Battery Management System

Abstract

The present application provides a battery management system, including a current limiting circuit having a first controllable switch and a current limiting resistor, a main circuit having a second controllable switch, and a battery management system control unit, wherein the current limiting circuit is connected in parallel with the main circuit and connected in series between the battery pack and the load, and the battery management system control unit is connected to the first controllable switch and the second controllable switch for controlling the on or off thereof. When the battery management system is in sleep mode, the first controllable switch is controlled to be on and the second controllable switch is controlled to be off, so that the battery pack supplies power to the load based on the current limiting circuit. The battery management system of the present application adds a current limiting circuit having a current limiting resistor connected in parallel with the main circuit, so that when the battery management system is in sleep mode, the load can be supplied with power based on the current limiting circuit, thereby effectively reducing the current consumption in sleep mode, thereby reducing the frequency of users recharging the battery pack and improving the user experience.

Description

Technical Field

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

[0002] With the development of the automotive industry, new energy vehicles are becoming increasingly common in daily life. Most new energy vehicles use lithium-ion battery packs as starting batteries. These packs consist of a battery pack and a battery management system (BMS). The BMS manages the battery pack to power the vehicle's loads.

[0003] However, when the battery management system is not activated for a period of time, it will enter sleep mode. However, at this time, the on-board loads still need to be powered continuously, so a main circuit for powering the on-board loads can be added between the battery pack and the on-board loads. This main circuit is equipped with a controllable switch controlled by the battery management system control unit. When the battery management system enters sleep mode, it only needs to keep the controllable switch on to maintain continuous voltage output and power the on-board loads.

[0004] However, when the battery management system is in sleep mode and supplies power to the vehicle load, it consumes a large current, causing the capacity of the lithium-ion battery pack to decrease rapidly. Users need to frequently recharge the lithium-ion battery pack, which affects the user experience. Summary of the Invention

[0005] The present application provides a battery management system for reducing current consumption when powering vehicle loads in sleep mode.

[0006] In a first aspect, the present application provides a battery management system, comprising: a current limiting circuit, a main circuit, and a battery management system control unit; the current limiting circuit is connected in parallel with the main circuit; wherein the current limiting circuit comprises a first controllable switch and a current limiting resistor; and the main circuit comprises a second controllable switch;

[0007] The first end of the first controllable switch is connected to the first end of the second controllable switch and the positive electrode of the battery pack, the second end of the first controllable switch is connected to the first end of the current-limiting resistor, the second end of the current-limiting resistor is connected to the second end of the second controllable switch and the input end of the load, and the output end of the load is connected to the negative electrode of the battery pack;

[0008] The control end of the first controllable switch and the control end of the second controllable switch are connected to the battery management system control unit, and are configured to be turned on or off under the control of the battery management system control unit;

[0009] When the battery management system is in a sleep mode, the battery management system control unit controls the first controllable switch to be turned on and controls the second controllable switch to be turned off, so that the battery pack supplies power to the load based on the current limiting circuit;

[0010] When the battery management system is in a normal operating mode, the battery management system control unit controls the first controllable switch and the second controllable switch to be turned on, so that the battery pack supplies power to the load based on the current limiting circuit and the main circuit.

[0011] Furthermore, in the battery management system as described above, the current limiting circuit further comprises: a sampling resistor;

[0012] The first end of the sampling resistor is connected to the second end of the first controllable switch, and the second end of the sampling resistor is connected to the first end of the current limiting resistor;

[0013] When the first controllable switch is turned on, the sampling resistor is used to sample the current passing through the current limiting circuit.

[0014] Furthermore, the battery management system as described above further includes: a first controllable switch driving unit;

[0015] The first controllable switch driving unit is connected to the control end of the first controllable switch and the battery management system control unit;

[0016] The first controllable switch driving unit is used to control the first controllable switch to be turned on or off under the control of the battery management system control unit.

[0017] Furthermore, the battery management system as described above further includes: a second controllable switch driving unit;

[0018] The second controllable switch driving unit is connected to the control end of the second controllable switch and the battery management system control unit;

[0019] The second controllable switch driving unit is used to control the on or off of the second controllable switch under the control of the battery management system control unit.

[0020] Furthermore, the battery management system as described above further includes: a current detection unit;

[0021] The current detection unit is connected to the sampling resistor and the battery management system control unit;

[0022] When the battery management system is in sleep mode, the current detection unit is used to detect the current collected by the sampling resistor and output a first current signal to the battery management system control unit based on the detection result. The first current signal is used to instruct the battery management system control unit to switch the battery management system from sleep mode to normal working mode.

[0023] Furthermore, the battery management system as described above further includes: a current trigger unit;

[0024] The current trigger unit is connected to the current detection unit, the second controllable switch driving unit and the battery management system control unit;

[0025] The current trigger unit is used to receive the first current signal output by the current detection unit, and under the control of the battery management system control unit, output a second current signal to the second controllable switch driving unit based on the received first current signal, wherein the second current signal is used to instruct the second controllable switch driving unit to control the second controllable switch to turn on.

[0026] Furthermore, the battery management system as described above further includes: a communication unit;

[0027] The communication unit is connected to the battery management system control unit and the charger, the input end of the charger is connected to the second end of the current limiting resistor and the second end of the second controllable switch, and the output end of the charger is connected to the negative electrode of the battery pack;

[0028] The communication unit is used to send a charging request to the charger under the control of the battery management system control unit, so that the charger charges the battery pack based on the current limiting circuit when the battery management system is in sleep mode based on the charging request, and charges the battery pack based on the current limiting circuit and the main circuit when the battery management system is in normal working mode.

[0029] Furthermore, in the battery management system as described above, the second controllable switch includes: a discharge switch and a charge switch;

[0030] When the battery management system is in a sleep mode, the battery management system control unit controls the first controllable switch to be turned on, and controls the discharge switch and the charge switch of the second controllable switch to be turned off, so that the battery pack supplies power to the load based on the current limiting circuit, or the charger charges the battery pack based on the current limiting circuit;

[0031] When the battery management system is in normal working mode, the battery management system control unit controls the first controllable switch to be turned on, and controls the discharge switch of the second controllable switch to be turned on and the charging switch to be turned off, or the charging switch to be turned on and the discharge switch to be turned off, so that the battery pack supplies power to the load based on the current limiting circuit and the main circuit, or the charger charges the battery pack based on the current limiting circuit and the main circuit.

[0032] Furthermore, the battery management system as described above further includes: a battery information acquisition unit;

[0033] The battery information acquisition unit is connected to the battery pack and the battery management system control unit;

[0034] The battery information acquisition unit is used to collect information about the battery pack when the battery management system is in normal operating mode, and send the collected information about the battery pack to the battery management system control unit; the battery management system control unit is used to determine whether the battery pack has a fault based on the received information about the battery pack, and if a fault occurs, control the first controllable switch and the second controllable switch to be disconnected.

[0035] Furthermore, in the battery management system as described above, the battery information acquisition unit includes: a current acquisition module;

[0036] One end of the current acquisition module is connected to the negative electrode of the battery pack, and the other end is connected to the load and the output end of the charger, and is used to collect current information of the battery pack.

[0037] The present application provides a battery management system, comprising a current limiting circuit having a first controllable switch and a current limiting resistor, a main circuit having a second controllable switch, and a battery management system control unit, wherein the current limiting circuit is connected in parallel with the main circuit and connected in series between the battery pack and the load, and the battery management system control unit is connected to the first controllable switch and the second controllable switch for controlling the on or off thereof. When the battery management system is in sleep mode, the first controllable switch is controlled to be on and the second controllable switch is controlled to be off, so that the battery pack supplies power to the load based on the current limiting circuit. When the battery management system is in normal working mode, the first controllable switch and the second controllable switch are controlled to be on, so that the battery pack supplies power to the load based on the current limiting circuit and the main circuit. In other words, the battery management system provided by the present application adds a current limiting circuit having a current limiting resistor connected in parallel with the main circuit, so that when the battery management system is in sleep mode, the load can be supplied with power based on the current limiting circuit, thereby effectively reducing the current consumption in sleep mode, thereby reducing the frequency of users recharging the battery pack, and improving the user experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0039] Figure 1 A schematic diagram of the structure of the battery management system provided in an embodiment of the present application;

[0040] Figure 2 A schematic diagram of the structure of the battery management system provided in an embodiment of the present application;

[0041] Figure 3 A schematic diagram of the structure of the battery management system provided in an embodiment of the present application;

[0042] Figure 4 A schematic diagram of the structure of the battery management system provided in an embodiment of the present application;

[0043] Figure 5 A schematic diagram of the structure of the battery management system provided in an embodiment of the present application;

[0044] Figure 6 A schematic diagram of the structure of the battery management system provided in an embodiment of the present application;

[0045] Figure 7 A schematic diagram of the structure of the battery management system provided in an embodiment of the present application;

[0046] Figure 8 A schematic diagram of the structure of the battery management system provided in an embodiment of the present application;

[0047] Figure 9 A schematic diagram of the structure of the battery management system provided in an embodiment of the present application;

[0048] Figure 10 A schematic diagram of the structure of the battery management system provided in an embodiment of the present application;

[0049] Figure 11 A schematic diagram of the structure of the battery management system provided in an embodiment of the present application.

[0050] The above drawings illustrate specific embodiments of the present application, which will be described in more detail below. These drawings and the textual description are not intended to limit the scope of the present application in any way, but rather to illustrate the concepts of the present application to those skilled in the art by reference to specific embodiments. DETAILED DESCRIPTION

[0051] Exemplary embodiments are described in detail herein, with examples illustrated in the accompanying drawings. When the following description refers to the drawings, identical numerals in different drawings represent identical or similar elements, unless otherwise indicated. The embodiments described in the following exemplary embodiments are not intended to represent all embodiments consistent with the present application. Rather, they are merely examples of battery management systems consistent with certain aspects of the present application.

[0052] The lithium-ion battery pack of a new energy vehicle consists of a battery pack and a battery management system. The battery management system manages the battery pack to power the onboard loads. However, when the battery management system is inactive for a period of time, it enters sleep mode. However, the onboard loads still require continuous power. Therefore, to ensure that the battery pack can maintain a continuous voltage output to power the onboard loads when the battery management system enters sleep mode, a main circuit for powering the onboard loads can be added between the battery pack and the onboard loads. This main circuit is equipped with a controllable switch. When the battery management system is not in sleep mode, that is, in normal operation mode, the battery management system can collect information from the battery pack and control the controllable switch to turn on or off to manage the battery pack. When the battery management system enters sleep mode, the battery management system control unit turns on the controllable switch, thereby maintaining a continuous voltage output to power the onboard loads.

[0053] However, when the battery management system is in sleep mode and supplies power to the vehicle load, it consumes a large current, causing the capacity of the lithium-ion battery pack to decrease rapidly. Users need to frequently recharge the lithium-ion battery pack, which affects the user experience.

[0054] The battery management system provided in this application is intended to solve the above technical problems in the prior art.

[0055] The following specific embodiments describe in detail the technical solution of the present application and how the technical solution of the present application solves the above-mentioned technical problems. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. The embodiments of the present application will be described below in conjunction with the accompanying drawings.

[0056] Example 1

[0057] Figure 1 A schematic diagram of the battery management system provided in the embodiment of the present application is shown in FIG. Figure 1 As shown, the battery management system provided in this embodiment includes: a current limiting circuit 1, a main circuit 2, and a battery management system control unit 3. The current limiting circuit 1 is connected in parallel with the main circuit 2. The current limiting circuit 1 includes a first controllable switch 11 and a current limiting resistor 12. The main circuit 2 includes a second controllable switch 21.

[0058] In this embodiment, the first end of the first controllable switch 11 is connected to the first end of the second controllable switch 21 and the positive electrode of the battery pack. The second end of the first controllable switch 11 is connected to the first end of the current-limiting resistor 12. The second end of the current-limiting resistor 12 is connected to the second end of the second controllable switch 21 and the input end of the load. The output end of the load is connected to the negative electrode of the battery pack. The control end of the first controllable switch 11 and the control end of the second controllable switch 21 are connected to the battery management system control unit 3 to be turned on or off under the control of the battery management system control unit 3.

[0059] The first controllable switch 11 and the second controllable switch 21 may be metal-oxide-semiconductor field-effect transistors (MOSFETs) or other suitable switching elements, which are not limited in this embodiment.

[0060] In addition, the battery pack may be a battery pack having a voltage consistent with the load voltage, such as a 12V battery pack consisting of four lithium batteries connected in series, or other suitable battery packs, which are not limited in this embodiment.

[0061] In actual applications, when the battery management system is in sleep mode, the battery management system control unit 3 controls the first controllable switch 11 to be turned on and the second controllable switch 21 to be turned off, so that the battery pack supplies power to the load based on the current limiting circuit 1. Specifically, current flows from the positive electrode (BAT+) of the battery pack, flows into the load through the current limiting circuit 1, and then flows back to the negative electrode (BAT-) of the battery pack.

[0062] When the battery management system is in normal operating mode, the battery management system control unit 3 controls the first controllable switch 11 and the second controllable switch 21 to conduct, so that the battery pack supplies power to the load based on the current limiting circuit 1 and the main circuit 2. Specifically, current flows from the positive electrode (BAT+) of the battery pack, passes through the current limiting circuit 1 and the main circuit 2, flows into the load, and then flows back to the negative electrode (BAT-) of the battery pack.

[0063] Figure 2 A schematic diagram of the battery management system provided in the embodiment of the present application is shown in FIG. Figure 2 As shown, based on the above embodiment 1, the battery management system provided by this embodiment, the current limiting circuit 1 further includes: a sampling resistor 13.

[0064] In this embodiment, a first end of the sampling resistor 13 is connected to a second end of the first controllable switch 11 , and a second end of the sampling resistor 13 is connected to a first end of the current limiting resistor 12 .

[0065] In practical applications, when the first controllable switch 11 is turned on, the sampling resistor 13 can sample the current passing through the current limiting circuit 1 for subsequent processing.

[0066] In an optional embodiment, Figure 3 A schematic diagram of the battery management system provided in the embodiment of the present application is shown in FIG. Figure 3 As shown, based on the above embodiment 1, the battery management system provided in this embodiment further includes: a first controllable switch driving unit 4.

[0067] In this embodiment, the first controllable switch driving unit 4 is connected to the control end of the first controllable switch 11 and the battery management system control unit 3 .

[0068] In actual applications, the first controllable switch driving unit 4 can control the conduction or disconnection of the first controllable switch 11 under the control of the battery management system control unit 3. Since the current of the current limiting circuit 1 is very small and the power consumption is very low, the first controllable switch 11 can be kept on regardless of whether the battery management system is in sleep mode or normal working mode, when there is no fault in the battery pack. In one example, the first controllable switch driving unit 4 can be a low-power drive holding circuit. The battery management system control unit 3 only needs to send a high-level control signal to the drive holding circuit, and the drive holding circuit can control the first controllable switch 11 to remain in the on state, thereby eliminating the need for the battery management system control unit 3 to continuously output current, effectively reducing power consumption. When a fault occurs in the battery pack, the battery management system control unit 3 sends a low-level control signal to the drive holding circuit, and the drive holding circuit can control the first controllable switch 11 to be disconnected, thereby achieving circuit protection.

[0069] In an optional embodiment, Figure 4 A schematic diagram of the battery management system provided in the embodiment of the present application is shown in FIG. Figure 4 As shown, based on the above embodiment 1, the battery management system provided in this embodiment further includes: a second controllable switch driving unit 5.

[0070] The second controllable switch driving unit 5 is connected to the control end of the second controllable switch 21 and the battery management system control unit 3 .

[0071] In practical applications, the second controllable switch driving unit 5 is used to control the conduction or disconnection of the second controllable switch 21 under the control of the battery management system control unit 3. In one example, the second controllable switch driving unit 5 can be a low-power drive circuit. When the battery management system is in normal operating mode, the battery management system control unit 3 only needs to send a high-level control signal to the drive circuit, and the drive circuit can control the second controllable switch 21 to conduct. The battery pack can power the load based on the main circuit 2, thereby eliminating the need for the battery management system control unit 3 to continuously output current, effectively reducing power consumption. When a battery pack fault occurs, the battery management system control unit 3 sends a low-level control signal to the drive circuit, and the drive circuit can control the second controllable switch 21 to disconnect, thereby achieving circuit protection.

[0072] The battery management system provided in this embodiment includes a current limiting circuit having a first controllable switch and a current limiting resistor, a main circuit having a second controllable switch, and a battery management system control unit. The current limiting circuit is connected in parallel with the main circuit and connected in series between the battery pack and the load. The battery management system control unit is connected to the first controllable switch and the second controllable switch for controlling their conduction or disconnection. When the battery management system is in sleep mode, the first controllable switch is controlled to be turned on and the second controllable switch is controlled to be turned off, so that the battery pack supplies power to the load based on the current limiting circuit. When the battery management system is in normal operating mode, the first controllable switch and the second controllable switch are controlled to be turned on, so that the battery pack supplies power to the load based on the current limiting circuit and the main circuit. That is, in this embodiment of the application, a current limiting circuit having a current limiting resistor is added in parallel with the main circuit, so that when the battery management system is in sleep mode, the current limiting circuit can be used to supply power to the load based on the current limiting circuit, thereby effectively reducing current consumption in sleep mode, thereby reducing the frequency of users recharging the battery pack and improving the user experience.

[0073] Example 2

[0074] Figure 5 A schematic diagram of the battery management system provided in the embodiment of the present application is shown in FIG. Figure 5 As shown, based on the above embodiment 1, the battery management system provided in this embodiment further includes: a current detection unit 6.

[0075] In this embodiment, the current detection unit 6 is connected to the sampling resistor 13 and the battery management system control unit 3 .

[0076] In actual applications, when the battery management system is in sleep mode, the current detection unit 6 can detect the current collected by the sampling resistor 13, and output a first current signal to the battery management system control unit 3 based on the detection result. The first current signal is used to instruct the battery management system control unit 3 to switch the battery management system from sleep mode to normal working mode.

[0077] In one example, the current detection unit 6 can be a low-power current detection circuit. When the battery management system is in sleep mode, if the current detection circuit detects that the current collected by the sampling resistor 13 is greater than a preset current threshold, it can output a first current signal CUR_DET to the battery management system control unit 3. When the battery management system control unit 3 receives the first current signal CUR_DET, it can switch the battery management system from sleep mode to normal working mode, thereby controlling the second controllable switch 21 to be turned on. The battery pack can jointly power the load based on the current limiting circuit 1 and the main circuit 2, avoiding the load being powered by the current limiting circuit 1, and insufficient power supply causing the load to fail to work. In addition, it can also avoid the current limiting circuit 1 being continuously overloaded, causing the current limiting resistor 12 to overheat and be damaged.

[0078] Figure 6 A schematic diagram of the battery management system provided in the embodiment of the present application is shown in FIG. Figure 6 As shown, based on the above-mentioned embodiment 2, the battery management system provided in this embodiment further includes: a current trigger unit 7.

[0079] In this embodiment, the current trigger unit 7 is connected to the current detection unit 6 , the second controllable switch driving unit 5 and the battery management system control unit 3 .

[0080] In actual application, the current trigger unit 7 is used to receive the first current signal output by the current detection unit 6, and under the control of the battery management system control unit 3, based on the received first current signal, output a second current signal to the second controllable switch driving unit 5, and the second current signal is used to instruct the second controllable switch driving unit 5 to control the second controllable switch 21 to turn on.

[0081] Continuing with the above example, while the current detection unit 6 outputs the first current signal CUR_DET to the battery management system control unit 3, it also outputs the first current signal CUR_DET to the current trigger unit 7. After receiving the signal, the current trigger unit 7 can output the second current signal CUR_TR to the second controllable switch driving unit 5 under the control of the battery management system control unit 3. After the second controllable switch driving unit 5 receives the second current signal CUR_TR, it can control the second controllable switch 21 to turn on. The battery pack can jointly power the load based on the current limiting circuit 1 and the main circuit 2, so there is no need to wait for the battery management system to switch from sleep mode to normal working mode before the battery management system control unit 3 controls the second controllable switch 21 to turn on, which effectively improves the response speed of the system.

[0082] In the battery management system provided in this embodiment, the current detection unit can detect the current collected by the sampling resistor and output a first current signal, so that the battery management system control unit can switch the battery management system from the sleep mode to the normal working mode according to the first current signal. At the same time, the current trigger unit can output the second current signal based on the first current signal, so as to quickly control the conduction of the second controllable switch, so that the battery pack can supply power to the load based on the current limiting circuit and the main circuit, effectively avoiding the load being unable to work due to insufficient power supply caused by the current limiting circuit, and avoiding the current limiting resistor being overheated and damaged due to continuous overload of the current limiting circuit.

[0083] Example 3

[0084] Figure 7 A schematic diagram of the battery management system provided in the embodiment of the present application is shown in FIG. Figure 7 As shown, based on the above embodiment 1, the battery management system provided in this embodiment further includes: a communication unit 8.

[0085] In this embodiment, the communication unit 8 is connected to the battery management system control unit 3 and the charger, the input end of the charger is connected to the second end of the current limiting resistor 11 and the second end of the second controllable switch 21, and the output end of the charger is connected to the negative pole of the battery pack.

[0086] In actual applications, the communication unit 8 can send a charging request to the charger under the control of the battery management system control unit 3, so that the charger charges the battery pack based on the current limiting circuit 1 when the battery management system is in sleep mode based on the charging request, and charges the battery pack based on the current limiting circuit 1 and the main circuit 2 when the battery management system is in normal working mode.

[0087] In one example, when the communication unit 8, under the control of the battery management system control unit 3, sends a charge request to the charger, if the battery management system is in sleep mode (i.e., the first controllable switch 11 is on and the second controllable switch 21 is off), the charger can charge the battery pack based on the current limiting circuit 1. During charging, current flows from the positive electrode of the charger, passes through the current limiting circuit 1, flows into the positive electrode (BAT+) of the battery pack, and then flows back from the negative electrode (BAT-) of the battery pack to the negative electrode of the charger. If the battery management system is in normal operating mode (i.e., the first controllable switch 11 is on and the second controllable switch 21 is also on), the charger can charge the battery pack based on the current limiting circuit 1 and the main circuit 2. During charging, current flows from the positive electrode of the charger, passes through the current limiting circuit 1 and the main circuit 2, flows into the positive electrode (BAT+) of the battery pack, and then flows back from the negative electrode (BAT-) of the battery pack to the negative electrode of the charger.

[0088] Figure 8 A schematic diagram of the battery management system provided in the embodiment of the present application is shown in FIG. Figure 8 As shown, based on the above-mentioned embodiment 3, the battery management system provided in this embodiment, the second controllable switch 21 includes: a discharge switch 211 and a charge switch 212 .

[0089] In this embodiment, when the battery management system is in sleep mode, the battery management system control unit 3 can control the first controllable switch 11 to be turned on, and control the discharge switch 211 and the charging switch 212 of the second controllable switch 21 to be turned off, so that the battery pack supplies power to the load based on the current limiting circuit 1, or the charger charges the battery pack based on the current limiting circuit 1.

[0090] When the battery management system is in normal working mode, the battery management system control unit 3 can control the first controllable switch 11 to be turned on, and control the discharge switch 211 of the second controllable switch 21 to be turned on and the charging switch 212 to be turned off, or the charging switch 212 to be turned on and the discharge switch 211 to be turned off, so that the battery pack supplies power to the load based on the current limiting circuit 1 and the main circuit 2, or the charger charges the battery pack based on the current limiting circuit 1 and the main circuit 2.

[0091] In actual application, if the battery management system is in sleep mode, when the charger does not receive the charging request sent by the communication unit 8, the battery management system control unit 3 can control the first controllable switch 11 to be turned on, and control the discharge switch 211 and the charging switch 212 of the second controllable switch 21 to be disconnected, so that the battery pack can supply power to the load based on the current limiting circuit 1. When the charger receives the charging request sent by the communication unit 8, the battery management system control unit 3 can control the first controllable switch 11 to be turned on, and control the discharge switch 211 and the charging switch 212 of the second controllable switch 21 to be disconnected, so that the charger can charge the battery pack based on the current limiting circuit 1.

[0092] If the battery management system is in normal working mode, when the charger does not receive the charging request sent by the communication unit 8, the battery management system control unit 3 can control the first controllable switch 11 to be turned on, and control the discharge switch 211 of the second controllable switch 21 to be turned on, and the charging switch 212 to be turned off, so that the battery pack can supply power to the load based on the current limiting circuit 1 and the main circuit 2. When the charger receives the charging request sent by the communication unit 8, the battery management system control unit 3 can control the first controllable switch 11 to be turned on, and control the charging switch 212 of the second controllable switch 21 to be turned on, and the discharge switch 211 to be turned off, so that the charger can charge the battery pack based on the current limiting circuit 1 and the main circuit 2.

[0093] The battery management system provided in this embodiment controls charging and discharging through a charging switch and a discharging switch, thereby ensuring smooth switching of charging and discharging of the battery pack.

[0094] Example 4

[0095] Figure 9 A schematic diagram of the battery management system provided in the embodiment of the present application is shown in FIG. Figure 9 As shown, based on the above embodiment 1, the battery management system provided in this embodiment further includes: a battery information collection unit 9.

[0096] In this embodiment, the battery information acquisition unit 9 is connected to the battery pack and the battery management system control unit 3 .

[0097] In actual applications, the battery information collection unit 9 can collect battery pack information when the battery management system is in normal operating mode, and send the collected battery pack information to the battery management system control unit 3. The battery management system control unit 3 is configured to determine whether the battery pack has a fault based on the received battery pack information. If a fault occurs, the battery management system control unit 3 controls the first controllable switch 11 and the second controllable switch 21 to be disconnected, thereby achieving circuit protection.

[0098] Figure 10 A schematic diagram of the battery management system provided in the embodiment of the present application is shown in FIG. Figure 10 As shown, based on the above fourth embodiment, the battery management system provided by this embodiment includes a battery information acquisition unit 9 including a current acquisition module 91 .

[0099] In this embodiment, one end of the current acquisition module 91 is connected to the negative pole of the battery pack, and the other end is connected to the load and the output end of the charger. It can collect the current information of the battery pack so that the battery management system control unit 3 can judge whether the battery pack has a fault based on the current information of the battery pack collected by the current acquisition module 91. If a fault occurs, the first controllable switch 11 and the second controllable switch 21 are controlled to be disconnected, thereby achieving circuit protection.

[0100] The battery management system provided in this embodiment collects battery pack status information through the battery information collection unit and sends it to the battery management system control unit, so that the first controllable switch and the second controllable switch can be promptly controlled to disconnect when a battery pack failure occurs, thereby achieving circuit protection.

[0101] Example 5

[0102] Figure 11 A schematic diagram of the battery management system provided in the embodiment of the present application is shown in FIG. Figure 11 As shown, when the above-mentioned embodiments 1 to 4 are implemented in combination, the battery management system provided in this embodiment includes: a current limiting circuit 1, a main circuit 2 connected in parallel with the current limiting circuit 1, a battery management system control unit 3, a first controllable switch driving unit 4, a second controllable switch driving unit 5, a current detection unit 6, a current triggering unit 7, a communication unit 8, and a battery information acquisition unit 9. The current limiting circuit 1 includes a first controllable switch 11, a current limiting resistor 12, and a sampling resistor 13; the main circuit 2 includes a second controllable switch 21, which includes a discharge switch 211 and a charge switch 212; and the battery information acquisition unit 9 includes a current acquisition module 91.

[0103] In this embodiment, the first end of the first controllable switch 11 is connected to the first end of the second controllable switch 21, and are jointly connected to the positive electrode of the battery pack. The second end of the first controllable switch 11 is connected to the first end of the sampling resistor 13, the second end of the sampling resistor 13 is connected to the first end of the current limiting resistor 12, the second end of the current limiting resistor 12 is connected to the second end of the second controllable switch 21, and are jointly connected to the input end of the load and the charger through the positive terminal. The output end of the load and the charger is connected to one end of the current acquisition module 91 of the battery information acquisition unit 9 through the negative terminal, and the other end of the current acquisition module 91 is connected to the negative electrode of the battery pack.

[0104] The first controllable switch driving unit 4 is connected to the control end of the first controllable switch 11 and the battery management system control unit 3, the second controllable switch driving unit 5 is connected to the control end of the second controllable switch 21 and the battery management system control unit 3, the current detection unit 6 is connected to the sampling resistor 13 and the battery management system control unit 3, the current trigger unit 7 is connected to the current detection unit 6, the second controllable switch driving unit 5 and the battery management system control unit 3, the communication unit 8 is connected to the battery management system control unit 3 and the charger, and the battery information acquisition unit 9 is connected to the battery pack and the battery management system control unit 3.

[0105] The first controllable switch 11 is a knife switch, and the second controllable switch 21 is a metal-oxide-semiconductor field-effect transistor (MOSFET). The first controllable switch driving unit 4 is a low-power drive holding circuit, the second controllable switch driving unit 5 is a low-power drive circuit, the current detection unit 6 is a low-power current detection circuit, and the current trigger unit 7 is a low-power current trigger circuit.

[0106] In addition, the load is a 12V on-board load, the charger is a 12V on-board charger, and the battery pack is a 12V battery pack composed of 4 lithium batteries connected in series.

[0107] In actual application, if the battery management system is in sleep mode, when the charger does not receive the charging request sent by the communication unit 8, the battery management system control unit 3 can control the first controllable switch 11 to be turned on, and control the discharge switch 211 and the charging switch 212 of the second controllable switch 21 to be disconnected, so that the battery pack can supply power to the load based on the current limiting circuit 1. When the charger receives the charging request sent by the communication unit 8, the battery management system control unit 3 can control the first controllable switch 11 to be turned on, and control the discharge switch 211 and the charging switch 212 of the second controllable switch 21 to be disconnected, so that the charger can charge the battery pack based on the current limiting circuit 1.

[0108] When powering the load, current flows out from the positive electrode (BAT+) of the battery pack, flows into the load through the current limiting circuit 1 and the 12V+ terminal, and then flows back to the negative electrode (BAT-) of the battery pack through the 12V- terminal and the current acquisition module 91.

[0109] During charging, current flows out from the positive electrode of the charger, flows into the positive electrode (BAT+) of the battery pack through the current limiting circuit 1 and the 12V+ terminal, and then flows from the negative electrode (BAT-) of the battery pack through the 12V- terminal and the current acquisition module 91 back to the negative electrode of the charger.

[0110] If the battery management system is in normal working mode, when the charger does not receive the charging request sent by the communication unit 8, the battery management system control unit 3 can control the first controllable switch 11 to be turned on, and control the discharge switch 211 of the second controllable switch 21 to be turned on, and the charging switch 212 to be turned off, so that the battery pack can supply power to the load based on the current limiting circuit 1 and the main circuit 2. When the charger receives the charging request sent by the communication unit 8, the battery management system control unit 3 can control the first controllable switch 11 to be turned on, and control the charging switch 212 of the second controllable switch 21 to be turned on, and the discharge switch 211 to be turned off, so that the charger can charge the battery pack based on the current limiting circuit 1 and the main circuit 2.

[0111] When powering the load, current flows out from the positive electrode (BAT+) of the battery pack, passes through the current limiting circuit 1 and the main circuit 2, flows into the load through the 12V+ terminal, and then flows back to the negative electrode (BAT-) of the battery pack through the 12V- terminal and the current acquisition module 91.

[0112] During charging, the current flows out from the positive pole of the charger, passes through the current limiting circuit 1 and the main circuit 2, and flows into the positive pole (BAT+) of the battery pack through the 12V+ terminal, and then flows from the negative pole (BAT-) of the battery pack through the 12V- terminal and the current acquisition module 91 back to the negative pole of the charger.

[0113] In addition, when the battery management system is in sleep mode, that is, when the first controllable switch 11 is turned on, the sampling resistor 13 can sample the current passing through the current limiting circuit 1, and the current detection unit 6 can detect the current collected by the sampling resistor 13. If the current detection circuit detects that the current collected by the sampling resistor 13 is greater than the preset current threshold, it can output a first current signal CUR_DET to the battery management system control unit 3 and the current trigger unit 7. When the battery management system control unit 3 receives the first current signal CUR_DET, it can switch the battery management system from sleep mode to normal operation. mode, after the current trigger unit 7 receives the first current signal CUR_DET, it can output the second current signal CUR_TR to the second controllable switch driving unit 5 under the control of the battery management system control unit 3. After the second controllable switch driving unit 5 receives the second current signal CUR_TR, it can control the second controllable switch 21 to be turned on. The battery pack can jointly power the load based on the current limiting circuit 1 and the main circuit 2, avoiding the load being unable to work due to insufficient power supply caused by the current limiting circuit 1. In addition, it can also avoid the current limiting circuit 1 being continuously overloaded and causing the current limiting resistor 12 to overheat and be damaged.

[0114] When the battery management system is in normal operating mode, the battery information acquisition unit 9 can collect battery pack information. In addition to the current acquisition module 91, the battery information acquisition unit 9 also includes a total voltage acquisition module, a cell voltage acquisition module, a cell temperature acquisition module, and a cell balancing module. This unit can collect information such as the cell voltage, temperature, and current of the battery pack and send the collected battery pack information to the battery management system control unit 3. The battery management system control unit 3 can determine whether the battery pack has a fault based on the received battery pack information. If a fault occurs, the battery management system control unit 3 controls the first controllable switch 11 and the second controllable switch 21 to open, thereby achieving circuit protection.

[0115] The battery management system provided in this embodiment adds a current limiting circuit with a current limiting resistor connected in parallel with the main circuit, so that when the battery management system is in sleep mode, the load can be powered based on the current limiting circuit, thereby effectively reducing the current consumption in sleep mode, thereby reducing the frequency of users recharging the battery pack and improving the user experience.

[0116] In the several embodiments provided in this application, it should be understood that the disclosed battery management system can be implemented in other ways. For example, the battery management system embodiments described above are merely illustrative. For example, the division of modules is only a logical function division. In actual implementation, there may be other division methods, such as multiple modules or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, and the indirect coupling or communication connection of the battery management system or modules can be electrical, mechanical or other forms.

[0117] Modules described as separate components may or may not be physically separate, and components shown as modules may or may not be physical modules, that is, they may be located in one place or distributed across multiple network modules. Some or all of these modules may be selected to achieve the purpose of this embodiment based on actual needs.

[0118] In addition, the functional modules in the various embodiments of the present application may be integrated into a single processing module, or each module may exist physically separately, or two or more modules may be integrated into a single module. The aforementioned integrated modules may be implemented in the form of hardware or in the form of hardware plus software functional modules.

[0119] In addition, although adopting specific order to describe each operation, this should be understood as requiring such operation to be carried out with shown specific order or with sequential order, or requiring all illustrated operations to be carried out to obtain desired result.Under certain environment, multitasking and parallel processing may be advantageous.Similarly, although comprising some specific implementation details in the above discussion, these should not be interpreted as limiting the scope of the application.Some features described in the context of independent embodiment can also be implemented in a single implementation in combination.On the contrary, the various features described in the context of independent implementation also can be implemented in a plurality of implementations individually or in the mode of any suitable subcombination.

[0120] Those skilled in the art will readily appreciate other embodiments of the present application after considering the specification and practicing the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of the present application that follow the general principles of the present application and include common knowledge or customary techniques in the art not disclosed herein. The description and examples are to be considered as exemplary only, and the true scope and spirit of the present application are indicated by the following claims.

[0121] It should be understood that the present application is not limited to the exact structure described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present application is limited only by the appended claims.

Claims

1. A battery management system, characterized in that: include: A current limiting circuit, a main circuit, and a battery management system control unit; the current limiting circuit is connected in parallel with the main circuit; wherein the current limiting circuit includes a first controllable switch, a sampling resistor, and a current limiting resistor; and the main circuit includes a second controllable switch; The first end of the first controllable switch is connected to the first end of the second controllable switch and the positive electrode of the battery pack, the first end of the sampling resistor is connected to the second end of the first controllable switch, the second end of the current limiting resistor is connected to the second end of the second controllable switch and the input end of the load, the output end of the load is connected to the negative electrode of the battery pack, and the second end of the sampling resistor is connected to the first end of the current limiting resistor; The control end of the first controllable switch and the control end of the second controllable switch are connected to the battery management system control unit, and are configured to be turned on or off under the control of the battery management system control unit; When the battery management system is in a sleep mode, the battery management system control unit controls the first controllable switch to be turned on and controls the second controllable switch to be turned off, so that the battery pack supplies power to the load based on the current limiting circuit, and simultaneously samples the current passing through the current limiting circuit; When the current detected by the sampling resistor exceeds a preset threshold, the battery management system control unit is triggered to switch to a normal operating mode, and the second controllable switch is controlled to be turned on, so that the battery pack supplies power to the load through the current limiting circuit and the main circuit; When the battery management system is in a normal working mode, the battery management system control unit controls the first controllable switch and the second controllable switch to be turned on, so that the battery pack supplies power to the load based on the current limiting circuit and the main circuit; The battery management system further includes: a battery information acquisition unit; the battery information acquisition unit is connected to the battery pack and the battery management system control unit.

2. The battery management system according to claim 1, characterized in that: The battery management system further includes: a first controllable switch driving unit; The first controllable switch driving unit is connected to the control end of the first controllable switch and the battery management system control unit; The first controllable switch driving unit is used to control the first controllable switch to be turned on or off under the control of the battery management system control unit.

3. The battery management system according to claim 1, characterized in that: The battery management system further includes: a second controllable switch driving unit; The second controllable switch driving unit is connected to the control end of the second controllable switch and the battery management system control unit; The second controllable switch driving unit is used to control the on or off of the second controllable switch under the control of the battery management system control unit.

4. The battery management system according to claim 3, characterized in that: The battery management system further includes: a current detection unit; The current detection unit is connected to the sampling resistor and the battery management system control unit; When the battery management system is in sleep mode, the current detection unit is used to detect the current collected by the sampling resistor and output a first current signal to the battery management system control unit based on the detection result. The first current signal is used to instruct the battery management system control unit to switch the battery management system from sleep mode to normal working mode.

5. The battery management system according to claim 4, characterized in that: The battery management system further includes: a current trigger unit; The current trigger unit is connected to the current detection unit, the second controllable switch driving unit and the battery management system control unit; The current trigger unit is used to receive the first current signal output by the current detection unit, and under the control of the battery management system control unit, output a second current signal to the second controllable switch driving unit based on the received first current signal, wherein the second current signal is used to instruct the second controllable switch driving unit to control the second controllable switch to turn on.

6. The battery management system according to claim 1, characterized in that: The battery management system further includes: a communication unit; The communication unit is connected to the battery management system control unit and the charger, the input end of the charger is connected to the second end of the current limiting resistor and the second end of the second controllable switch, and the output end of the charger is connected to the negative electrode of the battery pack; The communication unit is used to send a charging request to the charger under the control of the battery management system control unit, so that the charger charges the battery pack based on the current limiting circuit when the battery management system is in sleep mode based on the charging request, and charges the battery pack based on the current limiting circuit and the main circuit when the battery management system is in normal working mode.

7. The battery management system according to claim 6, characterized in that: The second controllable switch includes: a discharge switch and a charge switch; When the battery management system is in a sleep mode, the battery management system control unit controls the first controllable switch to be turned on, and controls the discharge switch and the charge switch of the second controllable switch to be turned off, so that the battery pack supplies power to the load based on the current limiting circuit, or the charger charges the battery pack based on the current limiting circuit; When the battery management system is in normal working mode, the battery management system control unit controls the first controllable switch to be turned on, and controls the discharge switch of the second controllable switch to be turned on and the charging switch to be turned off, or the charging switch to be turned on and the discharge switch to be turned off, so that the battery pack supplies power to the load based on the current limiting circuit and the main circuit, or the charger charges the battery pack based on the current limiting circuit and the main circuit.

8. The battery management system according to claim 1, characterized in that: The battery information acquisition unit is used to collect information about the battery pack when the battery management system is in normal operating mode, and send the collected information about the battery pack to the battery management system control unit; the battery management system control unit is used to determine whether the battery pack has a fault based on the received information about the battery pack, and if a fault occurs, control the first controllable switch and the second controllable switch to be disconnected.

9. The battery management system according to claim 8, characterized in that: The battery information acquisition unit includes: a current acquisition module; One end of the current acquisition module is connected to the negative electrode of the battery pack, and the other end is connected to the load and the output end of the charger, and is used to collect current information of the battery pack.

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