Battery Module Detection System and Its Method

Abstract

The present application provides a battery module detection system and method, including a control circuit and a detection circuit. The detection circuit is electrically connected to the outer shell of the battery module, and the control circuit is connected to the detection circuit. The control circuit is used to control the power supply voltage to be transmitted to the detection circuit and obtain the detection voltage fed back by the detection circuit. The detection circuit includes a resistance unit. The control circuit is used to determine the 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. The battery module detection system of the present application can detect the insulation abnormality inside the battery module and ensure the safety and stability of the battery module.

Description

Technical Field

[0001] This application relates to the field of power electronics technology, and particularly to a battery module detection system and method thereof. Background Art

[0002] A power battery pack is composed of one or more battery modules, and each battery module includes multiple battery cells. Generally, the outer shell of the power battery pack is insulated from the battery modules inside the power battery pack, and the outer shell of each battery module is insulated from the multiple battery cells inside the battery module.

[0003] 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 circuit. When the insulation resistance between the outer shell of the battery module and the internal battery cells decreases, furthermore, the insulation performance between the outer shell of the battery module and the internal battery cells deteriorates, which will pose a safety hazard to the power battery pack and even the vehicle. Summary of the Invention

[0004] This 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.

[0005] In a first aspect, this application provides a battery module detection system. The system includes a control circuit and a detection circuit. The detection circuit is electrically connected to the outer shell of the battery module, and the control circuit is connected to the detection circuit. The control circuit is used to control the power supply voltage to be transmitted to the detection circuit and obtain the detection voltage fed back by the detection circuit. The detection circuit includes a resistance unit. The control circuit is used to determine the 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.

[0006] In a possible implementation manner, the power supply voltage includes a first power supply voltage, and the detection voltage includes the first detection voltage fed back by the detection circuit when the power supply voltage is the first power supply voltage. The detection parameters inside the battery module include insulation resistance. The control circuit is used to determine the insulation resistance inside the battery module according to the first power supply voltage, the first detection voltage, and the resistance value of the resistance unit, and determine whether there is an insulation abnormality between the multiple battery cells inside the battery module and the outer shell of the battery module according to the insulation resistance inside the battery module and a preset resistance threshold.

[0007] In a possible implementation, the above power supply voltage includes a first power supply voltage and a second power supply voltage, the above detection voltage includes a first detection voltage and a second detection voltage, the above first detection voltage is the detection voltage fed back by the above detection circuit when the above power supply voltage is the above first power supply voltage; the above second detection voltage is the detection voltage fed back by the above detection circuit when the above power supply voltage is the above second power supply voltage; the detection parameters inside the above battery module include insulation resistance; the above control circuit is used to determine the insulation resistance inside the above battery module according to the above first power supply voltage, the above second power supply voltage, the above first detection voltage, the above second detection voltage, and the resistance value of the above resistance unit, and determine whether there is an insulation abnormality between the multiple battery cells inside the above battery module and the outer shell of the above battery module according to the insulation resistance inside the above battery module and a preset resistance threshold.

[0008] In a possible implementation, the detection parameters inside the above battery module further include insulation voltage; the above control circuit is used to determine the insulation voltage inside the above battery module according to the above first power supply voltage, the above second power supply voltage, the above first detection voltage, the above second detection voltage, and the resistance value of the above resistance unit, and when the above insulation resistance is less than the above preset resistance threshold, determine the battery cells with insulation abnormality from the multiple battery cells inside the above battery module according to the insulation voltage inside the above battery module.

[0009] In a possible implementation, the above control circuit is used to, when the above insulation resistance is less than the above preset resistance threshold, determine the battery cells corresponding to the obtained target voltage threshold range inside the above battery module as the battery cells with insulation abnormality.

[0010] In a possible implementation, the above resistance unit includes a first resistor, a second resistor, a third resistor, a fourth resistor, and a fifth resistor; one end of the above first resistor is connected to the first port of the above control circuit, the other end of the above first resistor is respectively connected to one end of the above second resistor, one end of the above third resistor, and one end of the above fourth resistor, the other end of the above second resistor is connected to the second port of the above control circuit, the other ends of the above third resistor, the above fourth resistor, and the other end of the above third resistor and one end of the above fifth resistor are all grounded, and the other end of the above fifth resistor is connected to the outer shell of the above battery module; the above control circuit is used to transmit the above power supply voltage through the above first port, and the above control circuit is used to obtain the above detection voltage through the above second port.

[0011] In a possible implementation, the above control circuit is used to determine the insulation resistance inside the above battery module according to the above first power supply voltage, the above first detection voltage, and the resistance value of the above resistance unit, including:

[0012] The above control circuit calculates the insulation resistance inside the above battery module according to the following formula:

[0013]

[0014] Wherein, R is the resistance value of the above insulation resistance, U 1 is the above first detection voltage, V 1 is the above first power supply voltage, R 1 is the resistance value of the above first resistor, R 2 is the resistance value of the above second resistor, R 3 is the resistance value of the above third resistor, R 4 is the resistance value of the above fourth resistor, R 5 is the resistance value of the above fifth resistor.

[0015] In a possible implementation manner, the above control circuit is used to determine the insulation resistance inside the above battery module according to the above first power supply voltage, the above second power supply voltage, the above first detection voltage, the above second detection voltage, and the resistance values of the above resistance unit, including:

[0016] The above control circuit calculates the insulation resistance inside the above battery module according to the following formula:

[0017]

[0018] Wherein, R is the resistance value of the above insulation resistance, U 1 is the above first detection voltage, U 2 is the above second detection voltage, V 1 is the above first power supply voltage, V 2 is the above second power supply voltage, R 1 is the resistance value of the above first resistor, R 2 is the resistance value of the above second resistor, R 3 is the resistance value of the above third resistor, R 4 is the resistance value of the above fourth resistor, R 5 is the resistance value of the above fifth resistor.

[0019] In a possible implementation manner, the above control circuit calculates the insulation voltage inside the above battery module according to the following formula:

[0020]

[0021] Wherein, U x is the above insulation voltage, U 1 is the above first detection voltage, U 2 is the above second detection voltage, V 1 is the above first power supply voltage, V2 is the second power supply voltage above, R 1 is the resistance value of the first resistor above, R 2 is the resistance value of the second resistor above, R 3 is the resistance value of the third resistor above, R 4 is the resistance value of the fourth resistor above, R 5 is the resistance value of the fifth resistor above.

[0022] In a possible implementation manner, the above detection circuit further includes a first capacitor and a second capacitor; the first capacitor is connected in parallel with 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.

[0023] In a possible implementation manner, the above 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.

[0024] In a second aspect, the present application further provides a battery module detection method, which is applied to a control circuit in a battery module detection system. The battery module detection system further includes a detection circuit, and the detection circuit is electrically connected to the housing of the battery module. The control circuit is connected to the detection circuit. The method includes:

[0025] Controlling the power supply voltage to be transmitted to the above detection circuit and obtaining the detection voltage fed back by the above detection circuit; the detection circuit includes a resistor unit;

[0026] Determining the detection parameters inside the battery module according to the above power supply voltage, the above detection voltage, and the resistance value of the resistor unit, and determining whether there is an insulation abnormality inside the battery module according to the detection parameters inside the battery module.

[0027] In a possible implementation manner, the above power supply voltage includes a first power supply voltage, and the above detection voltage includes a first detection voltage fed back by the above detection circuit when the above power supply voltage is the first power supply voltage; the detection parameters inside the battery module include insulation resistance;

[0028] Determining the detection parameters inside the battery module according to the above power supply voltage, the above detection voltage, and the resistance value of the resistor unit, and determining whether there is an insulation abnormality inside the battery module according to the detection parameters inside the battery module, includes:

[0029] 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, the insulation resistance inside the above-mentioned battery module is determined, and based on the insulation resistance inside the above-mentioned battery module and a preset resistance threshold, it is determined whether there is an insulation abnormality between the multiple battery cells inside the above-mentioned battery module and the outer shell of the above-mentioned battery module.

[0030] In a possible implementation manner, the above-mentioned power supply voltage includes a first power supply voltage and a second power supply voltage, the above-mentioned detection voltage includes a first detection voltage and a second detection voltage, the above-mentioned first detection voltage is the detection voltage fed back by the above-mentioned detection circuit when the above-mentioned power supply voltage is the above-mentioned first power supply voltage; the above-mentioned second detection voltage is the detection voltage fed back by the above-mentioned detection circuit when the above-mentioned power supply voltage is the above-mentioned second power supply voltage; the detection parameters inside the above-mentioned battery module include insulation resistance;

[0031] Based on the above-mentioned power supply voltage, the above-mentioned detection voltage, and the resistance value of the above-mentioned resistance unit, the detection parameters inside the above-mentioned battery module are determined, and based on the detection parameters inside the above-mentioned battery module, it is determined whether there is an insulation abnormality inside the above-mentioned battery module, including:

[0032] 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, the insulation resistance inside the above-mentioned battery module is determined, and based on the insulation resistance inside the above-mentioned battery module and a preset resistance threshold, it is determined whether there is an insulation abnormality between the multiple battery cells inside the above-mentioned battery module and the outer shell of the above-mentioned battery module.

[0033] In a possible implementation manner, the detection parameters inside the above-mentioned battery module further include insulation voltage;

[0034] Based on the above-mentioned power supply voltage, the above-mentioned detection voltage, and the resistance value of the above-mentioned resistance unit, the detection parameters inside the above-mentioned battery module are determined, and based on the detection parameters inside the above-mentioned battery module, it is determined whether there is an insulation abnormality inside the above-mentioned battery module, including:

[0035] The above-mentioned control circuit is used to determine the insulation voltage inside 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, based on the insulation voltage inside the above-mentioned battery module, the battery cells with insulation abnormalities are determined from the multiple battery cells inside the above-mentioned battery module.

[0036] In a possible implementation, when the insulation resistance is less than the preset resistance threshold, determining the battery cells with insulation anomalies from multiple battery cells inside the battery module according to the insulation voltage inside the battery module includes:

[0037] When the insulation resistance is less than the preset resistance threshold, determining the battery cells corresponding to the obtained target voltage threshold range inside the battery module as the battery cells with insulation anomalies.

[0038] In a third aspect, the present application further provides a computer-readable storage medium storing a computer program or computer instructions, and the aforementioned computer program or computer instructions are executed by a processor to implement the method according to any one of the foregoing in the second aspect.

[0039] In a fourth aspect, the present application further provides a computer program product, and when the computer program product is executed by a processor, the method according to any one of the foregoing in the second aspect will be executed.

[0040] In a fifth aspect, the present application further provides a battery information collector, and the battery information collector includes the battery module detection system according to the first aspect.

[0041] In a sixth aspect, the present application further provides a power supply device including a battery module, a battery management system, and the battery module detection system according to the first aspect or the battery information collector according to the second aspect; the battery module detection system is configured to detect insulation anomalies inside the battery module, generate a detection result according to the insulation anomalies inside the battery module, and send the detection result to the battery management system; the battery management system is configured to output an anomaly prompt or a normal prompt according to the detection result.

[0042] In a possible implementation, the battery module includes at least two battery cells connected in series.

[0043] In a seventh aspect, the present application further provides an electric device, and the electric device includes the power supply device according to the third aspect.

[0044] In the embodiments of the present application, the battery module detection system can detect the insulation abnormality inside the battery module, be able to locate the battery module with insulation abnormality, and is beneficial to giving an early warning in time when there is an insulation abnormality inside the battery module, ensuring the safety and effectiveness of the battery module, power battery pack, and vehicle. Among them, the battery module detection system includes a control circuit and a detection circuit, and the detection circuit is respectively connected to the control circuit and the battery module to be detected. Further, the above control circuit can generate and transmit a power supply voltage to the detection circuit, and the above detection circuit includes a resistance unit. The detection circuit generates a detection voltage based on the resistance unit, the power supply voltage, and the battery module; the detection circuit can feedback the generated detection voltage to the control circuit. The control circuit calculates the detection parameters inside the battery module according to the received detection voltage, the generated power supply voltage, and the resistance value of the above resistance unit. It can be understood that the detection parameter can be understood as a parameter used to characterize the insulation abnormality between 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 according to the above detection parameters, which is beneficial to giving an early warning in time when there is an insulation abnormality inside the battery module, and then can facilitate the maintenance personnel to check the abnormality of the battery module, ensuring the safety and effectiveness of the battery module, power battery pack, and vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for the embodiments. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained according to these drawings without creative efforts.

[0046] Figure 1 FIG. 1 is a schematic structural diagram of a power battery pack provided by an embodiment of the present application;

[0047] Figure 2 FIG. 2 is another schematic structural diagram of a power battery pack provided by an embodiment of the present application;

[0048] Figure 3 FIG. 3 is a schematic structural diagram of a battery module detection system provided by an embodiment of the present application;

[0049] Figure 4 FIG. 4 is a schematic structural diagram of a detection circuit provided by an embodiment of the present application;

[0050] Figure 5 FIG. 5 is another schematic structural diagram of a detection circuit provided by an embodiment of the present application;

[0051] Figure 6 FIG. 6 is a schematic flowchart of a battery module detection method provided by the present application;

[0052] Figure 7 It is a schematic structural diagram of a power supply device provided by an embodiment of the present application. Specific Embodiments

[0053] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0054] The following will be described in detail respectively.

[0055] The terms "first", "second", "third", "fourth", etc. in the specification and claims of the present application and the accompanying drawings are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the listed steps or units, but optionally further includes steps or units not listed, or optionally further includes other steps or units inherent to these processes, methods, products, or devices.

[0056] Referring to "embodiment" herein means that a specific feature, structure, or characteristic described in conjunction with the embodiment may be included in at least one embodiment of the present application. The phrase appears in various positions in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art explicitly and implicitly understand that the embodiments described herein can be combined with other embodiments.

[0057] It should be noted that the power battery pack is the power source of a new energy vehicle, used to store electric energy and provide electric energy to the new energy vehicle. Generally, the output voltage of the power battery pack exceeds 300 volts. Therefore, multiple battery cells can be connected in series or in parallel to form a battery module, and then multiple battery modules are connected in series or in parallel to form a power battery pack to increase the output voltage of the power battery pack.

[0058] Exemplarily, the above battery module may be a battery module composed of multiple battery cells. Or, the above battery module may also be a battery pack formed by encapsulating multiple battery cells. Or, the above battery module may also be directly encapsulated in the chassis by multiple battery cells. It can be understood that this is only an example here and does not constitute a limitation to the embodiments of the present application.

[0059] In some feasible embodiments, please refer to Figure 1 ,Figure 1 This is a schematic structural diagram of the power battery pack provided by the embodiment of the present application. As Figure 1 shown, the power battery pack 100 includes a housing 110 and a plurality of battery modules. The housing 110 serves as a protective structure for the power battery pack 100 and can play a role in fixing and supporting the plurality of battery modules therein. The above-mentioned plurality of battery modules include a battery module 120 and a battery module 130, and the plurality of battery modules are connected in series through BC poles. The above-mentioned BC poles can be understood as connection terminals for the battery modules to connect to external conductors. For example, the BC pole of the battery module 130 is connected to the BC pole of the battery module 120, so that the battery module 130 is electrically connected to the battery module 120. Further, Figure 1 each battery module includes a housing and a plurality of battery cells BT1, BT2, BT3,... The plurality of battery cells are connected in series. The housing of the above-mentioned battery module is used to encapsulate and protect the plurality of battery cells in the battery module, thereby avoiding 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 plurality of battery cells connected in series in the battery module. Similarly, the voltage of the power battery pack 100 is equal to the sum of the voltages of the plurality of battery modules connected in series in the power battery pack 100.

[0060] In some feasible embodiments, the housing 110 of the power battery pack 100 is insulated from the plurality of battery modules, which can avoid interference from the outside to the plurality of battery modules inside the power battery pack 100. For example, in the case of a humid and high-temperature external environment, the housing 110 can keep the plurality of battery modules safe and effective by being insulated from the plurality of battery modules. Similarly, the housing of each of the above-mentioned battery modules is insulated from the plurality of battery cells inside the battery module, which can avoid adverse effects from the outside on the plurality of battery cells inside and avoid interference between different battery modules. For example, assume Figure 1 that when a fault occurs in the battery cells of the battery module 120, since the battery module 120 is insulated from the battery module 130 through its housing 140, and the battery module 130 is insulated from the battery module 120 through its housing 150, the fault of the battery module 120 will not affect the normal operation of the battery module 130.

[0061] 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 outer shell of the power battery pack and the battery module will decrease, thereby affecting the safety and stability of the power battery pack. Among them, the insulation performance between the outer shell of the power battery pack and the battery module can be understood as the resistance value of the equivalent insulation resistance between the outer shell of the power battery pack and the battery module. Further, the equivalent insulation resistance between the outer shell of the power battery pack and the battery module refers to the ratio of the voltage applied between the outer shell of the power battery pack and the battery module to the current flowing from the outer shell to the battery module or from the battery module to the outer shell. When there is complete insulation between the outer shell and the battery module, the resistance value of the above-mentioned equivalent insulation resistance is infinite. When the insulation performance between the battery and the battery module decreases, 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.

[0062] 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.

[0063] In some feasible embodiments, when the battery cells of one or more battery modules leak liquid and the liquid penetrates outside the battery module, the leaked liquid will cause the insulation between the outer shell of the power battery pack and the battery module to no longer exist, that is, the insulation performance decreases. To ensure the safety and stability of the power battery pack, the equivalent insulation resistance between the outer shell of the power battery pack and the battery module can be detected.

[0064] In some feasible embodiments, the equivalent insulation resistance between the outer shell of the above-mentioned power battery pack and multiple battery modules can be characterized by the resistance value between the bus bar of the power battery pack and the outer shell. Among them, the bus bar of the power battery pack can be understood as the main bus for power supply or charging of the power battery pack. For ease of understanding, the embodiments of the present application are described by taking the Figure 2 power battery pack 200 as an example.

[0065] Please refer to Figure 2 , Figure 2 which is another structural schematic diagram of the power battery pack provided by the embodiments of the present application. As Figure 2As shown, the total negative bus of the power battery pack 200 is connected to the BC pole column of the battery module 220, which is equivalent to the negative pole of the power battery pack 200; the total positive bus of the power battery pack 200 is connected to the BC pole column 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 resistors Ra, Rb, Rc, and Rd connected in series. The equivalent insulation resistance between the housing 210 of the power battery pack 200 and multiple battery modules can be characterized by the resistance Rp between the total positive bus of the power battery pack 200 and the housing 210, and the resistance Rn between the total negative bus and the housing 210. For this reason, the power battery pack 200 can detect the above resistances Rp and Rn through the insulation detection circuit 240 to determine the equivalent insulation resistance between the housing 210 and the battery module 220 or the battery module 230, and then can give an early warning in time when there is an insulation abnormality in one or more battery modules in the power battery pack 200.

[0066] However, with the continuous upgrade and iteration of the packaging technology of battery modules, when a battery cell inside a battery module fails, it usually does not affect the outside of the battery module. For example, when a battery cell inside a battery module leaks, the leaked liquid usually only stays inside the battery module, resulting in a decrease in the insulation performance inside the battery module, but will not penetrate to the outside of the battery module and does not affect the insulation performance between the housing of the power battery pack and the battery module. It can be understood that Figure 2 the insulation detection circuit 240 shown can only be used to detect the equivalent insulation resistance between the housing 210 of the power battery pack 200 and multiple battery modules, but cannot detect the insulation performance inside any battery module. Therefore, when an abnormality occurs in the battery cell inside the battery, resulting in a decrease in the insulation performance inside the battery module, an early warning cannot be given in time, posing a safety hazard.

[0067] Based on the above technical problems, the embodiments of the present application provide a battery module detection system, which can detect the insulation performance inside the battery module to give an early warning in time when the equivalent insulation resistance between the housing and the battery cell of the battery module decreases due to an insulation abnormality in the battery cell of the battery module, thereby improving the safety and stability of the power battery pack.

[0068] In some feasible embodiments, please refer to Figure 3 , Figure 3 which is a schematic structural diagram of the battery module detection system provided by the embodiments of the present application. Figure 3The battery module detection system 300 shown is disposed within the power battery pack 310 and is used to detect insulation anomalies inside the battery module 320 in the power battery pack 310. The battery module 320 internally includes multiple battery cells such as battery cell BT1, battery cell BT2, battery cell BT3, and so on. Further, the insulation anomaly inside the battery module 320 can be understood as a situation where one or more of the multiple battery cells inside the battery module 320 malfunction, resulting in the battery module 320 being unable to operate properly. For example, when the battery cell BT1 leaks liquid, the equivalent insulation resistance between the battery cell BT1 and the housing 330 of the battery module 320 decreases, that is, the battery cell BT1 malfunctions. Or, when the battery cell BT2 arcs, the equivalent insulation resistance between the battery cell BT2 and the above-mentioned housing 330 also decreases, that is, the battery cell BT2 malfunctions. Or, when the battery cell BT3 experiences a micro short circuit, the equivalent insulation resistance between the battery cell BT3 and the above-mentioned housing 330 also decreases, that is, the battery cell BT2 malfunctions. Any abnormal condition of any battery cell in the above battery module 320 will cause the battery module 320 to be unable to operate properly, that is, an insulation anomaly occurs inside the battery module 320. It should be noted that the above insulation anomaly conditions such as battery cell leakage, arcing, and micro short circuit are only examples, and other insulation anomaly conditions may also occur in the battery module 320, which will not be elaborated one by one in this application.

[0069] In some feasible embodiments, the battery module detection system 300 of the embodiments of the present application can obtain the detection parameters inside the battery module 320 by detecting the battery module 320. The detection parameters inside the battery module 320 can be understood as parameters used to characterize whether there are abnormal operations of the battery cells inside the battery module 320. Then, the battery module detection system 300 can determine whether there are abnormal operations of the battery cells inside the battery module 320 based on the detection parameters, and further determine the insulation anomaly inside the battery module 320.

[0070] That is to say, the battery module detection system 300 can first obtain the detection parameters inside the battery module 320, and then determine the insulation anomaly inside the battery module 320 based on the detection parameters. For ease of understanding, the embodiments of the present application will explain the specific process of obtaining the detection parameters inside the battery module 320 in the following content.

[0071] 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 battery cells inside the battery module 320 are insulated from the outer casing 330, so the voltage inside the battery module 320 is distributed among the multiple series-connected battery cells, and at the same time, the outer casing 330 is not charged, that is, the voltage of the outer casing 330 is 0. When the battery cell BT1 inside the battery module 320 leaks liquid, the battery cell BT1 is electrically connected to the above-mentioned outer casing 330 through the leaked liquid, so the voltage inside the battery module 320 is distributed among the outer casing 330 and the multiple series-connected battery cells. At this time, the outer casing 330 is charged and the voltage of the outer casing 330 is no longer 0. That is to say, 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 according to the embodiments of the present application can detect the voltage change inside the battery module 320 and use the voltage change inside the battery module 320 as the above-mentioned detection parameter.

[0072] In some feasible embodiments, the battery module detection system 300 includes a control circuit 301 and a detection circuit 302. The detection circuit 302 is respectively connected to the battery module 320 and the control circuit 301. As can be seen from the above content, when the voltage distribution inside the battery module 320 changes, the voltage of the outer casing 330 of the battery module 320 also changes, that is, the voltage change of the outer casing 330 can reflect the voltage change inside the battery module 320. Therefore, the battery module detection system 300 can connect to the outer casing 330 of the battery module 320 through the detection circuit 302 to obtain a detection parameter when an insulation abnormality occurs inside the battery module 320, resulting in a voltage change of the outer casing 330, and then determine the insulation abnormality inside the battery module 320 according to the detection parameter.

[0073] In some feasible embodiments, while detecting the voltage inside the battery module 320, the detection circuit 302 can also receive the power supply voltage generated by the control circuit 301. Further, when the voltage inside the battery module 320 changes, causing the voltage of the outer casing 330 to also change, the detection circuit 302 can generate a corresponding detection voltage under the action of the voltage of the outer casing 330 and the power supply voltage. It should be noted that the detection circuit 302 includes a resistance unit, and the resistance unit can generate different detection voltages under the action of different voltages of the outer casing 330 and the power supply voltage. Therefore, the detection circuit 302 can feedback the detection voltage to the control circuit 301, so that the control circuit 301 can inversely calculate the internal voltage of the battery module 320 according to the generated power supply voltage, the received detection voltage, and the resistance value of the resistance unit in the detection circuit 302, and then determine the insulation abnormality inside the battery module 320.

[0074] In some feasible embodiments, the above control circuit 301 can receive a power supply signal and operate based on this power supply signal. This power supply signal can be understood as the DC operating voltage of the control circuit 301. For example, assuming the DC operating voltage of the control circuit 301 is 3.3 volts, then the control circuit 301 can receive a 3.3 - volt DC voltage as the above - mentioned power supply signal. It can be understood that this power supply signal can be provided to the control circuit 301 by an external DC power supply, and this application does not limit this. Further, the control circuit 301 can generate a power supply voltage according to this power supply signal. Specifically, the control circuit 301 can amplify the above - mentioned power supply signal according to a preset amplification factor, and then generate the above - mentioned power supply voltage. This amplification factor can be an integer or a fraction greater than 0. For example, when the power supply signal of the control circuit 301 is 3.3 volts and 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 this amplification factor to generate a 3.3 - volt power supply voltage. Similarly, when the power supply voltage is other values, the preset amplification factor can be changed to generate a corresponding power supply voltage. And this power supply voltage is transmitted to the detection circuit 302, so that the detection circuit 302 can generate a corresponding detection voltage under the action of this power supply voltage and the voltage of the housing 330, and feedback it to the control circuit 301.

[0075] In some feasible embodiments, from the above content, it can be known that the insulation performance between the housing 330 of the battery module 320 and 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 multiple internal battery cells of the battery module 320 and the housing 330. For example, when there is no abnormal operation of the battery cells in the battery module 320, all the battery cells in the battery module 320 are insulated from the housing 330, and the equivalent resistance between multiple battery cells and the housing 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 has an abnormal operation, the equivalent resistance between the battery cell BT1 and the housing 330 decreases, and then the insulation resistance inside the battery module 320 decreases. Therefore, in the battery module detection system 300 of this application embodiment, the insulation resistance between the housing 330 and the internal battery cells can be detected to determine the insulation abnormal situation between multiple battery cells and the housing 330 in the battery module 320.

[0076] In some feasible embodiments, when the above 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 a first detection voltage under the action of the first power supply voltage and the voltage of the housing 330, and feedback it to the above control circuit 301. Further, after receiving the first detection voltage, the control circuit 301 calculates the insulation resistance inside the battery module 320 by combining the first power supply voltage, the first detection voltage, and the resistance value of the resistance unit in the detection circuit 302.

[0077] In some feasible embodiments, for the convenience of understanding the principle of the control circuit calculating the insulation resistance according to the above method, the embodiments of the present application will be described in detail in combination with Figure 4 for detailed description.

[0078] Specifically, please refer to Figure 4 which Figure 4 is a schematic structural diagram of the detection circuit provided by the embodiments of the present application. As Figure 4 shown, the resistance unit of the detection circuit 400 includes a first resistor R 1 , a second resistor R 2 , a third resistor R 3 , a fourth resistor R 4 , and a fifth resistor R 5 . Among them, one end of the first resistor R 1 is connected to the first port a1 of the control circuit 410, and the other end of the first resistor R 1 is respectively connected to one end of the second resistor R 2 , one end of the third resistor R 3 , and one end of the fourth resistor R 4 . The other end of the second resistor R 2 is connected to the second port a2 of the control circuit 410. The other end of the third resistor R 3 is grounded. The other end of the fourth resistor R 4 is respectively connected to the other end of the third resistor R 3 and one end of the fifth resistor R 5 . The other end of the fifth resistor R 5 is connected to the housing 430 of the battery module 420.

[0079] It can be understood that after the above control circuit 410 generates the first power supply voltage, it 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. From the above content, it can be known that the first detection voltage is related to the above first power supply voltage, the voltage inside the battery module 420, and the resistance values of the above respective resistors. Further, 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.

[0080] In some feasible embodiments, the first detection voltage U 1 can be characterized by the following formula (1):

[0081]

[0082] wherein, R is the resistance value of the insulation resistance inside the battery module 420, U 1 is the first detection voltage, V 1 is the first power supply voltage, R 1 is the resistance value of the first resistor, R 2 is the resistance value of the second resistor, R 3 is the resistance value of the third resistor, R 4 is the resistance value of the fourth resistor, R 5 is the resistance value of the fifth resistor.

[0083] In some feasible embodiments, the above control circuit 410 can, according to the following formula (2), and after receiving the first detection voltage U feedback by the detection circuit 400 1 calculate the insulation resistance R inside the battery module 420 according to the following formula (2):

[0084]

[0085] wherein, R is the resistance value of the insulation resistance inside the battery module 420, U 1 is the first detection voltage, V 1 is the first power supply voltage, R 1 is the resistance value of the first resistor, R 2 is the resistance value of the second resistor, R 3 is the resistance value of the third resistor, R 4 is the resistance value of the fourth resistor, R 5 is the resistance value of the fifth resistor.

[0086] Generally speaking, the control circuit 410 can generate and transmit a first power supply voltage to the detection circuit 400, receive the first detection signal fed back by the detection circuit 400, and then calculate the insulation resistance inside the battery module 420, i.e., the above-mentioned detection parameter, based on the first power supply voltage, the first detection signal, and the respective resistance values of the resistance units in the detection circuit 400. Furthermore, based on this detection parameter, it can determine the insulation abnormality between the multiple battery cells inside the battery module 420 and the housing 430 of the battery module 420.

[0087] In some feasible embodiments, Figure 4 As shown, in addition to calculating the insulation resistance inside the battery module 420 according to the above formula (2), the control circuit 410 can also calculate the above-mentioned insulation resistance according to the following method. At this time, the control circuit 410 can generate a first power supply voltage and a second power supply voltage according to a preset amplification 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 housing 430, and feed it back to the above-mentioned 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 housing 430, and feed it back to the above-mentioned control circuit 410. Further, after receiving the first detection voltage and the second detection voltage, the control circuit 410 calculates the insulation resistance inside the battery module 420 in combination with the above-mentioned first power supply voltage, second power supply voltage, first detection voltage, second detection voltage, and the resistance value of the resistance unit in the detection circuit 400.

[0088] In some feasible embodiments, for the convenience of understanding the principle of the control circuit 410 calculating the insulation resistance according to the above method, the embodiments of the present application are combined with Figure 4 for detailed description.

[0089] Specifically, please refer to Figure 4 again. Figure 4The shown control circuit 410 can transmit the first power supply voltage to the detection circuit 400 through the first port a1 after generating the first power supply voltage. 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. From the above, it can be known that the first detection voltage is related to the above first power supply voltage, the voltage inside the battery module 420, and the resistance values of the above respective resistors. Further, 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. From the above, it can be known that the second detection voltage is related to the above second power supply voltage, the voltage inside the battery module 420, and the resistance values of the above respective resistors. Further, the detection circuit 400 can feedback the second detection voltage through the second port a2 of the control circuit 410.

[0090] It should be noted that in some feasible embodiments, the first detection voltage feedback by the detection circuit 400 can be characterized by the above formula (3):

[0091]

[0092] where U 1 is the first detection voltage, V 1 is the first power supply voltage, R 1 is the resistance value of the first resistor, R 2 is the resistance value of the second resistor, R 3 is the resistance value of the third resistor, R 4 is the resistance value of the fourth resistor, R 5 is the resistance value of the fifth resistor, U x is the voltage inside the battery module 420.

[0093] Similarly, the second detection voltage can be characterized by the following formula (4):

[0094]

[0095] where U 2 is the second detection voltage, V 2 is the second power supply voltage, R 1 is the resistance value of the first resistor, R 2 is the resistance value of the second resistor, R 3 is the resistance value of the third resistor, R 4 is the resistance value of the fourth resistor, R 5 is the resistance value of the fifth resistor, Ux is the voltage inside the battery module 420.

[0096] In some feasible embodiments, the above control circuit 410 can, according to the following formula (5), and after receiving the first detection voltage U 1 and the second detection voltage U 2 fed back by the detection circuit 400, calculate the insulation resistance R inside the battery module 420 according to the following formula (5):

[0097]

[0098] wherein, R is the resistance value of the insulation resistance inside the battery module 420, U 1 is the first detection voltage, U 2 is the second detection voltage, V 1 is the first power supply voltage, V 2 is the second power supply voltage, R 1 is the resistance value of the first resistor, R 2 is the resistance value of the second resistor, R 3 is the resistance value of the third resistor, R 4 is the resistance value of the fourth resistor, R 5 is the resistance value of the fifth resistor.

[0099] Generally speaking, the control circuit can calculate the insulation resistance inside the battery module by respectively generating and transmitting the first power supply voltage and the second power supply voltage to the detection circuit, and receiving the first detection signal and the second detection signal respectively fed back by the detection circuit, and then according to the first power supply voltage, the second power supply voltage, the first detection signal, the second detection signal and the respective resistance values of the resistor units in the detection circuit, that is, the above detection parameters, and further determine the insulation abnormality between the multiple battery cells inside the battery module and the outer shell of the battery module according to the detection parameters.

[0100] In some feasible embodiments, after the control circuit calculates the insulation resistance inside the battery module according to the above content, further, it can determine the insulation abnormality between the multiple battery cells inside the battery module and the outer shell according to 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, then 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.

[0101] It can be understood that when there are multiple battery modules in the power battery pack, the above battery module detection system connected to each battery module can detect the detection parameters (such as the above insulation resistance) inside the multiple battery modules to determine the battery module with insulation abnormality, which is convenient for repairing and replacing the faulty battery module.

[0102] In some feasible embodiments, the battery module detection system provided by the embodiments of the present application can not only determine the battery module with insulation abnormality in the power battery pack, but also determine the working abnormal battery cells in the battery module with insulation abnormality, so that the maintenance personnel can directly repair and replace the working abnormal battery cells in the battery module, thereby saving the maintenance cost.

[0103] Specifically, please refer to again Figure 4 , as Figure 4 shown, the battery module 420 includes multiple battery cells: battery cell BT1, battery cell BT2, battery cell BT3, and 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 terminal of battery module 420 at point c. It should be noted that since the above multiple battery cells are connected in series, the voltage distribution at points a, b, and c conforms to the distribution characteristics of the battery series circuit. Therefore, when the battery module 420 is working normally, the normal voltage at point c > the normal voltage at point b > the normal voltage at point a. For example, when the output voltage of the above multiple battery cells is 5 volts, the normal voltage at point a is equal to the output voltage of battery cell BT1, which is 5 volts, the normal voltage at point b is equal to the sum of the output voltages of battery cell BT1 and battery cell BT2, which is 10 volts, and the normal voltage at point c is equal to the sum of the output voltages of battery cell BT1, battery cell BT2, and battery cell BT3, which is 15 volts.

[0104] It can be understood that when multiple battery cells of the battery module 420 are normal, there is insulation between the multiple battery cells and the housing 430. At this time, the output voltage of the multiple battery cells is not applied to the housing 430, and the voltage of the housing 430 is less than the preset housing voltage threshold. This housing voltage threshold can be understood as the minimum voltage when the housing 430 is charged. When the voltage of the housing 430 is greater than this housing voltage threshold, it indicates that the housing 430 is charged. It can be understood that when a battery cell of the battery module 420 malfunctions, the malfunctioning battery cell is no longer insulated from the housing 430, that is, the malfunctioning battery cell will transmit the output voltage to the housing 430 through the insulation resistance. For example, when the battery cell BT1 has abnormalities such as leakage or micro-short circuit, the battery cell BT1 is electrically connected to the housing 430 of the battery module 420 through the insulation resistance R. Furthermore, it can be equivalent to the output voltage of the battery cell BT1 (i.e., the normal voltage at point a) acting on the housing 430 through the insulation resistance. Similarly, when the battery cell BT2 has abnormalities such as leakage or micro-short circuit, the battery cell BT2 is electrically connected to the housing 430 of the battery module 420 through the insulation resistance R. Furthermore, it can be equivalent to the output voltages of the battery cell BT1 and the battery cell BT2 (i.e., the normal voltage at point b) acting on the housing 430 through the insulation resistance. When the battery cell BT3 has abnormalities such as leakage or micro-short circuit, the battery cell BT3 is electrically connected to the housing of the battery module 420 through the insulation resistance R. Furthermore, it can be equivalent to the output voltages 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 housing 430 through the insulation resistance. That is to say, when different battery cells in the battery module 420 malfunction, the voltages acting on the housing 430 are also different. Therefore, the battery module detection system according to the embodiments of the present application can detect the battery module 420, calculate the voltage acting on the housing 430 inside the battery module 420, and determine this voltage as the insulation voltage U of the battery module 420 x This insulation voltage U x can be understood as when there is an insulation abnormality in a battery cell in the battery module 420, the malfunctioning 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 combined output voltage of the battery cell BT1 and the battery cell BT2

[0105] In some feasible embodiments, in order to determine whether there is an insulation abnormality in the battery module 420 and identify the malfunctioning battery cell in the abnormal battery module 420, the control circuit 410 can calculate the insulation voltage and insulation resistance inside the battery module 420 according to the above power supply voltage, detection voltage, and the resistance value of the resistance unit. That is, the detection parameters inside the battery module 420 include insulation voltage and insulation resistance. Then, according to this insulation resistance, it is determined whether there is an insulation abnormality inside the battery module 420, and according to this insulation equivalent voltage, the battery cell with an insulation abnormality inside the battery module 420 is identified

[0106] It can be understood that the specific implementation manner in which the above control circuit 410 calculates the insulation resistance inside the battery module 420 can refer to the above content, and the present application will not elaborate herein. Further, after the control circuit 410 calculates the insulation resistance inside the battery module 420, as can be seen from the above content, when the insulation resistance is less than a preset resistance threshold, it can be determined that there is an insulation abnormality between multiple battery cells inside the battery module 420 and the housing 430, that is, there is an abnormal operation of the battery cells among multiple battery cells inside the battery module 420. Further, the control circuit 410 can calculate the insulation voltage inside the battery module 420 according to the above power supply voltage, detection voltage, and the resistance value of the resistance unit of the detection circuit 400.

[0107] Specifically, in the case where the resistance unit of the detection circuit 400 is as Figure 4 shown, the control circuit 410 can calculate the above 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 first power supply voltage, the voltage inside the battery module 420, and the resistance values of the above respective resistors. Further, 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 content, 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 above respective resistors. Further, the detection circuit 400 can feedback the second detection voltage through the second port a2 of the control circuit 410.

[0108] It should be noted that the first detection voltage feedback by the detection circuit 400 can be characterized by the above formula (3), and the second detection voltage can be characterized by the above formula (4), and the present application will not elaborate herein.

[0109] In some feasible implementation manners, the above control circuit 410 can, according to the following formula (6), and after receiving the first detection voltage U 1 and the second detection voltage U 2 fed back by the detection circuit 400, calculate the insulation voltage U x inside the battery module 420 according to the following formula (6):

[0110]

[0111] Among them, U x is the insulation voltage, U 1 is the first detection voltage, U 2 is the second detection voltage, V 1 is the first power supply voltage, V 2 is the second power supply voltage, R 1 is the resistance value of the first resistor, R 2 is the resistance value of the second resistor, R 3 is the resistance value of the third resistor, R 4 is the resistance value of the fourth resistor, R 5 is the resistance value of the fifth resistor.

[0112] It can be understood that when multiple battery cells in the battery module 420 are working properly, these multiple battery 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. This insulation voltage threshold can be understood as the minimum value of the voltage acting on the insulation voltage and the outer shell when the battery cells in the battery module 420 work abnormally. That is to say, when the insulation voltage calculated by the control circuit 410 is less than the above insulation voltage threshold, it can be determined that there is no abnormal operation of the battery cells in the battery module 420. Further, when the insulation voltage calculated by the control circuit 410 is greater than the above insulation voltage threshold, it can be determined that there is an abnormal operation of the battery cells in the battery module 420. The battery cell with abnormal operation is no longer insulated from the outer shell 430. That is, the battery cell with abnormal operation will act the output voltage on the outer shell 430 through the insulation resistance. Therefore, the control circuit 410 can determine the abnormal battery cell according to the calculated insulation voltage and the output voltages of multiple battery cells.

[0113] Specifically, the control circuit 410 can pre-set multiple voltage threshold intervals. It should be noted that the above pre-set multiple voltage threshold intervals can be understood as multiple voltage threshold intervals corresponding to multiple battery cells in the battery module 420 respectively. For example, as Figure 4 shown, the battery module 420 includes battery cell BT1, battery cell BT2 and battery cell BT3. From the above content, it can be known that when the output voltages of the above 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 outer shell 430 through the insulation resistance. At this time, the calculated insulation voltage is close to the output voltage of the battery cell BT1, which is 5 volts. Therefore, the control circuit 410 can determine the voltage threshold interval corresponding to the battery cell BT1 as an interval with 5 volts as the mean value, for example, 3 volts to 7 volts. It can be understood that when the calculated insulation voltage of the battery module 420 is 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 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 range corresponding to the battery cell BT2 as a range with 10 volts as the mean value, for example, 8 volts to 12 volts. It can be understood that when the calculated insulation voltage of the battery module 420 is 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 cells BT2 and BT1, and the output voltages of the battery cells BT1, BT2, and BT3 are added 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 range corresponding to the battery cell BT3 as a range with 15 volts as the mean value, for example, 13 volts to 17 volts. It can be understood that when the calculated insulation voltage of the battery module 420 is equal to 14 volts, it can be determined that the battery cell BT3 of the battery module 420 is abnormal.

[0116] Generally speaking, the control circuit 410 can determine the voltage threshold range corresponding to each battery cell according to the output voltages of the battery cells connected in series inside the battery module 420. The voltage threshold ranges of the above battery cells BT1, BT2, and BT3 are only examples, and this application will not list them one by one here. It should be noted that in order to avoid misjudging the battery cells with abnormal working conditions, when the control circuit 410 pre-sets the voltage threshold ranges corresponding to each battery cell, it should ensure that the voltage threshold ranges corresponding to each battery cell do not overlap with each other.

[0117] It can be understood that after the control circuit 410 calculates the insulation voltage inside the battery module 420, it can determine one voltage threshold range corresponding to the insulation voltage as the target voltage threshold range among a plurality of pre-set voltage threshold ranges. Among them, the target voltage threshold range can be understood as a voltage threshold range including the calculated insulation voltage. For example, assuming that the voltage threshold range corresponding to the battery cell BT1 is 3 volts to 7 volts, when the control circuit 410 calculates that the insulation voltage is 7 volts, it can be determined that the voltage threshold range of 3 volts to 7 volts corresponding to the battery cell BT1 is the above target voltage threshold range. Further, the control circuit 410 can determine the battery cell corresponding to the target voltage threshold range as the battery cell with an insulation abnormality, that is, determine the above battery cell BT1 as the battery cell with an insulation abnormality.

[0118] In some feasible implementation manners, please refer toFigure 5 , Figure 5 is another schematic structural diagram of the detection circuit provided by the embodiment of the present application. As Figure 5 shown, the detection circuit 500 further includes a first capacitor C 1 and a second capacitor C 2 . Among them, the first capacitor C 1 is connected in parallel with the above-mentioned third resistor R 3 . One end of the second capacitor C 2 is connected to the other end of the fourth resistor R 4 , and the other end of the second capacitor C 2 is grounded. It should be noted that the above-mentioned first capacitor C 1 is a filter capacitor, which can filter out the interference signals in the detection circuit 500 to avoid interfering with the detection parameters. The second capacitor C 2 is the parasitic capacitance in the detection circuit 500.

[0119] In some feasible embodiments, please refer to Figure 5 again. As Figure 5 shown, the detection circuit 500 further further includes a first diode D 1 and a second diode D 2 . Among them, one end of the first diode D 1 is connected to the first port a1 of the control circuit, and the other end of the first diode D 1 is connected to one end of the second resistor R 2 . One end of the above-mentioned second diode D 2 is connected to the second port a2 of the control circuit, and the other end of the second diode D 2 is grounded. It should be noted that the above-mentioned first diode D 1 can be a reverse diode, which can prevent the voltage in the detection circuit 500 from affecting the first port a1 of the control circuit. The above-mentioned second diode D 2 can be a voltage stabilizing diode, which can prevent the voltage in the detection circuit 500 from affecting the second port a2 of the control circuit. Thus, the stability of the detection circuit 500 is ensured.

[0120] In some feasible embodiments, from the above content, it can be seen that the detection circuit in the battery module detection system is composed of resistor-capacitor components (resistors and capacitors), with a simple structure and easy to implement. Moreover, the cost of resistor-capacitor components is relatively low, thereby saving the development cost.

[0121] In the embodiments of the present application, when a power battery pack includes a plurality of battery modules, the insulation resistance of each of the plurality of battery modules can be detected respectively through a battery module detection system connected to each battery module, so as to determine the insulation abnormality inside the plurality of battery modules according to the insulation resistance and a preset resistance threshold, and further determine the battery modules with insulation abnormality among the plurality of battery modules. Further, the battery modules with insulation abnormality can be repaired and replaced. It can be understood 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 further, according to the insulation voltage of the battery module and a plurality of preset voltage threshold ranges, determine the battery cells with insulation abnormality among the plurality of battery cells of the battery module, which is convenient for maintenance personnel to repair and replace the abnormal battery cells in the battery module, and improves the safety and stability of the battery module.

[0122] The embodiments of the present application also provide a method for detecting a battery module. Please refer to Figure 6 , Figure 6 which is a schematic flowchart of a process of the method for detecting a battery module provided by the present application. The method for detecting a battery module provided by the embodiments of the present application is applicable to Figures 3 to 5 the battery module detection system shown in Figure 6 . It should be noted that Figures 3 to 5 the detection method shown in

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

[0124] In some feasible embodiments, the above detection circuit includes a resistance unit. Further, from the above content, it can be known that the detection circuit can receive the power supply voltage generated by the control circuit. When the internal voltage of the battery module changes, causing the voltage of the outer shell to also change, the detection circuit can generate a corresponding detection voltage under the action of the voltage of the outer shell and the power supply voltage.

[0125] The specific implementation manner of the above S101 can refer to the implementation manner executed by the control circuit in the above Figures 3 to 5 , and the embodiments of the present application will not elaborate herein.

[0126] S102. Determine the 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 above resistance unit can generate different detection voltages under the voltages of different outer casings and the power supply voltage. Therefore, the detection circuit can feedback the detection voltage to the control circuit, so that the control circuit can inversely deduce the internal voltage of the battery module according to the generated power supply voltage, the received detection voltage, and the resistance value of the resistance unit in the detection circuit, and then determine the insulation abnormality inside the battery module.

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

[0129] In some feasible embodiments, when the above detection parameter includes 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 outer casing, and feedback it to the above control circuit. Further, after receiving the first detection voltage, the control circuit combines the above 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, receive the first detection signal and the second detection signal respectively feedback by the detection circuit, and then calculate the insulation resistance inside the battery module, that is, the above detection parameter, according to the first power supply voltage, the second power supply voltage, the first detection signal, the second detection signal, and the respective resistance values of the resistance units in the detection circuit, and then determine the insulation abnormality between multiple battery cells inside the battery module and the outer casing of the battery module according to the detection parameter.

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

[0132] In some feasible embodiments, the battery module detection method provided by the embodiments of the present application further includes presetting a voltage threshold interval corresponding to each battery cell, and after calculating the insulation voltage inside the battery module, determining, from a plurality of preset voltage threshold intervals, a voltage threshold interval corresponding to the insulation voltage as the target voltage threshold interval. Further, the control circuit may determine the battery cells corresponding to the target voltage threshold interval as the battery cells with insulation abnormalities, so that maintenance personnel can directly repair and replace the battery cells with abnormal operation in the battery module, thereby saving maintenance costs.

[0133] The specific implementation manner of S102 above may refer to the implementation manner executed by the control circuit in the above Figures 3 to 5 and will not be elaborated herein in the embodiments of the present application.

[0134] The embodiments of the present application further provide a computer-readable storage medium storing a computer program, which when executed by a processor, implements the operations performed by the control circuit in the foregoing method in any of the above Figure 6 and its possible method embodiments.

[0135] The embodiments of the present application further provide a computer program product, which when read and executed by a computer, executes the operations performed by the control circuit in the foregoing method in any of the above Figure 6 and its possible method embodiments.

[0136] The embodiments of the present application further provide a power supply device. Please refer to Figure 7 , Figure 7 which is a schematic structural diagram of the power supply device provided by the embodiments of the present application. Figure 7 In this case, the power supply device includes a battery module, a battery management system, and the battery module detection system in the above various possible embodiments. Among them, the battery module is electrically connected to the 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 a detection result according to the insulation abnormalities inside the battery module. The battery module detection system is connected to the battery management system and can send the above detection result to the battery management system. Further, the battery management system can output an abnormal prompt or a normal prompt according to the detection result.

[0137] In some feasible embodiments, the above battery module includes at least two battery cells connected in series. Specifically, please refer to Figure 3 and Figure 4 for the specific implementation of the battery module shown, which will not be elaborated herein in the present application.

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

[0139] The embodiments of this application also provide a battery information collector, which includes the battery module detection system in the above various possible embodiments.

[0140] It can be seen that the content in the above embodiments of the battery module detection system is applicable to the embodiments of this battery information collector. The functions specifically implemented in the embodiments of this battery information collector are the same as those in the above embodiments of the battery module detection system, and the beneficial effects achieved are also the same as those in the above embodiments of the battery module detection system.

[0141] The embodiments of this application also provide an electric device, which includes the power supply device in the above various possible embodiments. Exemplarily, in some application scenarios, the above electric device can be an electric vehicle, a household appliance, a terminal device, or other power-consuming devices with a battery module. The embodiments of this application do not limit this.

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

[0143] It should be noted that for the foregoing method embodiments, for the sake of simple description, they are all expressed as a series of action combinations. However, those skilled in the art should know that this application is not limited by the described action sequence, because according to this application, certain steps may be implemented in other sequences or simultaneously. Secondly, those skilled in the art should also know that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily essential to this application.

[0144] In the embodiments provided by this application, it should be understood that the disclosed system can be implemented in other ways. For example, the above-described system embodiments are merely illustrative. For example, the above module division is only a logical function division. In actual implementation, there can be other division methods. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point, the displayed or discussed coupling or direct coupling or communication connection between each other can be through some interfaces. The indirect coupling or communication connection of the system or unit can be in an electrical or other form.

[0145] The modules described above as separate components may or may not be physically separated. 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 can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

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

[0147] The embodiments of the present application have been introduced in detail above. Specific examples are used in this article to elaborate on the principle and implementation manner of the present application. The description of the above embodiments is only used to help understand the present application and its core idea; at the same time, for those of ordinary skill in the art, according to the idea of the present application, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation to the present application.

Claims

1. A battery module detection system, characterized in that, the system includes a control circuit and a detection circuit, the detection circuit is used for electrically connecting to the housing of the battery module, and the control circuit is connected to the detection circuit; the control circuit is used for controlling the power supply voltage to be transmitted to the detection circuit and obtaining the detection voltage fed back by the detection circuit; the detection circuit includes a resistance unit; the control circuit is used for determining the 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; the resistance 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, and 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 ends of the third resistor, 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; the control circuit is used for transmitting the power supply voltage through the first port, and the control circuit is used for obtaining the detection voltage through the second port.

2. The system according to claim 1, characterized in that, the power supply voltage includes a first power supply voltage, and the detection voltage includes the first detection voltage fed back by the detection circuit when the power supply voltage is the first power supply voltage; the detection parameters inside the battery module include insulation resistance; the control circuit is used for determining the insulation resistance inside the battery module according to the first power supply voltage, the first detection voltage and the resistance value of the resistance unit, and determining whether there is an insulation abnormality between the multiple battery cells inside the battery module and the housing of the battery module according to the insulation resistance inside the battery module and a preset resistance threshold.

3. The system according to claim 1, 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 insulation resistance; the control circuit is used for determining the insulation resistance inside the battery module 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 determining whether there is an insulation abnormality between the multiple battery cells inside the battery module and the housing of the battery module according to the insulation resistance inside the battery module and a preset resistance threshold.

4. The system according to claim 3, characterized in that, The detection parameters inside the battery module further include the insulation voltage; The control circuit is configured to determine the insulation voltage inside the battery module 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. When the insulation resistance is less than the preset resistance threshold, the control circuit determines the battery cells with insulation anomalies from multiple battery cells inside the battery module according to the insulation voltage inside the battery module.

5. The system according to claim 4, wherein, when the insulation resistance is less than the preset resistance threshold, the control circuit determines the battery cells corresponding to the obtained target voltage threshold range inside the battery module as the battery cells with insulation anomalies.

6. The system according to claim 2, wherein, the control circuit is configured to determine the insulation resistance inside the battery module according to the first power supply voltage, the first detection voltage, and the resistance value of the resistance unit, including: the control circuit calculates the insulation resistance inside the battery module according to the following formula: Wherein, is the resistance value of the insulation resistance, is the first detection voltage, is the first power supply voltage, is the resistance value of the second resistor, is the resistance value of the third resistor, is the resistance value of the fourth resistor, is the resistance value of the fifth resistor.

7. The system according to any one of claims 3-5, wherein, the control circuit is configured to determine the insulation resistance inside the battery module 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 calculates the insulation resistance inside the battery module according to the following formula: Wherein, is the resistance value of the insulation resistance, is the first detection voltage, is the second detection voltage, is the first power supply voltage, is the second power supply voltage, is the resistance value of the second resistor, is the resistance value of the third resistor, is the resistance value of the fourth resistor, is the resistance value of the fifth resistor.

8. The system according to claim 7, wherein, the control circuit calculates the insulation voltage inside the battery module according to the following formula: Wherein, is the insulation voltage, is the first detection voltage, is the second detection voltage, is the first power supply voltage, is the second power supply voltage, is the resistance value of the second resistor, is the resistance value of the third resistor, is the resistance value of the fourth resistor, is the resistance value of the fifth resistor.

9. The system according to claim 1, wherein, the detection circuit further includes a first capacitor and a second capacitor; the first capacitor is connected in parallel with 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.

10. The system according to claim 9, wherein, 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.

11. A method for detecting a battery module, wherein, the method is applied to the control circuit in the battery module detection system according to any one of claims 1-10. The battery module detection system further includes a detection circuit, the detection circuit is electrically connected to the outer shell of the battery module, and the control circuit is connected to the detection circuit. The method includes: controlling the power supply voltage to be transmitted to the detection circuit and obtaining the detection voltage fed back by the detection circuit; the detection circuit includes a resistance unit; Determine the 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.

12. The method according to claim 11, wherein, 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 when the power supply voltage is the first power supply voltage; the detection parameters inside the battery module include insulation resistance; the determining the 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 includes: determining the insulation resistance inside the battery module according to the first power supply voltage, the first detection voltage, and the resistance value of the resistance unit, and determining whether there is an insulation abnormality between the multiple battery cells inside the battery module and the outer shell of the battery module according to the insulation resistance inside the battery module and a preset resistance threshold.

13. The method according to claim 11, wherein, 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 insulation resistance; the determining the 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 includes: determining the insulation resistance inside the battery module 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 determining whether there is an insulation abnormality between the multiple battery cells inside the battery module and the outer shell of the battery module according to the insulation resistance inside the battery module and a preset resistance threshold.

14. The method according to claim 13, wherein, the detection parameters inside the battery module further include insulation voltage; the determining the 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 includes: The control circuit is used to determine the insulation voltage inside the battery module 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. When the insulation resistance is less than the preset resistance threshold, according to the insulation voltage inside the battery module, the battery cells with insulation anomalies are determined from multiple battery cells inside the battery module.

15. The method according to claim 14, wherein, when the insulation resistance is less than the preset resistance threshold, according to the insulation voltage inside the battery module, determining the battery cells with insulation anomalies from multiple battery cells inside the battery module includes: when the insulation resistance is less than the preset resistance threshold, the battery cells inside the battery module corresponding to the obtained target voltage threshold range are determined as the battery cells with insulation anomalies.

16. A computer-readable storage medium, wherein, a computer program is stored in the computer-readable storage medium, and the computer program is adapted to be loaded and executed by a processor so that a computer device having the processor executes the method according to any one of claims 11-15.

17. A computer program product, wherein, when the computer program product is executed by a processor, the method according to any one of claims 11-15 will be implemented.

18. A battery information collector, wherein, the battery information collector includes the battery module detection system according to any one of claims 1-10.

19. A power supply device, wherein, it includes a battery module, a battery management system, and the battery module detection system according to any one of claims 1-10 or the battery information collector according to claim 18; the battery module detection system is used to detect the insulation anomalies inside the battery module, generate a detection result according to the insulation anomalies inside the battery module, and send the detection result to the battery management system; the battery management system is used to output an anomaly prompt or a normal prompt according to the detection result.

20. The power supply device according to claim 19, wherein, the battery module includes at least two serially connected battery cells.

21. An electric device, the electric device includes the power supply device according to claim 19 or claim 20.

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