Battery management system, battery pack and electric device

Abstract

The utility model discloses a battery management system, a battery pack and an electric device. The battery management system comprises an anti-reverse circuit, a first resistor, a second resistor and a control circuit, the anti-reverse circuit is coupled between the first voltage source and the first end of the first resistor, and the anti-reverse circuit is used for transmitting the voltage of the first voltage source to the first end of the first resistor; the second end of the first resistor is coupled with the first driving end of the fuse, and the second resistor is coupled between the second driving end of the fuse and the grounding end; the control circuit is coupled with the first driving end and the second driving end, and the control circuit is used for detecting whether the fuse has a fault or not according to the voltage of the first driving end and the voltage of the second driving end. The battery management system provided by the utility model is relatively simple in structure, can detect whether the fuse has a fault or not under the conditions of simplifying the system structure and reducing the cost, does not need to collect current in the detection process, and is relatively simple in detection flow.

Description

Technical Field

[0001] This application relates to the field of battery management technology, and in particular to a battery management system, battery pack and power supply device. Background Technology

[0002] With the increasing popularity of electric vehicles, the high-voltage safety of electric vehicles is receiving more and more attention. Among them, fuses, as an indispensable component in the vehicle circuit, play a key role in circuit protection. Therefore, the reliability of their operation is directly related to the safety of the entire vehicle.

[0003] If a fuse blows, it cannot detonate properly in the event of a vehicle collision or a short circuit in the high-voltage circuit, posing a safety risk. Therefore, researching the fault detection function of fuses is particularly important. Utility Model Content

[0004] This application provides a battery management system, a battery pack, and an electrical device capable of detecting whether a fuse is faulty.

[0005] In a first aspect, this application provides a battery management system, including an anti-reverse circuit, a first resistor, a second resistor, and a control circuit; the anti-reverse circuit is coupled between a first voltage source and a first terminal of the first resistor, and is used to transmit the voltage of the first voltage source to the first terminal of the first resistor; the second terminal of the first resistor is coupled to a first driving terminal of a fuse, and the second resistor is coupled between a second driving terminal of the fuse and a ground terminal; the control circuit is coupled to the first driving terminal and the second driving terminal, and is used to detect whether the fuse is faulty based on the voltage of the first driving terminal and the second driving terminal.

[0006] The battery management system provided in the embodiments of this application has a relatively simple structure by setting up an anti-reverse circuit, a first resistor, a second resistor and a control circuit. It can detect whether the fuse is faulty while simplifying the system structure and reducing costs. Moreover, there is no need to collect current during the detection process, and the detection process is relatively simple.

[0007] In one possible implementation of the first aspect, the anti-reverse circuit includes at least a diode, with the anode of the diode coupled to a first voltage source and the cathode of the diode coupled to a first terminal of a first resistor. This embodiment utilizes the unidirectional conduction characteristic of the diode to achieve both connection between the first voltage source and the first driving terminal, and to prevent reverse charging of the first voltage source in the event of a short-circuit fault in the fuse.

[0008] In one possible implementation of the first aspect, the anti-reverse circuit includes a switching transistor, the first terminal of which is coupled to a first voltage source, the second terminal of which is coupled to a first terminal of a first resistor, and the gate of which is coupled to a control circuit. In this embodiment, if it is determined that there is no short-power supply fault in the fuse, the switching transistor is controlled to conduct, thereby connecting the first voltage source to the first driving terminal; if it is determined that there is a short-power supply fault in the fuse, the switching transistor is controlled to cut off, preventing reverse charging of the first voltage source.

[0009] In one possible implementation of the first aspect, the battery management system further includes an amplification circuit coupled to a first driving terminal, a second driving terminal, and a control circuit. The amplification circuit is used to acquire the voltage drop between the first driving terminal and the second driving terminal, amplify the voltage drop, and transmit it to the control circuit. This embodiment utilizes the amplification circuit to amplify the voltage drop between the first driving terminal and the second driving terminal by a set factor, i.e., amplify the voltage across the fuse, thereby improving the detection accuracy of the fuse's resistance value.

[0010] In one possible implementation of the first aspect, the control circuit is configured to: determine that a short-power supply fault exists in the fuse when at least one of the voltage at the first drive terminal and the voltage at the second drive terminal is equal to voltage U, where U represents the voltage value of the power supply shorted by the drive terminal of the fuse. This solution achieves the diagnosis of whether a short-power supply fault exists in the fuse.

[0011] In one possible implementation of the first aspect, when the first drive terminal and the first voltage source are connected, the control circuit is configured to determine that a short-to-ground fault exists in the fuse if at least one of the voltage at the first drive terminal and the voltage at the second drive terminal is equal to the voltage at the ground terminal. This solution achieves the diagnosis of whether a short-to-ground fault exists in the fuse.

[0012] In one possible implementation of the first aspect, when the first drive terminal and the first voltage source are connected, the control circuit is configured to: determine that the fuse has an open circuit fault when the voltage at the second drive terminal is less than the voltage at the first drive terminal and the voltage at the second drive terminal is less than the voltage drop across the second resistor.

[0013] In one possible implementation of the first aspect, when the first drive terminal and the first voltage source are connected, the control circuit is configured to: determine that the fuse has an open-circuit fault when the voltage at the second drive terminal is not equal to the ground terminal voltage and the output voltage of the amplifier circuit is greater than the voltage of the first voltage source. This solution achieves the diagnosis of whether the fuse has an open-circuit fault.

[0014] In one possible implementation of the first aspect, when the fuse is not faulty, the control circuit is further configured to: determine the resistance value of the fuse based on the equality of the first resistor and the current on the fuse. This solution achieves accurate determination of the fuse's resistance value without collecting current values, based on the equality of the first resistor and the current on the fuse in the same circuit.

[0015] In one possible implementation of the first aspect, the resistance value of the second resistor is greater than the resistance value of the first resistor. When the fuse is not faulty, the control circuit is used to: enable the low-side drive circuit coupled to the second drive terminal; and determine the resistance value of the fuse based on the voltage value of the first voltage source, the voltage divider value of the anti-reverse circuit, the voltage value of the first drive terminal, and the resistance value of the first resistor. This solution achieves accurate determination of the fuse's resistance value, thereby determining whether the fuse's resistance value is abnormal.

[0016] In one possible implementation of the first aspect, the resistance value of the second resistor is less than the resistance value of the first resistor. When the fuse is not faulty, the control circuit is further configured to: control the low-side drive circuit coupled to the second drive terminal to be in an enabled state; and determine the resistance value of the fuse based on the voltage value of the first voltage source, the voltage divider value of the anti-reverse circuit, the voltage value of the first drive terminal, and the resistance value of the first resistor. This solution achieves accurate determination of the fuse's resistance value, thereby determining whether the fuse's resistance value is abnormal.

[0017] Based on the same technical concept, in a second aspect, embodiments of this application provide a battery pack including a battery management system as described in any embodiment of the first aspect.

[0018] Based on the same technical concept, in a third aspect, embodiments of this application provide an electrical device including a battery pack as described in the second aspect embodiment.

[0019] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0020] The features, advantages, and technical effects of exemplary embodiments of this application will now be described with reference to the accompanying drawings.

[0021] Figure 1 This is a schematic diagram of the structure of a battery management system according to an embodiment of this application;

[0022] Figure 2 This is a schematic diagram of another battery management system according to an embodiment of this application;

[0023] Figure 3 This is a schematic diagram of the structure of another battery management system according to an embodiment of this application;

[0024] Figure 4 This is a schematic diagram of the structure of another battery management system according to an embodiment of this application;

[0025] Figure 5 This is a schematic diagram of the structure of another battery management system according to an embodiment of this application;

[0026] Figure 6 This is a schematic diagram of the structure of another battery management system according to an embodiment of this application;

[0027] Figure 7 This is a schematic diagram of the structure of another battery management system according to an embodiment of this application;

[0028] Figure 8 This is a schematic diagram of the structure of another battery management system according to an embodiment of this application;

[0029] Figure 9 This is a schematic diagram of the structure of another battery management system according to an embodiment of this application;

[0030] Figure 10 This is a schematic diagram of a battery pack provided in an embodiment of this application;

[0031] Figure 11 This is a schematic diagram of the structure of an electrical device provided in an embodiment of this application. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, 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 some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0033] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used in the description of this application is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms "comprising" and "having," and any variations thereof, in the description, claims, and accompanying drawings of this application are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the description, claims, or accompanying drawings of this application are used to distinguish different objects, not to describe a specific order or hierarchy.

[0034] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," "coupling," and "attachment" should be interpreted broadly. For example, coupling can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0035] In battery systems, faults such as overcurrent, short circuits, and thermal runaway can all lead to battery fires or even explosions. Battery systems typically use fuses (PyroFuse) to quickly cut off the current path and prevent these dangers from occurring.

[0036] In related technologies, airbag ignition driver integrated circuits are used to drive fuses. These chips typically integrate functions such as fuse detonation, driver line resistance detection, and chip function diagnosis. They communicate with the control circuits through communication methods such as Serial Peripheral Interface (SPI) or Local Interconnect Network (LIN). These chips are expensive and their software implementation is complex.

[0037] To address the aforementioned technical problems, embodiments of this application provide a battery management system, a battery pack, and an electrical device. The battery management system includes an anti-reverse circuit, a first resistor, a second resistor, and a control circuit. The anti-reverse circuit is coupled between a first voltage source and a first terminal of the first resistor, and is used to transmit the voltage from the first voltage source to the first terminal of the first resistor. The second terminal of the first resistor is coupled to a first driving terminal of a fuse, and the second resistor is coupled between the second driving terminal of the fuse and a ground terminal. The control circuit is coupled to both the first and second driving terminals, and is used to detect whether the fuse is faulty based on the voltages at the first and second driving terminals. The battery management system provided by this application, with its anti-reverse circuit, first resistor, second resistor, and control circuit, has a relatively simple structure. It can detect whether a fuse is faulty while simplifying the system structure and reducing costs. Furthermore, the detection process does not require current sampling, making the detection procedure relatively simple.

[0038] The battery management system 100 provided in the embodiments of this application will be described below.

[0039] In one embodiment, such as Figure 1 or Figure 2As shown, the battery management system 100 includes an anti-reverse circuit 1, a first resistor 2, a second resistor 3, and a control circuit 4. The anti-reverse circuit 1 is coupled between a first voltage source VCC1 and a first terminal of the first resistor 2, and is used to transmit the voltage of the first voltage source VCC1 to the first terminal of the first resistor 2. The second terminal of the first resistor 2 is coupled to the first driving terminal 51 of the fuse 5, and the second resistor 3 is coupled between the second driving terminal 52 of the fuse 5 and the ground terminal GND. The control circuit 4 is coupled to the first driving terminal 51 and the second driving terminal 52, and is used to detect whether the fuse 5 is faulty based on the voltage of the first driving terminal 51 and the second driving terminal 52.

[0040] In this embodiment, the driving terminals of the fuse 5 include a first driving terminal 51 and a second driving terminal 52, and the resistance between the first driving terminal 51 and the second driving terminal 52 is denoted as the equivalent resistance R0. Here, the equivalent resistance R0 is the internal resistance value of the fuse to be calculated. In the actual product form, it does not mean that there is a resistor coupled between the two driving terminals of the fuse.

[0041] The first voltage source VCC1 includes a constant voltage source, which can be configured according to the diagnostic current and diagnostic accuracy requirements of the fuse. As an example, the first voltage source VCC1 may include a 5V constant voltage source with a voltage accuracy of ±0.1% and a maximum output current of 100mA.

[0042] The reverse protection circuit 1 is used to transfer the voltage of the first voltage source VCC1 to the first terminal of the first resistor 2, thereby providing voltage to the first drive terminal 51 and the second drive terminal 52. In the event of a short-power supply fault on the fuse 5 side, the reverse protection circuit 1 is also used to prevent the fault from affecting the first voltage source VCC1. The reverse protection circuit 1 may include a diode and / or a switching transistor, which may include a transistor or a PMOS transistor.

[0043] The first resistor 2 acts as a current-limiting resistor to control the current flowing through the fuse 5.

[0044] The second resistor 3 can be used as a current-limiting resistor to control the current flowing through the fuse 5, or as a pull-down resistor to avoid unnecessary floating voltage.

[0045] As an example, such as Figure 1As shown, the battery management system 100 also includes a drive circuit 6 and a second voltage source VCC2. The second voltage source VCC2 is coupled to the drive circuit 6. The input terminal of the drive circuit 6 is coupled to the control circuit 4, and the output terminal is coupled to the first drive terminal 51 and the second drive terminal 52, respectively. The second voltage source VCC2 is a drive voltage source, providing drive voltage to the first drive terminal 51 and the second drive terminal 52 of the fuse 5 through the drive circuit 6. This generates a certain current between the first drive terminal 51 and the second drive terminal 52. If the generated current exceeds a specified value, it can trigger a burst impact to cut off the circuit and achieve the protection function. As an example, the second voltage source VCC2 may include a lead-acid battery or a power source converted from a Buck circuit.

[0046] like Figure 2 As shown, the driving circuit 6 includes a high-side circuit 61 and a low-side circuit 62. The high-side circuit 61 is coupled between the control circuit 4 and the first driving terminal 51, and is also coupled to the second voltage source VCC2. The low-side circuit 62 is coupled between the control circuit 4 and the second driving terminal 52, and is also coupled to the ground terminal GND.

[0047] The control circuit 4 is used to diagnose faults in the fuse 5 based on the voltages at the first drive terminal 51 and the second drive terminal 52. The fault types of the fuse 5 include at least one of the following: short power supply fault, short ground fault, open circuit fault, and excessive resistance fault.

[0048] A short-circuit fault refers to a power supply being abnormally short-circuited. For example, ... Figure 2 As shown, when both the high-side circuit 61 and the low-side circuit 62 are in an disabled state, theoretically the second voltage source VCC2 will not provide voltage to the driving terminal of the fuse 5. If the control circuit 4 detects that at least one of the voltage of the first driving terminal 51 and the voltage of the second driving terminal 52 is equal to the voltage value of the second voltage source VCC2, it indicates that the second voltage source VCC2 is unexpectedly connected to the driving terminal of the fuse 5, and it is determined that the fuse 5 has a short power supply fault.

[0049] A short-to-ground fault refers to an unexpected connection between a node in the circuit containing the fuse and the ground terminal. For example, ... Figure 2 As shown, when both the high-side circuit 61 and the low-side circuit 62 are in an disabled state, the first driving terminal 51 and the first voltage source VCC1 are connected. Due to the presence of the second resistor 3, theoretically, the voltage of the first driving terminal 51 and the voltage of the second driving terminal 52 should be greater than the voltage of the ground terminal GND. If the control circuit 4 detects that at least one of the voltages of the first driving terminal 51 and the second driving terminal 52 is equal to the voltage of the ground terminal GND (i.e., 0V), it indicates that a node in the circuit between the first driving terminal 51 and the second driving terminal 52 is unexpectedly connected to the ground terminal GND, and it is determined that the fuse 5 has a short-to-ground fault.

[0050] An open-circuit fault refers to the unexpected disconnection of the circuit between the first drive terminal 51 and the second drive terminal 52 of fuse 5. For example, as Figure 2 As shown, when both the high-side circuit 61 and the low-side circuit 62 are in an disabled state, the first driving terminal 51 is connected to the first voltage source VCC1. Theoretically, the voltage of the second driving terminal 52 is equal to the voltage division of the second resistor 3. If the control circuit 4 detects that the voltage of the second driving terminal 52 is less than the voltage of the first driving terminal 51, and the voltage of the second driving terminal 52 is less than the voltage division of the second resistor 3, then it is determined that the fuse 5 has an open circuit fault.

[0051] The control circuit 4 is also used to calculate the current value passing through the first resistor 2 based on the voltages of the first driving terminal 51 and the second driving terminal 52, i.e., the voltages across the fuse 5, combined with the voltage division and resistance value of the first resistor 2. If the current value passing through the first resistor 2 is equal to the current value passing through the fuse 5, then the resistance value of the fuse 5 is determined. If the resistance value of the fuse 5 is too high, then the fuse 5 is determined to be malfunctioning.

[0052] The battery management system 100 provided in this application embodiment includes an anti-reverse circuit 1, a first resistor 2, a second resistor 3, and a control circuit 4. The anti-reverse circuit 1 is coupled between a first voltage source VCC1 and a first terminal of the first resistor 2, and is used to transmit the voltage of the first voltage source VCC1 to the first terminal of the first resistor 2. The second terminal of the first resistor 2 is coupled to the first driving terminal 51 of the fuse 5, and the second resistor 3 is coupled between the second driving terminal 52 of the fuse 5 and the ground terminal GND. The control circuit 4 is coupled to the first driving terminal 51 and the second driving terminal 52, and is used to detect whether the fuse 5 is faulty based on the voltage of the first driving terminal 51 and the second driving terminal 52. Based on this, the battery management system 100 is equipped with an anti-reverse circuit 1, a first resistor 2, a second resistor 3, and a control circuit 4. The structure is relatively simple, and it can realize the detection of whether the fuse 5 is faulty while simplifying the system structure and reducing costs. Moreover, there is no need to collect current during the detection process, and the detection process is relatively simple.

[0053] In one embodiment, such as Figure 3 As shown, the anti-reverse circuit 1 includes at least a diode 11. The positive terminal of the diode 11 is coupled to the first voltage source VCC1, and the negative terminal of the diode 11 is coupled to the first end of the first resistor 2.

[0054] In this embodiment, the anti-reverse circuit 1 includes a diode 11. The diode 11 is used to connect the first voltage source VCC1 with the first driving terminal 51 by utilizing its unidirectional conduction characteristic. It can also prevent the first voltage source VCC1 from being reverse-charged when the fuse 5 experiences a short power supply fault.

[0055] In one embodiment, such as Figure 4 As shown, the anti-reverse circuit 1 includes a switching transistor 12. The first terminal of the switching transistor 12 is coupled to the first voltage source VCC1, the second terminal of the switching transistor 12 is coupled to the first end of the first resistor 2, and the gate of the switching transistor 12 is coupled to the control circuit 4.

[0056] As an example, switch 12 may include a PMOS transistor or a bipolar transistor.

[0057] In this embodiment, the control circuit 4 is also used to control the on and off states of the switching transistor 12. When it is determined that there is no short power supply fault in the fuse 5, the control circuit 4 controls the switching transistor 12 to be turned on, and the voltage of the first voltage source VCC1 is transmitted to the first terminal of the first resistor 2 through the switching transistor 12; when it is determined that there is a short power supply fault in the fuse 5, the control circuit 4 controls the switching transistor 12 to be turned off to prevent reverse charging of the first voltage source VCC1.

[0058] In one embodiment, such as Figure 5 As shown, the anti-reverse circuit 1 includes a diode 11 and a switch 12 connected in parallel; the positive terminal of the diode 11 is coupled to the first voltage source VCC1, and the negative terminal of the diode 11 is coupled to the first end of the first resistor 2; the first terminal of the switch 12 is coupled to the first voltage source VCC1, the second terminal of the switch 12 is coupled to the first end of the first resistor 2, and the gate of the switch 12 is coupled to the control circuit 4.

[0059] In this embodiment, when it is uncertain whether the fuse 5 has a short power supply fault, the initial state of the switch tube 12 is set to the off state. The voltage of the first voltage source VCC1 can be transmitted to the first end of the first resistor 2 through the diode 11. The diode 11 is used to prevent the first voltage source VCC1 from being reverse charged. According to the logic that the anti-reverse circuit 1 only includes the diode 11, it is determined whether the fuse has a short power supply fault, a short ground fault, or an open circuit fault.

[0060] If it is determined that there is no short power supply fault in fuse 5, the control circuit can control the switching transistor 12 to conduct. Since the impedance value of the switching transistor 12 is less than the impedance value of the diode 11, the voltage of the first voltage source VCC1 is transmitted to the first end of the first resistor 2 through the switching transistor 12. The current no longer passes through the diode. According to the logic of the anti-reverse circuit 1 which only includes the switching transistor 12, it can be used to determine whether there is a short ground fault or an open circuit fault in the fuse.

[0061] In one embodiment, such as Figure 6 As shown, the battery management system 100 also includes an amplifier circuit 7, which is coupled to the first driving terminal 51, the second driving terminal 52 and the control circuit 4. The amplifier circuit 7 is used to collect the voltage drop between the first driving terminal 51 and the second driving terminal 52, and amplify the voltage drop before transmitting it to the control circuit 4.

[0062] The amplifier circuit 7 only needs to amplify the voltage; this application does not limit the specific structure of the amplifier circuit 7.

[0063] In this embodiment, the voltage drop between the first driving terminal 51 and the second driving terminal 52 refers to the voltage difference between the voltage of the first driving terminal 51 and the voltage of the second driving terminal 52, which is equivalent to the voltage applied across the equivalent resistance R0 of the fuse 5.

[0064] With this configuration, the voltage drop between the first driving terminal 51 and the second driving terminal 52 is amplified by a set factor N (N is greater than 1) using the amplifier circuit 7, which amplifies the voltage across the fuse 5 and improves the detection accuracy of the fuse 5's resistance value.

[0065] In one embodiment, the control circuit is configured to determine that a short-power supply fault exists in the fuse when at least one of the voltage at the first drive terminal and the voltage at the second drive terminal is equal to voltage U, where U represents the voltage value of the power supply shorted by the drive terminal of the fuse.

[0066] Combination Figure 7-9 In any of the diagrams, when both the high-side circuit 61 and the low-side circuit 62 are disabled (i.e., HSD_EN and LSD_EN are low), the switch in the high-side circuit 61 is open, and the switch in the low-side circuit 62 is also open. In this case, the second voltage source VCC2 does not provide a driving voltage. If at least one of the voltage at the first driving terminal 51 and the voltage at the second driving terminal 52 equals the voltage value U (e.g., the voltage value of the second voltage source VCC2), it indicates a short circuit between the second voltage source VCC2 and the driving terminal of the fuse 5, thus confirming a short-circuit fault in the fuse 5.

[0067] In one embodiment, when the first drive terminal and the first voltage source are connected, the control circuit is configured to determine that a short-to-ground fault exists in the fuse if at least one of the voltage at the first drive terminal and the voltage at the second drive terminal is equal to the voltage at the ground terminal.

[0068] Combination Figure 7-9In any of the diagrams, when both the high-side circuit 61 and the low-side circuit 62 are disabled (i.e., HSD_EN and LSD_EN are low), the switch in the high-side circuit 61 is open, and the switch in the low-side circuit 62 is also open. In this case, the second voltage source VCC2 does not provide a driving voltage. When the first driving terminal 51 and the first voltage source VCC1 are connected, the first voltage source VCC1 provides voltage to the first driving terminal 51. Due to the presence of the second resistor 3, theoretically, both the voltage at the first driving terminal 51 and the voltage at the second driving terminal 52 should be greater than the voltage at the ground terminal GND (e.g., 0V). If at least one of the voltages at the first driving terminal 51 and the second driving terminal 52 is equal to the voltage at the ground terminal GND, it indicates that the circuit between the first driving terminal 51 and the second driving terminal 52 is unexpectedly connected to the ground terminal GND, thus confirming a short-to-ground fault in fuse 5.

[0069] In one embodiment, when the first drive terminal and the first voltage source are connected, the control circuit is configured to: determine that the fuse has an open circuit fault when the voltage at the second drive terminal is less than the voltage at the first drive terminal and the voltage at the second drive terminal is less than the voltage drop across the second resistor.

[0070] Combination Figure 7 or Figure 8 When both the high-side circuit 61 and the low-side circuit 62 are disabled (HSD_EN and LSD_EN are both low), the switch in the high-side circuit 61 is open, and the switch in the low-side circuit 62 is also open. In this case, the second voltage source VCC2 does not provide a driving voltage. When the first driving terminal 51 and the first voltage source VCC1 are connected, the first voltage source VCC1 provides voltage to the first driving terminal 51. Theoretically, the voltage at the second driving terminal 52 is equal to the voltage division of the second resistor 3. If the voltage at the second driving terminal 52 is less than the voltage at the first driving terminal 51, and also less than the voltage division of the second resistor 3, it indicates that the circuit between the first driving terminal 51 and the second driving terminal 52 has been accidentally disconnected, thus confirming an open-circuit fault in fuse 5.

[0071] In one embodiment, when the first driving terminal and the first voltage source are connected, the control circuit is used to determine that the fuse has an open circuit fault when the voltage at the second driving terminal is not equal to the ground terminal voltage and the output voltage of the amplifier circuit is greater than the voltage of the first voltage source.

[0072] Combination Figure 9The anti-reverse circuit includes a switching transistor 12 and a second resistor 3 as a current-limiting resistor. When both the high-side circuit 61 and the low-side circuit 62 are disabled (HSD_EN and LSD_EN are low), the switch in the high-side circuit 61 is open, and the switch in the low-side circuit 62 is also open. At this time, the second voltage source VCC2 does not provide a driving voltage. If it is determined that the fuse 5 does not have a short-circuit fault, the control switching transistor 12 is turned on, connecting the first driving terminal 51 to the first voltage source VCC1. If the voltage at the second driving terminal 52 is not equal to the ground terminal GND voltage (e.g., 0V), and the output voltage of the amplifier circuit 7 is greater than the voltage of the first voltage source VCC1, it is determined that the fuse has an open-circuit fault.

[0073] In one embodiment, when there is no fault in the fuse, the control circuit is also used to: determine the resistance value of the fuse based on the fact that the first resistor and the current on the fuse are equal.

[0074] In this embodiment, since the fuse and the first resistor are connected in series, the current flowing through them is equal. After determining the current flowing through the first resistor, the resistance value of the fuse can be determined based on the voltage of the first driving terminal and the voltage of the second driving terminal.

[0075] For example, the current flowing through the first resistor and the fuse can be calculated based on the voltage across the first resistor and the resistance value of the first resistor. Then, the resistance value of the fuse can be calculated based on the voltage across the fuse. In this way, only the voltage value needs to be collected, and the current value does not need to be collected separately, so that the resistance of the fuse can be detected.

[0076] In one embodiment, the resistance value of the second resistor is greater than the resistance value of the first resistor. When there is no fault in the fuse, the control circuit is used to: control the low-side drive circuit coupled to the second drive terminal to be in an enabled state, and determine the resistance value of the fuse based on the voltage value of the first voltage source, the voltage division value of the anti-reverse circuit, the voltage value of the first drive terminal, and the resistance value of the first resistor.

[0077] In this embodiment, the first resistor serves as a current-limiting resistor, and the second resistor serves as a pull-down resistor.

[0078] Combination Figures 7-9 In any case, assuming the fuse does not have the aforementioned short-power supply fault, short-ground fault, or open-circuit fault, the control circuit 4 sends a low-level HSD_EN signal to the high-side circuit 61 and a high-level LSD_EN signal to the low-side circuit 62, enabling the low-side circuit 62 and closing the switch in it. The control circuit then detects the voltage at the first drive terminal 51 and the voltage at the second drive terminal 52. If the voltage at the second drive terminal 52 is found to be 0V, the low-side circuit is confirmed to be enabled. The resistance value of the fuse 5 is then calculated according to formula (1).

[0079]

[0080] in, The resistance value represents the equivalent resistance of fuse 5. This indicates the resistance value of the first resistor, 2. This indicates the voltage value at the first drive terminal 51. This indicates the voltage value of the first voltage source VCC1. This indicates the voltage divider value of the anti-reverse circuit.

[0081] For example, such as Figure 7 As shown, the anti-reverse circuit includes diode 11 and second resistor 3 as a pull-down resistor. When both high-side circuit 61 and low-side circuit 62 are disabled (HSD_EN and LSD_EN are low), the switch in high-side circuit 61 is open, and the switch in low-side circuit 62 is also open. At this time, the second voltage source VCC2 does not provide drive voltage. The specific process of fault diagnosis for fuse 5 by control circuit 4 is as follows:

[0082] (a) If at least one of the voltage of the first driving terminal 51 and the voltage of the second driving terminal 52 is equal to the voltage of the second voltage source VCC2, then it is determined that there is a short power supply fault in the fuse 5.

[0083] (b) If the voltage at the first drive terminal 51 or the voltage at the second drive terminal 52 is equal to 0V, then it is determined that there is a short-to-ground fault in the fuse 5.

[0084] (c) If the voltage at the first driving terminal 51 is less than the voltage at the second driving terminal 52, and the voltage at the second driving terminal 52 is less than the voltage drop across the second resistor 3, then the fuse 5 is determined to have an open circuit fault. The voltage drop across the second resistor 3 is calculated using formula (2):

[0085]

[0086] in, This indicates the voltage drop value of diode 11.

[0087] (d) If the above-mentioned fault exists in fuse 5, the fault is directly set and the diagnostic process ends. If the above-mentioned fault does not exist in fuse 5, the resistance value of fuse 5 is determined. The specific process is as follows: the HSD_EN signal sent by control circuit 4 to high-side circuit 61 is low level, and the LSD_EN signal sent to low-side circuit 62 is high level, enabling low-side circuit 62, so that the switch in low-side circuit 62 is in the closed state, detecting the voltage of the first driving terminal 51 and the voltage of the second driving terminal 52, and when the voltage of the second driving terminal 52 is detected to be equal to 0V, it is determined that low-side circuit 62 has been enabled, and the resistance value of fuse 5 is calculated according to formula (3).

[0088]

[0089] The calculated resistance value of fuse 5 is compared with the preset resistance threshold range. If it exceeds the preset threshold range, the resistance value of fuse 5 is confirmed to be abnormal.

[0090] For example, such as Figure 8 As shown, the anti-reverse circuit includes a switching transistor 12 and a second resistor 3 as a pull-down resistor. When both the high-side circuit 61 and the low-side circuit 62 are disabled (i.e., HSD_EN is low and LSD_EN is low), the switch in the high-side circuit 61 is open, and the switch in the low-side circuit 62 is also open. At this time, the second voltage source VCC2 does not provide drive voltage. The specific process of the control circuit 4 performing fault diagnosis on the fuse 5 is shown below:

[0091] (a) If at least one of the voltage of the first driving terminal 51 and the voltage of the second driving terminal 52 is equal to the voltage of the second voltage source VCC2, then it is determined that there is a short power supply fault in the fuse 5.

[0092] (b) If a short power supply fault exists in fuse 5, the fault is directly set and the diagnostic process ends. If there is no short power supply fault in fuse 5, the control circuit 4 controls the switch tube 12 to conduct, and detects the voltage of the first drive terminal 51 and the voltage of the second drive terminal 52. If the voltage of the first drive terminal 51 or the voltage of the second drive terminal 52 is equal to 0V, it is determined that there is a short ground fault in fuse 5.

[0093] (c) If the voltage at the first driving terminal 51 is less than the voltage at the second driving terminal 52, and the voltage at the second driving terminal 52 is less than the voltage drop across the second resistor 3, then the fuse 5 is determined to have an open circuit fault. The voltage drop across the second resistor 3 is calculated using formula (4):

[0094]

[0095] When the switching transistor 12 is in the on state, its corresponding voltage division value is approximately equal to 0V.

[0096] (d) If there is a short-circuit fault or an open-circuit fault in fuse 5, the fault is directly set and the diagnostic process ends. If there is no short-circuit fault or open-circuit fault in fuse 5, the resistance value of fuse 5 is determined. The specific process is as follows: control circuit 4 sends HSD_EN signal to high-side circuit 61 at a low level and sends LSD_EN signal to low-side circuit 62 at a high level to enable low-side circuit 62, so that the switch in low-side circuit 62 is in the closed state. The voltage of the first driving terminal 51 and the voltage of the second driving terminal 52 are detected. When the voltage of the second driving terminal 52 is detected to be 0V, it is determined that the low-side circuit has been enabled. The resistance value of fuse 5 is calculated according to formula (5).

[0097]

[0098] The calculated resistance value of fuse 5 is compared with the preset resistance threshold range. If it exceeds the preset threshold range, the resistance value of fuse 5 is confirmed to be abnormal.

[0099] For example, such as Figure 9 As shown, the anti-reverse circuit includes a switching transistor 12, a second resistor 3 as a pull-down resistor, and an amplifier circuit 7 with an amplification factor of N, where N is greater than 1. When both the high-side circuit 61 and the low-side circuit 62 are disabled (i.e., HSD_EN and LSD_EN are low), the switch in the high-side circuit 61 is open, and the switch in the low-side circuit 62 is also open. In this case, the second voltage source VCC2 does not provide a driving voltage. The specific process of the control circuit 4 performing fault diagnosis on the fuse 5 is shown below:

[0100] (a) If at least one of the voltage of the first driving terminal 51 and the voltage of the second driving terminal 52 is equal to the voltage of the second voltage source VCC2, then it is determined that there is a short power supply fault in the fuse 5.

[0101] (b) If a short power supply fault exists in fuse 5, the fault is directly set and the diagnostic process ends. If there is no short power supply fault in fuse 5, the control circuit 4 controls the switch tube 12 to conduct, and detects the voltage of the first drive terminal 51 and the voltage of the second drive terminal 52. If the voltage of the first drive terminal 51 or the voltage of the second drive terminal 52 is equal to 0V, it is determined that there is a short ground fault in fuse 5.

[0102] (c) If the voltage of the second driving terminal 52 is not equal to 0V and the output voltage of the amplifier circuit 7 is greater than the voltage of the first voltage source VCC1, it is determined that the fuse 5 has an open circuit fault.

[0103] (d) If fuse 5 has a short-to-ground fault or an open-circuit fault, the fault is directly set and the diagnostic process ends. If fuse 5 does not have a short-to-ground fault or an open-circuit fault, the resistance value of fuse 5 is determined. The specific process is as follows: control circuit 4 sends HSD_EN signal to high-side circuit 61 at a low level and sends LSD_EN signal to low-side circuit 62 at a high level to enable low-side circuit 62, so that the switch in low-side circuit 62 is in the closed state. The voltage of the first driving terminal 51 and the voltage of the second driving terminal 52 are detected. When the voltage of the second driving terminal 52 is detected to be 0V, it is determined that the low-side circuit has been enabled. The resistance value of fuse 5 is calculated according to formula (6). The calculated resistance value of fuse 5 is compared with the preset resistance threshold range. If it exceeds the preset threshold range, the resistance value of fuse 5 is confirmed to be abnormal.

[0104]

[0105] in, This indicates the output voltage of amplifier circuit 7.

[0106] In one embodiment, the resistance value of the second resistor is less than the resistance value of the first resistor. In the absence of a fuse fault, the control circuit is further configured to: control the low-side drive circuit coupled to the second drive terminal to be in an enabled state, and determine the resistance value of the fuse based on the voltage value of the first voltage source, the voltage divider value of the anti-reverse circuit, the voltage value of the first drive terminal, and the resistance value of the first resistor.

[0107] In this embodiment, both the first resistor and the second resistor serve as current-limiting resistors.

[0108] Combination Figure 8 The first resistor 2 and the second resistor 3 are both used as current-limiting resistors. If it is determined that the fuse 5 does not have the aforementioned short-power supply fault, short-ground fault, or open-circuit fault, the control circuit 4 sends a low-level HSD_EN signal to the high-side circuit 61 and a low-level LSD_EN signal to the low-side circuit 62. Both the high-side circuit 61 and the low-side circuit 62 are in an disabled state. The switch in the high-side circuit 61 is in an open state, and the switch in the low-side circuit 62 is in an open state. The voltage of the first driving terminal 51 and the voltage of the second driving terminal 52 are detected. If the voltage of the second driving terminal 52 is less than the voltage of the first driving terminal 51, the resistance value of the fuse 5 is calculated according to formula (7):

[0109]

[0110] In this case, the switching transistor 12 is in the on state, and its corresponding voltage division value is approximately 0V.

[0111] For example, such as Figure 8As shown, the anti-reverse circuit includes a switching transistor 12 and a second resistor 3 as a current-limiting resistor. When both the high-side circuit 61 and the low-side circuit 62 are disabled (i.e., HSD_EN and LSD_EN are low), the switch in the high-side circuit 61 is open, and the switch in the low-side circuit 62 is also open. At this time, the second voltage source VCC2 does not provide a driving voltage. The specific process of the control circuit 4 performing fault diagnosis on the fuse 5 is shown below:

[0112] (a) If at least one of the voltage of the first driving terminal 51 and the voltage of the second driving terminal 52 is equal to the voltage of the second voltage source VCC2, then it is determined that there is a short power supply fault in the fuse 5.

[0113] (b) If a short power supply fault exists in fuse 5, the fault is directly set and the diagnostic process ends. If there is no short power supply fault in fuse 5, the control circuit 4 controls the switch tube 12 to conduct, and detects the voltage of the first drive terminal 51 and the voltage of the second drive terminal 52. If the voltage of the first drive terminal 51 or the voltage of the second drive terminal 52 is equal to 0V, it is determined that there is a short ground fault in fuse 5.

[0114] (c) If the voltage at the first driving terminal 51 is less than the voltage at the second driving terminal 52, and the voltage at the second driving terminal 52 is less than the voltage drop across the second resistor 3, then the fuse 5 is determined to have an open circuit fault. The voltage drop across the second resistor 3 is calculated using formula (4):

[0115]

[0116] When the switching transistor 12 is in the on state, its corresponding voltage division value is approximately equal to 0V.

[0117] (d) If fuse 5 has a short-to-ground fault or an open-circuit fault, the fault is directly set and the diagnostic process ends. If fuse 5 does not have a short-to-ground fault or an open-circuit fault, the resistance value of fuse 5 is determined. The specific process is as follows: detect the voltage of the first driving terminal 51 and the voltage of the second driving terminal 52. If the voltage of the second driving terminal 52 is less than the voltage of the first driving terminal 51, calculate the resistance value of fuse 5 according to formula (7):

[0118]

[0119] The calculated resistance value of fuse 5 is compared with the preset resistance threshold range. If it exceeds the preset threshold range, the resistance value of fuse 5 is confirmed to be abnormal.

[0120] Based on the same technical concept, embodiments of this application also provide a battery pack. For example... Figure 10As shown, the battery pack 1000 provided in this application embodiment includes a battery group 200 and a battery management system 100 as described in any of the above embodiments.

[0121] It is understood that the battery pack has the beneficial effects of the battery management system provided in the embodiments of this application. For details, please refer to the specific descriptions of the battery management system in the above embodiments. This embodiment will not repeat them here.

[0122] Based on the same technical concept, this application also provides an electrical device. For example... Figure 11 As shown, the power supply device 2000 provided in this application embodiment includes a battery pack 1000 as described in any of the above embodiments.

[0123] It is understood that the electrical device has the beneficial effects of the battery pack provided in the embodiments of this application. For details, please refer to the specific description of the battery pack in the above embodiments. This embodiment will not repeat the description here.

[0124] It should be noted that in the above embodiments, the resistor is presented as a single resistor. In other embodiments, the resistor may also be an integrated combination of series, parallel, or mixed resistors. Similarly, in the above embodiments, the capacitor is presented as a single capacitor. In other embodiments, the capacitor may also be an integrated combination of series, parallel, or mixed capacitors. The specific parameters of each device can be set according to actual needs, and this application does not limit this.

[0125] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other.

[0126] Although this application has been described with reference to preferred embodiments, various modifications can be made thereto and components can be replaced with equivalents without departing from the scope of this application. In particular, the technical features mentioned in the various embodiments can be combined in any manner, provided there is no structural conflict. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A battery management system, characterized by, The anti-reverse circuit, the first resistor, the second resistor and the control circuit are included. The anti-reverse circuit is coupled between the first voltage source and the first end of the first resistor, and is configured to transmit the voltage of the first voltage source to the first end of the first resistor. The second end of the first resistor is coupled with the first driving end of the fuse, and the second resistor is coupled between the second driving end and the ground end of the fuse. The control circuit is coupled with the first driving end and the second driving end, and is configured to detect whether the fuse has a fault according to the voltages of the first driving end and the second driving end.

2. The battery management system of claim 1, wherein, The anti-reverse circuit includes at least a diode, the anode of the diode is coupled with the first voltage source, and the cathode of the diode is coupled with the first end of the first resistor.

3. The battery management system of claim 1, wherein, The anti-reverse circuit includes a switch tube, the first pole of the switch tube is coupled with the first voltage source, the second pole of the switch tube is coupled with the first end of the first resistor, and the gate of the switch tube is coupled with the control circuit.

4. The battery management system of claim 1, wherein, The battery management system further includes an amplification circuit, the amplification circuit is coupled with the first driving end, the second driving end and the control circuit, and is configured to collect the voltage drop of the first driving end and the second driving end, and transmit the voltage drop to the control circuit after amplification.

5. The battery management system of claim 1, wherein, The control circuit is configured to determine that the fuse has a short power supply fault in a case where at least one of the voltage of the first driving end and the voltage of the second driving end is equal to a voltage U, U representing the voltage value of the power supply short-circuited by the driving end of the fuse.

6. The battery management system of claim 1, wherein, In a case where the first driving end is in communication with the first voltage source, the control circuit is configured to determine that the fuse has a short ground fault in a case where at least one of the voltage of the first driving end and the voltage of the second driving end is equal to the voltage of the ground end.

7. The battery management system of claim 2 or 3, wherein, In a case where the first driving end is in communication with the first voltage source, the control circuit is configured to determine that the fuse has an open circuit fault in a case where the voltage of the second driving end is less than the voltage of the first driving end, and the voltage of the second driving end is less than the voltage drop of the second resistor.

8. The battery management system of claim 4, wherein, In a case where the first driving end is in communication with the first voltage source, the control circuit is configured to determine that the fuse has an open circuit fault in a case where the voltage of the second driving end is not equal to the voltage of the ground end, and the output voltage of the amplification circuit is greater than the voltage of the first voltage source.

9. The battery management system of claim 1, wherein, In a case where the fuse has no fault, the control circuit is further configured to determine the resistance value of the fuse based on the equality of the current on the first resistor and the fuse.

10. The battery management system of claim 9, wherein, The resistance value of the second resistor is greater than the resistance value of the first resistor, and in a case where the fuse has no fault, the control circuit is configured to control the low-side driving circuit coupled with the second driving end to be in an enabled state, and determine the resistance value of the fuse according to the voltage value of the first voltage source, the voltage drop value of the anti-reverse circuit, the voltage value of the first driving end and the resistance value of the first resistor.

11. The battery management system of claim 9, wherein, The second resistor has a resistance value less than a resistance value of the first resistor, and the control circuit is further configured to, in a case where the fuse has no fault, control the low-side drive circuit coupled to the second drive end to be in a disabled state, and determine the resistance value of the fuse according to a voltage value of the first voltage source, a voltage value of the first drive end, a voltage value of the second drive end, and the resistance value of the first resistor.

12. A battery pack, characterized by A battery management system as claimed in any one of claims 1 to 11.

13. An electrical device, characterized by A battery pack as claimed in claim 12.

Images