Method, apparatus, and electronic device for determining electrical insulation performance of battery pack

Abstract

The application provides a method and device for determining the electrical insulation performance of a battery pack and an electronic device. The method comprises detecting an ambient temperature corresponding to an environment in which the battery pack is located, determining a first air temperature and a second air temperature corresponding to the battery pack when the ambient temperature changes from a first ambient temperature to a second ambient temperature, determining a first moisture content and a second moisture content according to the first air temperature and the second air temperature respectively, determining the amount of condensation in the battery pack when the ambient temperature changes from the first ambient temperature to the second ambient temperature according to the first moisture content and the second moisture content, and determining the electrical insulation performance of the battery pack according to the amount of condensation. The application solves the technical problem in the prior art that the influence of the amount of condensation of the battery pack in a hygrothermal cycle on the electrical insulation gap is mainly verified through experiments and lacks relevant theories for prediction.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of battery pack performance, in particular to a method and device for determining the electrical insulation performance of a battery pack and an electronic device. BACKGROUND

[0002] The new national standard for automotive power batteries requires that the battery pack undergoes a wet heat cycle test to verify the impact of high humidity and high temperature changes on the battery pack during actual use. The new national standard requires that after the test, there should be no leakage, shell rupture, fire or explosion phenomenon, and the insulation resistance within 30 minutes after the test should be not less than 100Ω / V.

[0003] In the prior art, the electrical performance of the battery pack is only verified by the test, and there is a lack of relevant theory for predicting the electrical performance of the battery pack.

[0004] In view of the above problems in the prior art, no effective solution has been proposed so far. SUMMARY

[0005] The main purpose of the present application is to provide a method and device for determining the electrical insulation performance of a battery pack and an electronic device, to solve the technical problem in the prior art that the impact of the condensation amount of the battery pack in the wet heat cycle on the electrical insulation gap is mainly verified by the test, and there is a lack of relevant theory for prediction.

[0006] According to an aspect of an embodiment of the present application, a method for determining the electrical insulation performance of a battery pack is provided, comprising: detecting the ambient temperature corresponding to the environment in which the battery pack is located, and in the case where the ambient temperature changes from a first ambient temperature to a second ambient temperature, determining the first air temperature and the second air temperature corresponding to the battery pack, wherein the first air temperature is the temperature of the air in the battery pack at the first ambient temperature, and the second air temperature is the temperature of the air in the battery pack at the second ambient temperature; determining the first moisture content and the second moisture content according to the first air temperature and the second air temperature respectively, wherein the first moisture content is the moisture content of the air in the battery pack when the air temperature in the battery pack is the first air temperature, and the second moisture content is the moisture content of the air in the battery pack when the air temperature in the battery pack is the second air temperature; determining the condensation amount in the battery pack when the ambient temperature changes from the first ambient temperature to the second ambient temperature according to the first moisture content and the second moisture content; and determining the electrical insulation performance of the battery pack according to the condensation amount.

[0007] Further, in a case that the environment temperature is changed from the first environment temperature to the second environment temperature, the first air temperature and the second air temperature corresponding to the battery pack are determined, including: obtaining a first preset condition, and determining a first temperature change curve of the battery cell in a hygrothermal cycle period under the first preset condition, wherein the battery cell is a battery cell contained in the battery pack, the first preset condition is that the environment temperature is the first environment temperature, and an initial temperature of the battery cell is a first initial temperature; obtaining a second preset condition, and determining a second temperature change curve of the battery cell in the hygrothermal cycle period under the second preset condition, wherein the second preset condition is that the environment temperature is the second environment temperature, and the initial temperature of the battery cell is a second initial temperature; determining the first air temperature according to the first temperature change curve; and determining the second air temperature according to the second temperature change curve.

[0008] Further, the first air temperature is determined according to the first temperature change curve, including: reading a first battery cell temperature corresponding to a first time on the first temperature change curve, wherein the first time is a time corresponding to a first time period after an initial time; obtaining a third environment temperature corresponding to the first time; calculating a sum of the first battery cell temperature and the third environment temperature, and dividing the sum by 2 to obtain the first air temperature.

[0009] Further, the second air temperature is determined according to the second temperature change curve, including: reading a second battery cell temperature corresponding to a second time on the second temperature change curve, wherein the second time is a time corresponding to the first time period after the initial time; obtaining a fourth environment temperature corresponding to the second time; calculating a sum of the second battery cell temperature and the fourth environment temperature, and dividing the sum by 2 to obtain the second air temperature.

[0010] Further, the condensation amount in the battery pack when the environment temperature is changed from the first environment temperature to the second environment temperature is determined according to the first moisture content and the second moisture content, including: obtaining a low-pressure air intake rate corresponding to an environment temperature change process; obtaining an air mass in the battery pack; obtaining a condensation duration corresponding to the battery pack; and determining the condensation amount according to the low-pressure air intake rate, the air mass, the condensation duration, the first moisture content and the second moisture content.

[0011] Further, the electrical insulation performance of the battery pack is determined according to the condensation amount, including: obtaining a surface area corresponding to a metal component inside the battery pack; determining a water droplet volume corresponding to a water droplet formed inside the battery pack according to the condensation amount and the surface area; and determining the electrical insulation performance according to the water droplet volume.

[0012] Further, the electrical insulation performance of the battery pack is determined according to the water drop volume, including: determining a diameter of the water drop according to the water drop volume; obtaining a preset electrical clearance and a preset creepage distance; calculating a sum value of the preset electrical clearance and the preset creepage distance, and subtracting the diameter from the sum value to obtain a target value; determining that the electrical insulation performance of the battery pack is a target electrical insulation performance when the target value is greater than or equal to a preset threshold, and the target electrical insulation performance is an electrical insulation performance meeting a preset electrical grade.

[0013] According to another aspect of the embodiments of the present application, a device for determining an electrical insulation performance of a battery pack is also provided, including: a first determining unit configured to detect an ambient temperature corresponding to an environment in which the battery pack is located, and determine a first air temperature and a second air temperature corresponding to the battery pack when the ambient temperature changes from a first ambient temperature to a second ambient temperature, wherein the first air temperature is a temperature of air in the battery pack at the first ambient temperature, and the second air temperature is a temperature of air in the battery pack at the second ambient temperature; a second determining unit configured to determine a first moisture content and a second moisture content according to the first air temperature and the second air temperature, respectively, wherein the first moisture content is a moisture content of the air in the battery pack when the temperature of the air in the battery pack is the first air temperature, and the second moisture content is a moisture content of the air in the battery pack when the temperature of the air in the battery pack is the second air temperature; a third determining unit configured to determine a condensation amount in the battery pack when the ambient temperature changes from the first ambient temperature to the second ambient temperature according to the first moisture content and the second moisture content; and a fourth determining unit configured to determine the electrical insulation performance of the battery pack according to the condensation amount.

[0014] According to another aspect of the embodiments of the present application, a computer readable storage medium is also provided, including a stored program, wherein the program performs a method for determining an electrical insulation performance of a battery pack.

[0015] According to another aspect of the embodiments of the present application, a processor is also provided, configured to run a program, wherein the program performs a method for determining an electrical insulation performance of a battery pack.

[0016] According to another aspect of the embodiments of the present application, an electronic device is also provided, including: one or more processors, a memory, and one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the one or more processors, and the one or more programs include a method for determining an electrical insulation performance of a battery pack.

[0017] In the embodiment of the present application, by detecting the ambient temperature corresponding to the environment where the battery pack is located, in the case where the ambient temperature changes from the first ambient temperature to the second ambient temperature, the first air temperature and the second air temperature corresponding to the battery pack are determined, wherein the first air temperature is the temperature of the air in the battery pack at the first ambient temperature, and the second air temperature is the temperature of the air in the battery pack at the second ambient temperature; the first moisture content and the second moisture content are determined according to the first air temperature and the second air temperature respectively, wherein the first moisture content is the moisture content of the air in the battery pack when the air temperature in the battery pack is the first air temperature, and the second moisture content is the moisture content of the air in the battery pack when the air temperature in the battery pack is the second air temperature; the condensation amount in the battery pack when the ambient temperature changes from the first ambient temperature to the second ambient temperature is determined according to the first moisture content and the second moisture content; and the electrical insulation performance of the battery pack is determined according to the condensation amount, which solves the technical problem in the prior art that whether the condensation amount of the battery pack in the hygrothermal cycle will affect the electrical insulation gap is verified mainly by test, and lacks relevant theory for prediction. The technical effect of accurately predicting the electrical performance of the battery pack affected by the condensation amount in the battery pack is achieved. BRIEF DESCRIPTION OF DRAWINGS

[0018] The drawings accompanying the specification of the present application are used to provide further understanding of the present application, the illustrative embodiments of the present application and the description thereof are used to explain the present application, and do not constitute improper limitation on the present application. In the drawings:

[0019] Figure 1 is a flowchart of a method for determining the electrical insulation performance of a battery pack according to an embodiment of the present application; and

[0020] Figure 2 is a first temperature change curve schematic diagram provided by the embodiment of the present application;

[0021] Figure 3 is a second temperature change curve schematic diagram provided by the embodiment of the present application;

[0022] Figure 4 is a schematic diagram of the air temperature change curve and air temperature change in a hygrothermal cycle of a battery pack provided by the embodiment of the present application;

[0023] Figure 5 is a schematic diagram of the change of the moisture content in the battery pack when the battery pack experiences temperature reduction provided by the embodiment of the present application;

[0024] Figure 6 is a schematic diagram of a device for determining the electrical insulation performance of a battery pack according to an embodiment of the present application. DETAILED DESCRIPTION

[0025] It should be noted that the embodiments and features of the embodiments in the present application can be combined with each other in the case of no conflict. The technical solutions in the embodiments of the present application will be described in detail below with reference to the drawings and in combination with the embodiments.

[0026] In order for those skilled in the technical field to better understand the scheme of the present application, the technical solutions in the embodiments of the present application will be described clearly and completely below in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor should belong to the scope of protection of the present application.

[0027] It should be noted that the terms "first", "second" and the like in the specification and claims of the present application and the above-described drawings are used to distinguish similar objects, and do not necessarily indicate a specific order or a chronological sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the present application described herein can be implemented. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device including a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but can include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0028] It should be understood that when an element (such as a layer, film, region, or substrate) is described as "on" another element, it can be directly on the other element, or there can be an intermediate element. Also, in the specification and claims, when it is described that an element is "connected" to another element, the element can be "directly connected" to the other element, or "connected" to the other element through a third element.

[0029] As mentioned in the background, the prior art verifies whether the condensation of the battery pack in the hygrothermal cycle will affect the electrical insulation gap, mainly through test verification, lacking the related theory for the technical problem of pre-judgment. In order to solve the above problems, in a typical embodiment of the present application, a method and device for determining the electrical insulation performance of a battery pack and an electronic device are provided.

[0030] According to the embodiments of the present application, a method for determining the electrical insulation performance of a battery pack is provided.

[0031] Figure 1 is a flowchart of a method for determining the electrical insulation performance of a battery pack according to an embodiment of the present application. As shown in Figure 1 , the method comprises the following steps:

[0032] In step S101, the ambient temperature corresponding to the environment where the battery pack is located is detected, and in the case where the ambient temperature is changed from a first ambient temperature to a second ambient temperature, a first air temperature and a second air temperature corresponding to the battery pack are determined, wherein the first air temperature is the temperature of the air in the battery pack at the first ambient temperature, and the second air temperature is the temperature of the air in the battery pack at the second ambient temperature.

[0033] In step S102, the first moisture content and the second moisture content are determined according to the first air temperature and the second air temperature respectively, wherein the first moisture content is the moisture content of the air in the battery pack when the air temperature in the battery pack is the first air temperature, and the second moisture content is the moisture content of the air in the battery pack when the air temperature in the battery pack is the second air temperature.

[0034] In step S103, the condensation amount in the battery pack when the ambient temperature is changed from the first ambient temperature to the second ambient temperature is determined according to the first moisture content and the second moisture content.

[0035] In step S104, the electrical insulation performance of the battery pack is determined according to the condensation amount.

[0036] Therefore, by monitoring the change of the ambient temperature, the change of the air temperature in the battery pack when the ambient temperature changes is determined, the air humidity in the battery pack is determined by determining the temperature of the air in the battery pack, the moisture content in the battery pack is determined, and the condensation amount in the battery pack is determined according to the moisture content corresponding to the change of the environment, and the electrical performance of the battery pack is determined according to the condensation amount.

[0037] In an optional embodiment, in the case where the ambient temperature is changed from the first ambient temperature to the second ambient temperature, the first air temperature and the second air temperature corresponding to the battery pack are determined, including: obtaining a first preset condition, and determining a first temperature change curve of the battery cell in a hygrothermal cycle period under the first preset condition, wherein the battery cell is a battery cell contained in the battery pack, the first preset condition is that the ambient temperature is the first ambient temperature and the initial temperature of the battery cell is the first initial temperature; obtaining a second preset condition, and determining a second temperature change curve of the battery cell in the hygrothermal cycle period under the second preset condition, wherein the second preset condition is that the ambient temperature is the second ambient temperature and the initial temperature of the battery cell is the second initial temperature; determining the first air temperature according to the first temperature change curve; and determining the second air temperature according to the second temperature change curve.

[0038] Therefore, according to the temperature change curve in the hygrothermal cycle, the change curve of the air in the battery pack is calculated, and since the gas temperature in the battery pack can be considered as the arithmetic mean of the temperature of the battery cell and the ambient temperature, the temperature change of the air in the battery pack can be obtained by calculating the temperature change of the battery cell.

[0039] Specifically, through the test and data processing, the heat exchange coefficient between the battery cell and the external environment is h, and the temperature of the next second is calculated by the following formula:

[0040]

[0041] Where, T 拟合(i) is the theoretical calculation value of the battery cell temperature in the i-th second,

[0042] T 拟合(i-1) is the theoretical calculation value of the battery cell temperature in the i-1-th second;

[0043] When i = 1, T 拟合(i-1) = T0, that is, the initial temperature;

[0044] T f is the ambient temperature;

[0045] C 电芯 is the specific heat capacity of the battery cell, which is 1357 J / K / kg;

[0046] M 电芯 is the mass of the battery cell, which is 0.8 kg in an embodiment provided in the present application;

[0047] h is the heat dissipation coefficient, which is 0.05 W / K / cell.

[0048] In the above embodiment, preferably, the initial temperature of the battery pack under the first preset condition is 25℃, and the first ambient temperature is 60℃. The first temperature change curve can be determined by the above formula, and the specific curve is shown in Figure 2 , Figure 2 is a schematic diagram of the first temperature change curve.

[0049] In a specific application scenario, the second preset ambient temperature is 25℃, and the initial temperature of the battery pack is 37.8℃. The second temperature change curve can be determined by the above formula, and the schematic diagram of the second temperature change curve is shown in Figure 3 .

[0050] In an alternative embodiment, the first air temperature is determined according to the first temperature change curve, including: reading the first cell temperature corresponding to the first time on the first temperature change curve, wherein the first time is the time corresponding to the first time period after the initial time; obtaining the third ambient temperature corresponding to the first time; calculating the sum of the first cell temperature and the third ambient temperature, and dividing the sum by 2 to obtain the first air temperature. The second air temperature is determined according to the second temperature change curve, including: reading the second cell temperature corresponding to the second time on the second temperature change curve, wherein the second time is the time corresponding to the first time period after the initial time; obtaining the fourth ambient temperature corresponding to the second time; calculating the sum of the second cell temperature and the fourth ambient temperature, and dividing the sum by 2 to obtain the second air temperature. In this embodiment, the first time period is 2.75h (2h+0.75h, 9900s), that is, the first time is the 9900s, the cell temperature corresponding to the first time is 37.8℃, and at the same time, the ambient temperature at the first time is 65℃, therefore, the first air temperature corresponding to the first time is (37.8+65) / 2=51.4℃. The second time period is 2.25h (1.5h+0.75h, 8100s), that is, the second time is the time corresponding to the 8100s on the second temperature curve, the battery temperature at this time is 33.8℃, and at the same time, the ambient temperature is 25℃, the battery air temperature at this time is calculated as: (33.8+25) / 2=29.4℃.

[0051] Further, by determining the first temperature curve and the second temperature curve, the total change curve of the air temperature in the battery pack in a hygrothermal cycle can be obtained, and by corresponding the first time and the second time, the first moisture content in the battery pack corresponding to the first time and the second moisture content in the battery pack corresponding to the second time can be obtained. As shown in Figure 4 Figure 4 The figure shows the air temperature change curve and the air temperature change in the battery pack in a hygrothermal cycle.

[0052] In an alternative embodiment, the condensation amount in the battery pack is determined when the ambient temperature changes from the first ambient temperature to the second ambient temperature according to the first moisture content and the second moisture content, including: obtaining the low-pressure air intake rate corresponding to the ambient temperature change process; obtaining the air mass in the battery pack; obtaining the condensation duration corresponding to the battery pack; determining the condensation amount according to the low-pressure air intake rate, the air mass, the condensation duration, the first moisture content, and the second moisture content.

[0053] As described above, in this embodiment, the air temperature in the battery pack experiences a temperature reduction process during the process of converting the temperature in the battery pack from the first air temperature to the second air temperature, as shown in​Figure 5 As shown, Figure 5 A schematic diagram of the change of the battery pack moisture content during temperature reduction is provided in the embodiments of the present application. In the process, point M represents that the battery pack is at a first air temperature of 51.4°C, and the moisture content in the battery pack is 72.5 g / kg, and point N represents that the battery pack is at a second air temperature of 29.4°C, and the moisture content in the battery pack is 26.2 g / kg. In the process, Figure 5 Point O is a virtual point, and in the entire change process, the gas is to ensure that the moisture content is unchanged, and the gas state is from point M to point O. Since the relative humidity at point O is greater than 100%, the excess water vapor will be condensed and precipitated, and after condensation and precipitation, the gas state is point N.

[0054] Further, the condensation amount is calculated according to the following formula:

[0055] Condensation amount = (moisture content at point M - moisture content at point N) * air mass participating in condensation,

[0056] In a specific application scenario, the condensation amount = (72.5 g / kg - 26.2 g / kg) * (50L + 0.1L / min*2.25h) * 1.29kg / m3=3.79g,

[0057] Where 50L is the net volume of air in the battery pack;

[0058] 1.29kg / m3 is the density of air;

[0059] 0.1L / min: low pressure air inlet rate;

[0060] 2.25h: condensation time.

[0061] As described above, since the environmental relative humidity is 80%-98%, the amount of water vapor is very small, and the influence of evaporation is not considered.

[0062] It should be noted that according to the requirements of the national standard, the condensation amount of five wet heat cycles needs to be calculated, which is 3.79*5=18.95g.

[0063] In an optional embodiment, the electrical insulation performance of the battery pack is determined according to the amount of condensation, including: obtaining a surface area corresponding to a metal component inside the battery pack; determining a water droplet volume corresponding to a water droplet formed inside the battery pack according to the amount of condensation and the surface area; and determining the electrical insulation performance according to the water droplet volume. The electrical insulation performance is determined according to the water droplet volume, including: determining a diameter of the water droplet according to the water droplet volume; obtaining a preset electrical clearance and a preset creepage distance; calculating a sum of the preset electrical clearance and the preset creepage distance, and subtracting the diameter from the sum to obtain a target value; and determining that the electrical insulation performance of the battery pack is a target electrical insulation performance when the target value is greater than or equal to a preset threshold, and the target electrical insulation performance is an electrical insulation performance meeting a preset electrical grade.

[0064] In the above embodiment, the size of the water droplet of the amount of condensation in the test is only considered the condensation of the main metal components inside the battery pack, and it is assumed that the amount of condensation is uniformly distributed on the surface of the components. It is assumed that the amount of condensation of an area of 2500 mm 2 (i.e., 50x50 mm) can be combined to form a water droplet, and the size of the water droplet is calculated.

[0065] The preset threshold described above is the minimum design requirement required by the national standard. If the target value is greater than or equal to the minimum design requirement, the battery pack meets the insulation design requirement, that is, meets the preset electrical grade.

[0066] By the method for determining the electrical insulation performance of the battery pack provided in the present application, the air temperature change inside the battery pack under the wet heat cycle condition of the battery pack can be theoretically analyzed, so that the size of the amount of condensation of the battery pack under the wet heat cycle is calculated, and then the possible water droplet diameter is calculated according to the condensable area inside the battery pack, whether it will affect the electrical insulation is determined, and the grade of the electrical performance of the battery pack is determined.

[0067] It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and although the logical order is shown in the flowchart, in some cases, the steps shown or described herein can be executed in an order different from that shown herein.

[0068] The present application also provides a device for determining the electrical insulation performance of the battery pack. It should be noted that the device for determining the electrical insulation performance of the battery pack provided in the present application can be used to execute the method for determining the electrical insulation performance of the battery pack provided in the present application. The device for determining the electrical insulation performance of the battery pack provided in the present application is introduced as follows.

[0069] Figure 6 is a schematic diagram of a device for determining the electrical insulation performance of the battery pack according to an embodiment of the present application. As shown in Figure 6As shown, the device comprises: a first determination unit 601 configured to detect an ambient temperature corresponding to an environment where the battery pack is located, and determine a first air temperature and a second air temperature corresponding to the battery pack in a case where the ambient temperature changes from a first ambient temperature to a second ambient temperature, wherein the first air temperature is a temperature of air in the battery pack at the first ambient temperature, and the second air temperature is a temperature of air in the battery pack at the second ambient temperature; a second determination unit 602 configured to determine a first humidity content and a second humidity content according to the first air temperature and the second air temperature respectively, wherein the first humidity content is a humidity content of the air in the battery pack when the temperature of the air in the battery pack is the first air temperature, and the second humidity content is a humidity content of the air in the battery pack when the temperature of the air in the battery pack is the second air temperature; a third determination unit 603 configured to determine a condensation amount in the battery pack when the ambient temperature changes from the first ambient temperature to the second ambient temperature according to the first humidity content and the second humidity content; and a fourth determination unit 604 configured to determine an electrical insulation performance of the battery pack according to the condensation amount.

[0070] Optionally, the first determination unit 601 comprises: a first determination subunit configured to obtain a first preset condition and determine a first temperature change curve of a battery cell in a hygrothermal cycle period under the first preset condition, wherein the battery cell is a battery cell contained in the battery pack, the first preset condition is that the ambient temperature is the first ambient temperature and the initial temperature of the battery cell is a first initial temperature; a second determination subunit configured to obtain a second preset condition and determine a second temperature change curve of the battery cell in the hygrothermal cycle period under the second preset condition, wherein the second preset condition is that the ambient temperature is the second ambient temperature and the initial temperature of the battery cell is a second initial temperature; and a third determination subunit configured to determine the first air temperature according to the first temperature change curve, and a fourth determination subunit configured to determine the second air temperature according to the second temperature change curve.

[0071] Optionally, the third determination subunit comprises: a first reading module configured to read a first battery cell temperature corresponding to a first time on the first temperature change curve, wherein the first time is a time corresponding to a first time period after an initial time; a first acquisition module configured to acquire a third ambient temperature corresponding to the first time; and a first calculation module configured to calculate a sum of the first battery cell temperature and the third ambient temperature, and divide the sum by 2 to obtain the first air temperature.

[0072] Optionally, the fourth determination subunit comprises: a second reading module configured to read a second battery cell temperature corresponding to a second time on the second temperature change curve, wherein the second time is a time corresponding to the first time period after the initial time; a second acquisition module configured to acquire a fourth ambient temperature corresponding to the second time; and a second calculation module configured to calculate a sum of the second battery cell temperature and the fourth ambient temperature, and divide the sum by 2 to obtain the second air temperature.

[0073] Optionally, the third determining unit 603 comprises: a first obtaining sub-unit, configured to obtain a low-pressure air intake rate corresponding to an ambient temperature change process; a second obtaining sub-unit, configured to obtain an air mass in the battery pack; a third obtaining sub-unit, configured to obtain a dewing duration corresponding to the battery pack; and a fifth determining sub-unit, configured to determine the dewing amount according to the low-pressure air intake rate, the air mass, the dewing duration, the first moisture content and the second moisture content.

[0074] Optionally, according to the dewing amount, the fourth determining unit 604 comprises: a fourth obtaining sub-unit, configured to obtain a surface area of a metal component inside the battery pack; a sixth determining sub-unit, configured to determine a water droplet volume of a water droplet formed inside the battery pack according to the dewing amount and the surface area; and a seventh determining sub-unit, configured to determine the electrical insulation performance according to the water droplet volume.

[0075] Optionally, the seventh determining sub-unit comprises: a first determining module, configured to determine a diameter of the water droplet according to the water droplet volume; a third obtaining module, configured to obtain a preset electrical clearance and a preset creepage distance; a third calculating module, configured to calculate a sum of the preset electrical clearance and the preset creepage distance, subtract the diameter from the sum to obtain a target value; and a second determining module, configured to compare the target value with a preset threshold, and determine that the electrical insulation performance of the battery pack is a target electrical insulation performance when the target value is greater than or equal to the preset threshold, the target electrical insulation performance being an electrical insulation performance meeting a preset electrical grade.

[0076] A device for determining electrical insulation performance of a battery pack comprises a processor and a memory, wherein the first determining unit 601 and the like are stored in the memory as program units, and the corresponding functions are realized by the processor executing the program units stored in the memory.

[0077] The processor comprises a core, and the core retrieves the corresponding program units from the memory. The core can be set to one or more, and the technical problem that whether the dewing amount of the battery pack in the hygrothermal cycle will affect the electrical insulation clearance is solved by adjusting the core parameters, mainly through experimental verification, and lacks relevant theories for prediction.

[0078] The memory can include a non-persistent memory in a computer readable medium, a random access memory (RAM) and / or a non-volatile memory such as a read-only memory (ROM) or a flash memory (flash RAM), and the memory comprises at least one memory chip.

[0079] The embodiment of the present application provides a computer readable storage medium, which stores a program, and the program is executed by a processor to realize a method for determining electrical insulation performance of a battery pack.

[0080] The embodiment of the present application provides a processor, which is used for running a program, wherein the processor executes a method for determining the electrical insulation performance of a battery pack when the program is running.

[0081] The embodiment of the present application provides a device, which comprises a processor, a memory and a program stored in the memory and capable of running on the processor, and the processor implements at least the following steps when executing the program: detecting an ambient temperature corresponding to an environment in which a battery pack is located, determining a first air temperature and a second air temperature corresponding to the battery pack in the case that the ambient temperature is changed from a first ambient temperature to a second ambient temperature, wherein the first air temperature is the temperature of air in the battery pack at the first ambient temperature, and the second air temperature is the temperature of air in the battery pack at the second ambient temperature; determining a first moisture content and a second moisture content according to the first air temperature and the second air temperature respectively, wherein the first moisture content is the moisture content of the air in the battery pack when the temperature of the air in the battery pack is the first air temperature, and the second moisture content is the moisture content of the air in the battery pack when the temperature of the air in the battery pack is the second air temperature; determining the amount of condensation in the battery pack when the ambient temperature is changed from the first ambient temperature to the second ambient temperature according to the first moisture content and the second moisture content; and determining the electrical insulation performance of the battery pack according to the amount of condensation.

[0082] Optionally, in the case that the ambient temperature is changed from the first ambient temperature to the second ambient temperature, the first air temperature and the second air temperature corresponding to the battery pack are determined, comprising: obtaining a first preset condition and determining a first temperature change curve corresponding to a battery cell in a hygrothermal cycle period under the first preset condition, wherein the battery cell is a battery cell contained in the battery pack, the first preset condition is that the ambient temperature is the first ambient temperature and the initial temperature of the battery cell is a first initial temperature; obtaining a second preset condition and determining a second temperature change curve corresponding to the battery cell in the hygrothermal cycle period under the second preset condition, wherein the second preset condition is that the ambient temperature is the second ambient temperature and the initial temperature of the battery cell is a second initial temperature; determining the first air temperature according to the first temperature change curve; and determining the second air temperature according to the second temperature change curve.

[0083] Optionally, the first air temperature is determined according to the first temperature change curve, comprising: reading a first battery cell temperature corresponding to a first time on the first temperature change curve, wherein the first time is a time corresponding to a first time period after an initial time; obtaining a third ambient temperature corresponding to the first time; calculating the sum of the first battery cell temperature and the third ambient temperature, and dividing the sum by 2 to obtain the first air temperature.

[0084] Optionally, the second air temperature is determined according to the second temperature change curve, including: reading a second battery cell temperature corresponding to a second time on the second temperature change curve, wherein the second time is a time corresponding to a first time period after the initial time; obtaining a fourth ambient temperature corresponding to the second time; calculating a sum of the second battery cell temperature and the fourth ambient temperature, and dividing the sum by 2 to obtain the second air temperature.

[0085] Optionally, the amount of condensation in the battery pack is determined when the ambient temperature changes from the first ambient temperature to the second ambient temperature according to the first moisture content and the second moisture content, including: obtaining a low-pressure air intake rate corresponding to the ambient temperature change process; obtaining an air mass in the battery pack; obtaining a condensation duration corresponding to the battery pack; determining the amount of condensation according to the low-pressure air intake rate, the air mass, the condensation duration, the first moisture content, and the second moisture content.

[0086] Optionally, the electrical insulation performance of the battery pack is determined according to the amount of condensation, including: obtaining a surface area corresponding to a metal component inside the battery pack; determining a water droplet volume corresponding to a water droplet formed inside the battery pack according to the amount of condensation and the surface area; and determining the electrical insulation performance according to the water droplet volume.

[0087] Optionally, the electrical insulation performance is determined according to the water droplet volume, including: determining a diameter of the water droplet according to the water droplet volume; obtaining a preset electrical clearance and a preset creepage distance; calculating a sum of the preset electrical clearance and the preset creepage distance, and subtracting the diameter from the sum to obtain a target value; determining that the target value is compared with a preset threshold, and in a case where the target value is greater than or equal to the preset threshold, determining that the electrical insulation performance of the battery pack is a target electrical insulation performance, and the target electrical insulation performance is an electrical insulation performance meeting a preset electrical grade. The device in this paper can be a server, a PC, a PAD, a mobile phone, etc.

[0088] The application further provides a computer program product, which is adapted to execute a program comprising the following method steps when executed on a data processing device: detecting an ambient temperature corresponding to an environment in which a battery pack is located; determining a first air temperature and a second air temperature corresponding to the battery pack in a case where the ambient temperature changes from a first ambient temperature to a second ambient temperature, wherein the first air temperature is a temperature of air in the battery pack at the first ambient temperature, and the second air temperature is a temperature of air in the battery pack at the second ambient temperature; determining a first moisture content and a second moisture content according to the first air temperature and the second air temperature respectively, wherein the first moisture content is a moisture content of the air in the battery pack when the temperature of the air in the battery pack is the first air temperature, and the second moisture content is a moisture content of the air in the battery pack when the temperature of the air in the battery pack is the second air temperature; determining a condensation amount in the battery pack when the ambient temperature changes from the first ambient temperature to the second ambient temperature according to the first moisture content and the second moisture content; and determining an electrical insulation performance of the battery pack according to the condensation amount.

[0089] Optionally, in the case where the ambient temperature changes from the first ambient temperature to the second ambient temperature, the first air temperature and the second air temperature corresponding to the battery pack are determined by: obtaining a first preset condition and determining a first temperature change curve of the battery cell in a hygrothermal cycle period under the first preset condition, wherein the battery cell is a battery cell contained in the battery pack, the first preset condition is that the ambient temperature is the first ambient temperature and an initial temperature of the battery cell is a first initial temperature; obtaining a second preset condition and determining a second temperature change curve of the battery cell in the hygrothermal cycle period under the second preset condition, wherein the second preset condition is that the ambient temperature is the second ambient temperature and the initial temperature of the battery cell is a second initial temperature; determining the first air temperature according to the first temperature change curve; and determining the second air temperature according to the second temperature change curve.

[0090] Optionally, the first air temperature is determined according to the first temperature change curve by: reading a first battery cell temperature corresponding to a first time on the first temperature change curve, wherein the first time is a time corresponding to a first time period after an initial time; obtaining a third ambient temperature corresponding to the first time; calculating a sum of the first battery cell temperature and the third ambient temperature, and dividing the sum by 2 to obtain the first air temperature.

[0091] Optionally, the second air temperature is determined according to the second temperature change curve by: reading a second battery cell temperature corresponding to a second time on the second temperature change curve, wherein the second time is a time corresponding to the first time period after the initial time; obtaining a fourth ambient temperature corresponding to the second time; calculating a sum of the second battery cell temperature and the fourth ambient temperature, and dividing the sum by 2 to obtain the second air temperature.

[0092] Optionally, the amount of condensation in the battery pack when the ambient temperature changes from the first ambient temperature to the second ambient temperature is determined according to the first moisture content and the second moisture content, including: obtaining a low-pressure air intake rate corresponding to the ambient temperature change process; obtaining the air mass in the battery pack; obtaining a condensation duration corresponding to the battery pack; and determining the amount of condensation according to the low-pressure air intake rate, the air mass, the condensation duration, the first moisture content, and the second moisture content.

[0093] Optionally, the electrical insulation performance of the battery pack is determined according to the amount of condensation, including: obtaining a surface area corresponding to a metal component inside the battery pack; determining a water droplet volume corresponding to a water droplet formed inside the battery pack according to the amount of condensation and the surface area; and determining the electrical insulation performance according to the water droplet volume.

[0094] Optionally, the electrical insulation performance is determined according to the water droplet volume, including: determining a diameter of the water droplet according to the water droplet volume; obtaining a preset electrical clearance and a preset creepage distance; calculating a sum of the preset electrical clearance and the preset creepage distance, and subtracting the diameter from the sum to obtain a target value; and determining that the electrical insulation performance of the battery pack is a target electrical insulation performance when the target value is greater than or equal to a preset threshold, the target electrical insulation performance being an electrical insulation performance meeting a preset electrical grade.

[0095] In the above embodiments of the present application, the description of each embodiment focuses on different aspects, and the parts not described in detail in a certain embodiment can be referred to the relevant description of other embodiments.

[0096] In several embodiments provided in the present application, it should be understood that the disclosed technical contents can be implemented by other ways. Among them, the device embodiments described above are only schematic, for example, the division of units can be a logical function division, and actual implementation can have another division way, for example, a plurality of units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the units or modules shown or discussed can be indirect coupling or communication connection through some interfaces, units or modules, which can be electrical or other forms.

[0097] The units described as separate components can or can not be physically separated, and the components shown as units can or can not be physical units, that is, they can be located in one place or distributed on multiple units. According to actual needs, part or all of the units can be selected to achieve the purpose of the present embodiment scheme.

[0098] In addition, each function unit in each embodiment of the present application can be integrated in one processing unit, or each unit can be physically present separately, or two or more units can be integrated in one unit. The integrated unit can be realized in the form of hardware or in the form of a software function unit.

[0099] If the integrated unit is realized in the form of a software function unit and sold or used as an independent product, it can be stored in a computer readable storage medium. Based on such understanding, the technical solutions of the present application, essentially or in part, or all or part of the technical solutions can be embodied in the form of a software product. The computer software product is stored in a storage medium, and includes several instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods in the various embodiments of the present application. The foregoing storage medium includes: U disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), mobile hard disk, magnetic disk or optical disk, and various program codes that can store the medium.

[0100] From the above description, it can be seen that the above-mentioned embodiments of the present application achieve the following technical effects:

[0101] 1) A set of calculation methods for condensation amount in the wet heat cycle process of the battery pack and a method for judging the electrical performance of the battery pack are provided. The test results can be roughly judged by theoretical calculation, thereby avoiding test dependence.

[0102] The above is only a preferred embodiment of the present application and is not used to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A method for determining the electrical insulation performance of a battery pack, characterized in that, include: The ambient temperature corresponding to the environment where the battery pack is located is detected. When the ambient temperature changes from a first ambient temperature to a second ambient temperature, the first air temperature and the second air temperature corresponding to the battery pack are determined. The first air temperature is the temperature of the air inside the battery pack at the first ambient temperature, and the second air temperature is the temperature of the air inside the battery pack at the second ambient temperature. A first humidity content and a second humidity content are determined based on the first air temperature and the second air temperature, respectively. The first humidity content is the humidity content of the air in the battery pack when the air temperature inside the battery pack is the first air temperature, and the second humidity content is the humidity content of the air in the battery pack when the air temperature inside the battery pack is the second air temperature. Based on the first moisture content and the second moisture content, determine the amount of condensation inside the battery pack when the ambient temperature changes from the first ambient temperature to the second ambient temperature; The electrical insulation performance of the battery pack is determined based on the condensation level.

2. The method according to claim 1, characterized in that, When the ambient temperature changes from a first ambient temperature to a second ambient temperature, determining the first air temperature and the second air temperature corresponding to the battery pack includes: Obtain a first preset condition and determine a first temperature change curve of the battery cell within a wet and hot cycle under the first preset condition, wherein the battery cell is the battery cell contained in the battery pack, the first preset condition is that the ambient temperature is the first ambient temperature, and the initial temperature of the battery cell is the first initial temperature. Obtain a second preset condition and determine a second temperature change curve of the battery cell within a damp heat cycle under the second preset condition, wherein the second preset condition is that the ambient temperature is the second ambient temperature and the initial temperature of the battery cell is the second initial temperature; The first air temperature is determined based on the first temperature change curve. The second air temperature is determined based on the second temperature change curve.

3. The method according to claim 2, characterized in that, Determining the first air temperature based on the first temperature change curve includes: Read the temperature of the first cell at the first moment on the first temperature change curve, wherein the first moment is the moment after the first time interval from the initial moment; Obtain the third ambient temperature corresponding to the first moment; Calculate the sum of the first cell temperature and the third ambient temperature, and divide the sum by 2 to obtain the first air temperature.

4. The method according to claim 2, characterized in that, Based on the second temperature change curve, the second air temperature is determined, including: Read the temperature of the second cell at the second moment on the second temperature change curve, wherein the second moment is the moment after the first time period from the initial moment; Obtain the fourth ambient temperature corresponding to the second time point; Calculate the sum of the second cell temperature and the fourth ambient temperature, and divide the sum by 2 to obtain the second air temperature.

5. The method according to claim 1, characterized in that, Based on the first moisture content and the second moisture content, the condensation level inside the battery pack is determined when the ambient temperature changes from the first ambient temperature to the second ambient temperature, including: Obtain the low-pressure intake rate corresponding to the ambient temperature change process; Obtain the air quality inside the battery pack; Obtain the condensation duration corresponding to the battery pack; The amount of condensation is determined based on the low-pressure intake rate, the air quality, the condensation time, the first moisture content, and the second moisture content.

6. The method according to claim 1, characterized in that, Based on the condensation level, the electrical insulation performance of the battery pack is determined, including: Obtain the surface area corresponding to the metal components inside the battery pack; Based on the condensation amount and the surface area, determine the volume of the water droplets formed inside the battery pack. The electrical insulation performance is determined based on the volume of the water droplet.

7. The method according to claim 6, characterized in that, Based on the volume of the water droplet, the electrical insulation performance is determined, including: The diameter of the water droplet is determined based on its volume. Obtain the preset electrical clearance and preset creepage distance; Calculate the sum of the preset electrical clearance and the preset creepage distance, and subtract the diameter from the sum to obtain the target value; The target value is compared with a preset threshold, and if the target value is greater than or equal to the preset threshold, the electrical insulation performance of the battery pack is determined to be the target electrical insulation performance, which is the electrical insulation performance that meets the preset electrical level.

8. An apparatus for determining the electrical insulation performance of a battery pack, characterized in that, include: The first determining unit is used to detect the ambient temperature corresponding to the environment where the battery pack is located. When the ambient temperature changes from the first ambient temperature to the second ambient temperature, it determines the first air temperature and the second air temperature corresponding to the battery pack. The first air temperature is the temperature of the air inside the battery pack at the first ambient temperature, and the second air temperature is the temperature of the air inside the battery pack at the second ambient temperature. The second determining unit is used to determine a first moisture content and a second moisture content based on the first air temperature and the second air temperature, respectively, wherein the first moisture content is the moisture content of the air in the battery pack when the air temperature in the battery pack is the first air temperature, and the second moisture content is the moisture content of the air in the battery pack when the air temperature in the battery pack is the second air temperature. The third determining unit is used to determine the amount of condensation in the battery pack when the ambient temperature changes from the first ambient temperature to the second ambient temperature, based on the first moisture content and the second moisture content. The fourth determining unit is used to determine the electrical insulation performance of the battery pack based on the condensation amount.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium includes a stored program, wherein the program executes a method for determining the electrical insulation properties of a battery pack as described in any one of claims 1 to 7.

10. A processor, characterized in that, The processor is used to run a program, wherein the program executes a method for determining the electrical insulation performance of a battery pack as described in any one of claims 1 to 7.

11. An electronic device, characterized in that, include: One or more processors, a memory, and one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the one or more processors, the one or more programs including a method for performing a method for determining the electrical insulation performance of a battery pack as described in any one of claims 1 to 7.

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