Battery management system and power transmission device

Abstract

The utility model discloses a battery management system and a power transmission device, and the system comprises a charging and discharging circuit which comprises a first external terminal, a protection unit, a power connection unit, a voltage dividing unit and a second external terminal which are connected in series, and the power connection unit is used for connecting a battery pack; a first end of the first acquisition unit is connected with the power connection unit, a second end of the first acquisition unit is connected with the voltage division unit, a third end of the first acquisition unit is connected with the protection unit, and the first acquisition unit is used for acquiring first main loop current flowing through the voltage division unit; when the first main loop current is greater than a preset current threshold value, the protection unit is controlled to disconnect the charging and discharging circuit; the first end of the second acquisition unit is connected with the fourth end of the first acquisition unit, the second end of the second acquisition unit is connected with the voltage division unit, the third end of the second acquisition unit is connected with the protection unit, and the second acquisition unit is used for acquiring second main loop current flowing through the voltage division unit. When the second main loop current is greater than the current threshold value, the protection unit is controlled to disconnect the charging and discharging circuit; and the second acquisition unit further acquires the first main loop current, performs difference value operation on the first main loop current and the second main loop current, and controls the protection unit to disconnect the charging and discharging circuit when the acquired difference value is greater than a preset difference value threshold value. In this way, the reliability of the battery protection circuit can be improved.

Description

Technical Field

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

[0002] In the prior art, battery management sampling is mainly performed through a single-loop current collection method. When the collection chip fails, the battery pack failure cannot be transmitted to the system in time, which will cause the protection device installed in the circuit to fail and the reliability of the protection device is insufficient. Utility Model Content

[0003] The present application mainly provides a battery management system and a power transmission device to solve the problem that the existing acquisition method cannot protect the circuit when the acquisition chip fails.

[0004] In order to solve the above technical problems, a technical solution adopted in the present application is: to provide a battery management system, the battery management system comprising: a charging and discharging circuit, comprising a first external terminal, a protection unit, a power connection unit, a voltage divider unit and a second external terminal connected in series, the power connection unit is used to connect a battery pack; a first acquisition unit, the first end of the first acquisition unit is connected to the power connection unit, the second end of the first acquisition unit is connected to the voltage divider unit, the third end of the first acquisition unit is connected to the protection unit, the first acquisition unit is used to collect a first main loop current flowing through the voltage divider unit, and control the protection unit to disconnect the charging and discharging when the first main loop current is greater than a preset current threshold. circuit; a second acquisition unit, a first end of the second acquisition unit is connected to the fourth end of the first acquisition unit, a second end of the second acquisition unit is connected to the voltage divider unit, a third end of the second acquisition unit is connected to the protection unit, the second acquisition unit is used to acquire the second main loop current flowing through the voltage divider unit, and control the protection unit to disconnect the charge and discharge circuit when the second main loop current is greater than the current threshold; wherein the second acquisition unit further acquires the first main loop current and performs a difference operation between the first main loop current and the second main loop current, and controls the protection unit to disconnect the charge and discharge circuit when the acquired acquisition difference is greater than a preset difference threshold.

[0005] The voltage on the voltage divider unit is collected by the first and second collection units to calculate the main loop current of the charging and discharging circuit, and the collected main loop current value is compared with the preset current threshold to determine whether the current main loop is abnormal, thereby completing the first level of protection for the battery; the main loop current collected by the first and second collection units is subtracted and compared with the preset difference threshold to determine for the second time whether the collection unit and the main loop are normal, thereby avoiding the failure of the main loop to be discovered in time due to a failure of the collection unit, thereby completing the second level of protection for the battery and improving the reliability of the battery protection circuit.

[0006] In some embodiments, the first acquisition unit includes a simulation unit.

[0007] By setting up an analog unit in the first acquisition unit, the voltage, current and other parameters of the battery pack installed on the power connection unit can be measured, and the charging and discharging process of the battery pack can be controlled, which is beneficial to improving the management efficiency of the battery.

[0008] In some embodiments, the second acquisition unit includes a microprocessor.

[0009] By arranging a microprocessor in the second acquisition unit, the microprocessor works in coordination with the first acquisition unit to complete the monitoring, control and protection functions of the battery pack.

[0010] In some embodiments, the voltage dividing unit includes at least one resistor; when the voltage dividing unit includes a plurality of resistors, the plurality of resistors are connected in series.

[0011] By connecting a resistor in series to the main circuit, the voltage of the main circuit can be shared. Increasing the voltage difference across the voltage divider unit can provide a suitable main circuit current value for other electrical appliances without changing the power supply.

[0012] In some embodiments, the resistor type includes at least one of a fixed resistor, an adjustable resistor, a variable resistor, a current transformer, and a resistance-variable resistor.

[0013] By flexibly matching and using various types of resistors, the voltage divider unit can provide a variety of different sampling resistance values ​​while dividing the voltage for the charging and discharging circuit, so that the first and second acquisition units can sample multiple times at different resistance values, thereby improving the numerical accuracy of the first and second main circuit currents.

[0014] In some embodiments, the protection unit includes a MOS tube and a driver chip; the source and drain of the MOS tube are connected in series to the main loop of the charge and discharge circuit, and are used to connect or disconnect the charge and discharge circuit; the driver chip is connected to the gate of the MOS tube and is connected to the first acquisition unit and the second acquisition unit, and is used to receive control signals of the first acquisition unit and the second acquisition unit and control the switch of the MOS tube.

[0015] By controlling the MOS tube switch through the driver chip, the main circuit can be disconnected in time when a circuit fails, avoiding abnormal power supply from damaging other power supplies or electrical appliances in the circuit, thereby protecting the charging and discharging circuits and battery packs.

[0016] In some embodiments, the driver chip includes: a first control input terminal, used to receive the control signal sent by the first acquisition unit; a second control input terminal, used to receive the control signal sent by the second acquisition unit; a signal processing circuit, connected to the first control input terminal and the second control terminal, used to process and decode the signal obtained by the control input terminal to generate a level control signal for driving the gate of the MOS tube; a control output terminal, connected to the signal processing circuit, used to output the level signal generated by the signal processing circuit to control the MOS tube to be turned on or off.

[0017] The driver chip controls the gate voltage of the MOS tube to control the on and off of the MOS tube, thereby controlling the switch of the charge and discharge circuit.

[0018] In some embodiments, the connection between the power connection unit and the first acquisition unit includes a positive input connection and a negative input connection.

[0019] By establishing a positive input connection and a negative input connection between the first acquisition unit 20 and the power connection unit, a safe and reliable connection can be established between the battery pack and the electronic device, and the battery status can be monitored and managed; this can ensure the safe operation of the battery pack, extend the service life of the battery, and improve the performance and stability of the electronic device.

[0020] In order to solve the above technical problems, the present application also provides a power transmission device, which includes a battery pack and a battery management system as described above, and the battery pack is connected to the power connection unit.

[0021] The beneficial effects of the present application are as follows: Different from the prior art, the present application discloses a secondary battery protection device and a secondary battery protection circuit, comprising a charging and discharging circuit, a first acquisition unit and a second acquisition unit; the current of the charging and discharging circuit is respectively acquired by the first and second acquisition units to determine whether there is an abnormality in the charging and discharging circuit, and to calculate whether the current difference between the first and second acquisition units meets the threshold value, thereby ensuring that both acquisition circuits can detect the fault of the charging and discharging circuit in time and control the protection unit on the charging and discharging circuit to disconnect the charging and discharging circuit, thereby protecting the circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative work, among which:

[0023] Figure 1This is a circuit structure diagram of an embodiment of a battery management system provided by the present application;

[0024] Figure 2 is a circuit structure diagram of another embodiment of a battery management system provided by the present application;

[0025] Figure 3 This is a circuit structure diagram of another embodiment of a battery management system provided by the present application. DETAILED DESCRIPTION

[0026] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only 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.

[0027] The terms "first", "second", "third" in the embodiments of the present application are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Thus, the features defined as "first", "second", "third" can expressly or implicitly include at least one of the features. In the description of the present application, the meaning of "multiple" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device comprising a series of steps or units is not limited to the listed steps or units, but optionally also includes steps or units that are not listed, or optionally also includes other steps or units inherent to these processes, methods, products or devices.

[0028] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0029] See also Figure 1 , Figure 1 1 is a circuit diagram of an embodiment of a battery management system provided by the present application, and the battery management system includes:

[0030] The charge and discharge circuit 10 comprises a first external terminal 11, a protection unit 12, a power connection unit 13, a voltage dividing unit 14 and a second external terminal 15 connected in series. The power connection unit 13 is used to connect a battery pack.

[0031] The battery pack is connected to the external circuit through the charge and discharge circuit 10 to provide power to the external circuit; when in use, the battery pack is installed in the power connection unit 13 of the charge and discharge circuit 10 to complete the connection between the battery pack and various parts of the battery management system.

[0032] The first acquisition unit 20, the first end of the first acquisition unit 20 is connected to the power connection unit 13, the second end of the first acquisition unit 20 is connected to the voltage divider unit 14, and the third end of the first acquisition unit 20 is connected to the protection unit 12. The first acquisition unit 20 is used to collect the first main circuit current flowing through the voltage divider unit 14, and control the protection unit 12 to disconnect the charge and discharge circuit 10 when the first main circuit current is greater than a preset current threshold.

[0033] Among them, the connection method between the power connection unit 13 and the first acquisition unit 20 in the charging and discharging circuit 10 depends on the type of the battery pack and the design of the first acquisition unit 20, including but not limited to: voltage measurement wiring method: connecting the positive and negative poles of the battery pack to the voltage measurement input port of the first acquisition unit 20; current measurement wiring method: connecting the positive and negative poles of the battery pack to the current measurement input port of the first acquisition unit 20; temperature measurement wiring method: connecting the temperature sensor of the battery pack to the temperature measurement input port of the first acquisition unit 20; communication interface wiring method: connecting the communication interface of the battery pack to the communication interface port of the first acquisition unit 20, usually using a serial communication interface (such as SPI, I2C) for data transmission.

[0034] The first acquisition unit 20 collects the voltage difference flowing through the two sides of the voltage divider unit 14 to calculate the current of the main circuit where the voltage divider unit 14 is located, and compares the calculated first main circuit current with a preset current threshold. If the first main circuit current is greater than the preset current threshold, there may be an abnormality in the current circuit, and the first acquisition unit 20 sends a control signal to the protection unit 12 to disconnect the charging and discharging circuit 10.

[0035] The current threshold can be set according to the power consumption of the actually installed battery pack and the voltage divider unit 14, and the current that does not exceed the current threshold range is the current when the circuit is operating normally.

[0036] A second acquisition unit 30, a first end of the second acquisition unit 30 is connected to the fourth end of the first acquisition unit 20, a second end of the second acquisition unit 30 is connected to the voltage divider unit 14, and a third end of the second acquisition unit 30 is connected to the protection unit 12, and the second acquisition unit 30 is used to collect the second main loop current flowing through the voltage divider unit 14, and control the protection unit 12 to disconnect the charge and discharge circuit 10 when the second main loop current is greater than the current threshold; wherein the second acquisition unit 30 further obtains the first main loop current and performs a difference operation on the first main loop current and the second main loop current, and controls the protection unit 12 to disconnect the charge and discharge circuit 10 when the obtained collection difference is greater than the preset difference threshold.

[0037] The second acquisition unit 30 calculates the current of the main circuit where the voltage divider unit 14 is located based on the voltage difference flowing through the two sides of the voltage divider unit 14, and compares the calculated second main circuit current with a preset current threshold. If the second main circuit current is greater than the preset current threshold, there may be an abnormality in the current circuit, and the second acquisition unit 30 sends a control signal to the protection unit 12 to disconnect the charging and discharging circuit 10.

[0038] Optionally, the electrical appliance selected by the second acquisition unit 30 when sampling the voltage of the voltage dividing unit 14 and the electrical appliance sampled by the first acquisition unit 20 may have a different voltage difference.

[0039] The second acquisition unit 30 also obtains the first main circuit current calculated by the first acquisition unit 20, and subtracts it from the second main circuit current to obtain a current difference. When the current difference is greater than a preset difference threshold, it indicates that the first acquisition unit 20 may have a fault and cannot timely feedback the status of the main circuit. The second acquisition unit 30 controls the protection unit 12 to disconnect the charging and discharging circuit 10.

[0040] See also Figure 2 , Figure 2 It is a circuit structure diagram of another embodiment of a battery management system provided by the present application.

[0041] Further, the first acquisition unit 20 includes a simulation unit 21 .

[0042] The analog unit 21 may be an AFE analog front end or an analog-to-digital / digital-to-analog converter. The analog unit 21 is used in the first acquisition unit 20 to measure parameters such as the voltage and current of the battery pack and to control the charging and discharging process of the battery pack.

[0043] For example, the AFE analog front end can collect analog signals such as voltage, current and temperature of each battery cell in the battery pack. After amplification, filtering and analog-to-digital conversion, these signals are converted into digital signals to provide a basis for data analysis and processing for the MCU. The performance of the AFE analog front end directly affects the accuracy and reliability of battery pack testing. The high-precision AFE can accurately measure subtle changes in battery cells, thereby promptly detecting abnormal conditions in the battery pack. In addition, the AFE also has the characteristics of high voltage resistance, low power consumption and anti-interference to meet the special requirements of battery pack testing.

[0044] Furthermore, the second acquisition unit 30 includes a microprocessor 31 .

[0045] The microprocessor 31 may be a MCU (microcontroller unit) or a PMIC (power management integrated circuit). The microprocessor 31 may be used alone or in combination with the analog unit 21 to implement monitoring, control and protection functions for the battery pack.

[0046] Furthermore, the voltage division unit 14 includes at least one resistor; when the voltage division includes multiple resistors, the multiple resistors are connected in series.

[0047] The voltage divider unit 14 is connected in series to the main circuit of the charge and discharge circuit 10, and is used to provide the first collection unit 20 and the second collection unit 30 with an electrical appliance for collecting the main circuit current. Optionally, the electrical appliance is a resistor. The voltage divider unit 14 may include a plurality of resistors connected in series, for example Figure 2 The resistors R1, R2, R3, etc. are connected in series.

[0048] By connecting the resistor in series to the main circuit, the voltage of the main circuit can be shared, and increasing the voltage difference across the voltage divider unit 14 can provide a suitable main circuit current value for other electrical appliances without changing the power supply.

[0049] Optionally, the resistor type includes: at least one of a fixed resistor, an adjustable resistor, a variable resistor, a current transformer, and a resistance-variable resistor.

[0050] Sampling resistors are important components for current detection and voltage measurement, and play a key role in circuit design. According to their structure and working principle, sampling resistors can include: Fixed resistors: the most common type of sampling resistors, with fixed resistance values. Usually made of metal or alloy materials, with stable resistance characteristics and high precision, fixed resistors can be used in applications such as current detection, voltage measurement, and power calculation; Adjustable resistors: also known as potentiometers, with the characteristics of adjustable resistance values, through mechanical structures such as knobs or sliders, the resistance value can be adjusted to meet different circuit requirements, and adjustable resistors are often used to adjust parameters such as circuit gain, bias, and sensitivity; Variable resistors: a component that can adjust the resistance value according to external conditions or signals. Variable resistors can adjust the resistance value according to input signals, temperature, or other parameters, and are often used in circuits such as sensors, regulators, and filters; Current transformers: Current transformers are a special type of sampling resistor used to measure current. It measures the current in the circuit through the principle of electromagnetic induction, usually consists of an iron core and multiple turns of coil, and outputs a voltage signal proportional to the current; Variable resistor: also known as varistor or photoresistor, is a component whose resistance value changes with external conditions. Variable resistor can change its resistance value according to external conditions such as light, temperature, and pressure, and is commonly used in applications such as photosensitive sensors, temperature sensors, and pressure sensors.

[0051] By flexibly matching and using various types of resistors, the voltage divider unit can provide a variety of different sampling resistance values ​​while dividing the voltage for the charging and discharging circuit, so that the first and second acquisition units can sample multiple times at different resistance values, thereby improving the numerical accuracy of the first and second main circuit currents.

[0052] Optionally, the protection unit 12 includes a MOS tube 122 and a driving chip 121; the MOS tube 122 is an enhanced MOS tube 122, which is used to connect or disconnect the charging and discharging circuit 10; the driving chip 121 is connected to the gate of the MOS tube 122, and is used to receive the control signal of the acquisition unit and control the MOS tube 122.

[0053] The driving chip 121 is connected to the first acquisition unit 20 and the second acquisition unit 30 , and is used to obtain control signals sent by the acquisition units and control the switch circuit of the MOS tube 122 .

[0054] The source and drain of the MOS tube 122 are connected in series to the main circuit of the charge and discharge circuit 10, and the gate is connected to the driving chip 121. The MOS tube 122 is used as an electric control switch of the main circuit of the switch charge and discharge circuit 10. When the driving chip 121 receives the control signal sent from the first acquisition unit 20 or the second acquisition unit 30, the power supply current of the gate of the MOS tube 122 is disconnected, and the gate of the enhanced MOS tube 122 loses the power supply current, and the connection between the source and the drain is disconnected. At this time, the main circuit of the charge and discharge circuit 10 is disconnected.

[0055] By controlling the switch of the MOS tube 122 through the driving chip 121, the main circuit can be disconnected in time when a circuit fails, so as to avoid abnormal power supply damaging other power supplies or electrical appliances on the circuit, thereby protecting the charging and discharging circuit and the battery pack.

[0056] Optionally, see Figure 3 , Figure 3 This is a circuit structure diagram of another embodiment of a battery management system provided by the present application. The driving chip 121 may include: a first control input terminal 123, used to receive a control signal sent by a first acquisition unit; a second control input terminal 123, used to receive a control signal sent by a second acquisition unit; a signal processing circuit 122, connected to the first control input terminal and the second control terminal, used to process and decode the signal obtained by the control input terminal, and generate a level control signal for driving the gate of the MOS tube; a control output terminal 125, connected to the signal processing circuit, used to output the level signal generated by the signal processing circuit, and control the MOS tube to be turned on or off.

[0057] The driver chip controls the gate voltage of the MOS tube to control the on and off of the MOS tube, thereby controlling the switch of the charge and discharge circuit.

[0058] Furthermore, the connection between the power connection unit 13 and the first acquisition unit 20 includes a positive input connection and a negative input connection.

[0059] The first acquisition unit 20 can monitor the status parameters of the battery pack through the positive input connection and the negative input connection, including the voltage, current, temperature and other parameters of the battery pack, and monitor the battery status in real time to ensure the safe operation of the battery pack and extend the life of the battery; the first acquisition unit 20 can also monitor the overcharge, over-discharge, short circuit and other conditions of the battery pack. When an abnormal condition occurs in the battery pack, the connection between the battery pack and the electronic device can be cut off in time to protect the safety of the battery and the equipment; the first acquisition unit 20 converts the analog signal output by the battery pack into a digital signal to facilitate processing and analysis by a microprocessor or controller.

[0060] The driver chip controls the gate voltage of the MOS tube to control the on and off of the MOS tube, thereby controlling the switch of the charge and discharge circuit.

[0061] The first acquisition unit 20 is connected to the battery pack through the power connection unit 13, and collects parameters such as the voltage of the battery pack. When connecting the first acquisition unit 20 to the power connection unit 13, different connection methods can be selected to adapt the battery pack according to actual needs. For example, series connection will increase the total voltage, while parallel connection will increase the total current capacity. Some common connection methods include: Series connection: connect the positive and negative electrodes of multiple battery cells to form a series battery pack, connect the positive electrode of the battery pack to the positive input connection, and connect the negative electrode of the battery pack to the negative input connection; when connecting in series, it is necessary to ensure that the voltage and capacity of each battery cell are similar to avoid voltage imbalance and over-discharge / overcharge problems. Parallel connection: connect the positive electrodes of multiple battery cells to the positive electrodes, and the negative electrodes to the negative electrodes to form a parallel battery pack, connect the positive electrode of the battery cell at one end to the positive input connection, and connect the negative electrode of the battery cell at the other end to the negative input connection. Parallel connection can increase the total capacity and improve the discharge capacity of the battery pack. Mixed connection: Sometimes a mixed connection of series and parallel can be used to connect multiple battery cells according to specific design requirements to balance the total voltage and total capacity.

[0062] When the battery pack contains multiple battery cells, the power connection unit corresponds to multiple connection modes for connecting to the first acquisition unit 20 to realize monitoring and management of the entire battery pack. The connection mode is multi-channel connection: the positive and negative poles of each battery cell are connected to the independent channel of the AFE analog front end, and the voltage of each battery cell is monitored simultaneously through multiple channels. This connection mode can realize independent monitoring and management of each battery cell and more accurately control the state of the battery pack; multiple battery cells are connected into a chain, and then the two ends of the chain are connected to the two channels of the first acquisition unit, and the voltage of the entire battery pack is monitored by series connection. This connection mode is suitable for the case where the number of battery cells is large, and the number of connection lines can be reduced; balanced connection: a balanced connection circuit is added between multiple battery cells to monitor and adjust the voltage of each battery cell to ensure the voltage balance between each battery cell. Balanced connection can help improve the performance and safety of the battery pack.

[0063] Choosing the right connection method depends on the configuration of the battery pack, monitoring requirements and system design, and needs to comprehensively consider factors such as voltage monitoring accuracy, number of channels, number of connection lines, etc. Through a reasonable connection method, effective monitoring and management of multiple battery cells can be achieved to ensure the safe and stable operation of the battery pack.

[0064] For example, when each battery cell of the battery pack is connected to the first acquisition unit 20, the positive electrode of each battery cell needs to be connected to the port of the first acquisition unit 20, and the positive input connection of the power connection unit 13 and the first acquisition unit 20 is connected by a bus. At the same time, when connecting multiple battery cells, it is necessary to ensure that the connection between the battery cells is reliable to avoid poor contact or short circuit; use a balancing circuit to monitor and adjust the voltage between each battery cell to ensure voltage balance; use a protection circuit to prevent the battery pack from overcharging, over-discharging, short circuit, etc., to ensure the safety of the battery pack.

[0065] Establishing a positive input connection and a negative input connection between the first acquisition unit 20 and the power connection unit can establish a safe and reliable connection between the battery pack and the electronic device, and realize the monitoring and management of the battery status; this can ensure the safe operation of the battery pack, extend the service life of the battery, and improve the performance and stability of the electronic device.

[0066] The present application also provides a power transmission device, which includes a battery pack and the above-mentioned battery management system, and the battery pack is connected to the power connection unit 13. The power transmission device can be an independent device or module, or a part of the system circuit.

[0067] Different from the prior art, the present application provides a battery management system and a power transmission device, comprising a first external terminal, a protection unit, a power connection unit, a voltage divider unit and a second external terminal connected in series on a charging and discharging circuit, and a first collection unit and a second collection unit; the first and second collection units collect the voltage on the voltage divider unit to calculate the main loop current of the charging and discharging circuit, compare the collected main loop current value with a preset current threshold, judge whether there is an abnormality in the current main loop, and complete the first level of protection for the battery; make a difference between the main loop currents collected by the first and second collection units, and compare it with the preset difference threshold, and judge for the second time whether the collection unit and the main loop are normal, so as to avoid the failure of the main loop to be discovered in time due to the failure of the collection unit, complete the second level of protection for the battery, and improve the reliability of the battery protection circuit.

[0068] The various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referenced to each other, and each embodiment focuses on the differences from other embodiments.

[0069] The method provided in the present application can be used in many general or special computing system environments or configurations, such as personal computers, server computers, handheld or portable devices, tablet devices, multiprocessor systems, microprocessor-based systems, set-top boxes, programmable consumer electronic devices, network PCs, minicomputers, mainframe computers, and distributed computing environments including any of the above systems or devices.

[0070] In the several embodiments provided in this application, it should be understood that the disclosed methods and devices can be implemented in other ways. For example, the device embodiments described above are only illustrative, for example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not performed.

[0071] The above descriptions are merely embodiments of the present application and are not intended to limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A battery management system, characterized in that: The battery management system comprises: The charging and discharging circuit comprises a first external terminal, a protection unit, a power connection unit, a voltage dividing unit and a second external terminal connected in series, wherein the power connection unit is used to connect a battery pack; a first acquisition unit, wherein a first end of the first acquisition unit is connected to the power connection unit, a second end of the first acquisition unit is connected to the voltage divider unit, and a third end of the first acquisition unit is connected to the protection unit, the first acquisition unit is used to acquire a first main circuit current flowing through the voltage divider unit, and control the protection unit to disconnect the charge and discharge circuit when the first main circuit current is greater than a preset current threshold; a second collection unit, wherein a first end of the second collection unit is connected to a fourth end of the first collection unit, a second end of the second collection unit is connected to the voltage divider unit, a third end of the second collection unit is connected to the protection unit, and the second collection unit is used to collect a second main loop current flowing through the voltage divider unit, and control the protection unit to disconnect the charge and discharge circuit when the second main loop current is greater than the current threshold; The second acquisition unit further acquires the first main circuit current and performs a difference operation on the first main circuit current and the second main circuit current, and controls the protection unit to disconnect the charge and discharge circuit when the acquired acquisition difference is greater than a preset difference threshold.

2. The battery management system according to claim 1, characterized in that: The first acquisition unit includes a simulation unit.

3. The battery management system according to claim 1, characterized in that: The second acquisition unit includes a microprocessor.

4. The battery management system according to claim 1, characterized in that: The voltage dividing unit includes at least one resistor; When the voltage dividing unit includes a plurality of resistors, the plurality of resistors are connected in series.

5. The battery management system according to claim 4, characterized in that: The resistor type includes: at least one of a fixed resistor, an adjustable resistor, a variable resistor, a current transformer, and a resistance-variable resistor.

6. The battery management system according to claim 1, characterized in that: The protection unit includes a MOS tube and a driving chip; The source and drain of the MOS tube are connected in series to the main loop of the charge and discharge circuit, so as to switch on or off the charge and discharge circuit; The driving chip is connected to the gate of the MOS tube and to the first acquisition unit and the second acquisition unit, and is used to receive control signals of the first acquisition unit and the second acquisition unit and control the switch of the MOS tube.

7. The battery management system according to claim 6, characterized in that: The driver chip comprises: A first control input terminal, used to receive a control signal sent by the first acquisition unit; A second control input terminal, used for receiving a control signal sent by the second acquisition unit; A signal processing circuit, connected to the first control input terminal and the second control input terminal, and used for processing and decoding the signal obtained by the control input terminal to generate a level control signal for driving the gate of the MOS tube; The control output terminal is connected to the signal processing circuit and is used to output the level signal generated by the signal processing circuit to control the MOS tube to be turned on or off.

8. The battery management system according to claim 1, characterized in that: The connection between the power connection unit and the first acquisition unit includes a positive input connection and a negative input connection, and the positive input connection and the negative input connection are used to provide the voltage parameter of the battery pack to the first acquisition unit.

9. A power transmission device, characterized in that: The power transmission device comprises a battery pack and a battery management system according to any one of claims 1 to 8, and the battery pack is connected to the power connection unit.

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