Battery pack insulation detection circuit, insulation detection method and related device

Abstract

The embodiment of the invention provides a battery pack insulation detection circuit, an insulation detection method and a related device, and relates to the technical field of batteries, the insulation detection circuit comprises a control module, an insulation module, a switch module and a heating film; the control module, the insulation module, the switch module and the heating film are all connected with the positive electrode and the negative electrode of a battery module of the battery pack, and the switch module is further connected with a shell of the battery pack; and the control module is used for acquiring the insulation voltage of the battery module on the insulation module and determining whether the heating film is in insulation failure or not according to the insulation voltage. In this way, whether the heating film is in insulation failure or not can be rapidly and accurately detected.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a battery pack insulation detection circuit, an insulation detection method and related devices. Background Art

[0002] In the power battery system of new energy vehicles, heating films are often used to regulate the temperature of the battery pack so that the power battery pack is at a suitable operating temperature.

[0003] The heating film uses insulating materials to wrap the resistance wire or other heating core, and is powered by the battery pack for heating and temperature control. When the insulation of the heating film fails, it may cause the battery module to overlap with the shell, causing leakage. Therefore, during use, the heating film needs to be tested for insulation, but the accuracy of the current insulation test of the heating film is low. Summary of the invention

[0004] The embodiments of the present application provide a battery pack insulation detection circuit, an insulation detection method and related devices, which can effectively improve the accuracy of heating film insulation detection.

[0005] In a first aspect, an embodiment of the present application provides a battery pack insulation detection circuit, the insulation detection circuit comprising: a control module, an insulation module, a switch module and a heating film;

[0006] The control module, the insulation module, the switch module and the heating film are all connected to the positive and negative electrodes of the battery pack, and the switch module is also connected to the outer shell of the battery pack;

[0007] The control module is used to obtain the insulation voltage of the battery module to the insulation module, and determine whether the insulation of the heating film fails according to the insulation voltage.

[0008] In some embodiments, the switch module includes: a first switch, a second switch, and a third switch;

[0009] A first end of the first switch is connected to the positive electrode of the battery module, and a second end of the first switch is connected to the outer shell of the battery pack;

[0010] The first end of the second switch is connected to the positive electrode of the battery module through the heating film, and the second end of the second switch is connected to the outer shell of the battery pack;

[0011] The first end of the third switch is connected to the positive electrode of the battery module, and the second end of the third switch is connected to the negative electrode of the battery module through the insulation module.

[0012] In some embodiments, the insulation module includes a first resistor, a second resistor, and a third resistor;

[0013] The first resistor and the second resistor are connected in series between the positive electrode and the negative electrode of the battery module;

[0014] A first end of the third resistor is connected to a second end of the third switch, and a second end of the third resistor is connected to a midpoint between the first resistor and the second resistor.

[0015] In some embodiments, the switch module further includes: a fourth switch and a fifth switch;

[0016] The first end of the heating film is connected to the positive electrode of the battery module through the fourth switch, the second end of the heating film is connected to the negative electrode of the battery module through the fifth switch, and the third end of the heating film is connected to the first end of the second switch.

[0017] In some embodiments, the switch module further includes: a sixth switch and a seventh switch;

[0018] A first end of the sixth switch is connected to the positive electrode of the battery module, and a second end of the sixth switch is connected to an external electrical device;

[0019] A first end of the seventh switch is connected to the negative electrode of the battery module, and a second end of the seventh switch is connected to an external electrical device.

[0020] In a second aspect, an embodiment of the present application provides a battery pack insulation detection method, which is applied to the insulation detection circuit as described in any one of the first aspects, and the method includes:

[0021] When performing insulation detection, obtaining an insulation detection strategy; the insulation detection strategy is used to indicate the on-off state of the switch in the insulation detection circuit;

[0022] Controlling the corresponding switch to be turned on or off according to the insulation detection strategy, and obtaining the positive electrode-to-shell voltage of the battery pack and the negative electrode-to-shell voltage of the battery module;

[0023] The battery pack is subjected to insulation testing according to the positive electrode-to-shell voltage and the negative electrode-to-shell voltage.

[0024] In some embodiments, controlling the corresponding switch to be turned on or off according to the insulation detection strategy and obtaining the positive electrode-to-shell voltage of the battery pack and the negative electrode-to-shell voltage of the battery module include:

[0025] Controlling the sixth switch, the seventh switch and the first switch in the insulation detection circuit to be turned on, obtaining the first pair-shell voltage of the positive electrode and the first pair-shell voltage of the negative electrode, and then controlling the third switch to be turned on, obtaining the second pair-shell voltage of the positive electrode and the second pair-shell voltage of the negative electrode;

[0026] The sixth switch, the seventh switch, and the second switch are controlled to be turned on to obtain the third pair-shell voltage of the positive electrode and the third pair-shell voltage of the negative electrode, and then the third switch is controlled to be turned on to obtain the fourth pair-shell voltage of the positive electrode and the fourth pair-shell voltage of the negative electrode.

[0027] In some embodiments, the performing insulation detection on the battery pack according to the positive electrode-to-shell voltage and the negative electrode-to-shell voltage includes:

[0028] Obtaining a first insulation resistance of the battery pack according to the first pair-of-shell voltage of the positive electrode and the first pair-of-shell voltage of the negative electrode, and the second pair-of-shell voltage of the positive electrode and the second pair-of-shell voltage of the negative electrode;

[0029] Obtaining a second insulation resistance of the battery pack according to the third shell-to-shell voltage of the positive electrode and the third shell-to-shell voltage of the negative electrode, and the fourth shell-to-shell voltage of the positive electrode and the fourth shell-to-shell voltage of the negative electrode;

[0030] An insulation test is performed on the battery pack according to the first insulation resistance and the second insulation resistance.

[0031] In some embodiments, the performing insulation detection on the battery pack according to the first insulation resistance and the second insulation resistance includes:

[0032] If the first insulation resistance is less than or equal to a preset resistance, and the second insulation resistance is less than or equal to the preset resistance, it is determined that the insulation of the heating film in the battery pack fails;

[0033] If the first insulation resistance is less than or equal to a preset resistance, and the second insulation resistance is greater than the preset resistance, it is determined that the insulation of the heating film has not failed, and the insulation of other parts of the battery pack has failed;

[0034] If the first insulation resistance is greater than a preset resistance and the second insulation resistance is less than or equal to the preset resistance, it is determined that the insulation of the heating film in the battery pack fails;

[0035] If the first insulation resistance is greater than a preset resistance, and the second insulation resistance is greater than the preset resistance, it is determined that the battery pack insulation has not failed.

[0036] In a third aspect, the present application provides an electronic device, including: a memory and a processor;

[0037] The memory is used to store computer instructions; the processor is used to execute the computer instructions stored in the memory to implement any method in the second aspect.

[0038] In a fourth aspect, the present application provides a computer-readable storage medium having a computer program stored thereon, and the computer program is executed by a processor to implement any one of the methods in the second aspect.

[0039] In a fifth aspect, the present application provides a computer program product, comprising a computer program, which implements any method in the second aspect when executed by a processor.

[0040] In a sixth aspect, an embodiment of the present application provides a vehicle, in which the insulation detection circuit as described in any one of the first aspects is provided.

[0041] The battery pack insulation detection circuit, insulation detection method and related device provided in the embodiment of the present application, the insulation detection circuit includes: a control module, an insulation module, a switch module and a heating film; the control module, the insulation module, the switch module and the heating film are all connected to the positive and negative electrodes of the battery module of the battery pack, and the switch module is also connected to the outer shell of the battery pack; the control module is used to obtain the insulation voltage of the battery module to the insulation module, and determine whether the insulation of the heating film fails according to the insulation voltage. Through the above circuit, it is possible to quickly and accurately detect whether the insulation of the heating film fails, reducing the safety risks caused by the insulation failure of the heating film. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 A schematic diagram of the structure of a battery pack provided in an embodiment of the present application;

[0043] Figure 2 A schematic diagram of the structure of an insulation detection circuit provided in an embodiment of the present application Figure 1 ;

[0044] Figure 3 A schematic diagram of the structure of an insulation detection circuit provided in an embodiment of the present application Figure 2 ;

[0045] Figure 4 A schematic diagram of the structure of an insulation detection circuit provided in an embodiment of the present application Figure 3 ;

[0046] Figure 5 An insulation detection logic diagram provided in an embodiment of the present application;

[0047] Figure 6 A schematic diagram of a flow chart of an insulation detection method provided in an embodiment of the present application;

[0048] Figure 7 A schematic diagram of the structure of an insulation detection device provided in an embodiment of the present application;

[0049] Figure 8A schematic diagram of the structure of an electronic device provided in an embodiment of the present application;

[0050] Fig. 9 A schematic diagram of the structure of a vehicle provided in an embodiment of the present application. DETAILED DESCRIPTION

[0051] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0052] In the embodiments of the present application, words such as "first" and "second" are used to distinguish the same or similar items with substantially the same functions and effects, and do not limit their order. Those skilled in the art can understand that words such as "first" and "second" do not limit the quantity and execution order, and words such as "first" and "second" do not necessarily limit them to be different.

[0053] It should be noted that in the embodiments of the present application, words such as "exemplary" or "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "exemplary" or "for example" in the present application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary" or "for example" is intended to present related concepts in a specific way.

[0054] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0055] In the power battery system of new energy vehicles, heating films are often used to regulate the temperature of the battery pack so that the power battery pack is at a suitable operating temperature.

[0056] The heating film uses insulating material to wrap the resistance wire or other heating core, and is powered by the battery pack for heating and temperature control. When the insulation of the heating film fails, it may cause the battery module to overlap with the shell, causing leakage.

[0057] In the related art, insulation testing of the heating film is usually performed before the battery pack is equipped with the heating film, or the insulation of the heating film is tested by an insulation withstand voltage test before the whole vehicle is assembled to obtain its insulation resistance, or the battery pack is tested in real time using the principle of the double probe method.

[0058] However, when the vehicle is working, the use of the voltage resistance test method may cause the battery pack to lose control and endanger the safety of the passengers; when the insulation between the heating film and the battery cell of the battery pack fails due to foreign matter, if the battery cell and the heating film are not overlapped with the battery pack shell, the double probe method cannot be used to measure whether the insulation of the heating film has failed.

[0059] In view of this, an embodiment of the present application provides a battery pack insulation detection circuit, an insulation detection method and related devices, which perform insulation detection on the battery pack through the voltage of the insulation resistance in the insulation detection circuit, and can quickly and accurately detect whether the insulation of the heating film fails while ensuring the safety of the passengers.

[0060] The following specific embodiments are used to describe in detail the technical solution of the present application and how the technical solution of the present application solves the above technical problems. The following specific embodiments can be implemented independently or in combination with each other, and the same or similar concepts or processes may not be described in detail in some embodiments.

[0061] Figure 1 A schematic diagram of a battery pack structure provided in an embodiment of the present application is shown in FIG. Figure 1 As shown, the battery pack includes: a shell, a battery module, a heating film, and a control module.

[0062] The heating film is arranged above the battery module and connected to the positive and negative electrodes of the battery module. The heating film is powered by the battery module so that the heating film heats the battery pack.

[0063] The control module is arranged at the head of the battery module and connected to the battery module to control the battery module, for example, to control the battery module to charge and discharge, etc. The control module may be a battery management system (BMS).

[0064] Next, the insulation detection circuit provided in the embodiment of the present application is described.

[0065] Figure 2 A schematic diagram of the structure of an insulation detection circuit provided in an embodiment of the present application Figure 1 ,like Figure 2 As shown, the insulation detection circuit includes: a control module, an insulation module, a switch module and a heating film.

[0066] The control module, the insulation module, the switch module and the heating film are all connected to the positive and negative electrodes of the battery pack, and the switch module is also connected to the outer shell of the battery pack. The positive and negative electrodes of the battery pack may refer to the positive and negative electrodes of the battery modules in the battery pack.

[0067] In some embodiments, the switch module includes a plurality of switches, which are respectively arranged in the insulation detection circuit to realize the switching on or off of various components or modules in the insulation detection circuit, for example, the insulation module, the heating film, etc.

[0068] The control module is used to control the switch in the switch module to be turned on or off, so as to obtain the insulation voltage of the battery module on the insulation module (also known as the insulation voltage of the battery module to the outer casing) from the insulation module, and determine whether the insulation of the heating film fails based on the insulation voltage.

[0069] In some embodiments, the control module may be a control module in the battery pack, or other circuits with control functions, which is not limited in the embodiments of the present application.

[0070] In some embodiments, Figure 3 As shown, the switch module includes a first switch S1, a second switch S2 and a third switch S3.

[0071] The first end of the first switch S1 is connected to the positive electrode of the battery module, and the second end of the first switch S1 is connected to the outer shell of the battery pack.

[0072] The first end of the second switch S2 is connected to the positive electrode of the battery module through the heating film, and the second end of the second switch S2 is connected to the outer shell of the battery pack. It should be understood that the first end of the second switch S2 is connected to the insulating layer of the heating film.

[0073] A first end of the third switch S3 is connected to the positive electrode of the battery module, and a second end of the third switch S3 is connected to the negative electrode of the battery module through the insulation module.

[0074] The switch included in the above-mentioned switch module can be any switch tube that can be turned on or off based on control, for example, a relay, a contactor, an insulated gate bipolar transistor (IGBT), or a metal-oxide-semiconductor field effect transistor (MOS) or a triode, or a thyristor. The first switch and the second switch can be different or the same, for example, the first switch uses a relay and the second switch uses a triode, or the first switch and the second switch are both relays, which is not limited in the embodiments of the present application.

[0075] In a specific implementation, the control module can control the first switch to be turned on to obtain the first voltage of the positive and negative electrodes of the battery module to the insulating module, and then control the third switch to be turned on to obtain the second voltage of the positive and negative electrodes of the battery module to the insulating module. Secondly, based on the first voltage and the second voltage, the first insulation resistance of the battery system is obtained, and the first insulation resistance is used to determine whether there is an insulation failure of the battery pack to the outside. On this basis, the control module can also control the second switch to be turned on to obtain the third voltage of the positive and negative electrodes of the battery module to the insulating module. And, control the third switch to be turned on to obtain the fourth voltage of the positive and negative electrodes of the battery module to the insulating module, and determine the second insulation resistance of the battery pack based on the third and fourth voltages. Finally, based on the second insulation resistance, determine whether there is an insulation failure in the heating film or the remaining structures of the battery pack other than the heating film.

[0076] Exemplarily, if the first insulation resistance is greater than the minimum insulation resistance of the battery pack, it can be determined that the insulation of the battery pack to the outside has not failed, and if the second insulation resistance is less than the minimum insulation resistance of the battery pack, it can be determined that the insulation of the heating film has failed. If both the first insulation resistance and the second insulation resistance are greater than the minimum insulation resistance of the battery pack, it can be determined that the insulation of the battery pack has not failed. If the first insulation resistance is greater than the minimum insulation resistance of the battery pack, and the second insulation resistance is less than the minimum insulation resistance of the battery pack, it can be determined that the insulation of the heating film of the battery pack has failed. If both the first insulation resistance and the second insulation resistance are less than the minimum insulation resistance of the battery pack, it can be determined that the insulation of the heating film of the battery pack has failed. If the first insulation resistance is less than the minimum insulation resistance of the battery pack, and the second insulation resistance is greater than the minimum insulation resistance of the battery pack, it can be determined that the insulation of the heating film of the battery pack has not failed, and the insulation of the battery pack other than the heating film has failed. Based on the above structure and description, the insulation detection circuit provided in the embodiment of the present application increases the connection structure between the switch module and the battery pack shell, controls the corresponding switch to be turned on or off, determines the insulation resistance of the battery based on the obtained battery module-shell voltage, and determines whether the insulation of the heating film has failed based on the insulation resistance. This allows for rapid and accurate insulation detection of the heating film, thus avoiding safety issues with the battery pack caused by abnormal insulation of the heating film.

[0077] Combine the following Figure 4 The insulation detection circuit provided in the embodiment of the present application is further described.

[0078] Figure 4 A schematic diagram of the structure of the insulation detection circuit provided in the embodiment of the present application Figure 3 ,like Figure 4 As shown, the insulation module includes a first resistor R P , the second resistor R N and a third resistor R1.

[0079] The first resistor R P The second resistor R N The first end of the third resistor R1 is connected to the second end of the third switch S3, and the second end of the third resistor R2 is connected to the first resistor R P and the midpoint of the second resistor.

[0080] In some embodiments, the first resistor R P is the resistance of the positive electrode of the battery module to the housing, and the second resistor R N is the resistance between the negative electrode of the battery module and the shell, and R1 is a standard resistor with a preset resistance value, for example, the resistance value can be 1 ohm, 10 ohms, etc.

[0081] In some embodiments, Figure 4 As shown, the switch module further includes a fourth switch S4 and a fifth switch S5 , and the heating film B includes a first end 1 , a second end 2 and a third end 3 .

[0082] The first end 1 of the heating film B is connected to the positive electrode of the battery module A through the fourth switch S4, and the second end 2 of the heating film B is connected to the negative electrode of the battery module A through the fifth switch S5. The third end of the heating film B is connected to the first end of the second switch S2, that is, the third end of the heating film B is connected to the outer shell of the battery pack through the second switch S2, the fourth switch S4 is the positive switch of the heating film, and the fifth switch S5 is the negative switch of the heating film.

[0083] When the vehicle is working, the control module can control the fourth switch S4 and the fifth switch S5 to be turned on, and supply power to the heating film to increase the temperature, thereby heating the battery pack.

[0084] In some embodiments, Figure 4 As shown, the switch module further includes a sixth switch S6 and a seventh switch S7.

[0085] The first end of the sixth switch S6 is connected to the positive electrode of the battery module A, and the second end of the sixth switch S6 is connected to an external power device; the first end of the seventh switch S7 is connected to the negative electrode of the battery module A, and the second end of the seventh switch is connected to an external power device. That is, the sixth switch S6 is the total positive switch of the battery module A, and the seventh switch S7 is the total negative switch of the battery module A.

[0086] In some embodiments, each switch and resistor in the insulation detection circuit can be set in the distribution box of the battery pack, and the control module can also be set in the distribution box of the battery pack, wherein the distribution box of the battery pack can be set in a position such as Figure 1 Shown is the location of the control module.

[0087] It should be understood that when each of the switches adopts relays, the first switch can be called a total positive to shell line relay, the second switch can be called a heating film to shell line relay, the third switch can be called a standard resistance relay, the fourth switch and the fifth switch can be called heating film relays, the sixth switch can be called a total positive relay, and the seventh switch can be called a total negative relay.

[0088] When the insulation detection circuit is working, the control module can control the sixth switch, the seventh switch and the first switch to be turned on, and obtain the insulation detection circuit of the battery module A at the first resistor R P The first voltage on the battery module (the voltage of the positive electrode to the shell) and the second resistor RN The first voltage on the negative electrode of the battery module (the voltage of the battery module negative electrode to the shell), thereby controlling the third switch to be turned on, and obtaining the battery module A at the first resistor R P The second voltage on the battery module (the voltage of the positive electrode to the shell of the battery module) and the second resistor R N The second voltage on the battery module (the voltage of the negative electrode to the shell of the battery module) is calculated by the bridge method based on the above two sets of voltages. The first insulation resistance of the battery pack (also known as the insulation resistance of the entire battery pack, R i1 ), and judging whether the battery pack is insulated from the outside according to the relationship between the first insulation resistance and a preset resistance (also called the minimum insulation resistance R0), wherein the preset resistance is the minimum insulation resistance of the battery pack.

[0089] Further, the control module can control the first switch to be opened, the second switch to be closed, and the third switch to be opened, so as to obtain the battery module A at the first resistor R P The third voltage on the battery module (the voltage of the positive electrode to the shell) and the second resistor R N The third voltage on the negative electrode of the battery module (the voltage of the battery module negative electrode to the shell), thereby controlling the third switch to be turned on, and obtaining the battery module A at the first resistor R P The fourth voltage (battery module positive electrode to shell voltage) on N The fourth voltage on the battery module (the battery module negative electrode to shell voltage), based on the above two sets of voltages, the second insulation resistance of the battery pack (also known as the battery pack internal insulation resistance, R i2 ), and judge whether the interior of the battery pack is partially insulated (for example, whether the heating film is insulated, and whether other parts of the battery pack are insulated) according to the relationship between the second insulation resistance and the preset resistance.

[0090] Exemplarily, if the first insulation resistance is greater than the minimum insulation resistance of the battery pack, it can be determined that the insulation of the battery pack to the outside has not failed, and if the second insulation resistance is less than the minimum insulation resistance of the battery pack, it can be determined that the insulation of the heating film has failed. If both the first insulation resistance and the second insulation resistance are greater than the minimum insulation resistance of the battery pack, it can be determined that the insulation of the battery pack has not failed. If the first insulation resistance is greater than the minimum insulation resistance of the battery pack, and the second insulation resistance is less than the minimum insulation resistance of the battery pack, it can be determined that the insulation of the heating film of the battery pack has failed. If the first insulation resistance and the second insulation resistance are both less than the minimum insulation resistance of the battery pack, it can be determined that the insulation of the heating film of the battery pack has failed. If the first insulation resistance is less than the minimum insulation resistance of the battery pack, and the second insulation resistance is greater than the minimum insulation resistance of the battery pack, it can be determined that the insulation of the heating film of the battery pack has not failed, and the insulation of the battery pack other than the heating film has failed. Based on the above structure and description, the insulation detection circuit ( Figure 4 ) and detection logic diagram ( Figure 5 ), by adding a connection structure between a switch module and a battery pack shell, by controlling the corresponding switch to be turned on or off, the insulation resistance of the battery is determined based on the obtained battery module-to-shell voltage, and based on the insulation resistance, whether the insulation of the heating film has failed is determined. The insulation detection of the heating film can be achieved quickly and accurately, thus avoiding safety problems of the battery pack caused by abnormal insulation of the heating film.

[0091] To sum up, the insulation detection circuit provided in the embodiment of the present application can not only detect the insulation resistance of the entire battery pack, but also detect whether the insulation of the heating film inside the battery pack has failed, thereby reducing the probability of safety accidents caused by insulation failure of the battery pack or the heating film.

[0092] On the basis of the above embodiments, an embodiment of the present application further provides an insulation detection method for a battery pack, and the insulation detection method performs insulation detection on the battery pack through the insulation detection circuit described in any of the above embodiments.

[0093] Figure 6 A schematic diagram of a flow chart of a battery pack insulation detection method provided in an embodiment of the present application, such as Figure 6 As shown, including:

[0094] S601. When performing insulation detection, obtain an insulation detection strategy; the insulation detection strategy is used to indicate the on-off state of a switch in the insulation detection circuit.

[0095] The execution subject of the embodiment of the present application may be the control module in the insulation detection circuit described in the above embodiment.

[0096] In some embodiments, the control module may perform insulation detection on the battery pack when the vehicle is powered on, when the vehicle is charging, or when the vehicle is driving. The present application embodiment does not limit the timing of performing insulation detection. In other words, the control module may perform insulation detection on the battery pack in real time.

[0097] In some embodiments, the insulation detection strategy may be pre-stored inside the control module, or stored in an external memory. When the control module determines to perform insulation detection, it may read the insulation detection strategy from the internal or external memory.

[0098] S602, controlling the corresponding switch to be turned on or off according to the insulation detection strategy, and obtaining the positive electrode-to-shell voltage of the battery module of the battery pack and the negative electrode-to-shell voltage of the battery module.

[0099] Exemplarily, the insulation detection strategy may be as follows:

[0100] The first step: controlling the sixth switch, the seventh switch and the first switch to be turned on, and then controlling the third switch to be turned on.

[0101] The second step is to control the sixth switch, the seventh switch and the second switch to be turned on, and then control the third switch to be turned on.

[0102] When the control module obtains the insulation detection strategy, it starts to execute the detection strategy and obtains the corresponding shell voltage under the strategy.

[0103] Exemplarily, the first step is performed to control the sixth switch, the seventh switch, and the first switch to be turned on, to obtain the first shell-to-shell voltage of the positive electrode and the first shell-to-shell voltage of the negative electrode, and then to control the third switch to be turned on, to obtain the second shell-to-shell voltage of the positive electrode and the second shell-to-shell voltage of the negative electrode. The corresponding shell-to-shell voltages can be determined based on the voltage signals of the switches.

[0104] For example, the first pair of shell voltages of the positive electrode obtained is represented as U1, the second pair of shell voltages of the positive electrode obtained is represented as U11, the first pair of shell voltages of the negative electrode obtained is represented as U2, and the second pair of shell voltages of the negative electrode obtained is represented as U22.

[0105] Exemplarily, the second step is performed to control the sixth switch, the seventh switch and the second switch to be turned on, obtain the third pair of shell voltages of the positive electrode and the third pair of shell voltages of the negative electrode, and then control the third switch to be turned on to obtain the fourth pair of shell voltages of the positive electrode and the fourth pair of shell voltages of the negative electrode.

[0106] For example, the third pair-shell voltage of the positive electrode is represented as U3, the fourth pair-shell voltage of the positive electrode is represented as U33, the fourth pair-shell voltage of the negative electrode is represented as U4, and the second pair-shell voltage of the negative electrode is represented as U44.

[0107] S603: Perform insulation testing on the battery pack according to the positive electrode-to-shell voltage and the negative electrode-to-shell voltage.

[0108] In some embodiments, when the control module obtains the voltage between the positive and negative electrodes and the shell in different states, the insulation detection of the battery pack can be performed as shown below.

[0109] Exemplarily, the first insulation resistance of the battery pack is obtained according to the first pair-shell voltage of the positive electrode and the first pair-shell voltage of the negative electrode, and the second pair-shell voltage of the positive electrode and the second pair-shell voltage of the negative electrode.

[0110] In some embodiments, the first insulation resistance may satisfy the following formula:

[0111]

[0112] Among them, R P is the first resistor, R N is the second resistor, R1 is the third resistor, and their resistance values ​​are known.

[0113] Substituting the obtained U1, U11, U2, and U22 into the above formula for joint solution, we can get R P and R N The smaller value among them is taken as the first insulation resistance.

[0114] Exemplarily, the second insulation resistance of the battery pack is obtained according to the third shell-to-shell voltage of the positive electrode and the third shell-to-shell voltage of the negative electrode, and the fourth shell-to-shell voltage of the positive electrode and the fourth shell-to-shell voltage of the negative electrode.

[0115] The second insulation resistance can satisfy the following formula:

[0116]

[0117] Substituting the obtained U3, U33, U4, and U44 into the above formula for simultaneous solution, we can get R P and R N The smaller of the two values ​​is taken as the second insulation resistance.

[0118] Exemplarily, the battery pack is subjected to insulation testing based on the first insulation resistance and the second insulation resistance.

[0119] If the first insulation resistance is less than or equal to the minimum resistance R0 (preset resistance) of the battery pack, it is determined that the insulation of the battery pack to the outside has failed, and it is necessary to determine whether the insulation failure is caused by the heating film or the insulation failure is caused by other parts of the battery pack based on the second insulation resistance. In this case, if the second insulation resistance is less than or equal to the minimum resistance R0, it is determined that the insulation failure is caused by the heating film, and if the second insulation resistance is greater than the minimum resistance R0, it is determined that the insulation failure is caused by other parts of the battery pack. That is, if the first insulation resistance is less than or equal to the preset resistance, and the second insulation resistance is less than or equal to the preset resistance, it is determined that the insulation of the heating film in the battery pack has failed; if the first insulation resistance is less than or equal to the preset resistance, and the second insulation resistance is greater than the preset resistance, it is determined that the insulation of the heating film has not failed, and the insulation of other parts of the battery pack has failed.

[0120] If the first insulation resistance is greater than the minimum resistance R0 (preset resistance) of the battery pack, it is determined that the insulation of the battery pack to the outside has not failed. In this case, whether the insulation of the heating film has failed can be determined based on the second insulation resistance. If the second insulation resistance is less than or equal to the minimum resistance R0, it is determined that the insulation of the heating film has failed. If the second insulation resistance is greater than the minimum resistance R0, it is determined that there is no insulation failure inside or outside the battery pack. That is, if the first insulation resistance is greater than the preset resistance, and the second insulation resistance is less than or equal to the preset resistance, it is determined that the insulation of the heating film in the battery pack has failed; if the first insulation resistance is greater than the preset resistance, and the second insulation resistance is greater than the preset resistance, it is determined that the insulation of the battery pack has not failed.

[0121] Based on the above embodiments, the embodiments of the present application also provide a battery pack insulation detection device.

[0122] Figure 7 A schematic diagram of the structure of a battery pack insulation detection device 60 provided in an embodiment of the present application is shown in FIG. Figure 7 As shown, including:

[0123] The acquisition module 701 is used to acquire an insulation detection strategy when performing insulation detection; the insulation detection strategy is used to indicate the on-off state of the switch in the insulation detection circuit.

[0124] The processing module 702 is used to control the corresponding switch to be turned on or off according to the insulation detection strategy, and obtain the positive electrode-to-shell voltage of the battery module of the battery pack and the negative electrode-to-shell voltage of the battery module.

[0125] The detection module 703 is used to perform insulation detection on the battery pack according to the positive electrode-to-shell voltage and the negative electrode-to-shell voltage.

[0126] In some embodiments, the processing module 702 is also used to control the sixth switch, the seventh switch and the first switch in the insulation detection circuit to be turned on, to obtain the first pair of shell voltages of the positive electrode and the first pair of shell voltages of the negative electrode, and then control the third switch to be turned on, to obtain the second pair of shell voltages of the positive electrode and the second pair of shell voltages of the negative electrode; control the sixth switch, the seventh switch and the second switch to be turned on, to obtain the third pair of shell voltages of the positive electrode and the third pair of shell voltages of the negative electrode, and then control the third switch to be turned on, to obtain the fourth pair of shell voltages of the positive electrode and the fourth pair of shell voltages of the negative electrode.

[0127] In some embodiments, the detection module 703 is further used to obtain a first insulation resistance of the battery pack based on the first pair-shell voltage of the positive electrode and the first pair-shell voltage of the negative electrode, as well as the second pair-shell voltage of the positive electrode and the second pair-shell voltage of the negative electrode; obtain a second insulation resistance of the battery pack based on the third pair-shell voltage of the positive electrode and the third pair-shell voltage of the negative electrode, as well as the fourth pair-shell voltage of the positive electrode and the fourth pair-shell voltage of the negative electrode; and perform insulation detection on the battery pack based on the first insulation resistance and the second insulation resistance.

[0128] In some embodiments, the detection module 703 is further used to determine that the insulation of the heating film in the battery pack has failed if the first insulation resistance is less than or equal to a preset resistance and the second insulation resistance is less than or equal to the preset resistance; if the first insulation resistance is less than or equal to the preset resistance and the second insulation resistance is greater than the preset resistance, it is determined that the insulation of the heating film has not failed, but the insulation of other parts of the battery pack has failed; if the first insulation resistance is greater than the preset resistance and the second insulation resistance is less than or equal to the preset resistance, it is determined that the insulation of the heating film in the battery pack has failed;

[0129] If the first insulation resistance is greater than a preset resistance, and the second insulation resistance is greater than the preset resistance, it is determined that the battery pack insulation has not failed.

[0130] The battery pack insulation detection device provided in the embodiment of the present application can execute the battery pack insulation detection method provided in any of the above embodiments, and its principles and technical effects are similar, which will not be repeated here.

[0131] It should be noted that it should be understood that the division of the various modules of the above device is only a division of logical functions. In actual implementation, they can be fully or partially integrated into one physical entity, or they can be physically separated. And these modules can all be implemented in the form of software called by processing elements; they can also be all implemented in the form of hardware; some modules can also be implemented in the form of software called by processing elements, and some modules can be implemented in the form of hardware. Each module can be a separately established processing element, or it can be integrated in a chip of the above device. In addition, it can also be stored in the memory of the above device in the form of program code, and called and executed by a processing element of the above device. The functions of each module. In addition, all or part of these modules can be integrated together, or they can be implemented independently. The processing element here can be an integrated circuit with signal processing capabilities. In the implementation process, each step of the above method or each module above can be completed by an integrated logic circuit of hardware in the processor element or instructions in the form of software.

[0132] An embodiment of the present application also provides an electronic device, which may be the control module described in any of the above embodiments.

[0133] Figure 8 A schematic diagram of the structure of an electronic device 80 provided in an embodiment of the present application is shown in FIG. Figure 8 As shown, it includes: a transceiver 801, a processor 802, and a memory 803.

[0134] The processor 802 executes the computer execution instructions stored in the memory, so that the processor 802 executes the scheme in the above embodiment. The processor 802 can be a general-purpose processor, including a central processing unit CPU, a network processor (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 gates or transistor logic devices, discrete hardware components.

[0135] The memory 803 is connected to the processor 802 via a system bus and implements communication therebetween. The memory 803 is used to store computer program instructions.

[0136] The transceiver 801 can receive voltage signals and send control instructions.

[0137] Optionally, the electronic device 80 may further include a communication interface, so that it can communicate and interact with an external or internal device through the communication interface, and the external device may be, for example, a client (e.g., a mobile phone, a tablet). In a specific implementation, if the communication interface, the memory 803, and the processor 802 are implemented independently, the communication interface, the memory 803, and the processor 802 may be interconnected through a bus and communicate with each other.

[0138] The system bus can be a peripheral component interconnect (PCI) bus or an extended industry standard architecture (EISA) bus, etc. The system bus can be divided into an address bus, a data bus, a control bus, etc. For ease of representation, only one thick line is used in the figure, but it does not mean that there is only one bus or one type of bus. The transceiver is used to realize the communication between the database access device and other computers (such as clients, read-write libraries, and read-only libraries). The memory may include random access memory (RAM) and may also include non-volatile memory.

[0139] Optionally, in a specific implementation, if the communication interface, the memory 803 and the processor 802 are integrated on a chip, the communication interface, the memory 803 and the processor 802 can complete communication through an internal interface.

[0140] An embodiment of the present application also provides a vehicle.

[0141] Fig. 9 A structural diagram of a vehicle 90 is provided for an embodiment of the present application, such as Fig. 9 As shown, the vehicle is provided with the insulation detection circuit described in any of the above embodiments.

[0142] A computer-readable storage medium is also provided in an embodiment of the present application, on which a computer program is stored. When the computer program is executed by a processor, the technical solution of the above-mentioned battery pack insulation detection method embodiment is implemented. The implementation principle and technical effect are similar and will not be repeated here.

[0143] In one possible implementation, a computer-readable medium may include a random access memory (RAM), a read-only memory (ROM), a compact disc read-only memory (CD-ROM) or other optical disk storage, a magnetic disk storage or other magnetic storage device, or any other medium that is intended to carry or store the required program code in the form of instructions or data structures and can be accessed by a computer. Moreover, any connection is appropriately referred to as a computer-readable medium. For example, if the software is transmitted from a website, server or other remote source using a coaxial cable, a fiber optic cable, a twisted pair, a digital subscriber line (DSL) or wireless technologies such as infrared, radio and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL or wireless technologies such as infrared, radio and microwave are included in the definition of the medium. Disks and optical disks as used herein include optical disks, laser disks, optical disks, digital versatile disks (DVDs), floppy disks and Blu-ray disks, where disks usually reproduce data magnetically, while optical disks reproduce data optically using lasers. Combinations of the above should also be included within the scope of computer-readable media.

[0144] A computer program product is also provided in an embodiment of the present application, including a computer program. When the computer program is executed by a processor, the technical solution of the above-mentioned battery pack insulation detection method embodiment is implemented. The implementation principle and technical effect are similar and will not be repeated here.

[0145] In the specific implementation of the above-mentioned terminal device or server, it should be understood that the processor can be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), etc. The general-purpose processor can be a microprocessor or the processor can be any conventional processor, etc. The steps of the method disclosed in the embodiments of the present application can be directly embodied as being executed by a hardware processor, or can be executed by a combination of hardware and software modules in the processor.

[0146] Those skilled in the art will appreciate that all or part of the steps of any of the above method embodiments may be completed by hardware associated with program instructions. The aforementioned program may be stored in a computer-readable storage medium, and when the program is executed, all or part of the steps of the above method embodiments are executed.

[0147] If the technical solution of the present application is implemented in the form of software and sold or used as a product, it can be stored in a computer-readable storage medium. Based on such an understanding, all or part of the technical solution of the present application can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a computer program or several instructions. The computer software product enables a computer device (which can be a personal computer, a server, a network device, or a similar electronic device) to perform all or part of the steps of the method described in the embodiment of the present application.

[0148] It should be noted that, for the aforementioned method embodiments, for the sake of simplicity, they are all expressed as a series of action combinations, but those skilled in the art should be aware that the present application is not limited by the described order of actions, because according to the present application, certain steps can be performed in other orders or simultaneously. Secondly, those skilled in the art should also be aware that the embodiments described in the specification are all optional embodiments, and the actions and modules involved are not necessarily required by the present application.

[0149] It should be further noted that, although the various steps in the flowchart are displayed in sequence according to the indication of the arrows, these steps are not necessarily executed in sequence in the order indicated by the arrows. Unless there is a clear description in this article, the execution of these steps is not strictly limited in order, and these steps can be executed in other orders. Moreover, at least a portion of the steps in the flowchart may include multiple sub-steps or multiple stages, and these sub-steps or stages are not necessarily executed at the same time, but can be executed at different times, and the execution order of these sub-steps or stages is not necessarily to be carried out in sequence, but can be executed in turn or alternately with other steps or at least a portion of the sub-steps or stages of other steps.

[0150] It should be understood that the above-mentioned device embodiments are only illustrative, and the device of the present application can also be implemented in other ways. For example, the division of units / modules in the above-mentioned embodiments is only a logical function division, and there may be other division methods in actual implementation. For example, multiple units, modules or components can be combined, or can be integrated into another system, or some features can be ignored or not executed.

[0151] In addition, unless otherwise specified, each functional unit / module in each embodiment of the present application may be integrated into one unit / module, each unit / module may exist physically separately, or two or more units / modules may be integrated together. The above-mentioned integrated unit / module may be implemented in the form of hardware or in the form of a software program module.

[0152] If the integrated unit / module is implemented in the form of hardware, the hardware may be a digital circuit, an analog circuit, etc. The physical implementation of the hardware structure includes but is not limited to transistors, memristors, etc. If not specifically stated, the processor may be any appropriate hardware processor, such as a CPU, a GPU, an FPGA, a DSP, an ASIC, etc. If not specifically stated, the storage unit may be any appropriate magnetic storage medium or magneto-optical storage medium, such as a resistive random access memory RRAM (Resistive Random Access Memory), a dynamic random access memory DRAM (Dynamic Random Access Memory), a static random access memory SRAM (Static Random-Access Memory), an enhanced dynamic random access memory EDRAM (Enhanced Dynamic Random Access Memory), a high-bandwidth memory HBM (High-Bandwidth Memory), a hybrid memory cube HMC (Hybrid Memory Cube), etc.

[0153] If the integrated unit / module is implemented in the form of a software program module and sold or used as an independent product, it can be stored in a computer-readable memory. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art or all or part of the technical solution, can be embodied in the form of a software product, which is stored in a memory and includes several instructions for a computer device (which can be a personal computer, a server or a network device, etc.) to perform all or part of the steps of the various embodiments of the present application. The aforementioned memory includes: U disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), mobile hard disk, disk or optical disk and other media that can store program codes.

[0154] In the above embodiments, the description of each embodiment has its own emphasis. For the part not described in detail in a certain embodiment, please refer to the relevant description of other embodiments. The technical features of the above embodiments can be combined arbitrarily. In order to make the description concise, all possible combinations of the technical features in the above embodiments are not described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0155] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A battery pack insulation detection circuit, characterized in that: The insulation detection circuit comprises: a control module, an insulation module, a switch module and a heating film; The control module, the insulation module, the switch module and the heating film are all connected to the positive and negative electrodes of the battery pack, and the switch module is also connected to the outer shell of the battery pack; The control module is used to obtain the insulation voltage of the battery module to the insulation module, and determine whether the insulation of the heating film fails according to the insulation voltage.

2. The insulation detection circuit according to claim 1, characterized in that: The switch module includes: a first switch, a second switch and a third switch; A first end of the first switch is connected to the positive electrode of the battery module, and a second end of the first switch is connected to the outer shell of the battery pack; The first end of the second switch is connected to the positive electrode of the battery module through the heating film, and the second end of the second switch is connected to the outer shell of the battery pack; The first end of the third switch is connected to the positive electrode of the battery module, and the second end of the third switch is connected to the negative electrode of the battery module through the insulation module.

3. The insulation detection circuit according to claim 2, characterized in that: The insulation module includes a first resistor, a second resistor and a third resistor; The first resistor and the second resistor are connected in series between the positive electrode and the negative electrode of the battery module; A first end of the third resistor is connected to a second end of the third switch, and a second end of the third resistor is connected to a midpoint between the first resistor and the second resistor.

4. The insulation detection circuit according to claim 3, characterized in that: The switch module further includes: a fourth switch and a fifth switch; The first end of the heating film is connected to the positive electrode of the battery module through the fourth switch, the second end of the heating film is connected to the negative electrode of the battery module through the fifth switch, and the third end of the heating film is connected to the first end of the second switch.

5. The insulation detection circuit according to claim 4, characterized in that: The switch module further includes: a sixth switch and a seventh switch; A first end of the sixth switch is connected to the positive electrode of the battery module, and a second end of the sixth switch is connected to an external electrical device; A first end of the seventh switch is connected to the negative electrode of the battery module, and a second end of the seventh switch is connected to an external electrical device.

6. A battery pack insulation detection method, characterized in that: Applied to the battery pack insulation detection circuit according to any one of claims 1 to 5, the method comprising: When performing insulation detection, obtaining an insulation detection strategy; the insulation detection strategy is used to indicate the on-off state of the switch in the insulation detection circuit; Controlling the corresponding switch to be turned on or off according to the insulation detection strategy, and obtaining the positive electrode-to-shell voltage of the battery pack and the negative electrode-to-shell voltage of the battery module; The battery pack is subjected to insulation testing according to the positive electrode-to-shell voltage and the negative electrode-to-shell voltage.

7. The method according to claim 6, characterized in that The controlling the corresponding switch to be turned on or off according to the insulation detection strategy, and obtaining the positive electrode-to-shell voltage of the battery pack and the negative electrode-to-shell voltage of the battery module, includes: Controlling the sixth switch, the seventh switch and the first switch in the insulation detection circuit to be turned on, obtaining the first pair-shell voltage of the positive electrode and the first pair-shell voltage of the negative electrode, and then controlling the third switch to be turned on, obtaining the second pair-shell voltage of the positive electrode and the second pair-shell voltage of the negative electrode; The sixth switch, the seventh switch, and the second switch are controlled to be turned on to obtain the third pair-shell voltage of the positive electrode and the third pair-shell voltage of the negative electrode, and then the third switch is controlled to be turned on to obtain the fourth pair-shell voltage of the positive electrode and the fourth pair-shell voltage of the negative electrode.

8. The method according to claim 7, characterized in that The performing insulation detection on the battery pack according to the positive electrode-to-shell voltage and the negative electrode-to-shell voltage includes: Obtaining a first insulation resistance of the battery pack according to the first pair-of-shell voltage of the positive electrode and the first pair-of-shell voltage of the negative electrode, and the second pair-of-shell voltage of the positive electrode and the second pair-of-shell voltage of the negative electrode; Obtaining a second insulation resistance of the battery pack according to the third shell-to-shell voltage of the positive electrode and the third shell-to-shell voltage of the negative electrode, and the fourth shell-to-shell voltage of the positive electrode and the fourth shell-to-shell voltage of the negative electrode; An insulation test is performed on the battery pack according to the first insulation resistance and the second insulation resistance.

9. The method according to claim 8, characterized in that The performing insulation detection on the battery pack according to the first insulation resistance and the second insulation resistance includes: If the first insulation resistance is less than or equal to a preset resistance, and the second insulation resistance is less than or equal to the preset resistance, it is determined that the insulation of the heating film in the battery pack fails; If the first insulation resistance is less than or equal to a preset resistance, and the second insulation resistance is greater than the preset resistance, it is determined that the insulation of the heating film has not failed, and the insulation of other parts of the battery pack has failed; If the first insulation resistance is greater than a preset resistance and the second insulation resistance is less than or equal to the preset resistance, it is determined that the insulation of the heating film in the battery pack fails; If the first insulation resistance is greater than a preset resistance, and the second insulation resistance is greater than the preset resistance, it is determined that the battery pack insulation has not failed.

10. An electronic device, characterized in that: include: Memory for storing computer programs; A processor, configured to execute the computer program to implement the method according to any one of claims 6 to 9.

11. A computer-readable storage medium, characterized in that: A computer program is stored thereon, and the computer program is executed by a processor to implement the method according to any one of claims 6 to 9.

12. A computer program product, characterized in that The method comprises a computer program, which implements the method according to any one of claims 6 to 9 when executed by a controller.

13. A vehicle, characterized in that: The vehicle is provided with an insulation detection circuit as claimed in any one of claims 1 to 5.

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