Super capacitor module screening method applied to intelligent electric meter
By using high-temperature self-discharge test methods on smart meters, unqualified supercapacitor modules were screened, which solved the problem that the existing technology was difficult to quickly screen unqualified products in high-temperature environments, and achieved stable operation of smart meters in high-temperature environments.
Patent Information
- Application Number
- CN202411773182.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-04
- Publication Date
- 2025-05-13
AI Technical Summary
It is difficult for the prior art to quickly screen out unqualified supercapacitors, especially in the high temperature environment of smart meters, which is difficult to meet the requirements of smart meters' clocks within two days.
Using the high-temperature self-discharge test method, after storing 48H in a 70℃ high-temperature box, modules with voltage values below 3.0V were eliminated, and defective products were screened through this step.
Accelerate the internal reaction and charge diffusion of supercapacitors under high temperature environments, significantly reducing the self-discharge voltage of unqualified products, achieving the effect of quickly screening out bad products, and ensuring the stable operation of smart meters in high temperature environments.
Smart Images
Figure CN119972555A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of capacitor module screening, and more specifically, to a method for screening supercapacitor modules for smart meters. Background Art
[0002] As a new type of green energy storage device, supercapacitors have the dual functions of traditional electrolytic capacitors and batteries. Supercapacitors used in smart meters must meet the following requirements: In the case of smart meters without clock batteries, supercapacitors must ensure that the smart meter clock is not disordered for at least two days in a high temperature environment of 70°C. Therefore, the self-discharge of supercapacitors is a key factor affecting their use. However, it is currently unclear what kind of energy storage supercapacitors can be safely used as smart meters.
[0003] The self-discharge mechanism of supercapacitors can be divided into three categories: leakage current, Faraday reaction and charge redistribution. Faraday reaction and charge redistribution are greatly affected by ambient temperature. Under normal temperature, Faraday reaction and charge diffusion move relatively slowly. In a short period of time, the self-discharge voltage of this type of supercapacitor is not significantly different from that of a normal supercapacitor, and it is difficult to quickly screen out such unqualified products. High temperature environment can accelerate the internal reaction of supercapacitors and the diffusion distribution of charges. Ultimately, the self-discharge voltage of this type of supercapacitor is significantly lower than that of a normal superelectric appliance, and defective products can be quickly screened out. Therefore, high temperature self-discharge test is more suitable for screening tests using supercapacitor modules on smart meters. Summary of the invention
[0004] The purpose of the embodiments of the present application is to provide a method for screening supercapacitor modules for smart meters, and the high-temperature self-discharge test is more suitable for screening tests of supercapacitor modules used in smart meters.
[0005] To achieve the above objectives, this application provides the following technical solutions:
[0006] The present application embodiment provides a method for screening supercapacitor modules for smart meters, comprising the following steps:
[0007] Appearance inspection: Check the appearance of the supercapacitor monomer. The shell should be free of deformation and cracks; the surface should be flat, dry and free of electrolyte spills; the markings should be clear, complete and accurate;
[0008] Capacity test: the supercapacitor is tested in constant current mode on a constant current / constant voltage source. The capacity test is qualified if the capacity deviation does not exceed ±5% of the nominal value.
[0009] AC internal resistance test: use AC resistance tester to measure, the frequency of measuring voltage is 1kHz, AC current is 1mA to 10mA, if the measured internal resistance value is within the specified range, the internal resistance measurement test is qualified;
[0010] 70℃ 48H self-discharge test, testing the voltage across the capacitor after the supercapacitor module is stored in a 70℃ high temperature box for 48H, and eliminating the supercapacitor modules with a voltage value lower than 3.0V;
[0011] In the 75℃95%RH test, if the supercapacitor module has no deformation or leakage, the capacity change rate is less than 30%, and the AC internal resistance change rate is less than 4 times, the test is qualified.
[0012] The capacity test is specifically as follows:
[0013] a) Charge the supercapacitor to the rated voltage U at a constant current / constant voltage source R ;
[0014] b) When the supercapacitor is charged to the rated voltage U R Then, constant voltage charging is performed for 30 minutes;
[0015] c) After 30 minutes of constant voltage charging, discharge at a constant current of I = 10mA;
[0016] d) Record the time T1 and T2 corresponding to the voltage across the capacitor changing from U1 to U2, and calculate the capacitance value according to the following equation:
[0017]
[0018] Where: C: capacity; I: discharge current; U1: 90% U R ; U2: 50% U R ; T1: time from the start of discharge to the voltage reaching U1; T2: time from the start of discharge to the voltage reaching U2.
[0019] The specific self-discharge test at 70℃ for 48 hours is as follows:
[0020] Step 1: First, completely short-circuit the supercapacitor module for more than 24 hours to ensure that the voltage across the supercapacitor module is less than 0.5V;
[0021] Step 2: Place the fully discharged supercapacitors in parallel on the test fixture and charge them at a constant voltage of 5.0V for 10 minutes;
[0022] Step 3: After charging is complete, disconnect the power supply and test the voltage across the supercapacitor module, and remove the supercapacitor module with a voltage value lower than 4.5V;
[0023] Step 4: Place the charged supercapacitor module in a 70°C high temperature box;
[0024] Step 5: Test the voltage across the capacitor after the supercapacitor module is stored in a 70℃ high temperature box for 48 hours, and eliminate the supercapacitor modules with a voltage value lower than 3.0V.
[0025] The specific test of 75℃95%RH is:
[0026] a) Place the supercapacitor module on the test fixture, and then place it in a high temperature box at 75°C and 95% relative humidity, and perform 5.0V constant voltage charging for 500 hours;
[0027] b) After the experiment lasts for 500 hours, take out the supercapacitor module and place it at room temperature for 4 hours to check its appearance and test its capacity and AC internal resistance;
[0028] c) If the supercapacitor module has no deformation or leakage, the capacity change rate is less than 30%, and the AC internal resistance change rate is less than 4 times, the test is qualified.
[0029] Compared with the prior art, the present invention has the following beneficial effects:
[0030] At present, the supercapacitors selected for smart meters are mainly screened by appearance, capacity, AC internal resistance, leakage current and room temperature self-discharge test, among which the performance that mainly affects the use of smart meters is the supercapacitor self-discharge performance. Under normal temperature conditions, the Faraday reaction and charge diffusion movement are relatively slow. In a short period of time, the self-discharge voltage of this type of supercapacitor is not significantly different from the self-discharge voltage of a normal supercapacitor, and it is difficult to quickly screen out such unqualified products; while a high temperature environment can accelerate the internal reaction of the supercapacitor and the diffusion distribution of the charge. Ultimately, the self-discharge voltage of this type of supercapacitor is significantly lower than the self-discharge voltage of a normal superelectric appliance, and defective products can be quickly screened out. Therefore, the high temperature self-discharge test selected by the present invention is more suitable for screening tests using supercapacitor modules on smart meters. BRIEF DESCRIPTION OF THE DRAWINGS
[0031] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments of the present application will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.
[0032] Figure 1 It is a flow chart of the method of this application. DETAILED DESCRIPTION
[0033] The technical solutions in the embodiments of the present application will be described below in conjunction with the drawings in the embodiments of the present application. It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings.
[0034] The terms "comprises," "comprising," or any other variation thereof are intended to encompass non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the process, method, article, or apparatus that includes the element.
[0035] The terms "first", "second", etc. are only used to distinguish one entity or operation from another entity or operation, and should not be understood as indicating or implying relative importance, nor should they be understood as requiring or implying any such actual relationship or order between these entities or operations.
[0036] like Figure 1 As shown, the embodiment of the present application provides a method for screening supercapacitor modules for smart meters, comprising the following steps:
[0037] Appearance inspection
[0038] Under good light conditions, use visual inspection to check the appearance of the supercapacitor monomer. If it meets the following requirements, it is considered qualified in the appearance inspection test: the shell has no deformation or cracks; the surface is flat, dry and has no electrolyte spills; the markings are clear, complete and accurate;
[0039] The appearance measurement test is specifically as follows: using a vernier caliper to measure the size of the supercapacitor cell, including the height and diameter of the supercapacitor cell; if the measured size is within the specified range, the appearance inspection is qualified.
[0040] Capacity Test
[0041] a) Charge the supercapacitor to the rated voltage U at a constant current / constant voltage source R ;
[0042] b) When the supercapacitor is charged to the rated voltage U R Then, constant voltage charging is performed for 30 minutes;
[0043] c) After 30 minutes of constant voltage charging, discharge at a constant current of I = 10mA;
[0044] d) Record the time T1 and T2 corresponding to the voltage across the capacitor changing from U1 to U2, and calculate the capacitance value according to the following equation:
[0045]
[0046] Where: C capacity (F);
[0047] I: discharge current (A);
[0048] U1: 90% UR (V);
[0049] U2: 50% UR (V);
[0050] T1: time from the beginning of discharge to the voltage reaching U1 (S);
[0051] T2: Time from the start of discharge to the voltage reaching U2 (S).
[0052] The capacity test is qualified only if the capacity deviation does not exceed ±5% of the nominal value.
[0053] AC internal resistance test
[0054] Use an AC resistance tester to measure, the frequency of the measuring voltage is 1kHz, and the AC current is 1mA to 10mA. If the measured internal resistance value is within the specified range, the internal resistance measurement test is qualified;
[0055] 70℃48H self-discharge test
[0056] The specific steps of high temperature self-discharge screening test are as follows:
[0057] Step 1: First, completely short-circuit the supercapacitor module for more than 24 hours to ensure that the voltage across the supercapacitor module is less than 0.5V;
[0058] Step 2: Place the fully discharged supercapacitors in parallel on the charging test fixture and perform 5.0V constant voltage charging for 10 minutes;
[0059] Step 3: After charging is complete, disconnect the power supply and test the voltage across the supercapacitor module, and remove the supercapacitor module with a voltage value lower than 4.5V;
[0060] Step 4: Place the charged supercapacitor module in a 70°C high temperature box;
[0061] Step 5: Test the voltage across the capacitor after the supercapacitor module is stored in a 70℃ high temperature box for 48 hours, and eliminate the supercapacitor modules with a voltage value lower than 3.0V.
[0062] 75℃95%RH test
[0063] a) Place the supercapacitor module on the test fixture, and then place it in a high and low temperature box at 75℃ and 95% RH (relative humidity) for 500 hours of 5.0V constant voltage charging;
[0064] b) After the experiment lasts for 500 hours, take out the supercapacitor module and place it at room temperature for 4 hours. According to the above test method, check its appearance and test its capacity and AC internal resistance.
[0065] c) If the supercapacitor module has no deformation, leakage or other phenomena on its appearance, the capacity change rate is less than 30%, and the AC internal resistance change rate is less than 4 times, the test is qualified.
[0066] Example effect description
[0067]
[0068] The high temperature self-discharge test selected in this application is more suitable for the screening test of supercapacitor modules used in smart meters.
[0069] The above description is only an embodiment of the present application and is not intended to limit the protection scope of the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.
Claims
1. A method for screening supercapacitor modules for smart meters, characterized in that: The following steps are involved: Appearance inspection: Check the appearance of the supercapacitor unit. The shell should be free of deformation and cracks; the surface should be flat, dry and free of electrolyte spills. The logo is clear, complete and accurate; Capacity test: the supercapacitor is tested in constant current mode on a constant current / constant voltage source. The capacity test is qualified if the capacity deviation does not exceed ±5% of the nominal value. AC internal resistance test: use AC resistance tester to measure, the frequency of measuring voltage is 1kHz, AC current is 1mA to 10mA, if the measured internal resistance value is within the specified range, the internal resistance measurement test is qualified; 70℃ 48H self-discharge test, testing the voltage across the capacitor after the supercapacitor module is stored in a 70℃ high temperature box for 48H, and eliminating the supercapacitor modules with a voltage value lower than 3.0V; In the 75℃95%RH test, if the supercapacitor module has no deformation or leakage, the capacity change rate is less than 30%, and the AC internal resistance change rate is less than 4 times, the test is qualified.
2. The method for selecting supercapacitor modules for smart meters according to claim 1, characterized in that: The capacity test is specifically as follows: a) Charge the supercapacitor to the rated voltage U at a constant current / constant voltage source R ; b) When the supercapacitor is charged to the rated voltage U R Then, constant voltage charging is performed for 30 minutes; c) After 30 minutes of constant voltage charging, discharge at a constant current of I = 10mA; d) Record the time T1 and T2 corresponding to the voltage across the capacitor changing from U1 to U2, and calculate the capacitance value according to the following equation: Where: C capacity; I: discharge current; U1: 90% U R ; U2: 50% U R ; T1: time from the beginning of discharge to the voltage reaching U1; T2: The time from the start of discharge to the voltage reaching U2.
3. The method for selecting supercapacitor modules for smart meters according to claim 1, characterized in that: The specific steps of the 70℃ 48H self-discharge test are as follows: Step 1: First, completely short-circuit the supercapacitor module for more than 24 hours to ensure that the voltage across the supercapacitor module is less than 0.5V; Step 2: Place the fully discharged supercapacitors in parallel on the test fixture and charge them at a constant voltage of 5.0V for 10 minutes; Step 3: After charging is complete, disconnect the power supply and test the voltage across the supercapacitor module, and remove the supercapacitor module with a voltage value lower than 4.5V; Step 4: Place the charged supercapacitor module in a 70°C high temperature box; Step 5: Test the voltage across the capacitor after the supercapacitor module is stored in a 70℃ high temperature box for 48 hours, and eliminate the supercapacitor modules with a voltage value lower than 3.0V.
4. The method for selecting supercapacitor modules for smart meters according to claim 1, characterized in that: The specific test of 75℃95%RH is: a) Place the supercapacitor module on the test fixture, and then place it in a high temperature box at 75°C and 95% relative humidity, and perform 5.0V constant voltage charging for 500 hours; b) After the experiment lasts for 500 hours, take out the supercapacitor module and place it at room temperature for 4 hours to check its appearance and test its capacity and AC internal resistance; c) If the supercapacitor module has no deformation or leakage, the capacity change rate is less than 30%, and the AC internal resistance change rate is less than 4 times, the test is qualified.