A BMS unit, battery pack and battery cabinet and cabinet management system

Abstract

The utility model discloses a kind of BMS unit, battery pack and battery cabinet and cabinet management system.The BMS unit includes MCU, isolation RS485 transceiver circuit and at least three-way isolation CAN transceiver circuit, wherein three-way CAN passage is used to communicate with host computer and battery cabinet in chain-like cascade communication respectively, and RS485 passage is used for networking between battery cabinet.Electric battery pack integrates the BMS unit and battery module, and constitutes minimum management unit.Multiple battery packs are connected in series to form chain-like network through second, third CAN passage, first node is connected as communication host computer with host computer, and each battery cabinet communication host computer is interconnected through RS485.The utility model solves the signal interference problem under the complex networking of battery system through multistage isolation communication architecture, supports modular extension and improves system stability.

Description

Technical Field

[0001] This utility model relates to the field of battery energy storage management technology, and in particular to a BMS unit, battery pack and battery cabinet parallel management system. Background Technology

[0002] In the field of energy storage, to meet the need for larger capacity energy storage modules, multiple battery packs are usually connected in series to form a battery cabinet, and then the battery cabinets are connected in parallel. Since each battery pack has a BMS board, and multiple BMS are connected in communication before being connected in parallel, the stability and timeliness of communication are particularly important. Utility Model Content

[0003] This utility model aims to provide a BMS unit, battery pack, and battery cabinet parallel management system based on multi-channel isolated communication, solving the signal interference problem under complex battery system networking, supporting modular expansion, and improving system stability. The technical solution is as follows:

[0004] A BMS unit for use in a battery pack includes an MCU, at least one isolated RS485 transceiver circuit and at least three isolated CAN transceiver circuits;

[0005] The MCU transmits and receives three sets of CAN-Tx / CANRx signals through the three-channel isolated CAN transceiver circuit. The first channel is used to communicate with the host computer, and the second and third channels are used to connect with the upper and lower battery packs in the same battery cabinet in a chain communication manner.

[0006] The MCU transmits and receives a set of RS485 differential signals through the isolated RS485 transceiver circuit, which is used to realize the communication connection between battery cabinets.

[0007] Furthermore, the isolated RS485 transceiver circuit includes a first digital isolation chip and an RS485 transceiver chip;

[0008] The first digital isolation chip includes two forward channels and one backward channel. Its input side is connected to the MCU, and its output side is connected to the RS485 transceiver chip. The first forward channel is used to transmit the RS485 transmit data signal of the MCU, the second forward channel is used to transmit the transmit enable control signal of the MCU, and the backward channel is used to transmit the RS485 receive data signal to the MCU.

[0009] The RS485 transceiver chip is a MAX485 or a compatible chip. Its transmit enable and receive enable terminals are both connected to the transmit enable control signal output by the second forward channel. The transmit enable control signal line is grounded through a pull-down resistor, and the level output by the second forward channel is controlled by the MCU to switch the transmit and receive states.

[0010] Furthermore, the isolated CAN transceiver circuit includes a second digital isolation chip and a CAN transceiver chip;

[0011] The second digital isolation chip includes a forward channel and a backward channel; its input side is connected to the MCU, and its output side is connected to the CAN transceiver chip, wherein the forward channel is used to transmit the CAN transmit data signal of the MCU, and the backward channel is used to transmit the CAN receive data signal to the MCU;

[0012] The CAN transceiver chip is SIT1044 or a compatible chip.

[0013] A battery pack includes a battery module and a BMS unit, the BMS unit being electrically connected to the battery module to monitor its status.

[0014] A battery cabinet parallel management system includes multiple battery cabinets, each battery cabinet containing multiple battery packs, and each battery pack is connected in series through the second and third isolated CAN transceiver circuits of the BMS unit to form a chain-like communication network.

[0015] In the chain-like communication network, the first battery pack is defined as the communication host, and the first isolated CAN transceiver circuit of its BMS unit is connected to the host computer.

[0016] The communication hosts of each battery cabinet are interconnected through the isolated RS485 transceiver circuit of the BMS unit.

[0017] This utility model has the following beneficial effects:

[0018] This invention solves the signal interference problem in complex battery system networking through a multi-level isolated communication architecture, supports modular expansion, and improves system stability. Attached Figure Description

[0019] Figure 1 This is a system block diagram of a battery energy storage system based on the energy storage device unit of this utility model;

[0020] Figure 2 This is a block diagram of the battery pack BMS of this utility model;

[0021] Figure 3 This is a circuit diagram of the isolated CAN transceiver circuit of this utility model;

[0022] Figure 4 This is a circuit diagram of the isolated RS485 transceiver circuit of this utility model. Detailed Implementation

[0023] To further illustrate the various embodiments, the present invention provides accompanying drawings. These drawings are part of the disclosure of the present invention and are mainly used to illustrate the embodiments, and can be used in conjunction with the relevant descriptions in the specification to explain the operating principles of the embodiments. With reference to these drawings, those skilled in the art should be able to understand other possible implementations and the advantages of the present invention. Components in the drawings are not drawn to scale, and similar component symbols are generally used to represent similar components.

[0024] The present invention will now be further described in conjunction with the accompanying drawings and specific embodiments.

[0025] like Figure 1 As shown, this utility model presents a parallel management system for battery cabinets based on multi-channel isolated communication. This system manages multiple battery cabinets uniformly through a multi-level isolated communication architecture, and monitors the status data of each battery pack in each cabinet in real time. The BMS (Battery Management System) of each battery pack in each cabinet is connected in series via a CAN bus to form a chain-like communication network. The first battery pack in the chain-like communication network is defined as the communication host, such as PACK1, and its BMS is connected to the host computer via a CAN transceiver circuit. The communication hosts of each battery cabinet are interconnected through the RS485 transceiver circuit of the BMS.

[0026] Each battery pack contains a BMS module that monitors the voltage and temperature of individual battery cells in real time, controls the charging and discharging process of each cell, balances the voltage difference between each cell, and reports the status of each battery cell in real time.

[0027] The battery packs in each battery cabinet are connected in series or in parallel as needed to meet the requirements of high current or high voltage output.

[0028] Through the parallel management system for battery cabinets, when the communication host PACK1 of each battery cabinet is powered on, it can wake up other battery packs in sequence through the chain communication network to complete operations such as power-on and ID configuration, and upload the status data of all battery packs in the battery cabinet to the host computer in real time.

[0029] Through the parallel management system for battery cabinets, the communication host PACK1 of each battery cabinet can serve as the main host of the parallel management system. The main host can perform operations such as powering on and configuring IDs for each communication host, thereby realizing one-click power-on and global ID configuration functions.

[0030] When multiple battery packs are connected in series, each battery pack has a negative terminal, resulting in different reference grounds for each BMS. Therefore, communication stability needs to be addressed when battery packs are connected in series. Similarly, because battery cabinets have different reference grounds, communication stability needs to be addressed when battery cabinets are connected in parallel.

[0031] like Figure 2As shown, in order to achieve as Figure 1 The diagram illustrates a parallel management system for battery cabinets. This invention provides a BMS communication architecture based on multi-channel isolated communication. The BMS includes an MCU, at least one isolated RS485 transceiver circuit, and at least three isolated CAN transceiver circuits. The MCU transmits and receives three sets of CAN-Tx / CANRx signals through the three isolated CAN transceiver circuits. The first CAN signal is used for communication with a host computer, while the second and third CAN signals are used for chain-like communication connections with upper and lower battery packs within the same battery cabinet. The MCU also transmits and receives one set of RS485 differential signals through the isolated RS485 transceiver circuits to achieve communication connections between battery cabinets.

[0032] Figure 3 An example of an isolated CAN transceiver circuit for a BMS is given. The main components include a digital isolation chip U7 and a CAN transceiver chip U8. The MCU's serial port signals PB6_CAN2_TX and PB5_CAN2_RX first pass through the digital isolation chip U7, where the reference ground is isolated from the original GND to AGND, and then enters the CAN transceiver chip U8, which converts the serial port signals into CAN signals CAN2_H / CAN2_L.

[0033] In this embodiment, the digital isolation chip U7 is a CA-IS3721HS or a compatible model, meeting the requirement of having one forward channel and one backward channel. The CAN transceiver chip U8 is a SIT1044 or a compatible model.

[0034] Figure 4 An embodiment of an isolated RS485 transceiver circuit for a BMS is given. The main components include a digital isolation chip U12 and an RS485 transceiver chip U13. The MCU's UART serial port signals PA9_RS485_TX1 and PA10_RS485_RX1 first pass through the digital isolation chip U12, where the reference ground is isolated from the original GND to AGND, and then enters the RS485 transceiver chip U13, which converts the serial port signals into RS485 differential signals RS485_1_A and RS485_1_B for parallel communication. In this embodiment, the MCU's RS485 enable signal PA9_RS485_EN also needs to pass through the isolation chip U12 before being given to the RS485 transceiver chip U13 to control the transmission and reception of RS485 signals.

[0035] In this embodiment, the digital isolation chip U12 uses PAI141U31 or a compatible chip, meeting the requirement of having two forward channels and one backward channel. The RS485 transceiver chip U13 uses MAX485 or a compatible chip (such as TPS485). Its transmit enable terminal DE and receive enable terminal / RE are connected to the transmit enable control signal RS485_EN1 output by a forward channel. The transmit enable control signal line is grounded through a pull-down resistor, and the output level of this forward channel is controlled by the MCU to switch the transmit and receive states, so that the RS485 transceiver chip U13 operates in half-duplex mode, achieving communication stability.

[0036] In summary, this utility model solves the signal interference problem in complex battery system networking through a multi-level isolated communication architecture, enabling one-click power-on and global ID configuration, supporting modular expansion and improving system stability.

[0037] Although the present invention has been specifically shown and described in conjunction with preferred embodiments, those skilled in the art should understand that various changes in form and detail may be made to the present invention without departing from the spirit and scope of the present invention as defined in the appended claims, and all such changes shall be within the scope of protection of the present invention.

Claims

1. A BMS unit, applied to a battery pack, characterized in that, Includes an MCU, at least one isolated RS485 transceiver circuit, and at least three isolated CAN transceiver circuits; The MCU transmits and receives three sets of CAN-Tx / CANRx signals through the three-channel isolated CAN transceiver circuit. The first channel is used to communicate with the host computer, and the second and third channels are used to connect with the upper and lower battery packs in the same battery cabinet in a chain communication manner. The MCU transmits and receives a set of RS485 differential signals through the isolated RS485 transceiver circuit, which is used to realize the communication connection between battery cabinets.

2. The BMS unit as described in claim 1, characterized in that, The isolated RS485 transceiver circuit includes a first digital isolation chip and an RS485 transceiver chip; The first digital isolation chip includes two forward channels and one backward channel. Its input side is connected to the MCU, and its output side is connected to the RS485 transceiver chip. The first forward channel is used to transmit the RS485 transmit data signal of the MCU, the second forward channel is used to transmit the transmit enable control signal of the MCU, and the backward channel is used to transmit the RS485 receive data signal to the MCU. The RS485 transceiver chip is a MAX485 or a compatible chip. Its transmit enable and receive enable terminals are both connected to the transmit enable control signal output by the second forward channel. The transmit enable control signal line is grounded through a pull-down resistor, and the level output by the second forward channel is controlled by the MCU to switch the transmit and receive states.

3. The BMS unit as described in claim 1, characterized in that, The isolated CAN transceiver circuit includes a second digital isolation chip and a CAN transceiver chip; The second digital isolation chip includes a forward channel and a backward channel; Its input side is connected to the MCU, and its output side is connected to the CAN transceiver chip. The forward channel is used to transmit the CAN data signal sent by the MCU, and the backward channel is used to transmit the CAN data signal received to the MCU. The CAN transceiver chip is SIT1044 or a compatible chip.

4. A battery pack, characterized in that, It includes a battery module and a BMS unit as described in any one of claims 1-3, wherein the BMS unit is electrically connected to the battery module to monitor its status.

5. A battery cabinet parallel management system, characterized in that, It includes multiple battery cabinets, each containing multiple battery packs as described in claim 4, and each battery pack is connected in series through the second and third isolated CAN transceiver circuits of the BMS unit to form a chain-like communication network; In the chain-like communication network, the first battery pack is defined as the communication host, and the first isolated CAN transceiver circuit of its BMS unit is connected to the host computer. The communication hosts of each battery cabinet are interconnected through the isolated RS485 transceiver circuit of the BMS unit.

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