Battery liquid leakage detection circuit, battery liquid leakage monitoring system and method, and traction battery system

Abstract

A battery liquid leakage detection circuit, a battery liquid leakage monitoring system and method, and a traction battery system. The battery liquid leakage monitoring system comprises: a battery management system, a liquid discharge valve and a battery liquid leakage detection circuit, wherein the battery liquid leakage detection circuit is used for reporting, to the battery management system and when a leaked liquid is detected in a battery, a first resistance value formed between a first probe and a second probe; the battery management system is used for sending an opening instruction to the liquid discharge value when the acquired first resistance value is less than a preset first resistance threshold; and the liquid discharge valve is used for opening a valve body on the basis of the opening instruction, and discharging the leaked liquid in the battery. The battery liquid leakage monitoring system may perform, on the basis of the first probe and second probe of the battery liquid leakage detection circuit and in a timely manner, detection on whether liquid leakage occurs in a battery, and when liquid leakage occurs, control, on the basis of a change in a resistance value between the first probe and the second probe and in a timely manner, the liquid discharge valve to discharge a liquid, so as to reduce the possibility of danger occurring in the battery.

Description

Battery leakage detection circuit, monitoring system, monitoring method and power battery system

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on April 1, 2024, with application number 202410390785.1 and invention name “Battery leakage detection circuit, monitoring system, monitoring method and power battery system”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the technical field of power batteries, and in particular to a battery leakage detection circuit, a monitoring system, a monitoring method, and a power battery system. Background Art

[0003] As new energy vehicles become increasingly popular, their safety is drawing increasing attention. As the sole power source for new energy vehicles, the performance and service life of power batteries directly impact the performance and service life of the entire vehicle.

[0004] Currently, insulation testing is used to determine whether a battery system has a performance fault. During the process of the insulation test resistance dropping to the alarm value, the battery may have leaked, short-circuited, or may have become dangerous, resulting in a delay in battery fault detection. Technical issues

[0005] In view of the above problems, the present application provides a battery leakage detection circuit, a monitoring system, a monitoring method and a power battery system. Technical Solutions

[0006] The technical solution adopted in this application is:

[0007] In a first aspect, the present application provides a battery leakage detection circuit, comprising: a liquid level sensor and a resistance detection module; the liquid level sensor comprises a first probe and a second probe spaced apart at the bottom of the battery; the first probe and the second probe are used to detect whether the battery is leaking; the first end of the first probe and the first end of the second probe are respectively connected to the resistance detection module; the resistance detection module is used to determine whether there is leakage in the battery when a first resistance value of an equivalent resistance between the first probe and the second probe is detected, and to determine whether there is leakage in the battery when an open circuit state is detected between the first probe and the second probe.

[0008] In a possible implementation of the first aspect, the resistance detection module is further configured to determine leakage depth information in the battery based on a relationship between the detected first resistance value and a preset resistance threshold.

[0009] In a possible implementation of the first aspect, the battery leakage detection circuit further includes a power supply, a voltage-dividing resistor, and a capacitor; the first end of the first probe and the first end of the second probe are respectively connected to the power supply via wires, the first end of the voltage-dividing resistor is connected to the power supply, the second end of the voltage-dividing resistor is connected to the first end of the first probe and the first end of the capacitor, and the second end of the capacitor is connected to the first end of the second probe and to ground.

[0010] In a second aspect, the present application provides a battery leakage monitoring system, which includes: the battery leakage monitoring system includes a battery management system, a drain valve and the battery leakage detection circuit described in the first aspect; the battery leakage detection circuit is communicatively connected to the battery management system, and the battery management system is communicatively connected to the drain valve; the battery leakage detection circuit is used to report the first resistance value detected between the first probe and the second probe to the battery management system through a resistance detection module when there is leakage in the battery; the battery management system is used to send an opening instruction to the drain valve when the first resistance value is less than a preset first resistance threshold; the drain valve is used to open the valve body based on the opening instruction to discharge the leakage in the battery.

[0011] Through the above method, the first probe and the second probe based on the battery leakage detection circuit can promptly detect whether the battery is leaking. In the event of leakage, the drain valve is promptly controlled to discharge the liquid based on the change in the resistance value of the first probe and the second probe, thereby alleviating the risk of battery leakage and reducing the possibility of danger caused by leakage. It has strong ease of use and practicality.

[0012] In a possible implementation of the second aspect, the first probe, the second probe, and the drain valve of the battery leakage detection circuit are disposed at top corners of the inner bottom of the battery.

[0013] In the above manner, the battery may be at the lowest point at different positions on the bottom when in different states, such as when tilted. In order to cover leakage situations under as many working conditions as possible, a first probe and a second probe can be set at each top corner of the bottom (the common lowest point of the battery at multiple angles). The probes can detect the position where the fluid accumulation may be deepest, so as to promptly detect battery leakage and control the drain valve to discharge the liquid in time. Based on a minimum of leakage sensors and drain valves, leakage monitoring and drainage can be achieved to alleviate the risk of battery leakage.

[0014] In a possible implementation of the second aspect, the battery leakage monitoring system also includes an insulation detection device; the insulation detection device is communicatively connected to the battery management system; the insulation detection device is used to detect a second resistance value of the insulation resistance in the battery and report it to the battery management system; the battery management system is also used to control the power of the battery from the first power to the second power when the first resistance value is less than the first resistance threshold and the second resistance value is less than the second resistance threshold.

[0015] In the above manner, by combining the insulation detection device with the battery leakage detection circuit, the operating state of the battery can be determined more promptly and accurately based on the detected leakage state and the insulation resistance state of the battery, and the corresponding control action can be executed in a timely manner according to the current operating state; when there is a small amount of leakage in the battery and the insulation resistance value is reduced, an early warning and processing can be carried out, thereby reducing the possibility of danger to the battery due to leakage.

[0016] In a possible implementation of the second aspect, the battery leakage monitoring system also includes a relay; the relay is communicatively connected to the battery management system; the battery management system is further used to control the relay to disconnect when the first resistance value is less than a preset third resistance threshold and the second resistance value is less than or equal to a preset fourth resistance threshold; wherein the third resistance threshold is less than the first resistance threshold, and the fourth resistance threshold is less than the second resistance threshold.

[0017] In the above manner, by combining the insulation detection device with the battery leakage detection circuit, based on the detected leakage status and the insulation resistance status of the battery, the operating status of the battery can be determined more promptly and accurately, and the corresponding control action can be executed in time according to the current operating status. In this way, early warning and processing can be carried out before the leakage increases and the insulation resistance fails, thereby reducing the possibility of danger caused by battery leakage.

[0018] In a possible implementation of the second aspect, the battery leakage monitoring system also includes a fuse; the fuse is communicatively connected to the battery management system; the battery management system is further used to control the fuse to disconnect when the first resistance value is less than or equal to a fifth resistance threshold; wherein the fifth resistance threshold is less than the third resistance threshold.

[0019] Through the above method, based on the different resistance values ​​corresponding to different leakage levels in the battery, it is possible to judge whether the battery is leaking and the extent of the leakage, and to provide an early warning and handle the problem before the insulation resistance fails. At the same time, when the insulation resistance fails, the battery status can be detected by the battery leakage detection circuit, thereby improving the safety of the battery.

[0020] In a third aspect, the present application provides a battery leakage monitoring method, which is applied to the battery leakage monitoring system as described in the second aspect; the method comprises:

[0021] Obtaining a first resistance value between a first probe and a second probe in a battery leakage detection circuit; and controlling the drain valve to open to drain the leaked liquid in the battery when the first resistance value is less than a preset first resistance threshold.

[0022] In a possible implementation of the third aspect, the method further includes: obtaining a second resistance value of the insulation resistor; when the first resistance value is less than a preset first resistance threshold and the second resistance value is less than or equal to the second resistance threshold, controlling the drain valve to open, and controlling the power of the battery to drop from the first power to the second power.

[0023] In a possible implementation of the third aspect, the method further includes:

[0024] When the first resistance value is less than a preset third resistance threshold and the second resistance value is less than or equal to a preset fourth resistance threshold, the relay is controlled to disconnect; when the first resistance value is less than or equal to a fifth resistance threshold, the fuse is controlled to disconnect; wherein, the battery leakage monitoring system includes the relay and the fuse; the third resistance threshold is less than the first resistance threshold, the fourth resistance threshold is less than the second resistance threshold, and the fifth resistance threshold is less than the third resistance threshold.

[0025] In a fourth aspect, the present application provides a battery leakage monitoring system, which includes: one or more processors, and a memory; the memory is coupled to the one or more processors, and the memory is used to store computer program code, the computer program code includes computer instructions, and the one or more processors call the computer instructions to enable the battery leakage monitoring system to execute the method described in the third aspect.

[0026] In a fifth aspect, the present application provides a power battery system, which includes the battery leakage monitoring system and a battery as described in the second aspect, wherein the battery leakage monitoring system is used to monitor whether the battery has leakage.

[0027] In a sixth aspect, the present application provides an electric vehicle comprising the power battery system described in the fourth aspect.

[0028] In a seventh aspect, the present application provides a computer-readable storage medium having a computer program stored thereon, which implements the method described in any one of the third aspects when the computer program is executed by a processor.

[0029] In an eighth aspect, the present application provides a computer program product, which, when executed on an electrical device, enables the electrical device to execute any one of the methods described in the third aspect.

[0030] It can be understood that the beneficial effects of the above-mentioned first aspect and the third aspect to the eighth aspect can be found in the relevant description of the above-mentioned second aspect, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0032] FIG1 is a schematic diagram of an application scenario of battery leakage detection provided by an embodiment of the present application;

[0033] FIG2 is a schematic diagram of the structure of a battery leakage detection circuit provided in an embodiment of the present application;

[0034] FIG3 is a schematic structural diagram of a battery leakage monitoring system provided in an embodiment of the present application;

[0035] FIG4 is a schematic diagram of the layout of the probe and the drain valve provided in an embodiment of the present application;

[0036] FIG5 is a schematic diagram of an implementation flow of a battery leakage monitoring method provided in an embodiment of the present application;

[0037] FIG6 is a schematic diagram of a flow chart of a battery leakage monitoring method according to another embodiment of the present application;

[0038] FIG7 is a schematic diagram of the structure of a battery leakage detection system provided in an embodiment of the present application;

[0039] FIG8 is a schematic structural diagram of a power battery system provided in an embodiment of the present application. Modes for Carrying Out the Invention

[0040] The following embodiments of the technical solution of the present application will be described in detail with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application and are therefore only examples and are not intended to limit the scope of protection of the present application.

[0041] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned figure descriptions are intended to cover non-exclusive inclusions.

[0042] In the description of the embodiments of this application, the technical terms "first" and "second" are used only to distinguish different objects and should not be understood to indicate or imply relative importance or implicitly specify the quantity, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, the meaning of "plurality" is more than two, unless otherwise clearly and specifically defined.

[0043] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0044] In the description of the embodiments of this application, the term "and / or" is simply a description of the association relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent the following three situations: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this document generally indicates that the associated objects are in an "or" relationship.

[0045] As the sole power source for electric vehicles, the performance and service life of power batteries directly impact the performance and lifespan of the entire vehicle. Among various environmental factors, temperature has the greatest impact on the charge and discharge performance of power batteries. Therefore, power batteries are typically equipped with a battery thermal management system. Currently, there are three types of battery thermal management systems: air-cooled, direct-cooled, and liquid-cooled. Liquid-cooled battery thermal management systems can control the battery temperature between 25°C and 35°C, effectively extending the lifespan and performance of power batteries, and are therefore the most widely used.

[0046] However, liquid-cooled battery thermal management systems pose a safety hazard due to liquid leakage. Current battery systems rely on insulation testing to determine insulation failure, a method that exhibits a certain delay and single-source nature. For example, if the insulation resistance drops below the alarm value, the battery may have experienced a short circuit or a potential hazard. Furthermore, if the insulation detection circuit fails, the battery system loses its ability to detect faults.

[0047] To address the above-mentioned issues, the embodiments of the present application provide a battery leakage detection circuit, a battery leakage monitoring system, and a battery leakage monitoring method, which can timely detect whether the battery is leaking and perform corresponding control actions to alleviate the safety hazards caused by battery leakage.

[0048] The following describes the battery leakage detection process and the corresponding control process through specific embodiments.

[0049] As shown in Figure 1, an application scenario diagram of battery leakage detection provided in an embodiment of the present application shows that when the battery is stationary or running, a battery leakage detection circuit is added on the basis of the insulation detection of the battery to timely monitor the leakage status of the battery, making high-voltage monitoring of the entire vehicle with the battery installed safer and more reliable.

[0050] As shown in FIG1 , the battery leakage detection circuit may include a liquid level sensor and a resistance detection module. The resistance detection module may be integrated into a battery management system (BMS) or interact with the BMS as an independent module.

[0051] It is understood that a cavity is provided at the bottom of the battery; as shown in FIG1 , the liquid level sensor of the battery leakage detection circuit may include a first probe and a second probe; the first probe and the second probe may be spaced apart in the cavity at the bottom of the battery to detect whether the battery is leaking. The first probe and the second probe may be spaced apart in the cavity, side by side, or may be spaced apart, to ensure that the second ends of the two probes are close to the bottom of the battery and form a certain angle with the horizontal plane, such as 90°. The bottom of the battery is the lowest point close to the ground when the battery is in a horizontal or tilted state, whether at rest or in operation.

[0052] Correspondingly, the first end of the first probe and the first end of the second probe are respectively connected to the resistance detection module; when the resistance detection module detects a first resistance value of the equivalent resistance between the first probe and the second probe, it determines that there is leakage in the battery; when it detects that there is an open circuit between the first probe and the second probe, it determines that there is no leakage in the battery.

[0053] Among them, the battery leakage detection circuit also includes a power supply, a voltage divider resistor and a capacitor; the first ends of the first probe and the second probe are respectively connected to the power supply end through wires, and the second ends of both are close to the bottom surface of the battery cavity; when there is no leakage in the battery, the second ends of the first probe and the second probe are in an open circuit state, that is, the resistance value of the equivalent resistance between the first probe and the second probe is close to infinity; when there is leakage at the bottom of the battery, the second ends of the first probe and the second probe are in contact with the leakage, and the first probe and the second probe are in a conductive state, and the resistance detection module can detect the voltage between the first probe and the second probe and calculate the resistance value of the equivalent resistance.

[0054] Exemplarily, the first probe and the second probe can be flat probes. When the two probes are set, the flat planes can be arranged at the lowest point in the battery cavity in a relative and side-by-side manner, or movable connection points can be set at the distal ends of the two probes, so that the probes are always perpendicular to the ground due to gravity at different tilt angles of the battery, thereby making the liquid depth measurement based on the probe more accurate.

[0055] Accordingly, the embodiment of the present application can calculate the resistance value of the equivalent resistance formed by the probe and the contacted liquid based on the mutual mapping area of ​​the two opposite flat surfaces of the two probes, the spacing between the two probes, and the liquid depth, liquid conductivity, and liquid shape.

[0056] Among them, when there are multiple lowest point positions in the battery cavity under different states, a pair of probes can be set at each lowest point position, and the probes at different positions are set with corresponding numbers. When the probe contacts the liquid to generate a voltage signal, the current lowest point position can be determined based on the probe circuit that generates the signal. Based on the determined position, the shape of the liquid when leakage occurs can be further determined, such as a cube, a triangular pyramid or a cone.

[0057] For example, when calculating the effective conductive volume of the liquid, an integral operation can be performed based on the liquid shape, the distance between the two probes, and the relative mapped effective area. The liquid conductivity can generally be defaulted to the conductivity of a known liquid type, such as the conductivity of a coolant.

[0058] In this way, the resistance value of the equivalent resistance formed by the leakage between the first probe and the second probe can be determined based on the current value in the battery leakage detection circuit and the voltage divider between the first probe and the second probe. Then, based on the above principle, the state of the leakage can be determined, for example, the depth information of the leakage can be solved.

[0059] It can be understood that the more leakage in the battery, the greater the contact area between the leakage and the probe, and the smaller the resistance value of the equivalent resistance formed between the first probe and the second probe; thus, the change in the leakage depth can be further determined based on the change in the resistance value between the first probe and the second probe.

[0060] Exemplarily, when the resistance detection module is integrated into the BMS, the BMS can provide power for the battery leakage detection circuit and obtain the voltage change between the first probe and the second probe. Then, based on the current in the battery leakage detection circuit, the resistance value of the first probe and the second probe when they are in contact with the leakage and in the conductive state is calculated, and the leakage status is judged according to the change in the resistance value.

[0061] As shown in Figure 2, an equivalent structural diagram of a battery leakage detection circuit provided in an embodiment of the present application is shown. Figure 2 (a) is an equivalent circuit diagram of the battery leakage detection circuit when there is no leakage in the battery, and Figure 2 (b) is an equivalent circuit diagram when there is leakage in the battery.

[0062] As shown in Figure 2, the battery leakage detection circuit includes a liquid level sensor and a power supply Vin; wherein the liquid level sensor includes a first probe and a second probe arranged side by side and spaced apart; the first probe and the second probe are used to detect the leakage status of the battery; the first end of the first probe and the first end of the second probe are respectively connected to the power supply via wires.

[0063] Exemplarily, as shown in FIG2 , the battery leakage detection circuit further includes a voltage divider resistor R1 and a capacitor C1; a first end of the voltage divider resistor R1 is connected to a power supply, a second end of the voltage divider resistor R1 is connected to a first end of a first probe and a first end of the capacitor C1, and a second end of the capacitor C1 is connected to a first end of a second probe and is grounded.

[0064] As shown in Figure 2 (a), when there is no leakage in the cavity at the bottom of the battery, the circuit between the first and second probes is open, the equivalent resistance approaches infinity, and the corresponding voltage divider is also at its maximum. As shown in Figure 2 (b), when there is leakage in the cavity at the bottom of the battery and it contacts the two probes, an equivalent resistance R2 is formed between the first and second probes. The higher the level of the leakage, the smaller the value of equivalent resistance R2. Therefore, based on the voltage divider between R1 and equivalent resistance R2 in the circuit and the current, the magnitude of R2 can be calculated, and the leakage situation can be further determined based on R2, such as whether there is leakage in the battery or the leakage depth if leakage exists.

[0065] In the above manner, the battery leakage detection circuit can detect abnormalities in a timely manner and issue an early warning when there is a small amount of leakage in the battery but does not cause the insulation resistance of the insulation detection to decrease or fail, thereby ensuring the safety of the battery.

[0066] Based on the aforementioned battery leakage detection circuit, an embodiment of the present application further provides a battery leakage monitoring system. As shown in Figure 3, the battery leakage monitoring system provided in an embodiment of the present application can promptly execute corresponding control actions when the battery leakage detection circuit detects battery leakage, thereby reducing the risk of battery leakage.

[0067] As shown in FIG. 3 ( a ), the battery leakage monitoring system may include a battery management system BMS, a drain valve, and a battery leakage detection circuit as shown in FIG. 2 .

[0068] The battery leakage detection circuit is in communication with the battery management system, which is in communication with the drain valve. When the battery leakage detection circuit detects leakage in the battery based on a first probe and a second probe, the resistance detection module reports a first resistance value (i.e., equivalent resistance R2) formed between the first and second probes to the battery management system. Alternatively, the battery management system detects a change in voltage between the first and second probes and calculates the first resistance value based on the current in the battery leakage detection circuit. If the first resistance value is less than a preset first resistance threshold, an opening instruction is sent to the drain valve, which then opens based on the control valve body to drain the leaked liquid from the battery.

[0069] For example, the resistance threshold can be calibrated based on the conductivity of different liquids and the horizontal spacing between the two probes. For example, based on the conductivity of different types of liquids in a battery and the horizontal spacing between the two probes, the resistance threshold corresponding to different types of liquids can be calibrated. That is, different types of liquids can correspond to different resistance thresholds.

[0070] In addition, for each type of leakage, the resistance thresholds corresponding to multiple stages can be calibrated based on the conductivity, the horizontal spacing between the two probes, and the liquid depth. That is, when the actual spacing between the two probes is determined, the same liquid can correspond to different resistance thresholds at different depths.

[0071] In some embodiments, in order to be suitable for more application scenarios and working conditions of the battery, a first probe, a second probe, and a drain valve can be set based on the position of the lowest point that the battery may produce during application; as shown in Figure 4, the first probe, the second probe, and the drain valve of the battery leakage detection circuit are set at the top corner position of the bottom of the battery.

[0072] For example, taking the installation method of the power battery of an electric vehicle as an example, when the electric vehicle is parked on the ground or driving, the battery may tilt at any angle, and probes and drain valves for detection are arranged at the common lowest point of multiple angles. That is, when a position is the common lowest point of multiple tilt angles, a pair of leakage detection probes and a drain valve are arranged at the common lowest point.

[0073] As shown in Figure 4, taking a battery with a rectangular bottom as an example, when the battery box is tilted, the leaked liquid mainly accumulates at the lowest corner position; when the electric vehicle is tilted in different directions, the lowest points of the four corners at the bottom of the battery correspond to the deepest liquid accumulation positions, so a pair of detection probes and a drain valve can be arranged at the four corners at the bottom of the battery respectively.

[0074] It should be noted that batteries may have different numbers or positions of lowest points due to different structures. The above-mentioned use of the top corner of the bottom surface of the battery as the position of the lowest point is only an example. The specific position can be determined according to the status of the battery setting. Corresponding detection probes and drain valves are set for the common lowest points in multiple tilt directions, so as to cover more leakage conditions with the lowest parts cost, and ensure that the leakage detection function will not fail due to different vehicle tilt angles.

[0075] For example, when a leak is detected, the drain valve can be controlled to open and drain the leak. The drain valve can be set to open passively or actively. For example, when a leak is detected, the BMS sends an opening command to the drain valve, which passively opens the valve body based on the opening command to drain the leak. Alternatively, when a leak is detected, the drain valve can be set to expand when it encounters liquid, and the expansion force actively opens the valve body to drain the liquid.

[0076] For example, the relative position of the detection probe and the drain valve can be set based on an actual application scenario, or based on the structural characteristics of the determined lowest point position.

[0077] As shown in Figure 3 (b), the battery leakage monitoring system also includes an insulation detection device, which is communicatively connected to the battery management system; the insulation detection device detects the second resistance value of the insulation resistance in the battery and reports it to the battery management system; the battery management system compares the first resistance value with the first resistance threshold, and the second resistance value with the second resistance threshold, and when the first resistance value is less than the first resistance threshold, and / or the second resistance value is less than or equal to the second resistance threshold, controls the power of the battery to drop from the first power to the second power.

[0078] Among them, the first power can be the current operating power of the battery, and the second power is a power value less than the first power determined based on the detected leakage status and the current operating status of the battery. It can be set based on the current usage or scenario of the battery. For example, different reductions can be set for different usage scenarios to obtain the second power.

[0079] For example, as shown in Figure 3 (b), when leakage is detected in the battery, the BMS can control the drain valve to open while also controlling the battery power module to reduce the operating power of the battery, thereby promptly reducing damage to the battery due to leakage.

[0080] As shown in Figure 3 (b), the battery leakage monitoring system also includes a relay; the relay is communicatively connected to the battery management system; when the first resistance value is less than a preset third resistance threshold, and / or the second resistance value is less than or equal to a preset fourth resistance threshold, the relay is controlled to disconnect; wherein the third resistance threshold is less than the first resistance threshold, and the fourth resistance threshold is less than or equal to the second resistance threshold.

[0081] As shown in Figure 3 (b), the battery leakage monitoring system also includes a fuse; the fuse is communicatively connected to the battery management system; when the first resistance value is less than or equal to the fifth resistance threshold, the battery management system controls the fuse to disconnect; wherein the fifth resistance threshold is less than the third resistance threshold.

[0082] Exemplarily, different threshold intervals can be set for the resistance threshold, and the set resistance thresholds can be the boundary values ​​of each threshold interval. For example, the upper limit of the first threshold interval can be the first resistance threshold, and the lower limit can be the third resistance threshold; the upper limit of the second threshold interval can be the third resistance threshold, and the lower limit of the second threshold interval can be the fifth resistance threshold.

[0083] Accordingly, when the battery leakage detection circuit begins to detect leakage in the battery, corresponding control actions can be performed in sequence based on the changes in the first resistance value of the equivalent resistor R2 obtained, such as the process in which the first resistance value gradually decreases as the leakage increases, and the comparison results between the first resistance value and each resistance threshold.

[0084] For example, when there is no leakage in the battery (R2 ≥ 10MΩ), the battery operates normally without any treatment; when the liquid begins to contact the probe, it detects 3MΩ ≤ R2 < 4MΩ (first resistance threshold), at which time the insulation detection device has not found any abnormality, and the BMS can open the drain valve in advance and reduce the battery operating power; when the liquid submerges half of the probe, it detects 1MΩ ≤ R2 < 3MΩ (third resistance threshold), at which time the insulation detection resistance drops but does not trigger an alarm. The BMS takes into account the information of insulation detection and leakage detection, reduces the battery operating power to 0kw and cuts off the relay; when the liquid completely submerges the probe, it detects R2 < 1MΩ (fifth resistance threshold), at which time the insulation has failed and the fuse is cut off.

[0085] For example, when battery leakage is detected and the insulation detection device detects that the second resistance value of the insulation resistance is less than 500Ω / V (second resistance threshold), the BMS opens the drain valve and reduces the battery power; when the first resistance value is less than the third resistance threshold and the second resistance value is less than or equal to 100Ω / V (fourth resistance threshold), the BMS controls the battery power to be reduced to 0 and cuts off the relay.

[0086] In one possible implementation, when the battery leakage detection circuit detects that the battery is leaking and the insulation detection device does not detect a change in insulation resistance, it can also control the drain valve to discharge liquid and control the battery power module to reduce the operating power of the battery, thereby timely reducing the damage to the battery caused by leakage and reducing the possibility of battery danger.

[0087] Exemplarily, when the battery leakage detection circuit detects that the battery is leaking, the corresponding control action can be performed based on the relationship between the resistance value of the equivalent resistance between the first probe and the second probe and the size of each resistance threshold, such as opening the drain valve, reducing the battery power, disconnecting the relay or disconnecting the fuse; or when the battery leakage is detected, the drain valve is opened in combination with the change in the resistance value of the insulation resistance, and the depth of the leakage is judged based on the resistance value of the equivalent resistance, and compared with the preset liquid level depth threshold, and in combination with the further change in the resistance value of the insulation resistance, the battery power is reduced to 0 and the relay is disconnected; and when the leakage depth reaches the preset liquid level depth threshold, the fuse is controlled to disconnect.

[0088] It should be noted that the above setting of the resistance threshold or the setting of the interval range corresponding to the resistance threshold is only for illustrative purposes. The specific value of the resistance threshold can be set based on the structure of the battery and the requirements of the actual application scenario; the change in the equivalent resistance between the first probe and the second probe relative to different resistance thresholds can be used as a basis for judging the depth of battery leakage.

[0089] Based on the above-mentioned battery leakage monitoring system, an embodiment of the present application provides a battery leakage monitoring method, which is applied to the above-mentioned battery leakage monitoring system. The implementation principle of this method is the same as that of the above-mentioned embodiment and is not further described here. As shown in FIG5 , the method may include the following steps:

[0090] S501 : Obtain a first resistance value between a first probe and a second probe in a battery leakage detection circuit.

[0091] For example, the BMS may determine the first resistance value of the equivalent resistor R2 based on the divided voltage and the current between the first probe and the second probe.

[0092] S502 : When the first resistance value is less than a preset first resistance threshold, control the drain valve to open to drain the leaked liquid in the battery.

[0093] In some embodiments, the method further includes: obtaining a second resistance value of the insulation resistance; when the first resistance value is less than a preset first resistance threshold and the second resistance value is less than or equal to the second resistance threshold, controlling the drain valve to open, and controlling the power of the battery to drop from the first power to the second power.

[0094] In some embodiments, the method further includes: controlling the relay to disconnect when the first resistance value is less than a preset third resistance threshold and the second resistance value is less than or equal to a preset fourth resistance threshold; controlling the fuse to disconnect when the first resistance value is less than or equal to a fifth resistance threshold; wherein the battery leakage monitoring system includes a relay and a fuse; the third resistance threshold is less than the first resistance threshold, the fourth resistance threshold is less than or equal to the second resistance threshold, and the fifth resistance threshold is less than the third resistance threshold.

[0095] As shown in Figure 6, a schematic diagram of the implementation flow of a battery leakage monitoring method provided by another embodiment of the present application is provided; after the battery leakage monitoring system is initialized, leakage detection and insulation detection can be started simultaneously. When leakage is determined to be present through leakage detection and insulation resistance is less than or equal to 500Ω / V through insulation detection, the drain valve is opened and the battery power is reduced; the resistance value of the equivalent resistance between the first probe and the second probe gradually decreases and does not reach the preset resistance threshold, or the liquid level rises but does not reach the preset depth threshold, the second resistance value of the insulation resistance is less than or equal to 100Ω / V, the battery power is controlled to be reduced to 0 and the relay is cut off; the resistance value of the equivalent resistance between the first probe and the second probe reaches the preset resistance threshold (for example, the first resistance value is less than the third resistance threshold), or the liquid level reaches the preset depth threshold (for example, the liquid level covers and submerges the probe), at this time the insulation resistance fails and the fuse is cut off.

[0096] Through the embodiments of the present application, the first probe and the second probe based on the battery leakage detection circuit can promptly detect whether the battery is leaking, and in the event of leakage, the drain valve is promptly controlled to discharge the liquid based on the change in the resistance value of the first probe and the second probe, thereby alleviating the risk of battery leakage and reducing the possibility of danger caused by battery leakage. Early warning and processing can be carried out before the insulation resistance fails. At the same time, when the insulation resistance fails, the battery leakage detection circuit can also be used to detect the battery status; it has strong ease of use and practicality.

[0097] It should be understood that the size of the serial numbers of the steps in the above embodiments does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0098] FIG7 shows a schematic diagram of the hardware structure of the battery leakage monitoring system 7 .

[0099] As shown in FIG7 , the battery leakage monitoring system 7 of this embodiment includes: at least one processor 70 (only one is shown in FIG7 ) and a memory 71 , wherein the memory 71 stores a computer program 72 executable on the processor 70 . When the processor 70 executes the computer program 72, it implements the steps of the above-described method embodiment, such as S501 to S502 shown in FIG5 . Alternatively, when the processor 70 executes the computer program 72, it implements the functions of the modules of the above-described device embodiment.

[0100] It should be understood that the structure illustrated in the embodiments of this application does not constitute a specific limitation on the battery leakage monitoring system 7. In other embodiments of this application, the battery leakage monitoring system 7 may include more or fewer components than illustrated, or may combine or separate certain components, or have different component arrangements. The illustrated components may be implemented in hardware, software, or a combination of software and hardware.

[0101] The battery leakage monitoring system 7 may be a high-voltage safety system for the battery; the battery leakage monitoring system 7 may include, but is not limited to, a processor 70 and a memory 71. Those skilled in the art will appreciate that FIG7 is merely an example of the battery leakage monitoring system 7 and does not limit the battery leakage monitoring system 7 . The battery leakage monitoring system 7 may include more or fewer components than shown, or may combine certain components or different components. For example, the server may also include an input and transmission device, a network access device, a bus, etc.

[0102] The processor 70 may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or any conventional processor.

[0103] The processor 70 may also include a memory for storing instructions and data. In some embodiments, the memory in the processor 70 is a cache memory. This memory can store instructions or data that the processor 70 has just used or is reusing. If the processor 70 needs to use the instruction or data again, it can directly call it from the memory. This avoids repeated accesses, reduces the processor 70's waiting time, and thus improves system efficiency.

[0104] In some embodiments, the memory 71 may be an internal storage unit of the battery leakage monitoring system 7, such as a hard drive or memory of the battery leakage monitoring system 7. The memory 71 may also be an external storage device of the battery leakage monitoring system 7, such as a plug-in hard drive, a smart media card (SMC), a secure digital (SD) card, a flash card, etc. equipped on the battery leakage monitoring system 7. Furthermore, the memory 71 may include both an internal storage unit of the battery leakage monitoring system 7 and an external storage device. The memory 71 is used to store an operating system, application programs, a boot loader, data, and other programs, such as program code of a computer program. The memory 71 may also be used to temporarily store data that has been sent or is about to be sent.

[0105] In addition, the functional units in the various embodiments of the present application may be integrated into a single processing unit, or each unit may exist physically separately, or two or more units may be integrated into a single unit. The aforementioned integrated units may be implemented in the form of hardware or software functional units.

[0106] It should be noted that the structure of the above-mentioned electronic device is only illustrative, and based on different application scenarios, it may also include other physical structures, and the physical structure of the electronic device is not limited here.

[0107] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant description of other embodiments.

[0108] As shown in FIG8 , an embodiment of the present application further provides a power battery system, comprising the above-mentioned battery leakage monitoring system 7 and a battery 81 . The battery leakage monitoring system is used to monitor whether the battery has leakage.

[0109] An embodiment of the present application also provides an electric vehicle, comprising the above-mentioned power battery system.

[0110] An embodiment of the present application further provides a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, the above-mentioned various method embodiments are implemented.

[0111] An embodiment of the present application provides a computer program product. When the computer program product runs on a server, the server implements the above-mentioned various method embodiments when executing the computer program product.

[0112] If the integrated module / unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the present application implements all or part of the process in the above-mentioned embodiment method, and can also be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium, and the computer program can implement the steps of the above-mentioned various method embodiments when executed by the processor. Among them, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form, etc. Computer-readable media may include: any entity or device that can carry computer program code, recording medium, U disk, mobile hard disk, magnetic disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electric carrier signal, telecommunication signal and software distribution medium, etc.

[0113] The battery leakage monitoring system, computer storage medium, and computer program product provided in the above-mentioned embodiments of the present application are all used to execute the method provided above. Therefore, the beneficial effects that can be achieved can refer to the corresponding beneficial effects of the method provided above, and will not be repeated here.

[0114] It should be understood that the above is only to help those skilled in the art better understand the embodiments of the present application, and is not intended to limit the scope of the embodiments of the present application. Based on the above examples given, those skilled in the art can obviously make various equivalent modifications or changes. For example, certain steps in each embodiment of the above detection method may be unnecessary, or certain new steps may be added. Or a combination of any two or any multiple embodiments described above. Such modifications, changes, or combined solutions also fall within the scope of the embodiments of the present application.

[0115] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0116] It should be understood that the above is only to help those skilled in the art better understand the embodiments of the present application, and is not intended to limit the scope of the embodiments of the present application. Based on the above examples given, those skilled in the art can obviously make various equivalent modifications or changes. For example, certain steps in each embodiment of the above detection method may be unnecessary, or certain new steps may be added. Or a combination of any two or any multiple embodiments described above. Such modifications, changes, or combined solutions also fall within the scope of the embodiments of the present application.

[0117] It should also be understood that the division of the modes, situations, categories and embodiments in the embodiments of the present application is only for the convenience of description and should not constitute a special limitation. The features of various modes, categories, situations and embodiments can be combined without contradiction.

[0118] It should also be understood that in the various embodiments of the present application, unless otherwise specified or there is a logical conflict, the terms and / or descriptions between different embodiments are consistent and can be referenced to each other, and the technical features in different embodiments can be combined to form new embodiments according to their internal logical relationships.

[0119] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0120] In the embodiments provided in this application, it should be understood that the disclosed devices / network equipment and methods can be implemented in other ways. For example, the device / network equipment embodiments described above are merely illustrative. For example, the division of the modules or units is merely a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0121] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0122] The above-described embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present application, and should all be included in the scope of protection of the present application.

[0123] Finally, it should be noted that the above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any changes or substitutions within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. A battery leakage detection circuit, characterized in that: The battery leakage detection circuit includes: a liquid level sensor and a resistance detection module; The liquid level sensor includes a first probe and a second probe spaced apart at the bottom of the battery; the first probe and the second probe are used to detect whether the battery is leaking; The first end of the first probe and the first end of the second probe are respectively connected to the resistance detection module; the resistance detection module is used to determine that there is leakage in the battery when a first resistance value of the equivalent resistance between the first probe and the second probe is detected, and to determine that there is no leakage in the battery when an open circuit state is detected between the first probe and the second probe.

2. The battery leakage detection circuit according to claim 1, characterized in that: The resistance detection module is further configured to determine leakage depth information in the battery based on a relationship between the detected first resistance value and a preset resistance threshold.

3. The battery leakage detection circuit according to claim 1 or 2, characterized in that: The battery leakage detection circuit also includes a power supply, a voltage divider resistor, and a capacitor; the first end of the first probe and the first end of the second probe are respectively connected to the power supply via wires, the first end of the voltage divider resistor is connected to the power supply, the second end of the voltage divider resistor is connected to the first end of the first probe and the first end of the capacitor, and the second end of the capacitor is connected to the first end of the second probe and to ground.

4. A battery leakage monitoring system, characterized in that: The battery leakage monitoring system comprises a battery management system, a drain valve, and the battery leakage detection circuit according to any one of claims 1 to 3; the battery leakage detection circuit is communicatively connected to the battery management system, and the battery management system is communicatively connected to the drain valve; The battery leakage detection circuit is configured to report the first resistance value detected between the first probe and the second probe to the battery management system through the resistance detection module when leakage occurs in the battery; The battery management system is configured to send an opening instruction to the drain valve when the first resistance value is less than a preset first resistance threshold; The drain valve is used to open the valve body based on the opening instruction to discharge the leaked liquid in the battery.

5. The battery leakage monitoring system according to claim 4, characterized in that: The battery leakage monitoring system further includes an insulation detection device; the insulation detection device is communicatively connected to the battery management system; The insulation detection device is used to detect a second resistance value of the insulation resistance in the battery and report it to the battery management system; The battery management system is further configured to control the power of the battery to decrease from a first power to a second power when the first resistance value is less than the first resistance threshold and the second resistance value is less than a second resistance threshold.

6. The battery leakage monitoring system according to claim 5, characterized in that: The battery leakage monitoring system further includes a relay; the relay is communicatively connected to the battery management system; The battery management system is further configured to control the relay to disconnect when the first resistance value is less than a preset third resistance threshold and the second resistance value is less than or equal to a preset fourth resistance threshold; The third resistance threshold is smaller than the first resistance threshold, and the fourth resistance threshold is smaller than the second resistance threshold.

7. The battery leakage monitoring system according to claim 6, characterized in that: The battery leakage monitoring system further includes a fuse; the fuse is communicatively connected to the battery management system; The battery management system is further configured to control the fuse to disconnect when the first resistance value is less than or equal to a fifth resistance threshold; wherein the fifth resistance threshold is less than the third resistance threshold.

8. The battery leakage monitoring system according to any one of claims 4 to 7, characterized in that: The first probe, the second probe and the drain valve of the battery leakage detection circuit are arranged at the top corners of the bottom of the battery.

9. A battery leakage monitoring method, characterized in that: Applicable to a battery leakage monitoring system according to any one of claims 4 to 8; the method comprising: Obtaining a first resistance value between a first probe and a second probe in a battery leakage detection circuit; When the first resistance value is less than a preset first resistance threshold, the drain valve is controlled to open to drain the leaked liquid in the battery.

10. The method according to claim 9, characterized in that The method further comprises: Obtaining a second resistance value of the insulation resistance; When the first resistance value is less than a preset first resistance threshold and the second resistance value is less than or equal to a second resistance threshold, the drain valve is controlled to open, and the power of the battery is controlled to decrease from the first power to the second power.

11. The method according to claim 10, characterized in that The method further comprises: When the first resistance value is less than a preset third resistance threshold and the second resistance value is less than or equal to a preset fourth resistance threshold, controlling the relay to be disconnected; When the first resistance value is less than or equal to the fifth resistance threshold, the fuse is controlled to disconnect; wherein, the battery leakage monitoring system includes the relay and the fuse; the third resistance threshold is less than the first resistance threshold, the fourth resistance threshold is less than the second resistance threshold, and the fifth resistance threshold is less than the third resistance threshold.

12. A battery leakage monitoring system, characterized in that: The battery leakage monitoring system includes: one or more processors, and a memory; the memory is coupled to the one or more processors, the memory is used to store computer program code, the computer program code includes computer instructions, and the one or more processors call the computer instructions to enable the battery leakage monitoring system to perform the method according to any one of claims 9 to 11.

13. A power battery system, characterized in that: The invention comprises the battery leakage monitoring system as claimed in claim 4 and a battery, wherein the battery leakage monitoring system is used to monitor whether the battery has leakage.

14. An electric vehicle, characterized in that: Comprising the power battery system as claimed in claim 13.

15. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method according to any one of claims 9 to 11 is implemented.

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