Real-time parallel self-adaptive lithium battery pack device

Abstract

The utility model provides a real-time parallel self-adaptive lithium battery pack device, which comprises a plurality of lithium battery packs connected in parallel, each lithium battery pack comprises a main circuit and a control circuit, and the main circuit comprises a lithium battery, a secondary protection circuit, a main switch circuit, a balance circuit and an auxiliary power supply. The lithium battery is connected with the battery output terminal after sequentially passing through the secondary protection circuit, the main switch circuit and the balance circuit, the control circuit comprises an MCU and an isolation communication circuit, and the MCU is connected with isolation communication circuits of other lithium battery packs through the isolation communication circuit and feeds back a driving signal to the main switch circuit. And the auxiliary power supply takes electricity from the lithium battery and supplies power to the MCU and the isolation communication circuit. In conclusion, according to the real-time parallel self-adaptive lithium battery pack device provided by the utility model, not only is the intelligent level of parallel use of the battery packs improved, but also the safety, the reliability and the user friendliness of the system are remarkably enhanced.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of lithium battery packs, in particular to a real-time parallel adaptive lithium battery pack device. BACKGROUND

[0002] In modern society, with the rapid progress of technology and the increasing expansion of industrial production, the power system has become a key infrastructure supporting the normal operation of the entire society. With the popularity of various electronic devices and electric vehicles, people's demand for electric energy has increased dramatically, which puts higher requirements on the performance of energy storage devices. Although traditional lead-acid batteries have a long history and mature technology, they have been difficult to meet the current application requirements of high energy density, miniaturization and long endurance due to their low energy density, large size, limited cycle life and other shortcomings. Therefore, lithium-ion batteries have gradually become the mainstream choice to replace lead-acid batteries due to their high energy density, long cycle life, low self-discharge rate and other advantages.

[0003] However, even though lithium batteries have significantly improved in performance, they are often insufficient in the face of extremely high requirements for energy storage capacity in specific application scenarios. In order to improve the overall energy storage capacity, a common solution is to use battery pack parallel connection technology, that is, by connecting multiple lithium battery packs in parallel to increase the total capacity and meet high load demands. However, this parallel operation is not simply connecting the battery packs in parallel physically, it requires that all battery packs participating in parallel connection must have strict specification consistency, including voltage level, capacity size, etc., and before use, it is necessary to ensure that each battery pack has been fully charged to the same state to avoid current imbalance caused by voltage difference or capacity difference, thereby causing battery overheating, damage and even safety accidents.

[0004] In actual operation, precise control to achieve the above conditions requires a high level of professional knowledge from the user, and ordinary users often cannot accurately judge the matching degree of the battery pack and correctly perform the preparation work before parallel connection. If different state lithium battery packs are directly connected in parallel without proper processing, it may not only lead to reduced battery performance and shortened service life, but also cause internal short circuit, thermal runaway and even explosion of the battery pack in severe cases, which seriously threatens personnel safety and property safety. CONTENT OF THE INVENTION

[0005] The present application provides a real-time parallel adaptive lithium battery pack device, which aims to realize automatic detection, matching and balancing control of parallel battery packs through an intelligent control system built-in, thereby effectively solving the problems existing in the prior art.

[0006] In order to achieve the above purpose, the present application provides the following technical solutions:

[0007] The application discloses a real-time parallel adaptive lithium battery pack device, which comprises a plurality of parallel lithium battery packs, wherein each lithium battery pack comprises a main circuit and a control circuit; the main circuit comprises a lithium battery, a secondary protection circuit, a main switch circuit, a balancing circuit and an auxiliary power supply; the lithium battery is connected with a battery output terminal through the secondary protection circuit, the main switch circuit and the balancing circuit in sequence; the control circuit comprises an MCU and an isolation communication circuit; the MCU is connected with the isolation communication circuit of other lithium battery packs through the isolation communication circuit and feeds back a driving signal to the main switch circuit; and the auxiliary power supply takes power from the lithium battery and provides power supply for the MCU and the isolation communication circuit.

[0008] In one of the embodiments, the secondary protection circuit comprises a three-terminal fuse, and the lithium battery is connected with the main switch circuit and the balancing circuit through the three-terminal fuse.

[0009] In one of the embodiments, the main switch circuit comprises a first switch tube and a second switch tube; the first switch tube is connected with the second switch tube; and the second switch tube is further connected with the battery output terminal.

[0010] In one of the embodiments, the balancing circuit comprises a third switch tube, a fourth switch tube, a fifth switch tube and an inductor; the fifth switch tube is connected with the three-terminal fuse and further connected with the inductor; the third switch tube and the fourth switch tube are connected with the other end of the inductor; and the third switch tube is connected with the battery output terminal.

[0011] In one of the embodiments, the control circuit further comprises a sampling circuit, a driving module and a temperature protection circuit; the lithium battery is connected with the MCU through the sampling circuit; the main switch circuit and the balancing circuit are connected with the MCU through the sampling circuit; the lithium battery is connected with the MCU through the temperature protection circuit; the MCU is connected with the balancing circuit and the main switch circuit through the driving module; and the MCU is connected with the isolation communication circuit of other lithium battery packs through the isolation communication circuit.

[0012] In one of the embodiments, the model of the MCU is STM32C031C6T6.

[0013] The application has the following beneficial effects:

[0014] (1) The real-time communication and collaborative control among the plurality of lithium battery packs are realized through the built-in microcontroller (MCU) and the isolation communication circuit, which not only simplifies the complexity of the parallel operation of the traditional battery pack, but also significantly improves the intelligent level of the parallel process, so that the user can easily realize the parallel use of the battery pack without deep professional knowledge.

[0015] (2) The main circuit in the device is equipped with secondary protection circuit, main switch circuit and balance circuit. These circuits work together to accurately control the charging and discharging voltage of the lithium battery pack, and automatically adjust the power difference between each battery pack through the balance circuit to ensure that the voltage and capacity of all battery packs tend to be consistent. This feature effectively avoids the performance degradation and safety hazards of the battery pack caused by inconsistent voltage or capacity, prolonging the service life of the battery pack.

[0016] (3) The application can quickly identify and respond to abnormal conditions in the battery pack, such as overcharging, overdischarging, temperature abnormalities, etc., through real-time detection and communication, and MCU can take protective measures in time to prevent the battery pack from being damaged or causing safety accidents. In addition, the design of the isolation communication circuit also enhances the overall anti-interference ability of the system, improves the reliability and stability of the communication, and further ensures the safety of the parallel use of the battery pack.

[0017] (4) For most users, the device simplifies the operation process of parallel connection of the battery pack, and reduces the use threshold. Users do not need to worry about the risk of mismatched battery pack specifications or improper operation, and can realize the parallel use of the battery pack by following the simple instructions, and enjoy more convenient and safe energy supply experience. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 The circuit block diagram of the real-time parallel adaptive lithium battery pack device provided by an embodiment of the application is shown in the figure;

[0019] Figure 2 The circuit diagram of the real-time parallel adaptive lithium battery pack device provided by an embodiment of the application is shown in the figure; DETAILED DESCRIPTION

[0020] The terms used in the implementation part of the application are only used to explain the specific embodiments of the application, and are not intended to limit the application. The implementation of the embodiments of the application will be described in detail below with reference to the accompanying drawings.

[0021] As Figure 1 shown, the embodiment provides a real-time parallel adaptive lithium battery pack device, which includes a plurality of parallel connected lithium battery packs. Each lithium battery pack includes a main circuit and a control circuit.

[0022] Main circuit structure:

[0023] Lithium battery: high-voltage lithium battery is used as an energy storage unit.

[0024] Secondary protection circuit: Includes a three-terminal fuse F1, model Schott D6SE14-45, rated at 80V / 45A. The lithium battery is connected to the main switching circuit and balancing circuit via the three-terminal fuse F1, providing short-circuit protection and charging overvoltage protection. It serves as the next line of defense when other circuits in the lithium battery pack fail, resulting in ineffective charging control or short-circuit protection.

[0025] like Figure 2 The main switching circuit, as shown, includes a first switching transistor Q1 and a second switching transistor Q4. Switches Q1 and Q4 are connected, and Q4 is then connected to the battery output terminal. The MCU controls the battery discharge by controlling the switching transistors. When the MCU detects that this battery has the highest voltage among all parallel batteries, it will turn on switches Q1 and Q4, allowing the battery to discharge to the outside.

[0026] The balancing circuit includes a third switch Q2, a fourth switch Q3, a fifth switch Q5, and an inductor L1. Switch Q5 is connected to a three-terminal fuse F1, which in turn is connected to inductor L1. The midpoint of switches Q2 and Q3 is connected to the other end of inductor L1, and Q2 is connected to the battery output terminal. The balancing circuit, under the control of the MCU, achieves voltage balance between battery packs. When the MCU detects that the voltage of this battery pack is more than 1.5V lower than that of other lithium battery packs, it will continuously shut down Q1 and Q4, and turn on switches Q2 and Q6, putting the balancing voltage in BUCK mode to allow other lithium battery packs to charge this battery pack. Once the voltage and charge levels are equal, Q2 and Q6 will shut down again, and Q1 and Q4 will turn on.

[0027] Control circuit structure:

[0028] MCU: The STM32C031C6T6 is used, which is responsible for data processing, algorithm execution and control signal transmission.

[0029] Isolated communication circuit: This includes RS-485 and CAN communication circuits to enable information exchange and coordinated control between different lithium battery packs. The MCU in each lithium battery pack communicates with the MCUs of other lithium battery packs through this isolated communication circuit. During communication, each MCU sends its battery level, voltage, and other status information to the MCUs of other lithium battery packs. Upon receiving this information, each MCU calculates the average voltage and capacity of the entire battery pack using a specific algorithm and adjusts its own charging and discharging state to ensure that its voltage and capacity are consistent with the average value. The specific implementation method is as follows:

[0030] Voltage balancing: The voltage of each lithium battery pack is obtained through communication. By using components such as switches and inductors in the balancing circuit, some electrical energy in the lithium battery pack with higher voltage is transferred to the lithium battery pack with lower voltage, thereby achieving voltage balance.

[0031] Capacity balancing: During charging or discharging, by adjusting the charging and discharging current of each lithium battery pack, smaller capacity lithium battery packs receive more charging or less discharging, while larger capacity lithium battery packs receive less charging or more discharging, thereby achieving capacity balance.

[0032] Sampling circuit: Collects data such as voltage, current, temperature and capacity of the lithium battery pack and sends them to the MCU for processing.

[0033] The drive module, acting as a PWM controller, adjusts the switching state of the switching transistors according to the MCU's instructions, achieving precise control of the battery charging and discharging voltage. The MCU collects battery voltage and current data in real time through a sampling circuit, and this data is sent to the MCU for processing. The MCU has a pre-set algorithm that calculates the current battery charging and discharging state and the required voltage and current adjustments based on the collected voltage and current data. Then, the MCU sends control signals to the main switching circuit and the balancing circuit through the drive module to adjust the switching state of the switching transistors, thereby achieving precise control of the battery charging and discharging voltage.

[0034] Temperature protection circuit: Monitors the temperature of the lithium battery pack, and sends an alarm signal to the MCU when the temperature is too high, so that protective measures can be taken.

[0035] Working principle:

[0036] Voltage balancing: The MCU obtains the voltage information of each lithium battery pack through an isolated communication circuit and calculates the average voltage using an algorithm. When the voltage of a battery pack is higher or lower than the average voltage by a certain threshold (e.g., 1.5V), the MCU controls the switching transistors and inductors in the balancing circuit to transfer electrical energy and make the voltage more uniform.

[0037] Capacity balancing: During charging or discharging, the MCU adjusts the charging and discharging current of each battery pack based on the data collected by the sampling circuit, so that the battery pack with smaller capacity receives more charging or less discharging, while the battery pack with larger capacity receives the opposite, thereby achieving capacity balancing.

[0038] Safety protection: The secondary protection circuit, temperature protection circuit and MCU together form a multi-layer protection mechanism to ensure that the battery pack can respond quickly and take measures in abnormal situations to prevent safety accidents.

[0039] This embodiment takes a lithium battery pack with 16 series and 1 parallel, 51.2V, and 1000Wh as an example to illustrate the specific design of the main circuit parameters.

[0040] Secondary protection circuit parameters: Schott D6SE14-45 three-terminal fuse with specifications of 80V / 45A is selected to ensure that the circuit can be quickly cut off in the event of short circuit or overvoltage.

[0041] Inductance parameter: according to the working principle of the balance circuit and the control strategy of the MCU, the appropriate inductance value is selected to realize the smooth transfer of electric energy and the rapid adjustment of voltage.

[0042] Switching tube parameter: according to the voltage and current characteristics of the lithium battery pack and the control requirements of the MCU, the switching tube model capable of bearing the corresponding voltage and current is selected.

[0043] In the description of the embodiments of the present application, it should be pointed out that, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection" should be understood in a broad sense, for example, it can be fixed connection, or indirect connection through intermediate medium, or internal communication of two elements or interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0044] In the embodiments of the present application or the implied device or element must have a specific orientation, be constructed and operated in a specific orientation, so it cannot be understood as a limitation of the embodiments of the present application. In the description of the embodiments of the present application, the meaning of "a plurality of" is two or more than two, unless otherwise specified.

[0045] The terms "first", "second", "third", "fourth" and the like (if any) in the specification and claims of the embodiments of the present application and the above-described drawings are used to distinguish similar objects, and do not necessarily describe a specific order or sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances, so that the embodiments of the present application described herein, for example, can be implemented in an order other than those illustrated or described herein. In addition, the terms "may include" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device including a series of steps or units does not necessarily limit to those steps or units clearly listed, but can include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0046] Finally, it should be pointed out that: the above embodiments are only used to illustrate the technical solutions of the embodiments of the present application, but not to limit them. Although the embodiments of the present application have been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part or all of the technical features. The modification or replacement does not make the essence of the corresponding technical solution deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A real-time parallel adaptive lithium battery pack apparatus comprising a plurality of lithium battery packs in parallel, characterized by: The lithium battery pack comprises a main circuit and a control circuit, the main circuit comprises a lithium battery, a secondary protection circuit, a main switch circuit, a balancing circuit and an auxiliary power supply, the lithium battery is connected with a battery output terminal through the secondary protection circuit, the main switch circuit and the balancing circuit in sequence, the control circuit comprises an MCU and an isolation communication circuit, the MCU is connected with the isolation communication circuit of other lithium battery packs through the isolation communication circuit and feeds back a driving signal to the main switch circuit, and the auxiliary power supply takes power from the lithium battery and provides power supply for the MCU and the isolation communication circuit.

2. A real-time parallel adaptive lithium battery pack device according to claim 1, characterized in that: The secondary protection circuit comprises a three-terminal fuse, and the lithium battery is connected with the main switch circuit and the balancing circuit through the three-terminal fuse.

3. The real-time parallel adaptive lithium battery pack device according to claim 1, wherein: The main switch circuit comprises a first switch tube and a second switch tube, the first switch tube is connected with the second switch tube, and the second switch tube is further connected with the battery output terminal.

4. The real-time parallel adaptive lithium battery pack device according to claim 2, wherein: The balancing circuit comprises a third switch tube, a fourth switch tube, a fifth switch tube and an inductor, the fifth switch tube is connected with the three-terminal fuse and further connected with the inductor, the center point of the third switch tube and the fourth switch tube is connected with the other end of the inductor, and the third switch tube is connected with the battery output terminal.

5. The real-time parallel adaptive lithium battery pack device according to claim 1, wherein: The control circuit further comprises a sampling circuit, a driving module and a temperature protection circuit, the lithium battery is connected with the MCU through the sampling circuit, the main switch circuit and the balancing circuit are connected with the MCU through the sampling circuit, the lithium battery is connected with the MCU through the temperature protection circuit, the MCU is connected with the balancing circuit and the main switch circuit through the driving module, and the MCU is connected with the isolation communication circuit of other lithium battery packs through the isolation communication circuit.

6. The real-time parallel adaptive lithium battery pack device of claim 1, wherein: The model of the MCU is STM32C031C6T6.

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