Single-serial-port automatic switching circuit, BMS unit and energy storage device

Abstract

The invention discloses a single-serial-port automatic switching circuit, a BMS unit and an energy storage device. The circuit comprises an isolation power supply module, a digital isolation chip and a connector, the isolation power supply module supplies power to the wireless communication module and the digital isolation chip; the shell is provided with a forward channel and a reverse channel; the chip side of the BMS unit is connected with the processor of the BMS unit; the equipment side is connected with the wireless communication module and the connector; transmitting data of the processor to the wireless communication module after being forwarded through a forward channel of the digital isolation chip, and transmitting the data to the peripheral through the connector; and after the sending data of the wireless communication module passes through the first diode or the external sending data passes through the second diode, the sending data is transmitted to the processor of the BMS unit after being forwarded by the reverse channel of the digital isolation chip. The circuit ensures that a communication request is not interfered by a Bluetooth signal when the tool test fixture is communicated with a BMS (Battery Management System); when APP communication is verified, additional serial port disconnection and reconnection steps are not needed.

Description

Technical Field

[0001] The present invention relates to the field of electronic technology, and in particular to a single serial port automatic switching circuit, a BMS unit and an energy storage device. Background Art

[0002] As the market's requirements for the endurance and safety of new energy storage products continue to increase, the battery management system (BMS) is gradually gaining widespread attention and deep concern. BMS is known as the "core brain" of the power battery operating system, and its functional status is crucial. It is like the command center of the battery, responsible for receiving and sending information between the battery and external ports, and through in-depth analysis and fine processing of this information, it then issues instructions to execute work. The existence of BMS ensures the efficient and stable operation of the battery system, and provides solid technical support for the sustainable and healthy development of the new energy industry.

[0003] As an electronic device, BMS has extremely complex functions. During its design process, in order to ensure that its performance meets expectations, the functions of the prototype must be strictly verified. After entering the production stage, it is also crucial to conduct a comprehensive test of the product's functions to ensure the stability and reliability of product quality. Once the equipment fails, timely maintenance is also essential to ensure the normal operation of the equipment. During use, users need to check the battery status to ensure the reliable operation of the battery. To this end, it is necessary to communicate with the wireless communication module or WIFI module of the BMS through a mobile phone APP to realize functions such as remote viewing of the battery status. Therefore, throughout the life cycle of the BMS, whether it is the design stage, production stage or use stage, corresponding communication protocols and corresponding software tools are required for support and guarantee to ensure the stable performance and perfect functions of the BMS equipment, and provide users with convenient and efficient services.

[0004] The BMS (battery management system) products currently on the market generally use independent communication ports to exchange information with host computers or peripheral devices such as barcode scanners. However, the serial communication frequency between BMS and host computers or other peripheral devices is relatively low, which is mainly due to its debugging in the development stage, testing and diagnosis in the production stage, and specific needs when equipment failures are returned to the factory for repair. In the actual market application of the product, this serial communication function is often not used frequently. Therefore, from the perspective of practical application, the serial communication function of BMS products is not necessary in daily use in the market.

[0005] During the production process of PCBA finished products, the APP will not be connected during the testing phase. Wireless communication modules such as Bluetooth or WIFI and tooling tests share the same serial port channel. The presence of the wireless communication module will interfere with the communication signal of the tooling test fixture. This interference will cause communication abnormalities during the test process, which will in turn affect the accuracy of the test results. In the testing phase of the BMS finished product production and assembly process, it involves communication verification between the BMS and the tooling test fixture, as well as APP communication verification, and finally switching back to the tooling communication. In order to solve the above problems, similar products on the market usually need to set up an additional communication port specifically for communication with the tooling test fixture or the host computer. This practice not only increases production costs, but also reduces production efficiency.

[0006] As a highly integrated electronic device, BMS has complex communication requirements with other master control devices or cluster machines, so it requires more communication interfaces. However, the number of serial ports of microcontrollers of different specifications currently available on the market is fixed, which limits the expansion capability of BMS to a certain extent.

[0007] When a BMS needs to add a communication interface that is not commonly used but indispensable, we usually face a challenge: cost-effectiveness. The original MCU, which has a relatively low cost due to its small number of pins, cannot meet the needs of the new communication port. In order to solve this problem, we have to choose a MCU with more pins but a correspondingly higher cost for replacement. This replacement not only increases the manufacturing cost of the product, but may also affect its competitiveness in the market. Summary of the invention

[0008] The present invention aims to provide a single serial port automatic switching circuit, a BMS and an energy storage device to solve at least one of the above problems. The specific technical solution is as follows:

[0009] Based on the first object of the present invention, a single serial port automatic switching circuit is provided, comprising an isolated power supply module, a digital isolation chip and a connector; used for communication connection between a processor of a BMS and a wireless communication module, and switching control of communication connection between the processor and a peripheral device;

[0010] The processor is powered by a first power supply;

[0011] The isolated power supply module is used to generate a second power supply isolated from the first power supply; the second power supply is used to supply power to the wireless communication module and is output through the first terminal and the second terminal of the connector;

[0012] The digital isolation chip has a forward channel and a reverse channel; the chip side is connected to the processor of the BMS unit and is powered by the first power supply; the device side is connected to the wireless communication module and the connector and is powered by the second power supply; the data sent by the processor is forwarded through the forward channel of the digital isolation chip, sent to the wireless communication module, and sent to the peripheral device through the connector; the data sent by the wireless communication module passes through the first diode or the data sent by the peripheral device passes through the second diode, and is forwarded through the reverse channel of the digital isolation chip and sent to the processor.

[0013] Furthermore, the isolated power supply module is provided with an enable terminal, and the enable terminal is connected to the processor.

[0014] Furthermore, the isolated power supply is high level enabled, and when a high level is input to the enable terminal, the output of the isolated power supply is turned off.

[0015] Furthermore, the isolated power supply includes a four-terminal isolated DC-DC power supply module and a switching device; the switching device is connected in series between a first power ground and an input side ground pin of the isolated DC-DC power supply module, and the control end of the switching device is connected to the enable end of the isolated power supply.

[0016] Furthermore, the switch device is an N-channel field effect transistor, the source of the N-channel field effect transistor is connected to the first power ground, and the drain of the N-channel field effect transistor is connected to the input side ground pin of the isolated DC-DC module.

[0017] Furthermore, the input of the isolated DC-DC power supply module is 5V, and the output is 5V or 3.3V.

[0018] Furthermore, the model of the digital isolation chip is CA-IS3721LS.

[0019] Based on the second purpose of the present invention, a BMS unit is provided, which applies the single serial port automatic switching circuit described in any of the above technical solutions.

[0020] Based on the third object of the present invention, an energy storage device is provided, which adopts the BMS unit as described above.

[0021] The present invention has the following beneficial effects:

[0022] (1) In the PCBA finished product test, by isolating the Bluetooth serial port communication signal from the external serial port communication signal, it is ensured that when the tooling test fixture communicates with the BMS, the communication request will not be interfered by the Bluetooth signal. It can effectively improve the accuracy and efficiency of the PCBA finished product test without adding additional costs, providing a strong guarantee for the smooth progress of the production process.

[0023] (2) During the testing phase of the BMS finished product production and assembly process, when verifying APP communication, users only need to perform relevant operations directly on the APP interface without the need for additional serial port disconnection and reconnection steps. This greatly saves production time, improves production efficiency, effectively reduces labor costs, and enhances the market competitiveness of products. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is an application block diagram of the single serial port automatic switching circuit of the present invention;

[0025] Figure 2 It is a circuit diagram of the serial interface digital isolation chip of the present invention;

[0026] Figure 3 It is a circuit principle diagram of a single serial port automatic switching circuit of the present invention;

[0027] Figure 4 is a circuit diagram of an isolated power supply module of the present invention;

[0028] Figure 5 It is a circuit diagram of the single chip microcomputer and peripheral circuits of the present invention;

[0029] Figure 6 The invention discloses a circuit diagram of a power supply circuit of a single serial port automatic switching circuit. DETAILED DESCRIPTION

[0030] To further illustrate various embodiments, the present invention provides drawings. These drawings are part of the disclosure of the present invention, which 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 contents, ordinary technicians in this field should be able to understand other possible implementations and advantages of the present invention.

[0031] The present invention will now be further described with reference to the accompanying drawings and specific implementation methods.

[0032] like Figures 1 to 6 As shown, the present invention provides a single serial port automatic switching circuit 10, which is arranged between the processor 20, the serial port 30 and the wireless communication module 40 such as Bluetooth / WIFI, and is used to automatically switch the connection between the serial port of the processor 20 and the wireless communication module 40 and the peripheral device. Through the automatic switching circuit 10, the processor 20 can communicate with the APP of the smart terminal such as the mobile phone through the wireless communication method such as Bluetooth / WIFI to realize the functions such as remote viewing of the battery status; or communicate with the external serial port device (including but not limited to the test tooling, the host computer, the barcode scanning gun, etc.) through the serial port.

[0033] In this embodiment, the single serial port automatic switching circuit includes an isolated power supply module U4, a digital isolation chip U9 and a connector J2, etc. U8 is a wireless communication module, and MCU is a processor. Among them:

[0034] The isolated power module U4 is an isolated DC-DC power module with a four-pin package, an input terminal connected to a power supply of +5V, and an output terminal outputting a power supply of 3.3T (3.3V). It has the characteristics of small size, simple structure, and low cost.

[0035] The startup of the isolated power module U4 is controlled by the switch device NM12. In this embodiment, NM12 uses a MOS tube (i.e., a metal oxide semiconductor field effect tube, referred to as a field effect tube here), and NM12 is connected in series between the power ground GND and the ground pin GND of the isolated power module U4. Its gate is connected to the processor MCU through a resistor R100, and is connected to the enable signal T-EN of the power module. When the enable signal T-EN is at a high level, NM12 is turned on and U4 is started.

[0036] The digital isolation chip U9 has two channels, one forward and one reverse, to achieve bidirectional forwarding of serial port data. The digital isolation chip U9 includes a chip side and a device side. The chip side is powered by a power supply of +3.3V, and leads to the first transmit data line TX2, the first receive data line RX2 and the serial port controller of the MCU (processor 20); the device side is powered by a power supply of 3.3T, and leads to the second receive data line RX3 (reverse channel) connected to the first receive data line RX2 and the second transmit data line TX3 (forward channel) connected to the first transmit data line TX2. In this application, the digital isolation chip U9 with model CA-IS3721LS can be used. CA-IS3721LS has two channels, one forward and one reverse, and also has a fail-safe mode option. If the input power or signal is lost, the default output is low.

[0037] The second transmission data line TX3 is connected to the data receiving port TX3 (pin 9) of the wireless communication module U8 and the pin 4 of the connector JP2; the second reception data line RX3 is connected to the data transmission port RX3-1 (pin 8) of the wireless communication module U8 through the diode D18, and is connected to the pin 3 of the connector JP2 through the diode D20. The anodes of the diodes D18 and D20 are connected to the second reception data line RX3.

[0038] The above connection relationship realizes the following functions: the sending data of the MCU is forwarded through the forward channel of the digital isolation chip U9, and then sent to the wireless communication module U8, and sent to the peripheral device through the connector JP2; the sending data of the wireless communication module U8 passes through the diode D18 or the sending data of the peripheral device passes through the diode D20, and then is forwarded through the reverse channel of the digital isolation chip U9 and sent to the MCU.

[0039] Serial port 30 provides a standard RS232 interface. Connector JP2 is connected to the serial port 30 of the BMS device, and the communication with the peripheral device is connected through the serial port 30. Serial port 30 converts the serial port signal from TTL level to standard RS-232 level, and connects with the peripheral device through the serial port data line.

[0040] In this embodiment, the connector JP2 is a four-core connector, two terminals of which are connected to the power supply +3.3T and the power supply ground GT to lead out the power supply.

[0041] Figure 6 The circuit diagram of the power supply circuit of this circuit is given. The power supply circuit generates the power supply +5V, power supply +3.3D and power supply +3.3V required by this circuit. The specific output voltage can be selected according to the working voltage of the digital isolation chip U9 and the wireless communication module U8, usually +5V or 3.3V.

[0042] Working principle:

[0043] When the enable signal T-EN output by MCU 20 is at a high level, NM12 is closed, the ground pin (pin 1) of the isolation power module U4 is connected to the power ground GND, the power supply circuit is connected, and the isolation power module U4 starts working. During this process, the isolation power module U4 will perform a voltage conversion function, converting the 5V voltage to 3.3V to supply the output side of the wireless communication module U8 and the digital isolation chip U9. Once the wireless communication module U8 and the isolation chip U9 obtain a stable 3.3V voltage supply, they will be able to operate normally.

[0044] When the wireless communication module U8 and the isolation chip U9 are working normally, the processor MCU can establish a communication connection with the wireless communication module U8 or an external serial port device (including but not limited to test tooling, host computer, barcode scanner, etc.). The establishment of this communication connection enables the system to realize data transmission and interaction, thereby meeting various requirements in practical applications.

[0045] When the enable signal T-EN output by the MCU is at a low level, NM12 is disconnected, the power supply circuit of the isolated power module U4 is disconnected, and the isolated power module U4 stops working, which in turn causes the wireless communication module U8 and the digital isolation chip U9 to stop running simultaneously. This design aims to achieve precise control of the working status of the isolated power module U4 and its related components by controlling the level of the enable signal T-EN.

[0046] The BMS using the single serial port automatic switching circuit described above can realize the following applications:

[0047] 1. The Bluetooth, WIFI module or external tooling test fixture, test instrument, or host computer requests communication confirmation from the BMS:

[0048] 1) When the APP needs to connect to the BMS, Bluetooth or WIFI will issue a communication protocol request. These communication requests are in the form of a high and low level combination pulse waveform of a specific frequency, and are finally transmitted to the data receiving port RX2 (pin 13) of the MCU through the data sending port RX3-1 (pin 8) of the wireless communication module U8 through D18. After receiving the signal RX2, the MCU will determine whether the signal is a communication request. The role of D20 is to isolate the serial port of the external device to ensure that the Bluetooth communication signal is not affected by the external serial port device, while ensuring the integrity and accuracy of the Bluetooth communication request signal.

[0049] 2) When the test fixture needs to communicate with the BMS, the fixture will send a request to the BMS. Its communication protocol communicates with the MCU through D20. In this process, D18 isolates the internal Bluetooth serial port to ensure that the serial communication signal of the fixture is not affected by the internal Bluetooth serial communication signal. At the same time, this isolation also ensures the integrity and accuracy of the communication information between the BMS and the fixture.

[0050] 3) The way in which BMS automatically switches communication devices: Assume that BMS is currently communicating with APP via Bluetooth and uploading data in real time. At this time, if communication with the host computer is required, the operator can connect the communication line to the serial port, connect to JP2 through the serial port, and then select the corresponding serial port on the host computer and click to connect. Once BMS receives a communication request from the host computer, it will judge and access the serial port device according to the preset protocol, and will suspend communication with Bluetooth and automatically switch to the communication mode with the host computer. During the communication with the host computer, if APP needs to view data, the user only needs to perform the corresponding connection setting operation on APP. After receiving the online request from APP, the wireless communication module U8 of BMS will immediately send the communication protocol (i.e., communication request) to BMS. After receiving the communication request from U8, BMS will quickly interrupt the communication with the host computer, automatically switch back to the communication state with Bluetooth, upload the relevant information to Bluetooth, and Bluetooth will then forward this information to APP and display it. This flexible communication switching mechanism ensures that BMS can switch seamlessly between different devices and maintain stable and efficient communication.

[0051] The single serial port automatic switching circuit of the present invention has the following beneficial effects:

[0052] In the PCBA finished product test, by isolating the Bluetooth serial communication signal from the external serial communication signal, it is ensured that when the tooling test fixture communicates with the BMS, the communication request will not be interfered by the Bluetooth signal. This design not only ensures the normal communication process, but also ensures the authenticity and accuracy of the communication data; it can effectively improve the accuracy and efficiency of PCBA finished product testing without adding additional costs, and provide a strong guarantee for the smooth progress of the production process.

[0053] In the testing phase of the BMS finished product production and assembly process, when verifying the APP communication, the user only needs to perform relevant operations directly on the APP interface, without the need for additional serial port disconnection and reconnection steps. Although the APP shares the same serial port with the host computer, after the APP verification is completed, the system will automatically disconnect the APP connection and re-establish communication with the tooling fixture, so as to smoothly enter the next stage of testing. This design significantly simplifies the operation process and avoids the tedious steps of manual disconnection and reconnection. It not only greatly saves production hours and improves production efficiency, but also effectively reduces labor costs and enhances the market competitiveness of products. By optimizing the communication verification process, we have made positive contributions to the smooth operation of the production line and the improvement of cost-effectiveness.

[0054] like Figure 1 As shown, the present invention also provides a BMS unit, which applies the single serial port automatic switching circuit as described above, and can effectively improve the accuracy and efficiency of PCBA finished product testing without increasing additional costs; and significantly simplify the operating process in the testing link of the BMS finished product production and assembly process, avoiding the tedious steps of manual disconnection and reconnection.

[0055] like Figure 1 As shown, the present invention also provides an energy storage device, which adopts the BMS unit as described above, so as to have the above-mentioned beneficial effects.

[0056] Although the present invention has been specifically shown and described in conjunction with the preferred embodiments, it should be understood by those skilled in the art that various changes may be made to the present invention in form and details without departing from the spirit and scope of the present invention as defined by the appended claims, all of which are within the scope of protection of the present invention.

Claims

1. A single serial port automatic switching circuit, characterized in that: It includes an isolated power supply module, a digital isolation chip and a connector; it is used for the communication connection between the processor of the BMS and the wireless communication module, and the switching control of the communication connection between the processor and the peripherals; The processor is powered by a first power supply; The isolated power supply module is used to generate a second power supply isolated from the first power supply; the second power supply is used to supply power to the wireless communication module and is output through the first terminal and the second terminal of the connector; The digital isolation chip has a forward channel and a reverse channel; The chip side is connected to the processor of the BMS unit and is powered by the first power supply; the device side is connected to the wireless communication module and the connector and is powered by the second power supply; the data sent by the processor is forwarded through the forward channel of the digital isolation chip, and then sent to the wireless communication module, and sent to the peripheral device through the connector; the data sent by the wireless communication module passes through the first diode or the data sent by the peripheral device passes through the second diode, and then is forwarded through the reverse channel of the digital isolation chip and sent to the processor.

2. The single serial port automatic switching circuit according to claim 1, characterized in that: The isolated power supply module is provided with an enable terminal, and the enable terminal is connected to the processor.

3. The single serial port automatic switching circuit as claimed in claim 2, characterized in that: The isolated power supply is enabled at a high level. When a high level is input to the enable terminal, the output of the isolated power supply is turned off.

4. The single serial port automatic switching circuit as claimed in claim 3, characterized in that: The isolated power supply includes a four-terminal isolated DC-DC power supply module and a switching device; the main circuit of the switching device is connected in series between the first power ground and the input side ground pin of the isolated DC-DC power supply module, and the control end of the switching device is connected to the enable end of the isolated power supply.

5. The single serial port automatic switching circuit as claimed in claim 4, characterized in that: The switch device is an N-channel field effect transistor, a source of the N-channel field effect transistor is connected to the first power ground, and a drain of the N-channel field effect transistor is connected to the input side ground pin of the isolated DC-DC power module.

6. The single serial port automatic switching circuit according to claim 1, characterized in that: The input of the isolated DC-DC power supply module is 5V, and the output is 5V or 3.3V.

7. The single serial port automatic switching circuit according to claim 1, characterized in that: The model of the digital isolation chip is CA-IS3721LS.

8. A BMS unit, characterized in that: The single serial port automatic switching circuit as described in any one of claims 1 to 7 is applied.

9. An energy storage device, characterized in that: A BMS unit as claimed in claim 8 is used.

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