Balancing device between single battery packs, battery pack and new energy automobile

Abstract

The utility model discloses a balancing device between single battery packs, a battery pack and a new energy automobile, and relates to the technical field of new energy automobiles, the balancing device comprises a BMS host, BMS slaves and an energy pool, each BMS slave controls a battery pack composed of a plurality of single batteries; the BMS host is independently connected with each BMS slave and is used for receiving battery pack parameter information uploaded by the BMS slave and issuing an equalization instruction to the BMS slave; the energy pool serves as an energy transfer relay and is used for storing or releasing electric energy; each BMS slave is connected with the energy pool and is used for transferring electric energy from the battery pack to the energy pool or acquiring electric energy from the energy pool by the battery pack; the equalizing current direction of the equalizing device is controllable, the inter-group equalization of the battery pack can be realized, the integration level is high, and the cost is low.

Description

Technical Field

[0001] This utility model relates to the field of new energy vehicle technology, and in particular to a single-cell battery pack equalization device, a battery pack, and a new energy vehicle. Background Technology

[0002] Battery cell balancing methods are divided into active balancing and passive balancing. Passive balancing is slow, inefficient, and generates a lot of heat. Active balancing is efficient, fast, and generates little heat, making it particularly suitable for applications requiring high balancing current.

[0003] The mainstream active balancing schemes can be divided into the following three types:

[0004] 1) Capacitor balancing: Capacitors are used to store the higher-voltage electrical energy in the battery pack. When a lower-voltage battery in the pack needs energy, the energy is released through the capacitor, thus maintaining the voltage of each individual cell in the pack. Capacitor balancing technology has high energy utilization efficiency, but it requires a large capacitor device, the balancing direction is uncontrollable, the balancing current is small when the voltage difference is low, and it cannot achieve inter-pack balancing.

[0005] 2) Inductor equalization: Inductors are used to store the higher-voltage energy in the battery pack. When a lower-voltage battery in the pack needs energy, the energy is released through the inductor, thus maintaining the voltage of each individual battery in the pack. Inductor equalization technology has high energy utilization efficiency, but it requires a large inductor device, the equalization direction is uncontrollable, the equalization current is small when the voltage difference is low, and it cannot achieve inter-pack equalization.

[0006] 3) Multi-tap transformer balancing: Multi-tap transformers are used to transfer the higher voltage energy from the batteries to the total voltage of the battery pack, and then transfer the total voltage energy to the lower voltage batteries to achieve balancing. Multi-tap transformer balancing technology can efficiently transfer electrical energy from high-voltage batteries to low-voltage batteries in the battery pack, but the device is more complex, the balancing direction is uncontrollable, and the balancing current is small when the voltage difference is low.

[0007] Therefore, the existing active balancing methods have the following problems: (1) The balancing module is large and complex, resulting in low adaptability, high cost and low reliability; (2) The balancing direction is uncontrollable and the balancing current is small when the voltage difference is low; (3) Inter-group balancing is not possible. Utility Model Content

[0008] Based on the technical problems existing in the background technology, this utility model proposes a single-cell battery pack equalization device, a battery pack, and a new energy vehicle, which enables controllable equalization current direction and realizes equalization between battery packs.

[0009] This invention proposes a battery pack equalization device, comprising a BMS master unit, a BMS slave unit, and an energy pool. Each BMS slave unit controls a battery pack composed of multiple battery cells. The BMS master unit is independently connected to each BMS slave unit and is used to receive battery pack parameter information uploaded by the BMS slave unit and to issue equalization commands to the BMS slave unit. The energy pool acts as an energy transfer relay for storing or releasing electrical energy. Each BMS slave unit is interconnected with the energy pool for transferring electrical energy from the battery pack to the energy pool or for the battery pack to obtain electrical energy from the energy pool.

[0010] Furthermore, the BMS slave includes an MCU, a battery sampling chip, and a digital isolator 3; the battery sampling chip is used to acquire the parameter information of the battery pack and upload the parameter information to the MCU through the digital isolator 3, and the MCU uploads the parameter information to the BMS host.

[0011] Furthermore, the MCU uploads the parameter information to the BMS host via a CAN transceiver.

[0012] Furthermore, the BMS slave also includes a driver, a digital isolator 2, and a MOSFET switch matrix; the MCU, digital isolator 2, driver, and MOSFET switch matrix are connected in sequence. The MCU transmits the equalization command received from the BMS master to the driver, and the driver controls the MOSFET switch matrix to open the equalization channel connected to the battery pack.

[0013] Furthermore, the BMS slave also includes a controller, a forward switching power supply module, and a digital isolator 1; the driver is connected to the controller, one output of the controller is connected to the secondary side of the forward switching power supply module, and the other output is connected to the primary side of the forward switching power supply module through the digital isolator 1. The secondary side of the forward switching power supply module is connected to the MOSFET switching matrix; the controller drives the forward switching power supply module to start the equalization operation to realize the power exchange between the battery pack and the energy pool.

[0014] Furthermore, the MCU receives equalization commands from the BMS host via the CAN transceiver.

[0015] Furthermore, the energy pool is a storage battery.

[0016] A battery pack, wherein the individual battery cells in the battery pack employ an inter-cell battery equalization device as described above.

[0017] A new energy vehicle includes a vehicle body and a battery pack disposed in the vehicle body, wherein the battery pack adopts the battery pack described above.

[0018] The advantages of the single-cell battery pack balancing device, battery pack, and new energy vehicle provided by this utility model are as follows: The single-cell battery pack balancing device, battery pack, and new energy vehicle provided in this utility model adopt a bidirectional energy transfer method to achieve active balancing, and combine existing balancing software control strategies suitable for lithium batteries to achieve inter-pack balancing of battery packs; based on the set channel foundation and drive foundation, the electrical energy transfer between the battery pack and the energy pool is realized, and inter-pack balancing of individual cells between battery packs can be performed. Thus, this embodiment achieves active balancing based on a bidirectional energy transfer method; based on active balancing, the balancing efficiency and balancing current are improved, and the direction of the balancing current is controllable. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of this utility model;

[0020] Figure 2 This is a schematic diagram of the BMS slave device.

[0021] Among them, 1-BMS master, 2-BMS slave, 3-energy pool. Detailed Implementation

[0022] The technical solution of this utility model will now be described in detail through specific embodiments. Many specific details are set forth in the following description to provide a thorough understanding of this utility model. However, this utility model can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the spirit of this utility model. Therefore, this utility model is not limited to the specific embodiments disclosed below.

[0023] like Figure 1 and 2 As shown, the present invention proposes a battery pack equalization device, comprising a BMS master unit 1, a BMS slave unit 2, and an energy pool 3. Each BMS slave unit 2 controls a battery pack composed of multiple battery cells. The BMS master unit 1 is independently connected to each BMS slave unit 2 and is used to receive battery pack parameter information uploaded by the BMS slave unit 2, and to issue equalization commands to the BMS slave unit 2. The energy pool 3 serves as an energy transfer relay for storing or releasing electrical energy. Each BMS slave unit 2 is interconnected with the energy pool 3 for transferring electrical energy from the battery pack to the energy pool 3, or for the battery pack to obtain electrical energy from the energy pool 3.

[0024] This embodiment employs a bidirectional energy transfer method to achieve active balancing, combining existing balancing software control strategies suitable for lithium batteries to realize inter-pack balancing. The system block diagram is as follows: Figure 1As shown, the balancing command is issued by BMS master 1, which allocates BMS slave 2 to balance specific cell positions (i.e., balance specific cells) according to the cell status. BMS slave A is in battery pack A, and BMS slave B is in battery pack B. The energy pool (battery) acts as an energy transfer relay, which can realize the energy transfer between cells in battery pack A and battery pack B, maintaining the consistency of cells throughout the vehicle.

[0025] In this embodiment, the BMS slave 2 includes an MCU, a battery sampling chip AFE, and a digital isolator 3. The battery sampling chip AFE is used to acquire the parameter information of the battery pack and upload the parameter information to the MCU through the digital isolator 3. The MCU uploads the parameter information to the BMS master 1, so that the BMS master 1 can acquire the parameter information of the battery pack in real time, namely, the single cell voltage, temperature, and other information. Here, AFE is an abbreviation for Active Front End, which refers to an active front end.

[0026] In this embodiment, the BMS slave 2 also includes a driver EMB1428, a digital isolator 2, a MOSFET switch matrix, a controller EMB1499, a forward switching power supply module, and a digital isolator 1.

[0027] The MCU, digital isolator 2, driver EMB1428, and MOSFET switch matrix are connected in sequence. The MCU transmits the equalization command received from the BMS host 1 to the driver EMB1428. The driver EMB1428 controls the MOSFET switch matrix to open the equalization channel connected to the battery pack, thereby providing a channel basis for the transfer of electrical energy between the battery pack and the energy cell 3.

[0028] The driver EMB1428 is connected to the controller EMB1499. One output of the controller EMB1499 is connected to the secondary side of the forward switching power supply module, and the other output is connected to the primary side of the forward switching power supply module through the digital isolator 1. The secondary side of the forward switching power supply module is connected to the MOSFET switching matrix. The controller EMB1499 drives the forward switching power supply module to start the equalization operation, thereby providing the driving basis for the power transfer between the battery pack and the energy cell 3.

[0029] Based on the aforementioned channel and driving foundations, the transfer of electrical energy between the battery pack and the energy pool is realized, and inter-pack balancing can be performed on individual cells within the battery pack. Thus, this embodiment achieves active balancing based on bidirectional energy transfer. Based on active balancing, the balancing efficiency and balancing current are improved, and the direction of the balancing current is controllable.

[0030] In this embodiment, the MCU of BMS slave 2 receives the equalization command issued by BMS master 1 through the CAN transceiver. In addition, the MCU uploads the parameter information to BMS master 1 through the CAN transceiver.

[0031] The driver EMB1428, controller EMB1499, and MOSFET switch matrix all adopt existing structures, and their internal structures will not be described in detail in this embodiment.

[0032] The functions of digital isolators 1, 2, and 3 are as follows: (a1) Improve system reliability and stability: Digital isolators isolate the electrical connection between input and output signals, preventing external noise and interference from affecting the system and ensuring its normal operation. (a2) Protect equipment and personnel safety: In some special environments, input signals may contain dangerous factors such as high voltage and high current. Digital isolators can effectively isolate these dangerous factors, ensuring the safety of equipment and personnel. (a3) ​​Improve signal transmission quality: By isolating the electrical connection between input and output signals, digital isolators can reduce interference and distortion that may occur during signal transmission, thereby improving the quality and accuracy of signal transmission. (a4) Electrical isolation: Digital isolators can effectively isolate high-voltage and low-voltage circuits, protecting low-voltage circuits from interference and damage caused by high-voltage circuits. (a5) Noise suppression: Through isolation, digital isolators can reduce electromagnetic interference (EMI) and radio frequency interference (RFI), improving signal integrity and reliability. (a6) Safety: In high-voltage applications, digital isolators can prevent safety hazards caused by high voltage to low-voltage parts, protecting equipment and personnel safety. (a7) Signal transmission: Digital isolators can transmit digital signals between different power domains, ensuring accurate data transmission.

[0033] Therefore, this embodiment can achieve bidirectional equalization of individual units and equalization between groups. At the same time, the circuit structure is simple and has high reliability, which greatly meets the various performance requirements of individual unit equalization. In addition, the component equalization device in this embodiment has high integration, low cost, and high reliability of automotive-grade components, which is conducive to design, production and application.

[0034] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. A single-cell battery pack equalization device, characterized in that, It includes a BMS master (1), a BMS slave (2) and an energy pool (3), and each BMS slave (2) controls a battery pack composed of multiple battery cells; The BMS host (1) is independently connected to each BMS slave (2) and is used to receive battery pack parameter information uploaded by the BMS slave (2) and to send equalization instructions to the BMS slave (2). The energy pool (3) serves as an energy transfer relay for storing or releasing electrical energy; Each BMS slave (2) is interconnected with the energy pool (3) for transferring electrical energy from the battery pack to the energy pool (3) or for the battery pack to obtain electrical energy from the energy pool (3).

2. The equalization device between individual battery packs according to claim 1, characterized in that, The BMS slave device (2) includes an MCU, a battery sampling chip, and a digital isolator 3; The battery sampling chip AFE is used to obtain the parameter information of the battery pack and upload the parameter information to the MCU through the digital isolator 3. The MCU then uploads the parameter information to the BMS host (1).

3. The equalization device between individual battery packs according to claim 2, characterized in that, The MCU uploads parameter information to the BMS host via the CAN transceiver (1).

4. The equalization device between individual battery packs according to claim 2, characterized in that, The BMS slave (2) also includes a driver, a digital isolator 2, and a MOSFET switch matrix; The MCU, digital isolator 2, driver, and MOS transistor switch matrix are connected in sequence. The MCU will pass the equalization command received from the BMS host (1) to the driver, and the driver will control the MOS transistor switch matrix to open the equalization channel connected to the battery pack.

5. The equalization device between individual battery packs according to claim 4, characterized in that, The BMS slave (2) also includes a controller, a forward switching power supply module, and a digital isolator 1; The driver EMB is connected to the controller. One output of the controller is connected to the secondary side of the forward switching power supply module, and the other output is connected to the primary side of the forward switching power supply module through the digital isolator 1. The secondary side of the forward switching power supply module is connected to the MOS transistor switching matrix. The controller drives the forward switching power supply module to start the equalization action to realize the power exchange between the battery pack and the energy pool (3).

6. The equalization device between individual battery packs according to claim 4, characterized in that, The MCU receives the equalization command sent by the BMS host (1) through the CAN transceiver.

7. The equalization device between individual battery packs according to claim 1, characterized in that, The energy pool (3) is a storage battery.

8. A battery pack, characterized in that, The individual cells in the battery pack employ the cell-to-cell equalization device as described in any one of claims 1 to 7.

9. A new energy vehicle, characterized in that, It includes a vehicle body and a battery pack disposed in the vehicle body, wherein the battery pack is the battery pack as described in claim 8.

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