Low-power-consumption BMS (Battery Management System)
By combining the MCU detection circuit status in the BMS system and controlling the enable signals of the DC buck module and the linear buck module, the power consumption and heat generation issues of the BMS system under different operating conditions are solved, achieving power supply optimization with low power consumption and low heat generation.
Patent Information
- Application Number
- CN202423005168.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-04
- Publication Date
- 2025-12-09
- Estimated Expiration
- 2034-12-04
AI Technical Summary
Existing BMS systems suffer from high power consumption during sleep or high power consumption and heat generation during normal operation, especially when using DC-DC buck conversion, which results in high power consumption during sleep, and when using linear buck LDO conversion, which results in high power consumption and heat generation during normal operation.
An MCU is used to detect the circuit status and control the enable signals of the DC-DC buck module and the linear buck module. Different voltages are output during normal operation and sleep mode, respectively. By using the DC-DC buck module and the linear buck module in combination, electrical isolation is achieved, reducing system power consumption and avoiding the heat problems caused by using the linear buck module alone.
It achieves optimized power supply under different operating conditions, reduces the overall power consumption of the BMS system, avoids the problem of excessive circuit heat, simplifies the circuit structure, and reduces costs.
Smart Images
Figure CN223651985U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of battery management system (BMS) power technology, and in particular to a low-power BMS. Background Technology
[0002] As a key component of battery energy storage systems, the Battery Management System (BMS) can draw power from the battery pack or from an external power source, such as AC mains power. For off-grid and semi-off-grid applications, the instability of the external power supply cannot guarantee the normal operation of the BMS. Therefore, the BMS typically draws power from the battery pack to meet its independent operation requirements.
[0003] The battery pack itself has limited energy. For the BMS to draw power from the battery pack, it must meet the requirements of low power consumption during normal operation, as well as sleep and wake-up functions. This ensures that the battery pack is not over-discharged and that it can be smoothly woken up from sleep mode and recharged.
[0004] BMS systems need to minimize operating power consumption. Currently, the most common power supply methods for BMS systems are DC-DC or linear low-voltage LDO power supplies. However, using DC-DC step-down alone results in high power consumption after the system goes into sleep mode, while using linear step-down LDO alone results in high power consumption and high heat generation during normal operation. Utility Model Content
[0005] Existing battery management systems, when using DC-DC buck conversion, have high power consumption after the system goes to sleep, while when using linear buck LDO conversion, they have high power consumption and high heat generation during normal operation.
[0006] To address the aforementioned issues, a low-power BMS is proposed. The MCU detects the circuit's operating status and enables the DC-DC buck module during normal operation, outputting a first voltage for the MCU and control circuit. During sleep mode, the MCU enables the linear buck module to output a second voltage for the MCU and control circuit. This reduces the BMS's power consumption and avoids the problem of high circuit heat caused by using the linear buck module alone.
[0007] A low-power BMS, comprising:
[0008] MCU;
[0009] DC step-down module;
[0010] Linear buck module;
[0011] Isolation module;
[0012] The DC-DC step-down module and the linear step-down module are respectively electrically connected to the MCU;
[0013] The DC-DC step-down module is used to convert the lithium battery output voltage into a first voltage according to the MCU instructions, for use by the MCU or control circuit during normal operation.
[0014] The linear buck module is used to convert the lithium battery output voltage into a second voltage according to the MCU instructions, for use by the MCU or control circuit during sleep mode.
[0015] The isolation modules are respectively connected between the DC buck module and the MCU, and between the linear buck module and the MCU, for electrical isolation.
[0016] In conjunction with the low-power BMS described in this utility model, in a first possible implementation, the MCU includes a circuit status detection unit;
[0017] The circuit status detection unit is used to detect the normal operation or sleep operation status of the circuit, and transmits enable signals to the DC buck module and the linear buck module respectively.
[0018] In conjunction with the first possible embodiment of this utility model, in the second possible embodiment, the isolation module includes:
[0019] First diode and second diode;
[0020] The anode and cathode of the first diode are respectively connected to the output terminal of the DC-DC step-down module and the MCU;
[0021] The anode and cathode of the second diode are respectively connected to the output terminal of the linear buck module and the MCU.
[0022] In conjunction with the second possible embodiment of this utility model, and in the third possible embodiment, the DC-DC step-down module includes:
[0023] The system comprises a first filtering unit, a first switch control unit, a first processing chip, an output unit, and a second filtering unit.
[0024] The first filtering unit and the first switch control unit are respectively connected to the input pin and the enable pin of the first processing chip, the output pin of the first processing chip is connected to the output unit, and the output unit is electrically connected to the second filtering unit.
[0025] In conjunction with the second possible embodiment of this utility model, and the fourth possible embodiment, the linear buck module includes:
[0026] Voltage regulator unit, third filter unit, second switch control unit, second processing chip, fourth filter unit;
[0027] The voltage regulator unit, the third filter unit, and the second switch control unit are electrically connected in sequence. The second switch control unit is connected to the second processing chip, and the output pin of the second processing chip is connected to the fourth filter unit.
[0028] In conjunction with the third possible implementation of this utility model, and in the fifth possible implementation, the first filtering unit includes:
[0029] First capacitor and second capacitor;
[0030] The first terminal of the first capacitor and the second capacitor are connected to the input pins of the battery pack and the first processing chip, and the second terminals of the first capacitor and the second capacitor are connected together and grounded.
[0031] In conjunction with the fifth possible embodiment of this utility model, and in the sixth possible embodiment, the first switch control unit includes:
[0032] First switching transistor, third diode, first resistor;
[0033] The first input terminal and the second input terminal of the first switch are electrically connected to the first enable terminal and the second enable terminal of the MCU, respectively. The anode of the third diode is electrically connected to the second input terminal and the second input terminal of the first switch, and the cathode of the third diode is electrically connected to the first terminal of the first resistor.
[0034] In conjunction with the sixth and seventh possible embodiments of this utility model, the output unit includes:
[0035] The third capacitor and the first inductor;
[0036] The first end of the third capacitor is electrically connected to the output pin of the first processing chip, the second end is electrically connected to the first end of the first inductor, and the second end of the first inductor is electrically connected to the second filter unit.
[0037] In conjunction with the fourth possible embodiment of this utility model, and in the eighth possible embodiment, the voltage stabilizing unit includes:
[0038] Fourth diode, second resistor and fifth diode;
[0039] The fourth diode and the second resistor are connected in sequence, and the cathode of the fifth diode is connected to the second resistor, the third filter unit and the second switch control unit respectively.
[0040] The anode of the fifth diode is grounded.
[0041] In conjunction with the eighth and ninth possible embodiments of this utility model, the second switch control unit includes:
[0042] Second switch, third resistor, fourth resistor;
[0043] The drain of the second switch is electrically connected to the second resistor, the third filter unit, and the cathode of the fifth diode. The source is connected to the first end of the third resistor and the input pin of the second processing chip. The second end of the third resistor is grounded. The gate is connected to the first end of the fourth resistor, and the second end of the fourth resistor is grounded.
[0044] The low-power BMS described in this utility model uses an MCU to detect the circuit's operating status. During normal operation, it enables and controls the DC buck module to operate, outputting a first voltage for the MCU and control circuit. During sleep mode, it enables and controls the linear buck module to output a second voltage for the MCU and control circuit. This reduces the power consumption of the BMS and avoids the problem of high circuit heat caused by using the linear buck module alone. Attached Figure Description
[0045] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0046] Figure 1 This is a module structure diagram of a low-power BMS according to the present invention;
[0047] Figure 2 This is a schematic diagram of the module circuit structure of the low-power BMS in this utility model;
[0048] Figure 3 This is a diagram showing the electronic component connection structure of the low-power BMS in this invention;
[0049] Components and their serial numbers:
[0050] 100 – DC step-down module, 200 – linear step-down module, 300 – isolation module, 400 – MCU. Detailed Implementation
[0051] The technical solutions of this utility model will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this utility model, and not all of them. Based on the embodiments of this utility model, other embodiments obtained by those skilled in the art without creative effort are all within the scope of protection of this utility model.
[0052] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.
[0053] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.
[0054] It should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.
[0055] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.
[0056] Existing battery management systems, when using DC-DC buck conversion, have high power consumption after the system goes to sleep, while when using linear buck LDO conversion, they have high power consumption and high heat generation during normal operation.
[0057] To address the above issues, a low-power BMS is proposed.
[0058] A low-power BMS, such as Figure 1 , Figure 1This is a module structure diagram of a low-power BMS according to the present invention; it includes an MCU400, a DC-DC buck module 100, a linear buck module 200, and an isolation module 300; the DC-DC buck module 100 and the linear buck module 200 are electrically connected to the MCU400 respectively; the DC-DC buck module 100 is used to convert the lithium battery output voltage into a first voltage according to the instructions of the MCU400, for use by the MCU400 or control circuit during normal operation; the linear buck module 200 is used to convert the lithium battery output voltage into a second voltage according to the instructions of the MCU400, for use by the MCU400 or control circuit during sleep mode; the isolation module 300 is connected between the DC-DC buck module 100 and the MCU400, and between the linear buck module 200 and the MCU400 respectively, for electrical isolation. The MCU400 detects the circuit's operating status. During normal operation, it enables the DC buck module 100 to operate and outputs a first voltage for use by the MCU400 and control circuit. During sleep mode, it enables the linear buck module 200 to output a second voltage for use by the MCU400 and control circuit. This reduces the power consumption of the BMS and avoids the problem of high circuit heat caused by using the linear buck module 200 alone.
[0059] In a preferred embodiment, the MCU400 includes a circuit status detection unit; the circuit status detection unit is used to detect the normal operation or sleep operation state of the circuit, and transmits enable signals to the DC buck module 100 and the linear buck module 200 respectively.
[0060] In a preferred embodiment, such as Figure 2 , Figure 2 This is a circuit diagram of the low-power BMS module in this utility model; the isolation module 300 includes a first diode D1 and a second diode D2; the anode and cathode of the first diode D1 are respectively connected to the output terminal of the DC buck module 100 and the MCU400; the anode and cathode of the second diode D2 are respectively connected to the output terminal of the linear buck module 200 and the MCU400.
[0061] In this embodiment, the DC-DC step-down module 100 is a DC-DC circuit, and the linear step-down module 200 is an LDO circuit, such as... Figure 2The MCU400 power supply has two inputs: one is a 3.7V DC-DC output, and the other is a 3.3V linear low-power LDO output. The two power supplies are isolated by diodes to prevent them from interfering with each other. When the BMS system is working normally, the DC-DC circuit is enabled. Since the output voltage of the DC-DC circuit is higher than that of the linear LDO, the DC-DC output power is used at this time. When the BMS system needs to enter low-power mode, the DC-DC circuit is disabled, and the MCU400 power supply is provided by the linear LDO, thus enabling the BMS to enter the lowest power mode.
[0062] In this embodiment, the BMS is powered by two power supplies: one is a DC-DC converter and the other is a linear LDO. The two power supplies are isolated by diodes. During normal operation, the BMS uses the DC-DC output power supply, and when entering low-power mode, it uses the linear LDO output power supply.
[0063] The most common power supply system for lithium battery management uses a DC-DC converter, which can lead to high power consumption during sleep. In this embodiment, a linear low-power LDO is used after entering the lowest power consumption state to avoid the problem of high power consumption during sleep.
[0064] Another power supply system for lithium battery management uses a linear low-power LDO, which leads to high power consumption during normal operation. In this embodiment, a DC-DC method is used during normal operation, which can avoid the problem of high power consumption during normal operation.
[0065] Some lithium battery management power supply systems use a dual-path DC-DC + LDO power supply, but the circuit is complex and the cost is high. In this embodiment, the architecture is simpler and the cost is reduced. Finally, diode isolation is used to output to the BMS power supply system.
[0066] This application combines the advantages of both DC-DC power supplies and linear low-power LDO power supplies. When operating at high current, a DC-DC power supply is used to reduce power consumption, while a linear low-power LDO power supply is used when entering the lowest power consumption mode, thereby enabling the entire BMS system to operate in the lowest power consumption mode.
[0067] Furthermore, the DC-DC step-down module 100 includes: a first filter unit, a first switch control unit, a first processing chip U1, an output unit, and a second filter unit; the first filter unit and the first switch control unit are respectively connected to the input pin and the enable pin of the first processing chip U1, the output pin of the first processing chip U1 is connected to the output unit, and the output unit is electrically connected to the second filter unit.
[0068] Furthermore, the linear buck module 200 includes a voltage regulator unit, a third filter unit, a second switch control unit, a second processing chip U2, and a fourth filter unit; the voltage regulator unit, the third filter unit, and the second switch control unit are electrically connected in sequence, the second switch control unit is connected to the second processing chip U2, and the output pin of the second processing chip U2 is connected to the fourth filter unit.
[0069] Specifically, such as Figure 3 , Figure 3 This is a diagram showing the electronic component connection structure of the low-power BMS in this utility model; the first filter unit includes a first capacitor C1 and a second capacitor C2; the first ends of the first capacitor C1 and the second capacitor C2 are connected to the input pins of the battery pack and the first processing chip U1, and the second ends of the first capacitor C1 and the second capacitor C2 are connected to ground.
[0070] Specifically, such as Figure 3 The first switch control unit includes a first switch transistor Z5, a third diode D3, and a first resistor R1. The first input terminal and the second input terminal of the first switch transistor Z5 are electrically connected to the first enable terminal (POWER_EN) and the second enable terminal (BMS_EN) of the MCU400, respectively. The anode of the third diode D3 is electrically connected to the second input terminal and the second input terminal of the first switch transistor Z5, and the cathode of the third diode D3 is electrically connected to the first terminal of the first resistor R1.
[0071] Specifically, such as Figure 3 The output unit includes a third capacitor C3 and a first inductor L1; the first end of the third capacitor C3 is electrically connected to the output pin of the first processing chip U1, the second end is electrically connected to the first end of the first inductor L1, and the second end of the first inductor L1 is electrically connected to the second filter unit.
[0072] In addition, such as Figure 3 The second filter unit includes R6, R7, C4, and C5.
[0073] Specifically, such as Figure 3 The voltage regulator unit includes a fourth diode D4, a second resistor R2, and a fifth diode D5; the fourth diode D4 and the second resistor R2 are electrically connected in sequence, and the cathode of the fifth diode D5 is electrically connected to the second resistor R2, the third filter unit, and the second switch control unit respectively; the anode of the fifth diode D5 is grounded.
[0074] Specifically, such as Figure 3The second switch control unit includes a second switch transistor Q1, a third resistor R3, and a fourth resistor R4. The drain of the second switch transistor Q1 is electrically connected to the second resistor R2, the third filter unit, and the cathode of the fifth diode D5. The source is connected to the first end of the third resistor R3 and the input pin of the second processing chip U2. The second end of the third resistor R3 is grounded. The gate is connected to the first end of the fourth resistor R4. The second end of the fourth resistor R4 is grounded.
[0075] In addition, the third filtering unit includes C6. The fourth filtering unit includes C7, C8, and C9.
[0076] The low-power BMS of this invention uses MCU400 to detect the circuit's operating status. During normal operation, it enables and controls the DC buck module 100 to operate, outputting a first voltage for use by MCU400 and the control circuit. During sleep mode, it enables and controls the linear buck module 200 to output a second voltage for use by MCU400 and the control circuit. This reduces the power consumption of the BMS and avoids the problem of high circuit heat caused by using the linear buck module 200 alone.
[0077] The above are merely preferred embodiments of the present utility model and are not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model shall be included within the protection scope of the present utility model.
Claims
1. A low-power BMS, characterized in that it comprises: MCU; DC step-down module; Linear buck module; Isolation module; The DC-DC step-down module and the linear step-down module are respectively electrically connected to the MCU; The DC-DC step-down module is used to convert the lithium battery output voltage into a first voltage according to the MCU instructions, for use by the MCU or control circuit during normal operation. The linear buck module is used to convert the lithium battery output voltage into a second voltage according to the MCU instructions, for use by the MCU or control circuit during sleep mode. The isolation modules are respectively connected between the DC buck module and the MCU, and between the linear buck module and the MCU, for electrical isolation.
2. The low-power BMS according to claim 1, characterized in that, The MCU includes a circuit status detection unit; The circuit status detection unit is used to detect the normal operation or sleep operation status of the circuit, and transmits enable signals to the DC buck module and the linear buck module respectively.
3. The low-power BMS according to claim 2, characterized in that, The isolation module includes: First diode and second diode; The anode and cathode of the first diode are respectively connected to the output terminal of the DC-DC step-down module and the MCU; The anode and cathode of the second diode are respectively connected to the output terminal of the linear buck module and the MCU.
4. The low-power BMS according to claim 3, characterized in that, The DC-DC step-down module includes: The system comprises a first filtering unit, a first switch control unit, a first processing chip, an output unit, and a second filtering unit. The first filtering unit and the first switch control unit are respectively connected to the input pin and the enable pin of the first processing chip, the output pin of the first processing chip is connected to the output unit, and the output unit is electrically connected to the second filtering unit.
5. The low-power BMS according to claim 3, characterized in that, The linear buck module includes: Voltage regulator unit, third filter unit, second switch control unit, second processing chip, fourth filter unit; The voltage regulator unit, the third filter unit, and the second switch control unit are electrically connected in sequence. The second switch control unit is connected to the second processing chip, and the output pin of the second processing chip is connected to the fourth filter unit.
6. The low-power BMS according to claim 4, characterized in that, The first filtering unit includes: First capacitor and second capacitor; The first terminal of the first capacitor and the second capacitor are connected to the input pins of the battery pack and the first processing chip, and the second terminals of the first capacitor and the second capacitor are connected together and grounded.
7. The low-power BMS according to claim 6, characterized in that, The first switch control unit includes: First switching transistor, third diode, first resistor; The first input terminal and the second input terminal of the first switch are electrically connected to the first enable terminal and the second enable terminal of the MCU, respectively. The anode of the third diode is electrically connected to the second input terminal and the second input terminal of the first switch, and the cathode of the third diode is electrically connected to the first terminal of the first resistor.
8. The low-power BMS according to claim 7, characterized in that, The output unit includes: The third capacitor and the first inductor; The first end of the third capacitor is electrically connected to the output pin of the first processing chip, the second end is electrically connected to the first end of the first inductor, and the second end of the first inductor is electrically connected to the second filter unit.
9. The low-power BMS according to claim 5, characterized in that, The voltage stabilizing unit includes: Fourth diode, second resistor and fifth diode; The fourth diode and the second resistor are connected in sequence, and the cathode of the fifth diode is connected to the second resistor, the third filter unit and the second switch control unit respectively. The anode of the fifth diode is grounded.
10. The low-power BMS according to claim 9, characterized in that, The second switch control unit includes: Second switch, third resistor, fourth resistor; The drain of the second switch is electrically connected to the second resistor, the third filter unit, and the cathode of the fifth diode. The source is connected to the first end of the third resistor and the input pin of the second processing chip. The second end of the third resistor is grounded. The gate is connected to the first end of the fourth resistor, and the second end of the fourth resistor is grounded.