and a second transient temperature distribution diagram of the back side of the circuit board within a preset time period; wherein a plurality of capacitor cells are installed on the front side of the circuit board.

[0056] S11: determining a target temperature variation curve of each capacitor cell within a preset time period according to a plurality of first transient temperature distribution graphs that vary with time.

[0057] S12: Determine the target operating condition of the supercapacitor module, call the preset database, and determine the target SOH value of each capacitor cell according to the target operating condition, the target temperature change curve and the preset database; wherein the preset database contains the correspondence between the operating condition, the temperature change curve and the SOH value of the capacitor cell.

[0058] S13: Determine whether there is a short circuit or an open circuit on the back side of the circuit board according to the second transient temperature distribution diagram.

[0059] In step S10, the camera of the instantaneous infrared temperature imager is used to shoot the front and back of the circuit board in the supercapacitor module to ensure that all capacitor cells in the supercapacitor module can be photographed. If the number of capacitor cells in the supercapacitor module is large, the camera's field of view can be expanded or the number of cameras can be increased for full coverage. The infrared temperature imager can be controlled to shoot the first transient temperature distribution diagram on the front of the circuit board and the second transient temperature distribution diagram on the back of the circuit board at intervals, so that the first transient temperature distribution diagram and the second transient temperature distribution diagram corresponding to different time points in the preset time period can be obtained. The accuracy of infrared temperature measurement is 0.1°C, while the accuracy of thermocouple temperature measurement is 3°C. For supercapacitors that are not easy to heat up, infrared temperature measurement has higher accuracy and more sensitive feedback.

[0060] In step S11, the temperature data displayed at each position in the first transient temperature distribution diagram corresponds to the capacitor monomer one by one. According to the multiple first transient temperature distribution diagrams that change with time, the temperature corresponding to each capacitor monomer at different time points can be recorded, so as to obtain the target temperature change curve of the capacitor monomer.

[0061] In step S12, the operating conditions in the preset database may include ambient temperature and charge and discharge rate. Accordingly, it is necessary to determine the target operating conditions of the supercapacitor module, that is, determine the ambient temperature and charge and discharge rate of the supercapacitor module, find the temperature change curve corresponding to the target operating condition in the preset database, compare the target temperature change curve obtained in step S11 with the temperature change curve corresponding to the target operating condition one by one, and determine the temperature change curve with the same or similar change characteristics as the target temperature change curve. The SOH value corresponding to the temperature change curve is the target SOH value corresponding to the target operating condition and the target temperature change curve. How to find a temperature change curve that is the same or similar to the target temperature change curve in the preset database is not limited in this embodiment of the present application, and the overlapping drawing method and the correlation coefficient method can be used.

[0062] In step S13, judging whether there is a short circuit or an open circuit on the back of the circuit board according to the second transient temperature distribution diagram specifically includes: determining the operating temperature of each position on the back of the circuit board according to the second transient temperature distribution diagram; judging whether there is a first target operating temperature greater than the first preset value in the operating temperature; if there is a first target operating temperature greater than the first preset value, determining that there is a short circuit at the first target position corresponding to the first target operating temperature, and marking the capacitor monomer on the front of the circuit board corresponding to the first target position; judging whether there is a second target operating temperature less than the second preset value in the operating temperature; if there is a second target operating temperature less than the second preset value, determining that there is an open circuit at the second target position corresponding to the second target operating temperature. Among them, marking the capacitor monomer on the front of the circuit board corresponding to the first target position is to provide a reference basis for subsequent analysis of the reasons for the high temperature of the capacitor monomer, so as to avoid directly assuming that the high temperature of the capacitor monomer is caused by the decline of electrochemical performance. Infrared temperature measurement can directly visualize the hot spot temperatures on both sides of the circuit board, and it is convenient to see the fault point.

[0063] A method for detecting SOH of a capacitor in a supercapacitor module provided in an embodiment of the present application includes: controlling an infrared temperature measuring imager to photograph the front and back sides of a circuit board in the supercapacitor module, and obtaining a first transient temperature distribution diagram of the front side of the circuit board and a second transient temperature distribution diagram of the back side of the circuit board within a preset time period; wherein a plurality of capacitor cells are installed on the front side of the circuit board; determining a target temperature change curve of each capacitor cell within a preset time period according to a plurality of first transient temperature distribution diagrams that change with time; determining a target operating condition of the supercapacitor module, and calling a preset database, and determining a target SOH value of each capacitor cell according to the target operating condition, the target temperature change curve and the preset database; wherein the preset database contains a correspondence between the operating condition, the temperature change curve and the SOH value of the capacitor cell; and judging whether there is a short circuit or a break on the back side of the circuit board according to the second transient temperature distribution diagram. The preset database contains the corresponding relationship between working conditions, temperature change curves and SOH values. The temperature change curve of the capacitor monomer over a period of time is obtained by an infrared temperature imaging device, and the SOH value of the capacitor monomer can be determined in combination with the preset database, avoiding the use of external wires to detect the SOH value of the capacitor monomer in the supercapacitor module, reducing the impact on the module, and improving the convenience and safety of the SOH detection of the capacitor monomer. Secondly, the second transient temperature distribution diagram can also be used to determine short circuits or open circuits.

[0064] In addition, compared with the SOH detection method in which each capacitor cell is connected to a wire, infrared photography can directly obtain the temperature signals of a large number of cells at the same time. It is fast and efficient, which can reduce the detection cost and improve the safety of the system. The accuracy of infrared temperature measurement is 0.1℃, while the accuracy of thermocouple temperature measurement is 3℃. For supercapacitors that are not easy to heat up, infrared temperature measurement has higher accuracy and more sensitive feedback. Infrared temperature measurement on the circuit board side can directly visualize the hot spot temperature and see the fault point at the same time, while thermocouple temperature measurement cannot achieve this function. The SOH decay of the capacitor cell corresponding to the hot spot temperature is also the fastest. Where the temperature is high, the SOH data information of the capacitor cell corresponding to the hot spot temperature can be retrieved, which can improve the fault identification.

[0065] Based on the above embodiments, the embodiments of the present application further include: if the target SOH value exceeds the preset SOH value, determining the target capacitor cell corresponding to the target SOH value, and generating a first alarm message containing the target capacitor cell; determining the maximum and minimum values ​​among all target SOH values, subtracting the maximum and minimum values ​​to obtain a difference, and if the difference is greater than the preset difference, generating a second alarm message.

[0066] In the embodiment of the present application, when one or some target SOH values ​​exceed the preset SOH value, it indicates that the target capacitor monomer corresponding to the target SOH value may have a problem of reduced electrochemical performance, and a first alarm message is generated to prompt the user to replace it. If the difference between the maximum and minimum values ​​in the target SOH value is greater than the preset difference, it may be that the heat dissipation design in the module is uneven, and a second alarm message is generated to remind the staff to perform maintenance and inspection.

[0067] Based on the above embodiment, before calling the preset database, the embodiment of the present application also includes: step A: performing different times of charge and discharge tests on the capacitor monomer to be tested in the range of rated voltage to half of the rated voltage under preset attenuation working conditions, monitoring the SOH value of the capacitor monomer to be tested, and pausing the attenuation test after the SOH value of the capacitor monomer to be tested decays by a preset amplitude; step B: performing charge and discharge tests on the attenuated capacitor monomer to be tested in the range of rated voltage to half of the rated voltage under set test working conditions, monitoring the temperature of the attenuated capacitor monomer to be tested in real time to obtain a temperature change curve, and recording the SOH value of the attenuated capacitor monomer to be tested. OH value, temperature change curve and set test working conditions; step C: change the set test working conditions, execute step B until the temperature change curve of the capacitor monomer to be tested after attenuation under all set test working conditions is obtained, and then execute step D; step D: start the attenuation test in step A, so that the attenuated capacitor monomer to be tested continues to attenuate by a preset amplitude and then stops the attenuation test, and execute steps B and C until the SOH value of the capacitor monomer to be tested decays to the target value; collect all temperature change curves, and organize and combine the test working conditions corresponding to each temperature change curve and the SOH value of the capacitor monomer to be tested into a preset database.

[0068] In step A, the embodiment of the present application does not specifically limit the preset attenuation operating conditions, and the preset attenuation operating conditions may include ambient temperature and charge and discharge rate. Specifically, at a temperature of 25°C and a charge and discharge condition of 40C (C represents the charge and discharge rate of the battery, also known as C-rate), the capacitor monomer to be tested with an SOH of 100% is subjected to different times of charge and discharge tests in the range of rated voltage to half the rated voltage. By attenuating the capacitor monomer to be tested with an SOH value of 100%, the capacitor monomer to be tested in the range of SOH values ​​from 100% to the target value can be obtained. The target value is usually 80%, because when the SOH value decays to 80%, it means that the performance of the capacitor monomer to be tested has been significantly reduced. According to the regulations, when the SOH value is less than 80%, the capacitor monomer to be tested should be replaced, so there is no need to test the temperature change curve of the capacitor monomer to be tested with an SOH value less than 80%. The present application does not specifically limit how to monitor the SOH value of the capacitor monomer to be tested. The capacitor monomer to be tested can be connected to an external wire to detect the current and voltage of the capacitor monomer to be tested, and the capacitance value of the capacitor monomer to be tested can be determined based on the current and voltage; the SOH value of the capacitor can also be determined based on the circuit principle by establishing an equivalent circuit model. The SOH value of the capacitor monomer to be tested can be monitored regularly at preset time intervals.

[0069] In step B, the test working conditions are set to include the ambient temperature and the charge and discharge rate. Step B is to obtain the temperature change curve of the capacitor monomer to be tested under the set test working conditions after the first decay in step A, and record the corresponding relationship between the SOH value of the capacitor monomer to be tested after the first decay, the temperature change curve and the set test working conditions.

[0070] In step C, the set test conditions in step B are changed, the purpose of which is to obtain the temperature change curve of the capacitor monomer to be tested after the first decay under other test conditions. Thus, the temperature change curve of the capacitor monomer to be tested after the first decay under all set conditions is obtained.

[0071] In step D, after the temperature change curves of the capacitor monomer to be tested under all set working conditions after the first attenuation are obtained. The capacitor monomer to be tested after the first attenuation is further attenuated to obtain the capacitor monomer to be tested after the second attenuation, and steps B and C are repeated to record the SOH value of the capacitor monomer to be tested after the second attenuation, as well as the temperature change curves of the capacitor monomer to be tested under all set working conditions after the second attenuation. The capacitor monomer to be tested after the second attenuation is further attenuated to obtain the capacitor monomer to be tested after the third attenuation, and steps B and C are repeated until the SOH value of the capacitor monomer to be tested decays to the target value (80%).

[0072] After the above steps are completed, all temperature change curves are collected, and the set test conditions and the SOH value of the capacitor monomer to be tested corresponding to each temperature change curve are marked, and the preset database is obtained by collating and summarizing.

[0073] To better understand the process of establishing the preset database in this application, an example is given below.

[0074] (1) At 25°C, 40°C charging and discharging, the supercapacitor monomer with SOH of 100% is tested for different times in the range of rated voltage to half the rated voltage. At the same time, the SOH of the supercapacitor monomer is monitored and the test is stopped when the SOH of the supercapacitor monomer decays to 99%.

[0075] (2) At 25°C, 1C charge and discharge, the supercapacitor cell with a SOH of 99% was charged and discharged in the range of rated voltage to half the rated voltage. At the same time, the supercapacitor cell was measured with an infrared thermometer, and the temperature change curve of the supercapacitor cell under this state (25°C, 1C charge and discharge, SOH of 99%) was recorded.

[0076] (3) While keeping the 1C charge and discharge and SOH at 99% in step (2), increase the test temperature by 1°C each time from 25°C to obtain all temperature change curves in the temperature range of 25°C to 65°C under the conditions of 1C charge and discharge and SOH at 99%. For example, the temperature change curve of the supercapacitor monomer under the conditions of 26°C, 1C charge and discharge, and SOH at 99%; the temperature change curve of the supercapacitor monomer under the conditions of 27°C, 1C charge and discharge, and SOH at 99%; and so on, the temperature change curve of the supercapacitor monomer under the conditions of 65°C, 1C charge and discharge, and SOH at 99%. Of course, the test temperature can also be selected within the range of 25°C-65°C with an interval of 2°C.

[0077] (4) While keeping the temperature in step (2) at 25°C and SOH at 99%, increase the test rate by 1C each time to obtain all temperature change curves in the range of 1C-100°C under the conditions of 25°C and SOH at 99%. For example, the temperature change curve of the supercapacitor monomer under the conditions of 25°C, 2C charge and discharge, and SOH at 99%; the temperature change curve of the supercapacitor monomer under the conditions of 25°C, 3C charge and discharge, and SOH at 99%; and so on, to obtain the temperature change curve of the supercapacitor monomer under the conditions of 25°C, 100C charge and discharge, and SOH at 99%. Of course, the test rate can also be selected at intervals of 2C within the range of 1C-100C.

[0078] (5) Start step (1), charge and discharge at 40C at 25℃, and perform different times of charge and discharge tests on supercapacitor cells with SOH of 99% in the range of rated voltage to half rated voltage. Meanwhile, monitor the SOH of supercapacitor cells and stop when the SOH of supercapacitor cells decays to 98%. Repeat steps (2)-(4) to obtain the temperature change curve of supercapacitor cells with SOH of 98% under all working conditions. This is done until the temperature change curve of supercapacitor cells with SOH of 80% under all working conditions is obtained. The attenuation amplitude of SOH of supercapacitor cells each time can be 1% or 2%, etc., which is designed according to actual needs.

[0079] Based on the above embodiments, the embodiments of the present application determine the target SOH value of each capacitor cell according to the target operating conditions, the target temperature change curve and the preset database, specifically including: screening the first temperature change curve corresponding to the target operating conditions in the preset database; determining the correlation coefficient between each first temperature change curve and the target temperature change curve; determining the target first temperature change curve corresponding to the target temperature change curve according to the correlation coefficient, and taking the SOH value corresponding to the target first temperature change curve as the target SOH value.

[0080] The temperature change curves with the target working condition in the preset database are screened out and recorded as the first temperature change curves. The correlation coefficient between each first temperature change curve and the target temperature change curve is calculated. Since the calculation of the correlation coefficient between the two temperature change curves is a prior art, a brief introduction is given here. The calculation steps are: respectively calculate the mean of the two temperature change curves (the first temperature change curve and the target temperature change curve); for each data point, calculate its deviation from the respective mean; obtain the covariance according to the sum of the deviation products of the two curves and the number of data points; respectively calculate the standard deviation of the two temperature change curves, which reflects the degree of dispersion of each curve itself; use the covariance and standard deviation to calculate the correlation coefficient r, the value of the correlation coefficient r is between -1 and 1, close to 1 indicates a strong positive correlation, close to -1 indicates a strong negative correlation, and close to 0 indicates no linear correlation. The first temperature change curve with the correlation coefficient closest to 1 is taken as the target first temperature change curve corresponding to the target temperature change curve.

[0081] Based on the above embodiments, the embodiments of the present application monitor the SOH value of the capacitor cell to be tested, specifically including: obtaining the target current and target voltage of the capacitor cell to be tested; calling a preset relationship table, and determining the SOH value of the capacitor cell to be tested according to the target current, target voltage and the preset relationship table; wherein the preset relationship table contains the corresponding relationship between current, voltage and SOH value.

[0082] In the process of conducting a large number of tests to obtain the preset database, the traditional method of obtaining voltage and current signals from the external wires of the capacitor to be tested is still used, and then the SOH value of the capacitor to be tested is determined by looking up the table. The voltage of the capacitor changes with its aging. The SOH of the capacitor can be evaluated by monitoring the voltage change of the capacitor under a specific load; the current change of the capacitor can reflect the change of its internal resistance. The SOH of the capacitor can be evaluated by monitoring the current flowing through the capacitor. The preset list contains the correspondence between current, voltage and SOH value. Once the target current and target voltage are obtained, the SOH value of the capacitor to be tested can be obtained by looking up the table. This method is relatively simple.

[0083] In the above embodiments, the capacitor SOH detection method in the supercapacitor module is described in detail, and the present application also provides a corresponding embodiment of the capacitor SOH detection device in the supercapacitor module. It should be noted that the present application describes the embodiments of the device part from two perspectives, one is based on the functional module perspective, and the other is based on the hardware perspective.

[0084] FIG2 is a structural diagram of a capacitor SOH detection device in a supercapacitor module provided in an embodiment of the present application. As shown in FIG2 , the capacitor SOH detection device in the supercapacitor module includes:

[0085] The acquisition module 10 is used to control the infrared temperature imaging device to photograph the front and back sides of the circuit board in the supercapacitor module, and obtain the first transient temperature distribution diagram of the front side of the circuit board and the second transient temperature distribution diagram of the back side of the circuit board within a preset time period; wherein, a plurality of capacitor cells are installed on the front side of the circuit board.

[0086] A first determination module 11 is used to determine a target temperature change curve of each capacitor cell within a preset time period according to a plurality of first transient temperature distribution diagrams that change with time;

[0087] The second determination module 12 is used to determine the target operating conditions of the supercapacitor module, and call the preset database to determine the target SOH value of each capacitor cell according to the target operating conditions, the target temperature change curve and the preset database; wherein the preset database contains the correspondence between the operating conditions, the temperature change curve and the SOH value of the capacitor cell.

[0088] The judging module 13 is used to judge whether there is a short circuit or a break on the back side of the circuit board according to the second transient temperature distribution diagram.

[0089] Based on the above embodiment, in a feasible embodiment, the judgment module includes:

[0090] A first determining unit is used to determine the operating temperature of each position on the reverse side of the circuit board according to the second transient temperature distribution diagram;

[0091] A first judging unit, used for judging whether there is a first target operating temperature greater than a first preset value in the operating temperature;

[0092] A second confirmation unit is used to determine that a short circuit exists at a first target position corresponding to the first target operating temperature if there is a first target operating temperature greater than a first preset value, and mark a capacitor monomer on the front side of the circuit board corresponding to the first target position;

[0093] A second judging unit, used for judging whether there is a second target operating temperature less than a second preset value in the operating temperature;

[0094] The third confirmation unit is used to determine that a second target position corresponding to the second target operating temperature has a short circuit if there is a second target operating temperature that is less than a second preset value.

[0095] Based on the above embodiment, in a feasible embodiment, it further includes:

[0096] A first alarm module, configured to determine a target capacitor cell corresponding to the target SOH value and generate first alarm information including the target capacitor cell if the target SOH value exceeds a preset SOH value;

[0097] The second alarm module is used to determine the maximum value and the minimum value among all target SOH values, and to obtain a difference by subtracting the maximum value from the minimum value. If the difference is greater than a preset difference, a second alarm message is generated.

[0098] Based on the above embodiment, in a feasible embodiment, it further includes:

[0099] The first execution module is used to perform different times of charge and discharge tests on the capacitor monomer to be tested within the range of rated voltage to half the rated voltage under preset attenuation working conditions, monitor the SOH value of the capacitor monomer to be tested, and suspend the attenuation test after the SOH value of the capacitor monomer to be tested decays by a preset amplitude;

[0100] The second execution module is used to perform a charge and discharge test on the attenuated capacitor monomer to be tested within a range from the rated voltage to half the rated voltage under the set test working conditions, monitor the temperature of the attenuated capacitor monomer to be tested in real time to obtain a temperature change curve, and record the SOH value, temperature change curve and set test working conditions of the attenuated capacitor monomer to be tested;

[0101] A third execution module is used to change the set test working condition and enter the second execution module until the temperature change curve of the capacitor unit to be tested after attenuation under all the set test working conditions is obtained, and then enter the fourth execution module;

[0102] The fourth execution module is used to start the attenuation test in the first execution module, so that the attenuated capacitor monomer continues to attenuate by a preset amplitude and then stops the attenuation test, and sequentially enters the second execution module and the third execution module until the SOH value of the capacitor monomer to be tested is attenuated to a target value;

[0103] The collection module is used to collect all temperature change curves, and organize and combine the test working conditions corresponding to each temperature change curve and the SOH value of the capacitor monomer to be tested into a preset database.

[0104] Based on the above embodiment, in a feasible embodiment, the first execution module includes:

[0105] The execution unit is used to perform different times of charge and discharge tests on the capacitor monomer to be tested with a SOH value of 100% within the range of rated voltage to half the rated voltage under the temperature of 25°C and the charge and discharge conditions of 40C.

[0106] Based on the above embodiment, in a feasible embodiment, the second determining module includes:

[0107] A screening unit, used for screening a first temperature change curve corresponding to a target operating condition in a preset database;

[0108] a fourth determining unit, configured to determine a correlation coefficient between each first temperature variation curve and a target temperature variation curve;

[0109] The fifth determining unit is used to determine the target first temperature change curve corresponding to the target temperature change curve according to the correlation coefficient, and use the SOH value corresponding to the target first temperature change curve as the target SOH value.

[0110] Based on the above embodiment, in a feasible embodiment, the first execution module includes:

[0111] An acquisition unit, used for acquiring a target current and a target voltage of a capacitor cell to be tested;

[0112] The calling unit is used to call a preset relationship table to determine the SOH value of the capacitor monomer to be tested according to the target current, the target voltage and the preset relationship table; wherein the preset relationship table contains the corresponding relationship between the current, the voltage and the SOH value.

[0113] Since the embodiments of the apparatus part correspond to the embodiments of the method part, please refer to the description of the embodiments of the method part for the embodiments of the apparatus part, which will not be repeated here.

[0114] FIG3 is a structural diagram of another capacitor SOH detection device in a supercapacitor module provided in an embodiment of the present application. As shown in FIG3 , the capacitor SOH detection device in the supercapacitor module includes: a memory 20 for storing a computer program;

[0115] The processor 21 is used to implement the steps of the capacitor SOH detection method in the supercapacitor module of the above embodiment when executing the computer program.

[0116] The capacitor SOH detection device in the supercapacitor module provided in this embodiment may include but is not limited to a smart phone, a tablet computer, a laptop computer or a desktop computer.

[0117] Among them, the processor 21 may include one or more processing cores, such as a 4-core processor, an 8-core processor, etc. The processor 21 can be implemented in at least one hardware form of a digital signal processor (DSP), a field-programmable gate array (FPGA), and a programmable logic array (PLA). The processor 21 may also include a main processor and a coprocessor. The main processor is a processor for processing data in the awake state, also known as a central processing unit (CPU); the coprocessor is a low-power processor for processing data in the standby state. In some embodiments, the processor 21 may be integrated with a graphics processing unit (GPU), which is responsible for rendering and drawing the content to be displayed on the display screen. In some embodiments, the processor 21 may also include an artificial intelligence (AI) processor, which is used to process computing operations related to machine learning.

[0118] The memory 20 may include one or more computer-readable storage media, which may be non-transitory. The memory 20 may also include a high-speed random access memory, and a non-volatile memory, such as one or more disk storage devices, flash memory storage devices. In this embodiment, the memory 20 is at least used to store the following computer program 201, wherein the computer program, after being loaded and executed by the processor 21, can implement the relevant steps of the capacitor SOH detection method in the supercapacitor module disclosed in any of the aforementioned embodiments. In addition, the resources stored in the memory 20 may also include an operating system 202 and data 203, etc., and the storage method may be temporary storage or permanent storage. Among them, the operating system 202 may include Windows, Unix, Linux, etc. Data 203 may include, but is not limited to, a first transient temperature distribution diagram and a second transient temperature distribution diagram, etc.

[0119] In some embodiments, the capacitor SOH detection device in the supercapacitor module may further include a display screen 22 , an input / output interface 23 , a communication interface 24 , a power supply 25 , and a communication bus 26 .

[0120] Those skilled in the art will appreciate that the structure shown in FIG. 3 does not constitute a limitation on the capacitor SOH detection device in the supercapacitor module, and may include more or fewer components than those shown in the figure.

[0121] The capacitor SOH detection device in the supercapacitor module provided in the embodiment of the present application includes a memory and a processor. When the processor executes the program stored in the memory, it can implement the following method: control the infrared temperature measurement imager to shoot the front and back sides of the circuit board in the supercapacitor module, and obtain the first transient temperature distribution diagram of the front side of the circuit board and the second transient temperature distribution diagram of the back side of the circuit board within a preset time period; wherein, a plurality of capacitor cells are installed on the front side of the circuit board; determine the target temperature change curve of each capacitor cell within the preset time period according to the plurality of first transient temperature distribution diagrams that change with time; determine the target operating condition of the supercapacitor module, and call the preset database to determine the target SOH value of each capacitor cell according to the target operating condition, the target temperature change curve and the preset database; wherein the preset database contains the corresponding relationship between the operating condition, the temperature change curve and the SOH value of the capacitor cell; and judge whether there is a short circuit or a break on the back side of the circuit board according to the second transient temperature distribution diagram.

[0122] Finally, the present application also provides an embodiment corresponding to a computer-readable storage medium. The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps described in the method for detecting capacitor SOH in a supercapacitor module in the above method embodiment are implemented.

[0123] It is understandable that if the method in the above embodiment is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application is essentially or the part that contributes to the prior art or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM), random access memory (RAM), disk or optical disk and other media that can store program code.

[0124] The above is a detailed introduction to the capacitor SOH detection method, device and medium in a supercapacitor module provided by the present application. The various embodiments in the specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same and similar parts between the embodiments can refer to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can refer to the method part description. It should be pointed out that for ordinary technicians in this technical field, without departing from the principles of this application, several improvements and modifications can be made to the present application, and these improvements and modifications also fall within the scope of protection of the claims of this application.

[0125] It should also be noted that, in this specification, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprise", "include" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the statement "comprises a ..." does not exclude the presence of other identical elements in the process, method, article or device including the element.

Claims

1. A method for detecting capacitor SOH in a supercapacitor module, characterized in that: include: Controlling an infrared temperature measuring imager to photograph the front and back sides of a circuit board in a supercapacitor module, and obtaining a first transient temperature distribution diagram of the front side of the circuit board and a second transient temperature distribution diagram of the back side of the circuit board within a preset time period; wherein a plurality of capacitor cells are installed on the front side of the circuit board; Determining a target temperature variation curve of each capacitor cell within the preset time period according to a plurality of first transient temperature distribution diagrams that vary with time; Determine the target operating condition of the supercapacitor module, call a preset database, and determine the target SOH value of each capacitor cell according to the target operating condition, the target temperature change curve and the preset database; wherein the preset database contains the corresponding relationship between the operating condition, the temperature change curve and the SOH value of the capacitor cell; It is determined whether there is a short circuit or an open circuit on the back side of the circuit board according to the second transient temperature distribution diagram.

2. The method for detecting capacitor SOH in a supercapacitor module according to claim 1, characterized in that: Judging whether there is a short circuit or an open circuit on the back side of the circuit board according to the second transient temperature distribution diagram includes: Determining the operating temperature of each position on the reverse side of the circuit board according to the second transient temperature distribution diagram; Determining whether there is a first target operating temperature greater than a first preset value among the operating temperatures; If the first target operating temperature is greater than the first preset value, determining that a short circuit exists at a first target position corresponding to the first target operating temperature, and marking a capacitor monomer on the front side of the circuit board corresponding to the first target position; Determining whether there is a second target operating temperature among the operating temperatures that is less than a second preset value; If the second target operating temperature is less than the second preset value, it is determined that a short circuit exists at a second target position corresponding to the second target operating temperature.

3. The method for detecting capacitor SOH in a supercapacitor module according to claim 1, characterized in that: After determining the target SOH value of each capacitor cell according to the target operating condition, the target temperature change curve and the preset database, the method further includes: If the target SOH value exceeds a preset SOH value, determining a target capacitor cell corresponding to the target SOH value, and generating first warning information including the target capacitor cell; Determine the maximum value and the minimum value of all the target SOH values, subtract the maximum value from the minimum value to obtain a difference, and if the difference is greater than a preset difference, generate a second alarm information.

4. The method for detecting capacitor SOH in a supercapacitor module according to claim 1, characterized in that: Before calling the preset database, it also includes: Step A: Under preset attenuation conditions, the capacitor monomer to be tested is subjected to charge and discharge tests for different times within the range of rated voltage to half the rated voltage, the SOH value of the capacitor monomer to be tested is monitored, and the attenuation test is suspended after the SOH value of the capacitor monomer to be tested decays by a preset amplitude; Step B: Under set test conditions, the attenuated capacitor monomer to be tested is subjected to charge and discharge tests within the range of rated voltage to half the rated voltage, the temperature of the attenuated capacitor monomer to be tested is monitored in real time to obtain a temperature change curve, and the SOH value, temperature change curve and set test conditions of the attenuated capacitor monomer to be tested are recorded; Step C: changing the set test working condition, executing step B, until the temperature change curve of the capacitor monomer to be tested after attenuation under all the set test working conditions is obtained, and then executing step D; Step D: starting the attenuation test in step A, allowing the capacitor unit to continue to attenuate by a preset amplitude after attenuation, and then stopping the attenuation test, and executing steps B and C until the SOH value of the capacitor unit to be tested decays to a target value; All temperature change curves are collected, and the test working conditions corresponding to each temperature change curve and the SOH value of the capacitor monomer to be tested are sorted and combined into the preset database.

5. The method for detecting capacitor SOH in a supercapacitor module according to claim 4, characterized in that: Under the preset attenuation conditions, the capacitor monomer to be tested is charged and discharged for different times within the range of rated voltage to half the rated voltage, including: Under the conditions of 25℃ temperature and 40C charge and discharge, the capacitor monomer with SOH value of 100% is tested for different times of charge and discharge in the range of rated voltage to half rated voltage.

6. The method for detecting capacitor SOH in a supercapacitor module according to claim 1, characterized in that: Determining a target SOH value of each capacitor cell according to the target operating condition, the target temperature change curve and the preset database includes: Filtering a first temperature change curve corresponding to the target operating condition in the preset database; Determining a correlation coefficient between each first temperature change curve and the target temperature change curve; A target first temperature change curve corresponding to the target temperature change curve is determined according to the correlation coefficient, and a SOH value corresponding to the target first temperature change curve is used as the target SOH value.

7. The method for detecting capacitor SOH in a supercapacitor module according to claim 4, characterized in that: Monitor the SOH value of the capacitor to be tested, including: Obtaining a target current and a target voltage of the capacitor cell to be tested; The preset relationship table is called to determine the SOH value of the capacitor cell to be tested according to the target current, the target voltage and the preset relationship table; wherein the preset relationship table contains the corresponding relationship between the current, the voltage and the SOH value.

8. A capacitor SOH detection device in a supercapacitor module, characterized in that: include: An acquisition module is used to control the infrared temperature measurement imager to photograph the front and back sides of the circuit board in the supercapacitor module, and obtain a first transient temperature distribution diagram of the front side of the circuit board and a second transient temperature distribution diagram of the back side of the circuit board within a preset time period; wherein a plurality of capacitor cells are installed on the front side of the circuit board; A first determination module, configured to determine a target temperature variation curve of each capacitor cell within the preset time period according to a plurality of first transient temperature distribution diagrams varying with time; A second determination module is used to determine the target operating condition of the supercapacitor module, and call a preset database to determine the target SOH value of each capacitor cell according to the target operating condition, the target temperature change curve and the preset database; wherein the preset database contains the corresponding relationship between the operating condition, the temperature change curve and the SOH value of the capacitor cell; A judging module is used to judge whether there is a short circuit or a break circuit on the back side of the circuit board according to the second transient temperature distribution diagram.

9. A capacitor SOH detection device in a supercapacitor module, characterized in that: comprising a memory for storing a computer program; A processor, configured to implement the steps of the method for detecting SOH of a capacitor in a supercapacitor module according to any one of claims 1 to 7 when executing the computer program.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the method for detecting SOH of a capacitor in a supercapacitor module according to any one of claims 1 to 7 are implemented.

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