Power battery monitoring method, device and vehicle

Abstract

This application provides a power battery monitoring method, device, and vehicle for detecting air tightness, condensation, and water ingress in power batteries. The power battery monitoring method includes: after the vehicle is powered on, determining whether the explosion-proof valve is currently performing an air pressure balancing action; if the explosion-proof valve is not currently performing an air pressure balancing action, obtaining an absolute humidity reference value, the relative humidity within the battery pack, and the wall temperature; determining the absolute humidity, dew point temperature, and theoretical absolute humidity in the current environment based on the relative humidity within the battery pack and the wall temperature; performing air tightness, condensation, and water ingress detection on the battery pack based on the relative relationship between the wall temperature and the dew point temperature, the relative relationship between the absolute humidity and the absolute humidity reference value, and the relative relationship between the absolute humidity and the theoretical absolute humidity; and performing abnormality handling if at least one of the air tightness, condensation, or water ingress detection results is abnormal.

Description

Technical Field

[0001] The present invention relates to the field of new energy vehicle power battery safety technology, and more specifically to a power battery monitoring method, device and vehicle. Background Art

[0002] With the rapid development of China's new energy vehicle industry, which is playing an increasingly important role in the global market, consumers have higher expectations for the safety performance of new energy vehicles. As a core component of new energy vehicles, power battery safety and full lifecycle safety monitoring are gradually becoming the primary considerations for consumers when purchasing a vehicle. The safe use of power batteries throughout their lifecycle is directly affected by the humidity and airtightness of the operating environment, making humidity and airtightness testing of power batteries particularly important.

[0003] During operation, power batteries usually need to maintain a high degree of airtightness to ensure their performance and safety. Once the airtightness fails, moisture, dust or other impurities in the external environment will enter the battery, causing serious damage to the battery's performance and safety. The following are the main hazards of airtightness failure to power batteries: (1) Moisture intrusion causes battery performance degradation, which is reflected in changes in electrolyte performance, battery capacity reduction, and internal resistance increase; (2) External impurities entering cause safety hazards, mainly reflected in short circuit risks, corrosion risks, and thermal runaway risks; (3) Airtightness failure leads to unstable pressure, mainly reflected in gas leakage and battery expansion; (4) Affects the cycle life of the battery, mainly reflected in accelerated aging and single cell consistency problems. Summary of the Invention

[0004] The present application provides a power battery monitoring method, device and vehicle for detecting the air tightness, condensation and water ingress of the power battery.

[0005] The technical solution of this application is:

[0006] This application provides a power battery monitoring method, including:

[0007] After the vehicle is powered on, determine whether the explosion-proof valve is currently performing the air pressure balancing action;

[0008] If the explosion-proof valve is not currently performing an air pressure balancing action, obtain the absolute humidity reference value, the relative humidity inside the battery pack, and the wall temperature;

[0009] Determine the absolute humidity, dew point temperature, and theoretical absolute humidity in the current environment based on the relative humidity and wall temperature inside the battery pack;

[0010] Performing air tightness, condensation, and water ingress testing on the battery pack based on the relative relationship between the wall temperature and the dew point temperature, the relative relationship between the absolute humidity and the absolute humidity reference value, and the relative relationship between the absolute humidity and the theoretical absolute humidity;

[0011] If at least one of the battery pack's air tightness, condensation, and water ingress test results is abnormal, perform abnormal processing.

[0012] Preferably, the method further comprises:

[0013] Before the vehicle is powered off, the relative humidity and wall temperature inside the battery pack are uploaded to the cloud;

[0014] After being awakened by the cloud due to the identification of condensation risk in the battery pack, the system determines whether the battery pack meets the heating conditions based on the battery pack heating instructions sent by the cloud;

[0015] If the battery pack meets the heating conditions, the battery pack is heated until the wall temperature of the battery pack reaches the dew point temperature, after which the system enters a dormant state. The dew point temperature is determined by the cloud based on the relative humidity and wall temperature of the battery pack uploaded before the vehicle is powered off.

[0016] If the battery pack does not meet the heating conditions, it will enter a dormant state after feeding back to the cloud that the battery pack does not meet the heating conditions, and will update the environmental data in the battery pack the next time it is awakened by the cloud because the real-time ambient temperature is lower than the dew point temperature.

[0017] Preferably, the step of performing air tightness, condensation, and water ingress detection on the battery pack according to the relative relationship between the wall temperature and the dew point temperature, the relative relationship between the absolute humidity and the absolute humidity reference value, and the relative relationship between the absolute humidity and the theoretical absolute humidity includes:

[0018] When the wall temperature Tn is less than or equal to the dew point temperature T0, if the absolute humidity AHn1 is less than the minimum value of the first humidity interval formed by the absolute humidity reference value AH0, the battery pack is heated; after a preset heating time, water ingress or condensation in the battery pack is identified based on the re-acquired relative humidity RHn';

[0019] When it is determined that water has entered the battery pack or condensation has occurred, the new absolute humidity AHn1' and the new theoretical absolute humidity AHn2' in the current environment are re-determined based on the re-acquired relative humidity RHn' and wall temperature Tn', and the air tightness of the battery pack is identified based on the relative size of the new absolute humidity AHn1' and the second humidity interval formed by the new theoretical absolute humidity AHn2'.

[0020] Preferably, the step of identifying water ingress or condensation in the battery pack according to the re-acquired relative humidity RHn includes:

[0021] If the difference between the relative humidity RHn before the battery pack is heated and the re-obtained relative humidity RHn' is greater than a preset threshold, it is determined that condensation has occurred in the battery pack;

[0022] If the difference between the relative humidity RHn before the battery pack is heated and the re-acquired relative humidity RHn' is less than or equal to a preset threshold, it is determined that water has entered the battery pack.

[0023] Preferably, the step of identifying the airtightness of the battery pack according to the relative size of the new absolute humidity AHn1′ and the second humidity interval formed by the new theoretical absolute humidity AHn2′ includes:

[0024] If the new absolute humidity AHn1' is within the second humidity interval formed by the new theoretical absolute humidity AHn2', it is determined that the battery pack is airtight.

[0025] If the new absolute humidity AHn1 ′ is not within the second humidity interval formed by the new theoretical absolute humidity AHn2 ′, it is determined that the airtightness of the battery pack has failed.

[0026] Preferably, the step of performing air tightness, condensation, and water ingress detection on the battery pack according to the relative relationship between the wall temperature and the dew point temperature, the relative relationship between the absolute humidity and the absolute humidity reference value, and the relative relationship between the absolute humidity and the theoretical absolute humidity further includes:

[0027] When the wall surface temperature Tn is greater than the dew point temperature T0, the airtightness of the battery pack is identified based on the relative magnitude relationship between the absolute humidity AHn and a third humidity range formed by the absolute humidity reference value AH0.

[0028] Preferably, the step of identifying the airtightness of the battery pack according to the relative magnitude relationship between the absolute humidity AHn and a third humidity interval formed by the absolute humidity reference value AH0 includes:

[0029] If the absolute humidity AHn is within a third humidity interval formed by the absolute humidity reference value AH0, it is determined that the airtightness of the battery pack is normal;

[0030] If the absolute humidity AHn is not within the third humidity range formed by the absolute humidity reference value AH0, it is determined that the airtightness of the battery pack has failed.

[0031] Preferably, the battery pack is heated by controlling a humidity sensor with a heating function provided in the battery pack.

[0032] Preferably, the method further comprises:

[0033] If the explosion-proof valve is currently performing an air pressure balancing action, obtain the relative humidity, wall temperature, and real-time pressure inside the battery pack;

[0034] If the relative humidity, wall temperature and real-time pressure inside the battery pack remain balanced within a predetermined period of time, the absolute humidity in the current environment is determined based on the relative humidity and wall temperature inside the battery pack that are re-obtained after balance, and the absolute humidity is updated to a new absolute humidity reference value.

[0035] Preferably, if at least one of the air tightness, condensation, and water ingress detection results of the battery pack is abnormal, the steps of handling the abnormality include:

[0036] If only condensation anomaly exists, and the vehicle's insulation resistance value is not less than the predetermined normal value for a long time, a first prompt is output to remind the user to replace the battery pack's moisture absorbent sheet;

[0037] If only condensation anomalies exist and the vehicle's insulation resistance remains within the preset insulation resistance range for a long period of time, a second prompt will be output to remind the user that there is an insulation risk in the vehicle and that the battery pack's moisture absorbent sheet needs to be replaced and the airtightness repaired.

[0038] If only the airtightness is abnormal, a third prompt is output to remind the user to have the vehicle inspected and to avoid driving on flooded roads and in rainy weather.

[0039] If there is abnormal condensation and the battery pack has an insulation failure, or water has entered the battery pack, the vehicle's use will be restricted, the battery high voltage will be cut off, and charging and discharging will be prohibited. The battery fault warning light on the instrument panel will be illuminated.

[0040] This application also provides a power battery monitoring method, which is applied to the cloud, and the method includes:

[0041] Obtain the relative humidity and wall temperature inside the battery pack uploaded by the vehicle before power is turned off;

[0042] Obtain the ambient temperature forecast for the vehicle's location;

[0043] Determine the dew point temperature based on the relative humidity and wall temperature inside the battery pack;

[0044] If the relative humidity is greater than a preset humidity and the ambient forecast temperature is less than the maximum value of the temperature range formed by the dew point temperature, the vehicle is awakened, a condensation risk warning is sent to the vehicle, and a control instruction for heating the battery pack is sent to the vehicle;

[0045] If the battery pack does not meet the heating conditions as reported by the vehicle, the vehicle is awakened to update the environmental data in the battery pack when the real-time ambient temperature is lower than the dew point temperature.

[0046] The present application also provides a power battery monitoring device, comprising:

[0047] A first acquisition module is used to obtain the current absolute humidity reference value of the vehicle;

[0048] A real-time parameter acquisition module is used to obtain the relative humidity and wall temperature inside the battery pack if the explosion-proof valve is not currently performing pressure balancing.

[0049] The parameter estimation module is used to determine the absolute humidity, dew point temperature and theoretical absolute humidity in the current environment based on the relative humidity and wall temperature in the battery pack;

[0050] a detection module, configured to perform air tightness, condensation, and water ingress detection of the battery pack based on a relative relationship between the wall temperature and the dew point temperature, a relative relationship between the absolute humidity and the absolute humidity reference value, and a relative relationship between the absolute humidity and the theoretical absolute humidity;

[0051] The processing module is used to perform abnormal processing if there is at least one abnormality in the air tightness, condensation and water ingress detection results of the battery pack.

[0052] The present application also provides a vehicle, comprising the above-mentioned power battery monitoring device.

[0053] The beneficial effects of the present invention are:

[0054] The absolute humidity, dew point temperature, and theoretical absolute humidity in the current environment are accurately determined by measuring the relative humidity inside the battery pack and the wall humidity. Based on these parameters, the actual operating status of the battery pack can be accurately monitored in real time, effectively preventing and responding to various hazards caused by abnormalities such as condensation, airtightness failure, and water ingress in the battery pack. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] Figure 1 This is a flow chart of the power battery monitoring method in Example 1 of the present application;

[0056] Figure 2 This is a flow chart of step S104 in the first embodiment of the present application;

[0057] Figure 3 This is a flow chart of a power battery monitoring method applied in the cloud in the second embodiment of the present application;

[0058] Figure 4 This is a flow chart of the power battery monitoring device in Example 3 of the present application. DETAILED DESCRIPTION

[0059] The present invention is further described below with reference to the following embodiments and accompanying drawings. This embodiment is based on the technical solution of the present invention and provides a detailed implementation method and specific operation process, but the scope of protection of the present invention is not limited to the following embodiments.

[0060] Reference Figure 1 , Embodiment 1 of the present application provides a power battery monitoring method, including:

[0061] S101, after the vehicle is powered on, determine whether the explosion-proof valve is currently performing an air pressure balancing action;

[0062] S102, if the explosion-proof valve is not currently performing an air pressure balancing action, obtain an absolute humidity reference value, a relative humidity in the battery pack, and a wall temperature;

[0063] S103, determining the absolute humidity, dew point temperature, and theoretical absolute humidity of each unit in the current environment based on the relative humidity in the battery pack and the wall temperature;

[0064] S104: Performing air tightness, condensation, and water ingress testing on the battery pack based on the relative relationship between the wall temperature and the dew point temperature, the relative relationship between the absolute humidity and the absolute humidity reference value, and the relative relationship between the absolute humidity and the theoretical absolute humidity.

[0065] S105: If at least one of the air tightness, condensation, and water ingress detection results of the battery pack is abnormal, perform abnormal processing.

[0066] The application object of the power battery monitoring method in the first embodiment of the present application is an on-board controller, such as a vehicle controller, a battery management system, etc. The application scenario of this method is to be performed after the vehicle is powered on.

[0067] In step S101 , it is determined whether the explosion-proof valve is currently performing an air pressure balancing action, which is determined based on the real-time pressure inside the battery pack and the real-time pressure outside the battery pack.

[0068] The specific structural form of the explosion-proof valve does not belong to the improvement point of this application. The existing explosion-proof valve structure in the field can be adopted and is not limited in the embodiments of this application.

[0069] Among them, when the real-time pressure P inside the battery pack is equal to the ambient pressure P outside the battery pack ’When the difference between the ambient pressure P' outside the battery pack and the real-time pressure P inside the battery pack is greater than or equal to the preset first explosion-proof opening pressure differential, the explosion-proof valve will release pressure until the pressure differential falls below the first explosion-proof opening pressure differential, at which point the valve closes. Furthermore, when the difference between the ambient pressure P' outside the battery pack and the real-time pressure P inside the battery pack is greater than or equal to the preset second explosion-proof opening pressure differential, the explosion-proof valve will also perform a pressure equalization operation. At this time, ambient air enters the battery pack through the explosion-proof valve, slowing the infiltration of external air. Simultaneously, the explosion-proof valve's built-in humidity control function reduces the ingress of large amounts of water vapor, preventing excessive humidity inside the battery pack.

[0070] In the first embodiment of the present application, the real-time pressure P inside the battery pack and the ambient pressure P outside the battery pack are ’ All are detected by pressure sensors.

[0071] In Example 1 of the present application, multiple sensors are strategically placed within the battery pack, including relative humidity sensors, wall temperature sensors, and pressure sensors. These sensors are positioned to cover key areas of the battery pack; for example, humidity sensors are placed close to the inner wall of the battery case, and near exposed copper bars and locations subject to significant temperature fluctuations. When installing the sensors, it is important to ensure that each sensor is fixed and stable to prevent displacement due to vibration during vehicle operation.

[0072] In the first embodiment of the present application, the humidity sensor uses dielectric polymer material as the main material, integrates temperature acquisition, and has a heating function; thus, the heating function of the humidity sensor can be used to heat the battery pack.

[0073] Furthermore, the relative humidity RHn inside the battery pack is measured by a humidity sensor, the wall temperature Tn inside the battery pack is measured by a wall temperature sensor, and the real-time pressure P inside the battery pack is measured by a pressure sensor.

[0074] In the first embodiment of the present application, the absolute humidity reference value AH0 is a value updated before the vehicle is powered off. Depending on the actual situation, the absolute humidity reference value may or may not be updated before the vehicle is powered off. When the vehicle's current absolute humidity reference value AH0 is needed, the current absolute humidity reference value AH0 is automatically retrieved from memory. The absolute humidity reference value AH0 is pre-stored in memory; when the battery pack is first shipped from the factory, the initial value of the absolute humidity reference value AH0 is a pre-calibrated value.

[0075] In step S103, the absolute humidity AHn1 is the mass of water vapor contained in a unit volume of air and can be calculated using the following formula: ; Where P1 is the saturation water vapor pressure; RHn is the relative humidity (dimensionless, range 0 to 1); is the molar mass of water vapor (18.015 g / mol); R is the ideal gas constant (8.314 J / (mol·K)); and T is the absolute temperature. In Example 1 of this application, the wall temperature Tn (°C) can be converted to the absolute temperature T using the following formula: T = Tn (°C) + 273.15.

[0076] Calculate the saturated water vapor pressure P1 by using the Antoine formula: , where A=8.07131, B=1730.63, C=233.426, and Tn is the wall temperature.

[0077] The dew point temperature T0 is the temperature at which water vapor in the air begins to condense into dew, which can be calculated using the following formula: ; Where A, B, and C are constants with values of 17.27, 237.7, and 610.78, respectively; P1 is the saturated water vapor pressure (Pa); and RHn is the relative humidity (dimensionless, ranging from 0 to 1).

[0078] The theoretical absolute humidity AHn2 is the absolute humidity assuming no gas leakage. In this case, the theoretical absolute humidity is the same as the actual absolute humidity, i.e., AHn2 = AHn1. In Example 1 of the present application, the theoretical absolute humidity AHn2 can be obtained by looking up the psychrometric table based on the relative humidity RHn and the wall temperature Tn.

[0079] Reference Figure 2 In the first embodiment of the present application, step S104 includes:

[0080] S1041: When the wall temperature Tn is less than or equal to the dew point temperature T0, if the absolute humidity AHn is less than the minimum value of the first humidity interval formed by the absolute humidity reference value AH0, the battery pack is heated. After the preset heating time, water ingress or condensation in the battery pack is detected based on the re-obtained relative humidity RHn'.

[0081] S1042: When it is determined that water ingress or condensation has occurred in the battery pack, a new absolute humidity AHn1' and a new theoretical absolute humidity AHn2' are re-determined based on the newly acquired relative humidity RHn' and wall temperature Tn'. The battery pack's airtightness is then identified based on the relative size of the new absolute humidity AHn1' and a second humidity range formed by the new theoretical absolute humidity AHn2'.

[0082] S1043 : When the wall temperature Tn is greater than the dew point temperature T0 , the airtightness of the battery pack is identified based on the relative size relationship between the absolute humidity AHn and the third humidity range formed by the absolute humidity reference value AH0 .

[0083] In S1041, if the wall temperature Tn ≤ the dew point temperature T0, water vapor in the air may condense into water droplets on the inner wall of the battery pack, causing condensation. Furthermore, if the absolute humidity AHn < the absolute humidity reference value AH0 − ΔAH1 (where ΔAH1 is a preset fluctuation threshold 1, and the absolute humidity reference value AH0 ± ΔAH1 constitutes the first humidity range), there is a risk of condensation or water ingress within the battery pack. Therefore, to prevent condensation or detect whether condensation has already occurred, the battery pack heating function is activated to heat the battery pack.

[0084] Heating the battery pack can reduce the relative humidity within the pack. Furthermore, the change in environmental conditions after heating can help the system determine whether condensation or water ingress has occurred. In the first embodiment of the present application, heating the battery pack is achieved by controlling a humidity sensor with a heating function installed within the battery pack. The humidity sensor continuously heats the battery pack for a preset duration (e.g., 5 minutes) to ensure that the wall temperature and relative humidity within the battery pack reach a new equilibrium state.

[0085] After the battery pack is heated, the relative humidity data RHn' in the battery pack is obtained again; by comparing the relative humidity changes before and after the battery pack is heated, it is determined whether condensation or water ingress has occurred.

[0086] If the relative humidity drops significantly after heating (i.e., the difference between the relative humidity RHn before heating and the recovered relative humidity RHn' is greater than a preset threshold), it indicates that water vapor in the air condensed into water droplets before heating, causing the relative humidity inside the battery pack to drop. This is a typical sign of condensation, and therefore, condensation is determined to have occurred within the battery pack. Conversely, if the relative humidity does not drop significantly, it indicates that liquid water may already be present inside the battery pack, rather than water vapor condensation. This is a typical sign of water ingress, and therefore, water ingress is determined to have occurred.

[0087] Then, based on the newly acquired relative humidity RHn' and wall temperature Tn', a new absolute humidity AHn1' and a new theoretical absolute humidity AHn2' are re-determined for the current environment. The new absolute humidity AHn1' and the new theoretical absolute humidity AHn2' are determined in the same manner as the theoretical humidity AHn1 and the theoretical absolute humidity AHn2 described above.

[0088] In S1042, the second humidity interval formed by the new theoretical absolute humidity AHn2' is, for example, [AHn'-ΔAH2, AHn'+ΔAH2], where ΔAH2 is the pre-set fluctuation threshold 2. If the new absolute humidity AHn1' is within the second humidity interval formed by the new theoretical absolute humidity AHn2', it indicates that the airtightness inside the battery pack is normal. If the new absolute humidity AHn1' is not within the second humidity interval formed by the new theoretical absolute humidity AHn2', it indicates that there may be a problem with the airtightness inside the battery pack, possibly due to gas leakage or water ingress. This detection method can effectively identify airtightness problems, ensure the sealing of the battery pack, and prevent battery performance degradation or safety hazards caused by gas leakage.

[0089] In S1043, when the wall temperature Tn is greater than the dew point temperature T0, it means that the water vapor in the battery pack is unlikely to condense into water droplets, and therefore the risk of condensation is low. In the first embodiment of the present application, the third humidity interval formed by the absolute humidity reference value AH0 is, for example, [AH0-ΔAH3, AH0+ΔAH3], where ΔAH3 is a pre-set fluctuation threshold of 3. If the absolute humidity AHn is within the third humidity interval, it indicates that the airtightness is normal; if the absolute humidity AHn exceeds the third humidity interval, it indicates that there may be an airtightness problem and gas leakage, and therefore it is determined that the battery pack airtightness has failed.

[0090] In step S105 , the insulation resistance of the vehicle is obtained using existing technology.

[0091] If only condensation is present, and the vehicle's insulation resistance remains below a predetermined normal value (e.g., 4000Ω / V) for a sustained period, a first prompt is issued to remind the user to replace the battery pack's moisture absorbent sheet. Condensation can increase humidity inside the battery pack, and long-term accumulation can affect battery performance and safety. Replacing the moisture absorbent sheet absorbs excess moisture, reducing the risk of condensation.

[0092] If only condensation is present and the vehicle's insulation resistance remains within a preset range (e.g., 1000Ω / V to 500Ω / V) for an extended period, a secondary notification alerts the user, warning them of insulation risks and requiring replacement of the battery pack's moisture absorbent sheet and airtightness inspection. The decrease in insulation resistance may be due to increased humidity caused by condensation, which can affect the battery pack's insulation over time. Therefore, the moisture absorbent sheet needs to be replaced and airtightness checked to ensure proper insulation performance. This prompt helps prevent potential safety hazards caused by insulation degradation, such as battery short circuits or fires.

[0093] If only the airtightness anomaly is present, a third reminder is issued, reminding the user to have the vehicle inspected and to avoid driving in flooded or rainy conditions. Airtightness anomalies can cause moisture to enter the battery pack, increasing the risk of water intrusion, especially when driving in flooded or rainy conditions. By prompting the user to promptly inspect the vehicle and avoid driving in inclement weather, the risk of water intrusion can be effectively reduced, ensuring safe vehicle operation.

[0094] If condensation is present and the battery pack experiences insulation failure, or if water intrusion occurs, the vehicle's use will be restricted, the battery's high voltage will be disconnected, and charging and discharging will be prohibited. The battery fault warning light on the instrument panel will illuminate. Insulation failure caused by condensation or water intrusion into the battery pack is a serious safety hazard that can cause a battery short circuit, fire, or even explosion. Restricting vehicle use, disconnecting the high-voltage circuit, and illuminating the warning light can effectively prevent accidents and protect the safety of both the user and the vehicle.

[0095] In the first embodiment of the present application, the method further includes:

[0096] S106: If the explosion-proof valve is currently performing an air pressure balancing operation, obtain the relative humidity, wall temperature, and real-time pressure inside the battery pack;

[0097] S107: If the relative humidity, wall temperature, and real-time pressure in the battery pack remain balanced within a predetermined period of time, the absolute humidity in the current environment is determined based on the relative humidity and wall temperature in the battery pack that are re-obtained after the balance, and the absolute humidity is updated to a new absolute humidity reference value.

[0098] If the explosion-proof valve is already balancing air pressure, there is a significant difference in air pressure inside and outside the battery pack, and the explosion-proof valve needs to be opened or closed to adjust the air pressure to achieve equilibrium. In this case, the environmental conditions inside the battery pack (such as real-time pressure, wall temperature, and relative humidity) may change significantly. If the old absolute humidity reference value is continued to be used, the monitoring results may deviate significantly from the actual environment, thereby affecting the system's judgment accuracy. By determining the absolute humidity based on the newly acquired relative humidity and wall temperature inside the battery pack and updating the absolute humidity reference value with the newly acquired absolute humidity, the humidity status of the battery pack can be more accurately monitored and judged.

[0099] In the first embodiment of the present application, the method further includes:

[0100] S108, before the vehicle is powered off, the relative humidity and wall temperature inside the battery pack are uploaded to the cloud;

[0101] S109, after being awakened by the cloud due to identification of condensation risk in the battery pack, determining whether the battery pack meets the heating conditions according to the battery pack heating instruction sent by the cloud;

[0102] S110: If the battery pack meets the heating conditions, the battery pack is heated until the wall temperature of the battery pack reaches the dew point temperature, and then the battery pack enters a dormant state; the dew point temperature is determined by the cloud based on the relative humidity and wall temperature of the battery pack uploaded before the vehicle is powered off;

[0103] S111, if the battery pack does not meet the heating conditions, it enters a dormant state after feeding back to the cloud that the battery pack does not meet the heating conditions, and updates the environmental data in the battery pack the next time it is awakened by the cloud because the real-time ambient temperature is lower than the dew point temperature.

[0104] Through steps S108-S111, the vehicle can prevent condensation in the battery pack by heating the battery pack in advance when there is a risk of condensation in the battery pack.

[0105] Through the above-mentioned power battery monitoring method in Example 1 of the present application, the actual operating status of the battery pack can be monitored in real time and accurately through key data such as relative humidity, wall temperature, real-time pressure, insulation resistance, absolute humidity and condensation status in the battery pack, thereby effectively preventing and responding to various hazards caused by abnormalities such as condensation, airtightness failure and water ingress in the battery pack.

[0106] Reference Figure 3 , Embodiment 2 of the present application further provides a power battery monitoring method, which is applied to the cloud, and the method includes:

[0107] S201, obtaining the relative humidity and wall temperature inside the battery pack uploaded by the vehicle before powering off;

[0108] S202, obtaining the ambient temperature forecast for the vehicle's location;

[0109] S203, determining the dew point temperature based on the relative humidity in the battery pack and the wall temperature;

[0110] At step S204 , if the relative humidity is greater than a preset humidity and the ambient forecast temperature is less than the maximum value of the temperature range formed by the dew point temperature, the vehicle is awakened, a condensation risk warning is sent to the vehicle, and a control instruction for battery pack heating is sent to the vehicle;

[0111] S205: If the battery pack does not meet the heating conditions as reported by the vehicle, the vehicle is awakened to update the environmental data in the battery pack when the real-time ambient temperature is lower than the dew point temperature.

[0112] In step S205, since the vehicle's battery pack does not meet the heating conditions, it cannot be guaranteed that the wall temperature inside the battery pack is greater than the dew point temperature. It is necessary to wake up the vehicle once when the real-time ambient temperature is lower than the dew point temperature before the vehicle is powered off, so that the vehicle updates the environmental data collected in the battery pack (the environmental data here includes: ambient temperature, relative humidity, insulation resistance and real-time pressure data).

[0113] In step S203, when the relative humidity is greater than the preset humidity and the ambient forecast temperature is less than the maximum value of the dew point temperature range, the cloud will immediately wake up the vehicle and push a condensation risk warning to it, while sending a control instruction to heat the battery pack. This proactive intervention measure can identify potential condensation problems in advance, rather than waiting until condensation has occurred, effectively avoiding damage to the battery pack caused by condensation.

[0114] Reference Figure 4 In the third embodiment of the present application, a power battery monitoring device is provided, including:

[0115] The first acquisition module 301 is used to obtain the current absolute humidity reference value of the vehicle;

[0116] A real-time parameter acquisition module 302 is used to obtain the relative humidity and wall temperature inside the battery pack if the explosion-proof valve is not currently performing an air pressure balancing action;

[0117] The parameter estimation module 303 is used to determine the absolute humidity, dew point temperature and theoretical absolute humidity in the current environment based on the relative humidity and wall temperature in the battery pack;

[0118] a detection module 304, configured to perform air tightness, condensation, and water ingress detection on the battery pack based on the relative relationship between the wall temperature and the dew point temperature, the relative relationship between the absolute humidity and the absolute humidity reference value, and the relative relationship between the absolute humidity and the theoretical absolute humidity;

[0119] The processing module 305 is configured to perform abnormality processing if at least one of the airtightness, condensation, and water ingress detection results of the battery pack is abnormal.

[0120] The power battery monitoring device in the third embodiment of the present application is a device corresponding to the power battery monitoring method in the first embodiment, and has the same technical effects as the first embodiment.

[0121] The fourth embodiment of the present application also provides a vehicle including the power battery monitoring device of the third embodiment.

[0122] It should be noted that the various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same and similar parts between the various embodiments can be referenced to each other.

[0123] Although the preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they become aware of the basic creative concepts. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the embodiments of the present invention.

[0124] It should also be noted that, in this document, the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are for the purpose of facilitating the description of the present invention and simplifying the description, rather than indicating or implying that the devices or components referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention. In addition, relational terms such as "first" and "second" are used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is any actual relationship or order between these entities or operations, nor should they be understood as indicating or implying relative importance. Moreover, the terms "comprises", "includes" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or terminal device comprising a series of elements does not include those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or terminal device. In the absence of further restrictions, an element defined by the sentence "comprising a ..." does not exclude the presence of other identical elements in the process, method, article or terminal device comprising the element.

[0125] The technical solutions provided by the present invention have been described in detail above. Specific examples are used herein to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is intended only to facilitate understanding of the present invention, and the contents of this specification should not be construed as limiting the present invention. Furthermore, those skilled in the art will appreciate that various modifications may be made to the specific implementation methods and scope of application according to the present invention. It is not necessary and impossible to exhaustively enumerate all implementation methods herein, and any obvious variations or modifications derived therefrom remain within the scope of protection of the present invention.

Claims

1. A power battery monitoring method, characterized in that: include: After the vehicle is powered on, determine whether the explosion-proof valve is currently performing the air pressure balancing action; If the explosion-proof valve is not currently performing an air pressure balancing action, obtain the absolute humidity reference value, the relative humidity inside the battery pack, and the wall temperature; Determine the absolute humidity, dew point temperature, and theoretical absolute humidity in the current environment based on the relative humidity and wall temperature inside the battery pack; Performing air tightness, condensation, and water ingress testing on the battery pack based on the relative relationship between the wall temperature and the dew point temperature, the relative relationship between the absolute humidity and the absolute humidity reference value, and the relative relationship between the absolute humidity and the theoretical absolute humidity specifically includes: When the wall temperature Tn is less than or equal to the dew point temperature T0, if the absolute humidity AHn1 is less than the minimum value of the first humidity interval formed by the absolute humidity reference value AH0, the battery pack is heated; after a preset heating time, water ingress or condensation in the battery pack is identified based on the re-acquired relative humidity RHn'; When water ingress or condensation is determined in the battery pack, the new absolute humidity AHn1' and the new theoretical absolute humidity AHn2' under the current environment are re-determined based on the re-acquired relative humidity RHn' and the wall temperature Tn'. The air tightness of the battery pack is identified based on the relative size of the new absolute humidity AHn1' and the second humidity range formed by the new theoretical absolute humidity AHn2'. If at least one of the battery pack's air tightness, condensation, and water ingress test results is abnormal, perform abnormal processing.

2. The power battery monitoring method according to claim 1, characterized in that: The method further comprises: Before the vehicle is powered off, the relative humidity and wall temperature inside the battery pack are uploaded to the cloud; After being awakened by the cloud due to the identification of condensation risk in the battery pack, the system determines whether the battery pack meets the heating conditions based on the battery pack heating instructions sent by the cloud; If the battery pack meets the heating conditions, the battery pack is heated until the wall temperature of the battery pack reaches the dew point temperature, after which the system enters a dormant state. The dew point temperature is determined by the cloud based on the relative humidity and wall temperature of the battery pack uploaded before the vehicle is powered off. If the battery pack does not meet the heating conditions, it will enter a dormant state after feeding back to the cloud that the battery pack does not meet the heating conditions, and will update the environmental data in the battery pack the next time it is awakened by the cloud because the real-time ambient temperature is lower than the dew point temperature.

3. The power battery monitoring method according to claim 1, characterized in that: The steps for identifying water ingress or condensation in the battery pack based on the re-acquired relative humidity RHn include: If the difference between the relative humidity RHn before the battery pack is heated and the re-obtained relative humidity RHn' is greater than a preset threshold, it is determined that condensation has occurred in the battery pack; If the difference between the relative humidity RHn before the battery pack is heated and the re-acquired relative humidity RHn' is less than or equal to a preset threshold, it is determined that water has entered the battery pack.

4. The power battery monitoring method according to claim 1, characterized in that: The steps of identifying the air tightness of the battery pack according to the relative size of the new absolute humidity AHn1' and the second humidity interval formed by the new theoretical absolute humidity AHn2' include: If the new absolute humidity AHn1' is within the second humidity interval formed by the new theoretical absolute humidity AHn2', it is determined that the battery pack is airtight. If the new absolute humidity AHn1 ′ is not within the second humidity interval formed by the new theoretical absolute humidity AHn2 ′, it is determined that the airtightness of the battery pack has failed.

5. The power battery monitoring method according to claim 1, characterized in that: The step of performing air tightness, condensation, and water ingress testing on the battery pack according to the relative relationship between the wall temperature and the dew point temperature, the relative relationship between the absolute humidity and the absolute humidity reference value, and the relative relationship between the absolute humidity and the theoretical absolute humidity further includes: When the wall surface temperature Tn is greater than the dew point temperature T0, the airtightness of the battery pack is identified based on the relative magnitude relationship between the absolute humidity AHn and a third humidity range formed by the absolute humidity reference value AH0.

6. The power battery monitoring method according to claim 5, characterized in that: The step of identifying the airtightness of the battery pack according to the relative magnitude relationship between the absolute humidity AHn and a third humidity interval formed by the absolute humidity reference value AH0 includes: If the absolute humidity AHn is within a third humidity interval formed by the absolute humidity reference value AH0, it is determined that the airtightness of the battery pack is normal; If the absolute humidity AHn is not within the third humidity interval formed by the absolute humidity reference value AH0 , it is determined that the airtightness of the battery pack has failed.

7. The power battery monitoring method according to claim 1 or 2, characterized in that: The battery pack is heated by controlling a humidity sensor with a heating function provided in the battery pack.

8. The power battery monitoring method according to claim 1, characterized in that: The method further comprises: If the explosion-proof valve is currently performing an air pressure balancing action, obtain the relative humidity, wall temperature, and real-time pressure inside the battery pack; If the relative humidity, wall temperature and real-time pressure inside the battery pack remain balanced within a predetermined period of time, the absolute humidity in the current environment is determined based on the relative humidity and wall temperature inside the battery pack that are re-obtained after balance, and the absolute humidity is updated to a new absolute humidity reference value.

9. The power battery monitoring method according to claim 1, characterized in that: If at least one of the battery pack air tightness, condensation, and water ingress test results is abnormal, the abnormality handling steps include: If only condensation anomaly exists, and the vehicle's insulation resistance value is not less than the predetermined normal value for a long time, a first prompt is output to remind the user to replace the battery pack's moisture absorbent sheet; If only condensation anomalies exist and the vehicle's insulation resistance remains within the preset insulation resistance range for a long period of time, a second prompt will be output to remind the user that there is an insulation risk in the vehicle and that the battery pack's moisture absorbent sheet needs to be replaced and the airtightness repaired. If only the airtightness is abnormal, a third prompt is output to remind the user to have the vehicle inspected and to avoid driving on flooded roads and in rainy weather. If there is abnormal condensation and the battery pack has an insulation failure, or water has entered the battery pack, the vehicle's use will be restricted, the battery high voltage will be cut off, and charging and discharging will be prohibited. The battery fault warning light on the instrument panel will be illuminated.

10. A power battery monitoring method, characterized in that: Applied to the cloud according to claim 2, the method comprises: Obtain the relative humidity and wall temperature inside the battery pack uploaded by the vehicle before power is turned off; Obtain the ambient temperature forecast for the vehicle's location; Determine the dew point temperature based on the relative humidity and wall temperature inside the battery pack; If the relative humidity is greater than a preset humidity and the ambient forecast temperature is less than the maximum value of the temperature range formed by the dew point temperature, the vehicle is awakened, a condensation risk warning is sent to the vehicle, and a control instruction for heating the battery pack is sent to the vehicle; If the battery pack does not meet the heating conditions as reported by the vehicle, the vehicle is awakened to update the environmental data in the battery pack when the real-time ambient temperature is lower than the dew point temperature.

11. A power battery monitoring device, characterized in that: include: A first acquisition module is used to obtain the current absolute humidity reference value of the vehicle; A real-time parameter acquisition module is used to obtain the relative humidity and wall temperature inside the battery pack if the explosion-proof valve is not currently performing pressure balancing. The parameter estimation module is used to determine the absolute humidity, dew point temperature and theoretical absolute humidity in the current environment based on the relative humidity and wall temperature in the battery pack; The detection module is configured to perform air tightness, condensation, and water ingress detection on the battery pack based on the relative relationship between the wall temperature and the dew point temperature, the relative relationship between the absolute humidity and the absolute humidity reference value, and the relative relationship between the absolute humidity and the theoretical absolute humidity, specifically comprising: When the wall temperature Tn is less than or equal to the dew point temperature T0, if the absolute humidity AHn1 is less than the minimum value of the first humidity interval formed by the absolute humidity reference value AH0, the battery pack is heated; after a preset heating time, water ingress or condensation in the battery pack is identified based on the re-acquired relative humidity RHn'; When water ingress or condensation is determined in the battery pack, the new absolute humidity AHn1' and the new theoretical absolute humidity AHn2' under the current environment are re-determined based on the re-acquired relative humidity RHn' and the wall temperature Tn'. The air tightness of the battery pack is identified based on the relative size of the new absolute humidity AHn1' and the second humidity range formed by the new theoretical absolute humidity AHn2'. The processing module is used to perform abnormal processing if there is at least one abnormality in the air tightness, condensation and water ingress detection results of the battery pack.

12. A vehicle, characterized in that: Including the power battery monitoring device according to claim 11.

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