Battery management system, battery system and electric device

Abstract

The utility model discloses a battery management system, a battery system and an electric device. The battery management system comprises n first sampling branches, each first sampling branch is connected with a first end and a second end of a diverter, the first sampling branches are used for collecting signals of the first end and the second end of the diverter, and n is an integer greater than 1; the battery management system further comprises a processor, the processor is connected with the n first sampling branches, the processor is used for determining current flowing through the shunt according to signals collected by the n first sampling branches, and the processor is further used for determining the current collected by one of the first sampling branches as first current for any two first sampling branches and determining the current collected by the other first sampling branch as second current for any two second sampling branches. And determining the current collected by the other first sampling branch as a second current, selecting one of the first current and the second current with effectiveness, and determining the one as the current flowing through the shunt. According to the embodiment of the invention, the accuracy of current detection can be improved.

Description

Technical Field

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

[0002] In order to ensure that the car power battery can be charged and discharged safely and stably, the battery management system (BMS) needs to monitor the size of the power battery charge and discharge current in real time to ensure that the charge and discharge current is within the range allowed by the battery capacity. In order to achieve the above purpose, a stable and reliable current detection function is essential. Utility Model Content

[0003] The present application provides a battery management system, a battery system and an electrical device, which can improve the accuracy of current detection.

[0004] In a first aspect, the present application provides a battery management system, comprising n first sampling branches, each first sampling branch being connected to a first end and a second end of a shunt, the first sampling branch being used to collect signals from the first end and the second end of the shunt, wherein n is an integer greater than 1; the battery management system also comprises a processor, the processor being connected to the n first sampling branches, the processor being used to determine a current flowing through the shunt based on the signals collected by the n first sampling branches, the processor being further used to: for any two first sampling branches, determine that a current collected by one of the first sampling branches is a first current, determine that a current collected by the other first sampling branch is a second current, select one of the first current and the second current that is valid, and determine it as the current flowing through the shunt.

[0005] According to the battery management system provided in the embodiment of the present application, a plurality of first sampling branches are provided, so that in the event that one or some of the first sampling branches fail, other first sampling branches can be used to collect signals, thereby realizing a redundant design, and effectively preventing the problem of failure of the current monitoring function caused by the failure of one or some of the first sampling branches, thereby improving the reliability of the current detection function. In addition, in the embodiment of the present application, the processor can determine whether the current collected in the plurality of first sampling circuits is valid, and select the valid current as the current flowing through the shunt, so that the processor has a selection space, that is, the processor can select from the plurality of currents the current that can correctly characterize the current actually passing through the shunt, thereby improving the accuracy of the current detection function.

[0006] In a possible implementation of the first aspect, different first sampling branches are connected to the first end of the shunt through different first signal lines, and different first sampling branches are connected to the second end of the shunt through different second signal lines.

[0007] In an embodiment of the present application, signals at the first and second ends of the shunt are provided to different first sampling branches through different first signal lines and second signal lines. In this way, when one or some of the first signal lines and / or the second signal lines fail, other first signal lines and second signal lines can be used to transmit signals to the first sampling branches, thereby achieving a redundant design. This can effectively prevent the problem of failure of the current monitoring function caused by failure of one or some of the first signal lines and / or the second signal lines, thereby improving the reliability of the current detection function.

[0008] In a possible implementation of the first aspect, the first sampling branch includes a first signal conditioning module and an analog-to-digital converter, the input end of the first signal conditioning module is connected to the first end and the second end of the shunt, and the output end of the first signal conditioning module is connected to the input end of the analog-to-digital converter; the first signal conditioning module is used to filter and / or amplify the signal; and the analog-to-digital converter is used to convert the analog signal into a digital signal.

[0009] In the embodiment of the present application, each first battery management system includes a first signal conditioning module and an analog-to-digital signal converter, so that when one or more of the first signal conditioning modules and / or the analog-to-digital signal converters fail, other first signal conditioning modules and analog-to-digital signal converters can be used to transmit the signals at both ends of the shunt, thereby realizing a redundant design and effectively preventing the problem of failure of the current monitoring function caused by failure of one or more of the first signal conditioning modules and / or the digital signal converters, thereby improving the reliability of the current detection function.

[0010] In a possible implementation of the first aspect, if both the first current and the second current are valid and the difference between the first current and the second current is within a preset range, then any one of the first current and the second current is selected and determined as the current flowing through the shunt; if both the first current and the second current are valid and the difference between the first current and the second current is not within the preset range, then the larger one of the first current and the second current is selected and determined as the current flowing through the shunt; if the first current is valid and the second current is not valid, the first current is selected and determined as the current flowing through the shunt; if the second current is valid and the first current is not valid, the second current is selected and determined as the current flowing through the shunt.

[0011] In the embodiment of the present application, the processor can receive multiple first sampling circuits to collect multiple currents, and according to different situations of the multiple currents, can select the most appropriate current as the current flowing through the shunt, thereby improving the accuracy of the current detection function.

[0012] In a possible implementation of the first aspect, the shunt is connected in series to the target circuit, and the battery management system also includes a first drive module, which is connected to the processor. The processor is also used to control the first drive module to drive the target circuit to disconnect when it is determined that the current flowing through the shunt is greater than the current threshold.

[0013] In an embodiment of the present application, when the processor determines that the current flowing through the shunt is greater than the current threshold, the first drive module can be controlled to directly drive the target circuit to disconnect, thereby quickly cutting off the target circuit, that is, the charging and discharging circuit of the power battery can be quickly cut off, so that the power battery can quickly enter a safe state, which is beneficial to protecting the power battery.

[0014] In a possible implementation of the first aspect, the shunt is connected in series to the target circuit, the battery management system also includes a second sampling branch, the second sampling branch includes a comparator and a second drive module, the input end of the comparator is connected to the first end and the second end of the shunt, the output end of the comparator is connected to the second drive module, and the comparator controls the second drive module to drive the target circuit to disconnect when the voltage difference between the first end and the second end of the shunt is greater than a threshold voltage.

[0015] In the embodiment of the present application, the voltage at both ends of the alloy resistor is reversely inferred by using the collected current and the resistance value in the shunt, so as to ensure that the alloy resistor is in a normal working state and is not damaged by excessive voltage, thereby avoiding the problem of reduced current detection accuracy caused by damage to the alloy resistor. In addition, in the case where the second signal conditioning module, the comparator and the second drive module in the second sampling branch are all analog circuits, once it is determined that the collected current exceeds the preset threshold, the battery charging and discharging circuit can be quickly cut off by the second drive module, so that the power battery quickly enters a safe state without being limited by the running speed of the software in the processor.

[0016] In a possible implementation of the first aspect, the second sampling branch also includes a second signal conditioning module, and the input end of the comparator is connected to the first end and the second end of the shunt through the second signal conditioning module; the second signal conditioning module is used to filter and / or amplify the signal.

[0017] In an embodiment of the present application, the signal is filtered and / or amplified by a second signal conditioning circuit, so that the comparator can receive high-quality signals, improve the accuracy of the comparator, and thus better protect the dynamic point battery.

[0018] Based on the same inventive concept, in a second aspect, an embodiment of the present application provides a battery system, including a battery and a battery management system as described in any embodiment of the first aspect.

[0019] Based on the same inventive concept, in a third aspect, an embodiment of the present application provides an electrical device, comprising a battery system as described in any embodiment of the first aspect.

[0020] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The features, advantages and technical effects of exemplary embodiments of the present application will be described below with reference to the accompanying drawings.

[0022] Figure 1 A schematic diagram of the structure of a flow divider;

[0023] Figure 2 A schematic diagram of the architecture of a battery management system provided in an embodiment of the present application is shown;

[0024] Figure 3 A schematic diagram of the architecture of another battery management system provided in an embodiment of the present application is shown;

[0025] Figure 4 A schematic diagram of the architecture of another battery management system provided in an embodiment of the present application is shown;

[0026] Figure 5 A schematic diagram showing the connection between a current splitter and a target circuit provided by an embodiment of the present application is shown;

[0027] Figure 6 A schematic diagram of the architecture of another battery management system provided in an embodiment of the present application is shown;

[0028] Figure 7 A schematic diagram of the architecture of another battery management system provided in an embodiment of the present application is shown;

[0029] Figure 8 A schematic diagram of the structure of current detection of a comparative example is shown.

[0030] Description of reference numerals:

[0031] 100, shunt; 110, alloy resistor; 120, metal terminal part; 130, threaded hole;

[0032] 200. Battery management system;

[0033] 210, first sampling branch; 211, first signal conditioning module; 212, analog-to-digital converter; L1, first signal line; L2, second signal line;

[0034] 220, processor;

[0035] 230. A first driving module;

[0036] 300, target circuit; 1, power battery; 2, high voltage load; 3, total negative relay;

[0037] 240. A second sampling branch; 241. A comparator; 242. A second driving module; 243. A second signal conditioning module. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0039] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as those commonly understood by technicians in the technical field of this application; the terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned drawings and any variations thereof are intended to cover non-exclusive inclusions. The terms "first", "second", etc. in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order or a primary and secondary relationship.

[0040] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", and "attached" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0041] With the development of science and technology and the enhancement of people's awareness of environmental protection, the number of electric vehicles has gradually increased, and electric vehicles have gradually become an indispensable means of transportation in people's daily lives. The power battery in an electric vehicle can provide power for the electric vehicle and is one of the most important components of an electric vehicle. In order to ensure the safety of the power battery and maintain the performance of the power battery, the BMS needs to ensure that the charge and discharge current generated by the power battery during charging and discharging is within the range allowed by the battery capacity.

[0042] In the related art, the charge and discharge current value of the power battery can be detected by a shunt, wherein the shunt can be an instrument for measuring current, which is made based on the principle that a voltage is generated across a resistor when current passes through the resistor. Figure 1 is a schematic diagram of the structure of a flow divider 100, such as Figure 1 As shown, an alloy resistor 110 is provided in the middle of the shunt 100, and a metal terminal component 120 is provided at the left and right ends of the shunt 100. In addition, each of the metal terminal components 120 also includes a threaded hole 130 for fixing the shunt 100. The electrical signals at both ends of the alloy resistor 110 can be introduced into the BMS through the connector and / or the wiring harness, so that the BMS can determine the charge and discharge current of the power battery.

[0043] However, in the related art, if a connector and / or wiring harness fails, the BMS loses the ability to monitor the shunt current, that is, the BMS cannot determine the current of the power battery during charging and discharging.

[0044] In view of the above technical problems, the embodiments of the present application provide a battery management system, a battery system and an electric device. The battery management system provided by the embodiments of the present application is first introduced below.

[0045] Figure 2 FIG. 1 shows a schematic diagram of the architecture of a battery management system provided by an embodiment of the present application. Figure 2 As shown, the battery management system 200 includes n first sampling branches 210, each of which is connected to the first end and the second end of the shunt 100, and the first sampling branch 210 is used to collect signals from the first end and the second end of the shunt 100, where n is an integer greater than 1.

[0046] Exemplarily, the first sampling branch may be used to collect voltage signals at the first end and the second end of the shunt 100 .

[0047] Exemplarily, the first end and the second end of the shunt may be two ends of the alloy resistor in the shunt. For example, the first end of the shunt may be Figure 1 The left end of the alloy resistor 110 is shown, and the second end of the shunt can be Figure 1 The right end of the alloy resistor 110 is shown. It can be understood that the above embodiments are only for illustrative purposes.

[0048] According to the battery management system provided in the embodiment of the present application, a plurality of first sampling branches are provided. Thus, in the event that one or some of the first sampling branches fail, other first sampling branches can be used to collect signals, thereby realizing a redundant design. The problem of failure of the current monitoring function caused by the failure of one or some of the first sampling branches can be effectively prevented, thereby improving the reliability of the current detection function.

[0049] In some optional embodiments, different first sampling branches are connected to the first end of the shunt through different first signal lines L1, and different first sampling branches are connected to the second end of the shunt through different second signal lines L2.

[0050] Exemplarily, the first signal line and the second signal line are respectively used to transmit signals at both ends of the alloy resistor of the shunt, including the signal at the first end and the signal at the second end.

[0051] The first sampling branch can receive the signal of the first end and the signal of the second end corresponding to the alloy resistor in the shunt through the first signal line and the second signal. For different first sampling branches, different first signal lines and second signals can be used to transmit the signals at both ends of the alloy resistor of the shunt.

[0052] In an embodiment of the present application, signals at the first and second ends of the shunt are provided to different first sampling branches through different first signal lines and second signal lines. In this way, when one or some of the first signal lines and / or the second signal lines fail, other first signal lines and second signal lines can be used to transmit signals to the first sampling branches, thereby achieving a redundant design. This can effectively prevent the problem of failure of the current monitoring function caused by failure of one or some of the first signal lines and / or the second signal lines, thereby improving the reliability of the current detection function.

[0053] In some optional embodiments, such as Figure 3 As shown, the first sampling branch 210 includes a first signal conditioning module 211 and an analog to digital converter (ADC) 212. The input end of the first signal conditioning module 211 is connected to the first end and the second end of the shunt 100, and the output end of the first signal conditioning module 211 is connected to the input end of the analog to digital converter 212; the first signal conditioning module 211 is used to filter and / or amplify the signal; the analog to digital converter 212 is used to convert the analog signal into a digital signal.

[0054] Exemplarily, the structure and / or parameters of the first signal conditioning module in the first sampling branch may be related to the performance of the ADC.

[0055] In one example, the composition of the first signal conditioning module in different first sampling branches can be designed and matched according to the characteristics of the ADC. For example, the amplification factor of the first signal conditioning module can be designed according to the detection accuracy of the ADC; or the filtering parameters of the first signal conditioning module can be designed according to the sampling frequency of the ADC; etc.

[0056] Exemplarily, the first signal conditioning modules and analog-to-digital converters in different first sampling branches may be different, or the first signal conditioning modules and analog-to-digital converters in different first sampling branches may be the same. In one example, the ADC characteristics of different first sampling branches may be the same or different. For example, taking into account both cost and accuracy, at least one first sampling branch with relatively high sampling accuracy may be designed.

[0057] It is understandable that the structures and operations of the first signal conditioning module 211 and the analog-to-digital converter 212 are well known to those skilled in the art, and therefore, they are not described in detail in the embodiments of the present application.

[0058] In the embodiment of the present application, each first battery management system includes a first signal conditioning module and an analog-to-digital signal converter, so that when one or more of the first signal conditioning modules and / or the analog-to-digital signal converters fail, other first signal conditioning modules and analog-to-digital signal converters can be used to transmit the signals at both ends of the shunt, thereby realizing a redundant design and effectively preventing the problem of failure of the current monitoring function caused by failure of one or more of the first signal conditioning modules and / or the digital signal converters, thereby improving the reliability of the current detection function.

[0059] In order to realize the calculation of the current flowing through the shunt, as another implementation method in the embodiments of the present application, the present application also provides another architecture of the battery management system, please refer to the following embodiments for details.

[0060] Figure 3 FIG. 2 shows a schematic diagram of the architecture of another battery management system provided by an embodiment of the present application. Figure 3 As shown, the battery management system 200 further includes a processor 220 , which is connected to the n first sampling branches 210 . The processor 220 is used to determine the current flowing through the shunt according to the signals collected by the n first sampling branches 210 .

[0061] Exemplarily, the processor may be a microcontroller unit (MCU).

[0062] Exemplarily, the processor may be connected to the ADC in the first sampling branch, so as to calculate the current flowing through the shunt according to the output of the ADC, such as a voltage value represented by a digital signal, and the resistance value of the alloy resistor in the shunt.

[0063] In the embodiment of the present application, n first sampling branches 210 share one processor 220, which can reduce costs.

[0064] Since the structures and performances of the first signal conditioning modules and ADCs in different first sampling circuits may be different, the accuracy of the signals output by the first signal conditioning modules and ADCs may be different. Furthermore, the current flowing through the shunt calculated by the processor using the output signal and the resistance value of the alloy resistor may also be different.

[0065] In some optional embodiments, the processor 220 can also be used to: for any two first sampling branches 210, determine that the current collected by one of the first sampling branches 210 is the first current, determine that the current collected by the other first sampling branch 210 is the second current, select the one of the first current and the second current that is valid, and determine it as the current flowing through the shunt.

[0066] It is understandable that when the shunt is connected in series in the battery circuit, the current flowing through the shunt is the current flowing through the battery.

[0067] Exemplarily, the processor may determine whether the currents collected in the plurality of first sampling branches are effective according to a detection mechanism.

[0068] In one example, the detection mechanism can be to determine whether the calculated current value exceeds the maximum detection range of the ADC. If it is determined that the calculated current value exceeds the maximum detection range of the ADC, the current detected by the first sampling branch is determined to be an invalid current; otherwise, the current is determined to be valid.

[0069] In another example, the detection mechanism may be to determine whether a failure or error occurs in the ADC and / or the first signal conditioning module. If it is determined that neither the ADC nor the first signal conditioning module fails or has an error, then the current collected in the first sampling branch is determined to be a valid current; otherwise, if any one of the ADC and the first signal conditioning module fails or has an error, then the current collected in the first sampling branch is an invalid current.

[0070] It is understandable that in the above embodiments, the effective mechanism is only an exemplary description, and relevant technicians may also consider other factors as a detection mechanism to determine the effectiveness of each current among the multiple currents.

[0071] Further, it can be understood that if there are multiple first sampling branches in the battery management system, the processor can determine the current value of each first sampling branch, and can select any valid current among the currents corresponding to the multiple sampling branches as the current flowing through the shunt.

[0072] In the embodiment of the present application, the processor can determine whether the currents collected in the multiple first sampling circuits are valid, and select the valid current as the current flowing through the shunt, so that the processor has selection space, that is, the processor can select from multiple currents the current that can correctly characterize the current actually passing through the shunt, thereby improving the accuracy of the current detection function.

[0073] In some optional embodiments, if both the first current and the second current are valid and the difference between the first current and the second current is within a preset range, either the first current or the second current is selected and determined as the current flowing through the shunt; if both the first current and the second current are valid and the difference between the first current and the second current is not within the preset range, the larger of the first current and the second current is selected and determined as the current flowing through the shunt; if the first current is valid and the second current is not valid, the first current is selected and determined as the current flowing through the shunt; if the second current is valid and the first current is not valid, the second current is selected and determined as the current flowing through the shunt.

[0074] For example, referring to Table 1, the first current is I1, the second current is I2, and whether the difference between the first current and the second current is within the preset range is a rationality check. If the difference between the first current and the second current is within the preset range, the result of the rationality check is valid; otherwise, it is invalid. The current flowing through the shunt is determined as the current for overcurrent judgment.

[0075] Table 1

[0076]

[0077] Exemplarily, when the processor determines that there are both valid currents and invalid currents in the current values ​​corresponding to the calculated multiple first sampling branches, the processor may determine the valid current as the current flowing through the voltage divider.

[0078] Exemplarily, when the processor determines that the currents corresponding to the calculated multiple first sampling branches are all valid currents, the processor can calculate the difference between the valid currents. If the difference is within a preset range, any valid current can be determined as the current flowing through the voltage divider; if the difference is not within the preset range, the largest of the valid currents can be selected as the current flowing through the voltage divider.

[0079] In one example, when the processor determines that the currents corresponding to the calculated multiple first sampling branches are all valid currents, the current collected by the first sampling branch with higher precision of the first signal conditioning module and / or analog-to-digital converter can be selected as the current flowing through the voltage divider. It can be understood that after the circuit design is completed, the detection accuracy of each first sampling branch has been determined.

[0080] In one example, if the processor determines that the currents collected by the multiple first sampling branches are all invalid currents, the historically collected current can be obtained as the current currently flowing through the voltage divider. If the processor determines that the historically collected current is also an invalid current, an alarm message is sent to the user to indicate a fault.

[0081] It can be understood that the above embodiments can be used alone or in combination with multiple embodiments, and the order in which the multiple embodiments are used in combination is not limited herein.

[0082] In the embodiment of the present application, the processor can receive multiple first sampling circuits to collect multiple currents, and according to different situations of the multiple currents, can select the most appropriate current as the current flowing through the shunt, thereby improving the accuracy of the current detection function.

[0083] Furthermore, after determining the current flowing through the voltage divider, the processor can compare the current with a preset current threshold. When the current exceeds the current threshold, it can be determined that the current being charged and discharged exceeds the battery's capacity. At this point, the BMS needs to respond accordingly to protect the battery. For example, the BMS can send a power reduction request; or switch the current loop, etc. Therefore, in order to protect battery safety, a stable and reliable overcurrent post-fault handling function is essential.

[0084] In some optional embodiments, Figure 4 FIG. 2 shows a schematic diagram of the architecture of another battery management system provided in an embodiment of the present application. Figure 4 As shown, the battery management system 200 also includes a first driving module 230, which is connected to the processor 220. The processor 220 is also used to control the first driving module 230 to drive the target circuit to disconnect when it is determined that the current flowing through the shunt 100 is greater than the current threshold. The shunt 100 can be connected in series to the target circuit 300.

[0085] Exemplarily, the target circuit may include a battery circuit. Figure 5 FIG. 1 shows a schematic diagram of a connection between a diverter and a target circuit provided by an embodiment of the present application. Figure 5As shown, the target circuit 300 may include a power battery 1, a high-voltage load 2, and a total negative relay 3, and the shunt 100 may be connected between the negative electrode of the power battery and the high-voltage resistor. In addition, the battery management system 200 is connected to the shunt 100. When the processor in the battery management system determines that the current flowing through the shunt is greater than the current threshold, the relay in the target circuit can be controlled to disconnect by the first drive module. The first drive module can also control the circuit breaker, fuse or other device in the target circuit to disconnect the target circuit, which is not limited in this application.

[0086] In an embodiment of the present application, when the processor determines that the current flowing through the shunt is greater than the current threshold, the first drive module can be controlled to directly drive the target circuit to disconnect, thereby quickly cutting off the target circuit, that is, the charging and discharging circuit of the power battery can be quickly cut off, so that the power battery can quickly enter a safe state, which is beneficial to protecting the power battery.

[0087] In some optional embodiments, Figure 6 FIG. 2 shows a schematic diagram of the architecture of another battery management system provided by an embodiment of the present application. Figure 6 As shown, the battery management system 200 also includes a second sampling branch 240, the second sampling branch 240 includes a comparator 241 and a second driving module 242, the input end of the comparator 241 is connected to the first end and the second end of the shunt 100, the output end of the comparator 241 is connected to the second driving module 242, and the comparator 241 controls the second driving module 242 to drive the target circuit to disconnect when the voltage difference between the first end and the second end of the shunt 100 is greater than the threshold voltage. Wherein, the shunt is connected in series to the target circuit.

[0088] Exemplarily, the comparator is connected to the second sampling circuit, so the comparator can obtain the current value collected by the second sampling branch, which can be the current flowing through the shunt collected by the second sampling branch. Further, the comparator can calculate the voltage difference, i.e., the potential difference, across the alloy resistor in combination with the current collected by the second sampling branch and the resistance of the alloy resistor in the current meter. The potential difference is compared with the threshold voltage, and when the voltage difference is greater than the threshold voltage, the second drive module is controlled to drive the target circuit to disconnect.

[0089] In one example, when the comparator determines that the voltage difference is greater than the threshold voltage, it can output a first control signal, and through the first control signal, control the second drive module to control the main negative relay to disconnect, so that the charging and discharging circuit of the power battery is interrupted. If the comparator determines that the voltage difference is less than or equal to the threshold voltage, it can output a second control signal, and through the second control signal, control the second drive module to maintain the conductive state of the shunt and the target circuit.

[0090] In the embodiment of the present application, the voltage at both ends of the alloy resistor is reversely inferred by using the collected current and the resistance value in the shunt, so as to ensure that the alloy resistor is in a normal working state and is not damaged by excessive voltage, thereby avoiding the problem of reduced current detection accuracy caused by damage to the alloy resistor. In addition, the second signal conditioning module, the comparator and the second drive module in the second sampling branch are all analog circuits. Once it is determined that the collected current exceeds the preset threshold, the battery charging and discharging circuit can be quickly cut off by the second drive module, so that the power battery quickly enters a safe state without being limited by the running speed of the software in the processor.

[0091] In some optional embodiments, Figure 7 FIG. 2 shows a schematic diagram of the architecture of another battery management system provided by an embodiment of the present application. Figure 7 As shown, the second sampling branch 240 also includes a second signal conditioning module 243, and the input end of the comparator 241 is connected to the first end and the second end of the shunt 100 through the second signal conditioning module 243; the second signal conditioning module 243 is used to filter and / or amplify the signal. The signal is filtered and / or amplified by the second signal conditioning circuit, so that the comparator can receive high-quality signals, improve the accuracy of the comparator, and thus better protect the dynamic point battery.

[0092] To better understand the beneficial effects of the embodiments of the present application, please refer to Figure 8 .

[0093] Figure 8 A schematic diagram of a current detection structure of a comparative example is shown. Figure 8 As shown, the potential difference across the alloy resistor 110 can be introduced into the BMS 200 through a connector and / or a wiring harness. Among them, the BMS may include a first signal conditioning module 211, an analog-to-digital converter 212, a processor 220, and a first drive module 230, wherein the first drive circuit includes an actuator drive circuit. Among them, the signal conditioning circuit can perform corresponding signal conditioning on both ends of the alloy resistor 110, so that the conditioned signal quality is better. The MCU can be used to calculate the voltage difference across the alloy resistor, and determine the current flowing through the shunt based on the voltage difference, so as to achieve the effect of current detection. Further, after the MCU determines the current flowing through the shunt, the current value can be compared with a preset safety threshold to determine whether to enable the actuator drive circuit. The actuator drive circuit is used to control whether to pop open a relay or switch (pyrofuse). Through the actuator circuit, it is possible to cut off the charging and discharging circuit of the power battery, thereby protecting the battery.

[0094] The battery management system in the embodiment of the present application is provided with multiple first sampling branches. In this way, when one or some of the first sampling branches fail, other first sampling branches can be used to collect signals, thereby realizing a redundant design. It can effectively prevent the failure of the current monitoring function caused by the failure of one or some of the first sampling branches, thereby improving the reliability of the current detection function.

[0095] Based on the same inventive concept, the embodiment of the present application also provides a battery system, including a battery and a battery management system in any of the above embodiments. It can be understood that the battery system has the beneficial effects of the battery management system provided in the embodiment of the present application, and the specific description of the battery management system in the above embodiments can be referred to, and this embodiment will not be repeated here.

[0096] Based on the same inventive concept, the present application also provides an electric device. The electric device includes a battery system, and the battery system includes the battery management system in any of the above embodiments. It can be understood that the electric device has the beneficial effects of the battery management system provided in the embodiments of the present application. For details, please refer to the specific description of the battery management system in the above embodiments, which will not be repeated in this embodiment.

[0097] It should be noted that, in the above embodiments, the resistor is represented by a single resistor. In other embodiments, the resistor may also be an integration of series, parallel or hybrid resistors. In addition, in the above embodiments, the capacitor is represented by a single capacitor. In other embodiments, the capacitor may also be an integration of series, parallel or hybrid capacitors. The specific parameters of each device may be set according to actual needs, and this application does not limit this.

[0098] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application may be combined with each other.

[0099] Although the present application has been described with reference to preferred embodiments, various modifications may be made thereto and parts thereof may be replaced with equivalents without departing from the scope of the present application. In particular, the various technical features mentioned in the various embodiments may be combined in any manner as long as there is no structural conflict. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A battery management system, characterized in that: It comprises n first sampling branches, each of which is connected to a first end and a second end of a current divider, and is used to collect signals from the first end and the second end of the current divider, wherein n is an integer greater than 1; The battery management system also includes a processor, which is connected to n first sampling branches. The processor is used to determine the current flowing through the shunt based on the signals collected by the n first sampling branches. The processor is also used to: for any two of the first sampling branches, determine that the current collected by one of the first sampling branches is the first current, determine that the current collected by the other first sampling branch is the second current, and select the one of the first current and the second current that is valid to determine it as the current flowing through the shunt.

2. The battery management system according to claim 1, characterized in that: Different first sampling branches are connected to the first end of the shunt through different first signal lines, and different first sampling branches are connected to the second end of the shunt through different second signal lines.

3. The battery management system according to claim 1 or 2, characterized in that: The first sampling branch includes a first signal conditioning module and an analog-to-digital converter, the input end of the first signal conditioning module is connected to the first end and the second end of the current divider, and the output end of the first signal conditioning module is connected to the input end of the analog-to-digital converter; The first signal conditioning module is used to filter and / or amplify the signal; The analog-to-digital converter is used to convert an analog signal into a digital signal.

4. The battery management system according to claim 1, characterized in that: The processor is configured to: if both the first current and the second current are valid and the difference between the first current and the second current is within a preset range, select any one of the first current and the second current as the current flowing through the shunt; If both the first current and the second current are valid, and the difference between the first current and the second current is not within the preset range, selecting the larger one of the first current and the second current as the current flowing through the shunt; If the first current is valid and the second current is not valid, selecting the first current as the current flowing through the shunt; If the second current is valid and the first current is not valid, the second current is selected to be determined as the current flowing through the shunt.

5. The battery management system according to claim 1 or 2, characterized in that: The shunt is connected in series to the target circuit, and the battery management system also includes a first drive module, which is connected to the processor. The processor is also used to control the first drive module to drive the target circuit to disconnect when it is determined that the current flowing through the shunt is greater than a current threshold.

6. The battery management system according to claim 1 or 2, characterized in that: The shunt is connected in series to the target circuit, and the battery management system also includes a second sampling branch, which includes a comparator and a second driving module. The input end of the comparator is connected to the first end and the second end of the shunt, and the output end of the comparator is connected to the second driving module. When the voltage difference between the first end and the second end of the shunt is greater than a threshold voltage, the comparator controls the second driving module to drive the target circuit to disconnect.

7. The battery management system according to claim 6, characterized in that: The second sampling branch further includes a second signal conditioning module, and the input end of the comparator is connected to the first end and the second end of the shunt through the second signal conditioning module; The second signal conditioning module is used to filter and / or amplify the signal.

8. A battery system, characterized in that: The invention comprises a battery and a battery management system as claimed in any one of claims 1 to 7.

9. An electrical device, characterized in that: Comprising the battery system as claimed in claim 8.

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