Insulation testing method and device for battery system and battery system

Abstract

The present application proposes a battery system insulation testing method, device, and battery system, including: obtaining a first bridge arm voltage value and a second bridge arm voltage value, wherein the first bridge arm voltage value is the voltage value across the first bridge arm when the first bridge arm is on and the second bridge arm is off, and the second bridge arm voltage value is the voltage value across the second bridge arm when the second bridge arm is on and the first bridge arm is off; based on the first bridge arm voltage value, the second bridge arm voltage value, the first bridge arm resistance, the second bridge arm resistance, the first battery pack voltage, and the second battery pack voltage, obtaining the positive bridge arm insulation resistance value and the negative bridge arm insulation resistance value of the battery system. No additional system insulation detection circuit is required, and the battery system insulation test is completed without incurring additional costs, thereby ensuring the high-voltage safety of the equipment installed with the battery system.

Description

Technical Field

[0001] The present application relates to the field of batteries, and more specifically, to an insulation testing method and device for a battery system, and a battery system. Background Art

[0002] As people's living standards improve, their travel needs are increasing. Driven by energy conservation and emission reduction initiatives, new energy transportation systems are rapidly developing to meet this growing demand. These include electric bicycles, electric motorcycles, and electric vehicles.

[0003] Taking electric vehicles as an example, to alleviate mileage anxiety among car owners and increase their range, a portable on-board battery pack can be connected in series with the main battery pack. The series connection significantly increases the voltage level of the portable on-board battery pack and the main battery pack. The higher the voltage level, the greater the potential safety risks. To ensure the high-voltage safety of the entire vehicle, real-time insulation monitoring of the main battery pack and the series-connected portable on-board battery pack system is required. Specifically, how to complete insulation monitoring has become a difficult problem that continues to attract attention from those skilled in the art. Summary of the Invention

[0004] The purpose of this application is to provide a battery system insulation testing method, device and battery system to solve the above problems.

[0005] In order to achieve the above objectives, the technical solutions adopted in the embodiments of the present application are as follows:

[0006] In a first aspect, embodiments of the present application provide an insulation testing method for a battery system. The battery system includes a first battery pack and a second battery pack, the first battery pack being connected in series with the second battery pack. The first battery pack is configured with a first battery management device and an insulation detection circuit. The insulation detection circuit includes a first bridge arm and a second bridge arm. The first battery management device is configured to switch the first bridge arm and the second bridge arm between on and off states, and the first battery management device is further configured to collect voltages across the first bridge arm and the second bridge arm.

[0007] The method comprises:

[0008] Obtain a first bridge arm voltage value and a second bridge arm voltage value, wherein the first bridge arm voltage value is a voltage value across the first bridge arm when the first bridge arm is turned on and the second bridge arm is turned off, and the second bridge arm voltage value is a voltage value across the second bridge arm when the second bridge arm is turned on and the first bridge arm is turned off;

[0009] Based on the first bridge arm voltage value, the second bridge arm voltage value, the first bridge arm resistance, the second bridge arm resistance, the first battery pack voltage and the second battery pack voltage, the positive bridge arm insulation resistance value and the negative bridge arm insulation resistance value of the battery system are obtained.

[0010] Optionally, the positive electrode of the first battery pack is connected to the negative electrode of the second battery pack, the first bridge arm resistance is the positive bridge arm resistance of the first battery pack, the first bridge arm voltage value is the positive bridge arm terminal voltage of the first battery pack, the second bridge arm resistance is the negative bridge arm resistance of the first battery pack, and the second bridge arm voltage value is the negative bridge arm terminal voltage of the first battery pack.

[0011] Optionally, the insulation resistance value of the positive bridge arm and the insulation resistance value of the negative bridge arm of the battery system are obtained according to the following formula;

[0012]

[0013]

[0014] Among them, Rx represents the insulation resistance value of the positive bridge arm of the battery system, Ry represents the insulation resistance value of the negative bridge arm of the battery system, V1 represents the voltage of the first battery pack, V2 represents the voltage of the second battery pack, Vp represents the positive bridge arm voltage value of the first battery pack, Vn represents the negative bridge arm voltage value of the first battery pack, Rp represents the positive bridge arm resistance of the first battery pack, and Rn represents the negative bridge arm resistance of the first battery pack.

[0015] Optionally, the negative electrode of the first battery pack is connected to the positive electrode of the second battery pack, the first bridge arm resistance is the positive bridge arm resistance of the first battery pack, the first bridge arm voltage value is the positive bridge arm terminal voltage of the first battery pack, the second bridge arm resistance is the negative bridge arm resistance of the first battery pack, and the second bridge arm voltage value is the negative bridge arm terminal voltage of the first battery pack.

[0016] Optionally, the insulation resistance value of the positive bridge arm and the insulation resistance value of the negative bridge arm of the battery system are obtained according to the following formula;

[0017]

[0018]

[0019] Among them, Rx represents the insulation resistance value of the positive bridge arm of the battery system, Ry represents the insulation resistance value of the negative bridge arm of the battery system, V1 represents the voltage of the first battery pack, V2 represents the voltage of the second battery pack, Vp represents the positive bridge arm voltage value of the first battery pack, Vn represents the negative bridge arm voltage value of the first battery pack, Rp represents the positive bridge arm resistance of the first battery pack, and Rn represents the negative bridge arm resistance of the first battery pack.

[0020] Optionally, before obtaining the first bridge arm voltage value and the second bridge arm voltage value, the method further includes:

[0021] An internal insulation test is performed on the first battery pack by using the first battery management device and the insulation detection circuit to obtain the first bridge arm resistance and the second bridge arm resistance.

[0022] Optionally, the second battery pack includes N portable battery packs, where N is greater than or equal to 1.

[0023] In a second aspect, an embodiment of the present application provides an insulation testing device for a battery system. The battery system includes a first battery pack and a second battery pack, the first battery pack and the second battery pack being connected in series. The first battery pack is configured with a first battery management device and an insulation detection circuit. The insulation detection circuit includes a first bridge arm and a second bridge arm. The first battery management device is configured to switch the first bridge arm and the second bridge arm between the on and off states. The first battery management device is further configured to collect voltages across the first bridge arm and the second bridge arm.

[0024] The device comprises:

[0025] a monitoring unit, configured to obtain a first bridge arm voltage value and a second bridge arm voltage value, wherein the first bridge arm voltage value is a voltage value across the first bridge arm when the first bridge arm is turned on and the second bridge arm is turned off, and the second bridge arm voltage value is a voltage value across the second bridge arm when the second bridge arm is turned on and the first bridge arm is turned off;

[0026] A processing unit is used to obtain a positive bridge arm insulation resistance value and a negative bridge arm insulation resistance value of the battery system based on the first bridge arm voltage value, the second bridge arm voltage value, the first bridge arm resistance, the second bridge arm resistance, the first battery pack voltage, and the second battery pack voltage.

[0027] In a third aspect, an embodiment of the present application provides a storage medium on which a computer program is stored. When the computer program is executed by a first battery management device, the above method is implemented.

[0028] In a fourth aspect, an embodiment of the present application provides a battery system, comprising: a memory, a first battery pack and a second battery pack configured with a first battery management device, the first battery pack and the second battery pack being connected in series, the memory being used to store one or more programs; when the one or more programs are executed by the first battery management device, the above-mentioned method is implemented.

[0029] Compared to the prior art, the embodiments of the present application provide a battery system insulation testing method, device, and battery system, including: obtaining a first bridge arm voltage value and a second bridge arm voltage value, wherein the first bridge arm voltage value is the voltage value across the first bridge arm when the first bridge arm is turned on and the second bridge arm is turned off, and the second bridge arm voltage value is the voltage value across the second bridge arm when the second bridge arm is turned on and the first bridge arm is turned off; based on the first bridge arm voltage value, the second bridge arm voltage value, the first bridge arm resistance, the second bridge arm resistance, the first battery pack voltage, and the second battery pack voltage, obtaining the positive bridge arm insulation resistance value and the negative bridge arm insulation resistance value of the battery system. No additional system insulation detection circuit is required, and the battery system insulation test is completed without incurring additional costs, thereby ensuring the high-voltage safety of the equipment installed with the battery system.

[0030] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0032] Figure 1 A schematic structural diagram of a battery system provided in an embodiment of the present application;

[0033] Figure 2 This is one of the schematic diagrams of the insulation detection circuit of the battery system provided in an embodiment of the present application;

[0034] Figure 3 This is one of the schematic diagrams of the insulation detection circuit of the battery system provided in an embodiment of the present application;

[0035] Figure 4 A schematic flow chart of an insulation testing method for a battery system provided in an embodiment of the present application;

[0036] Figure 5 Provided in the embodiments of this application Figure 2 One of the corresponding bridge arm on-off state diagrams;

[0037] Figure 6 Provided in the embodiments of this application Figure 2 One of the corresponding bridge arm on-off state diagrams;

[0038] Figure 7 Provided in the embodiments of this application Figure 3One of the corresponding bridge arm on-off state diagrams;

[0039] Figure 8 Provided in the embodiments of this application Figure 3 One of the corresponding bridge arm on-off state diagrams;

[0040] Figure 9 This is a flow chart of a method for insulation testing of a battery system according to an embodiment of the present application;

[0041] Figure 10 A schematic diagram of a unit of an insulation testing device for a battery system provided in an embodiment of the present application;

[0042] Figure 11 This is one of the structural schematic diagrams of a battery system provided in an embodiment of the present application.

[0043] In the figure: 10 - first battery management device; 11 - memory; 12 - bus; 13 - communication interface; 201 - monitoring unit; 202 - processing unit. DETAILED DESCRIPTION

[0044] To make the objectives, technical solutions, and advantages of the embodiments of the present application more clear, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Generally, the components of the embodiments of the present application described and shown in the drawings herein can be arranged and designed in various different configurations.

[0045] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for protection, but merely represents selected embodiments of the present application. All other embodiments obtained by persons of ordinary skill in the art based on the embodiments in the present application without creative work are within the scope of protection of the present application.

[0046] It should be noted that similar reference numerals and letters represent similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings. At the same time, in the description of this application, the terms "first", "second", etc. are only used to distinguish the description and should not be understood as indicating or implying relative importance.

[0047] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply the existence of any such actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article, or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or device. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of other identical elements in the process, method, article, or device comprising the element.

[0048] In the description of this application, it should be noted that the terms "upper", "lower", "inside", "outside", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, or are the orientations or positional relationships in which the product of the application is usually placed when in use. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they should not be understood as limitations on this application.

[0049] It should also be noted that, in the description of this application, unless otherwise expressly specified or limited, the terms "disposed" and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections, or electrical connections; direct connections, indirect connections through an intermediate medium, or internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on the specific circumstances.

[0050] The following describes some embodiments of the present application in detail with reference to the accompanying drawings. In the absence of conflict, the following embodiments and features therein may be combined with each other.

[0051] Taking electric vehicles as an example, to alleviate range anxiety among car owners and increase their range, a portable on-board battery pack can be connected in series with the main battery pack. This connection significantly increases the voltage level, and the increasing voltage level also poses greater safety risks. To ensure the high-voltage safety of the entire vehicle, real-time insulation monitoring of the main battery pack and the series-connected portable on-board battery pack is required. The insulation resistance value between the system's high-voltage circuit and the vehicle ground is promptly reported.

[0052] Please refer to Figure 1 , Figure 1 This is a schematic diagram of the structure of a battery system provided in an embodiment of the present application. Figure 1 As shown, the battery system includes a first battery pack ESS1 and a second battery pack ESS2. ESS1 may be a standard vehicle-mounted battery pack, and ESS2 may be an optional portable battery pack.

[0053] The first battery pack ESS 1 is connected in series with the second battery pack ESS 2. Optionally, the battery system further includes a power distribution unit (PDU). Figure 1 As shown, the first battery pack ESS 1 and the second battery pack ESS 2 can be connected in series via a power distribution unit.

[0054] The P-ECU in the power distribution unit can manage the closed or open states of the switches S4, S5, and S6, thereby switching the connection relationship between the first battery pack ESS 1 and the second battery pack ESS 2.

[0055] It should be understood that in a battery system, two battery pack devices (the first battery pack ESS 1 and the second battery pack ESS 2 ) cannot perform insulation testing at the same time, otherwise they will interfere with each other and cannot be accurately measured.

[0056] In this embodiment, the first battery pack, ESS 1, serves as a standard on-board battery pack. Its BMS 1 is fully functional and can independently perform insulation testing. The second battery pack, ESS 2, serves as an optional portable battery pack. Its BMS 2 is not designed with insulation testing capabilities and cannot independently perform insulation testing. However, ESS 2 can be connected in series with ESS 1, allowing BMS 1 to perform insulation testing on the entire battery system, which can also achieve cost savings.

[0057] Specifically, the first battery pack ESS 1 is equipped with a first battery management device (BMS1) and an insulation detection circuit. The insulation detection circuit includes a first bridge arm and a second bridge arm. The first battery management device (BMS1) is used to switch the first and second bridge arms between on and off states and to collect voltages across the first and second bridge arms. Optionally, the insulation detection circuit is integrated into the PCB of the BMS1 and is part of the internal structure of the first battery pack ESS 1. The first battery management device (BMS1) can be a battery management system.

[0058] Please continue to refer to Figure 1 The battery system may further include switches S1 to S9. Figure 1 The switches S1 to S9 in FIG. 1 are external relays relative to the first battery pack ESS 1 and the second battery pack ESS 2 .

[0059] Please refer to Figure 2 and Figure 3 , Figure 2 and Figure 3 This is a schematic diagram of the insulation detection circuit of the battery system provided in the embodiment of the present application. Figure 2 As shown, the positive electrode of the first battery pack ESS 1 is connected to the negative electrode of the second battery pack ESS 2 to form a series connection; Figure 3 As shown, the negative electrode of the first battery pack ESS 1 is connected to the positive electrode of the second battery pack ESS 2 to form a series connection.

[0060] Sp and Sn are relays integrated into the PCB of BMS 1, used to switch the on / off states of the first and second bridge arms during auxiliary insulation testing. The first bridge arm resistance is the positive bridge arm resistance Rp of the first battery pack, and the first bridge arm voltage is the positive bridge arm terminal voltage of the first battery pack. The second bridge arm resistance is the negative bridge arm resistance Rn of the first battery pack, and the second bridge arm voltage is the negative bridge arm terminal voltage of the first battery pack.

[0061] It should be understood that the first battery pack ESS 1, as a standard on-board battery pack, carries a fully functional BMS 1 capable of independent insulation testing, thereby measuring the positive arm resistance Rp and the negative arm resistance Rn of the first battery pack. The insulation resistance values ​​Rx and Ry of the positive arm of the battery system shown in the figure are the data required for insulation testing based on BMS 1.

[0062] It should be understood that Figure 1 、 Figure 2 as well as Figure 3 The structure shown is only a schematic diagram of a portion of the battery system. The battery system may also include Figure 1 、 Figure 2 as well as Figure 3 More or fewer components than shown, or with Figure 1 、 Figure 2 as well as Figure 3 Different configurations shown. Figure 1 、 Figure 2 as well as Figure 3 Each component shown in the figure can be implemented by hardware, software or a combination thereof.

[0063] The insulation testing method of a battery system provided in the embodiment of the present application can be applied to, but not limited to, Figure 1 、 Figure 2 as well as Figure 3 For the battery system shown in the figure, please refer to Figure 4 The insulation test method of the battery system includes: S102 and S103, which are described in detail as follows.

[0064] S102, obtaining a first bridge arm voltage value and a second bridge arm voltage value.

[0065] The first bridge arm voltage value is the voltage value at both ends of the first bridge arm when the first bridge arm is turned on and the second bridge arm is turned off, and the second bridge arm voltage value is the voltage value at both ends of the second bridge arm when the second bridge arm is turned on and the first bridge arm is turned off.

[0066] Please refer to Figure 5 、 Figure 6 、 Figure 7 as well as Figure 8 , Figure 5 and Figure 6 Provided in the embodiments of this application Figure 2 The corresponding bridge arm on-off state diagram, Figure 7 and Figure 8 Provided in the embodiments of this application Figure 3 Schematic diagram of the corresponding bridge arm on-off status.

[0067] like Figure 5 、 Figure 6 、 Figure 7 as well as Figure 8 As shown, when the switch Sp is closed, the first bridge arm is turned on; when the switch Sp is opened, the first bridge arm is opened; when the switch Sn is closed, the second bridge arm is turned on; when the switch Sn is opened, the second bridge arm is opened.

[0068] When the switch Sp is closed and the switch Sn is open, the voltage value Vp across the first bridge arm is the first bridge arm voltage value; when the switch Sp is open and the switch Sn is closed, the voltage value Vn across the second bridge arm is the second bridge arm voltage value.

[0069] S103 , based on the first bridge arm voltage value, the second bridge arm voltage value, the first bridge arm resistance, the second bridge arm resistance, the first battery pack voltage, and the second battery pack voltage, obtain the positive bridge arm insulation resistance value and the negative bridge arm insulation resistance value of the battery system.

[0070] It should be understood that the first bridge arm voltage value and the second bridge arm voltage value can be obtained based on the first battery management device BMS1 and the insulation detection circuit in the first battery pack ESS1, without the need for an additional system insulation detection circuit. Without adding additional cost, the positive bridge arm insulation resistance value Rx and the negative bridge arm insulation resistance value Ry of the battery system can be directly obtained based on the first bridge arm voltage value, the second bridge arm voltage value, the first bridge arm resistance, the second bridge arm resistance, the first battery pack voltage, and the second battery pack voltage, completing the battery system insulation test and ensuring the high-voltage safety of the equipment installed with the battery system.

[0071] In summary, the insulation testing method for a battery system provided in an embodiment of the present application includes: obtaining a first bridge arm voltage value and a second bridge arm voltage value, wherein the first bridge arm voltage value is the voltage value across the first bridge arm when the first bridge arm is turned on and the second bridge arm is turned off, and the second bridge arm voltage value is the voltage value across the second bridge arm when the second bridge arm is turned on and the first bridge arm is turned off; based on the first bridge arm voltage value, the second bridge arm voltage value, the first bridge arm resistance, the second bridge arm resistance, the first battery pack voltage, and the second battery pack voltage, obtaining the positive bridge arm insulation resistance value and the negative bridge arm insulation resistance value of the battery system. No additional insulation detection circuit is required for the system, and the battery system insulation test is completed without incurring any additional cost, thereby ensuring the high-voltage safety of the equipment installed with the battery system.

[0072] Please refer to Figure 2 In one possible implementation, the positive electrode of the first battery pack ESS1 is connected to the negative electrode of the second battery pack ESS2, the first bridge arm resistance is the positive bridge arm resistance Rp of the first battery pack, the first bridge arm voltage value is the positive bridge arm terminal voltage Vp of the first battery pack, the second bridge arm resistance is the negative bridge arm resistance Rn of the first battery pack, and the second bridge arm voltage value is the negative bridge arm terminal voltage Vn of the first battery pack.

[0073] Specifically, please refer to Figure 5 When the switch Sp is open and the switch Sn is closed, the voltage across the second bridge arm Vn is the second bridge arm voltage value. At this time, the voltage at the negative bridge arm of the series battery system is Vn, and the voltage at the positive bridge arm of the system is V1+V2-Vn, resulting in the following equation ①:

[0074]

[0075] Please refer to Figure 6 When the switch Sp is closed and the switch Sn is open, the voltage Vp across the first bridge arm is the first bridge arm voltage. At this time, the voltage at the negative bridge arm of the series battery system is V1-Vp, and the voltage at the positive bridge arm of the system is V2+Vp, resulting in the following equation ②:

[0076]

[0077] Combining equations ① and ②, the insulation resistance value Rx of the positive bridge arm and the insulation resistance value Ry of the negative bridge arm can be obtained. Specifically, the insulation resistance value of the positive bridge arm and the insulation resistance value of the negative bridge arm of the battery system are obtained according to the following formulas;

[0078]

[0079]

[0080] Among them, Rx represents the insulation resistance value of the positive bridge arm of the battery system, Ry represents the insulation resistance value of the negative bridge arm of the battery system, V1 represents the voltage of the first battery pack, V2 represents the voltage of the second battery pack, Vp represents the positive bridge arm voltage value of the first battery pack, Vn represents the negative bridge arm voltage value of the first battery pack, Rp represents the positive bridge arm resistance of the first battery pack, and Rn represents the negative bridge arm resistance of the first battery pack.

[0081] Please refer to Figure 3 In one possible implementation, the negative electrode of the first battery pack ESS1 is connected to the positive electrode of the second battery pack ESS2, the first bridge arm resistance is the positive bridge arm resistance Rp of the first battery pack, the first bridge arm voltage value is the positive bridge arm terminal voltage Vp of the first battery pack, the second bridge arm resistance is the negative bridge arm resistance Rn of the first battery pack, and the second bridge arm voltage value is the negative bridge arm terminal voltage Vn of the first battery pack.

[0082] Specifically, please refer to Figure 7 When the switch Sp is open and the switch Sn is closed, the voltage Vn across the second bridge arm is the second bridge arm voltage. At this time, the voltage at the negative bridge arm of the series battery system is Vn+V2, and the voltage at the positive bridge arm of the system is V1-Vn, resulting in the following equation ③:

[0083]

[0084] Please refer to Figure 8 When the switch Sp is closed and the switch Sn is open, the voltage across the first bridge arm Vp is the first bridge arm voltage value. At this time, the voltage at the negative bridge arm of the series battery system is V1+V2-Vp, and the voltage at the positive bridge arm of the system is Vp, resulting in the following equation ④:

[0085]

[0086] Combining equations ③ and ④, the insulation resistance value Rx of the positive bridge arm and the insulation resistance value Ry of the negative bridge arm can be obtained. Specifically, the insulation resistance value of the positive bridge arm and the insulation resistance value of the negative bridge arm of the battery system are obtained according to the following formulas;

[0087]

[0088]

[0089] Among them, Rx represents the insulation resistance value of the positive bridge arm of the battery system, Ry represents the insulation resistance value of the negative bridge arm of the battery system, V1 represents the voltage of the first battery pack, V2 represents the voltage of the second battery pack, Vp represents the positive bridge arm voltage value of the first battery pack, Vn represents the negative bridge arm voltage value of the first battery pack, Rp represents the positive bridge arm resistance of the first battery pack, and Rn represents the negative bridge arm resistance of the first battery pack.

[0090] It should be noted that when only the standard vehicle battery pack ESS 1 exists and the portable battery pack ESS2 does not exist, V2 = 0V, which is equivalent to Figure 2 、 Figure 3 、 Figure 5 、 Figure 6 、 Figure 7 as well as Figure 8 Points B and C coincide, and the above Rx and Ry formulas still apply.

[0091] exist Figure 4 On the basis of how to obtain the first bridge arm resistance and the second bridge arm resistance, the embodiment of the present application also provides a possible implementation method, please refer to Figure 9 Before S102, the insulation test method of the pool system also includes: S101, which is described in detail as follows.

[0092] S101 , performing internal insulation detection on a first battery pack using a first battery management device and an insulation detection circuit to obtain a first bridge arm resistance and a second bridge arm resistance.

[0093] It should be understood that the first battery pack ESS 1 is a standard vehicle-mounted battery pack, and the BMS 1 it carries has full functions and can perform insulation testing independently to obtain the first bridge arm resistance and the second bridge arm resistance.

[0094] In a possible implementation, the second battery pack includes N portable battery packs, where N is greater than or equal to 1.

[0095] The N portable battery packs may be connected in series or in parallel, or some may be connected in series and some in parallel, which is not limited here.

[0096] See also Figure 10 , Figure 10 An insulation testing device for a battery system is provided in an embodiment of the present application. Optionally, the insulation testing device for a battery system is applied to the battery system described above.

[0097] The battery system includes a first battery pack and a second battery pack, the first battery pack and the second battery pack being connected in series. The first battery pack is equipped with a first battery management device and an insulation detection circuit, the insulation detection circuit including a first bridge arm and a second bridge arm. The first battery management device is configured to switch the first bridge arm and the second bridge arm between the on and off states, and the first battery management device is further configured to collect voltages across the first bridge arm and the second bridge arm.

[0098] The insulation testing device for a battery system includes a monitoring unit 201 and a processing unit 202 .

[0099] a monitoring unit 201 configured to obtain a first bridge arm voltage value and a second bridge arm voltage value, wherein the first bridge arm voltage value is a voltage value across the first bridge arm when the first bridge arm is turned on and the second bridge arm is turned off, and the second bridge arm voltage value is a voltage value across the second bridge arm when the second bridge arm is turned on and the first bridge arm is turned off;

[0100] The processing unit 202 is used to obtain the positive bridge arm insulation resistance value and the negative bridge arm insulation resistance value of the battery system based on the first bridge arm voltage value, the second bridge arm voltage value, the first bridge arm resistance, the second bridge arm resistance, the first battery pack voltage and the second battery pack voltage.

[0101] Optionally, the monitoring unit 201 may execute the above-mentioned S101 and S102, and the processing unit 202 may execute the above-mentioned S103.

[0102] It should be noted that the insulation testing device for a battery system provided in this embodiment can execute the method flow shown in the above method flow embodiment to achieve the corresponding technical effects. For the sake of brevity, any parts not mentioned in this embodiment can be referred to the corresponding contents in the above embodiment.

[0103] The present application also provides a storage medium storing computer instructions and programs that, when read and executed, execute the battery system insulation testing method of the above embodiment. The storage medium may include memory, flash memory, registers, or a combination thereof.

[0104] A battery system is provided below. Figure 1 、 Figure 2 as well as Figure 3 As shown in any of the preceding figures, the battery system includes a memory 11, a first battery pack equipped with a first battery management device, and a second battery pack, the first battery pack and the second battery pack being connected in series. The first battery management device 10 and the memory 11 are communicatively connected via a bus 12. The first battery management device 10 may be a CPU. The memory 11 is used to store one or more programs. When executed by the first battery management device 10, the insulation testing method of the battery system described in the above embodiment is performed.

[0105] Please refer to Figure 11 , Figure 11 This is one of the schematic diagrams of the battery system provided in an embodiment of the present application. The battery system includes a first battery management device 10, a memory 11, and a bus 12. The first battery management device 10 and the memory 11 are connected via the bus 12. The first battery management device 10 is configured to execute executable modules stored in the memory 11, such as computer programs.

[0106] The first battery management device 10 can be an integrated circuit chip with signal processing capabilities. During implementation, each step of the battery system insulation test method can be completed by the hardware integrated logic circuit or software instructions in the first battery management device 10. The above-mentioned first battery management device 10 can be a general battery management system, including a central processing unit (CPU), a network processor (NP), etc.; it can also be a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components.

[0107] The memory 11 may include a high-speed random access memory (RAM) and may also include a non-volatile memory.

[0108] The bus 12 may be an ISA (Industry Standard Architecture) bus, a PCI (Peripheral Component Interconnect) bus, or an EISA (Extended Industry Standard Architecture) bus. Figure 11 Only one bidirectional arrow is used in the figure, but it does not mean that there is only one bus 12 or one type of bus 12.

[0109] The memory 11 is used to store programs, such as a program for a battery system insulation test device. The battery system insulation test device includes at least one software functional module, which can be stored in the memory 11 in the form of software or firmware, or embedded in the battery system's operating system (OS). Upon receiving an execution instruction, the first battery management device 10 executes the program to implement the battery system insulation test method.

[0110] Possibly, the battery system provided in the embodiment of the present application further includes a communication interface 13. The communication interface 13 is connected to the first battery management device 10 via a bus. The communication interface 13 can be connected to the vehicle controller for communication and report the insulation test results.

[0111] In the embodiments provided in this application, it should be understood that the disclosed devices and methods can also be implemented in other ways. The device embodiments described above are merely schematic. For example, the flowcharts and block diagrams in the accompanying drawings show the possible architectures, functions and operations of the devices, methods and computer program products according to multiple embodiments of the present application. In this regard, each box in the flowchart or block diagram can represent a module, a program segment or a part of the code, and the module, program segment or a part of the code contains one or more executable instructions for implementing the specified logical functions. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in an order different from that marked in the accompanying drawings. For example, two consecutive boxes can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram and / or flowchart, and the combination of boxes in the block diagram and / or flowchart, can be implemented using a dedicated hardware-based system that performs the specified function or action, or can be implemented using a combination of dedicated hardware and computer instructions.

[0112] In addition, each functional module in each embodiment of the present application may exist independently, or two or more modules may be integrated to form an independent part.

[0113] If the functions are implemented in the form of software function modules and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0114] The above description is merely a preferred embodiment of the present application and is not intended to limit the present application. Various modifications and variations are possible for those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

[0115] It will be apparent to those skilled in the art that the present application is not limited to the details of the exemplary embodiments described above and that the present application can be implemented in other specific forms without departing from the spirit or essential characteristics of the present application. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the present application is defined by the appended claims, not the foregoing description, and all variations within the meaning and range of equivalents of the claims are intended to be included therein. Any reference sign in a claim should not be construed as limiting the claim to which it relates.

Claims

1. A method for insulation testing of a battery system, characterized in that: The battery system includes a first battery pack and a second battery pack, the first battery pack and the second battery pack being connected in series. The first battery pack is equipped with a first battery management device and an insulation detection circuit, the insulation detection circuit including a first bridge arm and a second bridge arm. The first battery management device is configured to switch the first bridge arm and the second bridge arm between the on and off states, and the first battery management device is further configured to collect voltages across the first bridge arm and the second bridge arm. The method comprises: Obtain a first bridge arm voltage value and a second bridge arm voltage value, wherein the first bridge arm voltage value is a voltage value across the first bridge arm when the first bridge arm is turned on and the second bridge arm is turned off, and the second bridge arm voltage value is a voltage value across the second bridge arm when the second bridge arm is turned on and the first bridge arm is turned off; Based on the first bridge arm voltage value, the second bridge arm voltage value, the first bridge arm resistance, the second bridge arm resistance, the first battery pack voltage and the second battery pack voltage, the positive bridge arm insulation resistance value and the negative bridge arm insulation resistance value of the battery system are obtained.

2. The insulation testing method of the battery system according to claim 1, wherein: The positive electrode of the first battery pack is connected to the negative electrode of the second battery pack, the first bridge arm resistance is the positive bridge arm resistance of the first battery pack, the first bridge arm voltage value is the positive bridge arm terminal voltage of the first battery pack, the second bridge arm resistance is the negative bridge arm resistance of the first battery pack, and the second bridge arm voltage value is the negative bridge arm terminal voltage of the first battery pack.

3. The insulation testing method of the battery system according to claim 2, wherein: Obtain the insulation resistance values ​​of the positive bridge arm and the negative bridge arm of the battery system according to the following formula; Among them, Rx represents the insulation resistance value of the positive bridge arm of the battery system, Ry represents the insulation resistance value of the negative bridge arm of the battery system, V1 represents the voltage of the first battery pack, V2 represents the voltage of the second battery pack, Vp represents the positive bridge arm voltage value of the first battery pack, Vn represents the negative bridge arm voltage value of the first battery pack, Rp represents the positive bridge arm resistance of the first battery pack, and Rn represents the negative bridge arm resistance of the first battery pack.

4. The insulation testing method of the battery system according to claim 1, wherein: The negative electrode of the first battery pack is connected to the positive electrode of the second battery pack, the first bridge arm resistance is the positive bridge arm resistance of the first battery pack, the first bridge arm voltage value is the positive bridge arm terminal voltage of the first battery pack, the second bridge arm resistance is the negative bridge arm resistance of the first battery pack, and the second bridge arm voltage value is the negative bridge arm terminal voltage of the first battery pack.

5. The insulation testing method of the battery system according to claim 4, wherein: Obtain the insulation resistance values ​​of the positive bridge arm and the negative bridge arm of the battery system according to the following formula; Among them, Rx represents the insulation resistance value of the positive bridge arm of the battery system, Ry represents the insulation resistance value of the negative bridge arm of the battery system, V1 represents the voltage of the first battery pack, V2 represents the voltage of the second battery pack, Vp represents the positive bridge arm voltage value of the first battery pack, Vn represents the negative bridge arm voltage value of the first battery pack, Rp represents the positive bridge arm resistance of the first battery pack, and Rn represents the negative bridge arm resistance of the first battery pack.

6. The insulation testing method of the battery system according to claim 1, wherein: Before obtaining the first bridge arm voltage value and the second bridge arm voltage value, the method further includes: An internal insulation test is performed on the first battery pack by using the first battery management device and the insulation detection circuit to obtain the first bridge arm resistance and the second bridge arm resistance.

7. The insulation testing method of a battery system according to claim 1, wherein: The second battery pack includes N portable battery packs, where N is greater than or equal to 1.

8. An insulation testing device for a battery system, characterized in that: The battery system includes a first battery pack and a second battery pack, the first battery pack and the second battery pack being connected in series. The first battery pack is equipped with a first battery management device and an insulation detection circuit, the insulation detection circuit including a first bridge arm and a second bridge arm. The first battery management device is configured to switch the first bridge arm and the second bridge arm between the on and off states, and the first battery management device is further configured to collect voltages across the first bridge arm and the second bridge arm. The device comprises: a monitoring unit, configured to obtain a first bridge arm voltage value and a second bridge arm voltage value, wherein the first bridge arm voltage value is a voltage value across the first bridge arm when the first bridge arm is turned on and the second bridge arm is turned off, and the second bridge arm voltage value is a voltage value across the second bridge arm when the second bridge arm is turned on and the first bridge arm is turned off; A processing unit is used to obtain a positive bridge arm insulation resistance value and a negative bridge arm insulation resistance value of the battery system based on the first bridge arm voltage value, the second bridge arm voltage value, the first bridge arm resistance, the second bridge arm resistance, the first battery pack voltage, and the second battery pack voltage.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by the first battery management device, the method according to any one of claims 1 to 7 is implemented.

10. A battery system, characterized in that: include: a memory, a first battery pack configured with a first battery management device, and a second battery pack, wherein the first battery pack and the second battery pack are connected in series; The memory is used to store one or more programs; When the one or more programs are executed by the first battery management device, the method according to any one of claims 1 to 7 is implemented.

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