Battery management system and energy storage system

Abstract

Relates to the technical field of batteries, for example to a battery management system (1000) and an energy storage system (1). A battery management system (1000) includes N detection modules (100), a switching circuit (200), a voltage converter (300), and a controller (400). The first detection module (100) to the Nth detection module (100) are electrically connected in sequence, each detection module (100) is configured to be electrically connected with a battery unit (2000), and the first detection module (100) is configured to be capable of outputting a first signal when any battery unit (2000) is abnormal when the battery management system (1000) is in a sleep mode. The switching circuit (200) is configured to be turned on in response to a first signal. The voltage converter (300) is configured to reduce the voltage output by the external power supply based on conduction of the switching circuit (200) and supply power to the controller (400) so as to wake up the battery management system (1000). As the detection modules (100) are electrically connected in sequence, when more battery units (2000) need to be connected in series in the energy storage system (1), only the detection modules (100) need to be correspondingly connected in series in the battery management system (1000), and the expandability of the BMS (1000) is improved.

Description

Battery management system and energy storage system Technical Field

[0001] The embodiments of the present application relate to the field of battery technology, and in particular to a battery management system and an energy storage system. Background Art

[0002] A battery energy storage system is a device that converts external energy into electrical energy and stores it internally to power other devices when needed. A battery management system (BMS) is a system used to manage and protect energy storage systems. It can include multiple detection modules for fault detection of corresponding battery cells or battery cell modules. When a detection module detects a fault, the BMS takes protective measures to prevent damage to the energy storage system. Regarding the expansion of battery cells or battery cell modules, the current BMS has the problem of poor scalability of detection modules.

[0003] Summary of the Invention

[0004] The embodiments of the present application provide a battery management system and an energy storage system, which can improve the scalability of the battery management system.

[0005] In a first aspect, embodiments of the present application provide a battery management system comprising N detection modules, a switching circuit, a voltage converter, and a controller. The first detection module through the Nth detection module are electrically connected in sequence, each detection module being configured to be electrically connected to a battery cell. The first detection module is configured to output a first signal when an abnormality occurs in any battery cell when the battery management system is in sleep mode.

[0006] The switch circuit is electrically connected to the first detection module and is configured to turn on the switch circuit in response to the first detection module outputting the first signal. The voltage converter is electrically connected to the switch circuit and the controller, respectively. The voltage converter is configured to step down the voltage output by the external power supply and output the voltage based on the switching circuit being turned on. The output voltage is used to power the controller to wake up the battery management system.

[0007] Wherein, N is a positive integer ≥ 2, and the abnormality includes abnormal temperature and / or abnormal voltage of the battery cell.

[0008] Specifically, in some embodiments, the N-1th detection module is configured to: send a first signal when the corresponding battery cell is detected to be abnormal when the battery management system is in sleep mode, and send a first signal after receiving the first signal sent by the adjacent Nth detection module.

[0009] Optionally, each detection module includes a first connector, and adjacent detection modules can be electrically connected via the first connector. The Nth detection module is configured to be electrically connected to the N+1th detection module via the first connector. The provision of the first connector facilitates expansion of detection modules and battery cells.

[0010] Optionally, each detection module includes a second connector and a third connector. The detection module can be electrically connected to the previous detection module via the second connector and to the next detection module via the third connector. The Nth detection module is configured to be electrically connected to the N+1th detection module via the second connector. The provision of the second and third connectors facilitates the expansion of detection modules and battery cells.

[0011] In some embodiments, each of the detection modules includes a sampling circuit and a detection unit, and any of the second to Nth detection modules further includes a signal transmission circuit. The detection unit includes a first connection terminal and a second connection terminal, and is electrically connected to the sampling circuit to obtain the voltage signal and / or temperature signal of the battery cell through the sampling circuit.

[0012] Each of the signal transmission circuits is electrically connected to the second connection end of the Mth detection unit and to the first connection end of the M-1th detection unit, and is used to transmit the first signal between adjacent detection units, where M is a positive integer from 2 to N.

[0013] In other embodiments, each of the detection units further includes a third connection terminal.

[0014] The signal transmission circuit includes a first switch and a first isolation element. The first isolation element includes an input terminal and an output terminal. The first terminal of the first switch is electrically connected to the third connection terminal of the Mth detection unit, the second terminal of the first switch is electrically connected to the input terminal of the first isolation element, the third terminal of the first switch is electrically connected to the second connection terminal of the Mth detection unit, and the input terminal of the first isolation element is also electrically connected to the Mth reference ground.

[0015] The output end of the first isolation element is electrically connected to the first connection end and the third connection end of the M-1th detection unit respectively, and the output end of the first isolation element is also electrically connected to the M-1th reference ground.

[0016] The signal transmission circuit adopts the first isolation element, which can isolate the signal transmission and improve the safety of the BMS.

[0017] In some other embodiments, the signal transmission circuit further includes a first resistor, a second resistor, a third resistor, and a fourth resistor. A first end of the first resistor is electrically connected to the third connection terminal of the Mth detection unit, and a second end is electrically connected to the third end of the first switch. A first end of the second resistor is electrically connected to the second connection terminal of the Mth detection unit, and a second end is electrically connected to the second end of the first resistor and the third end of the first switch, respectively.

[0018] The first end of the third resistor is electrically connected to the third connection terminal of the M-1 detection unit, and the second end is electrically connected to the output terminal of the first isolation element. The first end of the fourth resistor is electrically connected to the second end of the third resistor and the output terminal of the first isolation element, respectively, and the second end is electrically connected to the first connection terminal of the M-1 detection unit.

[0019] In some embodiments, the third connection terminal is used to output a voltage signal, and the first switch is configured to be turned on in response to the second connection terminal of the detection unit generating a first signal based on the voltage signal output by the third connection terminal.

[0020] In some embodiments, the switch circuit includes a second switch, a second isolation element, a third isolation element, and an energy storage element.

[0021] The second isolation element and the third isolation element each include an input end and an output end, the first end of the second switch is electrically connected to the third connection end of the first detection unit, the second end of the second switch is electrically connected to the input end of the second isolation element, the input end of the second isolation element is also electrically connected to the first reference ground, and the third end of the second switch is electrically connected to the second connection end of the first detection unit.

[0022] The output end of the second isolation element is electrically connected to the first end of the energy storage element and the input end of the third isolation element respectively. The second end of the energy storage element is grounded. The input end of the third isolation element is also connected to the ground. The output end of the third isolation element is electrically connected to the voltage converter.

[0023] Due to the arrangement of the second isolation element and the third isolation element, isolation between high voltage and low voltage is achieved, thereby improving the safety of the BMS.

[0024] Optionally, the energy storage element includes a supercapacitor.

[0025] Using an energy storage element (such as a supercapacitor) to provide power to the third isolation element has lower power consumption than using a standby power supply and lower cost than using an external battery.

[0026] In some other embodiments, the switch circuit further includes a fifth resistor and a sixth resistor.

[0027] The first end of the fifth resistor is electrically connected to the third connection end of the first detection unit, and the second end is electrically connected to the third end of the second switch. The first end of the sixth resistor is electrically connected to the second connection end of the first detection unit, and the second end is electrically connected to the second end of the fifth resistor and the third end of the second switch, respectively.

[0028] Optionally, the first switch and the second switch each include at least one of a triode or a field effect transistor, the first isolation element and the second isolation element each include at least one of a photocoupler, a photofield effect transistor, or a thyristor photocoupler, and the third isolation element includes a thyristor photocoupler. The thyristor photocoupler has a strong ability to withstand instantaneous high currents, which can prevent the third isolation element from being damaged and affecting the stability of the BMS when a peak current occurs.

[0029] In some other embodiments, the battery management system further includes a seventh resistor, a first end of the seventh resistor being electrically connected to the output end of the third isolation element, and a second end of the seventh resistor being electrically connected to the voltage converter.

[0030] In other embodiments, the battery management system further includes a third switch electrically connected to the controller and the voltage converter, respectively, and configured to be turned on or off in response to a control signal from the controller. The provision of the third switch can reliably shut down the third isolation element.

[0031] In other embodiments, the battery management system further includes a driving circuit, which is electrically connected to the third switch and the controller, respectively, and is used to receive a control signal from the controller to generate a driving signal, and the third switch can be turned on or off in response to the driving signal.

[0032] In other embodiments, the battery management system further includes a charging circuit, which is electrically connected to the energy storage element and the voltage converter, respectively, and is used to charge the energy storage element.

[0033] In other embodiments, the battery management system further includes a first charging port and / or a second charging port; wherein, the first charging port is configured to connect a USB data cable to charge the energy storage element, and the second charging port is configured to connect an energy storage inverter to charge the energy storage element.

[0034] The USB data cable allows connection to the municipal power supply system or other backup batteries to charge the energy storage element. A second charging port also allows connection to an energy storage converter, allowing external devices 4000 to charge the energy storage element. Multiple charging methods ensure that the energy storage element has power, ensuring the BMS fault wake-up function is implemented.

[0035] In some embodiments, the voltage converter includes a DC-DC converter and a transformer; or, the voltage converter includes a DC-DC converter.

[0036] In other embodiments, the detection module further includes a communication circuit, the communication circuit is electrically connected between adjacent detection modules, and the communication circuit is electrically connected between the first detection module and the controller.

[0037] Optionally, the communication circuit includes at least one of a daisy chain communication circuit, a CAN communication circuit and a 485 communication circuit.

[0038] In a second aspect, an embodiment of the present application further provides an energy storage system, comprising N battery units and the above-mentioned battery management system, wherein each of the battery units comprises a plurality of battery cells.

[0039] Compared with the prior art, the battery management system provided in the embodiment of the present application includes N detection modules electrically connected in sequence. Since the detection modules are electrically connected in sequence to form a series-connected detection chain, when more battery cells need to be connected in series in the energy storage system, it is only necessary to connect the corresponding detection modules in series in the detection chain of the battery management system, thereby improving the scalability of the detection modules and battery cells in the BMS.

[0040] Furthermore, when any battery cell experiences an abnormality, the first detection module outputs a first signal through signal transmission via the series-connected detection chain. The switch circuit conducts in response to the first signal, and based on this conduction, the voltage converter steps down the voltage output by the external power supply, powering the controller and waking it up. Once awakened, the controller can address the battery cell anomaly and implement protective measures, thereby improving the safety of the battery management system and energy storage system. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] One or more embodiments are exemplarily illustrated by pictures in the corresponding drawings. These exemplifications do not constitute limitations on the embodiments. Elements with the same reference numerals in the drawings represent similar elements. Unless otherwise stated, the figures in the drawings do not constitute proportional limitations.

[0042] FIG1 is a schematic structural diagram of an embodiment of an energy storage system of the present application;

[0043] FIG2 is a schematic structural diagram of another embodiment of the energy storage system of the present application;

[0044] FIG3 is a schematic structural diagram of an embodiment of the energy storage system of the present application;

[0045] FIG4 is a schematic structural diagram of an embodiment of a BMS of the present application;

[0046] FIG5 is a schematic structural diagram of an embodiment of a BMS of the present application;

[0047] FIG6 is a schematic structural diagram of an embodiment of a BMS of the present application;

[0048] FIG7 is a schematic structural diagram of an embodiment of a BMS of the present application;

[0049] FIG8 is a schematic structural diagram of an embodiment of a BMS of the present application;

[0050] FIG9 is a schematic diagram of the hardware structure of a signal transmission circuit in one embodiment of the BMS of the present application;

[0051] FIG10 is a schematic structural diagram of an embodiment of a BMS of the present application;

[0052] FIG11 is a schematic structural diagram of an embodiment of a BMS of the present application;

[0053] FIG12 is a schematic diagram of the hardware structure of a switch circuit in one embodiment of the BMS of the present application;

[0054] FIG13 is a schematic diagram of the hardware structure of a switch circuit in one embodiment of the BMS of the present application;

[0055] FIG14 is a schematic diagram showing the connection method of each detection module in an embodiment of the present application. DETAILED DESCRIPTION

[0056] To make the objectives, technical solutions, and advantages of the embodiments of the present application more clear, the technical solutions in the embodiments of the present application will be described in detail below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present application, not all of them. It should be understood that the specific embodiments described herein are only used to explain the present application and are not intended to limit the present application.

[0057] It should be noted that, when an element is referred to as being “connected to” another element, it may be directly connected to the other element, or one or more intervening elements may exist therebetween.

[0058] In addition, the technical features involved in the various embodiments of the present application described below can be combined with each other as long as there is no structural conflict between them.

[0059] A battery energy storage system is a device that converts external energy into electrical energy and stores it internally, allowing it to power other devices when needed. Figure 1 shows the structure of an energy storage system. As shown in Figure 1, energy storage system 1 includes a power module and a BMS 1000. The power module is used to provide electrical energy, and the BMS 1000 is used to detect, manage, and / or protect the power module.

[0060] In which, the power module may include at least two battery cells 2000. In the embodiment shown in Figure 1, the battery cells 2000 are connected in series. In other embodiments, the battery cells 2000 may also be connected in parallel, or a mixed connection of series and parallel may be adopted.

[0061] Each battery unit 2000 may include a single battery cell, or a battery cell module composed of multiple battery cells. The battery cells in the battery cell module may be connected in series, in parallel, or in a mixed manner.

[0062] The BMS 1000 may include at least two detection modules 100, each of which is electrically connected to a battery cell 2000 and configured to detect the voltage and / or temperature of the battery cell 2000. Based on the detected voltage and / or temperature, the BMS 1000 may determine whether the battery cell 2000 is abnormal. In one specific implementation, a battery cell 2000 and a detection module 100 may constitute a battery module a.

[0063] The BMS 1000 further includes a switching circuit 200 , a voltage converter 300 , and a controller 400 . The voltage converter 300 can step down the voltage provided by the power module to power the BMS. Specifically, it can power the controller 400 and other units on the BMS (e.g., a communication unit, etc.).

[0064] The switch circuit 200 is used to connect or disconnect the power module and the voltage converter 300. When the switch circuit 200 performs the on operation and connects the power module and the voltage converter 300, the voltage converter 300 is connected to the positive electrode B+ of the power module and the negative electrode B- of the power module, and the voltage provided by the power module is stepped down to supply power to the BMS.

[0065] When the switch circuit 200 performs the disconnection operation to disconnect the power module and the voltage converter 300 , the voltage converter does not provide the power supply voltage.

[0066] When the voltage converter 300 provides the supply voltage, the BMS (including the controller 400 ) may be in the working mode, and when the voltage converter 300 does not provide the supply voltage, the BMS (including the controller 400 ) is in the sleep mode.

[0067] 2 , in some embodiments, the energy storage system 1 may be electrically connected to an energy storage converter 3000 , which in turn may be electrically connected to an external device 4000 . The external device 4000 is configured to provide electrical energy to the energy storage system 1 , so that the energy storage system 1 stores electrical energy.

[0068] The external device 4000 is, for example, a solar power generation system, a wind power generation system, or a municipal power supply system. The external device 4000 provides AC power, and the energy storage converter 3000 converts the AC power provided by the external device 4000 into DC power to charge the power module.

[0069] In other embodiments, voltage can be provided by other power sources, and the voltage converter 300 can step down the voltage provided by the other power sources to power the BMS. For example, in the embodiment shown in FIG2 , the power supply consisting of the external device 4000 and the energy storage converter 3000 can power the voltage converter 300.

[0070] The voltage converter 300 may also be electrically connected to the energy storage converter 3000 , and may perform voltage reduction processing based on the DC voltage provided by the energy storage converter 3000 to provide a power supply voltage for the BMS.

[0071] As shown in FIG3 , the BMS may further include a switch 500 , which is connected in series in the charge and discharge circuit of the power module. In the embodiment shown in FIG3 , the switch 500 is disposed adjacent to the positive electrode B+ of the battery. In other embodiments, the switch 500 may also be disposed adjacent to the negative electrode B− of the battery.

[0072] The controller 400 is the processing center of the BMS, responsible for performing BMS management and protection functions. For example, it receives fault information from the detection module and performs protection operations based on the fault information. Fault information includes, for example, the identity of the faulty battery cell or the type of fault. Protection operations include, for example, controlling the switch 500 to disconnect the power module's discharge circuit.

[0073] In some embodiments, to reduce the power consumption of the BMS, the BMS is not always in the working mode. When the battery cells are charging and discharging, the BMS is in the working mode. When the battery cells are not charging and discharging, the BMS can be in the sleep mode.

[0074] As described above, the BMS can be placed in either operating mode or sleep mode by operating the switch circuit 200. When the switch circuit 200 is turned on, the voltage converter 300 is electrically connected to an external power source (e.g., the power module formed by the battery cells in FIG1 ). The voltage converter 300 steps down the voltage provided by the external power source to provide a supply voltage for the BMS, and the BMS is in operating mode.

[0075] When the switch circuit 200 is turned off, the electrical connection between the voltage converter 300 and the external power source is disconnected, the voltage converter 300 does not provide a power supply voltage, and the BMS is in a sleep mode.

[0076] However, when the BMS is in sleep mode, the controller 400 is also in sleep mode. If a battery cell fails, for example, the temperature of the battery cell is too high (overtemperature) or the voltage is too high (overvoltage), the controller 400 is in sleep mode and cannot handle the battery cell failure, and the energy storage system is at risk of being damaged.

[0077] In order to handle a battery cell failure when the BMS is in sleep mode, the controller 400 may be awakened when a battery cell failure occurs. That is, the switch circuit 200 is turned on, and the voltage converter 300 provides a supply voltage to wake up the controller 400.

[0078] The detection module 100 can send a wake-up signal to the switch circuit 200, that is, the detection module 100 is set to still detect the temperature and / or voltage of the battery cell 2000 when the BMS is in sleep mode. When the temperature and voltage are abnormal, a wake-up signal is sent to the switch circuit 200 to turn on the switch circuit 200 to wake up the controller 400.

[0079] When the energy storage converter charges the voltage converter 300 , the voltage converter 300 can convert the voltage provided by the energy storage converter 3000 to power the BMS, and can directly wake up the controller 400 .

[0080] The detection modules 100 can be connected in series, with each detection module 100 being electrically connected in sequence, with each detection module being electrically connected to the switch circuit 200 (see FIG4 ). For example, in a case where there are N detection modules, the Nth detection module is electrically connected to the N-1th detection module, the N-1th detection module is electrically connected to the N-2th detection module, ..., the second detection module is electrically connected to the first detection module, and the first detection module is electrically connected to the switch circuit 200.

[0081] In other embodiments, each detection module 100 may be electrically connected to the switch circuit 200, that is, the detection modules 100 are connected in parallel. When the detection modules 100 are connected in series, it is convenient to expand the battery module a. For example, when a battery cell 2000 needs to be added to the power module, the (N+1) detection module can be directly electrically connected to the (N) detection module, thus achieving the expansion of the (N+1) battery module.

[0082] Various embodiments of a BMS that can be applied to the energy storage system 1 are described below.

[0083] An embodiment of the present application provides a BMS, including N detection modules, a switching circuit, a voltage converter and a controller, where N is a positive integer ≥2.

[0084] Among them, each detection module is configured to be electrically connected to a battery unit, the first detection module to the Nth detection module are electrically connected in sequence, the switch circuit is electrically connected to the first detection module, and the voltage converter is electrically connected to the switch circuit and the controller respectively.

[0085] The first detection module is configured to output a first signal when any battery cell experiences an abnormality while the BMS is in sleep mode. The switching circuit is configured to conduct in response to the first detection module outputting the first signal. The voltage converter is configured to step down the voltage output by the external power supply and output the voltage upon the switching circuit being turned on. The output voltage powers the controller to wake up the BMS.

[0086] Since the first detection module to the Nth detection module are electrically connected in sequence, and the first detection module is also electrically connected to the switching circuit, each detection module constitutes a detection chain connected in series. When an abnormality occurs in any battery cell in the sleep mode, the first signal can be transmitted to the first detection module through the detection chain connected in series to turn on the switching circuit, so that the voltage converter performs a voltage reduction process based on the voltage output by the external power supply to power the controller and wake up the BMS.

[0087] The external power source is, for example, a power module composed of battery cells. FIG4 shows a structure of a BMS 1000 using the power module composed of battery cells as an example.

[0088] In the embodiment shown in FIG4 , the detection modules are connected in series, i.e., the Nth detection module is electrically connected to the N-1th detection module, ..., the second detection module is electrically connected to the first detection module, and the first detection module is also electrically connected to the switch circuit 200. Each detection module is electrically connected to a battery cell, i.e., the Nth detection module is electrically connected to battery cell N, ..., the second detection module is electrically connected to battery cell 2, and the first detection module is electrically connected to battery cell 1.

[0089] The switch circuit 200 is electrically connected between the power module and the voltage converter 300 , and the voltage converter 300 is electrically connected to the switch circuit 200 and the controller 400 .

[0090] Specifically, in some embodiments, the detection module 100 is configured to: issue a first signal upon detecting an abnormality in a corresponding battery cell while the BMS is in sleep mode, and to issue a first signal upon receiving the first signal issued by a previous detection module. The switching circuit 200 is configured to connect the power module and the voltage converter 300 in response to the first signal. The voltage converter 300 is configured to, when electrically connected to the power module, step down the voltage output by the power module to provide a supply voltage for the BMS.

[0091] If any battery cell is abnormal, the corresponding detection module sends a first signal. If battery cell 1 is abnormal, the first detection module sends a first signal. In response to the first signal, the switch circuit 200 is turned on, and the voltage converter 300 is electrically connected to the power module to step down the voltage provided by the power module to provide the power supply voltage for the BMS.

[0092] If another battery cell fails, the corresponding detection module issues a first signal. Because each detection module is also configured to issue a first signal upon receiving a first signal from a previous detection module, i.e., it has a signal transmission function, the first detection module is able to receive and issue the first signal through signal transmission from each series-connected detection module. Switch circuit 200 is turned on in response to the first signal, and voltage converter 300 is electrically connected to the power module, stepping down the voltage provided by the power module to provide the power supply voltage for the BMS.

[0093] The first signal is, for example, a low-level signal or a high-level signal. The battery cell abnormality includes abnormal temperature and / or abnormal voltage of the battery cell. The temperature abnormality includes over-temperature or under-temperature of the battery cell, and the voltage abnormality includes over-voltage or under-voltage of the battery cell.

[0094] Taking the embodiment shown in FIG4 as an example, when the switch circuit 200 is disconnected and the BMS is in sleep mode, each detection module 100 detects whether a temperature abnormality and / or a voltage abnormality occurs in the corresponding battery cell. Assuming that the third detection module detects a temperature abnormality in battery cell 3, the third detection module sends a first signal, the second detection module receives the first signal and sends a first signal, and the first detection module receives the first signal and sends a first signal.

[0095] The switch circuit 200 is turned on in response to the first signal sent by the first detection module, the voltage converter 300 is connected to the power module and forms a path, the voltage converter 300 steps down the voltage provided by the power module to power the controller 400, and the BMS is awakened.

[0096] After being awakened, the controller 400 can process the fault of the battery cell, for example, obtain the fault information sent by the detection module, determine the faulty battery cell, and take corresponding protection measures.

[0097] Since, in the embodiment of the present application, the BMS includes N detection modules electrically connected in sequence, each detection module forms a detection chain connected in series. When more battery cells need to be connected in series in the energy storage system, it is only necessary to connect corresponding detection modules in series in the detection chain of the battery management system, thereby improving the scalability of the detection modules and battery cells in the BMS.

[0098] The "previous detection module" refers to the detection module that, based on the signal's direction, first sends the first signal, and the "next detection module" refers to the detection module that, based on the signal's direction, receives the first signal later. Still taking the embodiment shown in Figure 4 as an example, for the second detection module, the third detection module is its previous detection module, and the first detection module is its next detection module. For the first detection module, the second detection module is its previous detection module.

[0099] In some embodiments, to facilitate expansion of the detection modules, each detection module is provided with a first connector, and adjacent detection modules can be electrically connected via the first connector.

[0100] Figure 5 uses three detection modules as an example to illustrate a schematic diagram of the connection of the detection modules via the first connector 101. Specifically, in actual applications, the first connector 101 may include multiple pins or connection terminals, and a detection module may be connected to the previous detection module via some pins or connection terminals, and connected to the next detection module via another portion of pins or connection terminals.

[0101] For example, the first portion of the pins of the first connector of the second detection module is connected to the second portion of the pins of the first connector of the third detection module to achieve a connection between the second and third detection modules. The second portion of the pins of the first connector of the second detection module is connected to the first portion of the pins of the first connector of the first detection module to achieve a connection between the second and first detection modules. The second portion of the pins of the first connector of the first detection module can be connected to other devices in the BMS.

[0102] Each first connector can be connected by a connecting line. When the detection module needs to be expanded, for example, a fourth detection module needs to be added, the second part of the pins of the first connector of the fourth detection module can be directly connected to the first part of the pins of the first connector of the third detection module to realize the connection between the fourth detection module and the third detection module.

[0103] In one specific implementation, each detection module can be provided on a circuit board, which can be referred to as a slave circuit board, while the controller, voltage converter, etc. can be provided on another circuit board, which can be referred to as a master circuit board. The slave circuit boards are electrically connected to each other via a portion of the pins of their respective first connectors. Slave circuit board 1 is connected to slave circuit board 2 via a portion of the pins of its first connector, and is connected to the master circuit board via another portion of the pins of its first connector.

[0104] It can be understood that the above-mentioned “part of the pins or connection terminals” refers to one or more than two pins or connection terminals.

[0105] In other embodiments, please refer to Figure 6, the detection module 100 can be provided with two connectors, namely a second connector 102 and a third connector 103. Through the second connector 102, the detection module can be connected to the previous detection module, and through the third connector 103, the detection module can be connected to the next detection module.

[0106] For example, the second connector of the second detection module connects to the third connector of the third detection module to establish a connection between the second and third detection modules. The third connector of the second detection module connects to the second connector of the first detection module to establish a connection between the second and first detection modules. The third connector of the first detection module connects to other components in the BMS. The second connector of the third detection module is used for expansion of the detection module.

[0107] In one specific embodiment, each detection module is provided on a slave circuit board, and a controller, a voltage converter, etc. are provided on a master circuit board. The second connector of slave circuit board 2 is connected to the third connector of slave circuit board 3 to achieve a connection between slave circuit boards 2 and 3. The third connector of slave circuit board 2 is connected to the second connector of slave circuit board 1 to achieve a connection between slave circuit boards 2 and 1. The third connector of slave circuit board 1 is connected to the master circuit board.

[0108] The second connector and the third connector can be connected by a connecting line. When the detection module needs to be expanded, for example, a fourth detection module needs to be added, the third connector of the fourth detection module can be directly connected to the second connector of the third detection module to realize the connection between the fourth detection module and the third detection module.

[0109] In other embodiments, please refer to Figure 6, each detection module 100 can also be provided with a fourth connector 104, and a fifth connector (not shown) can be provided on the corresponding battery cell 2000. By connecting the fourth connector 104 and the fifth connector, the connection between the detection module 100 and the corresponding battery cell 2000 can be achieved.

[0110] When the battery module needs to be expanded, the fourth connector of the newly added fourth detection module can be directly connected to the fifth connector of the newly added battery unit, and the third connector of the fourth detection module can be connected to the second connector of the third detection module to achieve the expansion of the fourth detection module.

[0111] It should be noted that the above expansion methods for detection modules are merely examples. The newly added (N+1) detection module can be directly connected to the (N) detection module via a connector. In addition, the newly added (N+1) detection module can be inserted between any adjacent detection modules, for example, between the second detection module and the first detection module. Specifically, the connection between the second detection module and the first detection module can be disconnected first, and then the (N+1) detection module and the second detection module, as well as the (N+1) detection module and the first detection module, can be connected separately via connectors.

[0112] In some embodiments, the detection module 100 is configured to sample the voltage and / or temperature of the battery cell and determine whether the voltage and / or temperature are abnormal when the BMS is in sleep mode. It can also send a first signal when a voltage or temperature abnormality is determined, and send a first signal when the first signal is received. The detection module 100 may include a detection chip that integrates the above functions.

[0113] Furthermore, in some embodiments, the detection chip can also be configured to transmit fault information when a battery cell abnormality is detected when the BMS is in working mode. That is, when the BMS is in working mode, when a detection module detects a battery cell abnormality, the detection chip has the ability to send fault information to the next detection module, where the battery cell abnormality here includes temperature abnormality and / or voltage abnormality, and the fault information includes the identity of the abnormal battery cell and the type of abnormality (voltage abnormality and / or temperature abnormality).

[0114] In other embodiments, the BMS may further include at least two current detection modules, each of which is electrically connected to a battery cell. The current detection module may be configured to have the function of detecting current when the BMS is in working mode and determining whether the current is abnormal. Also, when an abnormal current of a battery cell is detected, the function of transmitting fault information to the controller 400. The fault information here may include, for example, the identity of the abnormal battery cell, the type of abnormality (current abnormality), etc.

[0115] Specifically, the current detection module can directly transmit the fault information to the controller 400, or a slave controller can be set up, which is electrically connected to the current detection module and the controller 400 respectively. The current detection module first sends the fault information to the slave controller, and the slave controller collects the fault information of each current detection module and then sends it to the main controller.

[0116] In a specific implementation, the current detection module and the slave controller may be provided on a main circuit board or on another circuit board.

[0117] In some other embodiments, the detection module is configured to include a sampling circuit and a detection unit, and the second detection module to the Nth detection module are further configured to include a signal transmission circuit.

[0118] Referring to Figure 7 , the detection units (121, 122, 123) are electrically connected to the sampling circuit 110, which acquires the voltage signal and / or temperature signal of the corresponding battery cell through the sampling circuit. The detection units include first connection terminals (FAULT_IO_1, FAULT_IO_2, ..., FAULT_IO_N) and second connection terminals (FAULT_1, FAULT_2, ..., FAULT_N). The signal transmission circuit 130 between two adjacent detection units is electrically connected to the second connection terminal of one detection unit and to the first connection terminal of the other detection unit.

[0119] For example, the signal transmission circuit 130 of the second detection module is electrically connected to the second connection terminal FAULT_2 of the second detection unit 122 , and is electrically connected to the first connection terminal FAULT_IO_1 of the first detection unit 121 .

[0120] FIG8 shows another structure of a detection module. In the embodiment shown in FIG8 , the detection module further includes a communication circuit 140 . The communication circuit 140 is electrically connected between adjacent detection units. The communication circuit of the first detection module is also electrically connected to the controller 400 . FIG7 and FIG8 are both described using three detection modules as an example.

[0121] The sampling circuit is configured to collect voltage signals and / or temperature signals of corresponding battery cells. In practical applications, the sampling circuit may also employ a circuit having a battery voltage and / or temperature sampling function. The sampling circuit may be a circuit or device capable of collecting the temperature and voltage of a battery cell. For example, the sampling circuit may include an NTC thermistor and a voltage divider resistor.

[0122] The detection unit is configured to send a first signal when the voltage signal and / or temperature signal is detected to be abnormal when the BMS is in sleep mode, and to send a first signal when the first signal is received. In other embodiments, the detection unit may also be configured to send the fault information via the communication circuit when it is determined that the temperature and / or voltage of the corresponding battery cell is abnormal when the BMS is in working mode, and to send the fault information via the communication circuit when the fault information sent by the communication circuit of the previous detection module is received.

[0123] In a specific implementation, the detection unit may use components with the above functions, such as an analog front end (AFE) chip.

[0124] As an application example, taking the first detection unit as an example, when the BMS is in sleep mode, the first detection unit obtains the voltage and / or temperature of battery cell 1 through the sampling circuit and determines whether a voltage abnormality and / or temperature abnormality occurs. When a voltage abnormality and / or temperature abnormality occurs, the first detection unit sends a first signal through the second connection terminal FAULT_1. When the first connection terminal FAULT_IO_1 receives the first signal, the first detection unit sends the first signal through the second connection terminal FAULT_1.

[0125] In sleep mode, the detection unit may only have a simple comparison function to reduce power consumption. Specifically, the sampled temperature value may be compared with a temperature threshold. If the temperature value is less than the minimum temperature threshold, it is determined that the battery cell is in a low-temperature environment or the battery cell itself is too cold. If the temperature value is greater than the maximum temperature threshold, it is determined that the battery cell is in a high-temperature environment or the battery cell itself is too hot.

[0126] The sampled voltage value may also be compared with a voltage threshold. If the voltage value is greater than a maximum voltage threshold, it is determined that the voltage of the battery cell is too high. If the voltage value is less than a minimum voltage threshold, it is determined that the voltage of the battery cell is too low.

[0127] The minimum temperature threshold, maximum temperature threshold, minimum voltage threshold and maximum voltage threshold can be set based on the specific application situation. Generally speaking, it depends on the low temperature resistance, high temperature resistance, low voltage resistance and high voltage resistance of the battery cell. This application does not specifically limit the temperature threshold and voltage threshold of the battery cell.

[0128] For example, the maximum temperature threshold is 65°C, the minimum temperature threshold is -20°C, -10°C, etc., the minimum voltage threshold is 2.7V, and the maximum voltage threshold is 3.65V. That is, when the battery cell temperature exceeds 65°C, the battery cell is determined to be overheated, when it is below -20°C, the battery cell is determined to be underheated, when the battery cell voltage exceeds 3.65V, the battery cell is determined to be overvoltage, and when it is below 2.7V, the battery cell is determined to be undervoltage.

[0129] The above temperature values ​​and voltage values ​​are shown only as examples and are not intended to limit the temperature thresholds and voltage thresholds of the present application.

[0130] When the BMS is in working mode (when the BMS is in working mode, the detection unit is also in working mode), the detection unit obtains the voltage and / or temperature of the corresponding battery cell through the sampling circuit, and determines whether voltage abnormality and / or temperature abnormality occurs. When an abnormality occurs, fault information is sent through the communication circuit.

[0131] In some embodiments, the detection unit further includes a third connection terminal. Specifically, the third connection terminal can output a high-level voltage signal to power signal transmission circuits, etc. In one specific implementation, the voltage at the third connection terminal can be between 3 and 5V. In one specific implementation, the detection unit can be configured to draw power from the corresponding battery cell and perform voltage conversion to generate the high-level voltage signal. For the third connection terminal, please refer to CVDD_N and CVDD_N-1 in Figure 9.

[0132] In a specific implementation, the physical forms of the first connection end, the second connection end, and the third connection end may be pins or connection terminals on the AFE chip.

[0133] The signal transmission circuit is configured to transmit the first signal between adjacent detection units and can be a circuit with a signal transmission function. In some embodiments, to improve circuit safety, the signal transmission circuit is a signal transmission circuit with an isolation function.

[0134] Specifically, in one embodiment, the signal transmission circuit may include a first switch and a first isolation element. The first isolation element includes an input terminal and an output terminal. The first terminal of the first switch is electrically connected to the third connection terminal of the Mth detection unit, the second terminal is electrically connected to the input terminal of the first isolation element, and the third terminal is electrically connected to the second connection terminal of the Mth detection unit. The input terminal of the first isolation element is also electrically connected to the Mth reference ground.

[0135] The output end of the first isolation element is electrically connected to the first connection end and the third connection end of the M-1th detection unit respectively, and the output end is also electrically connected to the M-1th reference ground, where M is a positive integer from 2 to N.

[0136] It will be understood that each detection unit has its own corresponding reference ground. For example, the Mth detection unit corresponds to the Mth reference ground, and the M-1th detection unit corresponds to the M-1th reference ground. Each detection module uses its own corresponding reference ground. The voltage of the Mth reference ground of the Mth detection unit relative to the third connection terminal CVDD_M of the Mth detection unit is 0V, and the voltage of the M-1th reference ground of the M-1th detection unit relative to the third connection terminal CVDD_M of the M-1th detection unit is 0V.

[0137] The first switch can be a controllable switch configured to perform a conduction operation when the second connection terminal of the Mth detection unit sends a first signal, thereby conducting between the third connection terminal CVDD_M of the Mth detection unit and the input terminal of the first isolation element to provide a drive signal to the input terminal of the first isolation element. The first switch can be a transistor, a field-effect transistor, a signal relay, an insulated gate bipolar transistor (IGBT), etc.

[0138] The first isolation element may be a switch element with an isolation function, configured to perform a conduction operation when the input terminal receives a driving signal. The first isolation element may be a photocoupler, a photofield effect transistor, or a thyristor photocoupler.

[0139] FIG9 illustrates a signal transmission circuit 130 corresponding to the Nth detection module, using a transistor as the first switch and a photocoupler as the first isolation element as an example. As shown in FIG9 , the first switch Q1 has a first end electrically connected to the third connection terminal CVDD_N of the Nth detection unit, a second end electrically connected to the first end of the first isolation element U1, and a third end electrically connected to the second connection terminal FAULT_N of the Nth detection unit. The second end of the first isolation element U1 is electrically connected to the Nth reference ground. The input end of the first isolation element U1 includes the first end and the second end of the first isolation element U1.

[0140] The third end of the first isolation element U1 is electrically connected to the third connection end and the first connection end of the N-1th detection unit respectively, and the fourth end is electrically connected to the N-1th reference ground. The output end of the first isolation element U1 includes the third end and the fourth end of the first isolation element U1.

[0141] When the first switch is a transistor, the first end of the first switch is an emitter, the second end is a collector, and the third end is a base.

[0142] Taking a low-level first signal as an example, the operation of the signal transmission circuit is described. When the second connection terminal FAULT_N of the Nth detection unit sends the first signal, the first switch Q1 turns on, and the first terminal of the first isolation element U1 is electrically connected to the third connection terminal of the Nth detection unit. The voltage between the high-level voltage signal provided by the third connection terminal and the Nth reference ground reaches the turn-on voltage of the light-emitting diode in the first isolation element U1. The light-emitting diode turns on, and the transistor in the first isolation element U1 turns on, and the third and fourth terminals of the first isolation element U1 are connected.

[0143] Since the third terminal of the first isolation element U1 is connected to the N-1th reference ground, the voltage of the third terminal is pulled low, and the third terminal outputs a low-level signal. Prior to this, since the third terminal is pulled high by the voltage output by the third connection terminal of the N-1th detection unit, the third terminal outputs a high-level signal.

[0144] The low-level signal outputted from the third terminal of the first isolation element U1 is transmitted to the first connection terminal FAULT_IO_N-1 of the (N-1)th detection unit, thereby achieving the transmission of the low-level signal (ie, the first signal).

[0145] In some other embodiments, referring to Figure 9 , the signal transmission circuit 130 may further include a plurality of resistors. As shown in Figure 9 , the signal transmission circuit 130 includes a first resistor R1 , a second resistor R2 , a third resistor R3 , and a fourth resistor R4 .

[0146] The first end of the first resistor R1 is electrically connected to the third connection terminal CVDD_N of the Nth detection unit, and the second end is electrically connected to the third end of the first switch Q1. The first end of the second resistor R2 is electrically connected to the second connection terminal FAULT_N of the Nth detection unit, and the second end is electrically connected to the second end of the first resistor R1 and the third end of the first switch Q1.

[0147] A first end of the third resistor R3 is electrically connected to the third connection terminal CVDD_N-1 of the (N-1)th detection unit, and a second end is electrically connected to the third end of the first isolation element. A first end of the fourth resistor R4 is electrically connected to the second end of the third resistor R3 and the third end of the first isolation element, respectively, and a second end is electrically connected to the first connection terminal FAULT_IO_N-1 of the (N-1)th detection unit.

[0148] The communication circuit may be any suitable circuit having a communication function, such as a daisy chain communication circuit, a CAN communication circuit, a 485 communication circuit, etc.

[0149] The voltage converter can be a voltage converter with a step-down function. In situations where the total battery voltage provided by the power module composed of battery cells is relatively high, for example, around 400 to 500 volts or even higher, the voltage converter can include a transformer and a DC-DC converter. The transformer first steps down the total battery voltage to a lower voltage (e.g., 12V), and the DC-DC converter then converts the lower voltage to the voltage required by the various components in the BMS (e.g., 5V, 3.3V, etc.).

[0150] FIG10 shows the structure of the voltage converter 300 in this embodiment. The voltage converter 300 includes a transformer 301 and a DC-DC converter 302. The transformer 301 is electrically connected to the switching circuit 200, and the DC-DC converter 302 is electrically connected to the controller 400 to provide a supply voltage for the controller 400. The DC-DC converter 302 can also be electrically connected to other components in the BMS to provide a supply voltage for these components.

[0151] In the case where the total voltage of the battery of the power module composed of the battery cells is low, the voltage converter may only include a DCDC converter to convert the voltage provided by the battery cells into the voltage required by each device in the BMS.

[0152] The switch circuit can perform a conduction operation in response to the first signal. In some embodiments, referring to Figures 11 and 12, to improve safety and achieve isolation between strong and weak currents, the switch circuit can include a second switch 210, a second isolation element 220, an energy storage element 230, and a third isolation element 240.

[0153] 11 , due to the provision of the second isolation element 220 and the third isolation element 240 , the BMS system is divided into a low-voltage area and a high-voltage area, achieving isolation between high and low voltages and improving the safety of the BMS.

[0154] The first end of the second switch 210 is electrically connected to the third connection terminal CVDD1 of the first detection unit 121, the second end is electrically connected to the input terminal of the second isolation element 220, and the third end is electrically connected to the second connection terminal FAULT_1 of the first detection unit 121. The output end of the second isolation element 220 is electrically connected to the first end of the energy storage element 230 and the input end of the third isolation element 240. The second end of the energy storage element is grounded, and the output end of the third isolation element 240 is electrically connected to the voltage converter 300.

[0155] The second switch 210 can be a controllable switch configured to perform a conduction operation upon receiving a first signal transmitted from the second connection terminal FAUT_1 of the first detection unit, thereby conducting a connection between the third connection terminal CVDD1 of the first detection unit and the input terminal of the second isolation element 220, thereby providing a drive signal to the input terminal of the second isolation element 220. The second switch can be a transistor, a field-effect transistor, a signal relay, an insulated gate bipolar transistor (IGBT), or the like.

[0156] The second isolation element 220 may be a switching element with an isolation function. Upon receiving a driving signal at its input terminal, the second isolation element 220 is configured to conduct electricity, connecting the energy storage element 230 to the input terminal of the third isolation element 240, thereby providing a driving signal to the input terminal of the third isolation element. The second isolation element may be a photocoupler, a photofield-effect transistor, or a thyristor photocoupler.

[0157] The third isolation element 240 can be a switching element with an isolation function. It is configured to conduct when a drive signal is received at its input terminal, thereby establishing a connection between the external power supply and the voltage converter. The third isolation element can be a thyristor photocoupler. When the total battery voltage provided by each battery cell is high, a spike current may be generated when the voltage converter is powered on. Thyristor photocouplers have a strong ability to withstand transient high currents, preventing damage to the third isolation element and potentially affecting the stability of the BMS during such spikes.

[0158] In addition to the thyristor photocoupler, the third isolation element may also be other switching elements with isolation function, such as a photocoupler, a photoelectric field effect transistor, etc.

[0159] The energy storage element may be an element capable of storing electrical energy, such as a capacitor. In some embodiments, to increase the standby time of the BMS, the energy storage element may be a supercapacitor, for example, with a capacity of 1.5F, 3.5F, or 5.5F.

[0160] FIG12 exemplarily shows a structure of a switch circuit. In the embodiment shown in FIG12 , the second switch 210 is a transistor Q2 , the second isolation element is a photocoupler U2 , and the third isolation element is a thyristor photocoupler U3 .

[0161] The first end of the second switch 210 is electrically connected to the third connection terminal CVDD1 of the first detection unit 121, the second end is electrically connected to the first end of the second isolation element 220, and the third end is electrically connected to the second connection terminal FAULT_1 of the first detection unit 121. The second end of the second isolation element 220 is electrically connected to the first reference ground, the third end is electrically connected to the first end of the energy storage element 230, and the fourth end is electrically connected to the first end of the third isolation element 240. The second end of the energy storage element is grounded. The input end of the second isolation element 220 includes the first and second ends of the second isolation element 220, and the output end of the second isolation element 220 includes the third and fourth ends of the second isolation element 220.

[0162] A second terminal of the third isolation element 240 is grounded, a third terminal is electrically connected to an external power source, and a fourth terminal is electrically connected to the voltage converter 300 .

[0163] When the second switch is a transistor, the first end of the second switch is an emitter, the second end is a collector, and the third end is a base.

[0164] In some other embodiments, referring to FIG12 , the switch circuit 200 may further include a plurality of resistors. As shown in FIG12 , the switch circuit 200 includes a fifth resistor R5 and a sixth resistor R6.

[0165] A first end of the fifth resistor R5 is electrically connected to the third connection terminal CVDD1 of the first detection unit, and a second end is electrically connected to the third end of the second switch 210. A first end of the sixth resistor R6 is electrically connected to the second connection terminal FAULT_1 of the first detection unit, and a second end is electrically connected to the second end of the fifth resistor R5 and the third end of the second switch 210, respectively.

[0166] The operation of the switch circuit 200 is described using the embodiment shown in FIG12 as an example. When the second connection terminal FAULT_1 of the first detection unit sends a first signal, the second switch 210 turns on, and the first terminal of the second isolation element 220 is electrically connected to the third connection terminal CVDD1 of the first detection unit. The voltage between the high-level voltage signal provided by the third connection terminal and the first reference ground reaches the turn-on voltage of the light-emitting diode of the second isolation element 220. When the light-emitting diode turns on, the transistor in the second isolation element 220 turns on, and the third and fourth terminals of the second isolation element 220 are connected.

[0167] The first end of the third isolation element is electrically connected to one end of the energy storage element 230. The voltage between the voltage signal provided by the energy storage element 230 and the ground reaches the turn-on voltage of the light-emitting diode of the third isolation element. When the light-emitting diode is turned on, the thyristor of the third isolation element 240 is turned on, and the voltage converter 300 is electrically connected to the external power supply (in this embodiment, electrically connected to the positive electrode B+ of the battery).

[0168] In an embodiment of the present application, when the BMS is in sleep mode, the electric energy provided by the energy storage element (such as a supercapacitor) is used to drive the third isolation element to turn on the external power supply and the voltage converter, so that the voltage converter converts the voltage provided by the external power supply to power the BMS and wake up the BMS.

[0169] In other embodiments, a standby power supply can be used to power the third isolation element. This standby power supply can draw power from a battery cell and perform voltage conversion to provide the voltage required by the third isolation element. Alternatively, an external battery can be used. Relatively speaking, energy storage elements consume less power than standby power supplies and are less expensive than external batteries.

[0170] In some embodiments, to prevent the energy storage element from depleting, the third isolation element cannot be turned on, thereby preventing the BMS from waking up. The BMS also includes a charging circuit for charging the energy storage element. Referring to Figures 7, 8, and 11, the charging circuit 250 is connected to the voltage converter 300 and the energy storage element 230, respectively. When the voltage converter 300 establishes a path to the external power source, the voltage converter 300 charges the energy storage element 230 through the charging circuit 250.

[0171] In one specific embodiment, for example, when the energy storage system is in its shelf life or shipping period, the energy storage system may not be used for a long period of time. If there is no abnormality in the battery cells, the voltage converter 300 cannot be connected to the external power supply to charge the energy storage element, and the energy storage element is at risk of running out of power. To avoid this situation, in some embodiments, referring to Figures 7, 8, and 11, the BMS further includes a first charging port 2301 and / or a second charging port 2302. The first charging port is configured to connect to a USB data cable to charge the energy storage element, and the second charging port is configured to connect to an energy storage converter to charge the energy storage element.

[0172] The first charging port can be connected to a charger with a USB data cable to draw power from the municipal power supply system or other backup batteries to charge the energy storage element. The second charging port can also be connected to an energy storage converter to charge the energy storage element using external device 4000 in Figure 2. Providing multiple charging methods ensures that the energy storage element has power, ensuring the BMS fault wake-up function is implemented.

[0173] In some embodiments, referring to FIG. 13 , the BMS further includes a seventh resistor R7 , a first end of the seventh resistor R7 being electrically connected to the fourth end of the third isolation element 240 , and a second end of the seventh resistor R7 being electrically connected to the voltage converter 300 .

[0174] When the third isolation element 240 employs a switching element with signal isolation functionality, such as a thyristor optocoupler, it is possible that the third isolation element 240 cannot be turned off. In some embodiments, to ensure reliable shutdown of the third isolation element 240, the BMS further includes a third switch Q3. The third switch Q3 is electrically connected to the controller 400 and the voltage converter, respectively, and is configured to perform a turn-on or turn-off operation in response to a control signal from the controller.

[0175] FIG13 illustrates a structural form of the third switch Q3. In the embodiment shown in FIG13 , the third switch Q3 is electrically connected between the external power supply and the voltage converter 300, providing another conduction path between the external power supply and the voltage converter 300. Its function is to reliably shut down the third isolation element 240.

[0176] Taking a thyristor (SCR) optocoupler as an example, the SCR optocoupler is considered reliably shut down only when both its primary and secondary sides are off. SCR optocouplers are primarily used in alternating current (AC). When used in AC, they shut down by detecting the AC's zero-crossing point and shutting off the light-emitting diode (LED) at that point, thereby reliably shutting down the SCR optocoupler. The AC's zero-crossing point is the moment when the AC voltage or current reaches "zero." At this point, the AC voltage or current is 0 or near 0, for example, less than 30V.

[0177] Thyristor optocouplers are difficult to shut down in direct current. To ensure that the third isolation element has both the ability to withstand large transient currents and reliable shutdown, this embodiment of the present application also includes a third switch Q3. This reliable shutdown mechanism works by connecting the voltage converter 300 to the external power supply after the thyristor optocoupler is turned on, providing a supply voltage to the controller 400, waking the BMS. The controller 400 then sends a control signal to the third switch Q3, turning it on.

[0178] Due to the current limiting effect of the seventh resistor R7, current selectively flows from the third switch Q3 to the voltage converter 300, thereby reducing the current flowing through the thyristor to zero. After the secondary side current of the thyristor optocoupler drops to zero, the primary side light-emitting diode can be turned off at any time, thereby reliably shutting down the thyristor optocoupler.

[0179] The third switch may be a controllable switch, such as a field effect transistor. In addition, it may also be other switch elements, such as a triode, a field effect transistor, a signal relay, an insulated gate bipolar transistor (IGBT), etc.

[0180] Specifically, in some embodiments, the third switch Q3 can be driven to conduct by a driving circuit. Referring to FIG. 13 , the BMS further includes a driving circuit 250 electrically connected to the third switch Q3 and the controller 400 , respectively, for receiving a control signal from the controller 400 and generating a driving signal to drive the third switch Q3 to conduct or shut down.

[0181] The following uses Figure 7 as an example to illustrate the specific structural form of the detection module in practical applications, to facilitate its expansion. Referring also to Figure 14 , slave circuit board 1 can be equipped with a sampling circuit, a detection unit, a communication circuit 140, a second switch 210, and a second isolation element 220. Slave circuit boards other than slave circuit board 1 can also be equipped with a detection unit, a sampling circuit 110, a communication circuit 140, and a signal transmission circuit 130.

[0182] Each slave circuit board is provided with a second connector 102, a third connector 103, and a fourth connector 104. In slave circuit board 1, one end of sampling circuit 110 is electrically connected to fourth connector 104, and the other end is electrically connected to first detection unit 121. First detection unit 121 has a first connection terminal FAULT_IO_1 electrically connected to second connector 102, and a second connection terminal FAULT_1 electrically connected to second switch 210. Second switch 210 is also electrically connected to one end of second isolation element 220, the other end of which is electrically connected to third connector 103. First detection unit 121 is also electrically connected to one end of communication circuit 140, the other end of which is electrically connected to third connector 103.

[0183] In slave circuit boards other than slave circuit board 1, such as slave circuit board 2, one end of sampling circuit 110 is electrically connected to fourth connector 104, and the other end is electrically connected to second detection unit 122. Second detection unit 122 has a first connection end FAULT_IO_2 electrically connected to second connector 102, a second connection end FAULT_2 electrically connected to one end of signal transmission circuit 130, and the other end of signal transmission circuit 130 electrically connected to third connector 103. Second detection unit 122 is also electrically connected to one end of communication circuit 140, and the other end of communication circuit 140 is electrically connected to third connector 103.

[0184] The fourth connector 104 of each slave circuit board can be used to electrically connect each slave circuit board to the battery unit. The second connector 102 and the third connector 103 of each slave circuit board can be used to connect the slave circuit boards. The third connector 103 of the slave circuit board 1 is used to connect to the main circuit board.

[0185] When the detection module needs to be expanded, for example, a slave circuit board 4 needs to be added, the third connector of the slave circuit board 4 and the second connector 102 of the slave circuit board 3 can be directly connected with a connecting cable to realize the connection between the slave circuit board 4 and the slave circuit board 3.

[0186] The working principle of an embodiment of the BMS of the present application is described below using FIG. 8 as an example.

[0187] When the third isolation element 240 is turned on, the voltage converter 300 is electrically connected to B+, and the voltage converter 300 provides a power supply voltage to the controller 400 based on B+, and the BMS is in the working mode.

[0188] When the third isolation element 240 is turned off, the connection between the voltage converter 300 and B+ is disconnected, the voltage converter 300 does not provide a supply voltage, and the BMS is in a sleep mode.

[0189] When the BMS is in operating mode, the detection unit acquires the battery cell voltage and / or temperature collected by the sampling circuit and determines whether there are any voltage and / or temperature anomalies. If an anomaly is found, the detection unit sends fault information to the communication circuit. The communication circuit then transmits the information to the next detection unit, and finally to the controller 400. The controller 400 uses this fault information to identify the faulty battery cell and take appropriate protective measures.

[0190] When the BMS is in sleep mode, the detection unit obtains the voltage and / or temperature of the battery cell collected by the sampling circuit, and confirms whether there is a voltage abnormality and / or temperature abnormality. When an abnormality exists, the FAULT_N sent by the detection unit outputs a low-level signal (this embodiment is illustrated by taking the first signal as a low-level signal as an example).

[0191] Assume that the third detection unit 123 detects that the corresponding battery cell 3 is abnormal, the third detection unit 123 sets its second connection terminal FAULT_3 to low, and FAULT_3 sends a low level signal to the signal transmission circuit 130 .

[0192] Please refer to Figure 9 as well. Assuming N=3, Figure 9 shows the signal transmission circuit of the third detection module. After the signal transmission circuit 130 receives the low-level signal through FAULT_3, the first switch Q1 is turned on. The first end of the first isolation element is then electrically connected to the third connection end of the third detection unit. The voltage difference between the voltage provided by the third connection end and the third reference ground reaches the turn-on voltage of the light-emitting diode of the first isolation element U1. When the light-emitting diode is turned on, the transistor is turned on. The third end of the first isolation element is electrically connected to the second reference ground, and the third end of the first isolation element is set low, sending a low-level signal to the first connection end FAULT_IO_2 of the second detection unit.

[0193] When the second detection unit 122 receives a low level signal at the first connection terminal FAULT_IO_2 , the second detection unit 122 converts the level signal at the second connection terminal FAULT_2 from a high level signal to a low level signal.

[0194] Based on the same principle, the signal transmission circuit 130 transmits a low-level signal to the first connection terminal FAULT_IO_1 of the first detection unit 121. When the first detection unit 121 receives the low-level signal at the first connection terminal FAULT_IO_1, it sets the level signal of the second connection terminal FAULT_1 to low, and FAULT_1 sends a low-level signal to the second switch 210.

[0195] Please also refer to Figure 12. After the second switch 210 receives a low-level signal through FAULT_1, the second switch 210 is turned on, and the first end of the second isolation element is electrically connected to the third connection terminal CVDD1 of the first detection unit. When the voltage difference between the voltage provided by CVDD1 and the first reference ground reaches the turn-on voltage of the light-emitting diode of the second isolation element 220, the light-emitting diode of the second isolation element 220 is turned on, and the transistor is turned on.

[0196] The third and fourth terminals of the second isolation element are electrically conductive, and the first terminal of the third isolation element is electrically connected to supercapacitor 230. When the voltage difference between supercapacitor 230 and ground reaches the turn-on voltage of the light-emitting diode of third isolation element 240, the diode and the thyristor are turned on. Voltage converter 300 is electrically connected to B+.

[0197] Please refer to FIG. 8 again. After the voltage converter 300 forms a path with the B+ of the battery module, it starts to convert the voltage and provides the power supply voltage to the controller 400. The BMS is awakened.

[0198] Each detection unit obtains the voltage and / or temperature of the battery cell collected by the sampling circuit, and determines whether there is an abnormality in the battery cell based on the collected voltage and / or temperature.

[0199] As described above, battery cell 3 is an abnormal battery cell. At this point, the third detection unit 123 detects the abnormality and sends a fault message. This fault message is transmitted to the second detection unit 122 via the communication circuit 140. The second detection unit 122 sends this fault message to its corresponding communication circuit, which in turn transmits this fault message to the first detection unit 121. The first detection unit 121 then transmits this fault message to the controller 400 via the communication circuit.

[0200] By analyzing the fault information, the controller 400 can determine the faulty battery unit and take protective measures.

[0201] After the voltage converter 300 starts working, it charges the energy storage element 230 through the charging circuit 250 to ensure that the energy storage element 230 has sufficient power.

[0202] Referring to FIG. 13 again, after the controller 400 is powered on, it sends a control signal to the driving circuit 250 , so that the driving circuit 250 drives the third switch Q3 to turn on, thereby turning off the secondary side device of the third isolation element 240 .

[0203] After the fault is cleared, the detection unit may send a second signal (eg, a high-level signal) to turn off the primary-side device of the third isolation element 240 , thereby achieving reliable shutdown of the third isolation element.

[0204] The above description is merely an embodiment of the present application and does not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

[0205] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Based on the concept of the present application, the technical features in the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations in different aspects of the present application as described above. For the sake of simplicity, they are not provided in detail. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A battery management system, characterized in that: include: N detection modules, wherein the first detection module to the Nth detection module are electrically connected in sequence, each of the detection modules is configured to be electrically connected to a battery cell, and the first detection module is configured to output a first signal when any battery cell has an abnormality when the battery management system is in a sleep mode, wherein N is a positive integer ≥ 2, and the abnormality includes abnormal temperature and / or abnormal voltage of the battery cell; a switch circuit, electrically connected to the first detection module and configured to be turned on in response to the first detection module outputting the first signal; A voltage converter and a controller, wherein the voltage converter is electrically connected to the switching circuit and the controller respectively, and the voltage converter is configured to step down the voltage output by the external power supply based on the conduction of the switching circuit and then output the voltage, and the output voltage powers the controller to wake up the battery management system.

2. The battery management system according to claim 1, characterized in that: The N-1th detection module is configured as follows: When the battery management system is in a sleep mode, it sends a first signal when detecting an abnormality in a corresponding battery cell, and sends a first signal after receiving the first signal sent by an adjacent Nth detection module.

3. The battery management system according to claim 1 or 2, characterized in that: Each of the detection modules includes a first connector, and adjacent detection modules can be electrically connected through the first connector. The Nth detection module is configured to be electrically connected to the N+1th detection module through the first connector.

4. The battery management system according to claim 1 or 2, characterized in that: Each of the detection modules includes a second connector and a third connector. The detection module can be electrically connected to the previous detection module through the second connector, and to the next detection module through the third connector. The Nth detection module is configured to be electrically connected to the N+1th detection module through the second connector.

5. The battery management system according to claim 2, characterized in that: Each of the detection modules includes a sampling circuit and a detection unit; The detection unit includes a first connection terminal and a second connection terminal, and is electrically connected to the sampling circuit, and obtains the voltage signal and / or temperature signal of the battery cell through the sampling circuit; Any detection module from the second detection module to the Nth detection module also includes: a signal transmission circuit, each of the signal transmission circuits is electrically connected to the second connection end of the Mth detection unit and electrically connected to the first connection end of the M-1th detection unit, and is used to transmit the first signal between adjacent detection units, where M is a positive integer from 2 to N.

6. The battery management system according to claim 5, characterized in that: Each of the detection units further includes a third connection end; The signal transfer circuit includes a first switch and a first isolation element, wherein the first isolation element includes an input terminal and an output terminal; a first end of the first switch electrically connected to the third connection end of the Mth detection unit, a second end of the first switch electrically connected to the input end of the first isolation element, a third end of the first switch electrically connected to the second connection end of the Mth detection unit, and the input end of the first isolation element is further electrically connected to the Mth reference ground; The output end of the first isolation element is electrically connected to the first connection end and the third connection end of the M-1th detection unit respectively, and the output end of the first isolation element is also electrically connected to the M-1th reference ground.

7. The battery management system according to claim 6, characterized in that: The signal transmission circuit further includes: a first resistor, wherein a first end of the first resistor is electrically connected to the third connection end of the Mth detection unit, and a second end of the first resistor is electrically connected to the third end of the first switch; a second resistor, wherein a first end of the second resistor is electrically connected to the second connection end of the Mth detection unit, and a second end of the second resistor is electrically connected to the second end of the first resistor and the third end of the first switch; a third resistor, wherein a first end of the third resistor is electrically connected to the third connection end of the (M-1)th detection unit, and a second end of the third resistor is electrically connected to the output end of the first isolation element; a fourth resistor, wherein a first end of the fourth resistor is electrically connected to the second end of the third resistor and the output end of the first isolation element respectively, and a second end of the fourth resistor is electrically connected to the first connection end of the M-1 detection unit.

8. The battery management system according to claim 6 or 7, characterized in that: The third connection terminal is used to output a voltage signal. The first switch is configured to be turned on in response to the second connection terminal of the detection unit generating the first signal based on the voltage signal output by the third connection terminal.

9. The battery management system according to claim 6 or 7, characterized in that: The switch circuit includes: a second switch, a second isolation element, a third isolation element and an energy storage element, wherein the second isolation element and the third isolation element each include an input end and an output end; a first end of the second switch electrically connected to the third connection end of the first detection unit, a second end of the second switch electrically connected to the input end of the second isolation element, the input end of the second isolation element also being electrically connected to the first reference ground, and a third end of the second switch electrically connected to the second connection end of the first detection unit; The output end of the second isolation element is electrically connected to the first end of the energy storage element and the input end of the third isolation element respectively, the second end of the energy storage element is grounded, and the input end of the third isolation element is also connected to the ground; An output terminal of the third isolation element is electrically connected to the voltage converter.

10. The battery management system according to claim 9, characterized in that: The switching circuit further includes: a fifth resistor, wherein a first end of the fifth resistor is electrically connected to the third connection end of the first detection unit, and a second end of the fifth resistor is electrically connected to the third end of the second switch; a sixth resistor, wherein a first end of the sixth resistor is electrically connected to the second connection end of the first detection unit, and a second end of the sixth resistor is electrically connected to the second end of the fifth resistor and the third end of the second switch respectively.

11. The battery management system according to claim 9, characterized in that: The energy storage element includes a supercapacitor.

12. The battery management system according to claim 9, characterized in that: The first switch and the second switch respectively include at least one of a triode or a field effect transistor, the first isolation element and the second isolation element respectively include at least one of a photocoupler, a photofield effect transistor or a thyristor photocoupler, and the third isolation element includes a thyristor photocoupler. 13 . The battery management system according to claim 9 , further comprising a seventh resistor, wherein a first end of the seventh resistor is electrically connected to the output end of the third isolation element, and a second end of the seventh resistor is electrically connected to the voltage converter. 14 . The battery management system according to claim 13 , further comprising a third switch electrically connected to the controller and the voltage converter, respectively, and configured to be turned on or off in response to a control signal from the controller.

15. The battery management system according to claim 14 further comprises a drive circuit, wherein the drive circuit is electrically connected to the third switch and the controller respectively, and is used to receive a control signal from the controller to generate a drive signal, and the third switch can be turned on or off in response to the drive signal. 16 . The battery management system according to claim 9 , further comprising a charging circuit, wherein the charging circuit is electrically connected to the energy storage element and the voltage converter, respectively, and is configured to charge the energy storage element.

17. The battery management system according to claim 16, further comprising a first charging port and / or a second charging port; in, The first charging port is configured to be connected to a USB data cable to charge the energy storage element, and the second charging port is configured to be connected to an energy storage converter to charge the energy storage element.

18. The battery management system according to claim 1, characterized in that: The voltage converter includes a DCDC converter and a transformer; or, The voltage converter includes a DCDC converter.

19. The battery management system according to claim 1, characterized in that: The detection module further includes a communication circuit, which is electrically connected between adjacent detection modules, and the communication circuit is electrically connected between the first detection module and the controller.

20. The battery management system according to claim 19, characterized in that: The communication circuit includes at least one of a daisy chain communication circuit, a CAN communication circuit and a 485 communication circuit.

21. An energy storage system, characterized in that: The invention comprises N battery units and a battery management system as claimed in any one of claims 1 to 20, wherein each of the battery units comprises a plurality of battery cells.

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