Battery management system and energy storage system

Abstract

The utility model relates to a battery management system and an energy storage system, the battery management system comprises an undervoltage activation circuit, a power supply control circuit, a charge and discharge circuit and a controller, when an energy storage battery is in undervoltage or low voltage, an external power supply is input, and the undervoltage activation circuit outputs an activation signal to the power supply control circuit; the external power supply supplies power to the controller, so that the controller is in a power-on state; the controller outputs a driving signal to the charging and discharging circuit; the charging and discharging circuit connects the electrical connection between the external power supply and the energy storage battery; and the external power supply charges the energy storage battery. Under the condition of power shortage of the energy storage battery, the energy storage system supplements power to the energy storage battery through the external power supply, the external power supply supplies power to the controller, the controller is activated, and then the controller controls the process that the external power supply supplements power to the energy storage battery, so that the power supplementation process is monitored, and the power supplementation safety of the energy storage battery is improved.

Description

Technical Field

[0001] This utility model relates to the field of battery management systems, and in particular to a battery management system and an energy storage system. Background Technology

[0002] If the energy storage battery in the energy storage system is depleted or has a low voltage, it will shorten the battery life, affect the battery charging and discharging performance, and increase safety hazards. Therefore, it is necessary to replenish the energy storage battery in a timely manner.

[0003] The energy storage battery also supplies power to the battery management system (BMS), enabling the BMS to function properly. If the energy storage battery is depleted or its voltage drops below the BMS's startup voltage, the BMS will malfunction and be unable to control external power to replenish the battery. If the energy storage battery is replenished solely by an external power source, it will be difficult to monitor effectively, increasing the risk of overcharging or overheating without timely power-off protection, resulting in low safety during the replenishment process. Utility Model Content

[0004] The present invention aims to provide a battery management system and an energy storage system that can improve the safety of external power supply for replenishing energy storage batteries.

[0005] To solve the above-mentioned technical problems, the present invention provides the following technical solutions:

[0006] In a first aspect, embodiments of the present invention provide a battery management system, the battery management system comprising: a low-power activation circuit, a power control circuit, a charging and discharging circuit, and a controller;

[0007] The power depletion activation circuit is electrically connected to both the external power supply and the power control circuit. The power depletion activation circuit is used to respond to the input of the external power supply and output an activation signal to the power control circuit.

[0008] The power control circuit is electrically connected to the external power supply and the power supply terminal of the controller, respectively. The power control circuit is used to respond to the input of the activation signal and connect the power supply terminal of the external power supply and the power supply terminal of the controller.

[0009] The output terminal of the controller is electrically connected to the charging and discharging circuit, which is also electrically connected to the energy storage battery and the external power supply. The controller is used to output a drive signal to the charging and discharging circuit when powered on.

[0010] The charging and discharging circuit is used to respond to the input of the driving signal and connect the external power supply to the energy storage battery, so as to control the external power supply to charge the energy storage battery.

[0011] In some embodiments, the power depletion activation circuit includes a first detection unit, a first switching unit, and a voltage divider unit;

[0012] The first detection unit is electrically connected to the control terminal of the first switch unit at the first node. The first detection unit is also electrically connected to the external power supply. The first detection unit is used to respond to the input of the external power supply and output a conduction signal to the first node.

[0013] The first switching unit is also electrically connected to the external power supply and the voltage divider unit respectively. The first switching unit is used to respond to the input of the conduction signal and connect the electrical connection between the external power supply and the voltage divider unit.

[0014] The voltage divider unit is also electrically connected to the power control circuit at the second node. The voltage divider unit is used to divide the external power supply and output the activation signal to the power control circuit through the second node.

[0015] In some embodiments, the first detection unit includes a first resistor, a second resistor, a third resistor, and a first Zener diode;

[0016] The negative terminal of the external power supply is connected to the anode of the first Zener diode and one end of the third resistor, respectively. The cathode of the first Zener diode is connected to one end of the first resistor. The other end of the first resistor, one end of the second resistor, and the control terminal of the first switching unit are connected to the first node. The other end of the second resistor is connected to the positive terminal of the external power supply.

[0017] In some embodiments, the first switching unit includes a first diode and a first transistor;

[0018] The anode of the first diode, the base of the first transistor, and the first detection unit are electrically connected to the first node. The cathode of the first diode and the emitter of the first transistor are connected to the positive terminal of the external power supply. The collector of the first transistor is electrically connected to the voltage divider unit.

[0019] In some embodiments, the voltage divider unit includes a second Zener diode, a fourth resistor, and a third Zener diode;

[0020] The cathode of the second Zener diode is electrically connected to the first switching unit, the anode of the second Zener diode is connected to one end of the fourth resistor, the other end of the fourth resistor is electrically connected to the cathode of the third Zener diode and the power control circuit at the second node, and the anode of the third Zener diode is grounded.

[0021] In some embodiments, the power depletion activation circuit further includes a second detection unit;

[0022] The second detection unit is electrically connected to the second node and the controller respectively. The second detection unit is used to respond to the input of the activation signal and output the detection signal to the controller.

[0023] The controller is also configured to respond to the input of the detection signal and output the drive signal to the charging and discharging circuit.

[0024] In some embodiments, the second detection unit includes a fifth resistor, a first MOSFET, a sixth resistor, and a seventh resistor;

[0025] One end of the fifth resistor is electrically connected to the gate of the first MOS transistor and the voltage divider unit at the second node. The other end of the fifth resistor is grounded together with the source of the first MOS transistor. The drain of the first MOS transistor is electrically connected to one end of the sixth resistor and one end of the seventh resistor. The other end of the sixth resistor is connected to a DC power supply. The other end of the seventh resistor is connected to the controller.

[0026] In some embodiments, the power control circuit includes a second switching unit and a third switching unit;

[0027] The input terminal of the second switching unit is electrically connected to the power depletion activation circuit, and the output terminal of the second switching unit is electrically connected to the control terminal of the third switching unit at the third node. The second switching unit is used to respond to the input of the activation signal and output a control signal to the third switching unit.

[0028] The third switching unit is also electrically connected to the external power supply and the input terminal of the power conversion circuit, respectively. The third switching unit is used to respond to the input of the control signal and connect the external power supply and the power supply terminal of the controller.

[0029] In some embodiments, the second switching unit includes an eighth resistor, a ninth resistor, a tenth resistor, a second transistor, and a fourth Zener diode;

[0030] One end of the eighth resistor and one end of the tenth resistor are connected to the depletion activation circuit. The other end of the eighth resistor, the anode of the fourth Zener diode, one end of the ninth resistor, and the emitter of the second transistor are all grounded. The other end of the tenth resistor is connected to the cathode of the fourth Zener diode, the other end of the ninth resistor, and the base of the second transistor. The collector of the second transistor is electrically connected to the control terminal of the third switching unit at the third node.

[0031] In some embodiments, the third switching unit includes a twelfth resistor, a thirteenth resistor, a fourteenth resistor, a third transistor, a fourth transistor, and a second diode;

[0032] One end of the twelfth resistor is electrically connected to the second switching unit at the third node. The other end of the twelfth resistor is connected to the base of the third transistor and one end of the thirteenth resistor. The emitter of the third transistor is connected to the base of the fourth transistor. The collector of the third transistor is connected to one end of the fourteenth resistor. The other end of the fourteenth resistor is electrically connected to the collector of the fourth transistor and the power conversion circuit. The emitter of the fourth transistor is connected to the other end of the thirteenth resistor and the cathode of the second diode. The anode of the second diode is connected to the positive terminal of the external power supply.

[0033] In some embodiments, the charging and discharging circuit includes a charging MOSFET and a discharging MOSFET;

[0034] The gate of the charging MOSFET is used to receive the drive signal, the source of the charging MOSFET is connected to the negative terminal of the external power supply, the drain of the charging MOSFET is connected to the drain of the discharging MOSFET, the source of the MOSFET is connected to the negative terminal of the energy storage battery, and the positive terminal of the energy storage battery is connected to the positive terminal of the external power supply.

[0035] In some embodiments, the battery management system further includes a power conversion circuit;

[0036] The input terminal of the power conversion circuit is used to connect to the external power source, and the output terminal of the power conversion circuit is electrically connected to the power supply terminal of the controller. The power conversion circuit is used to convert the external power source into the power supply for the controller.

[0037] In a second aspect, embodiments of the present invention provide an energy storage system, including an energy storage battery, an external power source, and a battery management system as described above.

[0038] In various embodiments of this utility model, the battery management system includes a low-charge activation circuit, a power control circuit, a charge / discharge circuit, and a controller. The low-charge activation circuit is electrically connected to both an external power source and the power control circuit. The power control circuit is electrically connected to both the external power source and the power supply terminal of the controller. The output terminal of the controller is electrically connected to the charge / discharge circuit, which is also electrically connected to both the energy storage battery and the external power source. When the energy storage battery is low-charged or has a low voltage, an external power source is input. The low-charge activation circuit outputs an activation signal to the power control circuit, thereby connecting the power supply terminal of the external power source and the controller. The external power source supplies power to the controller, putting it into a powered-on state. The controller outputs a drive signal to the charge / discharge circuit, connecting the external power source and the energy storage battery. The external power source charges the energy storage battery to replenish its power. When the energy storage battery is depleted, the energy storage system replenishes the battery with an external power source. The external power source also supplies power to the controller, which activates the controller and then controls the process of replenishing the battery with the external power source. This allows for monitoring of the replenishment process and improves the safety of replenishing the energy storage battery. Attached Figure Description

[0039] One or more embodiments are illustrated by way of example with reference numerals in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Elements with the same reference numerals in the drawings are denoted as similar elements. Unless otherwise stated, the figures in the drawings are not to be limited by scale.

[0040] Figure 1 This is a schematic diagram of the structure of one of the energy storage systems provided in this embodiment of the utility model;

[0041] Figure 2 This is a schematic diagram of the structure of one of the battery management systems provided in this utility model embodiment;

[0042] Figure 3 This is a schematic diagram of the structure of one of the battery management systems provided in this utility model embodiment;

[0043] Figure 4 This is a schematic diagram of the structure of one of the battery management systems provided in this utility model embodiment;

[0044] Figure 5 This is a schematic diagram of the circuit structure of one of the depleted laser circuits provided in this embodiment of the utility model;

[0045] Figure 6 This is a schematic diagram of the circuit structure of one of the power control circuits provided in this embodiment of the utility model;

[0046] Figure 7This is a schematic diagram of the circuit structure of one of the charging and discharging circuits provided in this embodiment of the present invention. Detailed Implementation

[0047] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this utility model and are not intended to limit this utility model.

[0048] Please see Figure 1 , Figure 1 This is a schematic diagram of the structure of an energy storage system provided in an embodiment of this utility model, as shown below. Figure 1 As shown, the energy storage system includes an energy storage battery 20, an external power supply 30, and a battery management system 10. The energy storage battery 20 is a battery module comprising multiple cells connected in parallel, series, or a hybrid configuration for storing and supplying electrical energy. The hybrid configuration includes both series and parallel connections. The energy storage battery 20 supplies power to a load, which is any electrical energy-consuming device, including: electric vehicles such as electric cars, electric two-wheelers, and electric tricycles; power tools; and various household appliances such as refrigerators and washing machines.

[0049] The energy storage battery 20 is electrically connected to the battery management system 10 (BMS), and the two together form a battery pack. The battery management system 10 monitors the status of the energy storage battery 20. Its main function is to intelligently manage and maintain each energy storage battery 20 unit, prevent the energy storage battery 20 from overcharging, over-discharging, and exceeding the limits of high and low temperatures, and greatly improve the safety and lifespan of the energy storage battery 20.

[0050] If the energy storage battery 20 experiences deep discharge during use, lithium ions inside the battery will remain on the negative electrode plate for an extended period, resulting in passivation and capacity decay. This may lead to a state of low charge or low battery voltage. A low charge in the energy storage battery 20 will shorten its lifespan, affect its charge and discharge performance, and increase safety hazards. Therefore, it is necessary to replenish the energy storage battery 20 promptly.

[0051] The energy storage battery 20 also supplies power to the battery management system 10, enabling the battery management system 10 to function properly. If the energy storage battery 20 is depleted or its voltage drops below the starting voltage of the battery management system 10, the battery management system 10 will not function properly and will be unable to control the external power supply 30 to replenish the energy storage battery 20. If the external power supply 30 replenishes the energy storage battery 20 independently, the energy storage battery 20 will not be effectively monitored, and there is a risk of overcharging or overheating without timely power-off protection, resulting in low safety during the replenishment process.

[0052] Based on the above reasons, this utility model embodiment provides a battery management system that can control an external power source 30 to replenish the energy storage battery 20 when the energy storage battery 20 is depleted or the battery voltage is low, and monitor the replenishment process to improve the safety of the replenishment process.

[0053] Specifically, such as Figure 2 As shown, the battery management system 10 includes a low-power activation circuit 11, a power control circuit 12, a charge / discharge circuit 13, and a controller 14. The low-power activation circuit 11 is electrically connected to the external power supply 30 and the power control circuit 12. The power control circuit 12 is electrically connected to the external power supply 30 and the power supply terminal of the controller 14. The output terminal of the controller 14 is electrically connected to the charge / discharge circuit 13. The charge / discharge circuit 13 is also electrically connected to the energy storage battery 20 and the external power supply 30.

[0054] When the energy storage battery 20 is depleted or has a low voltage, the external power supply 30 is input, and the depletion activation circuit 11 outputs an activation signal to the power control circuit 12. As a result, the power control circuit 12 connects the power supply terminal of the external power supply 30 and the controller 14, and the external power supply 30 supplies power to the controller 14, so that the controller 14 is in the power-on state. The controller 14 outputs a drive signal to the charging and discharging circuit 13, and the charging and discharging circuit 13 connects the external power supply 30 and the energy storage battery 20. The external power supply 30 charges the energy storage battery 20 to replenish its power.

[0055] In some embodiments, the external power supply 30 may be the power output from the DC-DC circuit in a device such as an uninterruptible power supply, an energy storage converter, or an inverter.

[0056] An uninterruptible power supply (UPS) is a type of power supply that includes an energy storage device. UPSs are primarily used to provide uninterrupted power to equipment with high power stability requirements. When the mains input is normal, the UPS stabilizes the mains voltage and supplies it to the load. In this state, the UPS functions as an AC voltage regulator while simultaneously charging its energy storage battery. When the mains power is interrupted (power outage), the UPS immediately transfers the DC power from the energy storage battery to the load via an inverter, continuing to supply 220V AC power. This ensures the load continues to operate normally and protects the load's hardware and software from damage.

[0057] The energy storage battery provides DC power to the power conversion system (PCS), which converts the DC power to AC power and outputs this AC power through its AC connection terminal to the power grid and / or load, thus supplying power to the grid and / or load and discharging the energy storage battery. The power conversion system can also convert AC power from the grid to DC power and output this DC power through its DC connection terminal to the energy storage battery, where it stores energy and charges the battery.

[0058] Therefore, uninterruptible power supplies, energy storage converters, and inverters all include DC-DC circuits, which are used to convert direct current (DC) to the required DC voltage. External power supply 30 provides DC output from the DC-DC circuit.

[0059] It should be noted that the external power supply 30 can be output from the DC-DC circuit in the uninterruptible power supply, energy storage converter, or inverter equipment in the energy storage system, or it can be output from the DC-DC circuit in a separate uninterruptible power supply, energy storage converter, or inverter equipment.

[0060] In some embodiments, the controller 14 is a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), a microcontroller, an ARM (Acorn RISC Machine) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination of these components.

[0061] Therefore, when the energy storage battery is depleted, the energy storage system replenishes the battery with an external power source. The external power source also supplies power to the controller, which activates the controller. The controller then controls the process of replenishing the battery with the external power source, thereby monitoring the replenishment process and improving the safety of replenishing the energy storage battery.

[0062] Please see Figure 3 , Figure 3 This is a schematic diagram of the structure of a battery management system provided in an embodiment of the present invention, as shown below. Figure 3 As shown, the power depletion activation circuit 11 includes a first detection unit 111, a first switching unit 112, and a voltage divider unit 113. The control terminals of the first detection unit 111 and the first switching unit 112 are electrically connected to the first node A. The first detection unit 111 is also electrically connected to the external power supply 30. The first switching unit 112 is also electrically connected to the external power supply 30 and the voltage divider unit 113, respectively. The voltage divider unit 113 is also electrically connected to the power control circuit 12 to the second node B.

[0063] When the energy storage battery 20 is depleted or has a low battery voltage, the external power supply 30 is connected to the first detection unit 111. The first detection unit 111 detects the input of the external power supply 30 and outputs a conduction signal to the first node A. This conduction signal acts on the control terminal of the first switching unit 112, causing the first switching unit 112 to be in a conducting state, thereby connecting the external power supply 30 and the voltage divider unit 113.

[0064] Voltage divider unit 113 divides the voltage of external power supply 30 and generates a voltage divider signal at the second node B. This voltage divider signal acts as an activation signal and acts on power control circuit 12, so that power control circuit 12 responds to the input of the activation signal and connects the power supply terminal of external power supply 30 and controller 14, thereby enabling external power supply 30 to supply power to controller 14, and controller 14 to be in a powered-on state.

[0065] After the controller 14 is powered on, it outputs a drive signal to the charging and discharging circuit 13, controls the charging and discharging circuit 13 to be in the conducting state, connects the external power supply 30 and the energy storage battery 20, and then controls the external power supply 30 to charge the energy storage battery 20.

[0066] In some embodiments, the first switching unit 112 can be various controllable switches such as relays or IGBTs, which can be determined according to the actual application scenario. The first switching unit 112 can receive a conduction signal at its control terminal, which can control the conduction of the first switching unit 112.

[0067] In some embodiments, the voltage divider unit 113 can be a resistor voltage divider, a capacitor voltage divider, a transformer voltage divider, or a voltage regulator circuit formed by combining a Zener diode and a resistor, which can be determined according to the actual application scenario.

[0068] Please continue reading. Figure 3 The power depletion activation circuit 11 also includes a second detection unit 114. The second detection unit 114 is electrically connected to the second node B and the controller 14. The activation signal output by the voltage divider unit 113 through the second node B also acts on the second detection unit 114. When the second detection unit 114 detects the input of the activation signal, it outputs a detection signal to the controller 14, indicating that the power depletion activation circuit 11 has activated the controller 14 and the controller 14 is in a powered-on state. When the controller 14 receives the detection signal, it outputs a drive signal to the charging and discharging circuit 13, controls the charging and discharging circuit 13 to be in a conducting state, connects the external power supply 30 and the energy storage battery 20, and then controls the external power supply 30 to charge the energy storage battery 20.

[0069] When the controller 14 is powered on and receives a detection signal, it indicates that the controller 14 can monitor the charging process of the energy storage battery 20. The controller 14 drives the charging and discharging circuit 13 to be in the conducting state, thereby enabling the external power supply 30 to charge the energy storage battery 20. The charging process is monitored and controlled by the controller 14.

[0070] In some embodiments, please continue reading Figure 3 The power control circuit 12 includes a second switch unit 121 and a third switch unit 122. The input terminal of the second switch unit 121 is electrically connected to the power depletion activation circuit 11. The output terminal of the second switch unit 121 is electrically connected to the control terminal of the third switch unit 122 at the third node C. The third switch unit 122 is also electrically connected to the power supply terminals of the external power supply 30 and the controller 14, respectively.

[0071] When the external power supply 30 is input, the voltage divider unit 113 outputs an activation signal through the second node B. The activation signal acts on the control terminal of the second switch unit 121, changing the state of the second switch unit 121 to make it in the conducting state, and generating a control signal at the third node C.

[0072] The control signal acts on the control terminal of the third switch unit 122, changing the state of the third switch unit 122 to make it in the conducting state, connecting the power supply terminal of the external power supply 30 and the controller 14, so that the external power supply 30 supplies power to the controller 14, and the controller 14 is powered on and works normally.

[0073] In this embodiment of the invention, the second switching unit 121 drives the working state of the third switching unit 122, and the third switching unit 122 controls the electrical connection between the external power supply 30 and the power supply terminal of the controller 14, thereby achieving electrical isolation and flexible control. For example, the electrical connection between the external power supply 30 and the power supply terminal of the controller 14 can be remotely or automatically controlled. Furthermore, using multiple switching units can increase the redundancy of the entire battery management system 10 and improve the overall reliability.

[0074] In some embodiments, both the second switching unit 121 and the third switching unit 122 can be various controllable switches such as relays or IGBTs, which can be determined according to the actual application scenario. The second switching unit 121 can receive an activation signal at its control terminal, which can control the conduction of the second switching unit 121. The third switching unit 122 can receive a control signal at its control terminal, which can control the conduction of the third switching unit 122.

[0075] In some embodiments, please refer to Figure 4 , Figure 4 This is a schematic diagram of the structure of a battery management system provided in an embodiment of the present invention, as shown below. Figure 4 As shown, the battery management system 10 also includes a power conversion circuit 15. The input terminal of the power conversion circuit 15 is used to connect to an external power source 30, and the output terminal of the power conversion circuit 15 is electrically connected to the power supply terminal of the controller 14.

[0076] When the charging / discharging circuit 13 is in the conducting state, the electrical connection between the external power supply 30 and the power conversion circuit 15 is established. The external power supply 30 is connected to the input terminal of the power conversion circuit 15, which converts the external power supply 30 into a power supply for the controller 14. The conversion by the power conversion circuit 15 is generally a step-down conversion, which reduces the voltage of the external power supply 30 to obtain the voltage of the power supply, such as +12V, +5V, or +3.3V. The specific voltage can be set according to the needs of the controller 14.

[0077] In some embodiments, please continue reading Figure 4 The battery management system 10 also includes an isolation circuit 16, which is electrically connected to the controller 14 and the charging and discharging circuit 13 respectively. The isolation circuit 16 isolates the controller 14 and the charging and discharging circuit 13. When the controller 14 sends a drive signal, the drive signal passes through the isolation circuit 16 and then acts on the charging and discharging circuit 13 to control the working state of the charging and discharging circuit 13.

[0078] Electrical isolation is achieved between the charging / discharging circuit 13 and the controller 14 through the isolation circuit 16. The isolation circuit 16 separates the output of the controller 14 from the input of the charging / discharging circuit 13 and effectively isolates interference signals from other circuits or the environment, preventing false triggering and improving the reliability and stability of the system.

[0079] Please see Figure 5 , Figure 5 This is a schematic diagram of the circuit structure of a power depletion activation circuit provided in an embodiment of the present invention. The first detection unit 111 includes a first resistor R1, a second resistor R2, a third resistor R3, and a first Zener diode ZD1. The negative terminal V- of the external power supply is connected to the anode of the first Zener diode ZD1 and one end of the third resistor R3, respectively. The cathode of the first Zener diode ZD1 is connected to one end of the first resistor R1. The other end of the first resistor R1, one end of the second resistor R2, and the control terminal of the first switching unit 112 are connected to the first node A. The other end of the second resistor R2 is connected to the positive terminal V+ of the external power supply.

[0080] The first switching unit 112 includes a first diode D1 and a first transistor Q1. The anode of the first diode D1, the base of the first transistor Q1, and the first detection unit 111 are electrically connected to the first node A. Specifically, the anode of the first diode D1, the base of the first transistor Q1, the second resistor R2, and the first resistor R1 are electrically connected to the first node A. The cathode of the first diode D1 and the emitter of the first transistor Q1 are connected to the positive terminal V+ of the external power supply. The collector of the first transistor Q1 is electrically connected to the voltage divider unit 113.

[0081] The voltage divider unit 113 includes a second Zener diode ZD2, a fourth resistor R4, and a third Zener diode ZD3. The cathode of the second Zener diode ZD2 is electrically connected to the first switching unit 112. Specifically, the cathode of the second Zener diode ZD2 is connected to the collector of the first transistor Q1. The anode of the second Zener diode ZD2 is connected to one end of the fourth resistor R4. The other end of the fourth resistor R4 is electrically connected to the cathode of the third Zener diode ZD3 and the power control circuit 12 at the second node B. The anode of the third Zener diode ZD3 is grounded to GND.

[0082] The second detection unit 114 includes a fifth resistor R5, a first MOSFET Q2, a sixth resistor R6, and a seventh resistor R7. One end of the fifth resistor R5 is electrically connected to the gate of the first MOSFET Q2 and the voltage divider unit 113 at the second node B. The other end of the fifth resistor R5 is grounded to GND along with the source of the first MOSFET Q2. The drain of the first MOSFET Q2 is electrically connected to one end of the sixth resistor R6 and one end of the seventh resistor R7. The other end of the sixth resistor R6 is connected to a DC power supply, and the other end of the seventh resistor R7 is connected to the controller 14. The voltage of the DC power supply is +3.3V.

[0083] When the external power supply 30 is connected, the positive terminal V+ of the external power supply, through the second resistor R2 and the first resistor R1, reversely breaks down the first Zener diode ZD1 to the negative terminal V- of the external power supply. The conduction circuit is: positive terminal V+ of the external power supply → second resistor R2 → first resistor R1 → first Zener diode ZD1 → negative terminal V- of the external power supply. A conduction signal is generated at the first node A. The voltage of the conduction signal is the voltage of the external power supply 30 divided across the second resistor R2, and the voltage of the conduction signal is less than the voltage of the external power supply 30. Consequently, the first transistor Q1 conducts, connecting the positive terminal V+ of the external power supply with the cathode of the second Zener diode ZD2.

[0084] The positive terminal V+ of the external power supply reversely breaks down the second Zener diode ZD2 and the third Zener diode ZD3 to ground GND, generating an activation signal SW.ON2 at the second node B. The voltage of the activation signal SW.ON2 is the voltage of the external power supply 30 divided across the third Zener diode ZD3. The activation signal SW.ON2 acts on the power control circuit 12 and the second detection unit 114 respectively.

[0085] The activation signal SW.ON2 acts on the gate of the first MOSFET Q2, turning on the first MOSFET Q2 and generating a low-level detection signal CHG_CHECK. This detection signal CHG_CHECK is transmitted to the controller 14. When the controller 14 is powered on, the controller 14 receives the detection signal CHG_CHECK and outputs a drive signal to the charging and discharging circuit 13, driving the charging and discharging circuit 13 to turn on, thereby connecting the external power supply 30 and the energy storage battery 20, so that the external power supply 30 charges the energy storage battery 20.

[0086] Please see Figure 6 , Figure 6 This is a circuit structure diagram of a power control circuit provided in an embodiment of the present invention, as shown below. Figure 6 As shown, the second switching unit 121 includes an eighth resistor R8, a ninth resistor R9, a tenth resistor R10, a second transistor Q3, and a fourth Zener diode ZD4. One end of the eighth resistor R8 and one end of the tenth resistor R10 are connected to the depletion activation circuit 11, specifically to GND, and are connected to the second node B. The other end of the eighth resistor R8, the anode of the fourth Zener diode ZD4, one end of the ninth resistor R9, and the emitter of the second transistor Q3 are all grounded to GND. The other end of the tenth resistor R10 is connected to the cathode of the fourth Zener diode ZD4, the other end of the ninth resistor R9, and the base of the second transistor Q3. The collector of the second transistor Q3 is electrically connected to the control terminal of the third switching unit 122 at the third node C.

[0087] The third switching unit 122 includes a twelfth resistor R12, a thirteenth resistor R13, a fourteenth resistor R14, a third transistor Q4, a fourth transistor Q5, and a second diode D2. One end of the twelfth resistor R12 is electrically connected to the second switching unit 121 at the third node C. The other end of the twelfth resistor R12 is connected to the base of the third transistor Q4 and one end of the thirteenth resistor R13. The emitter of the third transistor Q4 is connected to the base of the fourth transistor Q5. The collector of the third transistor Q4 is connected to one end of the fourteenth resistor R14. The other end of the fourteenth resistor R14 is electrically connected to the collector of the fourth transistor Q5 and the power conversion circuit 15. The emitter of the fourth transistor Q5 is connected to the other end of the thirteenth resistor R13 and the cathode of the second diode D2. The anode of the second diode D2 is connected to the positive terminal V+ of the external power supply.

[0088] When the external power supply 30 is connected to the power depletion activation circuit 11, the power depletion activation circuit 11 outputs an activation signal SW.ON2 to the second switching unit 121 through the second node B. The activation signal SW.ON2 is a high-level signal. The activation signal SW.ON2 acts on the base of the second transistor Q3, and the second transistor Q3 conducts. The voltage at the third node C is pulled down to ground GND, so the third transistor Q4 conducts. The voltage at the third node C acts on the base of the fourth transistor Q5, and the fourth transistor Q5 conducts, connecting the positive terminal V+ of the external power supply and the power supply terminal VCC of the controller. The conduction path is: positive terminal V+ of the external power supply → second diode D2 → fourth transistor Q5 → power supply terminal VCC of the controller → ground GND. The power supply terminal VCC of the controller is energized, and the controller 14 is in the power-on state.

[0089] Therefore, when the energy storage battery 20 is depleted or has a low voltage, and the external power supply 30 is connected, the depletion activation circuit 11 sends an activation signal SW.ON2 to activate the working state of the power control circuit 12, so that the power control circuit 12 is turned on and connects the external power supply 30 to the power supply terminal VCC of the controller. The power supply terminal VCC of the controller is energized, and the controller 14 is in the power-on state, which can monitor and control the recharging process of the energy storage battery 20.

[0090] Please see Figure 7 , Figure 7 This is a schematic diagram of the circuit structure of a charging and discharging circuit provided in an embodiment of this utility model, as shown below. Figure 7As shown, the charging and discharging circuit 13 includes a charging MOSFET Q6 and a discharging MOSFET Q7. The gate of the charging MOSFET Q6 is used to connect to the drive signal PWM_B. The source of the charging MOSFET Q6 is connected to the negative terminal V- of the external power supply. The drain of the charging MOSFET Q6 is connected to the drain of the discharging MOSFET Q7. The source of the MOSFET is connected to the negative terminal BAT- of the energy storage battery. The positive terminal BAT+ of the energy storage battery is connected to the positive terminal V+ of the external power supply.

[0091] After the controller 14 is powered on, it receives the detection signal CHG_CHECK output by the second detection unit 114. The detection signal CHG_CHECK is a low-level signal. When the controller 14 receives the low-level detection signal CHG_CHECK, it determines that it has been activated by the external power supply 30. Then it checks whether other parameters are abnormal. If there are no abnormalities and the charging conditions are met, it outputs the drive signal PWM_B to the charging and discharging circuit 13.

[0092] The drive signal PWM_B acts on the gate of the charging MOSFET Q6. When the charging MOSFET Q6 is turned on, the external power supply 30 charges the energy storage battery 20. The charging circuit is as follows: positive terminal V+ of the external power supply → positive terminal BAT+ of the energy storage battery → negative terminal BAT- of the energy storage battery → body diode of the discharging MOSFET Q7 → charging MOSFET Q6 → negative terminal V- of the external power supply.

[0093] Furthermore, the drive signal PWM_B is output by the controller 14, which can also monitor various parameters during the charging process, thereby enabling the monitoring and control of the charging process.

[0094] In some embodiments, when the energy storage battery is fully charged and is discharging to the load, the controller 14 sends a drive signal PWM_A to turn on the discharge MOSFET Q7 and control the charging MOSFET Q6 to turn off. Then the energy storage battery discharges to the load through the body diodes of the discharge MOSFET Q7 and the charging MOSFET Q6.

[0095] In summary, when the energy storage battery is depleted, the energy storage system replenishes the battery with an external power source. This external power source also supplies power to the controller, activating the controller, which then controls the process of replenishing the battery with the external power source. This allows for monitoring of the replenishment process and improves the safety of replenishing the energy storage battery.

[0096] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and not to limit it; under the concept of this utility model, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of different aspects of this utility model as described above, which are not provided in detail for the sake of brevity; although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model.

Claims

1. A battery management system, characterized in that, The battery management system includes: a low-power activation circuit, a power control circuit, a charging and discharging circuit, and a controller; The power depletion activation circuit is electrically connected to both the external power supply and the power control circuit. The power depletion activation circuit is used to respond to the input of the external power supply and output an activation signal to the power control circuit. The power control circuit is electrically connected to the external power supply and the power supply terminal of the controller, respectively. The power control circuit is used to respond to the input of the activation signal and connect the power supply terminal of the external power supply and the power supply terminal of the controller. The output terminal of the controller is electrically connected to the charging and discharging circuit, which is also electrically connected to the energy storage battery and the external power supply. The controller is used to output a drive signal to the charging and discharging circuit when powered on. The charging and discharging circuit is used to respond to the input of the driving signal and connect the external power supply to the energy storage battery, so as to control the external power supply to charge the energy storage battery.

2. The battery management system according to claim 1, characterized in that, The power depletion activation circuit includes a first detection unit, a first switching unit, and a voltage divider unit; The first detection unit is electrically connected to the control terminal of the first switch unit at the first node. The first detection unit is also electrically connected to the external power supply. The first detection unit is used to respond to the input of the external power supply and output a conduction signal to the first node. The first switching unit is also electrically connected to the external power supply and the voltage divider unit respectively. The first switching unit is used to respond to the input of the conduction signal and connect the electrical connection between the external power supply and the voltage divider unit. The voltage divider unit is also electrically connected to the power control circuit at the second node. The voltage divider unit is used to divide the external power supply and output the activation signal to the power control circuit through the second node.

3. The battery management system according to claim 2, characterized in that, The first detection unit includes a first resistor, a second resistor, a third resistor, and a first Zener diode; The negative terminal of the external power supply is connected to the anode of the first Zener diode and one end of the third resistor, respectively. The cathode of the first Zener diode is connected to one end of the first resistor. The other end of the first resistor, one end of the second resistor, and the control terminal of the first switching unit are connected to the first node. The other end of the second resistor is connected to the positive terminal of the external power supply.

4. The battery management system according to claim 2, characterized in that, The first switching unit includes a first diode and a first transistor; The anode of the first diode, the base of the first transistor, and the first detection unit are electrically connected to the first node. The cathode of the first diode and the emitter of the first transistor are connected to the positive terminal of the external power supply. The collector of the first transistor is electrically connected to the voltage divider unit.

5. The battery management system according to claim 2, characterized in that, The voltage divider unit includes a second Zener diode, a fourth resistor, and a third Zener diode; The cathode of the second Zener diode is electrically connected to the first switching unit, the anode of the second Zener diode is connected to one end of the fourth resistor, the other end of the fourth resistor is electrically connected to the cathode of the third Zener diode and the power control circuit at the second node, and the anode of the third Zener diode is grounded.

6. The battery management system according to claim 2, characterized in that, The power depletion activation circuit also includes a second detection unit; The second detection unit is electrically connected to the second node and the controller respectively. The second detection unit is used to respond to the input of the activation signal and output a detection signal to the controller. The controller is also configured to respond to the input of the detection signal and output the drive signal to the charging and discharging circuit.

7. The battery management system according to claim 6, characterized in that, The second detection unit includes a fifth resistor, a first MOSFET, a sixth resistor, and a seventh resistor; One end of the fifth resistor is electrically connected to the gate of the first MOS transistor and the voltage divider unit at the second node. The other end of the fifth resistor is grounded together with the source of the first MOS transistor. The drain of the first MOS transistor is electrically connected to one end of the sixth resistor and one end of the seventh resistor. The other end of the sixth resistor is connected to a DC power supply. The other end of the seventh resistor is connected to the controller.

8. The battery management system according to claim 1, characterized in that, The power control circuit includes a second switching unit and a third switching unit; The input terminal of the second switching unit is electrically connected to the power depletion activation circuit, and the output terminal of the second switching unit is electrically connected to the control terminal of the third switching unit at the third node. The second switching unit is used to respond to the input of the activation signal and output a control signal to the third switching unit. The third switching unit is also electrically connected to the external power supply and the power supply terminal of the controller, respectively. The third switching unit is used to respond to the input of the control signal and connect the external power supply and the power supply terminal of the controller.

9. The battery management system according to claim 8, characterized in that, The second switching unit includes an eighth resistor, a ninth resistor, a tenth resistor, a second transistor, and a fourth Zener diode; One end of the eighth resistor and one end of the tenth resistor are connected to the depletion activation circuit. The other end of the eighth resistor, the anode of the fourth Zener diode, one end of the ninth resistor, and the emitter of the second transistor are all grounded. The other end of the tenth resistor is connected to the cathode of the fourth Zener diode, the other end of the ninth resistor, and the base of the second transistor. The collector of the second transistor is electrically connected to the control terminal of the third switching unit at the third node.

10. The battery management system according to claim 8, characterized in that, The third switching unit includes a twelfth resistor, a thirteenth resistor, a fourteenth resistor, a third transistor, a fourth transistor, and a second diode; One end of the twelfth resistor is electrically connected to the second switching unit at the third node. The other end of the twelfth resistor is connected to the base of the third transistor and one end of the thirteenth resistor. The emitter of the third transistor is connected to the base of the fourth transistor. The collector of the third transistor is connected to one end of the fourteenth resistor. The other end of the fourteenth resistor is electrically connected to the collector of the fourth transistor and the power supply terminal of the controller. The emitter of the fourth transistor is connected to the other end of the thirteenth resistor and the cathode of the second diode. The anode of the second diode is connected to the positive terminal of the external power supply.

11. The battery management system according to any one of claims 1-10, characterized in that, The charging and discharging circuit includes a charging MOSFET and a discharging MOSFET; The gate of the charging MOSFET is used to receive the drive signal, the source of the charging MOSFET is connected to the negative terminal of the external power supply, the drain of the charging MOSFET is connected to the drain of the discharging MOSFET, the source of the MOSFET is connected to the negative terminal of the energy storage battery, and the positive terminal of the energy storage battery is connected to the positive terminal of the external power supply.

12. The battery management system according to any one of claims 1-10, characterized in that, The battery management system also includes a power conversion circuit; The input terminal of the power conversion circuit is used to connect to the external power source, and the output terminal of the power conversion circuit is electrically connected to the power supply terminal of the controller. The power conversion circuit is used to convert the external power source into the power supply for the controller.

13. An energy storage system, characterized in that, It includes an energy storage battery, an external power source, and a battery management system as described in any one of claims 1-12.

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