A capacitor for new energy vehicles and a method for preparing the same

Abstract

The present invention relates to the technical field of capacitor preparation, and in particular to a capacitor for new energy vehicles and a preparation method thereof, the method comprising: welding the capacitor core, installing a heat sink and assembling a shell after welding; constructing a three-dimensional model to obtain gap distribution information to determine a glue injection strategy, executing the determined glue injection strategy to complete the glue injection; obtaining an infrared thermal image video of a performance test process, processing frame by frame to determine the grayscale change rate, and determining the eligibility of thermal conductivity based on the grayscale change rate; determining a temperature concentration area for unqualified thermal conductivity, determining the cause of unqualified thermal conductivity based on the distribution uniformity of the temperature concentration area, accurately adjusting parameters based on the determined cause, and preparing according to the adjusted preparation process until the thermal conductivity is qualified; the capacitor comprises: a plurality of capacitor cores, a heat sink and a shell. The present invention improves the heat dissipation effect of the capacitor and thus improves the production quality of the capacitor.

Description

Technical Field

[0001] The present invention relates to the technical field of capacitor preparation, and in particular to a capacitor for new energy vehicles and a preparation method thereof. Background Art

[0002] In the field of new energy vehicles, capacitors are key components in the electric drive system, and their performance directly affects the performance and life of the vehicle. However, in the actual application of capacitors for new energy vehicles, the heat generated by ripple current is difficult to dissipate, which has become an urgent problem to be solved.

[0003] Ripple current refers to high-frequency current, which generates heat inside the capacitor. Since the electric drive system of new energy vehicles usually requires capacitors to have high energy storage density and fast charging and discharging capabilities, the capacitor will experience frequent charge and discharge cycles during operation, resulting in the generation of ripple current. When these ripple currents flow inside the capacitor, they interact with components such as the capacitor's resistance and inductance, thereby generating heat.

[0004] However, the structure of capacitors used in new energy vehicles is usually compact and the space is limited, which makes it difficult to dissipate heat. If the heat cannot be discharged in time, the temperature inside the capacitor will rise, which will affect the performance and life of the capacitor. Especially in high temperature environments, the thermal management problem of capacitors is more prominent. Excessive temperature will cause the electrolyte inside the capacitor to evaporate, the electrode material to degrade, and other problems, thereby accelerating the aging process of the capacitor.

[0005] Chinese Patent Publication No.: CN118448163A discloses a method for preparing a capacitor and a capacitor, the preparation method includes: providing a ceramic material, and preparing the ceramic material into a plurality of ceramic layers; providing a conductive paste, and applying the conductive paste to the plurality of ceramic layers respectively to form an electrode layer on the ceramic layer, the conductive paste includes copper; alternately stacking the ceramic layers printed with the electrode layer along a first direction to obtain a ceramic laminate; firing the ceramic laminate to obtain a capacitor to be sealed; providing an end electrode material, and arranging the end electrode material at both ends of the capacitor to be sealed along a second direction to obtain a ceramic capacitor to be fired, wherein the first direction and the second direction are perpendicular; firing the ceramic capacitor to be fired to obtain a capacitor. The inner electrode of the capacitor adopts a copper inner electrode, the inner electrode has a low internal resistance, good connectivity with the copper outer electrode, and low contact resistance, which reduces the heat and loss during the use of the capacitor and improves the life of the capacitor.

[0006] It can be seen that the method for preparing a capacitor and the capacitor have the following problems: the invention coats a conductive slurry on a ceramic layer to form an electrode layer, and uses a copper inner electrode as the internal electrode of the capacitor, thereby reducing the heat generation and loss of the capacitor during use. However, the invention lacks monitoring of the capacitor preparation process, and cannot determine the heat generation and heat dissipation of the capacitor when it is working, resulting in low production quality of the capacitor. Summary of the invention

[0007] To this end, the present invention provides a capacitor for new energy vehicles and a preparation method thereof, so as to overcome the problem in the prior art that the preparation process of the capacitor is lacking in monitoring, the heat generation and heat dissipation of the capacitor during operation cannot be determined, and the production quality of the capacitor is low.

[0008] To achieve the above object, on the one hand, the present invention provides a method for preparing a capacitor for a new energy vehicle, comprising:

[0009] Pre-treating the positive and negative welding surfaces of several capacitor cores to sequentially perform negative welding and positive welding, and installing a heat sink and a housing to form a semi-finished capacitor when welding is completed;

[0010] A three-dimensional model is constructed based on the semi-finished capacitor to obtain the gap distribution information of the semi-finished capacitor, the semi-finished capacitor is divided into a plurality of regions with equal volume, the number of gaps with a gap width less than a preset width in any region is counted to determine the glue filling strategy, and the glue filling is completed to obtain the finished capacitor;

[0011] Processing the infrared thermal imaging video of the finished product capacitor performance test process frame by frame to determine the grayscale change rate to determine the eligibility of the thermal conductivity efficiency;

[0012] For finished capacitors with unqualified thermal conductivity, determine the distribution uniformity of the temperature concentration area to adjust the preset temperature / preset duration of the welding process, or adjust the glue filling pressure of the glue filling process;

[0013] The finished capacitor is prepared according to the adjusted preparation process until the thermal conductivity efficiency is qualified.

[0014] Furthermore, the process of determining the glue filling strategy based on the number of gaps includes:

[0015] Comparing the number of gaps with a preset number, and counting the number of regions where the number of gaps is greater than the preset number;

[0016] comparing the area percentage of the number of areas to the total number of areas with a preset percentage;

[0017] Determining the glue pouring strategy as regional glue pouring based on the comparison result that the regional percentage is greater than the preset percentage;

[0018] The glue pouring strategy is determined to be overall glue pouring based on the comparison result that the area percentage is less than or equal to the preset percentage.

[0019] Furthermore, under the condition of determining to perform glue pouring in different regions, the number of gaps corresponding to each region is arranged in descending order, and glue pouring is performed according to the arrangement result.

[0020] Furthermore, the process of processing the infrared thermal imaging video frame by frame to determine the grayscale change rate includes:

[0021] Extract each frame of the infrared thermal imaging video and perform grayscale processing to determine the grayscale average value;

[0022] Determine the time difference between the frame image corresponding to the maximum grayscale average value and the frame image corresponding to the standard grayscale average value, and determine the grayscale difference between the maximum grayscale average value and the standard grayscale average value;

[0023] Determine the ratio of the grayscale difference to the time difference as the grayscale change rate;

[0024] Among them, a corresponding relationship between grayscale value and temperature is preset, and the standard grayscale average value is the grayscale average value corresponding to the normal working temperature of the finished capacitor.

[0025] Further, the process of determining the eligibility of thermal conductivity based on the grayscale change rate includes:

[0026] Comparing the grayscale change rate with a preset change rate;

[0027] The thermal conductivity efficiency is determined to be unqualified based on a comparison result that the grayscale change rate is less than the preset change rate.

[0028] Furthermore, for finished capacitors with unqualified thermal conductivity efficiency, the process of determining the cause of the unqualified thermal conductivity efficiency based on the distribution uniformity of the temperature concentration area includes:

[0029] For the frame image corresponding to the maximum grayscale average value, a preset grayscale value is used as an edge, and an area with a grayscale value greater than the preset grayscale value is determined as a temperature concentration area;

[0030] Counting the number of the temperature concentration areas in any region, and calculating the distribution variance based on the number;

[0031] comparing the distribution variance with a preset variance;

[0032] Determining, based on the comparison result that the distribution variance is less than the preset variance, that the reason why the thermal conductivity efficiency is unqualified is that the welding process is unqualified;

[0033] Based on the comparison result that the distribution variance is greater than or equal to the preset variance, it is determined that the reason why the thermal conductivity efficiency is unqualified is that the glue filling process is unqualified.

[0034] Further, under the condition that the welding process is determined to be unqualified, the preset variance is subtracted from the distribution variance to obtain a first difference, and based on the comparison result that the first difference is greater than the first preset difference, it is determined to reduce the preset welding temperature by the temperature adjustment coefficient.

[0035] Further, based on the comparison result that the first difference is less than or equal to the first preset difference, it is determined to reduce the preset welding time by the time adjustment coefficient.

[0036] Furthermore, under the condition that the glue filling process is determined to be unqualified, the distribution variance is subtracted from the preset variance to obtain a second difference, and based on the comparison result that the second difference is greater than the second preset difference, it is determined to increase the glue filling pressure by the first pressure adjustment coefficient; based on the comparison result that the second difference is less than or equal to the second preset difference, it is determined to increase the glue filling pressure by the second pressure adjustment coefficient.

[0037] On the other hand, the present invention provides a capacitor prepared by using the method for preparing a capacitor for a new energy vehicle, comprising:

[0038] A plurality of capacitor cores for storing electrical energy;

[0039] A heat sink is disposed between the capacitor cores to conduct the heat generated by the capacitor cores to the outside of the capacitor;

[0040] A housing is used to encapsulate the capacitor core and the heat sink.

[0041] Compared with the prior art, the beneficial effect of the present invention lies in that the present invention determines the distribution of gaps in the semi-finished capacitor by constructing a three-dimensional model of the semi-finished capacitor. The narrower the gap, the greater the resistance to the flow of the glue, requiring higher pressure or longer glue filling time to fill it, and easily causing some areas to be unable to be fully potted. The glue filling strategy is determined according to the distribution of the narrower gaps. For the situation where there are more narrow gaps, regional glue filling is adopted, and the glue filling sequence is determined according to the number of narrow gaps. Glue filling is started from the position area with a large number of narrow gaps, thereby improving the glue filling quality; a performance test is performed on the finished capacitor after glue filling, and the temperature change during the performance test process is monitored in real time. The qualification of the thermal conductivity efficiency is determined based on the infrared thermal imaging video. The higher the thermal conductivity efficiency, the faster the heat dissipation rate, and the high heat generated by the ripple current of the capacitor can be dissipated in time, thereby reducing the impact on the electrical performance of the capacitor. For unqualified thermal conductivity efficiency, the parameters of the glue filling process and the welding process are adjusted according to the determined reasons, thereby improving the production quality of the capacitor.

[0042] Furthermore, the present invention determines the grayscale value according to the frame image in the infrared thermal imaging video, and determines the temperature in the capacitor in real time according to the grayscale value. The capacitor is a three-dimensional shape, and it is difficult to obtain a subtle temperature distribution image inside the capacitor by using conventional thermometers and other means. The temperature in the capacitor can be intuitively seen by using thermal infrared imaging means, and the image is grayscaled to determine the specific temperature value according to the grayscale value, so that the temperature change rate of the capacitor can be accurately determined according to the grayscale change rate, thereby characterizing the thermal conductivity efficiency of the capacitor, improving the evaluation benchmark of thermal conductivity, thereby improving the monitoring accuracy of the capacitor preparation process, and further improving the production quality of the capacitor.

[0043] Furthermore, under the condition that the thermal conductivity efficiency is unqualified, the present invention determines the reason for the unqualified thermal conductivity efficiency based on the uniformity of the distribution of the temperature concentration area. The more uniform the distribution of the temperature concentration area is, the more it is due to the unqualified welding process, the welding temperature is too high or the welding time is too long, which affects the electrical performance of the capacitor and generates more heat than a normal capacitor, resulting in unqualified thermal conductivity. The uneven distribution of the temperature concentration area indicates that the glue filling process is unqualified. Due to insufficient glue filling pressure, the flow time of the glue in the semi-finished capacitor is too long, resulting in poor fluidity of the glue that first enters the semi-finished capacitor, resulting in greater resistance to the flow of the glue in the gap, resulting in uneven glue filling, disordered distribution of the temperature concentration area of ​​the capacitor, increasing the glue filling pressure, and reducing the flow time of the glue, thereby further improving the production quality of the capacitor.

[0044] Furthermore, the present invention inserts a heat sink between the capacitor cores, and the heat sink is in direct contact with the capacitor core to form a good heat conduction channel, which can quickly dissipate the heat generated by the ripple current, reduce the impact of high temperature on the capacitor performance, and further improve the production quality of the capacitor. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 This is a flow chart of a method for preparing a capacitor for new energy vehicles according to an embodiment of the present invention;

[0046] Figure 2 A flow chart for determining a glue filling strategy for an embodiment of the present invention;

[0047] Figure 3 A flow chart for determining the eligibility of thermal conductivity for an embodiment of the present invention;

[0048] Figure 4 This is a schematic diagram of the structure of a capacitor for new energy vehicles according to an embodiment of the present invention;

[0049] Explanation of the accompanying drawings: 1. capacitor core, 2. heat sink, 3. housing. DETAILED DESCRIPTION

[0050] In order to make the objects and advantages of the present invention more clearly understood, the present invention is further described below in conjunction with embodiments; it should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0051] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the protection scope of the present invention.

[0052] It should be noted that, in the description of the present invention, terms such as "up", "down", "left", "right", "inside" and "outside" indicating directions or positional relationships are based on the directions or positional relationships shown in the drawings. This is merely for the convenience of description and does not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation on the present invention.

[0053] In addition, it should be noted that in the description of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0054] See also Figure 1-Figure 3 As shown, Figure 1 This is a flow chart of a method for preparing a capacitor for new energy vehicles according to an embodiment of the present invention; Figure 2 A flow chart for determining a glue filling strategy for an embodiment of the present invention; Figure 3 Flow chart for determining the eligibility of thermal conductivity for an embodiment of the present invention.

[0055] An embodiment of the present invention provides a method for preparing a capacitor for a new energy vehicle, comprising:

[0056] Step S1, determining the positive electrode welding surface and the negative electrode welding surface of a plurality of capacitor cores 1, pre-treating each welding surface to sequentially perform negative electrode welding and positive electrode welding, and after welding, installing the heat sink 2 and assembling the housing 3 to form a semi-finished capacitor;

[0057] Step S2, constructing a three-dimensional model based on the semi-finished capacitor to obtain gap distribution information of the semi-finished capacitor, dividing the semi-finished capacitor into a plurality of regions with equal volume, determining the number of gaps with a gap width less than a preset width in any region based on the gap distribution information, determining a glue pouring strategy based on the number of gaps, and executing the determined glue pouring strategy to complete glue pouring to obtain a finished capacitor;

[0058] Step S3, performing a performance test on the finished capacitor and obtaining an infrared thermal imaging video of the test process, processing the infrared thermal imaging video frame by frame to determine a grayscale change rate, and determining the eligibility of thermal conductivity based on the grayscale change rate;

[0059] Step S4, determining a temperature concentration area for the unqualified thermal conductivity, determining the cause of the unqualified thermal conductivity based on the distribution uniformity of the temperature concentration area, adjusting a preset temperature or a preset duration under the condition that the welding process is determined to be unqualified, and adjusting the glue pouring pressure under the condition that the glue pouring process is determined to be unqualified;

[0060] Step S5, preparing a finished capacitor according to the adjusted preparation process until the thermal conductivity efficiency is qualified.

[0061] Specifically, pre-treatment of the welding surface includes but is not limited to cleaning the welding surface to remove oil stains and applying flux to improve welding quality.

[0062] Specifically, welding the negative electrode first and then the positive electrode can reduce the risk of short circuit between the positive and negative electrodes.

[0063] Specifically, the three-dimensional model of the semi-finished capacitor may be constructed using, for example, SolidWorks software, which is not specifically limited.

[0064] Specifically, the preset gap width is a value corresponding to the median of historical measured values ​​of the gaps in the finished capacitor.

[0065] Specifically, the performance test of the finished capacitor is carried out in accordance with specifications, including but not limited to GB / T10190-2015 "Capacitor Inspection Methods" and GB / T 2693-2001 / IEC 60384-1:2016 "Fixed Capacitors for Electronic Equipment Part 1: General Specifications", without specific limitation.

[0066] Specifically, an infrared thermal imager such as the Huashengchang DT-979E thermal imager can be used to obtain the infrared thermal imaging video of the test process. The specific model and parameters are not limited as long as they meet the requirements.

[0067] Specifically, the process of determining the glue filling strategy based on the number of gaps includes:

[0068] Comparing the number of gaps with a preset number, and counting the number of regions where the number of gaps is greater than the preset number;

[0069] comparing the area percentage of the number of areas to the total number of areas with a preset percentage;

[0070] Determining a glue pouring strategy of pouring glue in different regions based on the comparison result that the region percentage is greater than the preset percentage;

[0071] Based on the comparison result that the area percentage is less than or equal to the preset percentage, it is determined to adopt the overall glue pouring strategy.

[0072] Specifically, the value range of the preset number is set to [5, 15], and 7 is preferred in the embodiment of the present invention; the value range of the preset percentage is set to [30%, 60%], and 40% is preferred in the embodiment of the present invention.

[0073] Specifically, the total number of regions is determined according to the volume of the capacitor, which is not specifically limited. For example, a capacitor with a volume of 416 mm×190 mm×160 mm can be divided into 10 regions with a volume of 41.6 mm×190 mm×160 mm.

[0074] Specifically, under the condition of determining the glue filling for each region, the number of gaps corresponding to each region is arranged in descending order, and glue filling is performed according to the arrangement result.

[0075] Specifically, glue filling is started from the area with a large number according to the arrangement result.

[0076] Specifically, the process of processing the infrared thermal imaging video frame by frame to determine the grayscale change rate includes:

[0077] Extract each frame of the infrared thermal imaging video and perform grayscale processing to determine the grayscale average value;

[0078] Determine the time difference between the frame image corresponding to the maximum grayscale average value and the frame image corresponding to the standard grayscale average value, and determine the grayscale difference between the maximum grayscale average value and the standard grayscale average value;

[0079] Determine the ratio of the grayscale difference to the time difference as the grayscale change rate;

[0080] Among them, a corresponding relationship between grayscale value and temperature is preset, and the standard grayscale average value is the grayscale average value corresponding to the normal working temperature of the finished capacitor.

[0081] Specifically, the grayscale average value is output by the computer based on the image intelligence, and the grayscale value and temperature are in a one-to-one correspondence. The correspondence between the grayscale value and the temperature can be calibrated experimentally. You can choose to use a standard object with a known temperature (such as a black body) to calibrate the infrared thermal imager, and record the corresponding grayscale values ​​at different temperatures to establish the correspondence between temperature and grayscale value. There is no specific limitation.

[0082] Specifically, the process of determining the eligibility of thermal conductivity based on the grayscale change rate includes:

[0083] Comparing the grayscale change rate with a preset change rate;

[0084] Determining that the thermal conductivity efficiency is unqualified based on a comparison result that the grayscale change rate is less than the preset change rate;

[0085] The thermal conductivity efficiency is determined to be qualified based on a comparison result that the grayscale change rate is greater than or equal to the preset change rate.

[0086] Specifically, the value range of the preset change rate is set to [8 / min, 14 / min], and 10 / min is preferred in the embodiment of the present invention.

[0087] Specifically, under the condition that the thermal conductivity efficiency is unqualified, the process of determining the cause of the unqualified thermal conductivity efficiency based on the distribution uniformity of the temperature concentration area includes:

[0088] For the frame image corresponding to the maximum grayscale average value, a preset grayscale value is used as an edge, and an area with a grayscale value greater than the preset grayscale value is determined as a temperature concentration area;

[0089] Counting the number of the temperature concentration areas in any region, and calculating the distribution variance based on the number;

[0090] comparing the distribution variance with a preset variance;

[0091] Determining, based on the comparison result that the distribution variance is less than the preset variance, that the reason why the thermal conductivity efficiency is unqualified is that the welding process is unqualified;

[0092] Based on the comparison result that the distribution variance is greater than or equal to the preset variance, it is determined that the reason why the thermal conductivity efficiency is unqualified is that the glue filling process is unqualified.

[0093] Specifically, the preset grayscale value in the embodiment of the present invention is the grayscale value corresponding to 50° C.; the value range of the preset variance is set to [1.5, 2.5], and 2.0 is preferred in the embodiment of the present invention.

[0094] Specifically, under the condition that the welding process is determined to be unqualified, the preset variance is subtracted from the distribution variance to obtain a first difference, and based on the comparison result that the first difference is greater than the first preset difference, it is determined to reduce the preset welding temperature by the temperature adjustment coefficient.

[0095] Specifically, based on the comparison result that the first difference is less than or equal to the first preset difference, it is determined to reduce the preset welding time by the time adjustment coefficient.

[0096] Specifically, the value range of the first preset difference is set to [0.5, 0.8], and 0.6 is preferred in the embodiment of the present invention; the value range of the temperature adjustment coefficient is set to [0.93, 0.98], and 0.95 is preferred in the embodiment of the present invention; the value range of the duration adjustment coefficient is set to [0.92, 0.95], and 0.93 is preferred in the embodiment of the present invention.

[0097] Specifically, the adjustment process of the temperature adjustment coefficient and the time adjustment coefficient is: the product of the parameters originally set in the preparation process and the adjustment coefficient is the adjusted parameter value. For example, the original welding temperature is 240°C, and after adjustment using the temperature adjustment coefficient, it is 240°C×0.95=228°C, which can be rounded off to 230°C.

[0098] Specifically, under the condition that the glue filling process is determined to be unqualified, the distribution variance is subtracted from the preset variance to obtain a second difference, and based on the comparison result that the second difference is greater than the second preset difference, it is determined to increase the glue filling pressure by the first pressure adjustment coefficient; based on the comparison result that the second difference is less than or equal to the second preset difference, it is determined to increase the glue filling pressure by the second pressure adjustment coefficient.

[0099] Specifically, the value range of the second preset difference is set to [0.3, 0.6], and 0.4 is preferred in the embodiment of the present invention; the value range of the first pressure adjustment coefficient is set to [1.14, 1.18], and 1.16 is preferred in the embodiment of the present invention; the value range of the second pressure adjustment coefficient is set to [1.06, 1.12], and 1.08 is preferred in the embodiment of the present invention.

[0100] Specifically, the adjustment process of the pressure adjustment coefficient is the same as the adjustment method of the temperature adjustment coefficient.

[0101] See also Figure 4 As shown, it is a schematic diagram of the structure of a capacitor for new energy vehicles according to an embodiment of the present invention.

[0102] The present invention also provides a capacitor prepared by using the method for preparing a capacitor for a new energy vehicle, comprising:

[0103] A plurality of capacitor cores 1 for storing electrical energy;

[0104] A heat sink 2, which is arranged between the capacitor cores 1 and is used to conduct the heat generated by the capacitor cores 1 to the outside of the capacitor;

[0105] The housing 3 is used to encapsulate the capacitor core 1 and the heat sink 2 .

[0106] So far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

Claims

1. A method for preparing a capacitor for new energy vehicles, characterized in that: include: Pre-treating the positive and negative welding surfaces of several capacitor cores to sequentially perform negative welding and positive welding, and installing a heat sink and a housing to form a semi-finished capacitor when welding is completed; A three-dimensional model is constructed based on the semi-finished capacitor to obtain the gap distribution information of the semi-finished capacitor, the semi-finished capacitor is divided into a plurality of regions with equal volume, the number of gaps with a gap width less than a preset width in any region is counted to determine the glue filling strategy, and the glue filling is completed to obtain the finished capacitor; Processing the infrared thermal imaging video of the finished product capacitor performance test process frame by frame to determine the grayscale change rate to determine the eligibility of the thermal conductivity efficiency; For finished capacitors with unqualified thermal conductivity, determine the distribution uniformity of the temperature concentration area to adjust the preset temperature / preset duration of the welding process, or adjust the glue filling pressure of the glue filling process; The finished capacitor is prepared according to the adjusted preparation process until the thermal conductivity efficiency is qualified; The process of determining a potting strategy based on the number of voids includes: Comparing the number of gaps with a preset number, and counting the number of regions where the number of gaps is greater than the preset number; comparing the area percentage of the number of areas to the total number of areas with a preset percentage; Determining the glue pouring strategy as regional glue pouring based on the comparison result that the regional percentage is greater than the preset percentage; Determining the glue pouring strategy as overall glue pouring based on the comparison result that the area percentage is less than or equal to the preset percentage; Under the condition of determining the glue filling in different regions, the number of gaps corresponding to each region is arranged in descending order, and glue filling is performed according to the arrangement result; The process of determining the eligibility of thermal conductivity based on the grayscale change rate includes: Comparing the grayscale change rate with a preset change rate; Determining that the thermal conductivity efficiency is unqualified based on a comparison result that the grayscale change rate is less than the preset change rate; For finished capacitors with unqualified thermal conductivity efficiency, the process of determining the cause of the unqualified thermal conductivity efficiency based on the distribution uniformity of the temperature concentration area includes: For the frame image corresponding to the maximum grayscale average value, a preset grayscale value is used as an edge, and an area with a grayscale value greater than the preset grayscale value is determined as a temperature concentration area; Counting the number of the temperature concentration areas in any region, and calculating the distribution variance based on the number; comparing the distribution variance with a preset variance; Determining, based on the comparison result that the distribution variance is less than the preset variance, that the reason why the thermal conductivity efficiency is unqualified is that the welding process is unqualified; Based on the comparison result that the distribution variance is greater than or equal to the preset variance, it is determined that the reason why the thermal conductivity efficiency is unqualified is that the glue filling process is unqualified.

2. The method for preparing a capacitor for new energy vehicles according to claim 1, characterized in that: The process of processing the infrared thermal imaging video frame by frame to determine the grayscale change rate includes: Extract each frame of the infrared thermal imaging video and perform grayscale processing to determine the grayscale average value; Determine the time difference between the frame image corresponding to the maximum grayscale average value and the frame image corresponding to the standard grayscale average value, and determine the grayscale difference between the maximum grayscale average value and the standard grayscale average value; Determine the ratio of the grayscale difference to the time difference as the grayscale change rate; Among them, a corresponding relationship between grayscale value and temperature is preset, and the standard grayscale average value is the grayscale average value corresponding to the normal working temperature of the finished capacitor.

3. The method for preparing a capacitor for new energy vehicles according to claim 2, characterized in that: Under the condition that the welding process is determined to be unqualified, the preset variance is subtracted from the distribution variance to obtain a first difference, and based on the comparison result that the first difference is greater than the first preset difference, it is determined to reduce the preset welding temperature by the temperature adjustment coefficient.

4. The method for preparing a capacitor for new energy vehicles according to claim 3, characterized in that: Based on the comparison result that the first difference is less than or equal to the first preset difference, it is determined to reduce the preset welding time by the time adjustment coefficient.

5. The method for preparing a capacitor for new energy vehicles according to claim 4, characterized in that: Under the condition that the glue filling process is determined to be unqualified, the distribution variance is subtracted from the preset variance to obtain a second difference, and based on the comparison result that the second difference is greater than the second preset difference, it is determined to increase the glue filling pressure by the first pressure adjustment coefficient; based on the comparison result that the second difference is less than or equal to the second preset difference, it is determined to increase the glue filling pressure by the second pressure adjustment coefficient.

6. A capacitor prepared according to the method for preparing a capacitor for new energy vehicles according to any one of claims 1 to 5, characterized in that: include: A plurality of capacitor cores for storing electrical energy; A heat sink is disposed between the capacitor cores to conduct the heat generated by the capacitor cores to the outside of the capacitor; A housing is used to encapsulate the capacitor core and the heat sink.

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