Intelligent equalization management system for multiple groups of parallel lithium batteries and control method

Abstract

The invention relates to the technical field of lithium batteries, in particular to an intelligent balance management system and control method for multiple groups of lithium batteries connected in parallel, and the system comprises a plurality of battery packs connected in parallel, a BMS and a current distribution module; the BMS comprises a multi-channel monitoring unit used for collecting voltage, temperature and current parameters of each group of batteries in real time; the dynamic balance control unit is used for adjusting loads among the battery packs based on the monitoring data, so that the voltage and the capacity of each group of batteries are kept consistent; the protection execution unit is used for cutting off the circuit when the voltage is abnormal or the temperature exceeds the limit; the current distribution module distributes the output current of each group of batteries in a balanced manner according to a BMS instruction, the intelligent balanced management system and the control method of the multi-group parallel lithium batteries support the parallel connection of any groups of batteries, and the endurance mileage is increased as required; the multi-group parallel risk is solved through dynamic balancing and fusing protection; a plurality of groups of batteries can share load power.

Description

Technical Field

[0001] The present invention relates to the technical field of lithium batteries, and in particular to an intelligent balancing management system and a control method for multiple groups of parallel lithium batteries. Background Art

[0002] With the gradual development of the electric motorcycle market, the performance of batteries, as core components of electric motorcycles, directly affects the endurance, power output, and safety of electric motorcycles. Currently, most electric motorcycles on the market use a single battery pack, which has problems such as limited capacity and power, long charging time, and short service life. To improve the overall performance of electric motorcycles, connecting multiple battery packs in parallel has become an effective solution. However, traditional parallel battery connection methods have technical difficulties such as uneven load between batteries, system overheating, and low charging and discharging efficiency. Therefore, in view of the above situation, there is an urgent need to develop an intelligent balancing management system and control method for multiple parallel lithium batteries to overcome the shortcomings in current practical applications. Summary of the Invention

[0003] The purpose of the present invention is to provide an intelligent balancing management system and control method for multiple groups of parallel lithium batteries, which can enable multiple groups of batteries to be connected in parallel when in use. Each group of batteries is intelligently monitored and balanced by the battery management system to ensure that the voltage and capacity of the batteries remain consistent. The output power of each group of batteries is balanced through a precise current distribution module to solve the problems raised in the above background technology.

[0004] To achieve the above object, the present invention provides the following technical solutions:

[0005] An intelligent balancing management system for multiple parallel lithium batteries, comprising: multiple parallel battery packs, a BMS and a current distribution module;

[0006] The BMS includes:

[0007] Multi-channel monitoring unit, used to collect voltage, temperature and current parameters of each battery group in real time;

[0008] The dynamic balancing control unit adjusts the load between battery groups based on monitoring data to keep the voltage and capacity of each battery group consistent;

[0009] Protect the execution unit and cut off the circuit when the voltage is abnormal or the temperature exceeds the limit;

[0010] The current distribution module evenly distributes the output current of each battery group according to the BMS instruction.

[0011] As a further solution of the present invention, it also includes: a thermal management module, which uses PCM and heat pipes filled in the gaps between battery cells to absorb and conduct battery heat.

[0012] As a further solution of the present invention, it also includes: an intelligent charging module for dynamically adjusting the charging current and voltage according to the battery charging status.

[0013] As a further solution of the present invention: the battery pack adopts a modular structure to support independent maintenance or replacement.

[0014] As a further solution of the present invention: the parallel connection method of the battery pack is: the positive poles of multiple battery groups are connected in parallel to the positive pole of the main circuit, and the negative poles are connected in parallel to the negative pole of the main circuit; the discharge signal lines of each battery pack are connected in parallel to the load.

[0015] An intelligent balancing control method for multiple parallel lithium battery groups is applied to the intelligent balancing management system for multiple parallel lithium battery groups described above, comprising:

[0016] Real-time monitoring steps: obtain the voltage, temperature and current parameters of each battery group through a multi-channel monitoring unit;

[0017] Dynamic balancing step: compare the voltage and capacity differences of each battery group, adjust the output current through the current distribution module to achieve load balancing;

[0018] Safety protection steps: When it is detected that the voltage is lower than the threshold, higher than the threshold, or the temperature exceeds the limit, the battery circuit is cut off.

[0019] As a further solution of the present invention: in the dynamic balancing step: the load is dynamically distributed according to the actual demand of the battery, so that the voltage fluctuation range is controlled within ±0.8V.

[0020] As a further solution of the present invention, it also includes: a thermal management step: absorbing the heat of the battery core through the PCM and accelerating the heat dissipation through the heat pipe.

[0021] As a further solution of the present invention, it also includes: an intelligent charging step: dynamically adjusting the charging current and voltage according to the battery status during the charging process to prevent overcharging.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] 1. Flexible expansion: supports parallel connection of any number of battery packs, and the driving range can be increased as needed;

[0024] 2. Safe and reliable: Dynamic balancing and fuse protection are used to resolve the risks of multiple parallel connections;

[0025] 3. Power improvement: Multiple battery groups can share the load power; multiple battery groups connected in parallel can easily handle high-power loads. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a schematic diagram of the intelligent balancing management system for multiple parallel lithium batteries in an embodiment of the present invention. DETAILED DESCRIPTION

[0027] The following will provide a clear and complete description of the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0028] The specific implementation of the present invention is described in detail below with reference to specific embodiments.

[0029] See also Figure 1 The present invention provides an intelligent balancing management system for multiple parallel lithium battery groups. This allows multiple groups of batteries to be connected in parallel during use. Each group of batteries is intelligently monitored and balanced by a battery management system (BMS), ensuring that the battery voltage and capacity remain consistent. The precise current distribution module also balances the output power of each group of batteries. The details are as follows:

[0030] Multiple battery packs, each of which is intelligently monitored and balanced by a BMS. The BMS ensures that the voltage and capacity of each battery pack remain consistent, and balances the output power of each battery pack through a current distribution module.

[0031] The BMS uses multi-channel monitoring technology to monitor the voltage, temperature, current and other parameters of each battery group in real time, and dynamically adjust the load between battery groups according to the actual needs of the battery;

[0032] Balancing function: Balancing current 20mA, balanced starting voltage difference ≥50mV, effectively extending the life of the battery cell;

[0033] Voltage monitoring: Overcharge protection voltage 4.25V / single cell, over-discharge protection voltage 3.1V / single cell. When the threshold is reached, the BMS will automatically stop charging or discharging;

[0034] Temperature monitoring: The current discharge protection value of each group is 80A. When the discharge protection current threshold is reached, the discharge will stop automatically.

[0035] Dynamic temperature control protection: charging over-temperature protection (55℃±5℃), discharging under-temperature protection (-20℃±5℃), supporting discharge in a wide temperature range of -20℃ to 55℃;

[0036] Charging over-temperature protection: triggered at 55℃±5℃, restored when the temperature drops to 50℃±5℃;

[0037] Discharge under-temperature protection: triggered at -20℃±5℃, restored when the temperature rises to -14℃±5℃;

[0038] Built-in NTC temperature sensor to monitor the battery surface and ambient temperature in real time;

[0039] Current protection: This series of BMS uses an AFE to detect current. Both the MCU and AFE provide current protection for the BMS. The AFE provides two levels of protection for discharge overcurrent; the MCU provides one level of protection for charge overcurrent and two levels of protection for discharge overcurrent. Please confirm with the charger and controller manufacturers whether the protection parameters are reasonable, otherwise, charging may be accidentally disconnected during use.

[0040] Four-level overcurrent protection: including level 1 overcurrent (80A / 10s), level 2 overcurrent (90A / 1s), level 3 overcurrent (100A / 320ms), and short-circuit protection (505A / 300μs). Collaborative detection between the AFE and MCU ensures rapid disconnection.

[0041] The system also includes an efficient thermal management system that uses thermally conductive materials to ensure the battery pack's temperature is effectively controlled during high power output to prevent overheating. Paraffin-based phase change material (PCM) is filled between the battery cells to absorb heat and slow temperature rise during high temperatures.

[0042] It also includes an intelligent charging module that automatically determines the battery's charging status during charging and adjusts the charging current and voltage according to the battery's needs to improve charging efficiency and prevent overcharging;

[0043] Among them, the BMS parameter settings are: overcharge protection voltage 4.25V / single cell, over-discharge protection voltage 3.1V / single cell, and the protection threshold is adjusted through the host computer.

[0044] The system adopts a modular design, and each battery pack can be maintained and replaced independently, making it easy for users to expand or replace battery packs according to their needs;

[0045] like Figure 1 As shown, users can expand or replace battery packs as needed. The positive poles of multiple battery packs are connected in parallel to the positive pole of the main circuit, and the negative poles are connected in parallel to the negative pole of the main circuit; the discharge signal lines of each battery pack are connected in parallel and then connected to the load.

[0046] The BMS also includes a protection function for cutting off the battery circuit when the battery voltage is too low, too high, or the temperature is abnormal, to ensure safe operation of the battery;

[0047] Among them, the BMS parameter settings are: overcharge protection voltage 4.25V / single cell, over-discharge protection voltage 3.1V / single cell, and the protection threshold is adjusted through the host computer.

[0048] The battery packs are connected in parallel to the main circuit, and the current distribution module ensures balanced current distribution between the battery packs. During use, the positive and negative poles of multiple battery packs can be connected in parallel and then connected to the load. The discharge signal lines of each battery are connected in parallel to the positive pole of the battery, and the discharge signal lines (CNCT) are connected in parallel and then connected to the load.

[0049] Specifically, the intelligent balancing management system of multiple parallel lithium batteries of the present invention significantly improves battery performance and user experience by optimizing the parallel mode and management system of the battery pack. In order to verify the superiority of the technical solution, systematic tests were carried out on core indicators such as endurance, thermal management efficiency, charging efficiency and maintenance convenience. In the endurance test, an electric motorcycle equipped with 3 parallel lithium batteries (single group capacity 20Ah, total capacity 60Ah) traveled at a constant speed of 60km / h on a flat road, and the cruising range reached 134 kilometers, which is 185.1% higher than the traditional single group lithium battery (47 kilometers). Through the dynamic balancing technology of BMS, the voltage and load distribution of each group of batteries are monitored and adjusted in real time. The voltage fluctuation range is reduced from ±3.5V of the traditional solution to ±0.8V, a reduction of 77%, ensuring stable power output and significantly improving power performance and endurance consistency.

[0050] To address the thermal management issues in high-load scenarios, this solution uses PCM filling and heat pipe heat dissipation technology. In an extreme test of climbing a 15° slope for 30 minutes, the surface temperature of the traditional battery pack rose to 85°C within 30 minutes and triggered overheating protection. However, the battery pack of the present invention absorbed heat through PCM and quickly conducted heat through the heat pipe, and the temperature only rose to 53°C. The temperature rise rate dropped from 5.3°C / min to 2.1°C / min, a 60% decrease, and the protection mechanism was not triggered, verifying the reliability of the thermal management system. The intelligent charging module dynamically adjusts the current and voltage to shorten the charging time from 0 to 80% from 120 minutes of the traditional constant current and constant voltage strategy to 75 minutes, and the efficiency is improved by 37.5%. After 500 deep charge and discharge cycles, the capacity retention rate still reached 92%, an increase of 18% over the traditional solution (78%), and no overcharge or over-discharge accidents occurred throughout the process, fully demonstrating the synergistic advantages of intelligent charging and multiple protection functions.

[0051] In terms of maintenance convenience, the modular design significantly improves the efficiency of battery pack replacement. When simulating the failure of the second group of battery cells, the BMS system can accurately locate the fault and trigger an alarm within 5 seconds. The user can complete the replacement operation independently in just 3 minutes, and the system will resume operation immediately. Traditional integrated batteries need to be returned to the factory for repair and it takes up to 72 hours. This design improves maintenance efficiency by more than 90%, greatly reducing user downtime costs. In addition, multi-level safety protection mechanisms (such as voltage anomaly cut-off and temperature monitoring) further ensure the safety of system operation and achieve a zero accident rate. Therefore, this solution comprehensively solves the problems of limited capacity, large power fluctuations, low charging efficiency and complex maintenance of traditional lithium batteries through dynamic balancing, intelligent thermal management, efficient charging and modular design, providing electric motorcycles with a high-endurance, high-safety and long-life energy solution with significant market competitiveness and technological advancement.

[0052] In summary, the present invention solves the problems of limited capacity, limited power, long charging time and short service life in existing lithium batteries by optimizing the parallel connection mode of battery packs. Multiple groups of batteries can be connected in parallel when in use. Each group of batteries is intelligently monitored and balanced by the BMS to ensure that the voltage and capacity of the batteries remain consistent, and the output power of each group of batteries is balanced through a precise current distribution module. In addition, efficient thermal management and charge and discharge management technologies are introduced to effectively improve the safety, charging efficiency and service life of the batteries. The modular design further enhances the flexibility and maintainability of the system. This lithium battery is suitable for electric motorcycles and can significantly improve the endurance, power output and safety of electric motorcycles.

[0053] It should be noted that, in the present invention, it should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. An intelligent balancing management system for multiple parallel lithium batteries, characterized in that: include: Multiple parallel battery packs, BMS and current distribution modules; The BMS includes: Multi-channel monitoring unit, used to collect voltage, temperature and current parameters of each battery group in real time; The dynamic balancing control unit adjusts the load between battery groups based on monitoring data to keep the voltage and capacity of each battery group consistent; Protect the execution unit and cut off the circuit when the voltage is abnormal or the temperature exceeds the limit; The current distribution module evenly distributes the output current of each battery group according to the BMS instruction.

2. The intelligent balancing management system for multiple parallel lithium batteries according to claim 1, characterized in that: Also includes: The thermal management module uses PCM and heat pipes filled in the gaps between battery cells to absorb and conduct battery heat.

3. The intelligent balancing management system for multiple parallel lithium batteries according to claim 1, characterized in that: Also includes: The intelligent charging module is used to dynamically adjust the charging current and voltage according to the battery charging status.

4. The intelligent balancing management system for multiple parallel lithium batteries according to claim 1, characterized in that: The battery pack adopts a modular structure and supports independent maintenance or replacement.

5. The intelligent balancing management system for multiple parallel lithium batteries according to claim 4, characterized in that: The battery packs are connected in parallel in the following manner: the positive electrodes of the multiple battery packs are connected in parallel to the positive electrode of the main circuit, and the negative electrodes are connected in parallel to the negative electrode of the main circuit; and the discharge signal lines of the battery packs are connected in parallel to the load.

6. An intelligent balancing control method for multiple parallel lithium batteries, characterized in that: An intelligent balancing management system for multiple parallel-connected lithium batteries according to any one of claims 1 to 5, comprising: Real-time monitoring steps: obtain the voltage, temperature and current parameters of each battery group through a multi-channel monitoring unit; Dynamic balancing step: compare the voltage and capacity differences of each battery group, adjust the output current through the current distribution module to achieve load balancing; Safety protection steps: When it is detected that the voltage is lower than the threshold, higher than the threshold, or the temperature exceeds the limit, the battery circuit is cut off.

7. The intelligent balancing control method for multiple parallel lithium batteries according to claim 6, characterized in that: In the dynamic balancing step: the load is dynamically distributed according to the actual demand of the battery so that the voltage fluctuation range is controlled within ±0.8V.

8. The intelligent balancing control method for multiple parallel lithium batteries according to claim 6, characterized in that: Also includes: Thermal management steps: The PCM absorbs the heat of the battery cell and accelerates the heat dissipation through the heat pipe.

9. The intelligent balancing control method for multiple parallel lithium batteries according to claim 6, characterized in that: Also includes: Intelligent charging steps: Dynamically adjust charging current and voltage according to battery status during charging to prevent overcharging.

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