Integrated control circuit structure for lithium-sodium hybrid battery

Abstract

The utility model discloses a kind of integrated control circuit structure of lithium-sodium hybrid battery pack, specifically relates to battery pack control field, including lithium battery pack and sodium battery pack, the lithium battery pack is connected with lithium battery charge-discharge MOS loop, the lithium battery charge-discharge MOS loop is connected with bidirectional DCDC power module, the sodium battery pack is connected with sodium battery charge-discharge MOS loop, the sodium battery charging MOS loop connects bidirectional DCDC power module, the output end of the lithium battery pack is connected with lithium battery voltage acquisition and equalization circuit, the output end of the sodium battery pack is connected with sodium battery voltage acquisition and equalization circuit, the lithium battery voltage acquisition and equalization circuit and sodium battery voltage acquisition and equalization circuit are all connected MCU control circuit, the utility model can be according to real-time data dynamic adjustment two kinds of battery's charge-discharge current, ensure that give full play to lithium battery's high capacity and sodium battery's high voltage advantage under different working conditions, to realize the optimal allocation of energy.

Description

Technical Field

[0001] This utility model relates to the field of battery pack control circuit technology, specifically to an integrated control circuit structure for a lithium-sodium hybrid battery pack. Background Technology

[0002] With the development of energy storage technology, lithium batteries and sodium batteries are widely used due to their respective advantages: lithium batteries have high energy density and low self-discharge rate, making them suitable for applications with high energy density requirements; sodium batteries have low cost, abundant resources, and high safety, making them more promising for large-scale energy storage and high-power output scenarios. To leverage the advantages of both systems simultaneously, lithium battery modules and sodium battery modules are often connected in parallel or series to form hybrid battery packs in engineering. However, this integration of a "dual-chemical system" places higher demands on the control circuit board—it must sample, protect, and equalize the two types of cells separately, and also achieve voltage matching and energy dispatch through bidirectional DC-DC converters.

[0003] Most existing systems use a "separate board + external DC-DC converter" architecture to control the two battery packs separately. However, the shortcomings and deficiencies of this architecture are as follows: Disadvantage 1: Poor collaborative control capability. The lithium battery management board and the sodium battery management board are independent of each other, lacking a high-speed communication interface, and cannot share SOC, SOH, temperature, and internal resistance information in real time. During charging and discharging, the system cannot dynamically allocate current according to the real-time status and load demand of the two types of cells, resulting in one cell being over-discharged while the other cell still has a large amount of remaining capacity, leading to low overall energy utilization. Disadvantage 2: Lack of DC-DC control function. Traditional architectures place the DC-DC power module independently outside the battery pack, requiring control signals to be transmitted over long distances via wiring harnesses, resulting in significant delays and poor interference resistance. Furthermore, the lack of unified scheduling between the DC-DC unit and the BMS makes it difficult to accurately boost the lower voltage of the lithium battery pack to the higher voltage required by the sodium battery pack and load during discharge, and also makes it impossible to efficiently step down the external high voltage to the lithium battery pack during charging, leading to energy waste and even the risk of overcharging. Disadvantage 3: Low system integration. Independent lithium battery management boards, sodium battery management boards, and external DC-DC modules occupy a lot of space. The crisscrossing wiring harnesses and numerous connectors not only increase the size and weight but also reduce system reliability. This defect is particularly prominent in space-constrained scenarios such as new energy vehicles and energy storage containers, and troubleshooting and maintenance are difficult. Summary of the Invention

[0004] The purpose of this invention is to provide an integrated control circuit structure for a lithium-sodium hybrid battery pack to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, this utility model provides the following technical solution: An integrated control circuit structure for a lithium-sodium hybrid battery pack includes a lithium battery pack and a sodium battery pack. The lithium battery pack is connected to a lithium battery charging and discharging MOS circuit, which is connected to a bidirectional DC-DC power module. The sodium battery pack is connected to a sodium battery charging and discharging MOS circuit, which is also connected to the bidirectional DC-DC power module. The output terminal of the lithium battery pack is connected to a lithium battery voltage acquisition and equalization circuit, and the output terminal of the sodium battery pack is connected to a sodium battery voltage acquisition and equalization circuit. Both the lithium battery voltage acquisition and equalization circuit and the sodium battery voltage acquisition and equalization circuit are connected to an MCU control circuit.

[0006] In a preferred embodiment, the lithium battery pack is a low-number-per-cell, high-capacity battery pack, and the sodium battery pack is a high-number-per-cell, low-capacity battery pack. The lithium battery pack is designed with a low number of cells and a high capacity, while the sodium battery pack is designed with a high number of cells and a low capacity. The two are connected by a bidirectional DC-DC power module.

[0007] In a preferred embodiment, the lithium battery charge / discharge MOS circuit includes a sampling resistor connected to the negative terminal of the lithium battery pack. The sampling resistor is connected to an over-discharge control circuit and an over-charge control circuit. The over-charge control circuit is connected to the negative terminal of the charger, and a charger detection circuit is provided between the over-charge control circuit and the negative terminal of the charger. The main function of the lithium battery charge / discharge MOS circuit is to control and protect the lithium battery charge / discharge. Components such as the three-terminal fuse and the sampling resistor can effectively ensure charge / discharge safety and realize current monitoring. The over-discharge and over-charge control circuit can reliably prevent the battery from being overcharged or over-discharged.

[0008] In a preferred embodiment, the lithium battery charging and discharging MOS circuit further includes a three-terminal fuse connected to the positive terminal of the lithium battery pack, and the three-terminal fuse is connected to the fuse blowout control circuit through a short-circuit cap.

[0009] In a preferred embodiment, the sodium battery charge / discharge MOS circuit includes a sampling resistor connected to the negative terminal of the sodium battery pack. The sampling resistor is connected to an over-discharge control circuit and an over-charge control circuit. The over-charge control circuit is connected to a charger detection circuit, which is connected to a fuse control circuit. The over-charge, over-discharge control, and load / charger detection circuits can ensure the safe and stable charging and discharging of the sodium battery.

[0010] In a preferred embodiment, the bidirectional DC-DC power module includes a Boost circuit and a Buck circuit. The Boost circuit increases the low-voltage side voltage, and the Buck circuit decreases the high-voltage side voltage. The DC-DC power module acts as a system energy regulator, intelligently switching between charging and discharging modes. During discharging (when the system supplies power externally), it operates in Boost mode, increasing the low-voltage side (lithium battery / sodium battery side) voltage to meet load demands. During charging (when external energy is supplied to the system), it switches to Buck mode, decreasing the high-voltage side (external input) voltage to replenish energy to the battery pack.

[0011] In a preferred embodiment, both the lithium battery voltage acquisition and equalization circuit and the sodium battery voltage acquisition and equalization circuit include terminals connected to the lithium battery pack and the sodium battery pack, respectively. These terminals are connected to an AFE chip, which analyzes and processes the data before transmitting it to the MCU control circuit. The lithium battery voltage acquisition and equalization circuit and the sodium battery voltage acquisition and equalization circuit are used to acquire parameters such as voltage and temperature of the lithium battery and sodium battery, and to perform battery equalization management. The AFE chip, in conjunction with numerous resistors and capacitors, accurately completes data acquisition, and the differential wiring design improves acquisition accuracy, effectively ensuring battery pack consistency.

[0012] Compared with the prior art, the beneficial effects of this utility model are as follows: This utility model adopts an integrated battery management system, which monitors and manages the status of lithium battery pack and sodium battery pack simultaneously through an integrated PCB board. It can dynamically adjust the charging and discharging current of the two types of batteries according to real-time data, ensuring that the high capacity of lithium battery and the high voltage of sodium battery are fully utilized under different working conditions, thereby achieving optimal energy allocation and significantly improving the energy utilization efficiency of the system. This invention utilizes an integrated battery management system to precisely control a bidirectional DC-DC power module. During discharge, it efficiently boosts the voltage, converting the low voltage of the lithium battery pack to a high voltage suitable for the load; during charging, it precisely reduces the voltage, providing the appropriate charging voltage for the lithium battery pack. This efficient energy conversion mechanism significantly reduces energy loss, improves the overall system efficiency, and extends the battery pack's lifespan. This invention integrates the management functions of lithium battery pack, sodium battery pack, and DC-DC module onto a single PCB board, achieving a truly integrated design. This highly integrated solution not only reduces the physical size and weight of the system but also lowers system complexity and improves system reliability and maintainability. It is particularly suitable for space-constrained applications, such as new energy vehicles and distributed energy storage systems. This utility model's integrated battery management system, through precise control algorithms and flexible energy management strategies, can dynamically adjust the working state of lithium battery packs and sodium battery packs according to the needs of different application scenarios. Whether in devices requiring high energy output or systems requiring high voltage support, it can achieve complementary advantages of the two types of batteries, and has wide applicability and flexibility. Attached Figure Description

[0013] The accompanying drawings are provided to further illustrate the present invention and form part of the specification. They are used together with the embodiments of the present invention to explain the present invention, but do not constitute a limitation thereof. In the drawings: Figure 1 This is a schematic diagram of the overall structure of this utility model; Figure 2 This is a schematic diagram of the lithium battery charging and discharging MOS circuit structure of this utility model; Figure 3 This is a schematic diagram of the sodium battery charging and discharging MOS circuit structure of this utility model; Figure 4 This is a schematic diagram of the Boost converter circuit structure in the bidirectional DC-DC power module of this utility model; Figure 5 This is a schematic diagram of the Buck step-down circuit structure in the bidirectional DC-DC power module of this utility model; Figure 6 This is a schematic diagram of the lithium battery voltage acquisition and equalization circuit structure of this utility model; Figure 7 This is a schematic diagram of the sodium battery voltage acquisition and equalization circuit structure of this utility model; Figure 8 This is a schematic diagram of the MCU control circuit structure of this utility model.

[0014] In the diagram: 1. Lithium battery pack; 2. Sodium battery pack; 3. Lithium battery charging and discharging MOS circuit; 4. Bidirectional DC-DC power module; 5. Sodium battery charging and discharging MOS circuit; 6. Lithium battery voltage acquisition and equalization circuit; 7. Sodium battery voltage acquisition and equalization circuit; 8. MCU control circuit. Detailed Implementation

[0015] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0016] Please see Figures 1-8This utility model provides an integrated control circuit structure for a lithium-sodium hybrid battery pack, the technical solution of which is as follows: An integrated control circuit structure for a lithium-sodium hybrid battery pack includes a lithium battery pack 1 and a sodium battery pack 2. The lithium battery pack 1 is connected to a lithium battery charging and discharging MOS circuit 3, which is connected to a bidirectional DC-DC power module 4. The sodium battery pack 2 is connected to a sodium battery charging and discharging MOS circuit 5, which is connected to the bidirectional DC-DC power module 4. The output terminal of the lithium battery pack 1 is connected to a lithium battery voltage acquisition and equalization circuit 6, and the output terminal of the sodium battery pack 2 is connected to a sodium battery voltage acquisition and equalization circuit 7. Both the lithium battery voltage acquisition and equalization circuit 6 and the sodium battery voltage acquisition and equalization circuit 7 are connected to an MCU control circuit 8.

[0017] In a preferred embodiment, the lithium battery pack 1 is a low-cell-count, high-capacity battery pack, and the sodium battery pack 2 is a high-cell-count, low-capacity battery pack.

[0018] In a preferred embodiment, the lithium battery charging and discharging MOS circuit 3 includes a sampling resistor connected to the negative terminal of the lithium battery pack 1. The sampling resistor is connected to an over-discharge control circuit and an over-charge control circuit. The over-charge control circuit is connected to the negative terminal of the charger, and a charger detection circuit is provided between the over-charge control circuit and the negative terminal of the charger.

[0019] In a preferred embodiment, the lithium battery charging and discharging MOS circuit 3 further includes a three-terminal fuse connected to the positive terminal of the lithium battery pack 1, and the three-terminal fuse is connected to the fuse blowout control circuit through a short-circuit cap.

[0020] In a preferred embodiment, the sodium battery charge / discharge MOS circuit 5 includes a sampling resistor connected to the negative terminal of the sodium battery pack 2. The sampling resistor is connected to an over-discharge control circuit and an over-charge control circuit. The over-charge control circuit is connected to a charger detection circuit, and the charger detection circuit is connected to a fuse control circuit.

[0021] In a preferred embodiment, the bidirectional DC-DC power module 4 includes a Boost circuit and a Buck circuit, wherein the Boost circuit is used to increase the low-voltage side voltage and the Buck circuit is used to decrease the high-voltage side voltage.

[0022] In a preferred embodiment, both the lithium battery voltage acquisition and equalization circuit 6 and the sodium battery voltage acquisition and equalization circuit 7 include terminals connected to the lithium battery pack 1 and the sodium battery pack 2. The terminals are connected to an AFE chip, which analyzes and processes the data and transmits it to the MCU control circuit 8.

[0023] The working principle of this utility model is as follows: Discharge process When the system discharges, the bidirectional DC-DC power module 4 operates in the modulation Boost circuit, and the electrical energy stored in the lithium battery pack 1 is released through the lithium battery charging and discharging MOS circuit 3. At this time, the lithium battery current sampling resistor will detect the current, and the lithium battery voltage acquisition and equalization circuit 6 will monitor the voltage of the lithium battery pack in real time and transmit the data to the MCU control circuit 8. The MCU control circuit 8 sends control signals to the Boost converter circuit based on the voltage and current of the lithium battery pack 1 and the preset control strategy. By adjusting the relevant control signals (BOOST_CTL), the relatively low voltage output by the lithium battery pack 1 is boosted to a higher voltage suitable for the sodium battery pack and the load, providing a stable power output for the external load.

[0024] During this process, the system also monitors parameters such as the voltage of the sodium battery pack 2 to ensure a stable and safe discharge process. Simultaneously, relevant data from the sodium battery pack 2 is collected by the sodium battery voltage acquisition and equalization circuit 7 and fed back to the MCU control circuit 8, allowing the MCU control circuit 8 to comprehensively consider the states of both batteries and perform coordinated control. Charging process When charging the system, the bidirectional DC-DC power module 4 operates in the Buck step-down circuit. The power from the external power supply first enters the sodium battery pack 2. The voltage of the sodium battery pack 2 is collected by the sodium battery voltage acquisition and equalization circuit 7 and then fed back to the MCU control circuit 8. The MCU control circuit 8 sends control signals to the Buck step-down converter circuit according to the state of the sodium battery pack and the charging requirements of the lithium battery pack. By adjusting the relevant control signals (BUCK_CTL), the higher voltage of the external power supply is stepped down to a lower voltage suitable for charging the lithium battery pack, and the lithium battery pack 1 is charged through the lithium battery charging and discharging MOS circuit 3. This ensures that the lithium battery pack 1 receives the appropriate charging voltage, avoiding undercharging or overcharging, while also improving charging efficiency and reducing energy loss during the conversion process. The system monitors the voltage, current, and temperature of lithium battery pack 1 and sodium battery pack 2 in real time. Lithium battery pack 1 and sodium battery pack 2 transmit temperature information to the MCU control circuit 8 through their respective temperature acquisition circuits (NTC1, NTC2, etc.). The MCU control circuit 8 performs over-temperature protection control on the battery packs based on preset temperature protection thresholds. For example, when the battery pack temperature is too high or too low, the MCU control circuit 8 can take corresponding measures, such as adjusting the charging or discharging power, or even suspending the charging and discharging operation, to protect the safety of the battery packs.

[0025] The system also features overcharge and over-discharge control for lithium-ion batteries and sodium-ion batteries. Through corresponding control circuits, such as the overcharge and over-discharge control circuits for lithium-ion batteries and sodium-ion batteries, the charging and discharging process of the battery pack is strictly managed to ensure that the battery pack operates within a safe voltage range and extend its service life.

[0026] The integrated PCB board enables coordinated control and management of both lithium-ion and sodium-ion battery packs. The lithium-ion battery pack employs a low-cell-count, high-capacity design, while the sodium-ion battery pack features a high-cell-count, low-capacity design. They are connected via a bidirectional DC-DC converter module. During discharge, the DC-DC converter operates in boost mode, converting the low voltage of the lithium-ion battery pack to a high voltage suitable for the sodium-ion battery pack and the load. During charging, the DC-DC converter operates in buck mode, converting the high voltage from the external power supply to the low voltage required by the lithium-ion battery pack. The integrated battery management system monitors the voltage, current, and temperature of both battery packs in real time and dynamically adjusts the operating state of the DC-DC converter module based on these parameters. This optimizes the charging and discharging process of the lithium-ion and sodium-ion battery packs, achieving efficient energy distribution and conversion, thereby improving the overall performance and efficiency of the hybrid battery pack.

[0027] Finally, it should be noted that the above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. An integrated control circuit structure for a lithium-sodium hybrid battery pack, comprising a lithium battery pack (1) and a sodium battery pack (2), characterized in that: The lithium battery pack (1) is connected to a lithium battery charging and discharging MOS circuit (3), the lithium battery charging and discharging MOS circuit (3) is connected to a bidirectional DC-DC power module (4), the sodium battery pack (2) is connected to a sodium battery charging and discharging MOS circuit (5), the sodium battery charging and discharging MOS circuit (5) is connected to a bidirectional DC-DC power module (4), the output terminal of the lithium battery pack (1) is connected to a lithium battery voltage acquisition and equalization circuit (6), the output terminal of the sodium battery pack (2) is connected to a sodium battery voltage acquisition and equalization circuit (7), and both the lithium battery voltage acquisition and equalization circuit (6) and the sodium battery voltage acquisition and equalization circuit (7) are connected to an MCU control circuit (8).

2. The integrated control circuit structure of a lithium-sodium hybrid battery pack according to claim 1, characterized in that: The lithium battery pack (1) is a low-number-of-strings, high-capacity battery pack, and the sodium battery pack (2) is a high-number-of-strings, low-capacity battery pack.

3. The integrated control circuit structure of a lithium-sodium hybrid battery pack according to claim 1, characterized in that: The lithium battery charging and discharging MOS circuit (3) includes a sampling resistor connected to the negative terminal of the lithium battery pack (1). The sampling resistor is connected to an over-discharge control circuit and an over-charge control circuit. The over-charge control circuit is connected to the negative terminal of the charger, and a charger detection circuit is provided between the over-charge control circuit and the negative terminal of the charger.

4. The integrated control circuit structure of a lithium-sodium hybrid battery pack according to claim 3, characterized in that: The lithium battery charging and discharging MOS circuit (3) also includes a three-terminal fuse connected to the positive terminal of the lithium battery pack (1), and the three-terminal fuse is connected to the fuse blowout control circuit through a short-circuit cap.

5. The integrated control circuit structure of a lithium-sodium hybrid battery pack according to claim 1, characterized in that: The sodium battery charge / discharge MOS circuit (5) includes a sampling resistor connected to the negative terminal of the sodium battery pack (2). The sampling resistor is connected to an over-discharge control circuit and an over-charge control circuit. The over-charge control circuit is connected to a charger detection circuit, and the charger detection circuit is connected to a fuse control circuit.

6. The integrated control circuit structure of a lithium-sodium hybrid battery pack according to claim 1, characterized in that: The bidirectional DC-DC power module (4) includes a Boost circuit and a Buck circuit. The Boost circuit is used to increase the voltage on the low-voltage side, and the Buck circuit is used to decrease the voltage on the high-voltage side.

7. The integrated control circuit structure of a lithium-sodium hybrid battery pack according to claim 1, characterized in that: The lithium battery voltage acquisition and equalization circuit (6) and the sodium battery voltage acquisition and equalization circuit (7) both include terminals connected to the lithium battery pack (1) and the sodium battery pack (2). The terminals are connected to an AFE chip, which analyzes and processes the data and transmits it to the MCU control circuit (8).

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