Battery pack liquid leakage early warning method and system, and electric device

Abstract

The application relates to the technical field of battery monitoring, and provides a battery pack liquid leakage early warning method and system and a power utilization device. The battery pack liquid leakage early warning method comprises the following steps: obtaining the liquid leakage conductivity of the battery pack according to a leakage sampling voltage; obtaining the liquid leakage type of the battery pack according to the liquid leakage conductivity; wherein the liquid leakage type comprises at least one of condensate water, external water, cooling liquid and electrolyte; and performing liquid leakage early warning according to the liquid leakage type. The application can distinguish the liquid leakage type of the battery pack, and accurately judge the property and danger level of the liquid leakage.

Description

Technical Field

[0001] This invention relates to the field of battery monitoring technology, and in particular to a method and system for early warning of battery pack leakage, and an electrical device. Background Technology

[0002] The power battery pack is a key energy supply unit for electrical devices. It contains high-voltage electrical components, individual battery cells, and a liquid cooling piping system for heat dissipation. During operation, the battery pack may experience condensation buildup due to changes in ambient temperature and humidity, coolant leakage due to aging or loose connections in the liquid cooling piping, external water intrusion due to damaged seals, or electrolyte leakage due to damage to individual battery cells.

[0003] Currently, the mainstream solution for detecting internal leakage in power battery packs is continuity-based circuit detection. This method can only determine whether the circuit is conductive to identify the presence of liquid, but it fails to collect continuous electrical signals that reflect the characteristics of the liquid. This makes it difficult for the system to effectively distinguish between liquids with different levels of danger, accurately assess the level of danger, and make differentiated safety responses. This can easily lead to false alarms or failure to implement safety protection in a timely manner. Summary of the Invention

[0004] This invention provides a method and system for early warning of battery pack leakage, as well as an electrical device, which can distinguish the type of battery pack leakage and accurately determine the nature and hazard level of the leakage.

[0005] In a first aspect, embodiments of the present invention provide a method for early warning of leakage in a battery pack, comprising: The leakage conductivity of the battery pack is obtained based on the leakage sampling voltage. The leakage type of the battery pack is determined based on the leakage conductivity; wherein the leakage type includes at least one of condensate, external water ingress, coolant, and electrolyte; Execute a leak warning based on the leak type.

[0006] In some embodiments, obtaining the leakage conductivity of the battery pack based on the leakage sampling voltage includes: The leakage conductivity of the battery pack is obtained based on the difference between the reference voltage and the leakage sampling voltage; wherein the leakage sampling voltage is the voltage division of the reference voltage through the series nodes of the impedance network, and the impedance network includes at least the leakage equivalent resistance and the voltage dividing resistance connected in series.

[0007] In some embodiments, performing a leak warning based on the leak type includes: The leak type is determined to be condensate, and a Level 1 leak warning is issued. If the leakage type is determined to be coolant or external water ingress, a level two leakage restriction warning is executed, which restricts power output and / or pushes leakage information to the interactive terminal; If the leakage type is determined to be electrolyte, a level three emergency leakage warning is issued, prohibiting power output and / or triggering audible and visual alarms.

[0008] In some embodiments, the leakage sampling voltage is multiple leakage sampling voltages corresponding to different sampling areas of the battery pack. Before executing a leakage warning based on the leakage type, the method further includes: The number of leakage current sampling voltages that are greater than or equal to the first threshold is obtained; Obtain the amplitude of change of a single leakage current sampling voltage; Execute a leak warning based on the leak type, including: A leak classification warning is executed based on the quantity and / or the magnitude of the change, as well as the type of leak.

[0009] In some embodiments, a leak classification warning is performed based on the quantity and / or the magnitude of the change, and the type of leak, including: The leakage severity index is obtained based on the quantity and / or the magnitude of change; If the leakage type is determined to be coolant or external water ingress and the leakage severity index is less than the index threshold, a level one leakage warning is issued, or a level two leakage restriction warning is issued, which restricts power output and / or pushes leakage information to the interactive terminal. If the leakage severity index is determined to be greater than or equal to the index threshold and / or the leakage type is electrolyte, a level three emergency leakage warning is issued, power output is prohibited, and / or an audible and visual alarm is triggered.

[0010] In some embodiments, determining the leakage type of the battery pack based on the leakage conductivity includes: Determine if the leakage conductivity is greater than or equal to a second threshold and less than or equal to a third threshold, and obtain the rate of change of the leakage conductivity. If the absolute value of the rate of change is less than or equal to the rate of change threshold, it is determined to be coolant; If the absolute value of the rate of change is greater than the rate of change threshold, it is determined that there is external water inflow.

[0011] In some embodiments, before obtaining the leakage conductivity of the battery pack based on the leakage sampling voltage, the method further includes: The temperature compensation coefficient is obtained based on the ambient temperature. The leakage current sampling voltage is temperature-compensated according to the temperature compensation coefficient. The leakage conductivity of the battery pack is obtained based on the leakage sampling voltage, including: The leakage conductivity of the battery pack is obtained based on the leakage sampling voltage after temperature compensation.

[0012] In some embodiments, the leakage current sampling voltage is multiple leakage current sampling voltages corresponding to different sampling areas of the battery pack, and the method further includes: The leakage location and / or leakage diffusion area are obtained based on the leakage sampling voltage and its corresponding battery pack sampling area.

[0013] Secondly, embodiments of the present invention also provide a battery pack leakage warning system, comprising: A conductivity sensing unit is used to obtain the leakage current sampling voltage; The processor, communicatively connected to the conductive sensing unit, is used to execute the battery pack leakage warning method as described in the first aspect.

[0014] In some embodiments, the conductive sensing unit is located on the liquid accumulation surface within the battery pack. The conductive sensing unit includes a first conductive electrode and a second conductive electrode, which are arranged at intervals, and a deposition gap is left between the ends of the first conductive electrode and the second conductive electrode and the liquid accumulation surface.

[0015] In some embodiments, the spacing between the first conductive electrode and the second conductive electrode ranges from 5 mm to 20 mm, and the deposition gap is less than or equal to 2 mm.

[0016] In some embodiments, the conductive sensing units are multiple and distributed in high-risk busbar areas within the battery pack; wherein, the high-risk busbar areas include at least a high-voltage electrical device central storage area and a liquid-cooled pipe joint area, and the conductive sensing unit arrangement density in the high-voltage electrical device central storage area is greater than the conductive sensing unit arrangement density in the liquid-cooled pipe joint area.

[0017] In some embodiments, the distance between adjacent conductive sensing units is less than or equal to a distance threshold.

[0018] Thirdly, embodiments of the present invention also provide an electrical device, including a battery pack leakage warning system as described in the first aspect, wherein the processor reuses the battery management system of the electrical device.

[0019] This invention improves the detection dimension from on / off state to a continuous quantitative feature reflecting the conductivity of liquids. It can automatically distinguish online four types of liquids with different properties and hazard levels: condensate inside the battery pack, external water ingress, coolant, and electrolyte. This overcomes the limitation of traditional solutions that can only determine whether there is water or not, but cannot determine what kind of liquid is leaking, and provides an accurate basis for the safety protection of battery packs. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0021] Figure 1 This is a schematic flowchart of a battery pack leakage early warning method provided in an embodiment of the present invention; Figure 2 This is a calibration feature mapping diagram of the leakage type, conductivity reference range, and variation range of a battery pack provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of a specific process for a battery pack leakage early warning method provided in an embodiment of the present invention; Figure 4 This is a schematic diagram of the structural installation of a conductive sensing unit on a liquid accumulation surface according to an embodiment of the present invention; Figure 5 This is a top view schematic diagram of the arrangement position of a conductive sensing unit in a high-risk current-carrying area inside a battery pack, according to an embodiment of the present invention. Figure 6 This is an overall structural block diagram of a battery pack leakage warning system provided in an embodiment of the present invention. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0023] Currently, the mainstream technology for detecting internal leakage in power battery packs is the continuity-type leakage sensor. Its working principle involves placing one or more pairs of electrodes, such as conductive wire harnesses, at the bottom of the battery pack. When liquid comes into contact with and bridges the two electrodes, the circuit is completed. The battery management system receives the continuity signal and triggers an alarm. This solution has been applied in some mass-produced vehicles and can achieve basic leakage presence detection. However, the aforementioned technology cannot distinguish between different types of liquids. Existing sensors can only determine whether the circuit is continuous, i.e., they can only identify two states: the presence or absence of liquid. The fundamental reason is that their circuit design only focuses on the on / off signal and does not collect continuous information such as conductivity, which reflects the electrochemical characteristics of the liquid. This results in the inability to distinguish between liquids with vastly different levels of danger, such as condensate, coolant, electrolyte, and external water, such as rainwater or muddy water, and the system cannot assess the actual level of danger.

[0024] To address the aforementioned technical problems, this invention provides a method for early warning of battery pack leakage. Figure 1 This is a schematic flowchart illustrating a battery pack leakage warning method according to an embodiment of the present invention. The battery pack leakage warning method can be executed by the battery pack leakage warning system provided in this embodiment of the present invention. Figure 1 As shown, the battery pack leakage warning method includes the following steps: S101. Obtain the leakage conductivity of the battery pack based on the leakage sampling voltage.

[0025] S102. Obtain the leakage type of the battery pack based on the leakage conductivity; wherein the leakage type includes at least one of condensate, external water ingress, coolant, and electrolyte.

[0026] S103. Execute a leak warning based on the type of leak.

[0027] Specifically, leakage sampling voltage refers to the continuous voltage signal collected by the conductivity sensing unit, reflecting the liquid immersion state and resistance change between the probe or electrode. Battery pack leakage conductivity refers to the numerical characteristic reflecting the liquid conductivity capability of the immersed conductivity sensing unit, calculated based on the leakage sampling voltage. Battery pack leakage type refers to the classification of liquids with different sources and chemical compositions that may appear inside the battery pack, including at least one of condensate, external water ingress, coolant, and electrolyte. Leakage warning refers to outputting corresponding level of safety control and alert commands to the control system, interactive terminal, or alarm actuator of the electrical device based on the identified battery pack leakage type.

[0028] When liquid enters the battery pack and comes into contact with the conductivity sensing unit, a conductive path is formed between the two electrodes of the unit. Because different types of liquids have varying concentrations and types of freely moving ions, each possesses specific conductivity. The processor acquires the leakage sampling voltage output by the conductivity sensing unit at a preset sampling period. Since the leakage sampling voltage has a monotonic relationship with the equivalent resistance of the liquid between the two electrodes, and this equivalent resistance is inversely proportional to the liquid's conductivity, the processor calculates the leakage conductivity of the battery pack based on the leakage sampling voltage using the established voltage-conductivity mapping relationship. Next, the processor compares the battery pack's leakage conductivity with pre-calibrated and stored conductivity reference ranges for various types of liquids to determine whether the liquid currently submerged in the conductivity sensing unit is condensate, external water, coolant, or electrolyte. Finally, based on the determined leakage type of the battery pack, the processor triggers the corresponding leakage warning mechanism.

[0029] Therefore, by elevating the detection dimension from on / off state to a continuous quantitative feature reflecting the conductivity of a liquid, this embodiment of the invention can automatically distinguish online four types of liquids with different properties and hazard levels: condensate inside the battery pack, external water ingress, coolant, and electrolyte. This overcomes the limitation of traditional solutions that can only determine whether there is water or not, but cannot determine what kind of liquid is leaking, and provides an accurate basis for the safety protection of the battery pack.

[0030] In some embodiments, obtaining the leakage conductivity of the battery pack based on the leakage sampling voltage includes: obtaining the leakage conductivity of the battery pack based on the difference between the reference voltage and the leakage sampling voltage; wherein the leakage sampling voltage is the voltage division of the reference voltage through the series nodes of the impedance network, and the impedance network includes at least the leakage equivalent resistance and the voltage division resistance connected in series.

[0031] Specifically, the reference voltage refers to a known constant or controllable excitation voltage applied to the input of the impedance network. The impedance network is a circuit structure consisting of voltage-dividing resistors and the equivalent leakage resistance formed when the liquid is immersed, connected in series. The equivalent leakage resistance refers to the equivalent resistance presented between the first and second conductive electrodes of the conductive sensing unit when the liquid bridges the connection. The voltage-dividing resistor is a fixed-value resistor pre-set in the impedance network and connected in series with the equivalent leakage resistance for voltage division sampling.

[0032] When there is no liquid bridging the conductive sensing unit, the first and second conductive electrodes are in an open-circuit state, resulting in a large leakage equivalent resistance and a leakage sampling voltage close to the reference voltage. When liquid accumulates and bridges the first and second conductive electrodes, a conductive path is formed between the two electrodes, generating a finite leakage equivalent resistance. The impedance network operates on the principle of voltage division. The leakage sampling voltage is the voltage division of the reference voltage at the series node of the impedance network. That is, the reference voltage is input to one end of the impedance network, and the other end of the impedance network can be connected to ground. The impedance includes series voltage dividing resistors, such as pull-up resistors and leakage equivalent resistance. The series node between the two outputs the aforementioned leakage sampling voltage. The processor measures the leakage sampling voltage and calculates the voltage difference between the reference voltage and the leakage sampling voltage. This voltage difference is inversely proportional to the leakage equivalent resistance. Since the leakage conductivity of the liquid battery pack is inversely proportional to the leakage equivalent resistance, the processor uses this voltage difference to calculate the leakage equivalent resistance between the two electrodes, and then calculates the leakage conductivity of the liquid battery pack.

[0033] Therefore, this embodiment of the invention utilizes a voltage divider circuit structure to convert the equivalent resistance of liquid leakage into a leakage sampling voltage signal that is easy to sample. The circuit conversion logic is simple and the signal response is fast. The equivalent resistance and conductivity are converted by the difference between the reference voltage and the leakage sampling voltage, which can effectively reduce the interference of reference voltage fluctuations on the detection results and further improve the accuracy and stability of the leakage conductivity calculation of the battery pack.

[0034] In some embodiments, a leak warning is executed based on the type of leak, including: if the leak type is condensate, a first-level leak alert is executed; if the leak type is coolant or external water ingress, a second-level leak restriction warning is executed, restricting power output and / or pushing leak information to an interactive terminal; if the leak type is electrolyte, a third-level emergency leak warning is executed, prohibiting power output and / or triggering an audible and visual alarm.

[0035] Specifically, a Level 1 leak warning corresponds to a low-risk level, where the system silently logs the warning and does not send a visible alarm signal to the interactive terminal. A Level 2 leak limiting warning corresponds to a medium-risk level, where the system restricts power output and / or sends leak information to the interactive terminal. A Level 3 leak emergency warning corresponds to a high-risk level, where the system disables power output and / or triggers audible and visual alarms. The interactive terminal refers to a display screen or human-machine interface device used to display vehicle and battery pack operating status information to the user or driver.

[0036] The processor compares the calculated leakage conductivity of the battery pack with a preset voltage or conductivity characteristic range. When the leakage conductivity is less than the first conductivity threshold, the leakage type is determined to be condensation. Condensation is a small amount of water accumulated due to changes in ambient temperature and humidity, posing a low risk. The system executes a level one leakage warning, silently logging the fault and not pushing pop-up alarms to the interactive terminal to avoid disturbing the user. When the leakage conductivity is in a medium range, the leakage type is determined to be coolant or external water ingress. These two types of liquids may cause a decrease in insulation performance or component corrosion. The system executes a level two leakage limitation warning, restricting power output and / or pushing leakage information to the interactive terminal. When the leakage conductivity is greater than or equal to the third conductivity threshold, the leakage type is determined to be electrolyte. Electrolyte is corrosive and highly conductive, easily causing high-voltage short circuits and safety accidents. The system immediately executes a level three emergency leakage warning, prohibiting power output and / or triggering audible and visual alarms.

[0037] Therefore, this invention, by establishing a three-level differentiated early warning strategy corresponding to the hazard level of the liquid, changes the coarse-grained response mode of the traditional detection scheme that is either reporting or remaining silent. When faced with harmless condensate, intelligent filtration prevents false alarms, ensuring the normal availability of electrical devices. When faced with medium-hazard coolant or external water, operation is restricted, balancing safety and driving needs. When faced with highly hazardous electrolytes, power output is prohibited, greatly ensuring the safety of electrical devices and personnel.

[0038] Figure 2 This is a calibration feature mapping diagram showing the leakage type, conductivity reference range, and variation range of a battery pack according to an embodiment of the present invention. For example... Figure 2 As shown, the variation range is the difference between the reference voltage and the leakage sampling voltage. The horizontal axis represents the leakage conductivity of the battery pack, and the vertical axis represents the leakage type of the battery pack. For example, Figure 2The system is divided into three danger zones and corresponding threshold lines. The first voltage threshold line ΔV1 corresponds to a conductivity of 0.1 mS / cm. The second voltage threshold line ΔV2 is located within the medium-risk zone. The third voltage threshold line ΔV3 corresponds to a conductivity of 5 mS / cm, representing the boundary between the medium-risk and high-risk zones. When the change is less than the first voltage threshold ΔV1, it is judged as no liquid or normal. When the change is greater than or equal to the first voltage threshold ΔV1 and less than the second voltage threshold ΔV2, it is judged as condensate in the low-risk zone. When the change is greater than or equal to the second voltage threshold ΔV2 and less than the third voltage threshold ΔV3, it is judged as the medium-risk zone. Within this zone, conductivity in the lower range of 0.1 mS / cm to 5 mS / cm is judged as external water ingress, such as rainwater or muddy water. Conductivity in the upper range of 0.5 mS / cm to 2 mS / cm is judged as coolant, such as ethylene glycol aqueous solution. When the change is greater than or equal to the third voltage threshold ΔV3, it is judged as electrolyte in the high-risk zone, such as organic electrolyte.

[0039] In some embodiments, the leakage sampling voltage is multiple leakage sampling voltages corresponding to different sampling areas of the battery pack. Before performing a leakage warning based on the leakage type, the method further includes: obtaining the number of leakage sampling voltages greater than or equal to a first threshold; obtaining the change amplitude of a single leakage sampling voltage; and performing a leakage warning based on the leakage type, including: performing a graded leakage warning based on the number and / or change amplitude, and the leakage type.

[0040] Specifically, the first threshold refers to a pre-set threshold for determining whether liquid bridging or leakage has occurred in a single sampling area. The change amplitude refers to the deviation of the leakage sampling voltage output by a single conductivity sensing unit from the reference voltage. The leakage classification early warning refers to a refined classification early warning mechanism determined by comprehensively considering the type and scale of leakage in the battery pack.

[0041] Multiple sets of conductive sensing units are arranged in different sampling areas inside the battery pack. During the data acquisition process, the processor simultaneously acquires the leakage sampling voltage of each sampling area and calculates the change in voltage relative to a reference voltage. The processor counts the number of leakage sampling voltages with changes greater than or equal to a first threshold, which reflects the diffusion area of ​​the leaking liquid at the bottom of the battery pack. Simultaneously, the processor extracts the change amplitude of individual conductive sensing units; a larger change amplitude indicates a higher thickness of liquid accumulated between the probes in that sampling area. Finally, the processor performs a multi-dimensional comprehensive comparison of the obtained quantity and change amplitude with the previously identified leakage type of the battery pack to perform a graded leakage warning.

[0042] Therefore, this embodiment of the invention, based solely on the type of leakage in the battery pack for early warning, introduces two characteristic quantities that reflect the spatial diffusion area and local liquid accumulation thickness: the number of leakage sampling voltages greater than or equal to a first threshold and the amplitude of change of a single leakage sampling voltage. This enables the system to not only identify what kind of liquid is leaking, but also to assess how much liquid is leaking, achieving a dual assessment of type and quantity, and significantly improving the accuracy of leakage classification and early warning.

[0043] In some embodiments, a graded leak warning is performed based on the quantity and / or magnitude of change, as well as the type of leak, including: obtaining a leak severity index based on the quantity and / or magnitude of change; determining that the leak type is coolant or external water ingress and that the leak severity index is less than the index threshold, and performing a Level 1 leak alert warning, or performing a Level 2 leak restriction warning, restricting power output and / or pushing leak information to an interactive terminal; determining that the leak severity index is greater than or equal to the index threshold and / or the leak type is electrolyte, and performing a Level 3 emergency leak warning, prohibiting power output and / or triggering an audible and visual alarm.

[0044] Specifically, the leakage severity index is a comprehensive value characterizing the severity of a leakage, obtained by weighting the number and variation amplitude of leakage current sampling voltages greater than or equal to a first threshold. The index threshold is the critical value of the leakage severity index used to distinguish between minor and severe leaks.

[0045] The processor calculates a leakage severity index using a preset algorithm based on the acquired quantity and magnitude of change. The processor then inputs the battery pack leakage type and the leakage severity index into a decision matrix. If the leakage type is determined to be coolant or external water ingress, and the calculated leakage severity index is less than the threshold, it indicates a minor leak. The system executes a Level 1 leakage warning or a Level 2 leakage restriction warning, limiting power output and / or pushing leakage information to the interactive terminal to ensure continued operation of the electrical device. If the leakage severity index is greater than or equal to the preset threshold, it indicates a large-scale leak. The system escalates the warning level to a Level 3 emergency leakage warning, prohibiting power output and / or triggering audible and visual alarms. For cases where the battery pack leakage type is electrolyte, due to its inherent high risk, the system executes a Level 3 emergency leakage warning regardless of the leakage severity index.

[0046] This invention, through establishing a decision-making logic that combines leakage type with a leakage severity index, avoids simply cutting off power for moderately hazardous liquids. It allows for power-limited operation during minor coolant leaks and promptly disables power output during large-area leaks, making the vehicle's safety protection actions more rational and further balancing the safety protection and operational continuity of the electrical system. Thus, a leakage severity index is formed by combining these two dimensions, which, along with the battery pack leakage type, serves as the basis for leak classification and early warning. Specifically, the severity of the leak is assessed through the following two dimensions: Dimension 1 is the number of leakage sampling voltages greater than or equal to a first threshold. For example, the more conductive sensing units that trigger the threshold at the same time, the larger the leakage diffusion area and the higher the leakage amount. Dimension 2 is the amplitude of change in a single leakage sampling voltage. For example, under the same leakage type, a larger amplitude of change indicates a higher liquid accumulation thickness between electrodes and a greater local leakage amount.

[0047] In some embodiments, determining the leakage type of the battery pack based on the leakage conductivity includes: determining that the leakage conductivity is greater than or equal to a second threshold and less than or equal to a third threshold, and obtaining the rate of change of the leakage conductivity; determining that the absolute value of the rate of change is less than or equal to the rate of change threshold, and determining it to be coolant; determining that the absolute value of the rate of change is greater than the rate of change threshold, and determining it to be external water ingress.

[0048] Specifically, the second and third thresholds refer to the pre-set lower and upper limits of conductivity thresholds used to define the conductivity distribution range of the coolant and external influent. The rate of change of leakage conductivity refers to the amplitude or rate of change of the leakage conductivity over multiple consecutive sampling periods. The rate of change threshold is the critical value used to distinguish between homogeneous liquids and heterogeneous suspensions.

[0049] Referring to the aforementioned embodiment, the conductivity of externally ingressed water is in the range of 0.1 mS / cm to 5 mS / cm, while the conductivity of the coolant is in the range of 0.5 mS / cm to 2 mS / cm. There is some overlap in the conductivity distribution ranges of externally ingressed water and the coolant. When the calculated leakage conductivity of the battery pack is greater than or equal to a second threshold (e.g., 0.1 mS / cm) and less than or equal to a third threshold (e.g., 5 mS / cm), the processor initiates a time-domain dynamic analysis mechanism to continuously record the leakage conductivity over multiple sampling periods and calculate its rate of change over time. If the absolute value of the rate of change is less than or equal to the rate of change threshold, the processor determines it to be coolant because the coolant is a homogeneous solution with stable conductivity. However, externally ingressed water contains particles and suspended matter, and its conductivity fluctuates during liquid flow and vibration of the electrical device. If the absolute value of the rate of change is greater than the rate of change threshold, the processor determines it to be externally ingressed water. In addition, as an alternative implementation, when the leakage conductivity of the battery pack falls into the overlapping area, the processor can control the signal injection module to inject two weak AC excitation signals of different frequencies, such as 100 Hz and 10 kHz, into the conductivity sensing unit, and measure the complex impedance between the two electrodes. By utilizing the dielectric relaxation characteristics and high-low frequency impedance ratio unique to the coolant polymer solution, it can be accurately distinguished from external water ingress, which exhibits pure resistive characteristics.

[0050] Therefore, by introducing the dynamic time-domain feature of the rate of change of leakage conductivity, the embodiments of the present invention eliminate the identification confusion caused by the overlap of static conductivity values, ensuring that even when the conductivity values ​​are similar, the coolant and external water ingress can still be accurately distinguished, further improving the reliability of leakage type identification of the battery pack.

[0051] In some embodiments, before obtaining the leakage conductivity of the battery pack based on the leakage sampling voltage, the method further includes: obtaining a temperature compensation coefficient based on the ambient temperature; performing temperature compensation on the leakage sampling voltage based on the temperature compensation coefficient; and obtaining the leakage conductivity of the battery pack based on the leakage sampling voltage, which includes: obtaining the leakage conductivity of the battery pack based on the temperature-compensated leakage sampling voltage.

[0052] Specifically, the temperature compensation coefficient is a correction coefficient pre-set based on the law of liquid conductivity change with temperature, used to normalize the sampling voltage at non-standard temperatures to that at standard temperatures. Liquid conductivity is temperature-sensitive; changes in ambient temperature cause a shift in liquid conductivity. Before sampling, the processor reads the ambient temperature associated with the inside of the battery pack and obtains the corresponding temperature compensation coefficient based on the pre-stored relationship between temperature and temperature compensation coefficient. Subsequently, the processor uses this temperature compensation coefficient to perform temperature compensation on the originally acquired leakage sampling voltage. Finally, based on the temperature-compensated leakage sampling voltage, the leakage conductivity of the battery pack is calculated, and then the leakage type of the battery pack is identified.

[0053] Therefore, this invention eliminates conductivity measurement drift caused by temperature changes across the entire operating temperature range of the battery pack. This avoids misidentifying coolant as condensate due to low conductivity at low temperatures, or misidentifying coolant as electrolyte due to high conductivity at high temperatures, further improving the system's early warning accuracy under different ambient temperature conditions. For example, liquid conductivity increases with temperature, for instance, by 1% to 3% for every 1 degree Celsius increase. Low temperatures may lead to misjudgment of battery pack leakage types. Based on the aforementioned embodiments, a temperature sensor is added, such as reusing an existing negative temperature coefficient temperature sensor in the battery management system. A temperature compensation coefficient is introduced into the calibration algorithm, and the leakage sampling voltage is normalized before performing battery pack leakage type identification, improving the identification accuracy across the entire temperature range, for example, from -40 degrees Celsius to 85 degrees Celsius.

[0054] In some embodiments, the leakage sampling voltage is multiple leakage sampling voltages corresponding to different sampling areas of the battery pack, and the method further includes: obtaining the leakage location and / or leakage diffusion area based on the leakage sampling voltage and its corresponding battery pack sampling area.

[0055] Specifically, the leak location refers to the two-dimensional spatial coordinates of the leak source or the center of liquid accumulation, calculated from the coordinates of multiple sampling areas. The leak diffusion area refers to the liquid coverage area calculated based on the number of sampling areas that trigger the sampling threshold and the grid distribution. Multiple conductive sensing units with sampling areas are arranged inside the battery pack, and the physical coordinates of each sampling area are pre-stored in the processor. When a leak occurs, the conductive sensing units in different sampling areas output different leakage sampling voltages. The processor extracts all sampling areas whose amplitudes exceed the threshold, and uses their respective amplitudes or conductivity as weights to calculate the leak location using a centroid-weighted algorithm. Simultaneously, the processor multiplies the number of sampling areas that trigger the threshold by the area of ​​a single grid cell to calculate the leak diffusion area. Furthermore, the reference voltage applied to the impedance network can be driven by a high-frequency polarity reversal pulse signal or a pulse-width modulated AC excitation signal to eliminate the electrode polarization effect and electrolytic erosion loss of the conductive sensing units in the conductive liquid. When the leakage type of the battery pack is identified as condensation, the processor can briefly switch the pin of the conductivity sensing unit to a high-current heating mode for self-heating and dehydration. If the leakage sampling voltage returns to the open circuit state before immersion after a preset heating time, the system will automatically reset and confirm that the fault has been eliminated. If the voltage remains unchanged, the judgment will be corrected to a continuous external leakage.

[0056] Therefore, this invention not only identifies the type of battery pack leakage but also provides the leakage location and leakage diffusion area. This provides after-sales maintenance personnel with a clear direction for troubleshooting, enabling rapid location of the leakage source and significantly shortening troubleshooting and repair time. For example, multiple pairs of conductive electrodes can be arranged in a two-dimensional array in a matrix on a liquid accumulation surface, such as a liquid cooling plate area. Simultaneously, the leakage sampling voltage response of each array node is detected. Based on the spatial distribution of the response nodes, the leakage location and leakage diffusion area can be calculated. This not only determines whether there is a leak and what type of leak it is but also outputs the leak location coordinates, providing location information for maintenance personnel and shortening after-sales troubleshooting time.

[0057] Figure 3 This is a schematic flowchart illustrating a battery pack leakage warning method provided in an embodiment of the present invention. Figure 3 As shown, the battery pack leakage warning method includes the following steps: S201, Begin.

[0058] S202, The processor reads the leakage current sampling voltage of each conductive sensing unit.

[0059] For example, the processor may read the leakage current sampling voltage of each conductive sensing unit at a sampling period of 100 milliseconds to 1 second.

[0060] S203. Calculate the change relative to the reference voltage.

[0061] Specifically, this involves calculating the magnitude of the change relative to the reference voltage Vref, ΔV = Vref - Vsensor.

[0062] S204. Determine whether ΔV is less than the first voltage threshold ΔV1. If yes, proceed to S205; otherwise, proceed to S206.

[0063] S205. Condensate or no leakage is determined to be in a low-risk state.

[0064] For example, a Level 1 leak warning can be implemented, which may include silently logging the fault log by the battery management system and then continuing to sample.

[0065] S206. Determine whether ΔV is less than the third voltage threshold ΔV3. If yes, proceed to S207; otherwise, proceed to S208.

[0066] S207. Coolant or external water ingress is determined to be in a medium-risk condition.

[0067] For example, the number of leakage sampling voltages greater than or equal to a first threshold is counted, and a secondary leakage limit warning is executed. The secondary leakage limit warning may include, for example, pushing an alarm to an interactive terminal, limiting power output and recording a fault snapshot, and then continuing sampling.

[0068] S208. Electrolyte leakage is classified as a high-risk condition.

[0069] Specifically, a Level 3 emergency leak warning was immediately issued, instructing the main circuit relay to disconnect, triggering an audible and visual alarm, and reporting to the cloud, followed by continued sampling.

[0070] S209, Continue sampling.

[0071] In summary, the battery pack leakage warning method, also known as the battery management system calibration algorithm, has its core algorithm integrated into the processor software of the battery management system in the multiplexed power device, requiring no additional hardware processor. The algorithm includes the following modules: First, a signal acquisition module. The battery management system reads the leakage sampling voltage between the electrodes of each conductive sensing unit at a fixed sampling period, configurable from 100 milliseconds to 1 second. The impedance network circuit uses the voltage divider principle, applying a constant excitation voltage as a reference voltage, measuring the voltage at the voltage divider node as the leakage sampling voltage, and calculating the equivalent resistance of leakage between the electrodes. When there is no liquid, the electrodes exhibit high resistance, such as in an open circuit state, and the leakage sampling voltage is approximately the reference voltage. After liquid bridging, the leakage sampling voltage V_sensor decreases as the battery pack's leakage conductivity increases. The second is the liquid type identification module. Based on the differences in conductivity among various liquids, four types of target liquids are pre-calibrated in the laboratory to establish a mapping table between the variation range and the leakage type of the battery pack. For details, please refer to the description in the aforementioned embodiment. The specific values ​​of the first voltage threshold ΔV1, the second voltage threshold ΔV2, and the third voltage threshold ΔV3 are determined by laboratory calibration before shipment and stored in the non-volatile memory of the battery management system. The conductivity ranges of external water ingress and coolant partially overlap, which can be differentiated by the rate of change of the battery pack's leakage conductivity, such as stability.

[0072] This invention also provides a battery pack leakage warning system, including: a conductive sensing unit for obtaining leakage sampling voltage; and a processor communicatively connected to the conductive sensing unit for executing the battery pack leakage warning method as described in the foregoing embodiments.

[0073] Specifically, the conductivity sensing unit refers to a hardware sensing component installed inside the battery pack, used to contact liquid and obtain leakage current sampling voltage. The processor refers to a microprocessor or controller circuit with data acquisition, arithmetic logic operations, control command output, and communication functions. The conductivity sensing units are distributed within the battery pack, and their output terminals are connected to the processor's acquisition interface. When liquid accumulates at the conductivity sensing unit, the unit obtains the leakage current sampling voltage. The processor periodically reads the leakage current sampling voltage through the acquisition interface and sequentially executes steps such as arithmetic conversion, type identification, severity assessment, and warning command output in the battery pack leakage early warning method described in the foregoing embodiments.

[0074] Figure 4 This is a schematic diagram illustrating the structural installation of a conductive sensing unit on a liquid accumulation surface, according to an embodiment of the present invention. Figure 4 As shown, the conductive sensing unit 10 is located on the liquid accumulation surface 13 inside the battery pack. The conductive sensing unit 10 includes a first conductive electrode 11 and a second conductive electrode 12. The first conductive electrode 11 and the second conductive electrode 12 are arranged at intervals, and a deposition gap d2 is left between the ends of the first conductive electrode 11 and the second conductive electrode 12 and the liquid accumulation surface 13.

[0075] Specifically, the liquid accumulation surface 13 refers to the structural surface located at the bottom of the battery pack, where leaked liquid naturally converges due to gravity. The first conductive electrode 11 and the second conductive electrode 12 refer to the two non-contacting corrosion-resistant electrodes that constitute the sensing core of the conductive sensing unit 10. The deposition gap d2 refers to the vertical overhang between the ends of the first conductive electrode 11 and the second conductive electrode 12 and the liquid accumulation surface 13.

[0076] The conductive sensing unit 10 is located on the liquid accumulation surface 13 within the battery pack, such as the surface of the liquid cooling plate 14. The first conductive electrode 11 and the second conductive electrode 12 are fixed by an insulating structure and arranged at intervals. The ends of the first conductive electrode 11 and the second conductive electrode 12 do not directly contact the liquid accumulation surface 13, but are separated by a predetermined deposition gap d2. When leakage occurs, the liquid, under the influence of gravity, converges along the plate surface or flow channel to the liquid accumulation surface 13. As the liquid accumulation increases, when the liquid height exceeds the deposition gap d2, the liquid simultaneously contacts and bridges the ends of the first conductive electrode 11 and the second conductive electrode 12, forming a conductive path and generating a leakage sampling voltage.

[0077] As an alternative embodiment, in addition to two needle-shaped metal probes, the conductive sensing unit 10 can also employ comb-shaped or mesh-shaped electrodes printed on a flexible circuit board, conductive tapes with interlaced metal wires, or coaxial metal electrodes. The liquid accumulation surface 13 can be selected as the surface of the liquid cooling plate 14, the bottom groove of the battery pack housing, the bottom of the gap between battery modules, or the water collection tray below the pipeline. The liquid accumulation depression can be determined by three-dimensional fluid simulation of the gravity field of the battery pack under inclined conditions, fluorescence observation on the experimental platform, or by combining mechanical structure physical positioning. In addition, micron-level capillary drainage grooves can be stamped on the surface of the liquid cooling plate 14 at the probe gap, and a hydrophilic layer can be coated around the probes, while a hydrophobic layer can be coated in the remaining area, using capillary adsorption force to quickly pull and concentrate the trace amount of liquid into the deposition gap d2.

[0078] Therefore, this embodiment of the invention utilizes the liquid accumulation surface 13 as the substrate for liquid convergence, combined with the suspended deposition gap d2, enabling the leaked liquid to bridge the electrode and trigger detection even when it accumulates in minute quantities, thus achieving early and agile detection of leaks. (Refer to...) Figure 4 The embodiments of the present invention adopt a standard conductivity dual-electrode scheme, with two needle-shaped electrodes directly connected to the processor of the battery management system, which is suitable for cost-sensitive applications. The conductivity sensing unit 10 has a simple structure and is fully compatible with the existing battery management system hardware interface. Only a software upgrade is needed to realize the leakage type identification function of the battery pack.

[0079] In some embodiments, the distance d1 between the first conductive electrode 11 and the second conductive electrode 12 ranges from 5 mm to 20 mm, and the deposition gap d2 is less than or equal to 2 mm.

[0080] Specifically, the spacing d1 refers to the closest horizontal distance between the first conductive electrode 11 and the second conductive electrode 12. The spacing d1 between the first conductive electrode 11 and the second conductive electrode 12 is set to a range of 5 mm to 20 mm. If the spacing d1 is less than 5 mm, in a high-humidity environment inside the battery pack or in the presence of aerosols, a small water film can easily cause false conductivity between the two electrodes. If the spacing d1 is greater than 20 mm, a larger amount of liquid needs to accumulate to bridge the two electrodes simultaneously, reducing the detection sensitivity. The deposition gap d2 is set to be less than or equal to 2 mm. When the liquid accumulation height reaches 2 mm, the liquid can bridge the two electrodes.

[0081] Therefore, the embodiments of the present invention achieve a good balance between suppressing moisture or aerosol mis-detection and maintaining high detection sensitivity by combining the electrode spacing d1 of 5 mm to 20 mm and the deposition gap d2 of less than or equal to 2 mm, thereby further improving the reliability of detection.

[0082] The following provides specific examples and combinations Figure 4 The structural mounting of the conductive sensing unit 10 on the liquid accumulation surface 13 is described in detail below: The conductive sensing unit 10 consists of two needle-shaped metal probes, such as a first conductive electrode 11 and a second conductive electrode 12. The electrode material is a corrosion-resistant metal, such as stainless steel or titanium alloy, selected according to the specific requirements of electrolyte corrosivity to ensure long-term stable operation in corrosive liquid environments such as electrolytes. The horizontal distance d1 between the first conductive electrode 11 and the second conductive electrode 12 is approximately 10 mm. The conductive sensing unit 10 is mounted on the liquid accumulation surface 13, such as the upper surface of the liquid cooling plate 14. The deposition gap d2 between the lower end of the electrode and the upper surface of the liquid cooling plate 14 is less than or equal to 2 mm. This design utilizes the liquid cooling plate 14 as a physical depression surface for liquid accumulation, ensuring that leaked liquid converges towards the liquid cooling plate 14 under gravity. The conductive sensing unit 10 can generate an identifiable leakage sampling voltage even when a small amount of liquid accumulates. The electrode assembly is fixed to the housing by an insulating bracket 15, and the wires are arranged along the internal wiring harness of the battery pack to the sampling interface of the battery management system.

[0083] Figure 5 This is a top view schematic diagram illustrating the arrangement of a conductive sensing unit in a high-risk current-carrying area inside a battery pack, according to an embodiment of the present invention. Combined with... Figure 4 and Figure 5 The conductive sensing units 10 are multiple and distributed in high-risk busbar areas within the battery pack; wherein, the high-risk busbar areas include at least the high-voltage electrical device centralized storage area A1 and the liquid cooling pipe joint area A2, and the arrangement density of conductive sensing units 10 in the high-voltage electrical device centralized storage area A1 is greater than the arrangement density of conductive sensing units 10 in the liquid cooling pipe joint area A2.

[0084] Specifically, the high-risk convergence area refers to the key monitoring area inside the battery pack where liquid leakage is likely to occur or where leakage could lead to serious safety consequences. The high-voltage electrical component centralized storage area A1 refers to the enclosure area containing high-voltage components such as relays, fuses, connectors, and control motherboards. The liquid-cooled pipe joint area A2 refers to areas prone to leakage, such as inlet / outlet water pipe joints, quick-connect fittings, and pipe bends. The arrangement density refers to the number of conductive sensing units 10 installed per unit surface area. The system adopts a zone-priority arrangement strategy. The high-voltage electrical component centralized storage area A1 contains high-voltage terminals, which are highly susceptible to insulation failure or short circuits upon contact with liquid, posing a significant hazard. The liquid-cooled pipe joint area A2 is a high-risk area for coolant leakage. The processor controls the arrangement density of conductive sensing units 10 to be higher in the high-voltage electrical component centralized storage area A1, maintains a slightly higher density in the liquid-cooled pipe joint area A2, and eliminates or reduces the arrangement density in the flat liquid-cooled plate area 14 without joints.

[0085] Therefore, the partitioned priority layout strategy for high-risk areas in this embodiment of the invention avoids blindly covering the entire area, achieving high coverage of key high-risk areas inside the battery pack with a limited number of conductive sensing units 10, thus reducing system hardware costs and wiring complexity. For example, as... Figure 5 As shown, the bottom of the battery pack includes the upper surface area of ​​the liquid cooling plate 14, which is divided into a high-voltage electrical component centralized compartment area A1 and a liquid cooling pipe joint area A2. To achieve a leakage detection coverage rate of greater than or equal to 90% in key areas inside the battery pack, a multi-conductive sensing unit 10-area regional arrangement strategy is adopted, focusing on covering the following two types of high-risk convergence areas: The first high-risk convergence area is the high-voltage electrical component centralized compartment area A1. For example, a first conductive sensing unit group 50 can be set up for the corresponding electrical compartment, including, for example, a first sensing unit 10a, a second sensing unit 10b, and a third sensing unit 10c. The high-voltage electrical component centralized compartment area A1 centrally houses high-voltage electrical components such as main positive relays, main negative relays, pre-charge relays, fuses, high-voltage connectors, and the battery management system mainboard. Once leakage occurs in this area, the liquid may cause high-voltage insulation failure, such as causing leakage or short circuit, or corrosion of relay terminals and connector terminals, such as causing high-voltage circuit abnormalities. In addition, the number of conductive sensing units 10 should be determined according to the compartment area to ensure coverage of the main low-lying points of the liquid cooling plate 14 in this area. The second high-risk convergence area is the liquid cooling pipe joint area A2. For example, a second conductive sensing unit group 60 can be set for the corresponding pipe joint, including, for example, a fourth sensing unit 10d and a fifth sensing unit 10e. The inlet and outlet joints of the liquid cooling pipe, pipe bends, quick-connect fittings, etc., are high-risk points for coolant leakage. By arranging conductive sensing units 10 on the downstream side of the liquid cooling plate 14 in these areas, early detection of coolant leakage can be achieved. Further, the conductive sensing units 10 should be installed at the lowest point where the liquid naturally converges on the upper surface of the liquid cooling plate 14 in each area. For example, considering the slope of the plate surface and the design of the liquid-blocking ribs, the spacing between adjacent conductive sensing units 10 should ensure that a conductive sensing unit 10 responds in any direction of leakage diffusion, avoiding blind spots.

[0086] In some embodiments, the distance between adjacent conductive sensing units 10 is less than or equal to a distance threshold.

[0087] Specifically, the distance threshold refers to the maximum allowable straight-line distance between two adjacent conductive sensing units 10. Based on the fluid diffusion characteristics at the bottom of the battery pack, a distance threshold between adjacent conductive sensing units 10 is preset. The distance between adjacent conductive sensing units 10 is controlled within a range less than or equal to the distance threshold. When leaked liquid occurs from any point and spreads in all directions, it will inevitably touch and bridge at least one set of conductive sensing units 10 before spreading to the unmonitored area.

[0088] Therefore, this embodiment of the invention further limits the installation spacing of adjacent conductive sensing units 10, eliminates the detection blind zone at the bottom of the battery pack, ensures that the sensor responds when the leakage spreads in any direction, and guarantees no dead-angle coverage of leakage detection.

[0089] Figure 6 This is an overall structural block diagram of a battery pack leakage warning system provided in an embodiment of the present invention. Figure 6 As shown, the battery management system of the processor multiplexes the power consumption device. The array of electrical sensing units is arranged in the key area inside the battery pack. It includes a first conductive sensing unit group 50 located in the high-voltage electrical device centralized compartment area A1, such as a first conductive sensing unit, a second conductive sensing unit and a third backup conductive sensing unit, and a second conductive sensing unit group 60 located in the liquid cooling pipe joint area A2, such as a fourth conductive sensing unit, a fifth conductive sensing unit and a sixth backup conductive sensing unit. Each conductive sensing unit is connected to the sampling interface of the battery management system, such as an analog-to-digital conversion interface, through wires. The processor software layer of the battery management system integrates a signal acquisition module, a liquid type identification module, a leakage assessment module, and a graded prediction output module. The signal acquisition module reads the leakage sampling voltage at a fixed sampling period of 100 milliseconds to 1 second. The liquid type identification module calculates the leakage conductivity of the battery pack based on the leakage sampling voltage and maps it to the leakage type of the battery pack. The leakage assessment module calculates the leakage severity index by combining the number of leakage sampling voltages greater than or equal to a first threshold and the change amplitude of a single leakage sampling voltage. The graded prediction output module outputs early warning commands to the execution terminal, including outputting alarms to the human-machine interaction terminal, sending a command to limit power output to the vehicle controller, and controlling the main circuit relay to disconnect and triggering audible and visual alarms and cloud reporting.

[0090] This invention also provides an electrical device, including a battery pack leakage warning system as described in the foregoing embodiments, and a battery management system for the processor-reused electrical device.

[0091] Specifically, an electrical device refers to a terminal device that uses a battery pack as its energy source. This can be, for example, a vehicle, or a robot, a person- or cargo-carrying device, etc. The battery management system (BMS) is the main control unit within the electrical device used to monitor and manage the battery pack's status, such as voltage, temperature, and charge level. The battery pack's leakage warning system is integrated into the electrical device. Its processor directly reuses the microprocessor of the electrical device's BMS. The output of the conductivity sensing unit is directly connected to the existing sampling interface of the BMS. The leakage detection and warning algorithm runs directly within the BMS as a software function module, eliminating the need for a separate leakage detection controller circuit.

[0092] Therefore, the embodiments of the present invention fully utilize the existing battery management system computing resources and sampling interfaces of the power-consuming device, achieving zero hardware incremental cost. It can realize online identification and graded early warning functions for different liquid types simply by deploying software algorithms, and has good engineering implementation and promotion value.

[0093] In summary, compared with existing technologies, the embodiments of this invention have the following beneficial effects in terms of leakage detection principle, algorithm architecture, and system integration: First, it identifies leakage types in battery packs based on continuous conductivity, upgrading the dimension of leakage detection from a binary on / off state to a continuous conductivity quantity. This enables online automatic differentiation of four types of liquids—condensate, coolant, electrolyte, and external water—within the power battery pack, solving the deficiency of existing technologies in being unable to identify the type of leaking liquid. Second, it employs a dual-dimensional joint early warning model for battery pack leakage type and leakage amount. This model integrates the leakage type (e.g., determined by the magnitude of change) and the leakage amount (e.g., evaluated by the number and magnitude of leakage sampling voltages greater than or equal to a first threshold) into a two-dimensional early warning judgment matrix, making early warning classification more accurate and the vehicle protection response more reasonable. Third, it features a three-level differentiated early warning and refined vehicle response. A three-level leakage early warning output strategy is designed, strictly corresponding to the liquid hazard level. Each level corresponds to a clear power restriction or safety protection action, changing the coarse-grained response mode of existing technologies and balancing safety and usability. Fourth, a liquid-cooled plate with a deposition gap of less than or equal to 2 mm is installed close to the battery pack. By controlling the deposition gap at the lower end of the electrode to be less than or equal to 2 mm, the liquid-cooled plate serves as a natural convergence surface for leakage at the bottom of the battery pack, achieving a detection threshold of 100 ml to 500 ml, enabling early detection of leaks. Fifth, a zoned priority deployment strategy for high-risk convergence areas is proposed, prioritizing the deployment in two high-risk areas: the high-voltage electrical device concentration area and the liquid-cooled pipe joint area. This achieves a coverage rate of greater than or equal to 90% with a limited number of conductive sensing units. Sixth, the battery management system software is integrated, directly integrating the liquid identification and calibration algorithm into the battery management system software layer, reusing existing sampling interfaces of the battery management system, such as analog-to-digital conversion interfaces, without the need for additional independent signal processing hardware. Seventh, a condensate filtering mechanism reduces false alarms. Extremely low conductivity signals are identified as condensate and assigned as a first-level leak warning, for example, without issuing a visible alarm, achieving intelligent filtering of condensate accumulation under normal operating conditions.

[0094] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for early warning of battery pack leakage, characterized in that, include: The leakage conductivity of the battery pack is obtained based on the leakage sampling voltage. The leakage type of the battery pack is determined based on the leakage conductivity; wherein the leakage type includes at least one of condensate, external water ingress, coolant, and electrolyte; Execute a leak warning based on the leak type.

2. The battery pack leakage early warning method according to claim 1, characterized in that, The leakage conductivity of the battery pack is obtained based on the leakage sampling voltage, including: The leakage conductivity of the battery pack is obtained based on the difference between the reference voltage and the leakage sampling voltage; wherein the leakage sampling voltage is the voltage division of the reference voltage through the series nodes of the impedance network, and the impedance network includes at least the leakage equivalent resistance and the voltage dividing resistance connected in series.

3. The battery pack leakage early warning method according to claim 1 or 2, characterized in that, Execute a leak warning based on the leak type, including: The leak type is determined to be condensate, and a Level 1 leak warning is issued. If the leakage type is determined to be coolant or external water ingress, a level two leakage restriction warning is executed, which restricts power output and / or pushes leakage information to the interactive terminal; If the leakage type is determined to be electrolyte, a level three emergency leakage warning is issued, prohibiting power output and / or triggering audible and visual alarms.

4. The battery pack leakage early warning method according to claim 1, characterized in that, The leakage sampling voltage consists of multiple leakage sampling voltages corresponding to different sampling areas of the battery pack. Before executing a leakage warning based on the leakage type, the method further includes: The number of leakage current sampling voltages that are greater than or equal to the first threshold is obtained; Obtain the amplitude of change of a single leakage current sampling voltage; Execute a leak warning based on the leak type, including: A leak classification warning is executed based on the quantity and / or the magnitude of the change, as well as the type of leak.

5. The battery pack leakage early warning method according to claim 4, characterized in that, Based on the quantity and / or the magnitude of change, and the type of leakage, a leakage classification warning is executed, including: The leakage severity index is obtained based on the quantity and / or the magnitude of change; If the leakage type is determined to be coolant or external water ingress and the leakage severity index is less than the index threshold, a level one leakage warning is issued, or a level two leakage restriction warning is issued, which restricts power output and / or pushes leakage information to the interactive terminal. If the leakage severity index is determined to be greater than or equal to the index threshold and / or the leakage type is electrolyte, a level three emergency leakage warning is issued, power output is prohibited, and / or an audible and visual alarm is triggered.

6. The battery pack leakage early warning method according to any one of claims 1-5, characterized in that, The leakage type of the battery pack is determined based on the leakage conductivity, including: Determine if the leakage conductivity is greater than or equal to a second threshold and less than or equal to a third threshold, and obtain the rate of change of the leakage conductivity. If the absolute value of the rate of change is less than or equal to the rate of change threshold, it is determined to be coolant; If the absolute value of the rate of change is greater than the rate of change threshold, it is determined that there is external water inflow.

7. The battery pack leakage early warning method according to any one of claims 1-6, characterized in that, Before obtaining the leakage conductivity of the battery pack based on the leakage sampling voltage, the following steps are also included: The temperature compensation coefficient is obtained based on the ambient temperature. The leakage current sampling voltage is temperature-compensated according to the temperature compensation coefficient. The leakage conductivity of the battery pack is obtained based on the leakage sampling voltage, including: The leakage conductivity of the battery pack is obtained based on the leakage sampling voltage after temperature compensation.

8. The battery pack leakage warning method according to any one of claims 1-7, characterized in that, The leakage current sampling voltage is multiple leakage current sampling voltages corresponding to different sampling areas of the battery pack, and the method further includes: The leakage location and / or leakage diffusion area are obtained based on the leakage sampling voltage and its corresponding battery pack sampling area.

9. A battery pack leakage warning system, characterized in that, include: A conductivity sensing unit is used to obtain the leakage current sampling voltage; The processor is communicatively connected to the conductive sensing unit and is used to execute the battery pack leakage warning method as described in any one of claims 1-8.

10. The battery pack leakage warning system according to claim 9, characterized in that, The conductive sensing unit is located on the liquid accumulation surface inside the battery pack. The conductive sensing unit includes a first conductive electrode and a second conductive electrode, which are arranged at intervals, and a deposition gap is left between the ends of the first conductive electrode and the second conductive electrode and the liquid accumulation surface.

11. The battery pack leakage warning system according to claim 10, characterized in that, The distance between the first conductive electrode and the second conductive electrode ranges from 5 mm to 20 mm, and the deposition gap is less than or equal to 2 mm.

12. The battery pack leakage warning system according to any one of claims 9-11, characterized in that, The conductive sensing units are multiple and distributed in high-risk current-collecting areas within the battery pack; wherein, the high-risk current-collecting areas include at least a high-voltage electrical device centralized storage area and a liquid-cooled pipe joint area, and the conductive sensing unit arrangement density in the high-voltage electrical device centralized storage area is greater than the conductive sensing unit arrangement density in the liquid-cooled pipe joint area.

13. The battery pack leakage warning system according to claim 12, characterized in that, The distance between adjacent conductive sensing units is less than or equal to a distance threshold.

14. An electrical appliance, characterized in that, The system includes a leakage warning system for a battery pack as described in any one of claims 9-13, wherein the processor reuses the battery management system of the power-consuming device.

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