Battery management system, battery device and electric device

Abstract

The utility model discloses a battery management system, a battery device and a power utilization device. The battery management system comprises a gating circuit, a voltage sampling circuit and a processor. The gating circuit is connected with n to-be-sampled points of the power supply branch, the gating circuit is connected with the voltage sampling circuit, the gating circuit is configured to communicate any two to-be-sampled points with the voltage sampling circuit, the power supply branch is used for connecting a battery, and n is an integer greater than 2; the voltage sampling circuit is configured to collect voltages of two to-be-sampled points communicated with the voltage sampling circuit; the processor is electrically connected with the voltage sampling circuit, and the processor is configured to determine the resistance between any two sampling points according to the voltages of any two sampling points to be sampled and the currents flowing through the two sampling points to be sampled, which are acquired by the voltage sampling circuit. According to the embodiment of the invention, the cost can be reduced.

Description

Technical Field

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

[0002] With the rapid development of new energy vehicles such as new energy cars, the emergence of new energy vehicles has played a huge role in promoting social development and environmental protection.

[0003] In order to ensure that the battery can be charged and discharged safely and stably, the battery management system (BMS) plays a vital role. Voltage detection is the basic function of BMS, and how to optimize the structural design of BMS for voltage detection is a technical problem that technicians in this field are committed to solving. Utility Model Content

[0004] The present application provides a battery management system, a battery device and an electric device, which can achieve cost reduction.

[0005] In a first aspect, the present application provides a battery management system, comprising a gating circuit, a voltage sampling circuit and a processor; the gating circuit is connected to n points to be sampled of a power supply branch, and the gating circuit is connected to the voltage sampling circuit, the gating circuit is configured to connect any two points to be sampled to the voltage sampling circuit, the power supply branch is used to connect the battery, and n is an integer greater than 2; the voltage sampling circuit is configured to collect voltages of two points to be sampled connected thereto; the processor is electrically connected to the voltage sampling circuit, and the processor is configured to: determine the resistance between any two points to be sampled based on the voltages of any two points to be sampled collected by the voltage sampling circuit and the current flowing through the two points to be sampled.

[0006] According to the battery management system provided by the embodiment of the present application, by setting a gating circuit and a voltage sampling circuit, the gating circuit is configured to connect any two points to be sampled with the voltage sampling circuit, and the voltage sampling circuit is configured to collect the voltages of the two points to be sampled connected thereto, and the voltage collection of n points to be sampled can be realized through one voltage sampling circuit, which can reduce the number of voltage sampling circuits, thereby realizing cost reduction while realizing the collection of voltages of multiple points to be sampled; and, the impedance on the power supply branch outside the battery module can be detected, which is conducive to timely discovering sampling points with higher impedance and preventing problems before they occur.

[0007] In a possible implementation manner of the first aspect, the power supply branch includes a first switch device, a first end of the first switch device is used to connect to the battery, and a second end of the first switch device is used to connect to at least one of a charging interface and a load;

[0008] The n points to be sampled include a first point to be sampled and a second point to be sampled, the first point to be sampled is located on a connection path between a first end of a first switching device and a battery, the second point to be sampled is located on a connection path between a second end of the first switching device and a target device, and the second point to be sampled is connected to a gating circuit via a second switching device.

[0009] In the embodiment of the present application, the second point to be sampled is connected to the gating circuit via a second switching device, and the second switching device can be used to prevent excessive voltage changes at the second point to be sampled from acting on the gating circuit, thereby preventing the gating circuit from being damaged by a large voltage.

[0010] In a possible implementation of the first aspect, when the first switch device is in a closed state and when it is necessary to detect a voltage at a second point to be sampled connected to the second switch device, the second switch device is configured to be closed.

[0011] When the second switch device is closed, the second point to be sampled is connected to the gating circuit. Further, the gating circuit connects the second point to be sampled to the voltage sampling circuit to ensure that the voltage sampling circuit can collect the voltage of the second point to be sampled.

[0012] In a possible implementation manner of the first aspect, the second switching device is configured to be turned off before the first switching device is turned off.

[0013] In an embodiment of the present application, the second switching device is disconnected before the first switching device is disconnected, so that after the first switching device is switched from a closed state to an open state, the second switching device is already in an open state, and the excessive voltage at the second sampling point will not act on the selection circuit through the second switching device, thereby preventing the selection circuit from being damaged by the large voltage.

[0014] In a possible implementation manner of the first aspect, the gating circuit is configured to connect any two adjacent points to be sampled to the voltage sampling circuit at least once in a sampling period.

[0015] In the embodiment of the present application, in one sampling cycle, the gating circuit traverses all adjacent points to be sampled, so that the voltage of any adjacent points to be sampled can be monitored, and further the impedance between any adjacent points to be sampled can be monitored.

[0016] In a possible implementation of the first aspect, the gating circuit is configured to: connect any two points to be sampled with the voltage sampling circuit during the charging stage of the battery; and the voltage sampling circuit is configured to collect voltages of the two points to be sampled connected thereto during the charging stage of the battery.

[0017] During the battery charging stage, the current on the power supply branch is relatively stable. At this time, the current sensor can accurately measure the current flowing through the power supply branch, that is, the current flowing through each sampling point. At the same time, the gating circuit connects any two sampling points to the voltage sampling circuit, and the voltage sampling circuit collects the voltage of the two sampling points connected to it. By selecting a relatively stable current working condition for impedance measurement, the accuracy of impedance detection can be guaranteed.

[0018] In a possible implementation of the first aspect, the processor is further configured to: output alarm information when the resistance between two points to be sampled exceeds a corresponding resistance threshold.

[0019] According to an embodiment of the present application, the processor is configured to sound an alarm and report a corresponding fault when the resistance between the points to be sampled exceeds a corresponding resistance threshold. In this way, the user can be reminded to promptly repair or replace the problematic device, thereby preventing the negative impact on the performance and safety of the battery caused by the increase in impedance on the power supply branch.

[0020] In a possible implementation manner of the first aspect, the power supply branch includes a plurality of connecting plates connected in series, and the points to be sampled include connection points between the connecting plates connected to each other.

[0021] In the embodiment of the present application, the connection points between the interconnected connecting pieces are used as sampling points, and the voltage of the sampling points is collected, so that the voltage of the connection points between the connecting pieces can be monitored. Furthermore, according to the voltage and current of the sampling points, the impedance between the connection points can be monitored, and a fault is reported in time after the impedance exceeds the specification, thereby preventing the negative impact caused by excessive impedance.

[0022] In a possible implementation of the first aspect, a gasket is connected between the interconnected connecting sheets, the sampling point is connected to the gating circuit via a sampling line, and one end of the sampling line is pressed between the gasket and the connecting sheet.

[0023] According to the signal sampling circuit 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.

[0024] Based on the same technical concept, in a second aspect, an embodiment of the present application provides a battery device, including a battery and a battery management system as described in any embodiment of the first aspect.

[0025] Based on the same technical concept, in a third aspect, an embodiment of the present application provides an electrical device, comprising a battery device as described in the embodiment of the second aspect.

[0026] 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

[0027] The features, advantages and technical effects of exemplary embodiments of the present application will be described below with reference to the accompanying drawings.

[0028] Figure 1 This is a schematic diagram of the structure of a battery management system according to an embodiment of the present application;

[0029] Figure 2 This is a schematic structural diagram of a battery management system according to another embodiment of the present application;

[0030] Figure 3 This is a schematic structural diagram of a battery management system according to another embodiment of the present application;

[0031] Figure 4 This is a schematic structural diagram of a battery management system according to another embodiment of the present application;

[0032] Figure 5 A connection diagram of a sampling line according to an embodiment of the present application. DETAILED DESCRIPTION

[0033] 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.

[0034] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings 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.

[0035] 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.

[0036] The functions of BMS may include monitoring voltage, current, temperature, detecting the status of main circuit relays, etc. With the continuous development of new energy vehicle technology and the expansion of related businesses, BMS also needs to add related functions to match it, such as detecting the voltage of multiple sampling points on the high-voltage circuit, so as to judge the status of the device based on the voltage of the sampling points, etc. How to reduce the cost of the voltage detection solution for multiple sampling points on the high-voltage circuit is a technical problem faced by relevant technicians.

[0037] The embodiments of the present application provide a battery management system, a battery device and an electric device. The battery management system, the battery device and the electric device provided in the embodiments of the present application will be described in detail below with reference to the accompanying drawings.

[0038] The following first introduces the battery management system provided by the application embodiment.

[0039] Figure 1 FIG. 1 is a schematic diagram of a battery management system according to an embodiment of the present application. Figure 1 As shown, the battery management system 10 provided in the embodiment of the application includes a gating circuit 11 and a voltage sampling circuit 12 .

[0040] The gating circuit 11 is connected to n points to be sampled (P1-Pn) of the power supply branch 20, and the gating circuit 11 is connected to the voltage sampling circuit 12. The gating circuit 11 is configured to connect any two points to be sampled to the voltage sampling circuit 12. The voltage sampling circuit 12 is configured to collect the voltages of the two points to be sampled connected thereto.

[0041] The power supply branch 20 is used to connect to the battery 30 , and n is an integer greater than 2.

[0042] Exemplarily, one end of the power supply branch 20 is used to connect the positive electrode or the negative electrode of the battery 30, and the other end of the power supply branch 20 is used to connect at least one of the charging interface and the load. The power supply branch 20 can be used as a branch for the battery 30 to supply power to the load, and / or, the power supply branch 20 can be used as a branch for the charging interface to charge the battery 30. The power supply branch 20 can also be called a high-voltage branch.

[0043] As an example, the power supply branch 20 is used to connect the negative electrode of the battery 30. In this case, the power supply branch 20 can be understood as a high-voltage branch to which the negative electrode of the battery 30 is connected.

[0044] As another example, the power supply branch 20 is used to connect the positive electrode of the battery 30. In this case, the power supply branch 20 can be understood as a high-voltage branch to which the positive electrode of the battery 30 is connected.

[0045] The power supply branch 20 includes n points to be sampled, which are connected in series. It can be understood that the n points to be sampled are nodes at different positions on the power supply branch 20.

[0046] Exemplarily, the gating circuit 11 includes n input terminals, and the n input terminals of the gating circuit 11 are connected one-to-one with the n points to be sampled (P1-Pn) of the power supply branch 20. The gating circuit 11 includes two output terminals, and the two output terminals of the gating circuit 11 are connected one-to-one with the two input terminals of the voltage sampling circuit 12. The two input terminals of the voltage sampling circuit 12 are respectively used to collect the voltages of the points to be sampled connected thereto.

[0047] It can be understood that the gating circuit 11 is configured to connect any two points to be sampled with the voltage sampling circuit 12, including: the gating circuit 11 is configured to be able to connect the i-th point to be sampled and the j-th sampling point with the voltage sampling circuit 12, i≠j, and i and j are any one of 1~n.

[0048] For example, when the selection circuit 11 is configured to connect the first point to be sampled P1 and the second point to be sampled P2 to the voltage sampling circuit 12 , the voltage sampling circuit 12 can collect the voltages of the first point to be sampled P1 and the second point to be sampled P2 .

[0049] For another example, when the selection circuit 11 is configured to connect the second point to be sampled P2 and the third point to be sampled P3 to the voltage sampling circuit 12, the voltage sampling circuit 12 can collect the voltages of the second point to be sampled P2 and the third point to be sampled P3.

[0050] For another example, when the gating circuit 11 is configured to connect the third point to be sampled P3 and the fourth point to be sampled P4 to the voltage sampling circuit 12, the voltage sampling circuit 12 can collect the voltages of the third point to be sampled P3 and the fourth point to be sampled P4.

[0051] It is understandable that the battery management system provided in the embodiment of the present application can collect the voltages of all n points to be sampled through the cooperation of the selection circuit 11 and the voltage sampling circuit. That is to say, by setting up a voltage sampling circuit, the voltage of each point to be sampled can be collected.

[0052] According to the battery management system provided by the embodiment of the present application, by setting a gating circuit and a voltage sampling circuit, the gating circuit is configured to connect any two points to be sampled with the voltage sampling circuit, and the voltage sampling circuit is configured to collect the voltages of the two points to be sampled connected thereto, and the voltage collection of n points to be sampled can be realized through one voltage sampling circuit, which can reduce the number of voltage sampling circuits, thereby realizing cost reduction while realizing the collection of voltages of multiple points to be sampled.

[0053] It should be noted that the specific structure of the gating circuit is not limited in the embodiment of the present application, as long as it can connect any two points to be sampled with the voltage sampling circuit at the same time. In addition, the specific structure of the voltage sampling circuit is not limited in the embodiment of the present application, as long as it can collect the voltage of the point to be sampled.

[0054] The inventors have found that in order to ensure that the vehicle's power battery can be charged and discharged safely and stably, it is necessary to monitor the impedance of the high-voltage branch connected to the positive and / or negative electrodes of the battery. If the impedance is too large, when the battery is charged and discharged with a large current, the high-voltage point with large impedance will generate more heat, which will increase the battery temperature and affect the battery charging and discharging performance, or burn the high-voltage branch and affect safety.

[0055] Figure 2 FIG. 1 is a schematic diagram of a battery management system according to another embodiment of the present application. Figure 2 As shown, the battery management system 10 further includes a processor 13, which is electrically connected to the voltage sampling circuit 12. The processor 13 is configured to determine the resistance between two points to be sampled according to the voltage difference between any two points to be sampled collected by the voltage sampling circuit 12 and the current flowing through the two points to be sampled.

[0056] The n points to be sampled (P1-Pn) on the power supply branch 20 are connected in series, and the currents flowing through two points to be sampled are equal.

[0057] Exemplarily, the battery management system may include a current sensor (not shown in the figure), which is used to collect the current of the power supply branch 20, that is, the current flowing through any two points to be sampled. For example, the current sensor may include a shunt or a Hall current sensor.

[0058] As an example, the voltage sampling circuit 12 is configured to collect the voltage difference ∆V of two points to be sampled connected thereto. In this way, the processor 13 can directly obtain the voltage difference ∆V of the two points to be sampled collected by the voltage sampling circuit 12, and according to the current I flowing through the two points to be sampled, according to the formula R=∆V / I, the resistance between the two points to be sampled can be obtained.

[0059] Exemplarily, the voltage sampling circuit may use a high-precision voltage sampling chip that can sample small voltages, thereby ensuring the accuracy of voltage sampling.

[0060] For example, when the gating circuit 11 is configured to connect the first point to be sampled P1 and the second point to be sampled P2 to the voltage sampling circuit 12, the voltage sampling circuit 12 is configured to collect the voltage difference ∆V12 between the first point to be sampled P1 and the second point to be sampled P2, and the current flowing through the first point to be sampled P1 and the second point to be sampled P2 is recorded as I12. The processor 13 is configured to obtain the resistance R12 between the first point to be sampled P1 and the second point to be sampled P2 according to the formula R=∆V12 / I12.

[0061] For another example, when the gating circuit 11 is configured to connect the second point to be sampled P2 and the third point to be sampled P3 to the voltage sampling circuit 12, the voltage sampling circuit 12 is configured to collect the voltage difference ∆V23 between the second point to be sampled P2 and the third point to be sampled P3, the current flowing through the second point to be sampled P2 and the third point to be sampled P3 is recorded as I23, and the processor 13 is configured to obtain the resistance R23 between the second point to be sampled P2 and the third point to be sampled P3 according to the formula R=∆V23 / I23. And so on, no more examples are given here.

[0062] The power supply branch 20 is used to connect the battery 30, which can also be called a battery module. The power supply branch 20 is a circuit outside the battery module. According to the embodiment of the present application, the impedance on the power supply branch 20 outside the battery module can be detected, which is conducive to timely discovering sampling points with higher impedance and preventing problems before they occur.

[0063] Figure 3 FIG. 1 is a schematic diagram of a battery management system according to another embodiment of the present application. Figure 3 As shown, the power supply branch 20 includes a first switch device K1, a first end of the first switch device K1 is used to connect to the battery 30, and a second end of the first switch device K1 is used to connect to a target device (not shown in the figure), and the target device includes at least one of a charging interface and a load. The n points to be sampled include a first point to be sampled and a second point to be sampled, the first point to be sampled is located on the connection path between the first end of the first switch device K1 and the battery 30, the second point to be sampled is located on the connection path between the second end of the first switch device K1 and the target device, and the second point to be sampled is connected to the gating circuit 11 through the second switch device K2.

[0064] For example, the first switch device K1 includes but is not limited to a relay. The second switch device K2 includes but is not limited to a reed switch, a relay, an optical coupler, and other switch-type devices that function as switches.

[0065] The first end of the first switch device K1 is connected to the battery 30, and the second end of the first switch device K1 is used to connect to the charging interface and / or the load. The first point to be sampled connected to the first end of the first switch device K1 can be called the point to be sampled inside the first switch device K1, and the second point to be sampled connected to the second end of the first switch device K1 can be called the point to be sampled outside the first switch device K1.

[0066] For example, Figure 3 In the example, the first points to be sampled include the first point to be sampled P1, the second point to be sampled P2, and the third point to be sampled P3; the second points to be sampled include the nth point to be sampled Pn.

[0067] The first point to be sampled is directly connected to the gating circuit 11 through the sampling line, and the first point to be sampled is always connected to the gating circuit 11. The second point to be sampled is connected to the gating circuit 11 through the second switch device K2. When the second switch device K2 is closed, the second point to be sampled is connected to the gating circuit 11; when the second switch device K2 is opened, the second point to be sampled is disconnected from the gating circuit 11, and at this time, the voltage of the second point to be sampled does not act on the gating circuit 11.

[0068] It should be noted that, when the second point to be sampled includes multiple points to be sampled, there are also multiple second switch devices K2, and the multiple second switch devices K2 are connected to the multiple second points to be sampled in a one-to-one correspondence, and different second points to be sampled are connected to different input terminals of the selection circuit 11 through different second switch devices K2.

[0069] It is understandable that the first point to be sampled is not connected to the battery 30 through the first switch device K1, and the second point to be sampled is connected to the battery 30 through the first switch device K1. When the voltage of the battery 30 remains unchanged, the voltage of the first point to be sampled will not change whether the first switch device K1 is in an open state or a closed state. Therefore, the first point to be sampled will not cause an excessive voltage impact on the gating circuit 11. When the first switch device K1 is closed, the voltage of the second point to be sampled is approximately equal to the voltage of the battery 30. When the first switch device K1 is disconnected, the voltage of the second point to be sampled will drop significantly. Therefore, the second point to be sampled may cause an excessive voltage impact on the gating circuit 11, which may cause the gating circuit 11 to be damaged by the large voltage.

[0070] In the embodiment of the present application, the second point to be sampled is connected to the gating circuit via a second switching device, and the second switching device can be used to prevent excessive voltage changes at the second point to be sampled from acting on the gating circuit, thereby preventing the gating circuit from being damaged by a large voltage.

[0071] In some embodiments, Figure 3As shown, when the first switch device K1 is in a closed state and the voltage of the second sampling point connected to the second switch device K2 needs to be detected, the second switch device K2 is configured to be closed.

[0072] When the battery management system is just powered on, the default state of the second switch device K2 is the open state. When the impedance measurement of the corresponding channel is performed and the first switch device K1 is in the closed state, the second switch device K2 may be allowed to be closed.

[0073] When the second switch device K2 is closed, the second point to be sampled is connected to the gating circuit 11. Further, the gating circuit 11 connects the second point to be sampled to the voltage sampling circuit 12 to ensure that the voltage sampling circuit 12 can collect the voltage of the second point to be sampled.

[0074] In some embodiments, Figure 3 As shown, the second switching device K2 is configured to be turned off before the first switching device K1 is turned off.

[0075] When the first switch device K1 switches from a closed state to an open state, the voltage at the second point to be sampled will change significantly. If the second switch device K2 remains closed after the first switch device K1 switches from a closed state to an open state, the excessive voltage at the second point to be sampled will act on the selection circuit 11 through the second switch device K2, causing the selection circuit to be damaged by the large voltage.

[0076] In the embodiment of the present application, the second switch device K2 is disconnected before the first switch device K1 is disconnected, so that after the first switch device K1 is switched from a closed state to an open state, the second switch device K2 is already in an open state, and the excessive voltage at the second sampling point will not act on the selection circuit 11 through the second switch device K2, thereby preventing the selection circuit from being damaged by a large voltage.

[0077] In some embodiments, the gating circuit is configured to connect any two points to be sampled to the voltage sampling circuit at least once in a sampling cycle. Here, any two points to be sampled may be any two adjacent points to be sampled, or any two points to be sampled may be any two non-adjacent points to be sampled.

[0078] For example, any two points to be sampled include any two adjacent points to be sampled. In a sampling period, the gating circuit is configured as follows:

[0079] First, the first point to be sampled P1 and the second point to be sampled P2 are connected to the voltage sampling circuit 12, so that the voltage sampling circuit 12 can collect the voltage of the first point to be sampled P1 and the second point to be sampled P2 or the voltage difference between the two;

[0080] Next, the second point to be sampled P2 and the third point to be sampled P3 are connected to the voltage sampling circuit 12, so that the voltage sampling circuit 12 can collect the voltage of the second point to be sampled P2 and the third point to be sampled P3 or the voltage difference between the two;

[0081] Next, the third point to be sampled P3 and the fourth point to be sampled P4 are connected to the voltage sampling circuit 12, so that the voltage sampling circuit 12 can collect the voltage of the third point to be sampled P3 and the fourth point to be sampled P4 or the voltage difference between the two;

[0082] By analogy, finally, the n-1th point to be sampled and the nth point to be sampled Pn are connected to the voltage sampling circuit 12, so that the voltage sampling circuit 12 can collect the voltage of the n-1th point to be sampled and the nth point to be sampled Pn or the voltage difference between the two.

[0083] It should be noted that, in a sampling cycle, there is no limitation on the order of conducting between the points to be sampled and the voltage sampling circuit. If some points to be sampled have a relatively large impact on the safe and stable operation of the battery, the gating circuit 11 may be configured to: in a sampling cycle, preferentially connect the points to be sampled with a large impact to the voltage sampling circuit at least once, and / or, in a sampling cycle, connect the points to be sampled with a large impact to the voltage sampling circuit multiple times.

[0084] In the embodiment of the present application, in one sampling cycle, the gating circuit traverses all adjacent points to be sampled, so that the voltage of any adjacent points to be sampled can be monitored, and further the impedance between any adjacent points to be sampled can be monitored.

[0085] As mentioned above, the processor needs to monitor the resistance between two points to be sampled based on the current flowing through the points to be sampled. If the current is unstable, the accuracy of the resistance monitoring will be affected. When the battery supplies power to the load, the power of the load may change, resulting in unstable current on the power supply branch.

[0086] In some embodiments, the gating circuit is configured to: connect any two points to be sampled to the voltage sampling circuit during the battery charging stage; the voltage sampling circuit is configured to collect voltages of the two points to be sampled connected thereto during the battery charging stage.

[0087] During the battery charging stage, the current on the power supply branch is relatively stable. At this time, the current sensor can accurately measure the current flowing through the power supply branch, that is, the current flowing through each sampling point. At the same time, the gating circuit connects any two sampling points to the voltage sampling circuit, and the voltage sampling circuit collects the voltage of the two sampling points connected to it. By selecting a relatively stable current working condition for impedance measurement, the accuracy of impedance detection can be guaranteed.

[0088] Exemplarily, the battery charging stage includes an alternating current (AC) charging stage, or a low-current direct current (DC) charging stage.

[0089] In some embodiments, the processor is further configured to: output an alarm message when the resistance between two points to be sampled is greater than a corresponding resistance threshold.

[0090] Exemplarily, the resistance threshold may be a preset minimum resistance value to ensure that the battery can be charged and discharged safely and stably.

[0091] For example, after determining the resistance R12 between the first point to be sampled P1 and the second point to be sampled P2, the processor may compare the resistance R12 with the resistance threshold R1' corresponding to the first point to be sampled P1 and the second point to be sampled P2. When R12 exceeds R1', the processor issues an alarm, reporting that there is a fault in which the resistance between the first point to be sampled P1 and the second point to be sampled P2 is too large.

[0092] For another example, after determining the resistance R23 between the second point to be sampled P2 and the third point to be sampled P3, the processor may compare the resistance R23 with the resistance threshold R2' corresponding to the second point to be sampled P2 and the third point to be sampled P3. When R23 exceeds R2', the processor issues an alarm, reporting that there is a fault that the resistance between the second point to be sampled P2 and the third point to be sampled P3 is too large. And so on, no more examples are given here.

[0093] It should be noted that the n points to be sampled are connection points at different positions on the power supply branch, and the resistance thresholds corresponding to different sampling points can be determined according to actual conditions, and the resistance thresholds corresponding to different sampling points can be different. For example, the resistance threshold R1' is different from the resistance threshold R2'.

[0094] According to an embodiment of the present application, the processor is configured to sound an alarm and report a corresponding fault when the resistance between the points to be sampled exceeds a corresponding resistance threshold. In this way, the user can be reminded to promptly repair or replace the problematic device, thereby preventing the negative impact on the performance and safety of the battery caused by the increase in impedance on the power supply branch.

[0095] In some embodiments, Figure 4 As shown, the power supply branch 20 includes a plurality of connecting pieces 21 connected in series, and the points to be sampled include connection points between the connecting pieces 21 connected to each other.

[0096] Figure 4 The hollow circles in the figure represent the connection points between the interconnected connecting pieces 21. Exemplarily, the connecting piece 21 is a metal plate that plays a connecting role in the power supply branch 20. The connecting piece 21 is used to connect the devices on the power supply branch 20 and to connect the power supply branch 20 to the battery 30. For example, Figure 4 Also shown are a shunt 23 and a first switch device K1 in the power supply branch 20. A connecting piece 21 is connected between a first end of the shunt 23 and a first end of the first switch device K1, a connecting piece 21 is connected between a second end of the shunt 23 and a battery 30, and a connecting piece 21 is connected to the second end of the first switch device K1.

[0097] The connecting sheet 21 may be called a palladium sheet, and the material of the connecting sheet 21 is not limited to copper bar, aluminum bar, etc.

[0098] At least one end of the connecting piece 21 includes a connecting point. For example, when the connecting pieces 21 are connected by bolts, the connecting point may be referred to as a bolt locking point.

[0099] The inventors have found that the impedance exceeding the specification in the power supply branch 20 mainly occurs at the connection and locking points of each device (i.e., the connection points of the connecting pieces), such as the bolt locking points between copper bars, the bolt locking points between copper bars and current sensors (such as shunts), the bolt locking points between copper bars and relays (such as the first switching device), and the bolt locking points between copper bars and fuses.

[0100] Therefore, it is very important to monitor the impedance of each locking point in the power supply branch.

[0101] In the embodiment of the present application, the connection points between the interconnected connecting pieces are used as sampling points, and the voltage of the sampling points is collected, so that the voltage of the connection points between the connecting pieces can be monitored. Furthermore, according to the voltage and current of the sampling points, the impedance between the connection points can be monitored, and a fault is reported in time after the impedance exceeds the specification, thereby preventing the negative impact caused by excessive impedance.

[0102] Figure 5 FIG. 1 is a schematic diagram of the connection of sampling lines in a battery management system according to an embodiment of the present application. Figure 5 As shown, a gasket 22 is connected between the interconnected connecting pieces 21 , and the sampling point is connected to the gating circuit through a sampling line 14 , and one end of the sampling line 14 is pressed between the gasket 22 and the connecting piece 21 .

[0103] For example, when the connection between the connecting pieces 21 is achieved by bolts, a gasket 22 is usually added, and one end of the sampling line 14 is pressed between the gasket 22 and the connecting piece 21, so that the connection between the sampling line 14 and the bolt locking point of the connecting piece 21 can be achieved, without welding, and it is easy to disassemble.

[0104] Based on the same technical concept, the embodiment of the present application also provides a battery device, including a battery and a battery management system in any of the above embodiments. It can be understood that the battery device has the beneficial effects of the battery management system provided in the embodiment 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.

[0105] Based on the same technical concept, the present application also provides an electric device. The electric device includes a battery device, and the battery device includes a 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.

[0106] 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.

[0107] 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.

[0108] 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 includes a gating circuit, a voltage sampling circuit and a processor; The gating circuit is connected to n points to be sampled of the power supply branch, and the gating circuit is connected to the voltage sampling circuit, the gating circuit is configured to connect any two points to be sampled with the voltage sampling circuit, the power supply branch is used to connect a battery, and n is an integer greater than 2; The voltage sampling circuit is configured to collect voltages of two points to be sampled that are connected to it; The processor is electrically connected to the voltage sampling circuit, and is configured to determine the resistance between any two points to be sampled according to the voltages of any two points to be sampled collected by the voltage sampling circuit and the currents flowing through the two points to be sampled.

2. The battery management system according to claim 1, characterized in that: The power supply branch includes a first switch device, a first end of the first switch device is used to connect to a battery, and a second end of the first switch device is used to connect to a target device, and the target device includes at least one of a charging interface and a load; The n points to be sampled include a first point to be sampled and a second point to be sampled, the first point to be sampled is located on a connection path between a first end of the first switching device and the battery, the second point to be sampled is located on a connection path between a second end of the first switching device and the target device, and the second point to be sampled is connected to the gating circuit via a second switching device.

3. The battery management system according to claim 2, characterized in that: When the first switching device is in a closed state and when it is necessary to detect the voltage of the second point to be sampled connected to the second switching device, the second switching device is configured to be closed.

4. The battery management system according to claim 2, characterized in that: The second switching device is configured to open before the first switching device opens.

5. The battery management system according to claim 1, characterized in that: The gating circuit is configured to connect any two adjacent points to be sampled with the voltage sampling circuit at least once in a sampling cycle.

6. The battery management system according to claim 1, characterized in that: The gating circuit is configured to: connect any two points to be sampled with the voltage sampling circuit during the charging stage of the battery; and the voltage sampling circuit is configured to collect voltages of the two points to be sampled connected thereto during the charging stage of the battery.

7. The battery management system according to claim 1, characterized in that: The processor is further configured to output alarm information when the resistance between the two points to be sampled exceeds a corresponding resistance threshold.

8. The battery management system according to claim 1, characterized in that: The power supply branch includes a plurality of connecting plates connected in series, and the points to be sampled include connecting points between the connecting plates connected to each other.

9. The battery management system according to claim 8, characterized in that: A gasket is connected between the interconnected connecting sheets, the point to be sampled is connected to the gating circuit via a sampling line, and one end of the sampling line is pressed between the gasket and the connecting sheet.

10. A battery device, characterized in that: The invention comprises a battery and a battery management system as claimed in any one of claims 1 to 9.

11. An electrical device, characterized in that: Comprising the battery device as claimed in claim 10.

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