Battery module detection system and method

Abstract

A battery module detection system and method. The battery module detection system comprises a control circuit and a detection circuit, wherein the detection circuit comprises a resistance unit. The control circuit is configured to: control to transmit a power supply voltage to the detection circuit and obtain a detection voltage fed back by the detection circuit, determine detection parameters inside a battery module on the basis of the power supply voltage, the detection voltage and the resistance value of the resistance unit, and on the basis of the detection parameters inside the battery module, determine whether an insulation abnormality is present inside the battery module or not.

Description

Battery module detection system and method

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on November 30, 2023, with application number 202311641695.7 and invention name “Battery Module Detection System and Method Thereof”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of power electronics technology, and in particular to a battery module detection system and method thereof. Background Art

[0003] A power battery pack is composed of one or more battery modules, each of which includes multiple battery cells. Typically, the outer shell of the power battery pack is insulated from the battery modules within the power battery pack, and the outer shell of each battery module is insulated from the multiple battery cells within the battery module.

[0004] However, affected by factors such as the environment and long-term operation, the battery cells inside the battery module are prone to insulation abnormalities such as leakage, arcing or micro-short circuits. When the insulation resistance between the battery module shell and the internal battery cells decreases, the insulation performance between the battery module shell and the internal battery cells deteriorates, which will bring safety hazards to the power battery pack and even related vehicles.

[0005] Summary of the Invention

[0006] In the first aspect, the present application provides a battery module detection system, which includes a control circuit and a detection circuit, the detection circuit is electrically connected to the outer shell of the battery module, the detection circuit includes a resistance unit, the control circuit is connected to the detection circuit, and the control circuit is used to: control the transmission of the power supply voltage to the detection circuit, and obtain the detection voltage fed back by the detection circuit; determine the detection parameters inside the battery module based on the power supply voltage, the detection voltage and the resistance value of the resistance unit, and determine whether there is an insulation abnormality inside the battery module based on the detection parameters inside the battery module.

[0007] In a possible implementation, the power supply voltage includes a first power supply voltage, the detection voltage includes a first detection voltage fed back by the detection circuit, and the detection parameter inside the battery module includes an insulation resistance of the battery module.

[0008] The above-mentioned control circuit is used to determine the insulation resistance of the above-mentioned battery module based on the above-mentioned first power supply voltage, the above-mentioned first detection voltage, and the resistance value of the above-mentioned resistance unit, and to determine whether there is an insulation abnormality between the multiple battery cells inside the above-mentioned battery module and the outer casing of the above-mentioned battery module based on the insulation resistance of the above-mentioned battery module and a preset resistance threshold.

[0009] In a possible implementation, the power supply voltage includes a first power supply voltage and a second power supply voltage, the detection voltage includes a first detection voltage and a second detection voltage, the first detection voltage being the detection voltage fed back by the detection circuit when the power supply voltage is the first power supply voltage; the second detection voltage being the detection voltage fed back by the detection circuit when the power supply voltage is the second power supply voltage; and the detection parameter inside the battery module includes the insulation resistance of the battery module;

[0010] The above-mentioned control circuit is used to determine the insulation resistance of the above-mentioned battery module based on the above-mentioned first power supply voltage, the above-mentioned second power supply voltage, the above-mentioned first detection voltage, the above-mentioned second detection voltage, and the resistance value of the above-mentioned resistance unit, and determine whether there is an insulation abnormality between the multiple battery cells inside the above-mentioned battery module and the outer casing of the above-mentioned battery module based on the insulation resistance of the above-mentioned battery module and a preset resistance threshold.

[0011] In a possible implementation, the detection parameter inside the battery module further includes the insulation voltage of the battery module;

[0012] The above-mentioned control circuit is used to determine the insulation voltage of the above-mentioned battery module based on the above-mentioned first power supply voltage, the above-mentioned second power supply voltage, the above-mentioned first detection voltage, the above-mentioned second detection voltage, and the resistance value of the above-mentioned resistance unit. When the above-mentioned insulation resistance is less than the above-mentioned preset resistance threshold, the battery cell with insulation abnormality is determined from the multiple battery cells inside the above-mentioned battery module based on the insulation voltage of the above-mentioned battery module.

[0013] In a possible implementation, the control circuit is configured to determine a cell inside the battery module corresponding to the acquired target voltage threshold range as a cell having an insulation abnormality when the insulation resistance is less than the preset resistance threshold.

[0014] In a possible embodiment, the resistor unit includes a first resistor, a second resistor, a third resistor, a fourth resistor, and a fifth resistor; one end of the first resistor is connected to the first port of the control circuit, the other end of the first resistor is respectively connected to one end of the second resistor, one end of the third resistor, and one end of the fourth resistor, the other end of the second resistor is connected to the second port of the control circuit, the other end of the third resistor, the other end of the fourth resistor, the other end of the third resistor, and one end of the fifth resistor are all grounded, and the other end of the fifth resistor is connected to the housing of the battery module;

[0015] The control circuit is used to transmit the power supply voltage through the first port and obtain the detection voltage through the second port.

[0016] In one possible implementation, the power supply voltage includes a first power supply voltage, and the detection voltage includes a first detection voltage fed back by the detection circuit; and the control circuit is configured to determine the insulation resistance inside the battery module based on the first power supply voltage, the first detection voltage, and the resistance value of the resistance unit, including:

[0017] The control circuit is used to calculate the insulation resistance of the battery module according to the following formula:

[0018] Among them, R is the resistance value of the above-mentioned insulation resistor, U1 is the above-mentioned first detection voltage, V1 is the above-mentioned first power supply voltage, R1 is the resistance value of the above-mentioned first resistor, R2 is the resistance value of the above-mentioned second resistor, R3 is the resistance value of the above-mentioned third resistor, R4 is the resistance value of the above-mentioned fourth resistor, and R5 is the resistance value of the above-mentioned fifth resistor.

[0019] In one possible implementation, the power supply voltage includes a first power supply voltage and a second power supply voltage, and the detection voltage includes a first detection voltage and a second detection voltage; and the control circuit is configured to determine the insulation resistance of the battery module based on the first power supply voltage, the second power supply voltage, the first detection voltage, the second detection voltage, and the resistance value of the resistance unit, including:

[0020] The control circuit is used to calculate the insulation resistance of the battery module according to the following formula:

[0021] Among them, R is the resistance value of the above-mentioned insulation resistor, U1 is the above-mentioned first detection voltage, U2 is the above-mentioned second detection voltage, V1 is the above-mentioned first power supply voltage, V2 is the above-mentioned second power supply voltage, R1 is the resistance value of the above-mentioned first resistor, R2 is the resistance value of the above-mentioned second resistor, R3 is the resistance value of the above-mentioned third resistor, R4 is the resistance value of the above-mentioned fourth resistor, and R5 is the resistance value of the above-mentioned fifth resistor.

[0022] In one possible implementation, the power supply voltage includes a first power supply voltage and a second power supply voltage, and the detection voltage includes a first detection voltage and a second detection voltage; and the control circuit is configured to calculate the insulation voltage of the battery module according to the following formula:

[0023] Among them, U x is the above-mentioned insulation voltage, U1 is the above-mentioned first detection voltage, U2 is the above-mentioned second detection voltage, V1 is the above-mentioned first power supply voltage, V2 is the above-mentioned second power supply voltage, R1 is the resistance value of the above-mentioned first resistor, R2 is the resistance value of the above-mentioned second resistor, R3 is the resistance value of the above-mentioned third resistor, R4 is the resistance value of the above-mentioned fourth resistor, and R5 is the resistance value of the above-mentioned fifth resistor.

[0024] In a possible implementation, the detection circuit further includes a first capacitor and a second capacitor; the first capacitor is connected in parallel to the third resistor, one end of the second capacitor is connected to the other end of the fourth resistor, and the other end of the second capacitor is grounded.

[0025] In a possible embodiment, the detection circuit further includes a first diode and a second diode; the positive electrode of the first diode is connected to the first port of the control circuit, and the negative electrode of the first diode is connected to one end of the second resistor; the negative electrode of the second diode is connected to the second port of the control circuit, and the positive electrode of the second diode is grounded.

[0026] In a second aspect, the present application further provides a battery module detection method, which is performed by a battery module detection system. The battery module detection system includes a control circuit and a detection circuit connected to the control circuit, the detection circuit being electrically connected to a housing of the battery module and including a resistor unit. The method includes:

[0027] The control circuit controls the transmission of the power supply voltage to the detection circuit and obtains the detection voltage fed back by the detection circuit;

[0028] The control circuit determines the detection parameters inside the battery module based on the power supply voltage, the detection voltage and the resistance value of the resistance unit, and determines whether there is an insulation abnormality inside the battery module based on the detection parameters inside the battery module.

[0029] In a possible implementation, the power supply voltage includes a first power supply voltage, the detection voltage includes a first detection voltage fed back by the detection circuit, and the detection parameter inside the battery module includes an insulation resistance of the battery module.

[0030] The method of determining the detection parameters inside the battery module based on the power supply voltage, the detection voltage, and the resistance value of the resistance unit, and determining whether an insulation abnormality exists inside the battery module based on the detection parameters inside the battery module, includes:

[0031] The insulation resistance of the battery module is determined based on the first power supply voltage, the first detection voltage, and the resistance value of the resistance unit, and whether there is an insulation abnormality between the multiple battery cells inside the battery module and the outer casing of the battery module is determined based on the insulation resistance of the battery module and a preset resistance threshold.

[0032] In a possible implementation, the power supply voltage includes a first power supply voltage and a second power supply voltage, the detection voltage includes a first detection voltage and a second detection voltage, the first detection voltage being the detection voltage fed back by the detection circuit when the power supply voltage is the first power supply voltage; the second detection voltage being the detection voltage fed back by the detection circuit when the power supply voltage is the second power supply voltage; and the detection parameter inside the battery module includes the insulation resistance of the battery module;

[0033] Determining detection parameters inside the battery module according to the power supply voltage, the detection voltage, and the resistance value of the resistance unit, and determining whether there is an insulation abnormality inside the battery module according to the detection parameters inside the battery module, including:

[0034] Based on the first power supply voltage, the second power supply voltage, the first detection voltage, the second detection voltage, and the resistance value of the resistance unit, the insulation resistance of the battery module is determined, and based on the insulation resistance of the battery module and a preset resistance threshold, it is determined whether there is an insulation abnormality between the multiple battery cells inside the battery module and the outer casing of the battery module.

[0035] In a possible implementation, the power supply voltage includes a first power supply voltage and a second power supply voltage, the detection voltage includes a first detection voltage and a second detection voltage, and the detection parameter inside the battery module further includes an insulation voltage of the battery module;

[0036] Determining detection parameters inside the battery module according to the power supply voltage, the detection voltage, and the resistance value of the resistance unit, and determining whether there is an insulation abnormality inside the battery module according to the detection parameters inside the battery module, including:

[0037] The above-mentioned control circuit is used to determine the insulation voltage of the above-mentioned battery module based on the above-mentioned first power supply voltage, the above-mentioned second power supply voltage, the above-mentioned first detection voltage, the above-mentioned second detection voltage, and the resistance value of the above-mentioned resistance unit. When the above-mentioned insulation resistance is less than the above-mentioned preset resistance threshold, the battery cell with insulation abnormality is determined from the multiple battery cells inside the above-mentioned battery module based on the insulation voltage of the above-mentioned battery module.

[0038] In a possible implementation, when the insulation resistance is less than the preset resistance threshold, determining a battery cell having an insulation abnormality from the plurality of battery cells within the battery module according to the insulation voltage of the battery module includes:

[0039] When the insulation resistance is less than the preset resistance threshold, the battery cell in the battery module corresponding to the acquired target voltage threshold interval is determined as a battery cell with insulation abnormality.

[0040] In a third aspect, the present application further provides a non-volatile computer-readable storage medium, which stores a computer program or computer instructions, and the aforementioned computer program or computer instructions are executed by a processor to implement any of the aforementioned methods in the above second aspect.

[0041] In a fourth aspect, the present application further provides a computer program product. When the computer program product is executed by a processor, any of the aforementioned methods in the second aspect will be executed.

[0042] In a fifth aspect, the present application further provides a battery information collector, which includes the battery module detection system of the first aspect.

[0043] In the sixth aspect, the present application also provides a power supply device, including a battery module, a battery management system and the battery module detection system of the first aspect or the battery information collector of the fifth aspect; the battery module detection system is used to detect insulation abnormalities inside the battery module, and generate detection results based on the insulation abnormalities inside the battery module, and send the detection results to the battery management system; the battery management system is used to output abnormal prompts or normal prompts based on the detection results.

[0044] In a possible implementation, the battery module includes at least two battery cells connected in series.

[0045] In the seventh aspect, the present application also provides an electric device, which includes the power supply device in the sixth aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. 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 labor.

[0047] FIG1 is a schematic structural diagram of a power battery pack provided in an embodiment of the present application;

[0048] FIG2 is another schematic structural diagram of a power battery pack provided in an embodiment of the present application;

[0049] FIG3 is a schematic structural diagram of a battery module detection system provided in an embodiment of the present application;

[0050] FIG4 is a schematic structural diagram of a detection circuit provided in an embodiment of the present application;

[0051] FIG5 is another schematic diagram of the structure of the detection circuit provided in an embodiment of the present application;

[0052] FIG6 is a flow chart of a battery module detection method provided by the present application;

[0053] FIG7 is a schematic structural diagram of a power supply device provided in an embodiment of the present application;

[0054] FIG8 is a schematic structural diagram of a battery information collector provided in an embodiment of the present application;

[0055] FIG9 is a schematic structural diagram of an electric device provided in an embodiment of the present application.

[0056] Explanation of the reference numerals: 300 - battery module detection system, 301 - control circuit, 302 - detection circuit, 320 - battery module, 330 - housing, 310 - power battery pack, (C1) - first capacitor, (C2) - second capacitor, (D1) - first diode, (D2) - second diode. DETAILED DESCRIPTION

[0057] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0058] The following are detailed descriptions of each.

[0059] The terms "first," "second," "third," and "fourth," etc., in the specification and claims of this application and the accompanying drawings are used to distinguish between different objects, rather than to describe a particular order. In addition, the terms "including," "having," and any variations thereof, are intended to cover non-exclusive inclusions. For example, a process, method, system, product, or apparatus comprising a series of steps or elements is not limited to the listed steps or elements, but may optionally include steps or elements not listed, or may optionally include other steps or elements inherent to the process, method, product, or apparatus.

[0060] 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.

[0061] It should be noted that the power battery pack is the power source of new energy vehicles, used to store and provide electrical energy to the new energy vehicle. Typically, the output voltage of a power battery pack exceeds 300 volts. Therefore, multiple battery cells can be connected in series or parallel to form a battery module, and multiple battery modules can be connected in series or parallel to form a power battery pack to increase the output voltage of the power battery pack.

[0062] For example, the battery module may be a battery module composed of multiple battery cells. Alternatively, the battery module may be a battery pack formed by encapsulating multiple battery cells. Alternatively, the battery module may be composed of multiple battery cells directly encapsulated in a chassis. It should be understood that this is merely an example and does not constitute a limitation on the embodiments of the present application.

[0063] The present application provides a battery module detection system and method thereof, which can detect insulation abnormalities inside the battery module and ensure the safety and stability of the battery module.

[0064] In an embodiment of the present application, the battery module detection system can detect insulation anomalies inside the battery module, locate the battery module with insulation anomalies, and is conducive to timely warning when insulation anomalies occur inside the battery module, thereby ensuring the safety and effectiveness of the battery module power battery pack and the vehicle. Among them, the battery module detection system includes a control circuit and a detection circuit, and the detection circuit is connected to the control circuit and the battery module to be detected respectively. Furthermore, the above-mentioned control circuit can generate and transmit a power supply voltage to the detection circuit, and the above-mentioned detection circuit includes a resistor unit. The detection circuit generates a detection voltage based on the resistor unit, the power supply voltage and the battery module; the detection circuit can feed back the generated detection voltage to the control circuit. The control circuit calculates the detection parameters inside the battery module based on the received detection voltage, the generated power supply voltage and the resistance value of the above-mentioned resistor unit. It can be understood that the detection parameter can be understood as a parameter used to characterize the insulation anomaly between the multiple battery cells inside the battery module and the outer shell of the battery module. Therefore, the control circuit can determine the insulation abnormality inside the battery module based on the above-mentioned detection parameters, which is conducive to timely early warning when there is insulation abnormality inside the battery module, and then it can facilitate maintenance personnel to check the abnormality of the battery module, ensuring the safety and effectiveness of the battery module power battery pack and vehicle.

[0065] In some feasible embodiments, please refer to Figure 1, which is a schematic structural diagram of a power battery pack provided in an embodiment of the present application. As shown in Figure 1, the power battery pack 100 includes a housing 110 and multiple battery modules. The housing 110 serves as a protective structure for the power battery pack 100 and can fix and support the multiple battery modules therein. The multiple battery modules include battery module 120 and battery module 130, and the multiple battery modules are connected in series via BC poles. The BC poles can be understood as connection terminals for connecting external conductors to the battery modules. For example, the BC poles of battery module 130 are connected to the BC poles of battery module 120, thereby electrically connecting battery module 130 to battery module 120. Furthermore, each battery module in Figure 1 includes a housing and multiple battery cells BT1, BT2, BT3, etc., which are connected in series. The housing of the battery module is used to encapsulate and protect the multiple battery cells within the battery module, thereby preventing short circuits between different battery modules and affecting the normal operation of the power battery pack 100. It can be understood that the voltage of each of the above-mentioned battery modules is equal to the sum of the voltages of the multiple battery cells connected in series within the battery module. Similarly, the voltage of the power battery pack 100 is equal to the sum of the voltages of the multiple battery modules connected in series within the power battery pack 100.

[0066] In some feasible embodiments, the outer shell 110 of the power battery pack 100 is insulated from the multiple battery modules, which can prevent the outside world from interfering with the multiple battery modules inside the power battery pack 100. For example, in the case of a humid external environment, a high temperature, etc., the outer shell 110 can keep the multiple battery modules safe and effective by being insulated from the multiple battery modules. Similarly, the outer shell of each of the above-mentioned battery modules is insulated from the multiple battery cells inside the battery module, which can prevent the outside world from causing adverse effects on the multiple internal battery cells, and at the same time prevent mutual interference between different battery modules. For example, assuming that a battery cell of the battery module 120 in Figure 1 fails, since the battery module 120 is insulated from the battery module 130 through its outer shell 140, and the battery module 130 is insulated from the battery module 120 through its outer shell 150, the failure of the battery module 120 will not affect the normal operation of the battery module 130.

[0067] It should be noted that when an insulation abnormality occurs in the battery module or battery cell inside the power battery pack, the insulation performance between the power battery pack shell and the battery module will be reduced, which in turn affects the safety and stability of the power battery pack. Among them, the insulation performance between the power battery pack shell and the battery module can be understood as the resistance value of the equivalent insulation resistance between the power battery pack shell and the battery module. Furthermore, the equivalent insulation resistance between the power battery pack shell and the battery module refers to the ratio of the voltage applied between the power battery pack shell and the battery module to the current flowing from the shell to the battery module or from the battery module to the shell. When the shell and the battery module are completely insulated, the resistance value of the above-mentioned equivalent insulation resistance is infinite. When the insulation performance between the battery and the battery module is reduced, the resistance value of the above-mentioned equivalent insulation resistance decreases, that is, the smaller the resistance value of the equivalent insulation resistance, the worse the insulation performance.

[0068] Similarly, the insulation performance between the outer shell of the battery module and the internal battery cells can also be characterized by the equivalent insulation resistance between the outer shell of the battery module and the internal battery cells.

[0069] In some feasible implementations, when one or more battery modules leak and the liquid seeps outside the battery module, the leaked liquid can cause the insulation between the power battery pack casing and the battery module to no longer be effective, resulting in a degradation of insulation performance. To ensure the safety and stability of the power battery pack, the equivalent insulation resistance between the power battery pack casing and the battery module can be tested.

[0070] In some feasible embodiments, the equivalent insulation resistance between the outer shell of the power battery pack and the multiple battery modules can be characterized by the resistance between the busbar of the power battery pack and the outer shell. The busbar of the power battery pack can be understood as the busbar used to power or charge the power battery pack. For ease of understanding, the present embodiment is illustrated with reference to the power battery pack 200 in Figure 2.

[0071] Please refer to Figure 2, which is another structural schematic diagram of the power battery pack provided in an embodiment of the present application. As shown in Figure 2, the total negative busbar of the power battery pack 200 is connected to the BC pole of the battery module 220, which is equivalent to the negative pole of the power battery pack 200; the total positive busbar of the power battery pack 200 is connected to the BC pole of the battery module 230, which is equivalent to the positive pole of the power battery pack 200. In addition, the power battery pack 200 also includes a resistor Ra, a resistor Rb, a resistor Rc and a resistor Rd connected in series. The equivalent insulation resistance between the outer shell 210 of the power battery pack 200 and the multiple battery modules can be characterized by the resistance Rp between the total positive busbar of the power battery pack 200 and the outer shell 210, and the resistance Rn between the total negative busbar and the outer shell 210. To this end, the power battery pack 200 can detect the above-mentioned resistance Rp and resistance Rn through the insulation detection circuit 240 to determine the equivalent insulation resistance between the shell 210 and the battery module 220 or the battery module 230, and then timely issue an early warning when one or more battery modules in the power battery pack 200 have insulation abnormalities.

[0072] However, as the packaging technology of battery modules continues to upgrade and iterate, the battery cells inside the battery module usually do not affect the outside of the battery module when a fault occurs. For example, when a battery cell inside the battery module leaks, the leaked liquid will usually only remain inside the battery module, causing the insulation performance inside the battery module to degrade, and will not penetrate to the outside of the battery module, and will not affect the insulation performance between the power battery pack shell and the battery module. It is understandable that the insulation detection circuit 240 shown in Figure 2 can only be used to detect the equivalent insulation resistance between the shell 210 of the power battery pack 200 and multiple battery modules, and cannot detect the insulation performance inside any battery module. As a result, when an abnormality occurs in the battery cell inside the battery, causing the insulation performance inside the battery module to degrade, it is impossible to issue a timely warning, posing a safety hazard.

[0073] Based on the above-mentioned technical problems, an embodiment of the present application provides a battery module detection system that can detect the insulation performance inside the battery module, so as to provide timely warning when insulation abnormalities occur in the battery module cells, resulting in a decrease in the equivalent insulation resistance between the battery module casing and the cells, thereby improving the safety and stability of the power battery pack.

[0074] In some feasible embodiments, please refer to Figure 3, which is a structural schematic diagram of a battery module detection system provided in an embodiment of the present application. The battery module detection system 300 shown in Figure 3 is arranged in a power battery pack 310, and is used to detect insulation abnormalities inside the battery module 320 in the power battery pack 310. The battery module 320 includes multiple cells such as battery cell BT1, battery cell BT2, battery cell BT3, etc. Furthermore, the insulation abnormality inside the battery module 320 can be understood as a situation where one or more of the multiple cells inside the battery module 320 have an abnormality, causing the battery module 320 to fail to operate normally. For example, in the case of leakage in the battery cell BT1, the equivalent insulation resistance between the battery cell BT1 and the outer shell 330 of the battery module 320 decreases, that is, the battery cell BT1 has an abnormality. Alternatively, in the case of arcing in the battery cell BT2, the equivalent insulation resistance between the battery cell BT2 and the above-mentioned outer shell 330 will also decrease, that is, the battery cell BT2 has an abnormality. Alternatively, in the event of a micro-short circuit in the battery cell BT3, the equivalent insulation resistance between the battery cell BT3 and the above-mentioned housing 330 will also decrease, that is, an abnormality has occurred in the battery cell BT2. Any abnormality in any of the battery cells in the above-mentioned battery module 320 will cause the battery module 320 to not operate normally, that is, an insulation abnormality has occurred inside the battery module 320. It should be noted that the insulation abnormalities of the above-mentioned battery cell leakage, arcing, and micro-short circuits are only examples. Other insulation abnormalities may also occur in the battery module 320, and this application will not illustrate them one by one here.

[0075] In some feasible implementations, the battery module detection system 300 of the embodiment of the present application can obtain detection parameters within the battery module 320 by detecting the battery module 320. The detection parameters within the battery module 320 can be understood as parameters used to characterize whether there is a battery cell operating abnormality within the battery module 320. The battery module detection system 300 can then determine whether there is a battery cell operating abnormality within the battery module 320 based on the detection parameters, and further determine the insulation abnormality within the battery module 320.

[0076] In other words, the battery module detection system 300 can first obtain detection parameters within the battery module 320, and then determine the insulation abnormality within the battery module 320 based on the detection parameters. For ease of understanding, the embodiment of the present application explains the specific process of obtaining the detection parameters within the battery module 320 in the following.

[0077] It should be noted that when an insulation abnormality occurs inside the battery module 320, the voltage inside the battery module 320 will also change. For example, under normal circumstances, the multiple cells of the battery module 320 are insulated from the outer shell 330, then the voltage inside the battery module 320 is distributed between the multiple cells connected in series, and the outer shell 330 is not charged, that is, the voltage of the outer shell 330 is 0. When the cell BT1 of the battery module 320 leaks, the cell BT1 is electrically connected to the above-mentioned outer shell 330 through the leaked liquid, then the voltage inside the battery module 320 is distributed between the outer shell 330 and the multiple cells connected in series. At this time, the outer shell 330 is charged, and the voltage of the outer shell 330 is no longer 0. In other words, the voltage inside the battery module 320 can be used to characterize the insulation abnormality inside the battery module 320. Therefore, the battery module detection system 300 of the embodiment of the present application can detect the voltage change inside the battery module 320, so as to use the voltage change inside the battery module 320 as the above-mentioned detection parameter.

[0078] In some feasible embodiments, the battery module detection system 300 includes a control circuit 301 and a detection circuit 302, wherein the detection circuit 302 is connected to the battery module 320 and the control circuit 301, respectively. As can be seen from the above, when the voltage distribution within the battery module 320 changes, the voltage of the outer shell 330 of the battery module 320 will also change. That is, the voltage change of the outer shell 330 can reflect the voltage change within the battery module 320. Therefore, the battery module detection system 300 can be connected to the outer shell 330 of the battery module 320 via the detection circuit 302. When an insulation abnormality occurs within the battery module 320, causing the voltage of the outer shell 330 to change, detection parameters can be obtained, and the insulation abnormality within the battery module 320 can be determined based on the detection parameters.

[0079] In some feasible embodiments, the above-mentioned detection circuit 302 can also receive the power supply voltage generated by the control circuit 301 while detecting the internal voltage of the battery module 320. Furthermore, when the internal voltage of the battery module 320 changes, causing the voltage of the outer shell 330 to also change, the detection circuit 302 can generate a corresponding detection voltage under the action of the voltage of the outer shell 330 and the power supply voltage. It should be noted that the detection circuit 302 includes a resistor unit, which can generate different detection voltages under the action of different voltages of the outer shell 330 and the power supply voltage. Therefore, the detection circuit 302 can feed back the detection voltage to the control circuit 301, so that the control circuit 301 can infer the internal voltage of the battery module 320 based on the generated power supply voltage, the received detection voltage and the resistance value of the resistor unit in the detection circuit 302, and then determine the insulation abnormality inside the battery module 320.

[0080] In some feasible embodiments, the control circuit 301 can receive a power supply signal and operate based on the power supply signal. The power supply signal can be understood as the DC operating voltage of the control circuit 301. For example, assuming that the DC operating voltage of the control circuit 301 is 3.3 volts, the control circuit 301 can receive a 3.3 volt DC voltage as the power supply signal. It is understood that the power supply signal can be provided to the control circuit 301 by an external DC power supply, which is not limited in this application. Furthermore, the control circuit 301 can generate a power supply voltage based on the power supply signal. Specifically, the control circuit 301 can amplify the power supply signal according to a preset amplification factor to generate the power supply voltage. The amplification factor can be an integer or fraction greater than 0. For example, if the power supply signal of the control circuit 301 is 3.3 volts, when the power supply voltage is also 3.3 volts, the control circuit 301 can preset the amplification factor to 1, and then amplify the power supply signal according to the amplification factor to generate a 3.3 volt power supply voltage. Similarly, when the power supply voltage is at other values, the preset amplification factor can be changed to generate a corresponding power supply voltage. This power supply voltage is then transmitted to the detection circuit 302, so that the detection circuit 302 generates a corresponding detection voltage under the influence of the power supply voltage and the voltage of the housing 330, and feeds it back to the control circuit 301.

[0081] In some feasible embodiments, it can be seen from the above content that the insulation performance between the outer shell 330 of the battery module 320 and the multiple internal battery cells can be characterized by the insulation resistance inside the battery module 320. Among them, the insulation resistance inside the battery module 320 can be understood as the equivalent resistance between the multiple battery cells inside the battery module 320 and the outer shell 330. For example, when there is no abnormal operation of the battery cells in the battery module 320, the multiple battery cells in the battery module 320 are insulated from the outer shell 330, and the equivalent resistance between the multiple battery cells and the outer shell 330 is infinite, that is, the insulation resistance inside the battery module 320 is infinite. When the battery cell BT1 in the battery module 320 operates abnormally, the equivalent resistance between the battery cell BT1 and the outer shell 330 decreases, and the insulation resistance inside the battery module 320 decreases. Therefore, the battery module detection system 300 in the embodiment of the present application can determine the insulation abnormality between the multiple battery cells in the battery module 320 and the outer shell 330 by detecting the insulation resistance between the outer shell 330 and the internal battery cells.

[0082] In some feasible embodiments, when the above-mentioned detection parameter includes the insulation resistance inside the battery module 320, the control circuit 301 can amplify the power supply signal according to a preset amplification factor to generate a first power supply voltage, and then transmit the first power supply voltage to the detection circuit 302. The detection circuit 302 can generate the first detection voltage under the influence of the first power supply voltage and the voltage of the housing 330, and feed it back to the above-mentioned control circuit 301. Furthermore, after receiving the first detection voltage, the control circuit 301 combines the above-mentioned first power supply voltage, the first detection voltage, and the resistance value of the resistance unit in the detection circuit 302 to calculate the insulation resistance inside the battery module 320.

[0083] In some feasible implementations, in order to facilitate understanding of the principle of the above control circuit calculating the insulation resistance according to the above method, the embodiment of the present application is described in detail with reference to FIG. 4 .

[0084] Specifically, please refer to Figure 4, which is a structural diagram of a detection circuit provided in an embodiment of the present application. As shown in Figure 4, the resistance unit of the detection circuit 400 includes a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4 and a fifth resistor R5. Among them, one end of the above-mentioned first resistor R1 is connected to the first port a1 of the control circuit 410, and the other end of the above-mentioned first resistor R1 is respectively connected to one end of the second resistor R2, one end of the third resistor R3 and one end of the fourth resistor R4, the other end of the above-mentioned second resistor R2 is connected to the second port a2 of the control circuit 410, the other end of the above-mentioned third resistor R3 is grounded, and the other end of the above-mentioned fourth resistor R4 is respectively connected to the other end of the third resistor R3 and one end of the fifth resistor R5, and the other end of the above-mentioned fifth resistor R5 is connected to the housing 430 of the battery module 420.

[0085] It is understood that after generating the first power supply voltage, the control circuit 410 can transmit the first power supply voltage to the detection circuit 400 through the first port a1. The detection circuit 400 is connected to the housing 430 and can generate a corresponding first detection signal under the influence of the voltage of the housing 430 and the first power supply voltage. As can be seen from the above, the first detection voltage is related to the first power supply voltage, the voltage inside the battery module 420, and the resistance values ​​of the above-mentioned resistors. Furthermore, the detection circuit 400 can feedback the first detection voltage to the control circuit 410 through the second port a2 of the control circuit 410.

[0086] In some feasible implementations, the first detection voltage U1 can be represented by the following formula (1):

[0087] Among them, R is the resistance of the insulation resistance inside the battery module 420, U1 is the first detection voltage, V1 is the first power supply voltage, R1 is the resistance of the first resistor, R2 is the resistance of the second resistor, R3 is the resistance of the third resistor, R4 is the resistance of the fourth resistor, and R5 is the resistance of the fifth resistor.

[0088] In some feasible implementations, the control circuit 410 may be configured to calculate the insulation resistance R inside the battery module 420 according to the following formula (2) after receiving the first detection voltage U1 fed back by the detection circuit 400:

[0089] Among them, R is the resistance of the insulation resistance inside the battery module 420, U1 is the first detection voltage, V1 is the first power supply voltage, R1 is the resistance of the first resistor, R2 is the resistance of the second resistor, R3 is the resistance of the third resistor, R4 is the resistance of the fourth resistor, and R5 is the resistance of the fifth resistor.

[0090] In general, the control circuit 410 can generate and transmit a first power supply voltage to the detection circuit 400, and receive a first detection signal fed back by the detection circuit 400, and then calculate the insulation resistance inside the battery module 420, that is, the above-mentioned detection parameters, based on the first power supply voltage, the first detection signal and the resistance values ​​of the resistance units in the detection circuit 400, and then determine the insulation abnormality between the multiple battery cells inside the battery module 420 and the outer shell 430 of the battery module 420 based on the detection parameters.

[0091] In some feasible embodiments, the control circuit 410 shown in FIG4 can calculate the insulation resistance inside the battery module 420 according to the above formula (2), and can also calculate the above insulation resistance according to the following method. In this case, the control circuit 410 can generate a first power supply voltage and a second power supply voltage according to a preset magnification factor, and then transmit the first power supply voltage and the second power supply voltage to the detection circuit 400 respectively. The detection circuit 400 can generate a first detection voltage under the action of the first power supply voltage and the voltage of the shell 430, and feed it back to the above control circuit 410. The detection circuit 400 can also generate a second detection voltage under the action of the second power supply voltage and the voltage of the shell 430, and feed it back to the above control circuit 410. Further, after receiving the first detection voltage and the second detection voltage, the control circuit 410 combines the first power supply voltage, the second power supply voltage, the first detection voltage, the second detection voltage and the resistance value of the resistance unit in the detection circuit 400 to calculate the insulation resistance inside the battery module 420.

[0092] In some feasible implementations, in order to facilitate understanding of the principle of the control circuit 410 calculating the insulation resistance according to the above method, the embodiment of the present application is described in detail with reference to FIG. 4 .

[0093] Specifically, referring again to FIG. 4 , after generating a first power supply voltage, the control circuit 410 shown in FIG. 4 can transmit this first power supply voltage to the detection circuit 400 via the first port a1. The detection circuit 400 is connected to the housing 430 and can generate a corresponding first detection signal in response to the voltage of the housing 430 and the first power supply voltage. As can be seen from the above, the first detection voltage is related to the first power supply voltage, the voltage within the battery module 420, and the resistance values ​​of the aforementioned resistors. Furthermore, the detection circuit 400 can feedback the first detection voltage via the second port a2 of the control circuit 410. Then, after receiving the first detection voltage, the control circuit 410 can generate a second power supply voltage and transmit this second power supply voltage to the detection circuit 400 via the first port a1. The detection circuit 400 can generate a corresponding second detection signal in response to the voltage of the housing 430 and the second power supply voltage. As can be seen from the above, the second detection voltage is related to the second power supply voltage, the voltage within the battery module 420, and the resistance values ​​of the aforementioned resistors. Furthermore, the detection circuit 400 may feed back the second detection voltage through the second port a2 of the control circuit 410 .

[0094] It should be noted that, in some feasible implementations, the first detection voltage fed back by the detection circuit 400 can be represented by the above formula (3):

[0095] Wherein, U1 is the first detection voltage, V1 is the first power supply voltage, R1 is the resistance of the first resistor, R2 is the resistance of the second resistor, R3 is the resistance of the third resistor, R4 is the resistance of the fourth resistor, R5 is the resistance of the fifth resistor, U x is the voltage inside the battery module 420.

[0096] Similarly, the second detection voltage can be represented by the following formula (4):

[0097] Wherein, U2 is the second detection voltage, V2 is the second power supply voltage, R1 is the resistance value of the first resistor, R2 is the resistance value of the second resistor, R3 is the resistance value of the third resistor, R4 is the resistance value of the fourth resistor, R5 is the resistance value of the fifth resistor, U x is the voltage inside the battery module 420.

[0098] In some feasible embodiments, the control circuit 410 may be configured to calculate the insulation resistance R inside the battery module 420 according to the following formula (5) after receiving the first detection voltage U1 and the second detection voltage U2 fed back by the detection circuit 400:

[0099] Among them, R is the resistance of the insulation resistance inside the battery module 420, U1 is the first detection voltage, U2 is the second detection voltage, V1 is the first power supply voltage, V2 is the second power supply voltage, R1 is the resistance of the first resistor, R2 is the resistance of the second resistor, R3 is the resistance of the third resistor, R4 is the resistance of the fourth resistor, and R5 is the resistance of the fifth resistor.

[0100] In general, the control circuit can generate and transmit a first power supply voltage and a second power supply voltage to the detection circuit respectively, and receive a first detection signal and a second detection signal respectively fed back by the detection circuit, and then calculate the insulation resistance inside the battery module, that is, the above-mentioned detection parameters, based on the first power supply voltage, the second power supply voltage, the first detection signal, the second detection signal and the resistance values ​​of the resistance units in the detection circuit, and then determine the insulation abnormality between the multiple battery cells inside the battery module and the outer casing of the battery module based on the detection parameters.

[0101] In some feasible embodiments, after the control circuit calculates the insulation resistance inside the battery module according to the above content, it can further determine the insulation abnormality between the multiple battery cells inside the battery module and the outer shell based on the preset resistance threshold and the comparison result of the insulation resistance. Specifically, the above resistance threshold can be understood as the minimum value of the insulation resistance inside the battery module when there is no insulation abnormality inside the battery module. That is to say, when the insulation resistance inside the battery module is less than the resistance threshold, it indicates that there is an insulation abnormality inside the battery module at this time. For example, in some application scenarios, the resistance threshold can be 1 megohm. When the insulation resistance calculated by the control circuit is less than 1 megohm, the control circuit can determine that there is an insulation abnormality between the multiple battery cells inside the battery module and the outer shell.

[0102] It can be understood that when there are multiple battery modules in the power battery pack, the above-mentioned battery module detection system connected to each battery module can be used to detect the detection parameters (such as the above-mentioned insulation resistance) inside the multiple battery modules to determine the battery module where the insulation abnormality occurs, thereby facilitating the repair and replacement of the faulty battery module.

[0103] In some feasible embodiments, the battery module detection system provided in the embodiments of the present application can not only identify the battery modules with insulation abnormalities in the power battery pack, but also identify the abnormally functioning battery cells in the battery modules with insulation abnormalities, so that maintenance personnel can directly repair and replace the abnormally functioning battery cells in the battery modules, thereby saving maintenance costs.

[0104] Specifically, please refer again to Figure 4 . As shown in Figure 4 , the battery module 420 includes multiple battery cells: battery cell BT1, battery cell BT2, and battery cell BT3. The positive electrode of battery cell BT1 is connected to the negative electrode of battery cell BT2 at point a, the positive electrode of battery cell BT2 is connected to the negative electrode of battery cell BT3 at point b, and the positive electrode of battery cell BT3 is connected to the BC column of battery module 420 at point c. It should be noted that because these multiple battery cells are connected in series, the voltage distribution at points a, b, and c conforms to the distribution characteristics of a series battery circuit. Therefore, when the battery module 420 is operating normally, the normal voltage at point c > the normal voltage at point b > the normal voltage at point a. For example, if the output voltage of each of these multiple battery cells is 5 volts, the normal voltage at point a equals the output voltage of cell BT1 (5 volts), the normal voltage at point b equals the combined output voltage of cells BT1 and BT2 (10 volts), and the normal voltage at point c equals the combined output voltage of cells BT1, BT2, and BT3 (15 volts).

[0105] It is understandable that when the multiple cells of the battery module 420 are not abnormal, the multiple cells are insulated from the shell 430. At this time, the output voltage of the multiple cells is not loaded on the shell 430, and the voltage of the shell 430 is less than the preset shell voltage threshold. The shell voltage threshold can be understood as the minimum voltage when the shell 430 is charged. The voltage of the shell 430 is greater than the shell voltage threshold, which indicates that the shell 430 is charged. It is understandable that when the cell of the battery module 420 is working abnormally, the cell with abnormal operation is no longer insulated from the shell 430, that is, the cell with abnormal operation will transmit the output voltage to the shell 430 through the insulation resistance. For example, when the cell BT1 has abnormalities such as leakage or micro-short circuit, the cell BT1 will be electrically connected to the shell 430 of the battery module 420 through the insulation resistance R, which can be equivalent to the output voltage of the cell BT1 (that is, the normal voltage at point a) acting on the shell 430 through the insulation resistance. Similarly, when the battery cell BT2 has abnormalities such as leakage or micro-short circuit, the battery cell BT2 will be electrically connected to the outer shell 430 of the battery module 420 through the insulation resistance R, which can be equivalent to the output voltage of the battery cell BT1 and the battery cell BT2 (i.e., the normal voltage at point b) acting on the outer shell 430 through the insulation resistance. When the battery cell BT3 has abnormalities such as leakage or micro-short circuit, the battery cell BT3 will be electrically connected to the outer shell of the battery module 420 through the insulation resistance R, which can be equivalent to the output voltage of the battery cell BT1, the battery cell BT2 and the battery cell BT3 (i.e., the normal voltage at point c) acting on the outer shell 430 through the insulation resistance. That is to say, when abnormalities occur in different battery cells in the battery module 420, the corresponding voltages acting on the outer shell 430 are also different. To this end, the battery module detection system of the embodiment of the present application can calculate the voltage acting on the outer shell 430 inside the battery module 420 by detecting the battery module 420, and determine the voltage as the insulation voltage U of the battery module 420. x The insulation voltage U x It can be understood that when an insulation abnormality occurs in a battery cell in the battery module 420, the abnormally functioning battery cell causes the housing 430 to have a certain voltage, such as the output voltage of the above-mentioned battery cell BT1 or the common output voltage of the battery cell BT1 and the battery cell BT2.

[0106] In some feasible embodiments, to determine whether an insulation abnormality has occurred in the battery module 420 and to identify the abnormally functioning battery cell in the abnormal battery module 420, the control circuit 410 may calculate the insulation voltage and insulation resistance within the battery module 420 based on the power supply voltage, the detection voltage, and the resistance value of the resistor unit. That is, the detection parameters within the battery module 420 include the insulation voltage and insulation resistance. Whether an insulation abnormality has occurred within the battery module 420 is then determined based on the insulation resistance, and the battery cell within the battery module 420 with the insulation abnormality is then identified based on the insulation equivalent voltage.

[0107] It is understandable that the specific implementation method of the above-mentioned control circuit 410 calculating the insulation resistance inside the battery module 420 can be found in the above content, and this application will not go into details here. Furthermore, after the control circuit 410 calculates the insulation resistance inside the battery module 420, it can be seen from the above content that when the insulation resistance is less than the preset resistance threshold, it can be determined that there is an insulation abnormality between the multiple battery cells inside the battery module 420 and the shell 430, that is, there is an abnormality in the operation of the multiple battery cells inside the battery module 420. Furthermore, the control circuit 410 can calculate the insulation voltage inside the battery module 420 based on the above-mentioned power supply voltage, detection voltage and the resistance value of the resistance unit of the detection circuit 400.

[0108] Specifically, when the resistance unit of the detection circuit 400 is shown in Figure 4, the control circuit 410 can calculate the above-mentioned insulation voltage according to the following content. First, after generating the first power supply voltage, the control circuit 410 can transmit the first power supply voltage to the detection circuit 400 through the first port a1. The detection circuit 400 is connected to the housing 430 and can generate a corresponding first detection signal under the action of the voltage of the housing 430 and the first power supply voltage. As can be seen from the above content, the first detection voltage is related to the above-mentioned first power supply voltage, the voltage inside the battery module 420, and the resistance values ​​of the above-mentioned resistors. Furthermore, the detection circuit 400 can feedback the first detection voltage through the second port a2 of the control circuit 410. Then, after receiving the first detection voltage, the control circuit 410 can generate a second power supply voltage and transmit the second power supply voltage to the detection circuit 400 through the first port a1. The detection circuit 400 can generate a corresponding second detection signal under the action of the voltage of the housing 430 and the second power supply voltage. As can be seen from the above, the second detection voltage is related to the second power supply voltage, the voltage inside the battery module 420 and the resistance values ​​of the resistors. Furthermore, the detection circuit 400 can feed back the second detection voltage through the second port a2 of the control circuit 410.

[0109] It should be noted that the first detection voltage fed back by the detection circuit 400 can be represented by the above formula (3), and the second detection voltage can be represented by the above formula (4), which will not be elaborated herein.

[0110] In some feasible embodiments, the control circuit 410 may be configured to calculate the insulation voltage U inside the battery module 420 according to the following formula (6) after receiving the first detection voltage U1 and the second detection voltage U2 fed back by the detection circuit 400: x :

[0111] Among them, U xis the insulation voltage, U1 is the first detection voltage, U2 is the second detection voltage, V1 is the first power supply voltage, V2 is the second power supply voltage, R1 is the resistance of the first resistor, R2 is the resistance of the second resistor, R3 is the resistance of the third resistor, R4 is the resistance of the fourth resistor, and R5 is the resistance of the fifth resistor.

[0112] It is understandable that when multiple cells in the battery module 420 are operating normally, the multiple cells are insulated from the outer shell 430. At this time, the insulation voltage calculated by the control circuit 410 is less than the preset insulation voltage threshold. The insulation voltage threshold can be understood as the minimum value of the insulation voltage and the voltage acting on the outer shell when the cells in the battery module 420 are operating abnormally. In other words, when the insulation voltage calculated by the control circuit 410 is less than the above-mentioned insulation voltage threshold, it can be determined that there is no abnormal cell operation in the battery module 420. Further, when the insulation voltage calculated by the control circuit 410 is greater than the above-mentioned insulation voltage threshold, it can be determined that there is an abnormal cell operation in the battery module 420, and the abnormal cell is no longer insulated from the outer shell 430, that is, the abnormal cell will apply the output voltage to the outer shell 430 through the insulation resistance. Therefore, the control circuit 410 can determine the abnormal cell based on the calculated insulation voltage and the output voltages corresponding to the multiple cells.

[0113] Specifically, the control circuit 410 can pre-set multiple voltage threshold intervals. It should be noted that the above-mentioned preset multiple voltage threshold intervals can be understood as multiple voltage threshold intervals corresponding to multiple battery cells in the battery module 420. For example, the battery module 420 shown in Figure 4 includes battery cell BT1, battery cell BT2 and battery cell BT3. It can be seen from the above that when the output voltages of the above-mentioned multiple battery cells are all 5 volts, when the battery cell BT1 has an insulation abnormality, the output voltage of the battery cell BT1 acts on the housing 430 through the insulation resistance, and the calculated insulation voltage at this time is close to the output voltage of the battery cell BT1 of 5 volts. Therefore, the control circuit 410 can determine the voltage threshold interval corresponding to the battery cell BT1 as an interval with an average of 5 volts, for example, 3 volts to 7 volts. It can be understood that when the insulation voltage of the battery module 420 is calculated to be equal to 6 volts, it can be determined that the battery cell BT1 of the battery module 420 is abnormal.

[0114] Similarly, when the battery BT2 has an insulation abnormality, the battery cell BT2 is connected in series with the battery cell BT1, and the output voltages of the battery cells BT1 and BT2 are added together and act on the housing 430 through the insulation resistance. At this time, the calculated insulation voltage is close to the sum of the output voltages of the battery cells BT1 and BT2, which is 10 volts. Therefore, the control circuit 410 can determine the voltage threshold interval corresponding to the battery cell BT2 as an interval with an average value of 10 volts, for example, 8 volts to 12 volts. It is understandable that when the insulation voltage of the battery module 420 is calculated to be equal to 9 volts, it can be determined that the battery cell BT2 of the battery module 420 is abnormal.

[0115] Similarly, when the battery BT3 has an insulation abnormality, the battery cell BT3 is connected in series with the battery cell BT2 and the battery cell BT1. The output voltages of the battery cells BT1, BT2 and BT3 are added together and act on the housing 430 through the insulation resistance. At this time, the calculated insulation voltage is close to the sum of the output voltages of the battery cells BT1, BT2 and BT3, which is 15 volts. Therefore, the control circuit 410 can determine the voltage threshold interval corresponding to the battery cell BT3 as an interval with an average value of 15 volts, for example, 13 volts to 17 volts. It can be understood that when the insulation voltage of the battery module 420 is calculated to be equal to 14 volts, it can be determined that the battery cell BT3 of the battery module 420 is abnormal.

[0116] In general, the control circuit 410 can determine the voltage threshold interval corresponding to each battery cell based on the output voltage of each battery cell connected in series within the battery module 420. The voltage threshold intervals of the above-mentioned battery cell BT1, battery cell BT2, and battery cell BT3 are only used as examples, and this application does not illustrate them one by one. It should be noted that in order to avoid errors in judging abnormal battery cells, the control circuit 410 should ensure that the voltage threshold intervals corresponding to each battery cell do not overlap when pre-setting the voltage threshold intervals corresponding to each battery cell.

[0117] It can be understood that after the control circuit 410 calculates the insulation voltage inside the battery module 420, it can determine a voltage threshold interval corresponding to the insulation voltage in the preset multiple voltage threshold intervals as the target voltage threshold interval. The target voltage threshold interval can be understood as a voltage threshold interval including the calculated insulation voltage. For example, assuming that the voltage threshold interval corresponding to the battery cell BT1 is 3 volts to 7 volts, when the control circuit 410 calculates the insulation voltage to be 7 volts, it can be determined that the voltage threshold interval corresponding to the battery cell BT1 is 3 volts to 7 volts as the above-mentioned target voltage threshold interval. Furthermore, the control circuit 410 can determine the battery cell corresponding to the target voltage threshold interval as a battery cell with an insulation abnormality, that is, determine the above-mentioned battery cell BT1 as a battery cell with an insulation abnormality.

[0118] In some feasible implementations, please refer to Figure 5, which is another structural diagram of the detection circuit provided in an embodiment of the present application. As shown in Figure 5, the detection circuit 500 also includes a first capacitor C1 and a second capacitor C2. Wherein, the first capacitor C1 is connected in parallel with the above-mentioned third resistor R3, one end of the second capacitor C2 is connected to the other end of the fourth resistor R4, and the other end of the second capacitor C2 is grounded. It should be noted that the above-mentioned first capacitor C1 is a filter capacitor, which can filter out the interference signal in the detection circuit 500 to avoid interference with the detection parameters. The second capacitor C2 is a parasitic capacitor in the detection circuit 500.

[0119] In some feasible embodiments, please refer to Figure 5 again. The detection circuit 500 shown in Figure 5 further includes a first diode D1 and a second diode D2. One end of the first diode D1 is connected to the first port a1 of the control circuit, and the other end of the first diode D1 is connected to one end of the second resistor R2. One end of the second diode D2 is connected to the second port a2 of the control circuit, and the other end of the second diode D2 is grounded. It should be noted that the first diode D1 can be a reverse diode to prevent the voltage in the detection circuit 500 from affecting the first port a1 of the control circuit. The second diode D2 can be a voltage-stabilizing diode to prevent the voltage in the detection circuit 500 from affecting the second port a2 of the control circuit. This ensures the stability of the detection circuit 500.

[0120] In some feasible implementations, as can be seen from the above, the detection circuit in the battery module detection system is composed of resistors and capacitors (resistors and capacitors), which has a simple structure and is easy to implement. In addition, the cost of resistors and capacitors is low, which can save development costs.

[0121] In an embodiment of the present application, when a power battery pack includes multiple battery modules, the insulation resistance of the multiple battery modules can be detected separately by a battery module detection system connected to each battery module, so as to determine the insulation abnormality inside the multiple battery modules based on the insulation resistance and a preset resistance threshold, and then determine the battery module with insulation abnormality among the multiple battery modules. Furthermore, the battery module with insulation abnormality can be repaired and replaced. It is understandable that when it is determined that a battery module has an insulation abnormality, the battery module detection system can also calculate the insulation voltage of the battery module, and then determine the battery cell with insulation abnormality among the multiple cells of the battery module based on the insulation voltage of the battery module and a plurality of preset voltage threshold intervals, so as to facilitate maintenance personnel to repair and replace abnormal cells in the battery module, thereby improving the safety and stability of the battery module.

[0122] The present application also provides a battery module detection method. Please refer to Figure 6, which is a flow chart of the battery module detection method provided by the present application. The battery module detection method provided by the present application is applicable to the battery module detection system shown in Figures 3 to 5. It should be noted that the detection method shown in Figure 6 can be executed by the control circuit shown in Figures 3 to 5 above. Specifically, the battery module detection method may include at least the following steps:

[0123] S101 , controlling the power supply voltage to be transmitted to the detection circuit, and obtaining the detection voltage fed back by the detection circuit.

[0124] In some feasible embodiments, the detection circuit includes a resistor unit. Furthermore, as can be seen from the above, the detection circuit can receive a power supply voltage generated by the control circuit. When the voltage within the battery module changes, causing the voltage of the outer casing to also change, the detection circuit can generate a corresponding detection voltage under the influence of the outer casing voltage and the power supply voltage.

[0125] The specific implementation of the above S101 can refer to the implementation performed by the control circuit in Figures 3 to 5 above, and the embodiments of the present application will not be repeated here.

[0126] S102 : Determine detection parameters inside the battery module according to the power supply voltage, the detection voltage, and the resistance value of the resistance unit, and determine whether there is an insulation abnormality inside the battery module according to the detection parameters inside the battery module.

[0127] In some feasible embodiments, the resistor unit can generate different detection voltages under the influence of different housing voltages and power supply voltages. Therefore, the detection circuit can feed back the detection voltage to the control circuit, which can then infer the internal voltage of the battery module based on the generated power supply voltage, the received detection voltage, and the resistance value of the resistor unit in the detection circuit, thereby determining the insulation abnormality inside the battery module.

[0128] In some feasible implementations, the battery module detection system in the embodiment of the present application can determine the insulation abnormality between multiple battery cells in the battery module and the outer shell by detecting the insulation resistance between the outer shell and the internal battery cells.

[0129] In some feasible embodiments, when the above-mentioned detection parameters include the insulation resistance inside the battery module, the control circuit can amplify the power supply signal according to a preset amplification factor to generate a first power supply voltage, and then transmit the first power supply voltage to the detection circuit. The detection circuit can generate a first detection voltage under the action of the first power supply voltage and the voltage of the shell, and feed it back to the above-mentioned control circuit. Furthermore, after receiving the first detection voltage, the control circuit combines the above-mentioned first power supply voltage, the first detection voltage and the resistance value of the resistance unit in the detection circuit to calculate the insulation resistance inside the battery module.

[0130] In some feasible embodiments, the control circuit can also generate and transmit a first power supply voltage and a second power supply voltage to the detection circuit respectively, and receive a first detection signal and a second detection signal respectively fed back by the detection circuit, and then calculate the insulation resistance inside the battery module, that is, the above-mentioned detection parameters, based on the first power supply voltage, the second power supply voltage, the first detection signal, the second detection signal and the resistance values ​​of the resistance units in the detection circuit, and then determine the insulation abnormality between the multiple battery cells inside the battery module and the outer casing of the battery module based on the detection parameters.

[0131] In some feasible embodiments, after the control circuit calculates the insulation resistance inside the battery module according to the above content, it can further determine the insulation abnormality between the multiple battery cells inside the battery module and the outer shell based on a preset resistance threshold and a comparison result of the insulation resistance.

[0132] In some feasible implementations, the battery module detection method provided in the embodiments of the present application further includes presetting voltage threshold intervals corresponding to each battery cell, and after calculating the insulation voltage within the battery module, determining a voltage threshold interval corresponding to the insulation voltage among the preset multiple voltage threshold intervals as a target voltage threshold interval. Furthermore, the control circuit can determine the battery cell corresponding to the target voltage threshold interval as a battery cell with an insulation abnormality, so that maintenance personnel can directly repair and replace the abnormally functioning battery cell in the battery module, thereby saving maintenance costs.

[0133] The specific implementation of the above S102 can refer to the implementation performed by the control circuit in Figures 3 to 5 above, and the embodiments of the present application will not be repeated here.

[0134] An embodiment of the present application also provides a non-volatile computer-readable storage medium, which stores a computer program. The computer program is executed by a processor to implement the operations performed by the control circuit in the above-mentioned method in Figure 6 and any of its possible method embodiments.

[0135] An embodiment of the present application further provides a computer program product. When the computer program product is read and executed by a computer, the operations performed by the control circuit in the aforementioned method in any of the above-mentioned Figure 6 and its possible method embodiments will be executed.

[0136] An embodiment of the present application also provides a power supply device, please refer to Figure 7, which is a structural diagram of the power supply device provided by the embodiment of the present application. In Figure 7, the power supply device includes a battery module, a battery management system and a battery module detection system in the above-mentioned various possible implementations. Among them, the battery module is electrically connected to the above-mentioned battery module detection system and the battery management system, respectively. The battery module detection system is used to detect insulation abnormalities inside the battery module and generate detection results based on the insulation abnormalities inside the battery module. The above-mentioned battery module detection system is connected to the battery management system and can send the above-mentioned detection results to the battery management system. Furthermore, the battery management system can output abnormal prompts or normal prompts based on the detection results.

[0137] In some feasible embodiments, the battery module includes at least two battery cells connected in series. For details, please refer to the specific implementation of the battery module shown in Figures 3 and 4, which will not be described in detail in this application.

[0138] It can be seen that the contents of the above-mentioned battery module detection system embodiment are applicable to the embodiment of this power supply device. The functions specifically implemented by this power supply device embodiment are the same as those of the above-mentioned battery module detection system embodiment, and the beneficial effects achieved are also the same as those achieved by the above-mentioned battery module detection system embodiment.

[0139] The embodiment of the present application further provides a battery information collector, as shown in FIG8 . The battery information collector includes the battery module detection system in the various possible implementations described above.

[0140] It can be seen that the contents of the above-mentioned battery module detection system embodiment are all applicable to the embodiment of this battery information collector. The functions specifically implemented by this battery information collector embodiment are the same as those of the above-mentioned battery module detection system embodiment, and the beneficial effects achieved are also the same as those achieved by the above-mentioned battery module detection system embodiment.

[0141] The present application also provides an electric device (see Figure 9), which includes the power supply device described in the various possible embodiments described above. For example, in some application scenarios, the electric device may be an electric vehicle, household appliance, terminal device, or other electrical device with a battery module, which is not limited in the present application.

[0142] It can be seen that the contents of the above power supply device embodiments are applicable to the embodiments of this electric device. The functions specifically implemented by this electric device embodiment are the same as those of the above power supply device embodiments, and the beneficial effects achieved are also the same as those achieved by the above power supply device embodiments.

[0143] It should be noted that for the aforementioned method embodiments, for the sake of simplicity, they are all expressed as a series of action combinations, but those skilled in the art should be aware that this application is not limited by the order of the actions described, because according to this application, certain steps may be performed in other orders or simultaneously. Secondly, those skilled in the art should also be aware that the embodiments described in this specification are all preferred embodiments, and the actions and modules involved are not necessarily required by this application.

[0144] In the embodiments provided in this application, it should be understood that the disclosed system can be implemented in other ways. For example, the system embodiments described above are merely illustrative. For example, the division of the modules described above 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, and the indirect coupling or communication connection of the system or unit can be electrical or other forms.

[0145] The modules described above as separate components may or may not be physically separate, and the components shown as modules may or may not be physical modules, that is, they may be located in one place or distributed across multiple network modules. Some or all of the modules may be selected according to actual needs to achieve the purpose of the present embodiment.

[0146] In addition, the functional modules in the embodiments of the present application may be integrated into a processing module, or each module may exist physically separately, or two or more modules may be integrated into a single module. The above-mentioned integrated modules may be implemented in the form of hardware or software functional modules.

[0147] The above is a detailed introduction to the embodiments of the present application. Specific examples are used herein to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the present application and its core ideas. At the same time, for those skilled in the art, based on the ideas of the present application, there may be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. A battery module detection system (300), characterized in that: The system (300) comprises a control circuit (301) and a detection circuit (302), wherein the detection circuit (302) is used to be electrically connected to a housing (330) of a battery module (320), the detection circuit (302) comprises a resistance unit, the control circuit (301) is connected to the detection circuit (302), and the control circuit (301) is used to: Controlling the transmission of the power supply voltage to the detection circuit (302), and obtaining the detection voltage fed back by the detection circuit (302); and The detection parameters inside the battery module (320) are determined based on the power supply voltage, the detection voltage and the resistance value of the resistance unit, and based on the detection parameters inside the battery module (320), it is determined whether there is an insulation abnormality inside the battery module (320).

2. The system (300) according to claim 1, characterized in that The power supply voltage includes a first power supply voltage, the detection voltage includes a first detection voltage fed back by the detection circuit (302); the detection parameter inside the battery module (320) includes the insulation resistance of the battery module (320); and The control circuit (301) is used to determine the insulation resistance of the battery module (320) based on the first power supply voltage, the first detection voltage, and the resistance value of the resistance unit, and to determine whether there is an insulation abnormality between a plurality of battery cells inside the battery module (320) and a housing (330) of the battery module (320) based on the insulation resistance of the battery module (320) and a preset resistance threshold.

3. The system (300) according to claim 1 or 2, characterized in that: The power supply voltage includes a first power supply voltage and a second power supply voltage, the detection voltage includes a first detection voltage and a second detection voltage, the first detection voltage is the detection voltage fed back by the detection circuit (302) when the power supply voltage is the first power supply voltage; the second detection voltage is the detection voltage fed back by the detection circuit (302) when the power supply voltage is the second power supply voltage; the detection parameters inside the battery module (320) include the insulation resistance of the battery module (320); and The control circuit (301) is used to determine the insulation resistance of the battery module (320) based on the first power supply voltage, the second power supply voltage, the first detection voltage, the second detection voltage, and the resistance value of the resistance unit, and to determine whether there is an insulation abnormality between a plurality of battery cells inside the battery module (320) and a housing (330) of the battery module (320) based on the insulation resistance of the battery module (320) and a preset resistance threshold.

4. The system (300) according to claim 3, characterized in that The detection parameters inside the battery module (320) also include the insulation voltage of the battery module (320); and The control circuit (301) is used to determine the insulation voltage of the battery module (320) according to the first power supply voltage, the second power supply voltage, the first detection voltage, the second detection voltage, and the resistance value of the resistance unit, and when the insulation resistance is less than the preset resistance threshold, determine a battery from a plurality of cells inside the battery module (320) according to the insulation voltage of the battery module (320). A battery cell with insulation anomalies.

5. The system (300) according to any one of claims 2 to 4, characterized in that: The control circuit (301) is used to determine the battery cell corresponding to the acquired target voltage threshold interval inside the battery module (320) as a battery cell with an insulation abnormality when the insulation resistance is less than the preset resistance threshold.

6. The system (300) according to any one of claims 1 to 5, characterized in that: The resistor unit includes a first resistor, a second resistor, a third resistor, a fourth resistor and a fifth resistor; One end of the first resistor is connected to a first port of the control circuit (301), the other end of the first resistor is respectively connected to one end of the second resistor, one end of the third resistor and one end of the fourth resistor, the other end of the second resistor is connected to a second port of the control circuit (301), the other end of the third resistor, the other end of the fourth resistor, the other end of the third resistor and one end of the fifth resistor are all grounded, and the other end of the fifth resistor is connected to a housing (330) of the battery module (320); and The control circuit (301) is used for transmitting the power supply voltage through the first port and obtaining the detection voltage through the second port.

7. The system (300) according to claim 6, characterized in that The power supply voltage includes a first power supply voltage, and the detection voltage includes a first detection voltage fed back by the detection circuit (302); the control circuit (301) is used to determine the insulation resistance of the battery module (320) according to the first power supply voltage, the first detection voltage, and the resistance value of the resistance unit, including: The control circuit (301) is used to calculate the insulation resistance inside the battery module (320) according to the following formula: Among them, R is the resistance value of the insulation resistor, U1 is the first detection voltage, V1 is the first power supply voltage, R1 is the resistance value of the first resistor, R2 is the resistance value of the second resistor, R3 is the resistance value of the third resistor, R4 is the resistance value of the fourth resistor, and R5 is the resistance value of the fifth resistor.

8. The system according to claim 6 or 7, characterized in that: The power supply voltage includes a first power supply voltage and a second power supply voltage, and the detection voltage includes a first detection voltage and a second detection voltage; the control circuit (301) is used to determine the insulation resistance of the battery module (320) according to the first power supply voltage, the second power supply voltage, the first detection voltage, the second detection voltage, and the resistance value of the resistance unit, including: The control circuit (301) is used to calculate the insulation resistance of the battery module (320) according to the following formula: Among them, R is the resistance value of the insulation resistor, U1 is the first detection voltage, U2 is the second detection voltage, V1 is the first power supply voltage, V2 is the second power supply voltage, R1 is the resistance value of the first resistor, R2 is the resistance value of the second resistor, R3 is the resistance value of the third resistor, R4 is the resistance value of the fourth resistor, and R5 is the resistance value of the fifth resistor.

9. The system (300) according to any one of claims 6 to 8, characterized in that: The power supply voltage includes a first power supply voltage and a second power supply voltage, and the detection voltage includes a first detection voltage and a second detection voltage; the control circuit (301) is used to calculate the insulation voltage of the battery module (320) according to the following formula: Among them, U x is the insulation voltage, U1 is the first detection voltage, U2 is the second detection voltage, V1 is the first power supply voltage, V2 is the second power supply voltage, R1 is the resistance value of the first resistor, R2 is the resistance value of the second resistor, R3 is the resistance value of the third resistor, R4 is the resistance value of the fourth resistor, and R5 is the resistance value of the fifth resistor.

10. The system (300) according to any one of claims 6 to 9, characterized in that: The detection circuit (302) further includes a first capacitor (C1) and a second capacitor (C2); and The first capacitor (C1) is connected in parallel with the third resistor, one end of the second capacitor (C2) is connected to the other end of the fourth resistor, and the other end of the second capacitor (C2) is grounded.

11. The system (300) according to any one of claims 6 to 10, characterized in that: The detection circuit (302) further includes a first diode (D1) and a second diode (D2); and The anode of the first diode (D1) is connected to the first port of the control circuit (301), and the cathode of the first diode (D1) is connected to one end of the second resistor; the cathode of the second diode (D2) is connected to the second port of the control circuit (301), and the anode of the second diode (D2) is grounded.

12. A battery module detection method, characterized in that: The method is performed by a battery module detection system, the battery module detection system includes a control circuit and a detection circuit connected to the control circuit, the detection circuit is electrically connected to a housing of the battery module and includes a resistance unit, and the method includes: The control circuit controls (S101) to transmit the power supply voltage to the detection circuit, and obtains the detection voltage fed back by the detection circuit; and The control circuit determines detection parameters inside the battery module according to the power supply voltage, the detection voltage and the resistance value of the resistance unit, and determines (S102) whether there is an insulation abnormality inside the battery module according to the detection parameters inside the battery module.

13. The method according to claim 12, characterized in that The power supply voltage includes a first power supply voltage, the detection voltage includes a first detection voltage fed back by the detection circuit; the detection parameter inside the battery module includes the insulation resistance of the battery module; The determining, according to the power supply voltage, the detection voltage, and the resistance value of the resistance unit, the detection parameters inside the battery module, and determining, according to the detection parameters inside the battery module, whether there is an insulation abnormality inside the battery module, includes: The insulation resistance of the battery module is determined based on the first power supply voltage, the first detection voltage, and the resistance value of the resistance unit, and based on the insulation resistance of the battery module and a preset resistance threshold, it is determined whether there is an insulation abnormality between the multiple battery cells inside the battery module and the outer casing of the battery module.

14. The method according to claim 13, characterized in that The power supply voltage includes a first power supply voltage and a second power supply voltage, the detection voltage includes a first detection voltage and a second detection voltage, the first detection voltage is the detection voltage fed back by the detection circuit when the power supply voltage is the first power supply voltage; the second detection voltage is the detection voltage fed back by the detection circuit when the power supply voltage is the second power supply voltage; the detection parameters inside the battery module include the insulation resistance of the battery module; The determining, according to the power supply voltage, the detection voltage, and the resistance value of the resistance unit, the detection parameters inside the battery module, and determining, according to the detection parameters inside the battery module, whether there is an insulation abnormality inside the battery module, includes: The insulation resistance of the battery module is determined based on the first power supply voltage, the second power supply voltage, the first detection voltage, the second detection voltage, and the resistance value of the resistance unit, and based on the insulation resistance of the battery module and a preset resistance threshold, it is determined whether there is an insulation abnormality between the multiple battery cells inside the battery module and the outer casing of the battery module.

15. The method according to claim 13 or 14, characterized in that The power supply voltage includes a first power supply voltage and a second power supply voltage, the detection voltage includes a first detection voltage and a second detection voltage, and the detection parameters inside the battery module also include an insulation voltage of the battery module; The determining, according to the power supply voltage, the detection voltage, and the resistance value of the resistance unit, the detection parameters inside the battery module, and determining, according to the detection parameters inside the battery module, whether there is an insulation abnormality inside the battery module, includes: The control circuit is used to determine the insulation voltage of the battery module based on the first power supply voltage, the second power supply voltage, the first detection voltage, the second detection voltage, and the resistance value of the resistance unit. When the insulation resistance is less than the preset resistance threshold, the control circuit is used to determine the battery cell with insulation abnormality from the multiple battery cells inside the battery module based on the insulation voltage of the battery module.

16. The method according to any one of claims 13 to 15, characterized in that When the insulation resistance is less than the preset resistance threshold, determining a battery cell with insulation abnormality from a plurality of battery cells inside the battery module according to the insulation voltage of the battery module, comprises: When the insulation resistance is less than the preset resistance threshold, the battery cell inside the battery module corresponding to the acquired target voltage threshold interval is determined as a battery cell with insulation abnormality.

17. A non-volatile computer-readable storage medium, characterized in that: The non-volatile computer-readable storage medium stores a computer program, and the computer program is suitable for being loaded and executed by a processor, so that a computer device having the processor executes the method according to any one of claims 12 to 16.

18. A computer program product, characterized in that When the computer program product is executed by a processor, the method according to any one of claims 12 to 16 will be implemented.

19. A battery information collector, characterized in that: The battery information collector comprises the battery module detection system (300) according to any one of claims 1 to 11.

20. A power supply device, characterized in that: It comprises a battery module, a battery management system and a battery module detection system (300) as claimed in any one of claims 1 to 11 or a battery information collector as claimed in claim 19; The battery module detection system is used to detect the insulation abnormality inside the battery module, generate a detection result according to the insulation abnormality inside the battery module, and send the detection result to the battery management system; The battery management system is used to output an abnormal prompt or a normal prompt according to the detection result.

21. The power supply device according to claim 20, characterized in that: The battery module includes at least two battery cells connected in series.

22. An electric device, comprising the power supply device according to claim 20 or claim 21.

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