Insulation detection circuit, battery management system, battery device and electric driving equipment

Abstract

The utility model discloses an insulation detection circuit, a battery management system, a battery device and electric driving equipment. The insulation detection circuit comprises a first detection branch, a second detection branch and a first switch branch. Wherein the insulation detection circuit is used for acquiring at least one first sampling signal provided by the first detection branch and / or at least one second sampling signal provided by the second detection branch when the first detection branch, the second detection branch and the first switch branch are in different states; wherein the at least one first sampling signal and / or the at least one second sampling signal are / is used for determining the resistance value of the positive ground insulation resistor and the resistance value of the negative ground insulation resistor. Therefore, the complexity and the cost of the circuit can be reduced, and the stability and the reliability of the circuit are improved.

Description

Technical Field

[0001] This utility model relates to the field of power electronics technology, and in particular to an insulation detection circuit, a battery management system, a battery device, and an electric drive device. Background Technology

[0002] Insulation resistance is a key indicator for evaluating the insulation performance of the vehicle's electrical equipment. The Battery Management System (BMS) determines the insulation performance of the vehicle by detecting whether the insulation resistance value is within the normal range.

[0003] In related technologies, insulation resistance can be monitored in real time by setting up an external insulation tester, or the insulation resistance value can be determined based on the bridge method by using the bridge arm circuit and operational amplifier conditioning circuit built into the BMS. However, these two solutions involve a large number of components, resulting in high complexity of the insulation detection circuit. Utility Model Content

[0004] This utility model mainly provides an insulation detection circuit, a battery management system, a battery device, and an electric drive device, which can reduce circuit complexity and cost, and improve circuit stability and reliability.

[0005] The technical solution of this utility model is implemented as follows:

[0006] In a first aspect, embodiments of the present invention provide an insulation detection circuit, which includes a first detection branch, a second detection branch, and a first switching branch; wherein:

[0007] The first end of the first detection branch is connected to the positive terminal of the battery pack, and the second end of the first detection branch is connected to the first end of the second detection branch; the third end of the first detection branch is connected to the negative terminal of the battery pack and the second end of the second detection branch, respectively.

[0008] The first switch branch is connected to the third end of the second detection branch, or the first switch branch is connected between the second end of the first detection branch and the first end of the second detection branch;

[0009] An insulation detection circuit is used to acquire at least one first sampling signal provided by the first detection branch and / or at least one second sampling signal provided by the second detection branch when the first detection branch, the second detection branch and the first switch branch are in different states.

[0010] Wherein, at least one first sampling signal and / or at least one second sampling signal are used to determine the resistance value of the positive-to-ground insulation resistance and the resistance value of the negative-to-ground insulation resistance.

[0011] By employing the aforementioned technical means, a first detection branch, a second detection branch, and a first switch branch are configured. When these three branches are in different states, at least one first sampling signal and / or at least one second sampling signal are acquired to determine the resistance values ​​of the positive-to-ground insulation resistance and the negative-to-ground insulation resistance. In this way, the insulation detection circuit reuses relevant sampling circuits, enabling the determination of the positive-to-ground insulation resistance and the negative-to-ground insulation resistance values ​​based on fewer components and a simpler circuit structure. This reduces circuit complexity and cost, and improves circuit stability and reliability.

[0012] In some embodiments, the first detection branch includes a first resistor, a second resistor, and a first switch; wherein: a first end of the first resistor is connected to the positive terminal of the battery pack and a first end of the second detection branch, respectively; a second end of the first resistor is connected to a first end of the first switch; a second end of the first switch is connected to a first end of the second resistor; a second end of the second resistor is connected to the negative terminal of the battery pack and a second end of the second detection branch, respectively; a first sampling point is provided between the second end of the first switch and the first end of the second resistor, and the first sampling point is used to sample at least one first sampling signal.

[0013] Through the above-mentioned technical means, the first detection branch includes a first resistor, a second resistor, and a first switch. A first sampling point is also set between the first resistor and the second resistor in the first detection branch. The voltage value at both ends of the battery pack can be accurately determined based on the voltage division method, reducing redundant devices, thereby reducing costs and circuit complexity.

[0014] In some embodiments, the second detection branch includes a first voltage divider branch and a second switch branch; wherein: the first end of the first voltage divider branch is connected to the positive terminal of the battery pack and the first end of the first detection branch; the second end of the first voltage divider branch is connected to the negative terminal of the battery pack, the second end of the first detection branch and the second end of the second switch branch are respectively connected; and the first end of the second switch branch is connected to the third end of the first voltage divider branch.

[0015] Using the above-mentioned technical means, the second detection branch includes a first voltage divider branch and a second switch branch. Based on the conduction or cutoff of the second switch branch, the series and parallel relationship of the resistors in the first voltage divider branch is controlled, thereby obtaining the results of the second sampling signal sampled under different states of the first voltage divider branch. Based on a simple circuit structure, at least one second voltage signal is obtained according to the corresponding voltage ratio, further realizing the accurate calculation of the subsequent positive-to-ground insulation resistance and negative-to-ground insulation resistance.

[0016] In some embodiments, the first voltage divider branch includes a third resistor, a fourth resistor, a fifth resistor, and a sixth resistor; wherein: the first end of the third resistor is connected to the positive terminal of the battery pack and the first end of the first detection branch; the second end of the third resistor is connected to the first end of the fourth resistor and the first end of the second switch branch, respectively; the second end of the fourth resistor is connected to the first end of the fifth resistor; the second end of the fifth resistor is connected to the first end of the sixth resistor; and the second end of the sixth resistor is connected to the negative terminal of the battery pack, the second end of the first detection branch, and the second end of the second switch branch, respectively.

[0017] Using the above-mentioned technical means, the first voltage divider branch includes a series circuit composed of the third, fourth, fifth, and sixth resistors. Based on the control of the second switch branch to turn on or off, the series and parallel connection mode of each resistor is changed, and different second sampling signals are obtained with a simple circuit structure, thereby realizing the accurate measurement of insulation resistance.

[0018] In some embodiments, the second switch branch includes a second switch; wherein: the first terminal of the second switch is connected to the second terminal of the third resistor and the first terminal of the fourth resistor respectively, and the second terminal of the second switch is connected to the second terminal of the sixth resistor, the negative terminal of the battery pack and the second terminal of the first detection branch respectively.

[0019] Through the above-mentioned technical means, the second switch changes the series and parallel connection state of the resistors in the first voltage divider branch under different states, and obtains the second sampling signal under different states. Thus, based on a simple circuit structure, the accurate measurement of the insulation resistance value can be achieved.

[0020] In some embodiments, the first switch branch includes a third switch; wherein: the first terminal of the third switch is connected to the second terminal of the fourth resistor and the first terminal of the fifth resistor respectively; and the second terminal of the third switch is grounded.

[0021] Through the above-mentioned technical means, the first switch branch includes a third switch. By flexibly switching the sampling path, different second sampling signals can be obtained, thereby realizing the accurate solution of the positive-to-ground insulation resistance and the negative-to-ground insulation resistance.

[0022] In some embodiments, a second sampling point is provided between the second end of the fifth resistor and the first end of the sixth resistor, the second sampling point being used to sample at least one second sampling signal.

[0023] By using the above-mentioned technical means, a second sampling point is set between the fifth and sixth resistors. This is used to sample at least one second sampling signal with different voltage division ratios when the insulation detection circuit is in different stages, thereby accurately determining the resistance value of the positive-to-ground insulation resistance and the resistance value of the negative-to-ground insulation resistance.

[0024] In some embodiments, the first switch branch includes a fourth switch; wherein: the first terminal of the fourth switch is connected to the second terminal of the fifth resistor and the first terminal of the sixth resistor respectively; and the second terminal of the fourth switch is grounded.

[0025] Through the above-mentioned technical means, the first switch branch includes a fourth switch. By flexibly switching the sampling path, different second sampling signals can be obtained, thereby realizing the accurate solution of the positive-to-ground insulation resistance and the negative-to-ground insulation resistance.

[0026] In some embodiments, a third sampling point is provided between the second end of the fourth resistor and the first end of the fifth resistor, the third sampling point being used to sample at least one second sampling signal.

[0027] Using the above-mentioned technical means, a third sampling point is set between the fourth and fifth resistors. This is used to sample at least one second sampling signal by different voltage division ratios when the insulation detection circuit is in different stages, thereby accurately determining the resistance value of the positive-to-ground insulation resistance and the resistance value of the negative-to-ground insulation resistance.

[0028] In some embodiments, the first detection branch includes a seventh resistor, an eighth resistor, a ninth resistor, and a fifth switch; wherein: the first end of the seventh resistor is connected to the positive terminal of the battery pack, and the second end of the seventh resistor is connected to the first end of the fifth switch; the second end of the fifth switch is connected to the first end of the second detection branch, the first end of the eighth resistor, and the first switch branch, respectively; the second end of the eighth resistor is connected to the first end of the ninth resistor; the second end of the ninth resistor is connected to the negative terminal of the battery pack and the second end of the second detection branch, respectively; a fourth sampling point is provided between the second end of the eighth resistor and the first end of the ninth resistor, and the fourth sampling point is used to sample at least one first sampling signal.

[0029] Using the aforementioned technical means, the first detection branch includes a seventh resistor, an eighth resistor, a ninth resistor, and a fifth switch. By dividing the voltage across each resistor and turning the fifth switch on or off, at least one first sampling signal is acquired, thereby determining the resistance value of the insulation resistance. This approach reduces the number of components used and lowers circuit costs while ensuring the accuracy of the insulation resistance readings.

[0030] In some embodiments, the second detection branch includes a tenth resistor and a sixth switch; wherein: the first terminal of the sixth switch is connected to the second terminal of the fifth switch, the first terminal of the eighth resistor and the first switch branch respectively, the second terminal of the sixth switch is connected to the first terminal of the tenth resistor; the second terminal of the tenth resistor is connected to the negative terminal of the battery pack and the second terminal of the ninth resistor respectively.

[0031] Using the aforementioned technical means, at least one first sampling signal is acquired when the second detection branch and the first detection branch are in different states. This first sampling signal is then used to determine the resistance value of the positive-to-ground insulation resistance and the resistance value of the negative-to-ground insulation resistance. This achieves accurate and efficient detection of the insulation resistance value with a simple circuit structure.

[0032] In some embodiments, the first switch branch includes a seventh switch; wherein: the first terminal of the seventh switch is connected to the first terminal of the sixth switch, the first terminal of the eighth resistor, and the second terminal of the fifth switch respectively; the second terminal of the seventh switch is grounded.

[0033] By using the above-mentioned technical means, the sampling path can be flexibly switched by controlling the opening or closing of the seventh switch, different first sampling signals can be obtained, thereby realizing the accurate solution of the positive-to-ground insulation resistance and the negative-to-ground insulation resistance.

[0034] In a second aspect, embodiments of the present invention provide a battery management system, which includes a control branch and an insulation detection circuit as described in any of the first aspects, wherein the control branch is connected to the insulation detection circuit; wherein:

[0035] A control branch is used to determine the resistance value of the positive-to-ground insulation resistance and the resistance value of the negative-to-ground insulation resistance based on at least one first sampling signal and / or at least one second sampling signal obtained by the insulation detection circuit.

[0036] Thirdly, embodiments of the present invention provide a battery device, including: a battery and a battery management system as described in the second aspect.

[0037] Fourthly, embodiments of the present invention provide an electric drive device, which includes a battery device as described in the third aspect.

[0038] It should be understood that the above general description and the following detailed description are merely exemplary and explanatory, and are not intended to limit the technical solutions of this utility model. Attached Figure Description

[0039] Figure 1 A schematic diagram of an insulation detection circuit provided for an embodiment of this utility model. Figure 1 ;

[0040] Figure 2 A schematic diagram of an insulation detection circuit provided for an embodiment of this utility model. Figure 2 ;

[0041] Figure 3 A schematic diagram of an insulation detection circuit provided for an embodiment of this utility model. Figure 3 ;

[0042] Figure 4A schematic diagram of an insulation detection circuit provided for an embodiment of this utility model. Figure 4 ;

[0043] Figure 5 A schematic diagram of an insulation detection circuit provided for an embodiment of this utility model. Figure 5 ;

[0044] Figure 6 A schematic diagram of an insulation detection circuit provided for an embodiment of this utility model. Figure 6 ;

[0045] Figure 7 A schematic diagram of an insulation detection circuit provided for an embodiment of this utility model. Figure 7 ;

[0046] Figure 8 A schematic diagram of an insulation detection circuit provided for an embodiment of this utility model. Figure 8 ;

[0047] Figure 9 A schematic diagram of an insulation detection circuit provided for an embodiment of this utility model. Figure 9 ;

[0048] Figure 10 A schematic diagram of the composition structure of a battery management system provided for an embodiment of this utility model;

[0049] Figure 11 This is a schematic diagram of the composition structure of a battery device provided in an embodiment of the present utility model;

[0050] Figure 12 This is a schematic diagram of the composition structure of an electric drive device provided in an embodiment of the present utility model. Detailed Implementation

[0051] To gain a more detailed understanding of the features and technical content of the embodiments of this utility model, the implementation of the embodiments of this utility model will be described in detail below with reference to the accompanying drawings. The accompanying drawings are for reference and illustration only and are not intended to limit the embodiments of this utility model.

[0052] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein is for the purpose of describing embodiments of the invention only and is not intended to limit the invention.

[0053] In the following description, references are made to “some embodiments,” which describe a subset of all possible embodiments. However, it is understood that “some embodiments” may be the same subset or different subsets of all possible embodiments and may be combined with each other without conflict.

[0054] It should also be noted that the terms "first, second, third" used in the embodiments of this utility model are only used to distinguish similar objects and do not represent a specific order of objects. It is understood that "first, second, third" can be interchanged in a specific order or sequence where permitted, so that the embodiments of this utility model described herein can be implemented in an order other than that illustrated or described herein.

[0055] Furthermore, the reference to "embodiment" herein means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of the present invention. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0056] The following is a description of the relevant technologies of this utility model.

[0057] New energy batteries are being used more and more widely in daily life and industry. For example, new energy vehicles equipped with batteries are already widely used. In addition, batteries are being used more and more in the field of energy storage.

[0058] Currently, new energy batteries are being used more and more widely in daily life and industry. They are not only used in energy storage systems for hydropower, thermal power, wind power, and solar power plants, but also extensively in electric vehicles such as electric bicycles, electric motorcycles, and electric cars, as well as in aerospace and other fields. With the continuous expansion of the application areas of power batteries, the market demand is also constantly increasing.

[0059] In this embodiment of the invention, the battery can be a single battery cell or a battery pack composed of multiple battery cells. A single battery cell is a basic unit capable of converting chemical energy into electrical energy, and can be used to manufacture battery modules or battery packs to supply power to electrical devices. A single battery cell can be a rechargeable battery, which is a battery cell that can be recharged after discharge to reactivate its active materials and continue to be used. Battery cells can be lithium-ion batteries, sodium-ion batteries, sodium-lithium-ion batteries, lithium metal batteries, sodium metal batteries, lithium-sulfur batteries, magnesium-ion batteries, nickel-metal hydride batteries, nickel-cadmium batteries, lead-acid batteries, etc., and this embodiment is not limited to these types.

[0060] In this embodiment of the invention, the battery may also be a single physical module comprising one or more battery cells to provide higher voltage and capacity. When there are multiple battery cells, the multiple battery cells are connected in series, parallel, or mixed via a busbar.

[0061] With the continuous optimization of the new energy vehicle standard system, rigorous safety tests are required during the design and production of electronic and electrical products to ensure they meet specifications and safety standards. These safety tests include withstand voltage performance, insulation performance, and load power. When measuring the insulation performance of the entire vehicle, the primary focus is on the insulation resistance value, i.e., the resistance between live components and reference platforms such as the casing and ground. The BMS (Battery Management System) determines the overall insulation performance of the vehicle by judging whether the insulation resistance value is within the normal range.

[0062] In related technologies, two main strategies are used for insulation resistance testing of new energy vehicles. One is to obtain the insulation resistance value through an external insulation tester, and the other is to use the circuit built into the BMS to detect the insulation resistance value.

[0063] In the case of a solution that uses an independent insulation tester, the insulation tester monitors the resistance value of the insulation resistance in real time and sends the monitored insulation resistance value to the vehicle control unit (VCU) via the controller area network (CAN) bus. The VCU determines whether the insulation resistance value is within the safe range to ensure that the insulation performance of the whole vehicle is normal.

[0064] Alternatively, for BMS built-in solutions, the main methods currently used are balanced bridge method, unbalanced bridge method, DC injection method, and current sensing method. Among them, the balanced bridge method connects large-value resistors in parallel with the positive and negative insulation resistances, and is also equipped with a fixed bridge. When the insulation performance of the whole vehicle deteriorates, the BMS monitors the change in the resistance value of the insulation resistance, and the bridge becomes unbalanced.

[0065] However, the two solutions mentioned above use a relatively large number of components, resulting in higher complexity and cost of the insulation detection circuit.

[0066] Based on this, the present invention provides an insulation detection circuit, a battery management system, a battery device, and an electric drive device. It includes a first detection branch, a second detection branch, and a first switch branch. When the first detection branch, the second detection branch, and the first switch branch are in different states, at least one first sampling signal and / or at least one second sampling signal are acquired to determine the resistance values ​​of the positive-to-ground insulation resistance and the negative-to-ground insulation resistance. In this way, the insulation detection circuit reuses related sampling circuits, enabling the determination of the resistance values ​​of the positive-to-ground insulation resistance and the negative-to-ground insulation resistance based on fewer components and a simpler circuit structure. This reduces circuit complexity and cost, and improves circuit stability and reliability.

[0067] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0068] In one embodiment of this utility model, such as Figure 1 and Figure 2 As shown, this embodiment of the invention provides an insulation detection circuit 10, which includes a first detection branch 101, a second detection branch 102, and a first switch branch 103; wherein:

[0069] The first end of the first detection branch 101 is connected to the positive terminal of the battery pack 104, and the second end of the first detection branch 101 is connected to the first end of the second detection branch 102; the third end of the first detection branch 101 is connected to the negative terminal of the battery pack 104 and the second end of the second detection branch 102, respectively.

[0070] The first switch branch 103 is connected to the third end of the second detection branch 102, or the first switch branch 103 is connected between the second end of the first detection branch 101 and the first end of the second detection branch 102.

[0071] like Figure 1 As shown, the first switch branch 103 is connected to the end of the second detection branch 102 away from the first detection branch 101, that is, the first switch branch 103 is connected to the third end of the second detection branch 102; or, as Figure 2 As shown, the first switch branch 103 is connected between the second end of the first detection branch 101 and the first end of the second detection branch 102.

[0072] The insulation detection circuit 10 is used to acquire at least one first sampling signal provided by the first detection branch 101 and / or at least one second sampling signal provided by the second detection branch when the first detection branch 101, the second detection branch 102 and the first switch branch 103 are in different states.

[0073] Wherein, at least one first sampling signal and / or at least one second sampling signal are used to determine the resistance value of the positive-to-ground insulation resistance Rp and the resistance value of the negative-to-ground insulation resistance Rn.

[0074] It should be noted that the positive-to-ground insulation resistance Rp can represent the equivalent resistance of all leakage current paths between the positive terminal of the DC bus and ground in the circuit, and the negative-to-ground insulation resistance Rn can represent the equivalent resistance of all leakage current paths between the negative terminal of the DC bus and ground in the circuit. There are no actual devices for the positive-to-ground insulation resistance Rp and the negative-to-ground insulation resistance Rn in the insulation detection circuit.

[0075] In this embodiment of the invention, the first detection branch 101 can be understood as an insulated sampling bridge arm branch connected in parallel to both ends of the battery pack 104. The first detection branch 101 may be in different states, including being in a conducting state or a turning-off state. The internal connection method of the first detection branch 101 in different states and its connection method with other devices in the circuit are different.

[0076] Specifically, when the first detection branch 101 is in different states, a first sampling signal is acquired at a preset sampling position in the first detection branch 101 to obtain at least one first sampling signal. The first sampling signal can be a voltage signal, used to characterize the voltage value acquired based on the voltage division ratio across the battery pack 104 after voltage division by a resistor.

[0077] In this embodiment of the invention, the second detection branch 102 can be understood as another insulated sampling bridge arm branch. The second detection branch 102 is connected to a point in the first detection branch 101, or to a point at either end of the first detection branch 101. The second detection branch 102 may be in different states, including being in a conducting state or a turning-off state. The internal connection methods of the second detection branch 102 in different states, as well as its connection methods with other devices in the circuit, are different.

[0078] Specifically, when the second detection branch 102 is in different states, a second sampling signal is acquired at a preset sampling position in the second detection branch 102 to obtain at least one second sampling signal. The second sampling signal can be a voltage signal, used to characterize the voltage value acquired based on the voltage division ratio across the positive-to-ground insulation resistance Rp or the negative-to-ground insulation resistance Rn after voltage division by a resistor.

[0079] In the embodiments of this utility model, such as Figure 1 As shown, the first end of the first switch branch 103 can be connected to the end of the second detection branch 102 that is away from the first detection branch 101, and the second end of the first switch branch 103 is grounded.

[0080] Alternatively, in some embodiments, such as Figure 2 As shown, the first end of the first switch branch 103 can be connected to a certain position in the first detection branch 101, and the second end of the first switch branch 103 is grounded.

[0081] The first switch branch 103 may be in different states, including being in a conducting state and a turning-off state. When the first switch branch 103 is in different states, it can control the connection or disconnection of certain paths in the circuit, thereby changing the voltage division relationship of at least a part of the circuit in the insulation detection circuit 10, and thus changing the voltage value of the second sampling signal sampled by the second detection branch 102.

[0082] In this embodiment of the invention, when the first detection branch 101 and the second detection branch 102 are in different states, the voltage distribution of the first detection branch 101 and the second detection branch 102 will also change, resulting in the first sampling signal and the second sampling signal obtained by sampling being different.

[0083] It should be noted that the combination of the first detection branch 101, the second detection branch 102, and the first switch branch 103 being in corresponding states is referred to as the insulation detection circuit 10 being in a certain sampling stage. A first sampling signal and a second sampling signal are obtained by sampling in a certain sampling stage, and at least one first sampling signal and at least one second sampling signal are obtained by sampling in different sampling stages.

[0084] It should also be noted that, based on Ohm's law, the voltage ratio corresponds to the resistance ratio. In this embodiment of the invention, the series and parallel connection of the resistors in the circuit are different in different sampling stages, and the corresponding first sampling signal and at least one second sampling signal are different. By solving the system of equations for the voltage and resistance ratios in different stages, the resistance values ​​of the positive-to-ground insulation resistance Rp and the negative-to-ground insulation resistance Rn can be solved.

[0085] This invention provides an insulation detection circuit, comprising a first detection branch, a second detection branch, and a first switch branch. When the first detection branch, the second detection branch, and the first switch branch are in different states, at least one first sampling signal and / or at least one second sampling signal are acquired to determine the resistance values ​​of the positive-to-ground insulation resistance and the negative-to-ground insulation resistance. Thus, the insulation detection circuit reuses related sampling circuits, enabling the determination of the positive-to-ground insulation resistance and the negative-to-ground insulation resistance values ​​based on fewer components and a simpler circuit structure, reducing circuit complexity and cost, and improving circuit stability and reliability.

[0086] In another embodiment of this utility model, based on Figure 1 The illustrated embodiment, as Figure 3 As shown, the first detection branch 101 includes a first resistor R1, a second resistor R2, and a first switch K1; wherein:

[0087] The first end of the first resistor R1 is connected to the positive terminal of the battery pack and the first end of the second detection branch 102, respectively, and the second end of the first resistor R1 is connected to the first end of the first switch K1.

[0088] The second terminal of the first switch K1 is connected to the first terminal of the second resistor R2, and the second terminal of the second resistor R2 is connected to the negative terminal of the battery pack and the second terminal of the second detection branch 102 respectively.

[0089] A first sampling point is set between the second terminal of the first switch K1 and the first terminal of the second resistor R2. The first sampling point is used to sample at least one first sampling signal.

[0090] In this embodiment of the invention, the first resistor R1 and the second resistor R2 form a series path and are controlled by the first switch K1. The first end of the first resistor R1 is connected to the positive terminal of the battery pack, and the second end of the second resistor R2 is connected to the negative terminal of the battery pack, forming a loop. The first switch K1 is used to control whether the loop is open or closed.

[0091] In this embodiment of the present invention, when the first switch K1 is turned on, the first detection branch 101 is in the conducting state, and the current can flow through the first resistor R1 and the second resistor R2, thereby generating a voltage difference in the circuit. Based on the voltage division ratio of the first resistor R1 and the second resistor R2, the first sampling signal is obtained by sampling.

[0092] It should be noted that, based on Figure 3 In the circuit structure shown, the ratio of the voltage value of the first sampling signal to the voltage value across the battery pack is equal to the ratio of the second resistor R2 to the sum of the first resistor R1 and the second resistor R2. Based on this voltage division ratio, the voltage across the battery pack can be determined based on the first sampling signal, the first resistor R1, and the second resistor R2.

[0093] It should also be noted that the first sampling point can also be set between the first end of the first switch K1 and the second end of the first resistor R1, with the same voltage division ratio as described above, so that the voltage across the battery pack can be determined based on the first sampling signal, the first resistor R1 and the second resistor R2.

[0094] This utility model embodiment provides an insulation detection circuit. The first detection branch includes a first resistor, a second resistor, and a first switch. A first sampling point is also set between the first resistor and the second resistor in the first detection branch. It can accurately determine the voltage value at both ends of the battery pack based on the voltage division method, reduce redundant components, thereby reducing costs and circuit complexity.

[0095] In some embodiments, such as Figure 3 As shown, the second detection branch includes a first voltage divider branch 1021 and a second switch branch 1022; wherein:

[0096] The first end of the first voltage divider branch 1021 is connected to the positive terminal of the battery pack and the first end of the first detection branch 101. The second end of the first voltage divider branch 1021 is connected to the negative terminal of the battery pack, the second end of the first detection branch 101, and the second end of the second switch branch 1022, respectively.

[0097] The first end of the second switch branch 1022 is connected to the third end of the first voltage divider branch 1021.

[0098] In this embodiment of the invention, the first voltage divider branch 1021 can be a circuit structure composed of multiple resistors connected in series. The first end of the first voltage divider branch 1021 is connected to the positive terminal of the battery pack, and the second end of the second voltage divider branch is connected to the negative terminal of the battery pack. Therefore, the output voltage at sampling points located at different positions in the first voltage divider branch 1021 is the output voltage across the battery pack proportional to the resistance.

[0099] In this embodiment of the present invention, the second switch branch 1022 may include one or more controllable switch circuit paths for controlling whether the current passes through a certain branch, thereby changing the connection relationship between the resistor in the first voltage divider branch 1021 and other parts of the insulation detection circuit, and thus affecting the voltage value of the second sampling signal.

[0100] It should be noted that when the second switch branch 1022 is in the on state, the second detection branch is also in the on state, so that the second detection branch is connected in parallel with a portion of the resistors in the battery pack; or, when the second switch branch 1022 is in the off state, the first voltage divider branch 1021 is connected in parallel with the battery pack and the first detection branch 101.

[0101] It should also be noted that, under different states of the first voltage divider branch 1021, the second sampling signal of the pre-set sampling point in the first voltage divider branch 1021 is sampled respectively to obtain at least one second sampling signal.

[0102] This utility model embodiment provides an insulation detection circuit. The second detection branch includes a first voltage divider branch and a second switch branch. Based on the conduction or cutoff of the second switch branch, the series and parallel relationship of the resistors in the first voltage divider branch is controlled, thereby obtaining the results of the second sampling signal sampled under different states of the first voltage divider branch. Based on a simple circuit structure, at least one second voltage signal is obtained according to the corresponding voltage ratio, further realizing the accurate calculation of the positive to ground insulation resistance and the negative to ground insulation resistance.

[0103] In some embodiments, such as Figure 3 As shown, the first voltage divider branch 1021 includes a third resistor R3, a fourth resistor R4, a fifth resistor R5, and a sixth resistor R6; wherein:

[0104] The first end of the third resistor R3 is connected to the positive terminal of the battery pack and the first end of the first detection branch 101, and the second end of the third resistor R3 is connected to the first end of the fourth resistor R4 and the first end of the second switch branch 1022 respectively.

[0105] The second terminal of the fourth resistor R4 is connected to the first terminal of the fifth resistor R5;

[0106] The second terminal of the fifth resistor R5 is connected to the first terminal of the sixth resistor R6;

[0107] The second terminal of the sixth resistor R6 is connected to the negative terminal of the battery pack, the second terminal of the first detection branch 101, and the second terminal of the second switch branch 1022, respectively.

[0108] In this embodiment of the present invention, the first voltage divider branch includes a third resistor R3, a fourth resistor R4, a fifth resistor R5, and a sixth resistor R6 connected in series. The first end of the third resistor R3 is connected to the positive terminal of the battery pack and the first end of the first detection branch 101, and the second end of the sixth resistor R6 is connected to the negative terminal of the battery pack and the second end of the first detection branch 101. In other words, the first voltage divider branch 1021 is connected in parallel with the first detection branch 101 and the branch where the battery pack is located.

[0109] In this embodiment of the invention, a sampling point can be set between two of the above-mentioned multiple resistors. Based on the precise voltage division provided by the resistor chain formed by each resistor, without adding any components, the first voltage divider branch 1021 can provide a second sampling signal by controlling the conduction or cutoff of the second switch branch 1022.

[0110] This utility model embodiment provides an insulation detection circuit. The first voltage divider branch includes a series circuit composed of a third resistor, a fourth resistor, a fifth resistor, and a sixth resistor. Based on the control of the conduction or cutoff of the second switch branch, the series and parallel connection mode of each resistor is changed, and different second sampling signals are obtained with a simple circuit structure, thereby realizing accurate measurement of insulation resistance.

[0111] In some embodiments, such as Figure 3 As shown, the second switch branch 1022 includes a second switch K2; wherein:

[0112] The first terminal of the second switch K2 is connected to the second terminal of the third resistor R3 and the first terminal of the fourth resistor R4 respectively. The second terminal of the second switch K2 is connected to the second terminal of the sixth resistor R6, the negative terminal of the battery pack and the second terminal of the first detection branch 101 respectively.

[0113] In this embodiment of the invention, the second switch K2 is used to control the on / off state of its branch, thereby changing the state of the second detection branch 102. Specifically, when the second switch K2 is in the on state, the second detection branch 102 is in the on state; or, when the second switch K2 is in the off state, the second detection branch 102 is in the off state.

[0114] When the second switch K2 is in the off state, the second detection branch 102 is also in the off state, and its equivalent circuit diagram is as follows: Figure 4As shown, the third resistor R3, the fourth resistor R4, the fifth resistor R5, and the sixth resistor R6 in the first voltage divider branch are connected in series and in parallel with the battery pack and the branch where the first detection branch 101 is located.

[0115] Alternatively, when the second switch K2 is in the ON state, the second detection branch 102 is in the ON state, and its equivalent circuit diagram is as follows: Figure 5 As shown, the third resistor R3 is connected to the negative terminal of the battery pack through the branch where the second switch K2 is located, disconnecting its parallel connection with the positive ground insulation resistor Rp. The fourth resistor R4 is connected to the negative terminal of the battery pack through the second switch K2, and is connected in parallel with the negative ground insulation resistor Rn.

[0116] This utility model embodiment provides an insulation detection circuit. When the second switch is in different states, it changes the series and parallel connection state of the resistors in the first voltage divider branch to obtain the second sampling signal under different states. Thus, based on a simple circuit structure, it realizes the accurate measurement of the resistance value of the insulation resistance.

[0117] In some embodiments, such as Figure 3 As shown, a second sampling point is set between the second end of the fifth resistor R5 and the first end of the sixth resistor R6. The second sampling point is used to sample at least one second sampling signal.

[0118] In this embodiment of the invention, a second sampling point is set between the fifth resistor R5 and the sixth resistor R6 to collect the second sampling signal.

[0119] Specifically, when the second switch K2 is in the ON state, the corresponding second sampling signal is sampled. The voltage across the battery pack is divided by the third resistor R3, the fourth resistor R4, the fifth resistor R5, and the sixth resistor R6. The obtained second sampling signal is the voltage value of the sixth resistor R6. Further, based on the ratio of the fifth resistor R5 to the sum of the fifth resistor R5 and the sixth resistor R6, the voltage division ratio of the second sampling signal to the voltage Un across the negative-to-ground insulation resistance Rn is determined, thereby determining the corresponding voltage Un1 across the negative-to-ground insulation resistance Rn.

[0120] Alternatively, with the second switch K2 off, the corresponding second sampling signal is sampled. After the voltage across the battery pack is divided by the fourth resistor R4, the fifth resistor R5, and the sixth resistor R6, the voltage Un2 across the corresponding negative-to-ground insulation resistance Rn is determined based on the corresponding voltage division ratio, the second sampling signal, and the voltage across the battery pack.

[0121] This utility model embodiment provides an insulation detection circuit, which sets a second sampling point between the fifth resistor and the sixth resistor. This point is used to sample at least one second sampling signal by different voltage division ratios when the insulation detection circuit is in different stages, thereby accurately determining the resistance value of the positive-to-ground insulation resistance and the resistance value of the negative-to-ground insulation resistance.

[0122] In some embodiments, the first switch branch 103 includes a third switch K3; wherein:

[0123] The first terminal of the third switch K3 is connected to the second terminal of the fourth resistor R4 and the first terminal of the fifth resistor R5, respectively.

[0124] The second terminal of the third switch K3 is grounded.

[0125] In this embodiment of the invention, when the third switch K3 is in the ON state, the first switch branch 103 is in the ON state; or, when the third switch K3 is in the OFF state, the first switch branch 103 is in the OFF state.

[0126] When the first switch K1, the second switch K2, and the third switch K3 are in different states, the connection path in the control circuit can change, thereby changing the series and parallel relationship of the resistors in the insulation sampling circuit, causing the voltage values ​​of the first sampling signal and the second sampling signal to change.

[0127] This utility model embodiment provides an insulation detection circuit. The first switch branch includes a third switch. By flexibly switching the sampling path, different second sampling signals can be obtained, thereby realizing the accurate solution of the positive to ground insulation resistance and the negative to ground insulation resistance.

[0128] In this embodiment of the utility model, based on Figures 3 to 5 The insulation sampling circuit shown can have a sampling process that includes two stages:

[0129] Phase 1: Controlling the first switch K1 and the third switch K3 to close, and the second switch K2 to close. Its equivalent circuit diagram is as follows: Figure 4 As shown above, in this case, the voltage Ubat across the battery pack is determined based on the first sampled signal, the voltage Un1 across the negative-to-ground insulation resistor Rn is determined based on the second sampled signal, and further, the voltage Up1 across the positive-to-ground insulation resistor Rp is determined to be Ubat - Un1. Based on... Figure 4 In the circuit structure shown, the third resistor R3 and the fourth resistor R4 are connected in parallel with the positive ground insulation resistance Rp, and the fifth resistor R5 and the sixth resistor R6 are connected in parallel with the negative ground insulation resistance Rn. Equation (1) can be obtained regarding the positive ground insulation resistance Rp and the negative ground insulation resistance Rn:

[0130] Up1 / Un1=Rp / / (R3+R4) / Rn / / (R5+R6)(1)

[0131] Second stage: Controlling the first switch K1, the second switch K2, and the third switch K3 to all close, the equivalent circuit diagram is as follows. Figure 5 As shown above, the third resistor R3 and the fourth resistor R4 are connected to the negative terminal of the battery pack through the second switch K2, disconnecting the parallel connection with the positive ground insulation resistor Rp. The fourth resistor R4 is connected in parallel with the negative ground insulation resistor Rn. Since the resistances connected in parallel with the positive ground insulation resistor Rp and the negative ground insulation resistor Rn have changed, the voltage in the circuit is redistributed, and the equation (2) regarding the positive ground insulation resistor Rp and the negative ground insulation resistor Rn can be obtained:

[0132] Up2 / Un3=Rp / Rn / / R4 / / (R5+R6)(2)

[0133] In this embodiment of the utility model, by solving the above equations (1) and (2) simultaneously, the positive ground insulation resistance Rp and the negative ground insulation resistance Rn can be calculated and determined.

[0134] In another embodiment of this utility model, based on Figure 1 The illustrated embodiment, as Figure 6 As shown, the first detection branch 101 includes a first resistor R1, a second resistor R2, and a first switch K1; wherein:

[0135] The first end of the first resistor R1 is connected to the positive terminal of the battery pack, and the second end of the first resistor R1 is connected to the first end of the first switch K1.

[0136] The second terminal of the first switch K1 is connected to the first terminal of the second resistor R2, and the second terminal of the second resistor R2 is connected to the negative terminal of the battery pack.

[0137] A first sampling point is set between the second terminal of the first switch K1 and the first terminal of the second resistor R2. The first sampling point is used to sample at least one first sampling signal.

[0138] The relevant description of the first detection branch 101 can be found in the aforementioned embodiments.

[0139] In some embodiments, such as Figure 6 As shown, the second detection branch 102 includes a first voltage divider branch 1021 and a second switch branch 1022; wherein:

[0140] The first end of the first voltage divider branch 1021 is connected to the positive terminal of the battery pack and the first end of the first detection branch 101. The second end of the first voltage divider branch 1021 is connected to the negative terminal of the battery pack, the second end of the first detection branch 101, and the second end of the second switch branch 1022, respectively.

[0141] The first end of the second switch branch 1022 is connected to the third end of the first voltage divider branch 1021.

[0142] In some embodiments, the first voltage divider branch 1021 includes a third resistor R3, a fourth resistor R4, a fifth resistor R5, and a sixth resistor R6; wherein:

[0143] The first end of the third resistor R3 is connected to the positive terminal of the battery pack and the first end of the first detection branch 101, and the second end of the third resistor R3 is connected to the first end of the fourth resistor R4 and the first end of the second switch branch 1022 respectively.

[0144] The second terminal of the fourth resistor R4 is connected to the first terminal of the fifth resistor R5;

[0145] The second terminal of the fifth resistor R5 is connected to the first terminal of the sixth resistor R6;

[0146] The second terminal of the sixth resistor R6 is connected to the negative terminal of the battery pack, the second terminal of the first detection branch 101, and the second terminal of the second switch branch 1022, respectively.

[0147] A third sampling point is set between the second end of the fourth resistor R4 and the first end of the fifth resistor R5. The third sampling point is used to sample at least one second sampling signal.

[0148] In this embodiment of the invention, the descriptions of the third resistor R3, the fourth resistor R4, the fifth resistor R5, and the sixth resistor R6 are as described in the foregoing embodiments.

[0149] In this embodiment of the invention, a third sampling point is set between the fourth resistor R4 and the fifth resistor R5, and the second sampling signal is collected when the second switch branch 1022 is in different states, so as to obtain at least one second sampling signal.

[0150] It should be noted that the voltage Up across the insulation resistor directly to ground can be determined based on the second sampling signal and the voltage of the battery pack divided by the third resistor R3 and the fourth resistor R4.

[0151] It should also be noted that, for Figure 6 The insulation detection circuit shown has its third terminal in the first voltage divider branch 1021 connected to the fifth resistor R5 and the sixth resistor R6; for Figure 5 In the insulation detection circuit shown, the third terminal of the first voltage divider branch 1021 is the connection point between the fourth resistor R4 and the fifth resistor R5.

[0152] In some embodiments, the first switch branch 103 may be connected to other locations of the first voltage divider branch 1021, and the second switch branch 1022 may be connected to other locations of the first voltage divider branch. The voltage Up across the positive-to-ground insulation resistor Rp or the voltage Un across the negative-to-ground insulation resistor Rn is determined based on the second sampling signal. However, if the first switch branch 103 and the second switch branch 1022 are connected to the same location, a short circuit may occur when the second switch K2 and the third switch K3 are closed.

[0153] This utility model embodiment provides an insulation detection circuit, which sets a third sampling point between a fourth resistor and a fifth resistor. This point is used to sample at least one second sampling signal by different voltage division ratios when the insulation detection circuit is in different stages, thereby accurately determining the resistance value of the positive-to-ground insulation resistance and the resistance value of the negative-to-ground insulation resistance.

[0154] In some embodiments, the second switch branch 1022 includes a second switch K2; wherein:

[0155] The first terminal of the second switch K2 is connected to the second terminal of the third resistor R3 and the first terminal of the fourth resistor R4 respectively. The second terminal of the second switch K2 is connected to the second terminal of the sixth resistor R6, the negative terminal of the battery pack and the second terminal of the first detection branch 101 respectively.

[0156] In this embodiment of the invention, when the second switch K2 is in the off state, the second detection branch 102 is in the off state, and its equivalent circuit diagram is as follows: Figure 7 As shown. In this case, the third resistor R3, the fourth resistor R4, and the fifth resistor R5 are connected in parallel with the positive ground insulation resistance Rp, and the sixth resistor R6 is connected in parallel with the negative ground insulation resistance Rn.

[0157] Alternatively, in some embodiments, when the second switch K2 is in the ON state, the second detection branch 102 is in the ON state, and its equivalent circuit diagram is as follows: Figure 8 As shown. In this case, the branches containing the fourth resistor R4 and the fifth resistor R5, as well as the branch containing the sixth resistor R6, are connected in parallel with the negative ground insulation resistance Rn.

[0158] It should be noted that when the second switch K2 is in the off state, the second sampling signal obtained by sampling can be the voltage across the battery pack; when the second switch K2 is in the on state, the negative voltage to ground is obtained by sampling. By multiplexing the second detection branch 102, the configuration of the insulation sampling circuit is reduced, thereby reducing the number of devices used and reducing the circuit complexity.

[0159] In some embodiments, the first switch branch 103 includes a fourth switch K4; wherein:

[0160] The first terminal of the fourth switch K4 is connected to the second terminal of the fifth resistor R5 and the first terminal of the sixth resistor R6, respectively.

[0161] The second terminal of the fourth switch K4 is grounded.

[0162] In this embodiment of the invention, when the fourth switch K4 is in the ON state, the first switch branch 103 is in the ON state; or, when the fourth switch K4 is in the OFF state, the first switch branch 103 is in the OFF state.

[0163] It should be noted that when the first switch K1, the second switch K2, and the third switch K3 are in different states, the connection path in the control circuit can change, the series and parallel relationship of the resistors in the insulation sampling circuit can change, and the voltage values ​​of the first sampling signal and the second sampling signal can change.

[0164] This utility model embodiment provides an insulation detection circuit. The first switch branch includes a fourth switch. By flexibly switching the sampling path, different second sampling signals can be obtained, thereby realizing the accurate solution of the positive to ground insulation resistance and the negative to ground insulation resistance.

[0165] In this embodiment of the utility model, based on Figures 6 to 8 The insulation sampling circuit shown can have a sampling process that includes two stages:

[0166] Phase 1: Controlling the first switch K1 and the third switch K3 to close, and the second switch K2 to close. Its equivalent circuit diagram is as follows: Figure 7 As shown above, in this case, the voltage Ubat across the battery pack is determined based on the first sampled signal, the voltage Up3 across the positive-to-ground insulation resistor Rp is determined based on the second sampled signal, and further, the voltage Un3 across the negative-to-ground insulation resistor Rn is determined to be Ubat - Up3. Based on... Figure 7 In the circuit structure shown, the branch containing the third resistor R3, the fourth resistor R4, and the fifth resistor R5 is connected in parallel with the positive ground insulation resistance Rp, and the sixth resistor R6 is connected in parallel with the negative ground insulation resistance Rn. Equation (3) can be obtained regarding the positive ground insulation resistance Rp and the negative ground insulation resistance Rn:

[0167] Up3 / Un3=Rp / / (R3+R4+R5) / Rn / / R6(3)

[0168] Second stage: Controlling the first switch K1, the second switch K2, and the third switch K3 to all close, the equivalent circuit diagram is as follows. Figure 8As shown. In this case, the voltage Ubat across the battery pack is determined based on the first sampled signal, the voltage Up4 across the positive-to-ground insulation resistor Rp is determined based on the second sampled signal, and further, the voltage Un4 across the negative-to-ground insulation resistor Rn is determined to be Ubat - Up4. Figure 8 In the circuit structure shown, the third resistor R3 is connected to the negative terminal of the battery pack through the second switch K2, breaking the parallel connection with the positive ground insulation resistor Rp. The branch containing the fourth resistor R4 and the fifth resistor R5 is connected to the negative terminal of the battery pack through the second switch K2, and is connected in parallel with the negative ground insulation resistor Rn. Since the resistances connected in parallel with the positive ground insulation resistor Rp and the negative ground insulation resistor Rn change, the voltage in the circuit will be redistributed, and the equation (4) regarding the positive ground insulation resistor Rp and the negative ground insulation resistor Rn can be obtained:

[0169] Up4 / Un4=Rp / Rn / / (R4+R5) / / R6(4)

[0170] In this embodiment of the utility model, by solving the above equations (3) and (4) simultaneously, the positive ground insulation resistance Rp and the negative ground insulation resistance Rn can be calculated and determined.

[0171] In another embodiment of this utility model, based on Figure 2 The illustrated embodiment, as Figure 9 As shown, the first detection branch 101 includes a seventh resistor R7, an eighth resistor R8, a ninth resistor R9, and a fifth switch K5; wherein:

[0172] The first terminal of the seventh resistor R7 is connected to the positive terminal of the battery pack, and the second terminal of the seventh resistor R7 is connected to the first terminal of the fifth switch K5.

[0173] The second terminal of the fifth switch K5 is connected to the first terminal of the second detection branch 102, the first terminal of the eighth resistor R8, and the first switch branch 103, respectively.

[0174] The second terminal of the eighth resistor R8 is connected to the first terminal of the ninth resistor R9;

[0175] The second terminal of the ninth resistor R9 is connected to the negative terminal of the battery pack and the second terminal of the second detection branch 102, respectively.

[0176] A fourth sampling point is set between the second end of the eighth resistor R8 and the first end of the ninth resistor R9. The fourth sampling point is used to sample at least one first sampling signal.

[0177] In this embodiment of the invention, when the fifth switch K5 is closed, the first detection branch 101 is in a conducting state, and the branches containing the positive-to-ground insulation resistance Rp and the negative-to-ground insulation resistance Rn of the first detection branch 101 are connected in parallel across the two ends of the battery pack. Alternatively, when the fifth switch K5 is closed, the first detection branch 101 is in a closed state.

[0178] Among them, the seventh resistor R7, the eighth resistor R8 and the ninth resistor R9 form a voltage divider path. A fourth sampling point is set between the eighth resistor R8 and the ninth resistor R9 to collect the first sampling signal when the fifth switch K5 is closed or when the fifth switch K5 is closed, so as to obtain at least one first sampling signal.

[0179] In this embodiment of the invention, the voltage across the negative ground insulation resistance Rn can be determined based on the first sampling signal collected at the fourth sampling point and the voltage division of the corresponding seventh resistor R7, eighth resistor R8 and ninth resistor R9.

[0180] In some embodiments, a fifth sampling point can be set at the first end of the seventh resistor R7, and a sixth sampling point can be set at the second end of the ninth resistor R9 to collect the first sampling signal respectively. When the first detection branch 101 and the second detection branch 102 are in different states, that is, when the insulation sampling circuit is in different stages, at least one first sampling signal (with a voltage value of U1) at the fifth sampling point and at least one first sampling signal (with a voltage value of U00) at the sixth sampling point are obtained, and the voltage across the battery pack is determined based on the first sampling signals collected at the fifth sampling point and the sixth sampling point in the same stage respectively.

[0181] This invention provides an insulation detection circuit. The first detection branch includes a seventh resistor, an eighth resistor, a ninth resistor, and a fifth switch. By dividing the voltage across the resistors and turning the fifth switch on or off, at least one first sampling signal is obtained, thereby determining the resistance value of the insulation resistor. This reduces the number of components used and lowers circuit costs while ensuring the accuracy of the insulation resistance.

[0182] In some embodiments, such as Figure 9 As shown, the second detection branch 102 includes a tenth resistor R10 and a sixth switch K6; wherein:

[0183] The first end of the sixth switch K6 is connected to the second end of the fifth switch K5, the first end of the eighth resistor R8 and the first switch branch 103 respectively, and the second end of the sixth switch K6 is connected to the first end of the tenth resistor R10.

[0184] The second terminal of the tenth resistor R10 is connected to the negative terminal of the battery pack and the second terminal of the ninth resistor R9, respectively.

[0185] In this embodiment of the invention, when the sixth switch K6 is in the ON state, the second detection branch 102 is in the ON state; when the sixth switch K6 is in the OFF state, the second detection branch 102 is in the OFF state.

[0186] In this embodiment of the invention, the series and parallel states of the resistors in the insulation detection circuit can be changed by controlling the conduction or cutoff of the sixth switch K6, thereby obtaining different first sampling signals.

[0187] For example, when the sixth switch K6 is in the on state and the fifth switch K5 is in the off state, the branch containing the tenth resistor R10, the branch containing the eighth resistor R8 and the ninth resistor R9 are connected in parallel with the negative ground insulation resistance Rn, and the first sampling signal is obtained by sampling the fourth sampling point, the fifth sampling point and the sixth sampling point respectively.

[0188] Alternatively, when the sixth switch K6 is in the off state and the fifth switch K5 is in the off state, the branch containing the eighth resistor R8 and the ninth resistor R9 is connected in parallel with the negative ground insulation resistance Rn, and the first sampling signal is obtained by sampling the fourth sampling point, the fifth sampling point and the sixth sampling point respectively.

[0189] Furthermore, based on the first sampling signals obtained under the above different states, the resistance values ​​of the positive-to-ground insulation resistance and the negative-to-ground insulation resistance are determined.

[0190] This invention provides an insulation detection circuit that, when the second detection branch and the first detection branch are in different states, acquires at least one first sampling signal. This first sampling signal is further used to determine the resistance value of the positive-to-ground insulation resistance and the resistance value of the negative-to-ground insulation resistance. Thus, accurate and efficient detection of the insulation resistance value is achieved with a simple circuit structure.

[0191] In some embodiments, such as Figure 9 As shown, the first switch branch 103 includes a seventh switch K7; wherein:

[0192] The first terminal of the seventh switch K7 is connected to the first terminal of the sixth switch K6, the first terminal of the eighth resistor R8, and the second terminal of the fifth switch K5, respectively.

[0193] The second terminal of the seventh switch K7 is grounded.

[0194] In this embodiment of the invention, when the seventh switch K7 is in the ON state, the first switch branch 103 is in the ON state; or, when the seventh switch K7 is in the OFF state, the first switch branch 103 is in the OFF state.

[0195] In this embodiment of the invention, by controlling the on and off of the seventh switch K7, the series and parallel relationships between resistors in the insulation detection circuit are controlled, and at least one first sampling signal is obtained by sampling under different connection relationships.

[0196] This utility model embodiment provides an insulation detection circuit that flexibly switches the sampling path by controlling the conduction or cutoff of the seventh switch to obtain different first sampling signals, thereby achieving accurate calculation of the positive-to-ground insulation resistance and the negative-to-ground insulation resistance.

[0197] In this embodiment of the utility model, based on Figure 9 The insulation sampling circuit shown can have a sampling process that includes two stages:

[0198] Phase 1: Control the fifth switch K5, the sixth switch K6, and the seventh switch K7 to conduct. In this case, the seventh resistor R7 is connected in parallel with the positive-to-ground insulation resistance Rp, and the branches containing the eighth resistor R8 and the ninth resistor R9, and the branch containing the tenth resistor R10, are connected in parallel with the negative-to-ground insulation resistance Rn. Based on the first sampling signals obtained from the fifth and sixth sampling points, the voltage Ubat across the battery pack is determined; based on the first sampling signal obtained from the fourth sampling point, the voltage Un5 across the negative-to-ground insulation resistance Rn is determined; further, the voltage Up5 across the positive-to-ground insulation resistance Rp is determined to be Ubat - Un5. Equation 5 can be constructed regarding the positive-to-ground insulation resistance Rp and the negative-to-ground insulation resistance Rn:

[0199] Up5 / Un5=Rp / / R7 / Rn / / (R8+R9) / / R10(5)

[0200] Second stage: Control the fifth switch K5 and the seventh switch K7 to turn on, and control the sixth switch K6 to turn off. In this case, the seventh resistor R7 is connected in parallel with the positive ground insulation resistance Rp, and the branch containing the eighth resistor R8 and the ninth resistor R9 is connected in parallel with the negative ground insulation resistance Rn. Based on the first sampling signal obtained from the fifth sampling point and the first sampling signal obtained from the sixth sampling point, the voltage Ubat across the battery pack is determined; based on the first sampling signal obtained from the fourth sampling point, the voltage Un6 across the negative ground insulation resistance Rn is determined; further, the voltage Up6 across the positive ground insulation resistance Rp is determined to be Ubat - Un6. Equation 6 can be constructed regarding the positive ground insulation resistance Rp and the negative ground insulation resistance Rn:

[0201] Up6 / Un6=Rp / / R7 / Rn / / (R8+R9)(6)

[0202] In this embodiment of the utility model, by solving the above equations (5) and (6) simultaneously, the positive ground insulation resistance Rp and the negative ground insulation resistance Rn can be calculated and determined.

[0203] In another embodiment of this utility model, a battery management system is provided, such as... Figure 10 As shown, the battery management system 20 includes a control branch 201 and an insulation detection circuit 10 as described in the previous embodiment, wherein the control branch 201 is connected to the insulation detection circuit 10; wherein:

[0204] Control branch 201 is used to determine the resistance value of the positive-to-ground insulation resistance and the resistance value of the negative-to-ground insulation resistance based on at least one first sampling signal and / or at least one second sampling signal acquired by the insulation detection circuit 10.

[0205] Currently, the insulation detection circuits used in related technologies are designed based on the balanced bridge method. This method not only uses a relatively large number of components but also has a high cost. How to reduce the cost of the circuit is an urgent problem to be solved.

[0206] In this embodiment of the utility model, based on Figures 3-5 The insulation sampling circuit shown can have a sampling process that includes two stages:

[0207] Phase 1: The control branch controls the first and third switches to close, and the second switch to close. Its equivalent circuit diagram is as follows: Figure 4 As shown. Based on the first sampled signal, the voltage Ubat across the battery pack is determined, and based on the second sampled signal, the voltage Un1 across the negative-to-ground insulation resistance is determined. Furthermore, the voltage Up1 across the positive-to-ground insulation resistance is determined to be Ubat - Un1. Equations for the positive-to-ground insulation resistance Rp and the negative-to-ground insulation resistance Rn can be obtained, as shown in the aforementioned equation (1).

[0208] Phase Two: The control branch controls the first, second, and third switches to all close. Its equivalent circuit diagram is as follows: Figure 5 As shown. In the first stage, the third resistor and the fourth resistor are connected in parallel with the positive-to-ground insulation resistance Rp; in the second stage, the third resistor is connected to the negative terminal of the battery pack through the second switch, breaking the parallel connection with the positive-to-ground insulation resistance Rp, and the fourth resistor is connected to the negative terminal of the battery pack through the second switch, connecting in parallel with the negative-to-ground insulation resistance Rn. Due to the change in the parallel resistance of the positive-to-ground insulation resistance Rp and the negative-to-ground insulation resistance Rn, the voltage in the circuit is redistributed, resulting in equations about the positive-to-ground insulation resistance Rp and the negative-to-ground insulation resistance Rn, as shown in the aforementioned equation (2).

[0209] Furthermore, the control branch acquires at least one first sampling signal and at least one second sampling signal obtained from the sampling at different stages mentioned above. By solving equations (1) and (2) simultaneously, the positive-to-ground insulation resistance Rp and the negative-to-ground insulation resistance Rn can be calculated and determined.

[0210] In another embodiment of this utility model, based on Figures 6-8 The insulation sampling circuit shown can have a sampling process that includes two stages:

[0211] Phase 1: The control branch controls the first and third switches to close, and the second switch to close. Its equivalent circuit diagram is as follows: Figure 7 As shown. Based on the first sampled signal, the voltage Ubat across the battery pack is determined, and based on the second sampled signal, the voltage Up3 across the positive ground insulation resistor is determined. Furthermore, the voltage Un3 across the negative ground insulation resistor is determined to be Ubat - Up3. Equations for the positive ground insulation resistor Rp and the negative ground insulation resistor Rn can be obtained, as shown in equation (3).

[0212] Phase Two: The control branch controls the first, second, and third switches to all close. Its equivalent circuit diagram is as follows: Figure 8 As shown. In the first stage, the branch containing the third, fourth, and fifth resistors is connected in parallel with the positive ground insulation resistance Rp; in the second stage, the third resistor is connected to the negative terminal of the battery pack through the second switch, breaking the parallel connection with the positive ground insulation resistance Rp, and the branch containing the fourth and fifth resistors is connected to the negative terminal of the battery pack through the second switch, connecting in parallel with the negative ground insulation resistance Rn. Due to the change in the parallel resistance of the positive ground insulation resistance Rp and the negative ground insulation resistance Rn, the voltage in the circuit is redistributed, resulting in the equations for the positive ground insulation resistance Rp and the negative ground insulation resistance Rn, as shown in the aforementioned equation (4).

[0213] In this embodiment of the utility model, the control branch can be calculated and determined by solving equations (3) and (4) of the above two stages simultaneously. The positive ground insulation resistance Rp and the negative ground insulation resistance Rn can be determined by solving the equations simultaneously.

[0214] Thus, in this embodiment of the invention, by reusing the relevant sampling circuit, the use of components in the insulation detection circuit is reduced, thereby lowering the cost and complexity of the circuit and improving its reliability.

[0215] In another embodiment of this utility model, a battery device 300 is provided, such as... Figure 11 As shown, the battery device 300 includes a battery 3001 and the battery management system 20 in the aforementioned embodiments.

[0216] The Battery Management System (BMS) 20 of this invention is used to perform at least one of the following functions: battery status monitoring, status analysis, charge / discharge control, safety protection, thermal management, high-voltage power distribution, and information management. In addition, the Battery Management System 20 of this invention can also perform the functions of a controller in an electrical device, such as a vehicle control unit (VCU) or a motor control unit (MCU), etc., and this invention does not impose any limitations on this.

[0217] It should be noted that the battery management system 20 in this utility model can be partially or entirely integrated into the battery device, such as into the battery pack or energy storage box.

[0218] The battery management system 20 of this utility model can be integrated into the power-consuming device in part or all, such as in a vehicle or vehicle chassis;

[0219] The battery management system 20 in this utility model can be partially or entirely integrated into the charging device, such as into the charging device or the battery swapping device.

[0220] The battery management system 20 in this invention can also be deployed as control software on a server. The server can be a standalone physical server, a server cluster or distributed system composed of multiple physical servers, or a cloud server that provides basic cloud computing services such as cloud services, cloud databases, cloud computing, cloud functions, cloud storage, network services, cloud communication, middleware services, domain name services, security services, CDN (Content Delivery Network), and big data and artificial intelligence platforms, such as vehicle networking cloud and APP backend.

[0221] In another embodiment of this utility model, an electrically driven device is provided, such as... Figure 12 As shown, the electric drive device 40 includes the battery device 300 in the aforementioned embodiments.

[0222] In this embodiment of the invention, the electric drive device 40 can be a battery-powered device containing a battery pack. Its internal battery management system can monitor the connection status of the battery pack to ensure the integrity of the high-voltage circuit between battery packs. For example, the electric drive device 40 can be a new energy vehicle, ship, aircraft, etc., or a power device such as an electric vehicle, hybrid vehicle, or electric motorcycle.

[0223] It should be understood that those skilled in the art will recognize that this invention may take the form of a hardware embodiment, a software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage and optical storage) containing computer-usable program code.

[0224] It should also be understood that the phrase "one embodiment" or "an embodiment" throughout the specification means that a specific feature, structure, or characteristic related to the embodiment is included in at least one embodiment of the present invention. Therefore, "in one embodiment" or "in an embodiment" appearing throughout the specification does not necessarily refer to the same embodiment. Furthermore, these specific features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. It should be understood that in the various embodiments of the present invention, the sequence number of the above-described steps / processes does not imply the order of execution; the execution order of each step / process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention. The above-described embodiment numbers are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0225] It should be noted that, in this utility model, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0226] In the several embodiments provided by this utility model, it should be understood that the disclosed systems, devices, and methods can be implemented in other ways. The device embodiments described above are merely illustrative. For example, the division of units is only a logical functional division, and in actual implementation, there may be other division methods, such as: multiple units or components can be combined, or integrated into another system, or some features can be ignored or not executed. In addition, the coupling, direct coupling, or communication connection between the various components shown or discussed can be through some interfaces, and the indirect coupling or communication connection between devices or units can be electrical, mechanical, or other forms.

[0227] The units described above as separate components may or may not be physically separate; the components shown as units may or may not be physical units; they may be located in one place or distributed across multiple network units; some or all of the units may be selected to achieve the purpose of this embodiment according to actual needs. Furthermore, in the various embodiments of this utility model, all functional units may be integrated into one processing unit, or each unit may be a separate unit, or two or more units may be integrated into one unit; the integrated unit may be implemented in hardware or in a combination of hardware and software functional units.

[0228] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the scope of protection of the present utility model. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present utility model should be included within the scope of protection of the present utility model.

Claims

1. An insulation detection circuit, characterized by comprising: The insulation detection circuit comprises a first detection branch, a second detection branch and a first switch branch; wherein: The first end of the first detection branch is connected with the positive terminal of the battery pack, and the second end of the first detection branch is connected with the first end of the second detection branch; the third end of the first detection branch is respectively connected with the negative terminal of the battery pack and the second end of the second detection branch; The first switch branch is connected with the third end of the second detection branch, or the first switch branch is connected between the second end of the first detection branch and the first end of the second detection branch; The insulation detection circuit is used to acquire at least one first sampling signal provided by the first detection branch and / or at least one second sampling signal provided by the second detection branch in the case that the first detection branch, the second detection branch and the first switch branch are in different states. The at least one first sampling signal and / or the at least one second sampling signal are used to determine the resistance value of the positive-to-ground insulation resistance and the resistance value of the negative-to-ground insulation resistance.

2. The insulation detection circuit according to claim 1, characterized by The first detection branch comprises a first resistor, a second resistor and a first switch; wherein: The first end of the first resistor is respectively connected with the positive terminal of the battery pack and the first end of the second detection branch, and the second end of the first resistor is connected with the first end of the first switch; The second end of the first switch is connected with the first end of the second resistor, and the second end of the second resistor is respectively connected with the negative terminal of the battery pack and the second end of the second detection branch; A first sampling point is arranged between the second end of the first switch and the first end of the second resistor, and the first sampling point is used to sample the at least one first sampling signal.

3. The insulation detection circuit according to claim 1, characterized by The second detection branch comprises a first voltage division branch and a second switch branch; wherein: The first end of the first voltage division branch is connected with the positive terminal of the battery pack and the first end of the first detection branch, and the second end of the first voltage division branch is respectively connected with the negative terminal of the battery pack, the second end of the first detection branch and the second end of the second switch branch; The first end of the second switch branch is connected with the third end of the first voltage division branch.

4. The insulation detection circuit according to claim 3, characterized in that, The first voltage division branch comprises a third resistor, a fourth resistor, a fifth resistor and a sixth resistor; wherein: The first end of the third resistor is connected with the positive terminal of the battery pack and the first end of the first detection branch, and the second end of the third resistor is respectively connected with the first end of the fourth resistor and the first end of the second switch branch; The second end of the fourth resistor is connected with the first end of the fifth resistor; The second end of the fifth resistor is connected with the first end of the sixth resistor; The second end of the sixth resistor is respectively connected with the negative terminal of the battery pack, the second end of the first detection branch and the second end of the second switch branch.

5. The insulation detection circuit according to claim 4, characterized in that, The second switch branch comprises a second switch; wherein: The first end of the second switch is respectively connected with the second end of the third resistor and the first end of the fourth resistor, and the second end of the second switch is respectively connected with the second end of the sixth resistor, the negative terminal of the battery pack and the second end of the first detection branch.

6. The insulation detection circuit according to claim 4, characterized by The first switch branch includes a third switch; wherein: The first end of the third switch is connected with the second end of the fourth resistor and the first end of the fifth resistor, respectively; The second end of the third switch is grounded.

7. The insulation detection circuit according to claim 6, characterized in that, A second sampling point is arranged between the second end of the fifth resistor and the first end of the sixth resistor, and the second sampling point is used for sampling the at least one second sampling signal.

8. The insulation detection circuit according to claim 4, characterized by The first switch branch includes a fourth switch; wherein: The first end of the fourth switch is connected with the second end of the fifth resistor and the first end of the sixth resistor, respectively; The second end of the fourth switch is grounded.

9. The insulation detection circuit according to claim 8, characterized in that, A third sampling point is arranged between the second end of the fourth resistor and the first end of the fifth resistor, and the third sampling point is used for sampling the at least one second sampling signal.

10. The insulation detection circuit of claim 1, wherein The first detection branch includes a seventh resistor, an eighth resistor, a ninth resistor and a fifth switch; wherein: The first end of the seventh resistor is connected with the positive electrode end of the battery pack, and the second end of the seventh resistor is connected with the first end of the fifth switch; The second end of the fifth switch is connected with the first end of the second detection branch, the first end of the eighth resistor and the first switch branch, respectively; The second end of the eighth resistor is connected with the first end of the ninth resistor; The second end of the ninth resistor is connected with the negative electrode end of the battery pack and the second end of the second detection branch, respectively; A fourth sampling point is arranged between the second end of the eighth resistor and the first end of the ninth resistor, and the fourth sampling point is used for sampling the at least one first sampling signal.

11. The insulation detection circuit according to claim 10, characterized in that, The second detection branch includes a tenth resistor and a sixth switch; wherein: The first end of the sixth switch is connected with the second end of the fifth switch, the first end of the eighth resistor and the first switch branch, respectively, and the second end of the sixth switch is connected with the first end of the tenth resistor; The second end of the tenth resistor is connected with the negative electrode end of the battery pack and the second end of the ninth resistor, respectively.

12. The insulation detection circuit of claim 11, wherein The first switch branch includes a seventh switch; wherein: The first end of the seventh switch is connected with the first end of the sixth switch, the first end of the eighth resistor and the second end of the fifth switch, respectively; The second end of the seventh switch is grounded.

13. A battery management system, characterized by, The battery management system includes a control branch and the insulation detection circuit according to any one of claims 1-12, and the control branch is connected with the insulation detection circuit; wherein: The control branch is used for determining the resistance values of the positive-to-ground insulation resistance and the negative-to-ground insulation resistance based on the at least one first sampling signal and / or the at least one second sampling signal obtained by the insulation detection circuit.

14. A battery device characterized by comprising: Comprise: A battery and the battery management system according to claim 13.

15. An electric drive device, characterized by The electric drive device includes the battery device according to claim 14.

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