Battery management system, battery pack and electric equipment

Abstract

The invention provides a battery management system, a battery pack and electric equipment. The battery management system comprises a high voltage interlock circuit used for being electrically connected with a voltage source and receiving output voltage of the voltage source, and the high voltage interlock circuit is configured to be electrically connected with an external connection terminal; and the controller is electrically connected with the high-voltage interlocking circuit and used for being electrically connected with a voltage source, and the controller is used for collecting the voltage of a connection point of the controller and the high-voltage interlocking circuit so as to determine the connection state of the external connection terminal. In the embodiment of the invention, the connection state of the high-voltage loop is detected through the low-voltage small signal, so that devices in the battery management system can be reduced, and the configuration cost is reduced. And different connection states of the external connection terminal can be determined through different voltages collected by the controller, so that effective detection of different connection states of the high-voltage loop is realized.

Description

Battery management system, battery pack and power-consuming equipment Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a battery management system, a battery pack, and an electrical device. Background Art

[0002] When designing a battery management system (BMS), the integrity of the high-voltage connector's charging and discharging power circuit must be considered to avoid unexpected disconnections and arc damage to the high-voltage connector caused by hot plugging and unplugging.

[0003] Currently, battery management systems use PWM (Pulse Width Modulation) signals to detect the integrity of high-voltage circuits. However, this method requires many components, is costly, and cannot effectively detect the connection status of high-voltage circuits.

[0004] Summary of the Invention

[0005] The purpose of the embodiments of the present application is to provide a battery management system, a battery pack and an electrical device for effectively detecting the connection status of a high-voltage circuit, and the battery management system requires fewer components and has a lower cost.

[0006] The present invention is achieved in that:

[0007] In a first aspect, an embodiment of the present application provides a battery management system, comprising: a high-voltage interlocking circuit, configured to be electrically connected to a voltage source and capable of receiving an output voltage of the voltage source, the high-voltage interlocking circuit being configured to be electrically connected to an external connection terminal; a controller, electrically connected to the high-voltage interlocking circuit and configured to be electrically connected to the voltage source, the controller being capable of collecting the voltage at a connection point between the controller and the high-voltage interlocking circuit to determine the connection status of the external connection terminal.

[0008] In an embodiment of the present application, a high-voltage interlock circuit is configured in the battery management system, and the high-voltage interlock circuit is configured to be electrically connected to the external connection terminal, and the high-voltage interlock circuit obtains the supply voltage of the voltage source. The controller determines the connection state of the external connection terminal (the connection state of the high-voltage circuit) by collecting the voltage of the connection between itself and the high-voltage interlock circuit. That is, the above method detects the connection state of the high-voltage circuit by a low-voltage small signal, which can reduce the devices in the battery management system and reduce the configuration cost. And through the different voltages collected by the controller, the different connection states of the external connection terminals can be determined, thereby achieving effective detection of the different connection states of the high-voltage circuit.

[0009] In combination with the technical solution provided in the first aspect above, in some possible implementations, the battery management system also includes a voltage divider circuit; the voltage divider circuit is configured to be electrically connected between the output end of the voltage source and the ground; the voltage divider circuit includes at least two resistors connected in series, and the first node between the resistors connected in series is electrically connected to the controller.

[0010] In an embodiment of the present application, the voltage divider circuit configured in the battery management system can provide a reference voltage for the controller, and then determine the connection status of the external connection terminal (the connection status of the high-voltage circuit) through the reference voltage and the voltage of the connection point.

[0011] In combination with the technical solution provided in the first aspect above, in some possible implementations, the high-voltage interlock circuit includes: a first resistor, a second resistor and a third resistor; wherein, the first resistor is connected in parallel with the second resistor and then in series with the third resistor to form a series branch, and the series branch is configured to be electrically connected between the output end of the voltage source and the ground, the first end of the third resistor is electrically connected to the controller, and the second end of the third resistor is grounded.

[0012] In the embodiment of the present application, the first resistor and the second resistor can play a role of current division. At the same time, the first resistor, the second resistor and the third resistor can also play a role of voltage division.

[0013] In combination with the technical solution provided in the first aspect above, in some possible implementations, the first end of the first resistor and the first end of the second resistor are configured to be electrically connected to the output end of the voltage source, the second end of the first resistor and the second end of the second resistor are configured to be electrically connected to the external connection terminal, and the second end of the second resistor is also electrically connected to the first end of the third resistor.

[0014] In the embodiment of the present application, through the above connection manner, the controller can determine different connection states of the external connection terminal according to different voltages detected at the first end of the third resistor.

[0015] In combination with the technical solution provided in the first aspect above, in some possible implementations, the high-voltage interlock circuit includes: a fourth resistor; wherein, the first resistor and the second resistor are electrically connected to the first end of the fourth resistor after being connected in parallel, and the second end of the fourth resistor is electrically connected to the controller and the first end of the third resistor, respectively.

[0016] In the embodiment of the present application, the fourth resistor connected in the above manner can be used to detect abnormalities in the external connection terminal, for example, to detect whether the external connection terminal is short-circuited with the ground.

[0017] In combination with the technical solution provided in the first aspect above, in some possible implementations, the connection status of the external connection terminal includes: normal connection state, open circuit state, short circuit state and poor connection state; wherein, the short circuit state includes at least one of the external connection terminal being short-circuited to the ground and the external connection terminal being short-circuited to the voltage source.

[0018] In the embodiment of the present application, effective detection of various connection states of the high-voltage circuit can be achieved through low-voltage small signals.

[0019] In combination with the technical solution provided in the first aspect above, in some possible implementations, the battery management system also includes a controllable switch; wherein, the controllable switch is configured to be electrically connected between the voltage source and the high-voltage interlock circuit, and can perform on-off operations in response to the control signal of the controller.

[0020] In an embodiment of the present application, the on-off operation between the voltage source and the high-voltage interlock circuit can be performed through a controllable switch, that is, the high-voltage interlock circuit is controlled to perform detection only when the high-voltage connector is inserted, thereby avoiding starting the high-voltage interlock circuit when the high-voltage connector is not inserted, thereby reducing the voltage source from supplying power to the high-voltage interlock circuit on the battery management system and reducing power consumption.

[0021] In combination with the technical solution provided in the first aspect above, in some possible implementations, the battery management system also includes a diode, the anode of the diode is configured to be electrically connected to the output end of the voltage source, and the cathode of the diode is electrically connected to the controllable switch; or, the high-voltage interlock circuit includes at least one diode, the anode of the diode is electrically connected to the controllable switch, and the cathode of the diode is electrically connected to the first resistor and / or the second resistor.

[0022] In an embodiment of the present application, when the anode of the diode is electrically connected to the output terminal of the voltage source and the cathode of the diode is electrically connected to the controllable switch, the diode can provide reverse voltage protection. When the anode of the diode is electrically connected to the controllable switch and the cathode of the diode is electrically connected to the first resistor and / or the second resistor, the diode provides reverse voltage protection for the circuit in which it is located.

[0023] In combination with the technical solution provided in the first aspect above, in some possible implementations, the battery management system also includes an input protection module; the input protection module is electrically connected between the high-voltage interlock circuit and the ground; the input protection module is used to provide electrostatic protection for the high-voltage interlock circuit.

[0024] In combination with the technical solution provided in the first aspect above, in some possible implementations, the input protection module includes: a first transient diode, a second transient diode, a first capacitor, and a second capacitor; the first end of the first transient diode and the first end of the first capacitor are both connected to the second end of the first resistor, and the second end of the first transient diode and the second end of the first capacitor are both grounded; the first end of the second transient diode and the first end of the second capacitor are both connected to the second end of the second resistor, and the second end of the second transient diode and the second end of the second capacitor are both grounded.

[0025] In combination with the technical solution provided in the first aspect above, in some possible implementations, the battery management system further includes a filtering module; the filtering module is connected between the high-voltage interlock circuit and the controller.

[0026] In the embodiment of the present application, the filtering module is mainly used to filter the sampling signal output by the high-voltage interlock circuit.

[0027] In a second aspect, an embodiment of the present application provides a battery pack, comprising: a battery cell module, a voltage source, and any one of the battery management systems provided in the first aspect; the battery management system is electrically connected to the battery cell module.

[0028] In combination with the technical solution provided in the second aspect above, in some possible implementations, the voltage source includes a DCDC module or an LDO module, and the voltage source is arranged on the battery management system. The voltage source is also electrically connected to the battery cell module, and can step down the voltage of the battery cell module to power the high-voltage interlocking circuit.

[0029] In combination with the technical solution provided in the second aspect above, in some possible implementations, the voltage source is a backup battery, and the voltage source is configured to supply power to the battery management system.

[0030] In a third aspect, an embodiment of the present application provides an electrical device, comprising any battery pack provided in the embodiment of the second aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments of the present application. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope.

[0032] FIG1 is a module block diagram of a first battery management system provided in an embodiment of the present application.

[0033] FIG2 is a module block diagram of a second battery management system provided in an embodiment of the present application.

[0034] FIG3 is a module block diagram of a third battery management system provided in an embodiment of the present application.

[0035] FIG4 is a module block diagram of a fourth battery management system provided in an embodiment of the present application.

[0036] FIG5 is a module block diagram of the fifth battery management system provided in an embodiment of the present application.

[0037] FIG6 is a module block diagram of the sixth battery management system provided in an embodiment of the present application.

[0038] FIG7 is a module block diagram of the seventh battery management system provided in an embodiment of the present application.

[0039] FIG8 is a module block diagram of an eighth battery management system provided in an embodiment of the present application.

[0040] FIG9 is a module block diagram of a ninth battery management system provided in an embodiment of the present application.

[0041] FIG10 is a module block diagram of the tenth battery management system provided in an embodiment of the present application.

[0042] FIG11 is a module block diagram of a battery pack provided in an embodiment of the present application.

[0043] FIG12 is a module block diagram of an electrical device provided in an embodiment of the present application.

[0044] Icon: 100-battery management system; 10-voltage source; 20-high-voltage interlock circuit; 30-controller; 40-voltage divider circuit; 50-controllable switch; 60-input protection module; 70-filter module; 200-battery pack; 210-battery cell module; 300-electrical equipment. DETAILED DESCRIPTION

[0045] The following embodiments of the technical solution of the present application will be described in detail with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application and are therefore only examples and are not intended to limit the scope of protection of the present application.

[0046] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned figure descriptions are intended to cover non-exclusive inclusions.

[0047] In the description of the embodiments of this application, the technical terms "first" and "second" are used only to distinguish different objects and should not be understood to indicate or imply relative importance or implicitly specify the quantity, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, the meaning of "plurality" is more than two, unless otherwise clearly and specifically defined.

[0048] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0049] In the description of the embodiments of this application, the term "and / or" is simply a description of the association relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent the following three situations: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this document generally indicates that the associated objects are in an "or" relationship.

[0050] In the description of the embodiments of the present application, unless otherwise specified or limited, the electrical connection between two components may be a direct electrical connection or an indirect electrical connection via an intermediate component. For those skilled in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0051] Currently, market developments indicate that batteries are increasingly being used. They are not only used in energy storage systems such as hydropower, thermal, wind, and solar power plants, but are also widely used in electric vehicles like electric bicycles, electric motorcycles, and electric cars, as well as in military equipment and aerospace. As battery applications continue to expand, market demand is also growing.

[0052] During use, batteries require charging and discharging, and this operation can be controlled by a battery management system. When designing a battery management system, the integrity of the high-voltage connector's charging and discharging power circuit must be considered to prevent unexpected disconnections and arcing damage caused by hot plugging and unplugging the high-voltage connector. Currently, battery management systems use PWM signals to detect the integrity of the high-voltage circuit. However, this approach requires numerous components, is costly, and cannot effectively detect the connection status of the high-voltage circuit. For example, using PWM signals to detect the high-voltage circuit cannot diagnose weak connections. Specifically, when using PWM signals to detect the high-voltage circuit, if a disconnection is detected (which may simply be due to a poor connection), a high-voltage interlock open circuit will be reported, disrupting the connection and affecting the power user experience. For example, when a battery pack equipped with a battery management system is installed in an electric motorcycle, if the high-voltage connector is weakly connected, PWM signals will be used to detect the high-voltage circuit, resulting in a high-voltage interlock open circuit signal. This will cause the electric motorcycle to lose power, affecting the driver's driving experience and impacting backup protection. For example, when a battery cluster or battery stack equipped with a battery management system is configured in an energy storage system (e.g., a home energy storage system) or an uninterruptible power supply (UPS), if a weak connection occurs in the high-voltage circuit, the PWM signal will detect the weak connection and report a high-voltage interlock open circuit, causing a power outage in the energy storage system or UPS, thereby affecting the user experience. It is understood that a battery stack can include multiple battery clusters connected in parallel, in series, or in hybrid mode. Hybrid battery clusters refer to multiple battery clusters connected both in series and in parallel.

[0053] Based on this, the inventors designed a voltage source and a high-voltage interlocking circuit in a battery management system to effectively detect the connection status of the high-voltage circuit. The battery management system requires fewer components and has a lower cost.

[0054] Referring to FIG. 1 , an embodiment of the present application provides a battery management system 100 .

[0055] In a specific implementation, the battery management system 100 may be implemented in the form of a circuit board, such as a printed circuit board (PCB). The battery management system 100 may specifically include: a high-voltage interlock circuit 20 and a controller 30 .

[0056] The high-voltage interlock circuit 20 is electrically connected to the voltage source 10 and is configured to be electrically connected to external connection terminals. Specifically, referring to FIG1 , the high-voltage interlock circuit 20 is electrically connected to two connection terminals S1 and S2 of the high-voltage interlock signal line. The high-voltage interlock circuit 20 is also electrically connected to the controller 30 via an electrical connection point.

[0057] The high-voltage interlock circuit 20 can receive the output voltage of the voltage source 10 , that is, the voltage source 10 can power the high-voltage interlock circuit 20 .

[0058] In one embodiment, the voltage source 10 may include a DCDC (Direct Current) module or an LDO (Low Dropout Regulator) module. The voltage source 10 is also used to connect to a battery module (such as a 60V lithium battery) to step down the output voltage of the battery module. The output voltage of the voltage source 10 can be 5V or 12V.

[0059] In another embodiment, the voltage source 10 may also be a backup battery, and its voltage may be 5 V or 12 V. That is, the voltage source 10 can directly provide a voltage of 5 V or 12 V to the high voltage interlock circuit 20 .

[0060] In addition, the voltage source 10 can also simultaneously power the controller 30. In this case, the power supply voltage provided by the voltage source 10 can be used as a reference voltage collected by the controller 30, thereby enabling the controller 30 to subsequently determine the connection status of the external connection terminal based on the reference voltage.

[0061] Of course, the controller 30 can also be powered by other modules. For example, the controller 30 can also be powered by another backup battery, or the battery management system 100 can also include a DCDC module, which is electrically connected to the battery module and the controller 30 to provide power to the controller 30. At the same time, the voltage source 10 is also connected to the controller 30 to provide a reference voltage for the controller 30, so that the controller 30 can subsequently determine the connection status of the external connection terminal based on the reference voltage.

[0062] The controller 30 is mainly used to collect the voltage at the connection point between the controller 30 and the high-voltage interlock circuit 20 to determine the connection status of the external connection terminal.

[0063] Specifically, the controller 30 determines the connection status of the external connection terminal by collecting the voltage of the connection point with the high-voltage interlock circuit 20 and the reference voltage provided by the voltage source 10 .

[0064] The controller 30 may be an integrated circuit chip with signal processing capabilities. The controller 30 may also be a general-purpose processor, such as a microcontroller unit (MCU), a central processing unit (CPU), a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a discrete gate or transistor logic device, or a discrete hardware component, and may implement or execute the methods, steps, and logic block diagrams disclosed in the embodiments of the present application. In addition, the general-purpose processor may be a microprocessor or any conventional processor.

[0065] The high-voltage interlock circuit 20 is configured to be electrically connected to an external connection terminal, thereby enabling the controller 30 to determine different connection states of the external connection terminal by collecting different voltages at the connection point of the high-voltage interlock circuit 20. The voltage at the connection point of the high-voltage interlock circuit 20 is a low voltage (e.g., 5-16 volts). The high-voltage interlock circuit 20 can be used to check high-voltage circuits greater than or equal to 60 volts.

[0066] It can be seen that in an embodiment of the present application, a voltage source 10 and a high-voltage interlock circuit 20 are configured in the battery management system 100. The high-voltage interlock circuit 20 is configured to be electrically connected to the external connection terminal and powered by the voltage source 10. The controller 30 determines the connection state of the external connection terminal (the connection state of the high-voltage circuit) by collecting the voltage of the connection between the controller 30 and the high-voltage interlock circuit 20. That is, the above method detects the connection state of the high-voltage circuit by a low-voltage small signal, which can reduce the devices in the battery management system and reduce the configuration cost. And the different voltages collected by the controller 30 can determine the different connection states of the external connection terminals, thereby achieving effective detection of the different connection states of the high-voltage circuit.

[0067] Referring to FIG. 2 , in some embodiments, the battery management system 100 further includes a voltage divider circuit 40 . The voltage divider circuit 40 is electrically connected to the output terminal of the voltage source 10 and to ground.

[0068] The voltage divider circuit 40 includes at least two resistors connected in series, and a first node between the resistors connected in series is electrically connected to the controller 30 .

[0069] As shown in FIG2 , the voltage divider circuit 40 may include a resistor R11 and a resistor R12. Resistors R11 and R12 are connected in series, with a first end of resistor R11 electrically connected to the output terminal of the voltage source 10, a second end of resistor R11 electrically connected to a first end of resistor R12, and a second end of resistor R12 connected to ground. Any node between the second end of resistor R11 and the first end of resistor R12 may serve as a first node and be connected to the controller 30.

[0070] The controller 30 collects the voltage V1 of the first node and then calculates the reference voltage V provided by the voltage source 10. F Among them, V F The specific calculation formula is:

[0071]

[0072] In other embodiments, the voltage divider circuit 40 may further include three resistors connected in series or four resistors connected in series. In this case, the first node may be a connection node between any two resistors. When the voltage divider circuit 40 further includes three resistors connected in series or four resistors connected in series, the reference voltage V F The calculation formula can be made by adaptively changing formula (1).

[0073] It can be seen that in the embodiment of the present application, the voltage divider circuit 40 configured in the battery management system 100 can provide a reference voltage for the controller 30, and then determine the connection status of the external connection terminal (the connection status of the high-voltage circuit) through the reference voltage and the voltage of the connection point.

[0074] Referring to FIG. 3 , in some embodiments, the high-voltage interlock circuit 20 may specifically include: a first resistor R21 , a second resistor R22 , and a third resistor R23 .

[0075] The first resistor R21 and the second resistor R22 are connected in parallel, and then connected in series with the third resistor R23 between the output terminal of the voltage source 10 and ground. The first end of the third resistor R23 is electrically connected to the controller 30, and the second end of the third resistor R23 is grounded. The first end of the third resistor R23 is the connection point between the controller 30 and the high-voltage interlock circuit 20, and the controller 30 can collect the voltage at the first end of the third resistor R23.

[0076] The first resistor R21 and the second resistor R22 can perform a current shunting function. Meanwhile, the first resistor R21, the second resistor R22 and the third resistor R23 can also perform a voltage dividing function.

[0077] The first end of the first resistor R21 and the first end of the second resistor R22 are both electrically connected to the output terminal of the voltage source 10, and the second end of the first resistor R21 and the second end of the second resistor R22 are both configured to be electrically connected to an external connection terminal. As shown in FIG3 , the second end of the first resistor R21 is connected to the external connection terminal S1, and the second end of the second resistor R22 is connected to the external connection terminal S2. The second end of the second resistor R22 is also electrically connected to the first end of the third resistor R23.

[0078] Through the above connection manner, the controller 30 can determine different connection states of the external connection terminal according to different voltages detected at the first end of the third resistor R23.

[0079] The following describes the process of determining the above-mentioned connection states using the battery management system 100 shown in FIG. 3 .

[0080] In this embodiment of the present application, the reference voltage V F The connection state of the external connection terminal is determined by the voltage V2 at the connection point between the controller 30 and the high-voltage interlock circuit 20 (hereinafter referred to as the connection point voltage V2).

[0081] When the connection state of the external connection terminal is normal, the reference voltage V F The voltage V2 at the connection point satisfies the following formula:

[0082]

[0083] In formula (2), the reference voltage V F It can be obtained by formula (1), that is, after the controller 30 collects the voltage V1 of the first node, it first calculates the voltage V1 of the first node by formula (1) to obtain the reference voltage V F , and then combined with the connection point voltage V2 to determine whether formula (2) is satisfied. If formula (2) is satisfied, it is determined that the connection state of the external connection terminal is a normal connection state.

[0084] When the external connection terminal is in an open circuit state, the reference voltage V F The voltage V2 at the connection point satisfies the following formula:

[0085]

[0086] In formula (3), the reference voltage V F It can be obtained by formula (1), that is, after the controller 30 collects the voltage of the first node, it first calculates the voltage V1 of the first node by formula (1) to obtain the reference voltage V F, and then combined with the connection point voltage V2 to determine whether formula (3) is satisfied. If formula (3) is satisfied, it is determined that the connection state of the external connection terminal is an open circuit state.

[0087] When the external connection terminal is in a short-circuit state, and the short-circuit state is a short circuit between the external connection terminal and ground, the connection point voltage V2 = 0 V. It should be noted that since the external connection terminal is directly shorted to ground, no current reaches the controller 30 . Therefore, at this time, the voltage at the connection point collected by the controller 30 is 0 V.

[0088] When the connection state of the external connection terminal is short-circuited, and the short-circuit state is when the external connection terminal is short-circuited with the voltage source, the reference voltage V F The voltage V2 at the connection point satisfies the following formula:

[0089] V2=V F (4)

[0090] When the short circuit state is that the external connection terminal is short-circuited with the voltage source, the connection point is directly connected to the power source, that is, V2 = V F Therefore, if V2 collected by the controller 30 satisfies formula (4), it is determined that the connection state of the external connection terminal is a short-circuit state, and the short-circuit state specifically means that the external connection terminal is short-circuited with the voltage source.

[0091] When the controller 30 determines that the connection state of the external connection terminal is not the normal connection state, the open state, or the short state, the controller 30 determines that the connection state of the external connection terminal is a poor connection state.

[0092] When the connection status of the external connection terminal is a poor connection state, the reference voltage V F The voltage V2 at the connection point satisfies the following formula:

[0093]

[0094] In formula (5), R represents the resistance value between the external connection terminals when the connection state of the external connection terminals is a poor connection state.

[0095] The specific value of the high-voltage interlocking circuit resistance R can be calculated by reverse calculation using formula (5). The specific calculation formula is:

[0096]

[0097] In formula (6), the resistance value R between the external connection terminals can be used to determine the strength of the connection in a poor connection state. The larger the value of the high-voltage interlock circuit resistance value R, the weaker the connection, and the smaller the value of the resistance value R between the external connection terminals, the stronger the connection. The battery management system 100 can determine the subsequent control strategy based on the strength of the connection in the poor connection state. For example, when the connection is strong, the power interruption can be delayed. This application does not limit this.

[0098] In addition, in some embodiments, an error constant can be introduced. That is, in the process of determining whether the connection state of the external connection terminal is a normal connection state, an open circuit state, and a short circuit state, an error constant can be introduced into formulas (2) to (4), thereby reducing the influence of environmental factors on the detection results.

[0099] Please refer to FIG. 4 , in some embodiments, the high-voltage interlock circuit 20 further includes a fourth resistor R24 ​​.

[0100] The first resistor R21 and the second resistor R22 are connected in parallel and electrically connected to a first end of a fourth resistor R24 ​​. A second end of the fourth resistor R24 ​​is electrically connected to the controller 30 and a first end of the third resistor R23 .

[0101] In the embodiment of the present application, the fourth resistor R24 ​​connected in the above manner can be used to detect abnormalities in the external connection terminal, for example, to detect whether the external connection terminal is short-circuited with the ground.

[0102] Specifically, the connection status of the external connection terminal includes: normal connection state, open circuit state, short circuit state and poor connection state; wherein the short circuit state includes at least one of the external connection terminal being short-circuited with the ground and the external connection terminal being short-circuited with the voltage source 10 (the input end of the voltage source 10).

[0103] The following describes the process of determining the above-mentioned connection states using the battery management system 100 shown in FIG. 4 .

[0104] In this embodiment of the present application, the reference voltage V F The connection state of the external connection terminal is determined by the voltage V2 at the connection point between the controller 30 and the high-voltage interlock circuit 20 (hereinafter referred to as the connection point voltage V2).

[0105] When the connection state of the external connection terminal is normal, the reference voltage V F The voltage V2 at the connection point satisfies the following formula:

[0106]

[0107] In formula (7), the reference voltage V FIt can be obtained by formula (1), that is, after the controller 30 collects the voltage V1 of the first node, it first calculates the voltage V1 of the first node by formula (1) to obtain the reference voltage V F , and then combined with the connection point voltage V2 to determine whether formula (7) is satisfied. If formula (7) is satisfied, it is determined that the connection state of the external connection terminal is a normal connection state.

[0108] When the external connection terminal is in an open circuit state, the reference voltage V F The voltage V2 at the connection point satisfies the following formula:

[0109]

[0110] In formula (8), the reference voltage V F It can be obtained by formula (1), that is, after the controller 30 collects the voltage of the first node, it first calculates the voltage V1 of the first node by formula (1) to obtain the reference voltage V F , and then combined with the connection point voltage V2 to determine whether formula (8) is satisfied. If formula (8) is satisfied, it is determined that the connection state of the external connection terminal is an open circuit state.

[0111] When the external connection terminal is in a short-circuit state, and the short-circuit state is when the external connection terminal is shorted to ground, the connection point voltage V2 = 0 V. It should be noted that since the external connection terminal is directly shorted to ground, no current flows through the fourth resistor R24 ​​to reach the controller 30. Therefore, at this time, the voltage at the second end of the fourth resistor R24 ​​collected by the controller 30 is 0 V.

[0112] When the connection state of the external connection terminal is short-circuited, and the short-circuit state is when the external connection terminal is short-circuited with the voltage source, the reference voltage V F The voltage V2 at the connection point satisfies the following formula:

[0113]

[0114] In formula (9), the reference voltage V F It can be obtained by formula (1), that is, after the controller 30 collects the voltage V1 of the first node, it first calculates the voltage V1 of the first node by formula (1) to obtain the reference voltage V F , and then combined with the connection point voltage V2 to determine whether formula (9) is satisfied. If formula (9) is satisfied, it is determined that the connection state of the external connection terminal is a short-circuit state, and the short-circuit state is specifically that the external connection terminal is short-circuited with the voltage source.

[0115] When the controller 30 determines that the connection state of the external connection terminal is not the normal connection state, the open state, or the short state, the controller 30 determines that the connection state of the external connection terminal is a poor connection state.

[0116] When the connection status of the external connection terminal is a poor connection state, the reference voltage V F The voltage V2 at the connection point satisfies the following formula:

[0117]

[0118] In formula (10), R represents the resistance value between the external connection terminals when the connection state of the external connection terminals is a poor connection state.

[0119] The specific value of the high-voltage interlocking circuit resistance R can be calculated by reverse calculation using formula (10). The specific calculation formula is:

[0120]

[0121] In formula (11), the resistance value R between the external connection terminals can be used to determine the strength of the connection in a poor connection state. The larger the value of the high-voltage interlock circuit resistance value R, the weaker the connection, and the smaller the value of the resistance value R between the external connection terminals, the stronger the connection. The battery management system 100 can determine the subsequent control strategy based on the strength of the connection in the poor connection state. For example, when the connection is strong, the power interruption can be delayed. This application does not limit this.

[0122] In addition, in some embodiments, an error constant can be introduced. That is, in the process of determining whether the connection state of the external connection terminal is a normal connection state, an open circuit state, and a short circuit state, an error constant can be introduced into formulas (7) to (9), thereby reducing the influence of environmental factors on the detection results.

[0123] It should be noted that the above formula is the formula corresponding to when the high-voltage interlock circuit 20 includes a first resistor R21, a second resistor R22, a third resistor R23 and a fourth resistor R24. When the high-voltage interlock circuit 20 includes more or fewer resistors, the above formula can be adaptively changed.

[0124] In summary, the low-voltage small signal can be used to effectively detect various connection states of the high-voltage circuit (including normal connection state, open circuit state, short circuit state and poor connection state).

[0125] Referring to FIG. 5 , in some embodiments, the battery management system 100 further includes a controllable switch 50 .

[0126] The controllable switch 50 is electrically connected between the voltage source 10 and the high-voltage interlock circuit 20 , and can perform on-off operations in response to a control signal from the controller 30 .

[0127] The controllable switch 50 can be used to perform on-off operations between the voltage source 10 and the high-voltage interlock circuit 20, that is, the high-voltage interlock circuit 20 is controlled to perform detection only when the high-voltage connector is inserted, thereby avoiding starting the high-voltage interlock circuit when the high-voltage connector is not inserted, thereby reducing the power supply of the voltage source 10 to the high-voltage interlock circuit 20 on the battery management system 100 and reducing power consumption.

[0128] In one embodiment, the controllable switch 50 is a PMOS transistor Q1. The gate of the PMOS transistor Q1 is connected to the controller 30. The source of the PMOS transistor Q1 is connected to the output terminal of the voltage source 10, and the drain of the PMOS transistor Q1 is connected to the high-voltage interlock circuit 20, specifically, the first resistor R21 and the second resistor R22 in the high-voltage interlock circuit 20.

[0129] When the battery management system 100 wakes up and is in normal working state, the PMOS transistor Q1 is controlled to be turned on. When the battery management system 100 is in sleep mode, the PMOS transistor Q1 is controlled to be turned off. It is understood that a controllable switch driving circuit (not shown) can be electrically connected between the controller 30 and the controllable switch 50, and the controller 30 and the driving circuit can control the on and off of the controllable switch.

[0130] Referring to FIG6 , in another embodiment, the controllable switch 50 is a PNP transistor Q2 . The emitter of the PNP transistor Q2 is connected to the output of the voltage source 10 , the base of the PNP transistor Q2 is connected to the controller 30 , and the collector of the PNP transistor Q2 is connected to the high-voltage interlock circuit 20 , specifically, the first resistor R21 and the second resistor R22 in the high-voltage interlock circuit 20 .

[0131] In some embodiments, the battery management system 100 further includes a diode.

[0132] 7 , in one embodiment, the anode of the diode D1 is electrically connected to the output terminal of the voltage source 10, and the cathode of the diode D1 is electrically connected to the controllable switch 50. The diode can provide reverse voltage protection.

[0133] When the connection method shown in FIG7 is used, when the external connection terminal is short-circuited with the voltage source, the reference voltage V F The formula satisfied by the connection point voltage V2 is specifically:

[0134]

[0135] In formula (12), represents the forward conduction voltage drop of diode D1.

[0136] In another embodiment, the high-voltage interlock circuit 20 may further include at least one diode, wherein the anode of the diode is electrically connected to the controllable switch 50, and the cathode of the diode is electrically connected to the first resistor R21 and / or the second resistor R22. The at least one diode included in the high-voltage interlock circuit 20 can provide reverse voltage protection for the circuit.

[0137] Referring to FIG8 , the high-voltage interlock circuit 20 may illustratively include a diode D2 and a diode D3. The anode of the diode D2 is electrically connected to the controllable switch 50. The cathode of the diode D2 is electrically connected to the first resistor R21. The anode of the diode D3 is electrically connected to the controllable switch 50. The cathode of the diode D3 is electrically connected to the second resistor R22.

[0138] Referring to FIG. 9 , in some embodiments, the battery management system 100 further includes an input protection module 60 .

[0139] The input protection module 60 is electrically connected between the high-voltage interlock circuit 20 and the ground; the input protection module 60 is used to provide electrostatic protection for the high-voltage interlock circuit 20 and also to provide transient surge protection for external connection terminals.

[0140] Optionally, the input protection module 60 may specifically include: a first transient state diode Z31 , a second transient state diode Z32 , a first capacitor C31 , and a second capacitor C32 .

[0141] A first end of the first transient diode Z31 and a first end of the first capacitor C31 are electrically connected to the second end of the first resistor R21, and a second end of the first transient diode Z31 and a second end of the first capacitor C31 are grounded. A first end of the second transient diode Z32 and a first end of the second capacitor C32 are connected to the second end of the second resistor R22, and a second end of the second transient diode Z32 and a second end of the second capacitor C32 are grounded.

[0142] Referring to FIG. 10 , in some embodiments, the battery management system 100 further includes a filtering module 70 .

[0143] The filter module 70 is connected between the high voltage interlock circuit 20 and the controller 30 .

[0144] In the embodiment of the present application, the filtering module 70 is mainly used to filter the sampling signal output by the high-voltage interlock circuit 20 .

[0145] Optionally, the filter module 70 may specifically include a resistor R41 and a capacitor C41. A first end of the resistor R41 is connected to the second end of the fourth resistor R24, and a second end of the resistor R41 is electrically connected to the controller 30. A first end of the capacitor C41 is electrically connected to the second end of the resistor R41, and a second end of the capacitor C41 is connected to ground.

[0146] 11 , an embodiment of the present application provides a battery pack 200 including a cell module 210 , a voltage source 10 , and the battery management system 100 provided in the above embodiment. The battery management system 100 is electrically connected to the voltage source 10 and the cell module 210 .

[0147] In the embodiment of the present application, the battery cell module 210 may be a battery cell module with a voltage higher than 60 volts.

[0148] In one embodiment, the voltage source 10 may include a DCDC module or an LDO module. The voltage source 10 is also connected to the battery module 210 to step down the output voltage of the battery module 210. The output voltage of the voltage source 10 may be 5V or 12V.

[0149] In another embodiment, the voltage source 10 may also be a backup battery, and its voltage may be 5 V or 12 V. The voltage source 10 can directly provide a voltage of 5 V or 12 V to the high voltage interlock circuit.

[0150] Please refer to FIG. 12 . An embodiment of the present application provides an electric device 300 , including a battery pack 200 .

[0151] It should be noted that the embodiment of the present application provides an electric device 300 that uses a battery module 210 as a power source. The electric device 300 may be, but is not limited to, an electric two-wheeled vehicle (such as a battery-powered vehicle, an electric bicycle, etc.), an electric motorcycle, an electric tricycle, an electric vehicle, an energy storage system, and the like.

[0152] 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. 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 or all 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, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural or step conflict, the various technical features mentioned in each embodiment can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A battery management system, characterized in that: The battery management system includes: a high-voltage interlock circuit configured to be electrically connected to a voltage source and capable of receiving an output voltage of the voltage source, wherein the high-voltage interlock circuit is configured to be electrically connected to an external connection terminal; A controller is electrically connected to the high-voltage interlock circuit and is configured to be electrically connected to the voltage source. The controller is capable of collecting the voltage at the connection point between the controller and the high-voltage interlock circuit to determine the connection status of the external connection terminal.

2. The battery management system according to claim 1, characterized in that: The battery management system further includes a voltage divider circuit; the voltage divider circuit is configured to be electrically connected between the output terminal of the voltage source and the ground; The voltage divider circuit includes at least two resistors connected in series, and a first node between the resistors connected in series is electrically connected to the controller.

3. The battery management system according to claim 1 or 2, characterized in that: The high voltage interlock circuit comprises: a first resistor, a second resistor and a third resistor; The first resistor and the second resistor are connected in parallel and in series with the third resistor to form a series branch, and the series branch is configured to be electrically connected between the output end of the voltage source and the ground. The first end of the third resistor is electrically connected to the controller, and the second end of the third resistor is grounded.

4. The battery management system according to claim 3, characterized in that: The first end of the first resistor and the first end of the second resistor are configured to be electrically connected to the output end of the voltage source, the second end of the first resistor and the second end of the second resistor are configured to be electrically connected to the external connection terminal, and the second end of the second resistor is also electrically connected to the first end of the third resistor.

5. The battery management system according to claim 3, characterized in that: The high-voltage interlock circuit includes: a fourth resistor; The first resistor and the second resistor are connected in parallel and electrically connected to the first end of the fourth resistor. The second end of the fourth resistor is electrically connected to the controller and the first end of the third resistor respectively.

6. The battery management system according to any one of claims 1 to 5, characterized in that: The connection status of the external connection terminal includes: normal connection state, open circuit state, short circuit state and poor connection state; The short-circuit state includes at least one of the external connection terminal being short-circuited with the ground and the external connection terminal being short-circuited with the voltage source.

7. The battery management system according to claim 3, characterized in that: The battery management system further includes a controllable switch; The controllable switch is configured to be electrically connected between the voltage source and the high-voltage interlock circuit, and is capable of performing on-off operations in response to a control signal from the controller.

8. The battery management system according to claim 7, characterized in that: The battery management system further includes a diode, wherein an anode of the diode is configured to be electrically connected to the output terminal of the voltage source, and a cathode of the diode is electrically connected to the controllable switch; or, The high-voltage interlock circuit includes at least one diode, an anode of the diode is electrically connected to the controllable switch, and a cathode of the diode is electrically connected to the first resistor and / or the second resistor.

9. The battery management system according to claim 4, characterized in that: The battery management system further includes an input protection module; The input protection module is electrically connected between the high-voltage interlock circuit and the ground; the input protection module is used to provide electrostatic protection for the high-voltage interlock circuit.

10. The battery management system according to claim 9, characterized in that: The input protection module includes: a first transient diode, a second transient diode, a first capacitor and a second capacitor; The first end of the first transient diode and the first end of the first capacitor are both connected to the second end of the first resistor, and the second end of the first transient diode and the second end of the first capacitor are both grounded; The first end of the second transient state diode and the first end of the second capacitor are both connected to the second end of the second resistor, and the second end of the second transient state diode and the second end of the second capacitor are both grounded.

11. The battery management system according to claim 3, characterized in that: The battery management system further includes a filtering module; The filter module is connected between the high-voltage interlock circuit and the controller.

12. A battery pack, characterized in that: include: A battery cell module, a voltage source, and a battery management system according to any one of claims 1 to 11; The battery management system is electrically connected to the battery cell module.

13. The battery pack according to claim 12, wherein: The voltage source includes a DCDC module or an LDO module. The voltage source is arranged on the battery management system. The voltage source is also electrically connected to the battery cell module and can step down the voltage of the battery cell module to power the high-voltage interlocking circuit.

14. The battery pack according to claim 12, wherein: The voltage source is a backup battery, and the voltage source is configured to supply power to the battery management system.

15. An electrical device, characterized in that: Comprising the battery pack according to any one of claims 12 to 14.

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