Power battery monitoring method and device and vehicle

Abstract

The invention provides a power battery monitoring method, a power battery monitoring device and a vehicle. The power battery monitoring method and the power battery monitoring device are used for detecting air tightness, condensation and water inflow of a power battery. The power battery monitoring method comprises the following steps: after a whole vehicle is powered on, judging whether an explosion-proof valve carries out an air pressure balancing action or not at present; if the explosion-proof valve does not perform the air pressure balancing action at present, acquiring an absolute humidity reference value, and relative humidity and wall surface temperature in the battery pack; according to the relative humidity and the wall surface temperature in the battery pack, determining absolute humidity, dew point temperature and theoretical absolute humidity in the current environment; according to the relative size relation between the wall surface temperature and the dew point temperature, the relative size relation between the absolute humidity and the absolute humidity reference value and the relative size relation between the absolute humidity and the theoretical absolute humidity, air tightness, condensation and water inflow of the battery pack are detected; and if at least one of the air tightness, condensation and water inflow detection results of the battery pack is abnormal, carrying out abnormity processing.

Description

Technical Field

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

[0002] With the rapid development of the new energy vehicle industry in China, it is playing an increasingly important role in the global market at the same time. Consumers have higher expectations for the safety performance of new energy vehicles. As the core component of new energy vehicles, the safety of power batteries and the safety monitoring throughout the life cycle have gradually become the primary considerations for consumers when purchasing vehicles. The safe use of power batteries throughout their life cycle is directly affected by the humidity and airtightness in the operating environment. It is particularly important to detect the humidity and airtightness of power batteries.

[0003] During the operation of a power battery, it is usually necessary to maintain a high degree of airtightness to ensure its performance and safety. Once the airtightness fails, moisture, dust or other impurities in the external environment will enter the battery interior, causing serious harm to the performance and safety of the battery. The following are the main hazards of airtightness failure to power batteries: (1) Moisture intrusion leads to a decline in battery performance, manifested as a change in the performance of the electrolyte, a decrease in battery capacity, and an increase in internal resistance; (2) The entry of external impurities causes safety hazards, mainly manifested as short-circuit risk, corrosion risk, and thermal runaway risk; (3) Airtightness failure leads to unstable pressure, mainly manifested as gas leakage and battery swelling; (4) It affects the cycle life of the battery, mainly manifested as accelerated aging and monomer consistency problems. Summary of the Invention

[0004] The present application provides a method and device for monitoring a power battery and a vehicle, which are used to realize the detection of the airtightness, condensation and water ingress of the power battery.

[0005] The technical solution of the present application is as follows: The present application provides a method for monitoring a power battery, including: After the vehicle is powered on, determine whether the explosion-proof valve is currently performing a balanced air pressure operation; If the explosion-proof valve is not currently performing a balanced air pressure operation, obtain the absolute humidity reference value, the relative humidity inside the battery pack, and the wall temperature; According to the relative humidity inside the battery pack and the wall temperature, determine the absolute humidity, dew point temperature, and theoretical absolute humidity under the current environment; According to the relative magnitude relationship between the wall temperature and the dew point temperature, the relative magnitude relationship between the absolute humidity and the absolute humidity reference value, and the relative magnitude relationship between the absolute humidity and the theoretical absolute humidity, perform the detection of the airtightness, condensation and water ingress of the battery pack; If there is at least one abnormality in the airtightness, condensation, and water ingress detection results of the battery pack, perform abnormality handling.

[0006] Preferably, the method further includes: Before the vehicle is powered off, upload the relative humidity and wall temperature inside the battery pack to the cloud; After being woken up by the cloud due to the recognition of condensation risk in the battery pack, determine whether the battery pack meets the heating conditions according to the battery pack heating instruction sent by the cloud; If the battery pack meets the heating conditions, heat the battery pack until the wall temperature of the battery pack reaches the dew point temperature and then enter the sleep state; the dew point temperature is determined by the cloud according to the relative humidity and wall temperature inside the battery pack uploaded before the vehicle is powered off; If the battery pack does not meet the heating conditions, enter the sleep state after feedback to the cloud that the battery pack does not meet the heating conditions, and update the environmental data inside the battery pack when it is woken up by the cloud again due to the real-time ambient temperature being less than the dew point temperature next time.

[0007] Preferably, according to the relative magnitude relationship between the wall temperature and the dew point temperature, the relative magnitude relationship between the absolute humidity and the absolute humidity reference value, and the relative magnitude relationship between the absolute humidity and the theoretical absolute humidity, the steps of performing airtightness, condensation, and water ingress detection on the battery pack include: 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 range formed by the absolute humidity reference value AH0, heat the battery pack; after heating for a preset duration, identify water ingress or condensation in the battery pack according to the newly obtained relative humidity RHn'; When it is determined that water ingress or condensation has occurred in the battery pack, re-determine the new absolute humidity AHn1' and the new theoretical absolute humidity AHn2' in the current environment according to the newly obtained relative humidity RHn' and the wall temperature Tn', and perform airtightness identification on the battery pack according to the relative magnitude between the new absolute humidity AHn1' and the second humidity range formed by the new theoretical absolute humidity AHn2'.

[0008] Preferably, the steps of identifying water ingress or condensation in the battery pack according to the newly obtained relative humidity RHn include: If the difference between the relative humidity RHn before battery pack heating and the newly obtained relative humidity RHn' is greater than the preset threshold, determine that condensation has occurred in the battery pack; If the difference between the relative humidity RHn before battery pack heating and the newly obtained relative humidity RHn' is less than or equal to the preset threshold, determine that water ingress has occurred in the battery pack.

[0009] Preferably, according to the relative magnitudes of the new absolute humidity AHn1' and the second humidity range formed by the new theoretical absolute humidity AHn2', the steps for identifying the airtightness of the battery pack include: If the new absolute humidity AHn1' is within the second humidity range formed by the new theoretical absolute humidity AHn2', it is determined that the airtightness of the battery pack is normal; If the new absolute humidity AHn1' is not within the second humidity range formed by the new theoretical absolute humidity AHn2', it is determined that the airtightness of the battery pack fails.

[0010] Preferably, according to the relative magnitude relationship between the wall temperature and the dew point temperature, the relative magnitude relationship between the absolute humidity and the absolute humidity reference value, and the relative magnitude relationship between the absolute humidity and the theoretical absolute humidity, the steps for detecting the airtightness, condensation, and water ingress of the battery pack further include: When the wall temperature Tn is greater than the dew point temperature T0, according to the relative magnitude relationship between the absolute humidity AHn and the third humidity range formed by the absolute humidity reference value AH0, the airtightness of the battery pack is identified.

[0011] Preferably, according to the relative magnitude relationship between the absolute humidity AHn and the third humidity range formed by the absolute humidity reference value AH0, the steps for identifying the airtightness of the battery pack include: If the absolute humidity AHn is within the third humidity range 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 range formed by the absolute humidity reference value AH0, it is determined that the airtightness of the battery pack fails.

[0012] Preferably, the battery pack is heated by controlling a humidity sensor with a heating function provided inside the battery pack.

[0013] Preferably, the method further includes: If the explosion-proof valve is currently performing an equalizing air pressure operation, 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 time period, then according to the relative humidity and wall temperature inside the battery pack re-obtained after balancing, determine the absolute humidity in the current environment, and update the absolute humidity as the new absolute humidity reference value.

[0014] Preferably, if there is at least one abnormality in the detection results of the airtightness, condensation, and water ingress of the battery pack, the steps for performing abnormality handling include: If there is only condensation abnormality and the insulation resistance value of the vehicle does not remain less than the predetermined normal value for a long time, a first prompt is output to remind the user to replace the moisture absorbent sheet of the battery pack; If there is only condensation abnormality and the insulation resistance value of the vehicle remains within the preset insulation resistance range for a long time, a second prompt is output to remind the user that the vehicle has an insulation risk and the moisture absorbent sheet of the battery pack needs to be replaced and the airtightness needs to be inspected; If there is only airtightness abnormality, a third prompt is output to remind the user to perform vehicle inspection and avoid driving through wading sections and in rainy weather; If there is condensation abnormality and the battery pack has an insulation fault, or the battery pack is flooded, the vehicle use is restricted, the high voltage of the battery is cut off to prohibit charging and discharging, and the battery fault warning light on the instrument panel is lit.

[0015] This application also provides a power battery monitoring method, which is applied to the cloud. The method includes: Obtaining the relative humidity and wall temperature inside the battery pack uploaded by the vehicle before powering off; Obtaining the environmental forecast temperature at the location where the vehicle is located; Determining the dew point temperature according to the relative humidity and wall temperature inside the battery pack; If the relative humidity is greater than the preset humidity and the environmental forecast temperature is less than the maximum value of the temperature range composed of the dew point temperature, the vehicle is awakened, a condensation risk warning is pushed to the vehicle, and a control command for heating the battery pack is sent to the vehicle; If it is received that the battery pack does not meet the heating condition feedback from the vehicle, when the real-time environmental temperature is less than the dew point temperature, the vehicle is awakened to update the environmental data inside the battery pack.

[0016] This application also provides a power battery monitoring device, including: A first acquisition module, configured to acquire the current absolute humidity reference value of the vehicle; A real-time parameter acquisition module, configured to acquire the relative humidity and wall temperature inside the battery pack if the explosion-proof valve is not currently performing a balanced air pressure action; A parameter calculation module, configured to determine the absolute humidity, dew point temperature, and theoretical absolute humidity under the current environment according to the relative humidity and wall temperature inside the battery pack; A detection module, configured to perform airtightness, condensation, and water ingress detection of the battery pack according to the relative magnitude relationship between the wall temperature and the dew point temperature, the relative magnitude relationship between the absolute humidity and the absolute humidity reference value, and the relative magnitude relationship between the absolute humidity and the theoretical absolute humidity; A processing module, configured to perform abnormal processing if at least one of the airtightness, condensation, and water ingress detection results of the battery pack is abnormal.

[0017] The present application also provides a vehicle, including the above-mentioned power battery monitoring device.

[0018] The beneficial effects of the present invention are as follows: Based on the relative humidity and wall humidity inside the battery pack, accurately determine the absolute humidity, dew point temperature, and theoretical absolute humidity under the current environment, and according to these parameters, monitor the actual operating status of the battery pack in real time and accurately, so as to effectively prevent and respond to various hazards brought by abnormalities such as condensation, airtightness failure, and water ingress in the battery pack. Description of the Drawings

[0019] Figure 1 It is a schematic flowchart of the power battery monitoring method in Embodiment 1 of the present application; Figure 2 It is a schematic flowchart of step S104 in Embodiment 1 of the present application; Figure 3 It is a schematic flowchart of the power battery monitoring method applied to the cloud in Embodiment 2 of the present application; Figure 4 It is a schematic flowchart of the power battery monitoring device in Embodiment 3 of the present application. Detailed Embodiments

[0020] The method of the present invention will be further described below in conjunction with embodiments and accompanying drawings. This embodiment is implemented on the premise of the technical solution of the present invention, and detailed implementation methods and specific operation processes are given, but the protection scope of the present invention is not limited to the following embodiments.

[0021] Refer to Figure 1 , Embodiment 1 of the present application provides a power battery monitoring method, including: S101, after the vehicle is powered on, determine whether the explosion-proof valve is currently performing a balanced air pressure action; S102, if the explosion-proof valve is not currently performing a balanced air pressure action, obtain the absolute humidity reference value, the relative humidity inside the battery pack, and the wall temperature; S103, based on the relative humidity and wall temperature inside the battery pack, determine the absolute humidity, dew point temperature, and theoretical absolute humidity in each current environment; S104, based on the relative magnitude relationship between the wall temperature and the dew point temperature, the relative magnitude relationship between the absolute humidity and the absolute humidity reference value, and the relative magnitude relationship between the absolute humidity and the theoretical absolute humidity, perform airtightness, condensation, and water ingress detection on the battery pack; S105, if there is at least one abnormality in the airtightness, condensation, and water ingress detection results of the battery pack, perform abnormality handling.

[0022] The application object of the power battery monitoring method in the first embodiment of the present application is a vehicle-mounted controller, for example, a vehicle controller, a battery management system, etc. The application scenario of the method is after the vehicle is powered on.

[0023] In step S101, it is determined whether the explosion-proof valve is currently performing a gas pressure balancing action based on the real-time pressure inside the battery pack and the real-time pressure outside the battery pack.

[0024] The specific structural form of the explosion-proof valve does not belong to the improvement point of the present application. The existing explosion-proof valve structure in the art can be adopted and is not limited in the embodiments of the present application.

[0025] 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 difference, the explosion-proof valve will release pressure to the outside until the pressure difference is less than the first explosion-proof opening pressure difference, and the explosion-proof valve will close. In addition, 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 difference, the explosion-proof valve will also perform an air pressure balance operation. At this time, the gas in the environment enters the battery pack through the explosion-proof valve, slowing down the infiltration speed of external gas; at the same time, the humidity control function of the explosion-proof valve will reduce the large amount of water vapor entering, preventing the humidity in the battery pack from being too high.

[0026] 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 ’ All are detected by pressure sensors.

[0027] In the first embodiment of the present application, multiple sensors are reasonably arranged in the battery pack, including relative humidity sensors, wall temperature sensors and pressure sensors. The arrangement positions of these sensors should cover the key areas of the battery pack; for example, a humidity sensor is set close to the inner wall of the battery box, and a humidity sensor is set close to the exposed metal copper bus and the location where the temperature changes drastically. When installing the sensor, it is necessary to ensure that the installation position of each sensor is fixed and stable to avoid displacement of the sensor due to vibration during vehicle driving.

[0028] In the first embodiment of the present application, the humidity sensor selects 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.

[0029] 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.

[0030] In the first embodiment of the present application, the absolute humidity reference value AH0 is the value updated before the vehicle is powered off. Among them, according to the actual situation, there are cases where the absolute humidity reference value is updated or not updated before the vehicle is powered off. When it is necessary to obtain the current absolute humidity reference value AH0 of the vehicle, the current absolute humidity reference value AH0 is automatically obtained from the memory. Among them, the absolute humidity reference value AH0 is pre-stored in the memory; when the battery pack just leaves the factory, the initial value of the absolute humidity reference value AH0 is the pre-calibrated value.

[0031] In step S103, the absolute humidity AHn1 is the mass of water vapor contained in a unit volume of air; it can be calculated by the following formula: ; where P1 is the saturated 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)); T is the absolute temperature. In the first embodiment of the present application, the following formula can be used: T = Tn(°C) + 273.15, to convert the wall temperature Tn (°C) to the absolute temperature T.

[0032] The saturated water vapor pressure P1 is calculated by using the Antoine formula: , where A = 8.07131, B = 1730.63, C = 233.426, and Tn is the wall temperature.

[0033] The dew point temperature T0 is the temperature at which the water vapor in the air begins to condense into dew, and it can be calculated by 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); RHn is the relative humidity (dimensionless, range 0 to 1).

[0034] The theoretical absolute humidity AHn2 is the absolute humidity assuming no gas leakage. In the case of no gas leakage, the theoretical absolute humidity is the same as the actual absolute humidity, that is: AHn2 = AHn1. In the first embodiment of the present application, the theoretical absolute humidity AHn2 can be obtained by looking up the enthalpy-humidity table according to the relative humidity RHn and the wall temperature Tn.

[0035] Refer to Figure 2 , in the first embodiment of the present application, step S104 includes: 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 range composed of the absolute humidity reference value AH0, the battery pack is heated; after heating for a preset duration, the water ingress or condensation of the battery pack is identified according to the newly obtained relative humidity RHn'; S1042. When it is determined that the battery pack has water ingress or condensation, based on the newly obtained relative humidity RHn' and wall temperature Tn', the new absolute humidity AHn1’ and the new theoretical absolute humidity AHn2’ under the current environment are re-determined, and the airtightness of the battery pack is identified according to the relative magnitudes of the new absolute humidity AHn1’ and the second humidity range formed by the new theoretical absolute humidity AHn2’. S1043. When the wall temperature Tn is greater than the dew point temperature T0, the airtightness of the battery pack is identified according to the relative magnitude relationship between the absolute humidity AHn and the third humidity range formed by the absolute humidity reference value AH0.

[0036] Among them, 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, resulting in a condensation phenomenon. 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 forms the first humidity range), it indicates that there is a risk of condensation or water ingress in the battery pack. Therefore, in order to prevent condensation or detect whether condensation has occurred, the battery pack heating function is activated to heat the battery pack.

[0037] Heating the battery pack can reduce the relative humidity inside the battery pack. At the same time, the change in the environmental conditions after heating can help the system determine whether condensation or water ingress has occurred. In the first embodiment of the present application, when heating the battery pack, the battery pack heating is realized by controlling the humidity sensor with a heating function provided inside the battery pack. The battery pack is continuously heated by this humidity sensor for a preset duration (such as 5 minutes) to ensure that the wall temperature and relative humidity inside the battery pack reach a new equilibrium state.

[0038] After the battery pack heating is completed, the relative humidity data RHn' inside the battery pack is newly obtained; by comparing the relative humidity change before and after the battery pack heating, it is determined whether condensation or water ingress has occurred.

[0039] If the relative humidity after heating drops significantly (that is, the difference between the relative humidity RHn before the battery pack heating and the newly obtained relative humidity RHn' is greater than the preset threshold), it indicates that water vapor in the air has condensed into water droplets before heating, resulting in a decrease in the relative humidity inside the battery pack. This is a typical feature of condensation, so it is determined that condensation has occurred inside the battery pack. On the contrary, if the relative humidity does not drop significantly, it indicates that there may already be liquid water inside the battery pack instead of water vapor condensation. This is a typical feature of water ingress, so it is determined that the battery pack has water ingress.

[0040] Furthermore, based on the newly obtained relative humidity RHn' and wall temperature Tn', the new absolute humidity AHn1’ and the new theoretical absolute humidity AHn2’ under the current environment are re-determined. Among them, the determination methods of the new absolute humidity AHn1’ and the new theoretical absolute humidity AHn2’ are the same as those of the aforementioned theoretical humidity AHn1 and theoretical absolute humidity AHn2.

[0041] In S1042, the second humidity range composed of the new theoretical absolute humidity AHn2’ is, for example, [AHn'−ΔAH2, AHn'+ΔAH2], where ΔAH2 is a preset fluctuation threshold 2. If the new absolute humidity AHn1’ is within the second humidity range composed of 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 range composed of the new theoretical absolute humidity AHn2’, it indicates that there may be a problem with the airtightness inside the battery pack, and there may be gas leakage or water ingress. This detection method can effectively identify airtightness problems, ensure the sealing of the battery pack, and prevent the degradation of battery performance or safety hazards caused by gas leakage.

[0042] In S1043, when the wall temperature Tn is greater than the dew point temperature T0, it means that the water vapor inside the battery pack is less likely to condense into water droplets, so the risk of condensation is relatively low. In the first embodiment of the present application, the third humidity range composed of the absolute humidity reference value AH0 is, for example, [AH0−ΔAH3, AH0+ΔAH3], where ΔAH3 is a preset fluctuation threshold 3. If the absolute humidity AHn is within the third humidity range, it indicates that the airtightness is normal; if the absolute humidity AHn exceeds the third humidity range, it indicates that there may be a problem with the airtightness and there may be gas leakage, so it is determined that the airtightness of the battery pack fails.

[0043] In step S105, the insulation resistance value of the vehicle is obtained by using the existing technology.

[0044] Among them, if there is only condensation abnormality and the insulation resistance value of the vehicle is not less than the predetermined normal value (the predetermined normal value is, for example, 4000Ω / V) for a long time, a first prompt for reminding the user to replace the moisture absorbent sheet of the battery pack is output. Since condensation may cause an increase in the internal humidity of the battery pack, long-term accumulation may affect battery performance and safety; replacing the moisture absorbent sheet can absorb excess moisture and reduce the risk of condensation.

[0045] If there is only condensation abnormality, when the insulation resistance value of the vehicle remains within the preset insulation resistance range for a long time (for example, between 1000Ω / V - 500Ω / V), a second prompt is output to remind the user that there is an insulation risk in the vehicle and the moisture absorbent sheet of the battery pack needs to be replaced and the airtightness needs to be checked. Among them, the decrease in insulation resistance value may be due to the increased humidity caused by condensation, which may affect the insulation performance of the battery pack in the long term; therefore, it is necessary to replace the moisture absorbent sheet and check the airtightness to ensure the insulation performance of the battery pack. By reminding the user to take timely measures, potential safety hazards caused by the decline of insulation performance, such as battery short circuit or fire, can be avoided.

[0046] If there is only airtightness abnormality, a third prompt is output to remind the user to perform vehicle maintenance and avoid driving through wading sections and in rainy weather. Abnormal airtightness may cause external moisture to enter the battery pack, especially when wading or in rainy weather, increasing the risk of water ingress; by reminding the user to perform timely maintenance and avoid driving in bad weather, the risk of water ingress into the battery pack can be effectively reduced, ensuring the safe operation of the vehicle.

[0047] If there is condensation abnormality and the battery pack has an insulation fault, or the battery pack is flooded with water, the vehicle use is restricted, the high voltage of the battery is cut off to prohibit charging and discharging, and the battery fault warning light on the instrument panel is lit. The insulation fault caused by condensation or the battery pack being flooded with water is a serious safety hazard, which may lead to battery short circuit, fire or even explosion; by restricting vehicle use, cutting off the high voltage circuit and lighting the warning light, the occurrence of accidents can be effectively prevented, protecting the safety of users and vehicles.

[0048] In the first embodiment of the present application, the method further includes: S106, if the explosion-proof valve is currently performing the air pressure balancing action, obtain the relative humidity, wall temperature and real-time pressure inside the battery pack; S107, if the relative humidity, wall temperature and real-time pressure inside the battery pack remain balanced within a preset time period, determine the absolute humidity under the current environment according to the relative humidity and wall temperature inside the battery pack obtained again after balancing, and update the absolute humidity to a new absolute humidity reference value.

[0049] If the explosion-proof valve is already performing the air pressure balancing action, it indicates that there is a significant difference in air pressure between the inside and outside of the battery pack, and it is necessary to adjust the air pressure by opening or closing the explosion-proof valve to make it reach the balanced state. 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 continues to be used, the monitoring results may deviate greatly from the actual environment, thus affecting the judgment accuracy of the system; by determining the absolute humidity according to the relative humidity and wall temperature inside the battery pack obtained again, and updating the absolute humidity reference value with the newly obtained absolute humidity, the humidity state of the battery pack can be monitored and judged more accurately.

[0050] In the first embodiment of the present application, the method further includes: S108. Before the vehicle is powered off, upload the relative humidity and wall temperature inside the battery pack to the cloud; S109. After being woken up by the cloud due to identifying a condensation risk in the battery pack, determine whether the battery pack meets the heating condition according to the battery pack heating instruction sent by the cloud; S110. If the battery pack meets the heating condition, heat the battery pack until the wall temperature of the battery pack reaches the dew point temperature and then enter the sleep state; the dew point temperature is determined by the cloud according to the relative humidity and wall temperature inside the battery pack uploaded before the vehicle is powered off; S111. If the battery pack does not meet the heating condition, enter the sleep state after feeding back to the cloud that the battery pack does not meet the heating condition, and update the environmental data inside the battery pack when it is woken up by the cloud again due to the real-time environmental temperature being less than the dew point temperature.

[0051] Through steps S108 - S111, the vehicle can heat the battery pack in advance when there is a condensation risk in the battery pack, avoiding condensation in the battery pack.

[0052] Through the above power battery monitoring method in the first embodiment of the present application, the actual operating state of the battery pack can be monitored in real time and accurately through key data such as the relative humidity, wall temperature, real-time pressure, insulation resistance value, absolute humidity, and condensation state inside the battery pack, thereby effectively preventing and coping with various hazards brought by abnormalities such as condensation, airtightness failure, and water ingress in the battery pack.

[0053] Refer to Figure 3 , the second embodiment of the present application also provides a power battery monitoring method, which is applied to the cloud, and the method includes: S201. Obtain the relative humidity and wall temperature inside the battery pack uploaded by the vehicle before it is powered off; S202. Obtain the environmental forecast temperature at the location where the vehicle is located; S203. Determine the dew point temperature according to the relative humidity and wall temperature inside the battery pack; S204. If the relative humidity is greater than the preset humidity and the environmental forecast temperature is less than the maximum value of the temperature range composed of the dew point temperature, wake up the vehicle, push a condensation risk warning to the vehicle, and send a control instruction to heat the battery pack to the vehicle; S205. If it receives feedback from the vehicle that the battery pack does not meet the heating condition, wake up the vehicle to update the environmental data inside the battery pack when the real-time environmental temperature is less than the dew point temperature.

[0054] In step S205, since the battery pack of the vehicle does not meet the heating condition and cannot ensure 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 less than the dew point temperature before the vehicle is powered off, so that the vehicle can update the ambient data collected inside the battery pack (the ambient data here includes: ambient temperature, relative humidity, insulation resistance value, and real-time pressure data).

[0055] 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, and at the same time send 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.

[0056] Refer to Figure 4 , in Embodiment 3 of the present application, a power battery monitoring device is provided, including: A first acquisition module 301, configured to acquire the current absolute humidity reference value of the vehicle; A real-time parameter acquisition module 302, configured to acquire the relative humidity and wall temperature inside the battery pack if the explosion-proof valve is not currently performing a balanced air pressure action; A parameter calculation module 303, configured to determine the absolute humidity, dew point temperature, and theoretical absolute humidity in the current environment according to the relative humidity and wall temperature inside the battery pack; A detection module 304, configured to perform airtightness, condensation, and water ingress detection of the battery pack according to the relative magnitude relationship between the wall temperature and the dew point temperature, the relative magnitude relationship between the absolute humidity and the absolute humidity reference value, and the relative magnitude relationship between the absolute humidity and the theoretical absolute humidity; A processing module 305, configured to perform anomaly processing if at least one of the airtightness, condensation, and water ingress detection results of the battery pack is abnormal.

[0057] The power battery monitoring device in Embodiment 3 of the present application is a device corresponding to the power battery monitoring method in Embodiment 1, and it has the same technical effect as that of Embodiment 1.

[0058] In Embodiment 4 of the present application, a vehicle including the power battery monitoring device in Embodiment 3 is further provided.

[0059] It should be noted that the various embodiments in this specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments. The same or similar parts among the various embodiments can be referred to each other.

[0060] Although the preferred embodiments of the embodiments of the present invention have been described, those skilled in the art can make additional changes and modifications to these embodiments once they know the basic creative concept. Therefore, the appended claims are intended to be construed to include the preferred embodiments as well as all changes and modifications falling within the scope of the embodiments of the present invention.

[0061] It should also be noted that in this document, the orientation or positional relationships indicated by terms such as "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. are based on the orientation or positional relationships shown in the drawings. This is for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or component referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation on 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 any actual relationship or order between these entities or operations, nor can they be construed as indicating or implying relative importance. Moreover, the term "comprising", "including" or any other variant thereof is 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 expressly listed, or elements inherent to such process, method, article or terminal device. Without further limitation, an element defined by the statement "comprising an..." does not exclude the existence of additional identical elements in the process, method, article or terminal device comprising the element.

[0062] The technical solutions provided by the present invention have been introduced in detail above. Specific examples are used in this article to elaborate on the principles and implementation manners of the present invention. The description of the above embodiments is only for helping to understand the present invention, and the content of this specification should not be construed as a limitation on the present invention. At the same time, for those of ordinary skill in the art, according to the present invention, there will be various forms of changes in the specific implementation manners and application scopes. It is not necessary and impossible to list all the implementation manners here, and the obvious changes or variations derived therefrom are still within the protection scope of the present invention.

Claims

1. A power battery monitoring method, characterized in that, Including: After the vehicle is powered on, determine whether the explosion-proof valve is currently performing the balanced air pressure action; If the explosion-proof valve is not currently performing the balanced air pressure action, obtain the absolute humidity reference value, the relative humidity inside the battery pack, and the wall temperature; Based on 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 magnitude relationship between the wall temperature and the dew point temperature, the relative magnitude relationship between the absolute humidity and the absolute humidity reference value, and the relative magnitude relationship between the absolute humidity and the theoretical absolute humidity, perform airtightness, condensation, and water ingress detection on the battery pack; If at least one of the airtightness, condensation, and water ingress detection results of the battery pack is abnormal, perform abnormal handling.

2. The power battery monitoring method according to claim 1, wherein, The method further includes: Before the vehicle is powered off, upload the relative humidity inside the battery pack and the wall temperature to the cloud; After being awakened by the cloud due to the recognition of a condensation risk in the battery pack, determine whether the battery pack meets the heating condition according to the battery pack heating instruction sent by the cloud; If the battery pack meets the heating condition, heat the battery pack until the wall temperature of the battery pack reaches the dew point temperature and then enter the sleep state; the dew point temperature is determined by the cloud based on the relative humidity inside the battery pack and the wall temperature uploaded before the vehicle is powered off; If the battery pack does not meet the heating condition, enter the sleep state after feedback to the cloud that the battery pack does not meet the heating condition, and update the environmental data inside the battery pack when being awakened by the cloud again due to the real-time environmental temperature being less than the dew point temperature next time.

3. The power battery monitoring method according to claim 1, wherein The step of performing airtightness, condensation, and water ingress detection on the battery pack based on the relative magnitude relationship between the wall temperature and the dew point temperature, the relative magnitude relationship between the absolute humidity and the absolute humidity reference value, and the relative magnitude relationship between the absolute humidity and the theoretical absolute humidity 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 range composed of the absolute humidity reference value AH0, heat the battery pack; after heating for a preset duration, perform water ingress or condensation recognition on the battery pack according to the newly obtained relative humidity RHn'; When it is determined that water ingress or condensation has occurred in the battery pack, re-determine the new absolute humidity AHn1’ and the new theoretical absolute humidity AHn2’ in the current environment according to the newly obtained relative humidity RHn' and the wall temperature Tn', and perform airtightness recognition on the battery pack according to the relative magnitude between the new absolute humidity AHn1’ and the second humidity range composed of the new theoretical absolute humidity AHn2’.

4. The power battery monitoring method according to claim 3, wherein The step of performing water ingress or condensation recognition on the battery pack according to the newly obtained relative humidity RHn includes: If the difference between the relative humidity RHn before battery pack heating and the newly obtained relative humidity RHn' is greater than the preset threshold, determine that condensation has occurred in the battery pack; If the difference between the relative humidity RHn before battery pack heating and the newly obtained relative humidity RHn' is less than or equal to the preset threshold, determine that water ingress has occurred in the battery pack.

5. The power battery monitoring method according to claim 3, wherein The steps for identifying the airtightness of the battery pack according to the relative magnitude between the new absolute humidity AHn1’ and the second humidity range formed by the new theoretical absolute humidity AHn2’ include: If the new absolute humidity AHn1’ is within the second humidity range formed by the new theoretical absolute humidity AHn2’, it is determined that the airtightness of the battery pack is normal; If the new absolute humidity AHn1’ is not within the second humidity range formed by the new theoretical absolute humidity AHn2’, it is determined that the airtightness of the battery pack fails.

6. The power battery monitoring method according to claim 3, characterized in that, The steps for detecting the airtightness, condensation, and water ingress of the battery pack according to the relative magnitude relationship between the wall temperature and the dew point temperature, the relative magnitude relationship between the absolute humidity and the absolute humidity reference value, and the relative magnitude relationship between the absolute humidity and the theoretical absolute humidity further include: When the wall temperature Tn is greater than the dew point temperature T0, the airtightness of the battery pack is identified according to the relative magnitude relationship between the absolute humidity AHn and the third humidity range formed by the absolute humidity reference value AH0.

7. The power battery monitoring method according to claim 6, wherein The steps for identifying the airtightness of the battery pack according to the relative magnitude relationship between the absolute humidity AHn and the third humidity range formed by the absolute humidity reference value AH0 include: If the absolute humidity AHn is within the third humidity range 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 range formed by the absolute humidity reference value AH0, it is determined that the airtightness of the battery pack fails.

8. The power battery monitoring method according to claim 2 or 3, characterized in that The battery pack is heated by controlling a humidity sensor with a heating function provided inside the battery pack.

9. The power battery monitoring method according to claim 1, wherein The method further includes: If the explosion-proof valve is currently performing an equalizing air pressure operation, the relative humidity, wall temperature, and real-time pressure inside the battery pack are obtained; If the relative humidity, wall temperature, and real-time pressure inside the battery pack remain balanced within a predetermined time period, the absolute humidity under the current environment is determined according to the relative humidity and wall temperature inside the battery pack re-obtained after balance, and the absolute humidity is updated to a new absolute humidity reference value.

10. The power battery monitoring method according to claim 1, wherein, The steps for performing abnormal handling if at least one of the detection results of the airtightness, condensation, and water ingress of the battery pack is abnormal include: If there is only condensation abnormality and the insulation resistance of the vehicle is not less than the predetermined normal value for a long time, a first prompt for reminding the user to replace the moisture absorbent sheet of the battery pack is output; If there is only condensation abnormality and the insulation resistance of the vehicle is within the preset insulation resistance range for a long time, a second prompt for reminding the user that the vehicle has an insulation risk and the moisture absorbent sheet of the battery pack needs to be replaced and the airtightness needs to be repaired is output; If there is only airtightness abnormality, a third prompt for reminding the user to perform vehicle maintenance and avoid driving in wading sections and rainy weather is output; If there is condensation abnormality and the battery pack has an insulation fault, or the battery pack is flooded, the vehicle use is restricted, the battery high voltage is cut off to prohibit charging and discharging, and the battery fault warning light on the instrument panel is lit.

11. A power battery monitoring method, characterized in that, Applied to the cloud, the method includes: Obtaining the relative humidity and wall temperature inside the battery pack uploaded by the vehicle before powering off; Obtaining the environmental forecast temperature at the location where the vehicle is located; Determine the dew point temperature according to the relative humidity and wall temperature inside the battery pack; If the relative humidity is greater than the preset humidity and the ambient forecast temperature is less than the maximum value of the temperature range composed of the dew point temperature, wake up the vehicle, push a condensation risk warning to the vehicle, and send a control command to heat the battery pack to the vehicle; If it is received that the battery pack does not meet the heating condition feedback from the vehicle, when the real-time ambient temperature is less than the dew point temperature, wake up the vehicle to update the environmental data inside the battery pack.

12. A power battery monitoring device, characterized in that, It includes: A first acquisition module, configured to acquire the current absolute humidity reference value of the vehicle; A real-time parameter acquisition module, configured to acquire the relative humidity and wall temperature inside the battery pack if the explosion-proof valve is not currently performing a balanced air pressure operation; A parameter calculation module, configured to determine the absolute humidity, dew point temperature, and theoretical absolute humidity under the current environment according to the relative humidity and wall temperature inside the battery pack; A detection module, configured to perform airtightness, condensation, and water ingress detection of the battery pack according to the relative magnitude relationship between the wall temperature and the dew point temperature, the relative magnitude relationship between the absolute humidity and the absolute humidity reference value, and the relative magnitude relationship between the absolute humidity and the theoretical absolute humidity; A processing module, configured to perform anomaly processing if at least one of the airtightness, condensation, and water ingress detection results of the battery pack is abnormal.

13. A vehicle, characterized in that, It includes the power battery monitoring device described in claim 12.

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