Control method and device of power battery protection circuit, chip and vehicle

Abstract

The application discloses a control method and device of a power battery protection circuit, a chip and a vehicle. The method comprises the following steps: acquiring a first voltage corresponding to a target current loop in n current loops under the condition that a main loop of a power battery is turned on, the target current loop being a current loop marked as an effective state; determining a current flowing through a shunt module based on the first voltage corresponding to the target current loop; and detecting whether a wire breaking event occurs in the target current loop based on the current flowing through the shunt module. The technical scheme provided in the application embodiment can perform real-time wire breaking detection on the target current loop marked as the effective state when the main loop of the power battery is turned on, can timely detect whether a sampling wire is broken, avoids the situation that the working current of the main loop of the power battery cannot be monitored due to untimely sampling wire breaking detection, and effectively protects the working safety of the power battery.

Description

Technical Field

[0001] This application relates to the field of power battery technology, and in particular to a control method, device, chip, and vehicle for a power battery protection circuit. Background Technology

[0002] Power batteries are the core components of new energy vehicles. To ensure the safe operation of power batteries, corresponding overcurrent protection circuits are usually designed for them.

[0003] Reference Figure 1 The diagram shows a circuit diagram of a power battery protection circuit 100 provided by related technologies. A fuse module 110 and a shunt module 120 are connected in series in the main circuit 200 of the power battery. The fuse module 110 and the shunt module 120 are respectively connected to an analog front end (AFE) chip 130. The AFE chip 130 detects the operating current of the main circuit 200 of the power battery by measuring the voltage across the shunt module 120. When the operating current of the main circuit 200 of the power battery exceeds the safe current threshold, it controls the fuse module 110 to blow up the main circuit 200 of the power battery.

[0004] However, the relevant technology has the following problem: if the sampling line between the AFE chip 130 and the shunt module 120 is broken, the voltage measured by the AFE chip 130 will be too high, which is consistent with the short circuit phenomenon in the main circuit 200 of the power battery. This will cause the AFE chip 130 to accidentally blow the fuse module, thereby cutting off the main circuit 200 of the power battery. Summary of the Invention

[0005] This application proposes a control method, device, chip, and vehicle for a power battery protection circuit.

[0006] In a first aspect, embodiments of this application provide a control method for a power battery protection circuit. The power battery protection circuit includes a shunt module, a current sampling module, n capacitor units, and n resistor units. The shunt module is connected to the main circuit of the power battery. n current loops are formed between the shunt module and the current sampling module. Each current loop includes a first sampling line and a second sampling line. The capacitor units are connected between the first and second sampling lines, and the resistor units are connected between the first and second sampling lines. n is an integer greater than 1. The method includes: when the main circuit of the power battery is conducting, acquiring a first voltage corresponding to a target current loop among the n current loops, where the target current loop is a current loop marked as valid; determining the current flowing through the shunt module based on the first voltage corresponding to the target current loop; detecting whether a disconnection event has occurred in the target current loop based on the current flowing through the shunt module, where a disconnection event refers to the disconnection of the first sampling line included in the target current loop; and / or, the disconnection of the second sampling line included in the target current loop.

[0007] Secondly, embodiments of this application provide a control device for a power battery protection circuit. The power battery protection circuit includes a shunt module, a current sampling module, n capacitor units, and n resistor units. The shunt module is connected to the main circuit of the power battery. n current loops are formed between the shunt module and the current sampling module. Each current loop includes a first sampling line and a second sampling line. The capacitor units are connected between the first and second sampling lines, and the resistor units are connected between the first and second sampling lines. n is an integer greater than 1. The device includes: a voltage acquisition unit, used to acquire a first voltage corresponding to a target current loop among the n current loops when the main circuit of the power battery is conducting. The target current loop refers to a current loop marked as valid. A current determination unit, used to determine the current flowing through the shunt module based on the first voltage corresponding to the target current loop. A disconnection event detection unit, used to detect whether a disconnection event has occurred in the target current loop based on the current flowing through the shunt module. A disconnection event refers to the disconnection of the first sampling line included in the target current loop; and / or, the disconnection of the second sampling line included in the target current loop.

[0008] Thirdly, embodiments of this application provide a chip, the chip including: a processor; a memory; one or more application programs, wherein the one or more application programs are stored in the memory and configured to be executed by the one or more processors, and the one or more application programs are configured to perform the method as described in the first aspect.

[0009] Fourthly, this application provides a vehicle, which includes: a main circuit of a power battery; a power battery protection circuit; the power battery protection circuit includes a shunt module, a current sampling module, n capacitor units, and n resistor units; the shunt module is connected to the main circuit of the power battery; n current loops are formed between the shunt module and the current sampling module, the current loops include a first sampling line and a second sampling line, the capacitor units are connected between the first sampling line and the second sampling line, the resistor units are connected between the first sampling line and the second sampling line, and n is an integer greater than 1.

[0010] Fifthly, embodiments of this application provide a computer-readable storage medium storing program code, which is invoked by a processor to execute the method as described in the second aspect.

[0011] In a sixth aspect, embodiments of this application provide a computer program product that, when executed, is used to implement the method as described in the second aspect.

[0012] Compared to existing technologies, the technical solution provided in this application adds a capacitor unit and a resistor unit between the first and second sampling lines of the current loop. On the one hand, since the voltage between the capacitor units does not change instantaneously, the voltage between the first and second sampling lines remains constant for a period of time. On the other hand, the resistor unit can discharge the energy of the capacitor unit, so that when the first or second sampling line is disconnected, the detection voltage obtained by the current sampling module is clamped at around 0V, avoiding the situation where the detection voltage obtained by the current sampling module is too large when the sampling line is disconnected, which may cause the fuse module to be falsely triggered. Furthermore, since the current sampling module will not falsely trigger the fuse module when the sampling line is disconnected, the current sampling module can perform real-time disconnection detection on the target current loop marked as valid when the main circuit of the power battery is conducting. It can detect whether the sampling line is disconnected in time, avoiding the situation where the working current of the main circuit of the power battery cannot be monitored due to the untimely detection of the sampling line disconnection, effectively protecting the working safety of the power battery. Attached Figure Description

[0013] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0014] Figure 1 This is a circuit diagram of a power battery protection circuit provided by relevant technologies.

[0015] Figure 2This is a circuit diagram of the main circuit of a power battery provided in one embodiment of this application.

[0016] Figure 3 This is a circuit diagram of a power battery protection circuit provided in one embodiment of this application.

[0017] Figure 4 This is a schematic diagram of a vehicle provided in one embodiment of this application.

[0018] Figure 5 This is a flowchart of a control method for a power battery protection circuit provided in one embodiment of this application.

[0019] Figure 6 This is a flowchart of a control method for a power battery protection circuit provided in another embodiment of this application.

[0020] Figure 7 This is a flowchart of a control method for a power battery protection circuit provided in another embodiment of this application.

[0021] Figure 8 This is a flowchart of a control method for a power battery protection circuit provided in another embodiment of this application.

[0022] Figure 9 This is a block diagram of a control device for a power battery protection circuit provided in one embodiment of this application.

[0023] Figure 10 This is a structural block diagram of a chip provided in one embodiment of this application.

[0024] Figure 11 This is a structural block diagram of a computer-readable storage medium provided in one embodiment of this application. Detailed Implementation

[0025] The embodiments of this application are described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0026] To enable those skilled in the art to better understand the solutions of this application, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0027] After long-term research, the inventors discovered the following defects in the power battery protection circuit provided by the relevant technology: First, if the sampling line between the AFE chip 130 and the shunt module 120 is broken, the voltage measured by the AFE chip 130 will be too high, which is consistent with the short circuit phenomenon in the main circuit 200 of the power battery. This will cause the AFE chip 130 to accidentally detonate the fuse module, thereby cutting off the main circuit 200 of the power battery; Second, if the sampling line between the AFE chip 130 and the shunt module 120 is broken, the AFE chip 130 cannot monitor the operating current of the main circuit 200 of the power battery, resulting in the inability to provide overcurrent protection for the power battery.

[0028] Based on the shortcomings of related technologies, the inventors designed a new power battery protection circuit. Firstly, multiple current loops are set between the shunt module and the battery sampling module to form redundancy. Even if one current loop experiences a disconnection, the operating current of the main circuit of the power battery can still be monitored through other current loops. Secondly, a capacitor unit and a resistor unit are added between the first and second sampling lines of the current loop. On the one hand, since the voltage between the capacitor units does not change instantaneously, the voltage between the first and second sampling lines remains constant for a period of time. On the other hand, the resistor unit can discharge the energy of the capacitor unit, so that when either the first or second sampling line disconnects, the detection voltage obtained by the current sampling module is clamped to around 0V, preventing the current sampling module from mistakenly triggering the fuse module due to an excessively high detection voltage when the sampling line disconnects. Based on the aforementioned power battery protection circuit, the inventors also designed a control method for the power battery protection circuit. Since the current sampling module will not accidentally trigger the fuse module when the sampling line is disconnected, the current sampling module can perform real-time disconnection detection on the target current loop marked as valid when the main circuit of the power battery is conducting. This can detect whether the sampling line is disconnected in a timely manner, avoiding the situation where the working current of the main circuit of the power battery cannot be monitored due to the failure to detect the sampling line disconnection in a timely manner, and effectively protecting the working safety of the power battery.

[0029] First, the technical terms provided in the embodiments of this application will be introduced.

[0030] The main circuit 200 of the power battery 210 refers to the circuit in which the power battery 210 supplies power to various loads. (Refer to the reference.) Figure 2The diagram shows the circuit diagram of the main circuit 200 of the power battery 210. The main circuit 200 of the power battery 210 includes the power battery 210, a first relay 220, and a second relay 230. The first relay 220 is a positive relay connected to the positive terminal of the power battery 210. The second relay 230 is a negative relay connected to the negative terminal of the power battery 210. When both the first relay 220 and the second relay 230 are closed, the main circuit 200 of the power battery 210 is conductive; when both the first relay 220 and the second relay 230 are open, the main circuit 200 of the power battery 210 is disconnected.

[0031] Please refer to Figure 3 The diagram illustrates the circuit structure of a power battery protection circuit 300 according to an embodiment of this application. The power battery protection circuit 300 includes a shunt module 310, a current sampling module 320, n capacitor units 330, and n resistor units 340, where n is an integer greater than 1.

[0032] The shunt module 310 is connected to the main circuit 200 of the power battery 210. Specifically, the shunt module 310 is connected in series in the main circuit 200 of the power battery 210. The shunt module 310 is used to shunt current into the main circuit 200 of the power battery 210. In some embodiments, the shunt module 310 is a resistor at the μΩ level.

[0033] The current sampling module 320 is used to detect the voltage across the shunt module 310. Given the known resistance of the shunt module 310, the current flowing through the shunt module 310, which is also the operating current of the main circuit 200 of the power battery 210, can be calculated according to Ohm's law. In some embodiments, the current sampling module 320 is an AFE chip.

[0034] There are n current loops between the current sampling module 320 and the shunt module 310. These multiple current loops provide redundant backup for detecting the operating current of the main circuit 200 of the power battery 210. Even if one current loop is accidentally disconnected (e.g., the sampling line of that current loop is broken), the operating current of the main circuit 200 of the power battery 210 can still be detected through other current loops. The number of current loops is set based on experiments or experience, for example, two.

[0035] The current loop includes a first sampling line 350 and a second sampling line 360. The first sampling line 350 is connected to the positive terminal of the current sampling module 320 and one side of the shunt module 310, and the second sampling line 360 ​​is connected to the negative terminal of the current sampling module 320 and the other side of the shunt module 310.

[0036] A capacitor unit 330 is connected between the first sampling line 350 and the second sampling line 360. In the event of a break in either the first sampling line 350 or the second sampling line 360, the detection voltage obtained by the current sampling module 320 will be abnormally high, consistent with a short circuit in the main circuit 200 of the power battery 210. In this case, the current sampling module 320 will control the fuse module on the main circuit 200 of the power battery 210 to blow the main circuit 200. To avoid this situation, a capacitor unit 330 is added between the first sampling line 350 and the second sampling line 360. Since the voltage between the capacitor units 330 does not change instantaneously, the voltage between the first sampling line 350 and the second sampling line 360 ​​can be maintained within its original range for a period of time. The capacitor unit 330 may include one or more differential capacitors. When the capacitor unit 330 includes multiple differential capacitors, these multiple differential capacitors can be connected in parallel or in series; this embodiment does not limit this. In some embodiments, the equivalent capacitance of the capacitor unit 330 is approximately 220nF.

[0037] Resistor unit 340 is connected between the first sampling line 350 and the second sampling line 360. Resistor unit 340 is used to discharge the energy of capacitor unit 330, so that in the event of a break in the first sampling line 350 or the second sampling line 360, the detection voltage obtained by the current sampling module 320 is clamped to approximately 0V, preventing the current sampling module 320 from falsely triggering the aforementioned fuse module due to a break in the sampling line. Resistor unit 340 may include one or more differential resistors. When resistor unit 360 includes multiple differential resistors, these resistors can be connected in parallel or in series; this embodiment does not limit this. In some embodiments, the equivalent capacitance of resistor unit 360 is approximately 10kΩ.

[0038] In some embodiments, the power battery protection circuit 300 further includes a fuse module 370, which is connected in series in the main circuit 200 of the power battery 210 and connected to the current sampling module 320. The current sampling module 320 can acquire the voltage across the shunt module 310 and calculate the operating current of the main circuit 200 of the power battery 210 based on the voltage. When the operating current exceeds the safe current threshold, the fuse module 370 is controlled to blow the main circuit 200 of the power battery 210, thereby preventing the power battery 210 from burning out due to excessive instantaneous current.

[0039] Please refer to Figure 4 This application shows a schematic diagram of a vehicle 400. The vehicle 400 includes a battery management module, a main circuit for the power battery, a power battery protection circuit, a central control module, and multiple loads.

[0040] The power battery protection circuit includes a shunt module, a current sampling module, n capacitor units, and n resistor units. The shunt module is connected to the main circuit of the power battery. n current loops are formed between the shunt module and the current sampling module. Each current loop includes a first sampling line and a second sampling line. The capacitor units are connected between the first and second sampling lines, and the resistor units are also connected between the first and second sampling lines. n is an integer greater than 1.

[0041] The battery management module is connected to the main circuit of the power battery, the current sampling module, and the central control module, respectively. Multiple loads are connected to the main circuit of the power battery. These multiple loads can be braking systems, drive systems, radar systems, etc., and this application embodiment does not limit them.

[0042] Please refer to Figure 5 This illustrates a control method for a power battery protection circuit according to an embodiment of this application. This method is applied to the aforementioned power battery protection circuit. The execution entity for each step in this method is... Figure 3 The current sampling module 320 in the method includes the following procedures.

[0043] S501, when the main circuit of the power battery is turned on, the current sampling module obtains the first voltage corresponding to the target current circuit among n current circuits.

[0044] Combination Figure 2 In the example, when both the first relay 220 and the second relay 230 are closed, the main circuit of the power battery is turned on. A target current loop refers to a current loop that is marked as active. The number of target current loops is greater than or equal to 1 and less than or equal to n.

[0045] Optionally, the current sampling module includes status flag bits corresponding to n current loops. When the status flag bit corresponding to a current loop takes the first value, it indicates that the current loop is marked as valid; when the status flag bit corresponding to a current loop takes the second value, it indicates that the current loop is marked as invalid. The first and second values ​​are set based on experiments or experience, for example, the first value is 1 and the second value is 0.

[0046] In some embodiments, when the main circuit of the power battery is disconnected, the current sampling module detects whether a disconnection event has occurred in each of the n current circuits, and assigns values ​​to the status flag bits corresponding to the n current circuits based on the detection results. Specifically, when the main circuit of the power battery is disconnected, if the current sampling module detects that no disconnection event has occurred in a certain current circuit, it assigns the value of the status flag bit corresponding to that current circuit to the first value; if it detects that a disconnection event has occurred in a certain current circuit, it assigns the value of the status flag bit corresponding to that current circuit to the second value. The specific detection process will be described in the embodiments below.

[0047] The first voltage corresponding to the target current loop refers to the voltage on both sides of the shunt module in the target current loop.

[0048] S502 obtains the current flowing through the shunt module based on the first voltage corresponding to the target current loop.

[0049] The current sampling module can calculate the current flowing through the shunt module based on the following formula: I = U / R. Where U is the first voltage corresponding to the target current loop, and R is the resistance value of the shunt module.

[0050] When the target current circuit is working normally, the current flowing through the shunt module is also the operating current of the main circuit of the power battery.

[0051] S503 detects whether a break-in event has occurred in the target current loop based on the current flowing through the shunt module.

[0052] A disconnection event refers to the disconnection of the first sampling line included in the target current loop; and / or, the disconnection of the second sampling line included in the target current loop.

[0053] In the power battery protection circuit provided in this application embodiment, a capacitor unit and a resistor unit are added between the first sampling line and the second sampling line of the current loop. On the one hand, since the voltage between the capacitor units does not change instantaneously, the voltage between the first sampling line and the second sampling line remains unchanged for a period of time. On the other hand, the resistor unit can discharge the energy of the capacitor unit, so that when the first sampling line or the second sampling line is disconnected, the detection voltage obtained by the current sampling module is clamped at about 0V, avoiding the situation where the detection voltage obtained by the current sampling module is too large when the sampling line is disconnected, which may cause the fuse module to be falsely triggered.

[0054] Furthermore, since the current sampling module will not accidentally trigger the fuse module when the sampling line is broken, it can perform real-time disconnection detection on the target current loop marked as valid when the main circuit of the power battery is conducting. For example, if there are multiple target current loops and all of them are working normally, the current values ​​corresponding to the multiple target current loops are approximately the same. Based on this principle, the current sampling module can detect whether a disconnection event has occurred in the target current loop. Similarly, if the power battery is under a specified operating condition with a constant current value and the target current loop is working normally, the current value corresponding to the target current loop is approximately the same as the constant current value. Based on this principle, the current sampling module can also detect whether a disconnection event has occurred in the target current loop. These two disconnection detection methods will be discussed below. Figure 5 and Figure 6 The examples are described below.

[0055] In some embodiments, if the current flowing through the shunt module exceeds a safe current threshold, the fuse module is controlled to blow the main circuit of the power battery. When the target current circuit is operating normally, the current flowing through the shunt module is also the operating current of the main circuit of the power battery. The safe current threshold is set based on experiments or experience. In this embodiment, the current sampling module controls the fuse module to blow the main circuit of the power battery when the current flowing through the shunt module exceeds the safe current threshold, thereby achieving overcurrent protection for the power battery.

[0056] In summary, the technical solution provided in this application adds a capacitor unit and a resistor unit between the first and second sampling lines of the current loop. On the one hand, since the voltage between the capacitor units does not change instantaneously, the voltage between the first and second sampling lines remains constant for a period of time. On the other hand, the resistor unit can discharge the energy of the capacitor unit, so that when either the first or second sampling line is disconnected, the detection voltage obtained by the current sampling module is clamped to around 0V, avoiding the situation where the detection voltage obtained by the current sampling module is too high when the sampling line is disconnected, which could lead to the accidental triggering of the fuse module. Furthermore, since the current sampling module will not accidentally trigger the fuse module when the sampling line is disconnected, the current sampling module can perform real-time disconnection detection on the target current loop marked as valid when the main circuit of the power battery is conducting. It can detect whether a sampling line disconnection has occurred in a timely manner, avoiding the situation where the operating current of the main circuit of the power battery cannot be monitored due to untimely detection of sampling line disconnection, thus effectively protecting the operating safety of the power battery.

[0057] The following describes the open circuit detection method when the target current loop includes both a first current loop and a second current loop. Based on... Figure 5 In the optional embodiments provided by the examples, S503 is replaced by S603-S605.

[0058] Please refer to Figure 6 This illustrates a flowchart of a control method for a power battery protection circuit according to another embodiment of this application. The execution entity for each step in this method is... Figure 3 The current sampling module 320 in the method includes the following procedures.

[0059] S601, when the main circuit of the power battery is turned on, the current sampling module obtains the first voltage corresponding to the target current circuit among n current circuits.

[0060] The target current loop refers to the current loop that is marked as being in an active state.

[0061] S602 determines the current flowing through the shunt module based on the first voltage corresponding to the target current loop.

[0062] S603, when the target current loop includes a first current loop and a second current loop, obtain the first difference between the first current and the second current.

[0063] The first current refers to the current flowing through the shunt module, determined based on the first voltage corresponding to the first current loop. The second current refers to the current flowing through the shunt module, determined based on the first voltage corresponding to the second current loop. The calculation methods for the first and second currents can be found in S502, and will not be elaborated here.

[0064] S604, if the first difference is greater than the first error threshold, determine that a disconnection event has occurred in the first current loop or the second current loop.

[0065] The first error threshold is set based on experiments or experience, and this application embodiment does not limit it. When both the first current loop and the second current loop are working normally, the first current and the second current are both the working current of the main circuit of the power battery, and ideally they should be the same. Considering the difference between the sampling lines included in the first current loop and the sampling lines included in the second current loop, although the first current and the second current are not the same, the difference between them will be small. Therefore, by reasonably setting the first error threshold, it is possible to determine whether a disconnection event has occurred in the first current loop and the second current loop.

[0066] Furthermore, if a disconnection event occurs in the first current loop, the first current will be approximately zero, while the second current is the operating current of the main circuit of the power battery, and the first current is less than the second current. Similarly, if a disconnection event occurs in the second current loop, the second current will be approximately zero, while the first current is the operating current of the main circuit of the power battery, and the second current is less than the first current. Based on this principle, the current sampling module can further determine whether a disconnection event occurred in the first or second current loop. Specifically, if the first difference is greater than a first error threshold and the first current is less than the second current, a disconnection event is determined to have occurred in the first current loop; if the first difference is greater than the first error threshold and the first current is greater than the second current, a disconnection event is determined to have occurred in the second current loop.

[0067] S605, if the first difference is less than or equal to the first error threshold and the first current is greater than the preset current, or if the first difference is less than or equal to the first error threshold and the second current is greater than the preset current, it is determined that no disconnection event has occurred in the target current loop.

[0068] The preset current is set based on experiments or experience, and it is greater than zero and less than the current safety threshold. In this embodiment, after determining that the first difference between the first current and the second current is less than or equal to the first error threshold, the preset current is used for further judgment to avoid misjudgment when both the first current loop and the second current loop are disconnected.

[0069] In summary, the technical solution provided in this application, when the target current loop includes a first current loop and a second current loop, acquires the first current and the second current respectively, and then detects whether a disconnection event has occurred based on the first difference between the first current and the second current. Since the first difference is approximately zero when both the first current loop and the second current loop are working normally, based on the above principle, the current sampling module can detect whether a sampling line disconnection has occurred in a timely and accurate manner when the main circuit of the power battery is conducting, avoiding the situation where the working current of the main circuit of the power battery cannot be monitored due to the untimely detection of the sampling line disconnection, and effectively protecting the working safety of the power battery.

[0070] The following describes the method for detecting the open circuit of the target current loop when the power battery is under specified operating conditions. Based on... Figure 4 In the optional embodiments provided by the examples, S503 is replaced by S703-S706.

[0071] Please refer to Figure 7 This illustrates a flowchart of a control method for a power battery protection circuit according to another embodiment of this application. The execution entity for each step in this method is... Figure 3The current sampling module 320 in the method includes the following procedures.

[0072] S701, when the main circuit of the power battery is turned on, the current sampling module obtains the first voltage corresponding to the target current circuit among n current circuits.

[0073] The target current loop refers to the current loop that is marked as being in an active state.

[0074] S702 determines the current flowing through the shunt module based on the first voltage corresponding to the target current loop.

[0075] S703 obtains the operating current of the main circuit of the power battery under specified operating conditions.

[0076] The operating current of the main circuit of the power battery is a constant value under specified operating conditions. Specified operating conditions include pre-charge condition, waiting-to-charge condition, etc. Taking the pre-charge condition as an example, if the voltage of the power battery is 240V and the resistance is 30Ω, then the operating current of the main circuit of the power battery under specified operating conditions is 8A.

[0077] S704 obtains the second difference between the current flowing through the shunt module and the operating current of the main circuit of the power battery under specified operating conditions.

[0078] S705, if the second difference is greater than the second error threshold, determine that a break-in event has occurred in the target current loop.

[0079] The second error threshold is set based on experiments or experience, and this application embodiment does not limit it. As mentioned in the above embodiment, when the target current circuit is working normally, the current flowing through the shunt module is also the working current of the main circuit of the power battery. Since the working current of the main circuit of the power battery is constant under specified operating conditions, the second difference is approximately zero. Therefore, by reasonably setting the second error threshold, it is possible to determine whether a disconnection event has occurred in the target current circuit.

[0080] S706, if the second difference is less than or equal to the second error threshold, determine that no open circuit event has occurred in the target current loop.

[0081] In summary, the technical solution provided in this application, when the power battery is under specified operating conditions, allows the current sampling module to obtain a second difference between the current flowing through the shunt module and the operating current of the main circuit of the power battery under specified operating conditions. This second difference is then used to detect whether a disconnection event has occurred. Since the current flowing through the shunt module should be equal to the operating current of the main circuit of the power battery under specified operating conditions when the power battery is under specified operating conditions and the target current circuit is working normally, the second difference is approximately zero. Based on this principle, the current sampling module can detect whether a sampling line disconnection has occurred promptly and accurately when the main circuit of the power battery is conducting, avoiding the situation where the operating current of the main circuit of the power battery cannot be monitored due to untimely detection of sampling line disconnection, thus effectively protecting the operational safety of the power battery.

[0082] The method for determining the target current loop is described below. Please refer to... Figure 8 This document illustrates a flowchart of a control method for a power battery protection circuit according to an embodiment of this application. The execution entity for each step in this method is... Figure 3 The current sampling module 320 in the method includes the following procedures.

[0083] S801: When the main circuit of the power battery is disconnected, the current sampling module sends a disconnection detection signal to the shunt module.

[0084] When the main circuit of the power battery is disconnected, the current flowing through the shunt module is also zero, so a disconnection detection signal needs to be sent to the shunt module. This disconnection detection signal can be a sampled current.

[0085] S802, the current sampling module acquires the second voltage corresponding to each of the n current loops under the open circuit detection signal.

[0086] The second voltage corresponding to the current loop is the voltage on both sides of the shunt module in the current loop.

[0087] The S803 current sampling module detects whether a break-in event has occurred in the current loop based on the second voltage corresponding to the current loop.

[0088] Under normal operating conditions of the current loop, the aforementioned second voltage is the product of the sampling current and the resistance of the shunt module. Since the resistance of the shunt module is very small, the second voltage is very small, approximately zero. When a current loop disconnection event occurs, the corresponding second voltage of the current loop should be infinite. Based on the above principle, the current sampling module can detect whether a current loop disconnection event has occurred. Specifically, if the difference between the second voltage corresponding to the current loop and the first specified voltage is less than or equal to the third error threshold, it is determined that no current loop disconnection event has occurred; if the second voltage corresponding to the current loop is greater than the second specified voltage, it is determined that a current loop disconnection event has occurred.

[0089] The first specified voltage is set based on experiments or experience, such as 0V. The third error threshold is set based on experiments or experience, and this application does not limit this. The second specified voltage is set based on experiments or experience; for example, the second specified voltage can be the product of the safe current threshold of the main circuit of the power battery and the resistance of the shunt module. The first specified voltage is less than the second specified voltage.

[0090] S804, the current sampling module marks current loops that have not experienced a disconnection event as valid.

[0091] Optionally, the current sampling module assigns a first value to the status flag bit corresponding to the current loop where no open circuit event has occurred, and assigns a second value to the status flag bit corresponding to the current loop where an open circuit event has occurred.

[0092] In some embodiments, the current sampling module is also connected to the battery management module. The battery sampling module can send a disconnection detection result to the battery management module, which indicates whether a disconnection event has occurred in any of the n current loops. After obtaining the disconnection detection result, if the disconnection detection result indicates that at least one current loop has not experienced a disconnection event, the battery management module can control the first and second relays to close to conduct the main circuit of the power battery. If the disconnection detection result indicates that all current loops have experienced a disconnection event, the main circuit of the power battery is not conducted, and a reminder message is sent to the central control module to remind the user to perform timely vehicle maintenance.

[0093] S805, when the main circuit of the power battery is turned on, the current sampling module obtains the first voltage corresponding to the target current loop among n current loops.

[0094] The target current loop refers to the current loop that is marked as being in an active state.

[0095] S806 determines the current flowing through the shunt module based on the first voltage corresponding to the target current loop.

[0096] S807 detects whether a disconnection event has occurred in the target current loop based on the current flowing through the shunt module. A disconnection event refers to the disconnection of the first sampling line included in the target current loop; and / or, the disconnection of the second sampling line included in the target current loop.

[0097] In summary, the technical solution provided in this application embodiment performs open circuit detection on each current circuit before the main circuit of the power battery is turned on, and reports the open circuit detection results to the battery management module so that the battery management module can take reasonable measures based on the open circuit detection results.

[0098] Please refer to Figure 9 This diagram illustrates the structural block diagram of a control device for a power battery protection circuit according to an embodiment of this application. The power battery protection circuit includes a shunt module, a current sampling module, n capacitor units, and n resistor units. The shunt module is connected to the main circuit of the power battery. n current loops are formed between the shunt module and the current sampling module. Each current loop includes a first sampling line and a second sampling line. The capacitor units are connected between the first and second sampling lines, and the resistor units are connected between the first and second sampling lines. n is an integer greater than 1. The device includes a voltage acquisition unit 910, a current determination unit 920, and a disconnection event detection unit 930.

[0099] The voltage acquisition unit 910 is used to acquire the first voltage corresponding to the target current loop among n current loops when the main circuit of the power battery is turned on. The target current loop refers to the current loop that is marked as valid.

[0100] The current determination unit 920 is used to determine the current flowing through the shunt module based on the first voltage corresponding to the target current loop.

[0101] The disconnection event detection unit 930 is used to detect whether a disconnection event has occurred in the target current loop based on the current flowing through the shunt module. The disconnection event refers to the disconnection of the first sampling line included in the target current loop; and / or, the disconnection of the second sampling line included in the target current loop.

[0102] In some embodiments, the disconnection event detection unit 930 is configured to: when the target current loop includes a first current loop and a second current loop, acquire a first difference between a first current and a second current, wherein the first current refers to the current flowing through the shunt module determined based on a first voltage corresponding to the first current loop, and the second current refers to the current flowing through the shunt module determined based on the first voltage corresponding to the second current loop; determine that a disconnection event has occurred in the first current loop or the second current loop if the first difference is greater than a first error threshold; determine that no disconnection event has occurred in the target current loop if the first difference is less than or equal to the first error threshold and the first current is greater than a preset current, or if the first difference is less than or equal to the first error threshold and the second current is greater than the preset current.

[0103] In some embodiments, the disconnection event detection unit 930 is configured to: determine that a disconnection event has occurred in the first current loop when the first difference is greater than the first error threshold and the first current is less than the second current; and determine that a disconnection event has occurred in the second current loop when the first difference is greater than the first error threshold and the first current is greater than the second current.

[0104] In some embodiments, the disconnection event detection unit 930 is configured to: acquire the operating current of the main circuit of the power battery under specified operating conditions when the power battery is under specified operating conditions; acquire the second difference between the current flowing through the shunt module and the operating current of the main circuit of the power battery under specified operating conditions; determine that a disconnection event has occurred in the target current circuit if the second difference is greater than a second error threshold; and determine that no disconnection event has occurred in the target current circuit if the second difference is less than or equal to the second error threshold.

[0105] In some embodiments, the device further includes a signal transmitting unit and a marking unit (not shown in the figure). The signal transmitting unit is used to send a disconnection detection signal to the shunt module when the main circuit of the power battery is disconnected. The voltage acquisition unit 910 is further used to acquire the second voltage corresponding to each of the n current loops under the disconnection detection signal. The disconnection event detection unit 930 is further used to detect whether a disconnection event has occurred in the current loop based on the second voltage corresponding to the current loop. The marking unit is used to mark the current loops that have not experienced a disconnection event as valid.

[0106] In some embodiments, the disconnection event detection unit 930 is configured to: determine that no disconnection event has occurred in the current loop when the difference between the second voltage corresponding to the current loop and the first specified voltage is less than or equal to a third error threshold; and determine that a disconnection event has occurred in the current loop when the second voltage corresponding to the current loop is greater than the second specified voltage, wherein the first specified voltage is less than the second specified voltage.

[0107] In some embodiments, the device further includes a fuse control unit (not shown in the figure). The fuse control unit is used to control the fuse module to blow off the main circuit of the power battery when the current flowing through the shunt module is greater than a safe current threshold.

[0108] In summary, the technical solution provided in this application adds a capacitor unit and a resistor unit between the first and second sampling lines of the current loop. On the one hand, since the voltage between the capacitor units does not change instantaneously, the voltage between the first and second sampling lines remains constant for a period of time. On the other hand, the resistor unit can discharge the energy of the capacitor unit, so that when the first or second sampling line is disconnected, the detection voltage obtained by the current sampling module is clamped at around 0V, avoiding the situation where the detection voltage obtained by the current sampling module is too large when the sampling line is disconnected, which may lead to the false triggering of the fuse module. Furthermore, since the current sampling module will not falsely trigger the fuse module when the sampling line is disconnected, the current sampling module can perform real-time disconnection detection on the target current loop marked as valid when the main circuit of the power battery is conducting. It can detect whether the sampling line is disconnected in time, avoiding the situation where the working current of the main circuit of the power battery cannot be monitored due to the untimely detection of the sampling line disconnection, effectively protecting the working safety of the power battery.

[0109] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working process of the above-described device and module can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0110] In the several embodiments provided in this application, the coupling between modules can be electrical, mechanical, or other forms of coupling.

[0111] Furthermore, the functional modules in the various embodiments of this application can be integrated into one processing module, or each module can exist physically separately, or two or more modules can be integrated into one module. The integrated modules described above can be implemented in hardware or as software functional modules.

[0112] like Figure 10 As shown, this application example also provides a chip 1000, which includes a processor 1010 and a memory 1020. The memory 1020 stores computer program instructions.

[0113] The processor 1010 may include one or more processing cores. The processor 1010 connects to various parts of the entire battery management system using various interfaces and lines, and performs various functions and processes data of the battery management system by running or executing instructions, programs, code sets, or instruction sets stored in the memory 1020, and by calling data stored in the memory 1020. Optionally, the processor 1010 may be implemented using at least one hardware form of Digital Signal Processing (DSP), Field-Programmable Gate Array (FPGA), or Programmable Logic Array (PLA). The processor 1010 may integrate one or a combination of several of the following: Central Processing Unit (CPU), Graphics Processing Unit (GPU), and modem. The CPU primarily handles the operating system, user interface, and applications; the GPU is responsible for rendering and drawing the displayed content; and the modem handles wireless communication. It is understood that the modem may also not be integrated into the processor 1010 and may be implemented separately through a communication chip.

[0114] The memory 1020 may include random access memory (RAM) or read-only memory (ROM). The memory 1020 can be used to store instructions, programs, code, code sets, or instruction sets. The memory 1020 may include a program storage area and a data storage area. The program storage area may store instructions for implementing an operating system, instructions for implementing at least one function (such as touch functionality, sound playback functionality, etc.), and instructions for implementing various method examples described below. The data storage area may also store data generated during the use of the electrical device.

[0115] Please see Figure 11 The present application also provides a computer-readable storage medium 1100, which stores computer program instructions 1110 that can be invoked by a processor to execute the methods described in the above embodiments.

[0116] The computer-readable storage medium 1100 may be an electronic memory such as flash memory, EEPROM (Electrically Erasable Programmable Read-Only Memory), EPROM, hard disk, or ROM. Optionally, the computer-readable storage medium 1100 includes a non-transitory computer-readable storage medium. The computer-readable storage medium 1100 has storage space for computer program instructions 1110 that perform any of the method steps described above. These computer program instructions 1110 can be read from or written to one or more computer program products. The computer program instructions 1110 may be compressed in an appropriate form.

[0117] The above are merely preferred examples of this application and are not intended to limit this application in any way. Although this application has disclosed the preferred examples above, they are not intended to limit this application. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent examples without departing from the scope of the technical solution of this application. Any simple modifications, equivalent changes and alterations made to the above examples based on the technical essence of this application without departing from the scope of the technical solution of this application shall still fall within the scope of the technical solution of this application.

Claims

1. A control method for a power battery protection circuit, characterized in that, The power battery protection circuit includes a shunt module, a current sampling module, n capacitor units, and n resistor units; the shunt module is connected to the main circuit of the power battery; n current loops are formed between the shunt module and the current sampling module, each current loop including a first sampling line and a second sampling line, the first sampling line being connected between the positive terminal of the current sampling module and one side of the shunt module, and the second sampling line being connected between the negative terminal of the current sampling module and the other side of the shunt module; the capacitor units are connected between the first sampling line and the second sampling line, and the resistor units are connected between the first sampling line and the second sampling line, where n is an integer greater than 1; the method includes: When the main circuit of the power battery is turned on, the first voltage corresponding to the target current loop among the n current loops is obtained, where the target current loop refers to the current loop marked as being in an effective state. Based on the first voltage corresponding to the target current loop, the current flowing through the shunt module is determined; Based on the current flowing through the shunt module, it is detected whether a disconnection event has occurred in the target current loop. The disconnection event refers to the disconnection of the first sampling line included in the target current loop; and / or, the disconnection of the second sampling line included in the target current loop.

2. The method according to claim 1, characterized in that, The step of detecting whether a disconnection event has occurred in the target current loop based on the current flowing through the shunt module includes: When the target current loop includes a first current loop and a second current loop, a first difference between the first current and the second current is obtained. The first current refers to the current flowing through the shunt module determined based on the first voltage corresponding to the first current loop, and the second current refers to the current flowing through the shunt module determined based on the first voltage corresponding to the second current loop. If the first difference is greater than the first error threshold, it is determined that the first current loop has experienced the open circuit event, or the second current loop has experienced the open circuit event. If the first difference is less than or equal to the first error threshold and the first current is greater than the preset current, or if the first difference is less than or equal to the first error threshold and the second current is greater than the preset current, it is determined that the target current loop has not experienced the disconnection event.

3. The method according to claim 2, characterized in that, The step of determining that the first current loop has experienced the open circuit event, or the second current loop has experienced the open circuit event, when the first difference is greater than the first error threshold, includes: If the first difference is greater than the first error threshold and the first current is less than the second current, it is determined that the first current loop has experienced the open circuit event. If the first difference is greater than the first error threshold and the first current is greater than the second current, it is determined that the second current loop has experienced the open circuit event.

4. The method according to claim 1, characterized in that, The step of detecting whether a disconnection event has occurred in the target current loop based on the current flowing through the shunt module includes: Under specified operating conditions, the operating current of the main circuit of the power battery under specified operating conditions is obtained. Obtain the second difference between the current flowing through the shunt module and the operating current of the main circuit of the power battery under the specified operating conditions; If the second difference is greater than the second error threshold, it is determined that the target current loop has experienced the open circuit event. If the second difference is less than or equal to the second error threshold, it is determined that the target current loop has not experienced the open circuit event.

5. The method according to any one of claims 1 to 4, characterized in that, Before obtaining the first voltage corresponding to the target current loop among the n current loops, the method further includes: When the main circuit of the power battery is disconnected, a disconnection detection signal is sent to the shunt module; The sampling module obtains the second voltage corresponding to each of the n current loops under the open circuit detection signal. Based on the second voltage corresponding to the current loop, detect whether the open circuit event has occurred in the current loop; The current loop in which the disconnection event did not occur is marked as the valid state.

6. The method according to claim 5, characterized in that, The step of detecting whether the open circuit event has occurred in the current loop based on the second voltage corresponding to the current loop includes: If the difference between the second voltage corresponding to the current loop and the first specified voltage is less than or equal to the third error threshold, it is determined that no open circuit event has occurred in the current loop. If the second voltage corresponding to the current loop is greater than the second specified voltage, it is determined that the current loop has experienced a disconnection event, where the first specified voltage is less than the second specified voltage.

7. The method according to any one of claims 1 to 4, characterized in that, The power battery protection circuit also includes a fuse module, which is connected to the main circuit of the power battery and connected to the current sampling module; After determining the current flowing through the shunt module based on the first voltage corresponding to the target current loop, the method further includes: If the current flowing through the shunt module exceeds the safe current threshold, the fuse module is controlled to blow off the main circuit of the power battery.

8. A control device for a power battery protection circuit, characterized in that, The power battery protection circuit includes a shunt module, a current sampling module, n capacitor units, and n resistor units; the shunt module is connected to the main circuit of the power battery; n current loops are formed between the shunt module and the current sampling module, each current loop including a first sampling line and a second sampling line, the first sampling line being connected to the positive terminal of the current sampling module and one side of the shunt module, and the second sampling line being connected to the negative terminal of the current sampling module and the other side of the shunt module; the capacitor units are connected between the first sampling line and the second sampling line, and the resistor units are connected between the first sampling line and the second sampling line, where n is an integer greater than 1; the device includes: A voltage acquisition unit is used to acquire the first voltage corresponding to a target current loop among n current loops when the main circuit of the power battery is turned on. The target current loop refers to the current loop that is marked as being in an active state. A current determination unit is used to determine the current flowing through the shunt module based on the first voltage corresponding to the target current loop; A disconnection event detection unit is used to detect whether a disconnection event has occurred in the target current loop based on the current flowing through the shunt module. The disconnection event refers to the disconnection of the first sampling line included in the target current loop; and / or, the disconnection of the second sampling line included in the target current loop.

9. A chip, characterized in that, The chip includes: processor; Memory; One or more applications, wherein the one or more said applications are stored in the memory and configured to be executed by one or more said processors, the one or more said applications being configured to perform the method as described in any one of claims 1 to 7.

10. A vehicle, characterized in that, The vehicles include: The main circuit of the power battery, the power battery protection circuit, and the chip as described in claim 9; The power battery protection circuit includes a shunt module, a current sampling module, n capacitor units, and n resistor units. The shunt module is connected to the main circuit of the power battery. n current loops are formed between the shunt module and the current sampling module. Each current loop includes a first sampling line and a second sampling line. The first sampling line is connected between the positive terminal of the current sampling module and one side of the shunt module, and the second sampling line is connected between the negative terminal of the current sampling module and the other side of the shunt module. The capacitor units are connected between the first sampling line and the second sampling line, and the resistor units are connected between the first sampling line and the second sampling line. n is an integer greater than 1.

11. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores program code that is invoked by a processor to execute the method as described in any one of claims 1 to 7.

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