Signal circuit of cascaded battery pack, battery system, energy storage system and vehicle

Abstract

The invention relates to the field of electronic circuits, in particular to a signal circuit of a cascade battery pack, a battery system, an energy storage system and a vehicle. The signal circuit comprises an identification circuit, the input end of the identification circuit is connected with the signal input end of the battery pack, the signal input end of the battery pack is suitable for being connected with the signal output end of a superior circuit, and the output end of the identification circuit is connected with the first controller; the output end of the transmission circuit is connected with the signal output end of the battery pack, the signal output end of the battery pack is suitable for being connected with the signal input end of a subordinate circuit, and the control end of the transmission circuit is connected with the first controller; when the fault position is transmitted, the first controller identifies the fault position signal transmitted by the superior circuit through the identification circuit, updates the fault position signal based on the fault detection result of the battery pack, and controls the transmission circuit to output the updated fault position signal and transmit the updated fault position signal to the signal input end of the subordinate circuit. Therefore, the transmission of the fault position can be realized.

Description

Technical Field

[0001] This application relates to the field of electronic circuits, specifically to a signal circuit for a cascaded battery pack, a battery system, an energy storage system, and a vehicle. Background Technology

[0002] Currently, high-voltage battery systems can be implemented using multiple cascaded battery packs. When a single battery pack fails, the fault needs to be transmitted to the battery management unit (BMU) via a hard-wired signal so that the BMU can respond quickly to the emergency. Therefore, a corresponding dry contact signal circuit is required to transmit fault information across the cascaded battery packs.

[0003] In related technologies, dry contact signal circuits of each battery pack are connected in series or in parallel to transmit faults, but neither of these methods can locate the fault location. Summary of the Invention

[0004] In view of the above problems, this application provides a signal circuit, battery system, energy storage system and vehicle for a cascaded battery pack, which can realize the transmission of fault location, thereby realizing the location of fault.

[0005] In a first aspect, this application provides a signal circuit for a cascaded battery pack, comprising: an identification circuit, the input terminal of which is connected to the signal input terminal of the battery pack, the signal input terminal of the battery pack being adapted to connect to the signal output terminal of an upper-level circuit, and the output terminal of the identification circuit being connected to a first controller; wherein the upper-level circuit is a signal circuit or battery management unit of an upper-level battery pack; and a transmission circuit, the output terminal of which is connected to the signal output terminal of the battery pack, the signal output terminal of the battery pack being adapted to connect to the signal input terminal of a lower-level circuit, and the control terminal of the transmission circuit being connected to the first controller; wherein the lower-level circuit is a signal circuit or battery management unit of a lower-level battery pack; when transmitting fault location, the first controller identifies the fault location signal transmitted by the upper-level circuit through the identification circuit, updates the fault location signal based on the fault detection result of the battery pack, and controls the transmission circuit to output the updated fault location signal and transmit it to the signal input terminal of the lower-level circuit.

[0006] In the technical solution of this application embodiment, by setting up an identification circuit and a transmission circuit, and when transmitting the fault location, the first controller identifies the fault location signal transmitted by the upper-level circuit through the identification circuit, updates the fault location signal based on the fault detection result of the battery pack, and controls the transmission circuit to output the updated fault location signal and transmit it to the signal input terminal of the lower-level circuit, thereby realizing the transmission of the fault location and thus realizing the location of the fault location.

[0007] In some embodiments, the fault location signal is a pulse signal, which includes multiple pulse cycles. Each pulse cycle corresponds to a battery pack, and the sequence number of the pulse cycle corresponds to the cascaded position of the battery packs. The level state of each pulse cycle is used to characterize the fault detection result of the corresponding battery pack. Thus, fault location can be transmitted simply and reliably via pulse transmission.

[0008] In some embodiments, the transmission circuit includes a first power supply and a switching circuit. The first power supply is connected to the signal output terminal of the battery pack via the switching circuit. A first controller is connected to the control terminal of the switching circuit and is used to control the switching circuit to turn on or off to output an updated fault location signal. Thus, by controlling the output of the first power supply via the switching circuit, pulse signals can be transmitted, thereby achieving fault location transmission in a simple and reliable manner.

[0009] In some embodiments, the switching circuit includes: a first optocoupler and a first switch. A first terminal of the first optocoupler is connected to a second power supply via the first switch, a second terminal of the first optocoupler is grounded, a third terminal of the first optocoupler is connected to the first power supply, and a fourth terminal of the first optocoupler is connected to the signal output terminal of the battery pack. A first controller is connected to the control terminal of the first switch and is used to control the first switch to be on or off, thereby controlling the switching circuit to be on or off to output an updated fault location signal. This not only controls the output of the first power supply but also provides isolation.

[0010] In some embodiments, the switching circuit includes: a first optocoupler and a second switch. A first terminal of the first optocoupler is connected to a second power supply, a second terminal of the first optocoupler is grounded through the second switch, a third terminal of the first optocoupler is connected to a first power supply, and a fourth terminal of the first optocoupler is connected to the signal output terminal of the battery pack. A first controller is connected to the control terminal of the second switch and is used to control the second switch to be on or off, thereby controlling the switching circuit to be on or off to output an updated fault location signal. This not only controls the output of the first power supply but also provides isolation.

[0011] In some embodiments, the switching circuit includes: a first optocoupler, a first switch, and a second switch. A first terminal of the first optocoupler is connected to the output terminal of the identification circuit. The first terminal of the first optocoupler is also connected to a second power supply via the first switch. A second terminal of the first optocoupler is grounded via the second switch. A third terminal of the first optocoupler is connected to the first power supply, and a fourth terminal of the first optocoupler is connected to the signal output terminal of the battery pack. A first controller is connected to the control terminals of the first and second switches respectively, and is used to control the first and second switches to be on or off, thereby controlling the switching circuit to be on or off to output an updated fault location signal. In this way, not only can the output of the first power supply be controlled, but it also provides isolation. Simultaneously, fault signals from the upper-level circuit can be directly transmitted to the lower-level circuit without the intervention of the first controller.

[0012] In some embodiments, the switching circuit further includes a first resistor connected in series between a first terminal of the first optocoupler and the output terminal of the identification circuit. This provides current-limiting protection.

[0013] In some embodiments, the identification circuit includes: a second optocoupler, the first end of which serves as the input terminal of the identification circuit, the second end of which is grounded, the third end of which is connected to a second power supply, and the fourth end of which serves as the output terminal of the identification circuit. Thus, not only can fault signals and fault location signals from the upstream circuit be identified, but it also provides isolation.

[0014] In some embodiments, the identification circuit further includes a second resistor, one end of which is connected to the first terminal of the second optocoupler, and the other end of which serves as the input terminal of the identification circuit. This provides current-limiting protection.

[0015] In some embodiments, the first controller is further configured to transmit the fault location before transmitting the fault location, and during fault transmission, if the identification circuit identifies a fault in the upper-level circuit and / or the battery pack fault detection result is a fault, control the transmission circuit to output a fault signal and transmit it to the signal input terminal of the lower-level circuit. This enables rapid transmission of the fault signal.

[0016] In some embodiments, before transmitting the fault location, the identification circuit is also used to receive the fault signal from the upper-level circuit and transmit it to the signal input terminal of the lower-level circuit through the transmission circuit for fault transmission. In this way, the fault signal from the upper-level circuit can be directly transmitted to the lower-level circuit without the participation of the first controller.

[0017] Secondly, this application provides a battery system, including: a first battery pack and a second battery pack, both the first and second battery packs including the aforementioned signal circuit, the signal output terminal of the first battery pack being connected to the signal input terminal of the second battery pack; and a battery management unit, the signal output terminal of the battery management unit being connected to the signal input terminal of the first battery pack and the signal input terminal of the battery management unit being connected to the signal output terminal of the second battery pack, for receiving fault signals and fault location signals transmitted by the second battery pack, and performing protection control based on the fault signals and determining the battery pack that has failed based on the fault location signals.

[0018] In some embodiments, the system further includes at least one third battery pack, which is cascaded between the signal output terminal of the first battery pack and the signal input terminal of the second battery pack, and each third battery pack includes the aforementioned signal circuit.

[0019] In some embodiments, the battery management unit includes a third power source connected to the signal output terminal of the battery management unit.

[0020] In some embodiments, the battery management unit includes a second controller and a sampling circuit. The input terminal of the sampling circuit is connected to the signal input terminal of the battery management unit, and the output terminal of the sampling circuit is connected to the second controller. The second controller is used to sample the voltage of the signal input terminal of the battery management unit through the sampling circuit to obtain the fault signal and fault location signal transmitted by the second battery pack.

[0021] Thirdly, this application provides an energy storage system, including the aforementioned signal circuit or battery system.

[0022] Fourthly, this application provides a vehicle including the aforementioned signal circuit or battery system.

[0023] 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

[0024] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiments below. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0025] Figure 1 This is a schematic diagram of the signal circuit of the cascaded battery pack according to the first embodiment of this application.

[0026] Figure 2 This is a schematic diagram of a fault location signal according to an embodiment of this application.

[0027] Figure 3 This is a schematic diagram of the signal circuit of the cascaded battery pack according to the second embodiment of this application.

[0028] Figure 4 This is a schematic diagram of the signal circuit of the cascaded battery pack according to the third embodiment of this application.

[0029] Figure 5 This is a schematic diagram of the signal circuit of the cascaded battery pack according to the fourth embodiment of this application.

[0030] Figure 6 This is a schematic diagram of the signal circuit of the cascaded battery pack according to the fifth embodiment of this application.

[0031] Figure 7 for Figure 4The circuit diagram of the signal circuit of the cascaded battery pack shown is shown.

[0032] Figure 8 for Figure 5 The circuit diagram of the signal circuit of the cascaded battery pack shown is shown.

[0033] Figure 9 for Figure 6 The circuit diagram of the signal circuit of the cascaded battery pack shown is shown.

[0034] Figure 10 This is a schematic diagram of the signal circuit when two battery packs are cascaded according to the first embodiment of this application.

[0035] Figure 11 This is a schematic diagram of the signal circuit when multiple battery packs are cascaded according to the second embodiment of this application.

[0036] Figure 12 This is a schematic diagram of the battery system according to the first embodiment of this application.

[0037] Figure 13 This is a schematic diagram of the battery system according to the second embodiment of this application. Detailed Implementation

[0038] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0039] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein 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 specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0040] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0041] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0042] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0043] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple groups" refers to two or more (including two groups), and "multiple pieces" refers to two or more (including two pieces).

[0044] In the description of the embodiments of this application, the technical terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0045] In the description of the embodiments of this application, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0046] Currently, high-voltage battery systems can be implemented using multiple cascaded battery packs. When a single battery pack fails, the fault needs to be transmitted to the battery management unit (BMU) via a hard-wired signal so that the BMU can respond quickly to the emergency. Therefore, a corresponding dry contact signal circuit is required to transmit fault information across the cascaded battery packs.

[0047] In related technologies, dry contact signal circuits of each battery pack are connected in series or in parallel to transmit faults, but neither of these methods can locate the fault location.

[0048] Based on this, this application provides a signal circuit for a cascaded battery pack. When transmitting the fault location, the first controller identifies the fault location signal transmitted by the upper-level circuit through the identification circuit, updates the fault location signal based on the fault detection result of the battery pack, and controls the transmission circuit to output the updated fault location signal and transmit it to the signal input terminal of the lower-level circuit. In this way, the transmission of the fault location can be realized, thereby realizing the location of the fault.

[0049] The signal circuit of the cascaded battery pack disclosed in this application can be used in battery packs that need to be cascaded, such as in a high-voltage battery system. This system includes multiple cascaded battery packs, each including the aforementioned signal circuit to transmit fault information and fault location. The high-voltage battery system can be applied to energy storage systems or vehicles. The energy storage system may include one or more high-voltage battery systems, and the vehicle includes, but is not limited to, pure electric vehicles or hybrid electric vehicles. Each battery pack may include multiple battery modules, which can be connected in series, parallel, or series-parallel. Each battery module may include multiple individual battery cells, which can also be connected in series, parallel, or series-parallel.

[0050] The signal circuit of the cascaded battery pack of this application will be described below with reference to specific embodiments.

[0051] Figure 1 This is a schematic diagram of the signal circuit of a cascaded battery pack according to an embodiment of this application.

[0052] Reference Figure 1 The signal circuit of the cascaded battery pack includes an identification circuit 110 and a transmission circuit 120. The input terminal of the identification circuit 110 is connected to the signal input terminal IN of the battery pack, which is adapted to connect to the signal output terminal of the upper-level circuit. The output terminal of the identification circuit 110 is connected to the first controller 130. The output terminal of the transmission circuit 120 is connected to the signal output terminal OUT of the battery pack, which is adapted to connect to the signal input terminal of the lower-level circuit. The control terminal of the transmission circuit 120 is connected to the first controller 130. When transmitting fault location information, the first controller 130 identifies the fault location signal transmitted by the upper-level circuit through the identification circuit 110, updates the fault location signal based on the fault detection result of the battery pack, and controls the transmission circuit 120 to output the updated fault location signal and transmit it to the signal input terminal of the lower-level circuit.

[0053] It should be noted that the upper-level circuit can be the signal circuit or battery management unit of the upper-level battery pack, and the lower-level circuit can be the signal circuit or battery management unit of the lower-level battery pack. That is, the signal circuit of the current battery pack may be connected to the signal circuit of the upper-level battery pack cascaded with the current battery pack, or it may be directly connected to the battery management unit. Similarly, the signal circuit of the current battery pack may be connected to the signal circuit of the lower-level battery pack cascaded with the current battery pack, or it may be directly connected to the battery management unit. The first controller 130 can be located inside or outside the signal circuit, or it can reuse the original BMS (Battery Management System) of the battery pack; there are no restrictions here. It should be noted that the original BMS of the battery pack refers to a single battery pack, while the battery management unit refers to multiple cascaded battery packs and is used for comprehensive management of multiple cascaded battery packs.

[0054] For example, during fault location transmission, the upstream circuit (such as the signal circuit of the upstream battery pack connected to the current battery pack) transmits the corresponding fault location signal to the signal input terminal IN of the current battery pack. The first controller 130 identifies the signal at the signal input terminal IN through the identification circuit 110, thereby obtaining the fault location signal transmitted by the upstream circuit. For instance, the identification circuit 110 converts the signal at the signal input terminal IN into a signal that the first controller 130 can sample and outputs it. Then, the first controller 130 samples the signal and determines the fault location signal transmitted by the upstream circuit, such as a high or low level signal, based on the sampled signal.

[0055] Then, the first controller 130 updates the fault location signal based on the fault detection result of the current battery pack. For example, if the fault detection result is a fault, a signal indicating that the current battery pack has a fault can be added to the fault location signal, such as adding a low-level signal at the end of the fault location signal; if the fault detection result is normal, a signal indicating that the current battery pack does not have a fault can be added to the fault location signal, such as adding a high-level signal at the end of the fault location signal.

[0056] Then, the first controller 130 controls the transmission circuit 120 to output the updated fault location signal to the signal output terminal OUT of the current battery pack. This signal is then transmitted through the signal output terminal OUT to the signal input terminal of the next-level circuit (such as the signal circuit of a lower-level battery pack connected to the current battery pack). The signal is then transmitted step-by-step through the next-level circuit, eventually reaching the target device, such as the battery management unit. The battery management unit then determines the location of the faulty battery pack based on the fault location signal. For example, the battery management unit can determine the faulty battery pack based on the position of a low-level signal in the fault location signal, thereby achieving fault location transmission and positioning.

[0057] In the above embodiments, when transmitting fault location, the first controller identifies the fault location signal transmitted by the upper-level circuit through the identification circuit, updates the fault location signal based on the fault detection result of the battery pack, and controls the transmission circuit to output the updated fault location signal and transmit it to the signal input terminal of the lower-level circuit, thereby realizing the transmission of fault location and thus realizing the location of fault location.

[0058] In some embodiments, the fault location signal is a pulse signal, which includes multiple pulse cycles. Each pulse cycle corresponds to a battery pack, and the sequence number of the pulse cycle corresponds to the cascade position of the battery pack. The level state of each pulse cycle is used to characterize the fault detection result of the corresponding battery pack.

[0059] For example, suppose there are N (N is an integer greater than 1) battery packs cascaded together, and correspondingly, refer to... Figure 2 The pulse signal consists of N pulse cycles, with the first pulse cycle corresponding to the first battery pack, the second pulse cycle to the second battery pack, and so on, with the Nth pulse cycle corresponding to the Nth battery pack. The level of each pulse cycle characterizes the fault detection result of the corresponding battery pack. For example, when the level of the pulse cycle is low, the fault detection result of the corresponding battery pack is faulty; when the level of the pulse cycle is high, the fault detection result of the corresponding battery pack is normal. Figure 2 As shown, based on the pulse signal, it can be determined that the first, fifth, and sixth battery packs are all faulty, thus enabling the location of the fault.

[0060] It should be noted that during fault location transmission, the number of pulse cycles in the transmitted pulse signal increases progressively. For example, the pulse signal transmitted by the first battery pack includes only one pulse cycle characterizing its own fault detection result, i.e., the first pulse cycle; the pulse signal transmitted by the second battery pack includes not only one pulse cycle characterizing its own fault detection result, but also the pulse signal transmitted by the first battery pack, thus the pulse signal transmitted by the second battery pack includes the first pulse cycle and the second pulse cycle; ...; and so on, the pulse signal transmitted by the Nth battery pack includes the first to the Nth pulse cycles.

[0061] In the above embodiments, the fault location can be transmitted and located by pulse transmission, which is simple and highly reliable.

[0062] In some embodiments, refer to Figure 3The transmission circuit 120 includes a first power supply Power1 and a switching circuit 121. The first power supply Power1 is connected to the signal output terminal OUT of the battery pack through the switching circuit 121. The first controller 130 is connected to the control terminal of the switching circuit 121 and is used to control the switching circuit 121 to turn on or off in order to output an updated fault location signal.

[0063] It should be noted that the first power supply Power1 is the signal source for the current battery pack. The switching circuit 121 can be turned on or off. By turning the switching circuit 121 on or off, the connection or disconnection between the first power supply Power1 and the signal output terminal OUT of the current battery pack can be controlled. When connected, the transmission circuit 120 can output a high-level signal. When disconnected, the transmission circuit 120 can output a low-level signal. Thus, the updated fault location signal can be transmitted to the next-level circuit through the transmission circuit 120.

[0064] For example, using the updated fault location signal as... Figure 2 Taking the pulse signal shown as an example, assuming the current battery pack is the eighth battery pack, the first controller 130 will receive a pulse signal containing the first to eighth pulse cycles. The first controller 130 then controls the switching circuit 121 to turn on or off based on this pulse signal. Specifically, in the first pulse cycle, the first controller 130 controls the switching circuit 121 to turn off, making the signal output terminal OUT of the current battery pack low; in the second pulse cycle, the first controller 130 controls the switching circuit 121 to turn on, making the signal output terminal OUT of the current battery pack high; and so on. In the eighth pulse cycle, the first controller 130 controls the switching circuit 121 to turn on, making the signal output terminal OUT of the current battery pack high. Thus, by controlling the on / off state of the switching circuit, the updated fault location signal is transmitted to the signal input terminal of the next-level circuit.

[0065] It should be noted that the on or off duration of the switching circuit 121 is consistent with the pulse period.

[0066] In the above embodiments, the pulse signal can be sent by controlling the output of the first power supply through a switching circuit, thereby realizing the transmission of the fault location. The method is simple and highly reliable.

[0067] In some embodiments, refer to Figure 4The switching circuit 121 includes: a first optocoupler U1 and a first switch K1. The first end of the first optocoupler U1 is connected to the second power supply VCC2 through the first switch K1. The second end of the first optocoupler U1 is grounded to GND1. The third end of the first optocoupler U1 is connected to the first power supply Power1. The fourth end of the first optocoupler U1 is connected to the signal output terminal OUT of the battery pack. The first controller 130 is connected to the control terminal of the first switch K1 and is used to control the first switch K1 to be turned on or off, so as to control the switching circuit 121 to be turned on or off to output the updated fault location signal.

[0068] It should be noted that the first switch K1 can be a MOSFET, IGBT, etc., and there are no restrictions here. The first terminal of the first optocoupler U1 is the anode of the light-emitting diode, the second terminal of the first optocoupler U1 is the cathode of the light-emitting diode, the third terminal of the first optocoupler U1 is the collector of the transistor, and the fourth terminal of the first optocoupler U1 is the emitter of the transistor.

[0069] For example, using the updated fault location signal as... Figure 2 Taking the pulse signal shown as an example. Assuming the current battery pack is the eighth battery pack, the first controller 130 will receive a pulse signal containing the first to eighth pulse cycles. The first controller 130 then controls the first switch K1 to be turned on or off based on this pulse signal. Specifically, in the first pulse cycle, the first controller 130 controls the first switch K1 to be off, and the corresponding first optocoupler U1 is off, resulting in the current battery pack's signal output terminal OUT being low. In the second pulse cycle, the first controller 130 controls the first switch K1 to be on, and the corresponding first optocoupler U1 is on, resulting in the current battery pack's signal output terminal OUT being high; and so on. In the eighth pulse cycle, the first controller 130 controls the first switch K1 to be on, and the corresponding first optocoupler U1 is on, resulting in the current battery pack's signal output terminal OUT being high. Thus, by controlling the on / off state of the first switch, and consequently the optocoupler, the updated fault location signal is transmitted to the signal input terminal of the next-level circuit.

[0070] It should be noted that the on or off duration of the first switch K1 is consistent with the pulse period.

[0071] In the above embodiments, by controlling the first switch to be on or off, the first optocoupler can be controlled to be on or off, thereby not only controlling whether the first power supply is output and realizing the transmission of fault location signals, but also the first optocoupler has a signal isolation function.

[0072] In some embodiments, refer to Figure 5The switching circuit 121 includes: a first optocoupler U1 and a second switch K2. The first end of the first optocoupler U1 is connected to the second power supply VCC2, the second end of the first optocoupler U1 is grounded through the second switch K2, the third end of the first optocoupler U1 is connected to the first power supply Power1, and the fourth end of the first optocoupler U1 is connected to the signal output terminal OUT of the battery pack. The first controller 130 is connected to the control terminal of the second switch K2 and is used to control the second switch K2 to be turned on or off, so as to control the switching circuit 121 to be turned on or off to output the updated fault location signal.

[0073] It should be noted that the second switch K2 can be a MOSFET, IGBT, etc., and there are no restrictions here.

[0074] For example, using the updated fault location signal as... Figure 2 Taking the pulse signal shown as an example. Assuming the current battery pack is the eighth battery pack, the first controller 130 will receive a pulse signal containing the first to eighth pulse cycles. The first controller 130 then controls the second switch K2 to be turned on or off based on this pulse signal. Specifically, in the first pulse cycle, the first controller 130 controls the second switch K2 to be off, and the corresponding first optocoupler U1 is off, resulting in the current battery pack's signal output terminal OUT being low. In the second pulse cycle, the first controller 130 controls the second switch K2 to be on, and the corresponding first optocoupler U1 is on, resulting in the current battery pack's signal output terminal OUT being high; and so on. In the eighth pulse cycle, the first controller 130 controls the second switch K2 to be on, and the corresponding first optocoupler U1 is on, resulting in the current battery pack's signal output terminal OUT being high. Thus, by controlling the on / off state of the first switch, and consequently the optocoupler, the updated fault location signal is transmitted to the signal input terminal of the next-level circuit.

[0075] It should be noted that the on or off duration of the second switch K2 is consistent with the pulse period.

[0076] In the above embodiments, by controlling the second switch to be on or off, the first optocoupler can be controlled to be on or off, thereby not only controlling whether the first power supply is output and realizing the transmission of fault location signals, but also the first optocoupler has a signal isolation function.

[0077] In some embodiments, refer to Figure 6The switching circuit 121 includes: a first optocoupler U1, a first switch K1, and a second switch K2. The first end of the first optocoupler U1 is connected to the output end of the identification circuit 120. The first end of the first optocoupler U1 is also connected to the second power supply VCC2 through the first switch K1. The second end of the first optocoupler U1 is grounded to GND1 through the second switch K2. The third end of the first optocoupler U1 is connected to the first power supply Power1. The fourth end of the first optocoupler U1 is connected to the signal output end OUT of the battery pack. The first controller 130 is connected to the control ends of the first switch K1 and the second switch K2 respectively, and is used to control the first switch K1 and the second switch K2 to be turned on or off, so as to control the switching circuit 121 to be turned on or off to output the updated fault location signal.

[0078] Continue to refer to Figure 6 The switching circuit 121 also includes a first resistor R1, which is connected in series between the first terminal of the first optocoupler U1 and the output terminal of the identification circuit 120 for current limiting protection.

[0079] For example, using the updated fault location signal as... Figure 2 Taking the pulse signal shown as an example. Assuming that the current battery pack is the eighth battery pack, the first controller 130 will obtain a pulse signal containing the first pulse cycle to the eighth pulse cycle, and then the first controller 130 will control the first switch K1 and the second switch K2 to be turned on or off based on the pulse signal.

[0080] Specifically, the first switch K1 can be continuously turned on, and the second switch K2 can be turned on and off. For example, in the first pulse cycle, the first controller 130 controls the second switch K2 to turn off, and the corresponding first optocoupler U1 is turned off, so the current signal output terminal OUT of the battery pack is at a low level; in the second pulse cycle, the first controller 130 controls the second switch K2 to turn on, and the corresponding first optocoupler U1 is turned on, so the current signal output terminal OUT of the battery pack is at a high level; ...; and so on, in the eighth pulse cycle, the first controller 130 controls the second switch K2 to turn on, and the corresponding first optocoupler U1 is turned on, so the current signal output terminal OUT of the battery pack is at a high level. Thus, by controlling the first switch to remain on and the second switch to turn on or off, the optocoupler is controlled to turn on or off, so that the updated fault location signal is transmitted to the signal input terminal of the next-level circuit.

[0081] In the above embodiments, by controlling the first switch and the second switch to be on or off, the first optocoupler can be controlled to be on or off. This not only controls whether the first power supply is output and realizes the transmission of fault location signals, but also the first optocoupler has a signal isolation function.

[0082] In some embodiments, refer to Figures 7-9The identification circuit 110 includes: a second optocoupler U2, the first end of the second optocoupler U2 serving as the input terminal of the identification circuit 110, the second end of the second optocoupler U2 grounded to GND2, the third end of the second optocoupler U2 connected to the second power supply VCC2, and the fourth end of the second optocoupler U2 serving as the output terminal of the identification circuit 110.

[0083] Continue to refer to Figures 7-9 The identification circuit 110 also includes a second resistor R2, one end of which is connected to the first end of the second optocoupler U2, and the other end of which serves as the input terminal of the identification circuit 110 for current limiting protection.

[0084] It should be noted that the first end of the second optocoupler U2 is the anode of the light-emitting diode, the second end of the second optocoupler U2 is the cathode of the light-emitting diode, the third end of the second optocoupler U2 is the collector of the transistor, and the fourth end of the second optocoupler U2 is the emitter of the transistor.

[0085] For example, refer to Figure 7 When the upper-level circuit transmits the corresponding fault location signal, such as a pulse signal, to the signal input terminal IN of the current battery pack, if the fault location signal includes a high-level signal, the second optocoupler U2 is turned on, and the voltage at the fourth terminal of the second optocoupler U2 is the same as the voltage at the third terminal. The sampling terminal of the first controller 130 will sample the high-level signal. If the fault location signal includes a low-level signal, the second optocoupler U2 is turned off, and the voltage at the fourth terminal of the second optocoupler U2 is low. The sampling terminal of the first controller 130 will sample the low-level signal.

[0086] Thus, the identification circuit can identify the fault location signal transmitted by the upper-level circuit, and because a second optocoupler is used, it has a signal isolation function; at the same time, the identification circuit can also identify the fault signal transmitted by the upper-level circuit for fault transmission (the specific details will be described in detail below).

[0087] In some embodiments, the first controller 130 is further configured to transmit a fault before transmitting the fault location, and during fault transmission, if the identification circuit 110 identifies a fault in the upper-level circuit and / or the fault detection result of the battery pack is a fault, control the transmission circuit 120 to output a fault signal and transmit it to the signal input terminal of the lower-level circuit.

[0088] It should be noted that faults in the upper-level circuit include open circuit faults between the current battery pack and the upper-level circuit, as well as faults in the upper-level circuit itself, such as faults in the upper-level battery pack. In other words, when a fault in the upper-level circuit is detected by the identification circuit 110, the first controller 130 can control the transmission circuit 120 to output a fault signal to transmit the fault to the lower-level circuit; or, when a fault occurs in the current battery pack, the first controller 130 can control the transmission circuit 120 to output a fault signal to transmit the fault to the lower-level circuit; or, when both a fault in the upper-level circuit and a fault in the current battery pack are detected by the identification circuit 110, the first controller 130 can control the transmission circuit 120 to output a fault signal to transmit both the fault in the upper-level circuit and the fault in the current battery pack to the lower-level circuit.

[0089] In other words, whether it is a fault in the upstream circuit, a fault in the current battery pack, or a fault in both, a fault signal can be output through the transmission circuit 120 to transmit the fault.

[0090] For example, refer to Figure 7 Under normal circumstances, when the upper-level circuit transmits a high-level signal, the second optocoupler U2 is turned on, and the first controller 130 samples the high-level signal; the first switch K1 is turned on, the first optocoupler U1 is turned on, and the signal output terminal OUT of the current battery pack outputs a high-level signal. Suppose a disconnection fault occurs between the upper-level circuit and the current battery pack, preventing the high-level signal from being transmitted to the signal input terminal IN of the current battery pack; or, the upper-level circuit malfunctions and transmits a low-level signal to the signal input terminal IN of the current battery pack. In this case, the second optocoupler U2 is turned off, the first controller 130 samples the low-level signal, and the first controller 130 controls the first switch K1 to turn off, the first optocoupler U1 is turned off, and the signal output terminal OUT of the current battery pack outputs a low-level signal, which is then transmitted to the signal input terminal of the lower-level circuit. Thus, in the event of a disconnection fault or a battery pack fault, rapid fault transmission can be achieved through the identification circuit 110, the transmission circuit 120, and the first controller 130.

[0091] It should be noted that, Figure 8 The fault propagation process shown in the example is similar to Figure 7 The examples shown are the same, the difference being that in Figure 8 The second switch K2 is used to control the on / off state of the circuit; the details will not be elaborated here. Figure 9 The fault propagation process shown in the example can be compared with... Figure 7 The examples shown are the same, the difference being that in Figure 9 The process involves controlling the on / off state of the first switch K1 and the second switch K2, which will not be elaborated here.

[0092] In the above embodiments, based on the identification circuit, the transmission circuit, and the first controller, the rapid transmission of fault signals, including open circuit faults and battery pack faults, can be achieved.

[0093] In some embodiments, before transmitting the fault location, the identification circuit 110 is also used to receive the fault signal from the upper-level circuit and transmit it to the signal input terminal of the lower-level circuit through the transmission circuit 120 for fault transmission.

[0094] It should be noted that in this example, when transmitting faults in the upper-level circuit, the faults can be transmitted directly through the identification circuit 110 and the transmission circuit 120 without the involvement of the first controller 130.

[0095] For example, refer to Figure 9 Under normal circumstances, when the upper-level circuit transmits a high-level signal, the second optocoupler U2 is turned on; when the first switch K1 is turned off and the second switch K2 is turned on, the first optocoupler U1 is turned on, and the current battery pack's signal output terminal OUT outputs a high-level signal.

[0096] Suppose a disconnection occurs between the upstream circuit and the current battery pack, preventing the high-level signal from the upstream circuit from being transmitted to the signal input terminal IN of the current battery pack. Alternatively, if the upstream circuit malfunctions and transmits a low-level signal to the signal input terminal IN of the current battery pack, then the second optocoupler U2 and the first optocoupler U1 disconnect. The signal output terminal OUT of the current battery pack outputs a low-level signal, which is then transmitted to the signal input terminal of the downstream circuit. Thus, in the event of a fault in the upstream circuit, the fault can be quickly transmitted through the identification circuit 110 and the transmission circuit 120, without the need for the first controller 130.

[0097] When the current battery pack fails, the first controller 130 controls the second switch K2 to open, the first optocoupler U1 to open, and the signal output terminal OUT of the current battery pack outputs a low-level signal, which is then transmitted to the signal input terminal of the next-level circuit. Thus, when the current battery pack fails, the fault can be quickly transmitted through the identification circuit 110, the transmission circuit 120, and the first controller 130.

[0098] In the above embodiments, the identification circuit and the transmission circuit enable the fault of the upper-level circuit to be directly transmitted to the lower-level circuit; the identification circuit, the transmission circuit and the first controller enable the fault of the current battery pack to be transmitted to the lower-level circuit.

[0099] To enable those skilled in the art to more clearly understand the signal circuit of this application, the following describes two cascaded battery packs, each battery pack including... Figure 9 The following explanation uses the signal circuit shown as an example.

[0100] Reference Figure 10The battery management unit may include a third power source (Power), a second controller, and a sampling circuit consisting of a third resistor R3 and a fourth resistor R4 connected in series. The third power source (Power) serves as the signal source; the second controller is used to sample and obtain fault signals and fault location signals transmitted by the battery pack through the sampling circuit, and to process these signals.

[0101] Under normal circumstances, the third power supply, Power, is transmitted through the signal output terminal OUT of the battery management unit, first passing through battery pack #1 connected to it. If there is no open circuit fault in the line between the signal output terminal OUT of the battery management unit and the signal input terminal IN of battery pack #1, and the third power supply, Power, is functioning normally, the second optocoupler U2 of battery pack #1 is turned on. If battery pack #1 is functioning normally, the first switch K1 of battery pack #1 is open, the second switch K2 is on, and the first optocoupler U1 is on, allowing the first power supply, Power1, to be transmitted through the signal output terminal OUT of battery pack #1 to the signal input terminal IN of battery pack #2. If there is no open circuit fault in the line between battery pack #1 and battery pack #2, the second optocoupler U2 of battery pack #2 is on. If battery pack #2 is functioning normally, the first switch K1 of battery pack #2 is open, the second switch K2 is on, and the first optocoupler U1 is on, allowing the first power supply, Power1, to be transmitted through the signal output terminal OUT of battery pack #2 to the signal input terminal IN of the battery management unit. The second controller in the battery management unit samples a high-level signal through its sampling circuit, indicating that there is currently no fault, and the second controller does not perform any fault handling.

[0102] In the event of a broken line or a power supply failure in the line between the signal output terminal OUT of the battery management unit and the signal input terminal IN of battery pack #1, the second optocoupler U2 of battery pack #1 will disconnect, the first optocoupler U1 will disconnect, and the first power supply Power1 will stop transmitting power from the signal output terminal OUT of battery pack #1 to the signal input terminal IN of battery pack #2. Alternatively, if there is no broken line between the signal output terminal OUT of the battery management unit and the signal input terminal IN of battery pack #1, and the third power supply Power is normal, the second optocoupler U2 of battery pack #1 will be on. If battery pack #1 is faulty at this time, the first controller 130 will control the second switch K2 to disconnect, the first optocoupler U1 will disconnect, and the first power supply Power1 will stop transmitting power from the signal output terminal OUT of battery pack #1 to the signal input terminal IN of battery pack #2. Alternatively, if there is a break in the line between the signal output terminal OUT of the battery management unit and the signal input terminal IN of battery pack #1, or if there is a third power supply failure, the second optocoupler U2 of battery pack #1 will disconnect, and the first optocoupler U1 will disconnect. Simultaneously, if battery pack #1 is faulty, the first controller 130 will control the second switch K2 to disconnect, and the first optocoupler U1 will disconnect. Ultimately, the first power supply Power1 will stop transmitting power from the signal output terminal OUT of battery pack #1 to the signal input terminal IN of battery pack #2. In all three scenarios, if there is no break in the line between battery pack #1 and battery pack #2, the second optocoupler U2 of battery pack #2 will disconnect because the first power supply Power1 of battery pack #1 will stop transmitting power. If there is a break in the line between battery pack #1 and battery pack #2, regardless of whether battery pack #1 stops transmitting power, the second optocoupler U2 of battery pack #2 will disconnect because the first power supply Power1 of battery pack #1 cannot continue to be transmitted due to the break in the line. When the second optocoupler U2 of battery pack #2 is disconnected, the first optocoupler U1 is also disconnected, and the first power supply Power1 stops transmitting signals from the signal output terminal OUT of battery pack #2 to the signal input terminal IN of the battery management unit. Simultaneously, if battery pack #2 malfunctions, the first controller 130 of battery pack #2 controls the second switch K2 to disconnect, the first optocoupler U1 is disconnected, and the first power supply Power1 stops transmitting signals from the signal output terminal OUT of battery pack #2 to the signal input terminal IN of the battery management unit. The second controller in the battery management unit samples a low-level signal through the sampling circuit, indicating a possible open circuit fault or battery pack fault. In this case, the second controller performs fault handling.

[0103] Since faults need to be transmitted quickly in order to enable rapid response to faults, such as protection and control, while fault locations do not need to be transmitted quickly and are mainly used for fault diagnosis, the fault location can be transmitted at a fixed time after the fault is transmitted or after receiving the fault location transmission command from the battery management unit, and then each battery pack can transmit the fault location.

[0104] Assuming there is a broken line fault or an abnormality in the third power supply (Power) between the signal output terminal OUT of the battery management unit and the signal input terminal IN of battery pack #1, or if battery pack #1 malfunctions, the first controller 130 of battery pack #1 will determine the fault location signal as a first pulse signal. This first pulse signal includes a first pulse period, and the level of the first pulse period is low. At this time, the first controller 130 controls the first switch K1 to be turned on. Since the first switch K1 is turned on, regardless of whether there is a broken line fault between the signal output terminal OUT of the battery management unit and the signal input terminal IN of battery pack #1, or whether the third power supply (Power) is abnormal, the first optocoupler U1 will receive driving power. At this time, the first controller 130 controls the second switch K2 to be turned off, and the first power supply (Power1) stops being transmitted from the signal output terminal OUT of battery pack #1 to the signal input terminal IN of battery pack #2. At this time, the signal output terminal OUT of battery pack #1 outputs the first pulse signal to battery pack #2.

[0105] Since the first pulse signal is low, the second optocoupler U2 of battery pack #2 is disconnected. The first controller 130 of battery pack #2 will sample a low-level signal, indicating that battery pack #1 has failed. The first controller 130 of battery pack #2 will update the first pulse signal to obtain a second pulse signal based on the fault detection result of battery pack #2. This second pulse signal includes a first pulse cycle and a second pulse cycle. If battery pack #2 has not failed, the level of the first pulse cycle is low, and the level of the second pulse cycle is high. Then, the first controller 130 of battery pack #2 controls the first switch K1 to remain on and controls the second switch K2 to first open and then close. The first power supply Power1 first stops transmitting the signal from the signal output terminal OUT of battery pack #2 to the signal input terminal IN of the battery management unit, and then transmits the signal from the signal output terminal OUT of battery pack #2 to the signal input terminal IN of the battery management unit. At this time, the signal output terminal OUT of battery pack #2 outputs the second pulse signal to the battery management unit. If battery pack #2 malfunctions, the level of the first pulse cycle is low, and the level of the second pulse cycle is also low. Then, the first controller 130 of battery pack #2 controls the first switch K1 to remain on and controls the second switch K2 to be off for two consecutive pulse cycles. The first power supply Power1 stops for two consecutive pulse cycles and transmits the signal to the signal input of the battery management unit through the signal output terminal OUT of battery pack #2. At this time, the signal output terminal OUT of battery pack #2 outputs the second pulse signal to the battery management unit.

[0106] The second controller in the battery management unit samples the second pulse signal through a sampling circuit. Based on the second pulse signal, the faulty battery pack can be determined, thereby locating the fault.

[0107] It should be noted that if the second pulse signals sampled by the second controller of the battery management unit are all low-level signals, it indicates that the current fault is a disconnection fault.

[0108] It should be noted that the signal circuit of this application can also be applied to the cascading of three or more battery packs, such as... Figure 11 As shown, each battery pack includes Figure 9 The signal circuit shown describes its operation process as follows: Figure 10 The circuit shown operates in the same way and will not be described again. Additionally, each battery pack may also include... Figure 8 or Figure 7 The signal circuit shown can be referenced from the previous description in terms of its operation process, and will not be repeated here.

[0109] In summary, the technical solution of this application embodiment can not only realize the rapid transmission of wire breakage faults and battery pack faults, but also realize the location of the fault when the battery pack fails.

[0110] In one embodiment, a battery system is provided.

[0111] Figure 12 This is a schematic diagram of a battery system according to an embodiment of this application.

[0112] Reference Figure 12 The battery system includes a first battery pack #1, a second battery pack #2, and a battery management unit 200. Both the first battery pack #1 and the second battery pack #2 include the aforementioned signal circuits. The signal output terminal OUT of the first battery pack #1 is connected to the signal input terminal IN of the second battery pack #2. The signal output terminal OUT of the battery management unit 200 is connected to the signal input terminal IN of the first battery pack #1, and the signal input terminal IN of the battery management unit 200 is connected to the signal output terminal of the second battery pack #2. The battery management unit 200 receives fault signals and fault location signals transmitted from the second battery pack #2, and performs protection control based on the fault signals and determines the faulty battery pack based on the fault location signals.

[0113] In some embodiments, refer to Figure 13 The battery system also includes at least one third battery pack #3, which is cascaded between the signal output terminal of the first battery pack #1 and the signal input terminal of the second battery pack #2, and each third battery pack #3 includes the aforementioned signal circuit.

[0114] In some embodiments, refer to Figures 12-13 The battery management unit 200 includes a third power supply, Power, which is connected to the signal output terminal OUT of the battery management unit 200.

[0115] In some embodiments, refer to Figures 12-13 The battery management unit 200 includes a second controller 210 and a sampling circuit 220. The input terminal of the sampling circuit 220 is connected to the signal input terminal IN of the battery management unit 200, and the output terminal of the sampling circuit 220 is connected to the second controller 210. The second controller 210 is used to sample the voltage of the signal input terminal IN of the battery management unit 200 through the sampling circuit 220 to obtain the fault signal and fault location signal transmitted by the second battery pack #2.

[0116] It should be noted that for details regarding the battery system 200, please refer to the relevant instructions on the signal circuit; these will not be repeated here.

[0117] In one embodiment, an energy storage system is provided, including the aforementioned signal circuit or battery system.

[0118] In one embodiment, a vehicle is provided, including the aforementioned signal circuitry or battery system.

[0119] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and they should all be covered within the scope of the claims and specification of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. 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 signal circuit for a cascaded battery pack, characterized in that, include: An identification circuit is provided, wherein the input terminal of the identification circuit is connected to the signal input terminal of the battery pack, the signal input terminal of the battery pack is adapted to be connected to the signal output terminal of the upper-level circuit, and the output terminal of the identification circuit is connected to the first controller; wherein the upper-level circuit is the signal circuit of the upper-level battery pack or the battery management unit. A transmission circuit is provided, the output terminal of which is connected to the signal output terminal of the battery pack. The signal output terminal of the battery pack is adapted to connect to the signal input terminal of a lower-level circuit. The control terminal of the transmission circuit is connected to the first controller. The lower-level circuit is either the signal circuit of the lower-level battery pack or the battery management unit. Specifically, when transmitting the fault location, the first controller identifies the fault location signal transmitted by the upper-level circuit through the identification circuit, updates the fault location signal based on the fault detection result of the battery pack, and controls the transmission circuit to output the updated fault location signal and transmit it to the signal input terminal of the lower-level circuit.

2. The circuit according to claim 1, characterized in that, The fault location signal is a pulse signal, which includes multiple pulse cycles. Each pulse cycle corresponds to a battery pack, and the sequence number of the pulse cycle corresponds to the cascade position of the battery pack. The level state of each pulse cycle is used to characterize the fault detection result of the corresponding battery pack.

3. The circuit according to claim 2, characterized in that, The transmission circuit includes: a first power supply and a switching circuit, wherein the first power supply is connected to the signal output terminal of the battery pack through the switching circuit; wherein the first controller is connected to the control terminal of the switching circuit and is used to control the switching circuit to be turned on or off to output the updated fault location signal.

4. The circuit according to claim 3, characterized in that, The switching circuit includes: a first optocoupler and a first switch. The first end of the first optocoupler is connected to a second power supply through the first switch. The second end of the first optocoupler is grounded. The third end of the first optocoupler is connected to the first power supply. The fourth end of the first optocoupler is connected to the signal output terminal of the battery pack. The first controller is connected to the control terminal of the first switch and is used to control the first switch to be turned on or off, so as to control the switching circuit to be turned on or off to output the updated fault location signal.

5. The circuit according to claim 3, characterized in that, The switching circuit includes: a first optocoupler and a second switch. A first end of the first optocoupler is connected to a second power supply, a second end of the first optocoupler is grounded through the second switch, a third end of the first optocoupler is connected to the first power supply, and a fourth end of the first optocoupler is connected to the signal output terminal of the battery pack. The first controller is connected to the control terminal of the second switch and is used to control the second switch to be turned on or off, so as to control the switching circuit to be turned on or off to output the updated fault location signal.

6. The circuit according to claim 3, characterized in that, The switching circuit includes: a first optocoupler, a first switch, and a second switch. The first end of the first optocoupler is connected to the output end of the identification circuit. The first end of the first optocoupler is also connected to a second power supply through the first switch. The second end of the first optocoupler is grounded through the second switch. The third end of the first optocoupler is connected to the first power supply. The fourth end of the first optocoupler is connected to the signal output end of the battery pack. The first controller is connected to the control ends of the first switch and the second switch respectively, and is used to control the first switch and the second switch to be turned on or off, so as to control the switching circuit to be turned on or off to output the updated fault location signal.

7. The circuit according to claim 6, characterized in that, The switching circuit further includes a first resistor, which is connected in series between the first end of the first optocoupler and the output end of the identification circuit.

8. The circuit according to any one of claims 1-7, characterized in that, The identification circuit includes: a second optocoupler, the first end of which serves as the input terminal of the identification circuit, the second end of which is grounded, the third end of which is connected to a second power supply, and the fourth end of which serves as the output terminal of the identification circuit.

9. The circuit according to claim 8, characterized in that, The identification circuit further includes a second resistor, one end of which is connected to the first end of the second optocoupler, and the other end of which serves as the input terminal of the identification circuit.

10. The circuit according to any one of claims 1-7, characterized in that, The first controller is also used to transmit faults before transmitting the fault location, and during fault transmission, if the identification circuit identifies a fault in the upper-level circuit and / or the fault detection result of the battery pack is a fault, the controller controls the transmission circuit to output a fault signal and transmit it to the signal input terminal of the lower-level circuit.

11. The circuit according to claim 6 or 7, characterized in that, Before transmitting the fault location, the identification circuit is also used to receive the fault signal from the upper-level circuit and transmit it to the signal input terminal of the lower-level circuit through the transmission circuit to transmit the fault.

12. A battery system, characterized in that, include: A first battery pack and a second battery pack, both the first battery pack and the second battery pack include a signal circuit according to any one of claims 1-11, wherein the signal output terminal of the first battery pack is connected to the signal input terminal of the second battery pack; A battery management unit, wherein the signal output terminal of the battery management unit is connected to the signal input terminal of the first battery pack, and the signal input terminal of the battery management unit is connected to the signal output terminal of the second battery pack, for receiving fault signals and fault location signals transmitted by the second battery pack, and performing protection control based on the fault signals and determining the faulty battery pack based on the fault location signals.

13. The system according to claim 12, characterized in that, Also includes: At least one third battery pack, wherein the at least one third battery pack is cascaded between the signal output terminal of the first battery pack and the signal input terminal of the second battery pack, and each third battery pack includes a signal circuit according to any one of claims 1-11.

14. The system according to claim 12 or 13, characterized in that, The battery management unit includes a third power source, which is connected to the signal output terminal of the battery management unit.

15. The system according to claim 12 or 13, characterized in that, The battery management unit includes a second controller and a sampling circuit. The input terminal of the sampling circuit is connected to the signal input terminal of the battery management unit, and the output terminal of the sampling circuit is connected to the second controller. The second controller is used to sample the voltage of the signal input terminal of the battery management unit through the sampling circuit to obtain the fault signal and fault location signal transmitted by the second battery pack.

16. An energy storage system, characterized in that, It includes the signal circuit according to any one of claims 1-11, or the battery system according to any one of claims 12-15.

17. A vehicle, characterized in that, It includes the signal circuit according to any one of claims 1-11, or the battery system according to any one of claims 12-15.

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