Battery module electrical position automatic identification system and method based on serial communication

Abstract

The present invention relates to a battery module electrical position automatic identification system based on serial communication, including a power battery management system; the power battery management system includes a master control BCU and a slave control BMU; the present invention also relates to a battery module electrical position automatic identification method based on serial communication, including the steps of: starting a low-voltage power-on process; a module electrical position automatic identification process; an electrical position automatic identification fault judgment process. The present invention does not need to set the module number in advance, and automatically locates the module location; reduces the cost of module numbering, and improves the system assembly efficiency; prevents the battery management system from being unable to identify when multiple models of battery packs or battery modules are assembled and the battery packs or battery modules are misassembled; prevents the branch voltage inconsistency caused by misassembly during battery system assembly, resulting in large current shock and thermal runaway.

Description

Technical Field

[0001] The present invention relates to the field of new energy vehicle battery management systems, and in particular to a battery module electrical position automatic identification system and method based on serial communication. Background Art

[0002] The power battery system for new energy commercial vehicles has a large amount of power and a large number of battery cells, so the power batteries cannot be arranged in a centralized and unified manner. Therefore, the battery system for new energy commercial vehicles is composed of multiple battery packs or battery modules. When one or more battery cells in the power battery system fail, the power battery management system is required to make an accurate judgment in order to identify the location of the failed cell.

[0003] In order to achieve the above technical goals, the current existing technology adopts the technical means of manually numbering each battery pack or battery module, and calibrating and storing the battery cell number in the slave control unit. Therefore, when assembling the power battery system, it must be assembled according to the number.

[0004] The defects of the prior art are as follows:

[0005] 1. According to the technical solutions of the prior art, it is necessary to manually number the power battery pack or battery module, which requires the power battery system to be assembled according to the number, which will reduce the system assembly efficiency and increase the cost of manual numbering;

[0006] 2. Once the power battery system is not assembled according to the number, it will lead to the inability to accurately locate the faulty battery cell when identifying it;

[0007] 3. Further, if the battery system has multiple models of battery packs or battery modules, once the power battery system is not assembled according to the number, the battery management system cannot identify it, which will lead to inconsistent branch voltages;

[0008] 4. Finally, when assembling the battery system, large current shocks may occur due to inconsistent branch voltages, causing battery damage and even the risk of thermal runaway, endangering personal safety and causing property losses. Summary of the invention

[0009] In view of the above problems, the present invention provides a battery module electrical position automatic identification system and method based on serial communication, the purpose of which is to achieve automatic positioning of the module without setting the module number in advance; reduce the cost of module numbering and improve the system assembly efficiency; eliminate the problem that when multiple models of battery packs or battery modules are assembled, once the power battery system is not assembled according to the number, the battery management system cannot identify it, resulting in inconsistent branch voltages; eliminate the problem that when assembling the battery system, large current shocks due to inconsistent branch voltages cause battery damage, and may even lead to the risk of thermal runaway, endangering personal safety, and causing the possibility of property loss.

[0010] To solve the above problems, the technical solution provided by the present invention is:

[0011] A battery module electrical position automatic identification system based on serial communication, comprising a power battery management system; the power battery management system is a master-slave architecture, comprising a master control BCU and several slave control BMUs; wherein:

[0012] The main control BCU is used to control, manage, detect and calculate the electric and thermal parameters of the battery system; the electric and thermal parameters include single cell voltage, single cell temperature, system high voltage, system current, coolant temperature, charging station temperature and ambient temperature; the main control BCU is also used to realize the communication between the battery system and other on-board controllers and non-on-board controllers;

[0013] The slave BMU is used to collect voltage signals and temperature signals of battery cells, and process the voltage signals and temperature signals of the battery cells and send them to the master BCU through the internal CAN bus; the slave BMU is also used to implement the battery balancing function;

[0014] Each battery module uniquely matches one slave control BMU.

[0015] Preferably, the master control BCU includes an identification output hard-wire interface and an identification input hard-wire interface.

[0016] Preferably, the slave control BMU includes an identification output hard-line interface and an identification input hard-line interface.

[0017] Preferably, the identification output hardwire interface of the master control BCU is electrically signal coupled to the identification input hardwire interface of the slave control BMU ranked first in electrical position;

[0018] The identification output hard-wire interface of the slave control BMU at the end of the electrical position row is electrically signal-coupled with the identification input hard-wire interface of the master control BCU;

[0019] The identification output hard-wire interfaces of all the slave-controlled BMUs are electrically signal-coupled with the identification input hard-wire interfaces of the slave-controlled BMUs that are one position later than the own electrical appliance to form a series loop.

[0020] A method for automatically identifying the electrical position of a battery module based on serial communication, which utilizes the above-mentioned battery module electrical position automatic identification system based on serial communication, comprises the following steps:

[0021] S100. Start the low-voltage power-on process until the master BCU and the slave BMU are powered on; S200. Execute the module electrical position automatic identification process;

[0022] S300. Execute the electrical position automatic identification fault judgment process.

[0023] Preferably, the module electrical position identification process specifically includes the following steps:

[0024] S210. The master BCU sends an identification electrical signal numbered Sig01 through its own identification output hardwire interface to the identification input hardwire interface of the slave BMU whose electrical position is the first;

[0025] S220. After the identification input hard-wire interface of the slave control BMU ranked first in electrical position receives the identification electrical signal numbered Sig01, it automatically sets the ID of the CAN communication message to 01, and then sends out the CAN communication message; the slave control BMU ranked first in electrical position simultaneously sends the identification electrical signal numbered Sig02 to the identification output hard-wire interface of the slave control BMU coupled with the electrical signal through its own identification output hard-wire interface;

[0026] S230. After receiving the identification electrical signal, the identification input hard-wire interface of each slave control BMU automatically adds 1 to the ID of the CAN communication message, assigns the ID of the CAN communication message, and then sends out the CAN communication message; at the same time, each slave control BMU simultaneously sends the identification electrical signal with a number starting with Sig and a value of 1 greater than its own electrical position to the identification output hard-wire interface of the slave control BMU coupled with the electrical signal through its own identification output hard-wire interface;

[0027] S240. Repeat S230 until the slave BMU with the last electrical position sends the CAN communication message, and at the same time sends the identification electrical signal with a number starting with Sig and a value of 1 greater than its own electrical position to the identification output hard-wire interface of the master BCU coupled with the electrical signal through its own identification output hard-wire interface;

[0028] S250. After receiving the identification electrical signal numbered Sig and having a value greater than its own electrical position plus 1, the master control BCU counts the number of the CAN communication messages and the identification electrical signal;

[0029] S260. Determine whether the number of modules is correct based on the number of CAN communication messages and the identification signal with a number starting with Sig and a value greater than its own electrical position plus 1, sent by the slave control BMU with the last electrical position; and then perform the following operations based on the judgment result:

[0030] If the module quantity is correct, execute S270;

[0031] If the module quantity is incorrect, a module quantity error fault alarm is reported;

[0032] S270. Determine whether the module electrical position is correct based on the number of CAN communication messages and the identification electrical signal numbered Sig and having a value greater than its own electrical position plus 1, sent by the slave control BMU with the last electrical position; and then perform the following operations based on the judgment result:

[0033] If the module electrical position is correct, the module electrical position identification process ends;

[0034] If the module quantity is incorrect, a module electrical position error fault alarm is reported.

[0035] Preferably, the electrical position automatic identification fault judgment process specifically includes the following steps:

[0036] S310. Execute the module quantity error fault judgment sub-process;

[0037] S320. Execute the module assembly error fault judgment sub-process.

[0038] Preferably, the module quantity error fault judgment sub-process specifically includes the following steps:

[0039] S311. After receiving the identification electrical signal numbered Sig and having a value greater than its own electrical position plus 1, the master control BCU calculates the actual number of modules based on the identification electrical signal;

[0040] S312. Compare the calculated actual number of modules with the number of modules recorded in the BCU system configuration information; then perform the following operations based on the comparison result:

[0041] If the comparison result is that the actual number of modules is consistent with the number of modules recorded in the BCU system configuration information, then the module number error fault judgment sub-process is terminated;

[0042] If the comparison result is that the actual module quantity is inconsistent with the module quantity recorded in the BCU system configuration information, a module quantity error fault alarm is reported.

[0043] Preferably, the module assembly error fault judgment sub-process specifically includes the following steps:

[0044] S321. The master control BCU sequentially reads the module configuration information in the CAN communication message sent by each slave control BMU; the module configuration information includes electrical energy, capacity, and module grouping mode;

[0045] S322. The master control BCU sequentially compares the module configuration information in the CAN communication message sent by each slave control BMU with the module configuration information of the corresponding electrical position recorded in the BCU system configuration information; and then performs the following operations according to the comparison result:

[0046] If the comparison result is that the module configuration information in the CAN communication message sent by the current slave BMU is consistent with the module configuration information of the corresponding electrical position recorded in the BCU system configuration information, then the module assembly error fault judgment sub-process is terminated;

[0047] If the comparison result is that the module configuration information in the CAN communication message sent by the current slave control BMU is inconsistent with the module configuration information of the corresponding electrical position recorded in the BCU system configuration information, a module assembly error fault alarm is reported.

[0048] Preferably, the identification electrical signal adopts a PWM signal and is sent in sequence from small to large according to the duty cycle; or the identification electrical signal adopts a digital signal and is sent in sequence from small to large in a serial communication mode.

[0049] Compared with the prior art, the present invention has the following advantages:

[0050] 1. Since the present invention provides a method for automatically identifying the electrical position of a module that has not been used in the current prior art, it is possible to automatically locate the location of the module without setting the module number in advance;

[0051] 2. Since the method of the present invention can automatically locate the location of the module, the cost of module numbering is reduced and the system assembly efficiency is improved;

[0052] 3. Since the present invention also provides an automatic fault identification process, it eliminates the problem that when multiple models of battery packs or battery modules are assembled, once the power battery system is not assembled according to the number, the battery management system cannot identify it, resulting in inconsistent branch voltages;

[0053] 4. Since the present invention also provides an automatic fault identification and judgment process, it eliminates the possibility of large current shocks due to inconsistent branch voltages during battery system assembly, resulting in battery damage and even the risk of thermal runaway, endangering personal safety and causing property losses. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Figure 1 A schematic diagram of the wiring principle of the module electrical position identification of a specific embodiment of the present invention;

[0055] Figure 2 It is a schematic diagram of the module electrical position identification control logic flow of a specific embodiment of the present invention. DETAILED DESCRIPTION

[0056] The present invention is further explained below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention. After reading the present invention, various equivalent forms of modifications to the present invention by those skilled in the art all fall within the scope defined by the claims attached to this application.

[0057] It should be explained in advance that the purpose of the automatic identification system and method for the electrical position of a battery pack or battery module proposed in the present invention is to automatically realize the electrical position numbering and identification of the battery module. For a power battery system with multiple battery pack models or multiple battery module models, if different models of battery packs or battery modules are misinstalled, fault diagnosis and alarm can also be performed.

[0058] like Figure 1 As shown, a battery module electrical position automatic identification system based on serial communication includes a power battery management system; the power battery management system is a master-slave architecture, including a master control BCU and several slave control BMUs; wherein:

[0059] The main control BCU is used to control, manage, detect and calculate the electric and thermal related parameters of the battery system; the electric and thermal related parameters include single cell voltage, single cell temperature, system high voltage, system current, coolant temperature, charging station temperature and ambient temperature; the main control BCU is also used to realize the communication between the battery system and other on-board controllers and non-on-board controllers.

[0060] In this specific embodiment, the master BCU includes an identification output hard-line interface and an identification input hard-line interface.

[0061] The slave BMU is used to collect the voltage and temperature signals of the battery cells, and after processing, send the voltage and temperature signals of the battery cells to the master BCU through the internal CAN bus; the slave BMU is also used to implement the battery balancing function.

[0062] Each battery module is uniquely matched with one slave control BMU.

[0063] In this specific embodiment, the slave control BMU includes an identification output hard-line interface and an identification input hard-line interface.

[0064] In this specific embodiment, the identification output hard-wire interface of the master BCU is electrically signal-coupled to the identification input hard-wire interface of the slave BMU that ranks first in electrical position.

[0065] The identification output hard-wire interface of the last slave BMU in the electrical position row is electrically signal coupled to the identification input hard-wire interface of the master BCU.

[0066] The identification output hard-wire interfaces of all slave-controlled BMUs are electrically signal-coupled with the identification input hard-wire interfaces of the slave-controlled BMUs that are one position later than their own electrical appliances, forming a series loop.

[0067] It should be noted that the connection method in this specific embodiment is: the identification output hard-wire interface of the master BCU is connected to the identification input hard-wire interface of the slave BMU1 with an electrical position of 1, the identification input hard-wire interface of the slave BMU1 is connected to the identification input hard-wire interface of the slave BMU2 with an electrical position of 2, and the other slave BMUs are connected in series in sequence until the identification output hard-wire interface of the last slave BMU is connected to the identification input hard-wire interface of the master BCU, forming a series loop.

[0068] like Figure 2 As shown, a method for automatically identifying the electrical position of a battery module based on serial communication using the above-mentioned battery module electrical position automatic identification system based on serial communication comprises the following steps:

[0069] S100. After the power battery system is connected, start the low-voltage power-on process until the master control BCU and the slave control BMU are powered on; after the BCU and BMU are powered on, start the module electrical position identification.

[0070] S200. Execute the module electrical position automatic identification process.

[0071] In this specific embodiment, the module electrical position identification process specifically includes the following steps:

[0072] S210. The master BCU sends an identification electrical signal numbered Sig01 to the identification input hard-wire interface of the slave BMU ranked first in electrical position through its own identification output hard-wire interface.

[0073] S220. After the identification input hard-wire interface of the slave control BMU ranked first in electrical position receives the identification electrical signal numbered Sig01, it automatically sets the ID of the CAN communication message to 01, and then sends out the CAN communication message; at the same time, the slave control BMU ranked first in electrical position sends the identification electrical signal numbered Sig02 to the identification output hard-wire interface of the slave control BMU coupled with the electrical signal through its own identification output hard-wire interface.

[0074] S230. After the identification input hard-wire interface of each slave-control BMU identifies the electrical signal, it automatically adds 1 to the ID of the CAN communication message, assigns the ID of the CAN communication message, and then sends out the CAN communication message; at the same time, each slave-control BMU sends an identification electrical signal with a number starting with Sig and a value of 1 greater than its own electrical position through its own identification output hard-wire interface to the identification output hard-wire interface of the slave-control BMU coupled to the electrical signal.

[0075] S240. Repeat S230 until the last slave BMU in the electrical position row sends a CAN communication message, and at the same time sends an identification electrical signal with a number starting with Sig and a value that is 1 greater than its own electrical position to the identification output hard-wire interface of the master BCU coupled to the electrical signal through its own identification output hard-wire interface.

[0076] S250. After receiving the identification electrical signal numbered Sig and having a value of 1 greater than its own electrical position, sent by the last slave BMU in the electrical position row, the master BCU counts the number of CAN communication messages and the identification electrical signal.

[0077] S260. Determine whether the number of modules is correct based on the number of CAN communication messages and the identification signal sent by the slave BMU with the last electrical position and the number starting with Sig and the value of which is 1 more than its own electrical position; then perform the following operations based on the judgment result:

[0078] If the number of modules is correct, execute S270.

[0079] If the module quantity is incorrect, a module quantity error fault alarm is reported.

[0080] S270. Determine whether the module electrical position is correct based on the number of CAN communication messages and the identification signal sent by the slave BMU with the last electrical position and number starting with Sig and with a value of 1 greater than its own electrical position; then perform the following operations based on the judgment result:

[0081] If the module electrical position is correct, the module electrical position identification process ends.

[0082] If the module quantity is incorrect, a module electrical position error fault alarm is reported.

[0083] It should be noted that, in this specific embodiment, the control process principle of S200 is as follows:

[0084] First, the master BCU sends an identification signal Sig01 through the electrical position identification output port. After receiving the identification signal Sig01 sent by the BCU, the slave BMU1 with an electrical position of 1 automatically sets the CAN communication message ID to 01, sends out a CAN communication message, and sends an identification signal Sig02 through the electrical position identification output port. After receiving the identification signal Sig02 sent by the BCU, the slave BMU2 with an electrical position of 2 automatically sets the CAN communication message ID to 02, sends out a CAN communication message, and sends an identification signal Sig03 through the electrical position identification output port. Subsequent slave BMUs follow the above process and automatically set the CAN communication message ID after receiving the identification signal of the previous slave BMU, and send identification signals through the electrical position identification output port, until the master BCU receives the identification signal Sig(n+1) sent by the last slave BMUn. After receiving the identification signal Sig(n+1) sent by the last slave BMUn, the BCU determines whether the number of modules is correct and whether the module electrical position is incorrect based on the number of slave BMU message IDs and the identification signal Sig(n+1). If the number of modules is correct and the module electrical position is correct, the module identification ends; if an error occurs, the fault is reported.

[0085] S300. Execute the electrical position automatic identification fault judgment process.

[0086] In this specific embodiment, the electrical position automatic identification fault judgment process specifically includes the following steps:

[0087] S310. Execute the module quantity error fault judgment sub-process.

[0088] In this specific embodiment, the module quantity error fault judgment sub-process specifically includes the following steps:

[0089] S311. After receiving an identification electrical signal numbered Sig and having a value greater than its own electrical position plus 1, the master BCU calculates the actual number of modules based on the identification electrical signal.

[0090] S312. Compare the calculated actual number of modules with the number of modules recorded in the BCU system configuration information; then perform the following operations based on the comparison result:

[0091] If the comparison result is that the actual module quantity is consistent with the module quantity recorded in the BCU system configuration information, the module quantity error fault judgment sub-process is terminated.

[0092] If the comparison result is that the actual module quantity is inconsistent with the module quantity recorded in the BCU system configuration information, a module quantity error fault alarm is reported.

[0093] It should be noted that, in this specific embodiment, the control process principle of the module quantity error fault judgment sub-process is as follows:

[0094] After the master control BCU receives the identification electrical signal Sig(n+1) sent by the last slave control BMUn, it calculates the actual number of modules according to the signal Sig(n+1). The actual number of modules calculated by the module identification electrical signal received by the BCU is compared with the number of modules recorded in the BCU system configuration information. If they are inconsistent, the module number error fault is reported.

[0095] S320. Execute the module assembly error fault judgment sub-process.

[0096] In this specific embodiment, the module assembly error fault judgment sub-process specifically includes the following steps:

[0097] S321. The master control BCU reads the module configuration information in the CAN communication message sent by each slave control BMU in turn; the module configuration information includes electrical energy, capacity, and module grouping method.

[0098] S322. The master control BCU sequentially compares the module configuration information in the CAN communication message sent by each slave control BMU with the module configuration information of the corresponding electrical position recorded in the BCU system configuration information; and then performs the following operations according to the comparison results:

[0099] If the comparison result is that the module configuration information in the CAN communication message sent by the current slave control BMU is consistent with the module configuration information of the corresponding electrical position recorded in the BCU system configuration information, the module assembly error fault judgment sub-process is terminated.

[0100] If the comparison result is that the module configuration information in the CAN communication message sent by the current slave control BMU is inconsistent with the module configuration information of the corresponding electrical position recorded in the BCU system configuration information, a module assembly error fault alarm is reported.

[0101] At this point, the problem that the existing technology manually numbers the power battery pack or battery module, and requires the power battery system to be assembled according to the numbering, is fundamentally solved; based on this, the system assembly efficiency will not be reduced, and the cost of manual numbering is also reduced.

[0102] On the other hand, by adopting the above-mentioned technical scheme, once the power battery system is not assembled according to the number, it will not lead to the inability to accurately identify the faulty battery cell when identifying, because the present invention adopts automatic and accurate positioning technology; if the battery system has multiple models of battery packs or battery modules, once the power battery system is not assembled according to the number, the battery management system can identify them to avoid inconsistent branch voltages; further, when assembling the battery system, there will be no large current shock caused by inconsistent branch voltages, resulting in battery damage, and even the risk of thermal runaway, which will not endanger personal safety or cause property loss.

[0103] In this specific embodiment, the identification electrical signal adopts a PWM signal and is sent in sequence from small to large according to the duty cycle.

[0104] For example: duty cycle 2%, 4%, 6%, ... 100%, the identification signal sent by the BCU through the electrical position identification output port is a PWM signal with a duty cycle of 2%, the identification signal sent by the slave control BMU1 with an electrical position of 1 through the electrical position identification output port is a PWM signal with a duty cycle of 4%, the identification signal sent by the slave control BMU2 with an electrical position of 2 through the electrical position identification output port is a PWM signal with a duty cycle of 6%, and so on. If the identification signal sent by the last module through the electrical position identification output port is a PWM signal with a duty cycle of n%, the number of modules should be (n / 2-1).

[0105] In this specific embodiment, the identification electrical signal may also be a digital signal, and is sent in sequence from small to large in a serial communication manner.

[0106] For example: 8-bit digital signals 0, 5, 10, ... 250, the identification signal sent by the BCU through the electrical position identification output port is a digital signal of 0, the identification signal sent by the slave control BMU1 with an electrical position of 1 through the electrical position identification output port is a digital signal of 5, the identification signal sent by the slave control BMU2 with an electrical position of 2 through the electrical position identification output port is a digital signal of 10, and so on. If the identification signal sent by the last module through the electrical position identification output port is a PWM signal of n, the number of modules should be n / 5.

[0107] In the above detailed description, various features are grouped together in a single embodiment to simplify the disclosure. This method of disclosure should not be interpreted as reflecting an intention that the embodiments of the claimed subject matter require more features than are clearly stated in each claim. On the contrary, as reflected in the appended claims, the invention is in a state of having less than all the features of the disclosed individual embodiments. Therefore, the appended claims are hereby expressly incorporated into the detailed description, with each claim standing on its own as a separate preferred embodiment of the invention.

[0108] The disclosed embodiments are described above to enable any person skilled in the art to implement or use the present invention. Various modifications of these embodiments are obvious to those skilled in the art, and the general principles defined herein may also be applied to other embodiments without departing from the spirit and scope of the present disclosure. Therefore, the present disclosure is not limited to the embodiments given herein, but is consistent with the broadest scope of the principles and novel features disclosed in this application.

[0109] The above description includes examples of one or more embodiments. Of course, it is not possible to describe all possible combinations of components or methods for the purpose of describing the above embodiments, but it should be recognized by those skilled in the art that the various embodiments may be further combined and arranged. Therefore, the embodiments described herein are intended to cover all such changes, modifications and variations that fall within the scope of protection of the appended claims. In addition, with respect to the term "comprising" used in the specification or claims, the word is covered in a manner similar to the term "including", just as "including," is explained as a transitional word in the claims. In addition, any term "or" used in the specification of the claims is intended to mean "non-exclusive or".

[0110] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A battery module electrical position automatic identification system based on serial communication, characterized in that: It includes a power battery management system; the power battery management system is a master-slave architecture, including a master control BCU and several slave control BMUs; wherein: The main control BCU is used to control, manage, detect and calculate the electric and thermal parameters of the battery system; the electric and thermal parameters include single cell voltage, single cell temperature, system voltage, system current, coolant temperature, charging station temperature and ambient temperature; the main control BCU is also used to realize the communication between the battery system and other on-board controllers and non-on-board controllers; The slave BMU is used to collect voltage signals and temperature signals of battery cells, and process the voltage signals and temperature signals of the battery cells and send them to the master BCU through the internal CAN bus; the slave BMU is also used to implement the battery balancing function; Each battery module uniquely matches one slave control BMU; The master control BCU includes an identification output hard-wire interface and an identification input hard-wire interface; The slave control BMU includes an identification output hard-wire interface and an identification input hard-wire interface; The identification output hard-wire interface of all the slave control BMUs is electrically coupled to the identification input hard-wire interface of the slave control BMU that is one position behind the own electrical appliance to form a series loop; the specific connection method is: The identification output hardwire interface of the master BCU is connected to the identification input hardwire interface of the slave BMU1 whose electrical position is 1, the identification input hardwire interface of the slave BMU1 is connected to the identification input hardwire interface of the slave BMU2 whose electrical position is 2, and the other slave BMUs are connected in series in sequence until the identification output hardwire interface of the last slave BMU is connected to the identification input hardwire interface of the master BCU, forming a series loop.

2. A method for automatically identifying the electrical position of a battery module based on serial communication using the battery module electrical position automatic identification system based on serial communication according to claim 1, characterized in that: The following steps are involved: S100. Start the low-voltage power-on process until the master BCU and the slave BMU are powered on; S200. Execute the module electrical position automatic identification process; S300. Execute the electrical position automatic identification fault judgment process; The module electrical position identification process specifically includes the following steps: S210. The master BCU sends an identification electrical signal numbered Sig01 through its own identification output hardwire interface to the identification input hardwire interface of the slave BMU whose electrical position is the first; S220. After the identification input hard-wire interface of the slave control BMU ranked first in electrical position receives the identification electrical signal numbered Sig01, it automatically sets the ID of the CAN communication message to 01, and then sends out the CAN communication message; the slave control BMU ranked first in electrical position simultaneously sends the identification electrical signal numbered Sig02 to the identification output hard-wire interface of the slave control BMU coupled with the electrical signal through its own identification output hard-wire interface; S230. After receiving the identification electrical signal, the identification input hard-wire interface of each slave control BMU automatically adds 1 to the ID of the CAN communication message, assigns the ID of the CAN communication message, and then sends out the CAN communication message; at the same time, each slave control BMU simultaneously sends the identification electrical signal with a number starting with Sig and a value of 1 greater than its own electrical position to the identification output hard-wire interface of the slave control BMU coupled with the electrical signal through its own identification output hard-wire interface; S240. Repeat S230 until the slave BMU at the end of the electrical position sends the CAN communication message, and at the same time sends the identification electrical signal with a number starting with Sig and a value of 1 greater than its own electrical position to the identification input hard-wire interface of the master BCU coupled to the electrical signal through its own identification output hard-wire interface; S250. After receiving the identification electrical signal numbered Sig and having a value greater than its own electrical position plus 1, the master control BCU counts the number of the CAN communication messages and the identification electrical signal; S250. Determine whether the number of modules is correct based on the number of CAN communication messages and the identification signal with a number starting with Sig and a value greater than its own electrical position plus 1, sent by the slave control BMU with the last electrical position; and then perform the following operations based on the judgment result: If the module quantity is correct, execute S260; If the module quantity is incorrect, a module quantity error fault alarm is reported; S260. Determine whether the module electrical position is correct based on the number of CAN communication messages and the identification electrical signal numbered Sig and having a value greater than its own electrical position plus 1, sent by the slave control BMU with the last electrical position; and then perform the following operations based on the judgment result: If the module electrical position is correct, the module electrical position identification process ends; If the module quantity is incorrect, a module electrical position error fault alarm is reported.

3. The method for automatically identifying the electrical position of a battery module based on serial communication according to claim 2, characterized in that: The electrical position automatic identification fault judgment process specifically includes the following steps: S310. Execute the module quantity error fault judgment sub-process; S320. Execute the module assembly error fault judgment sub-process.

4. The method for automatically identifying the electrical position of a battery module based on serial communication according to claim 3, characterized in that: The module quantity error fault judgment sub-process specifically includes the following steps: S311. After receiving the identification electrical signal numbered Sig and having a value greater than its own electrical position plus 1, the master control BCU calculates the actual number of modules based on the identification electrical signal; S312. Compare the calculated actual number of modules with the number of modules recorded in the BCU system configuration information; then perform the following operations based on the comparison result: If the comparison result is that the actual number of modules is consistent with the number of modules recorded in the BCU system configuration information, then the module number error fault judgment sub-process is terminated; If the comparison result is that the actual module quantity is inconsistent with the module quantity recorded in the BCU system configuration information, a module quantity error fault alarm is reported.

5. The method for automatically identifying the electrical position of a battery module based on serial communication according to claim 4, characterized in that: The module assembly error fault judgment sub-process specifically includes the following steps: S321. The master control BCU sequentially reads the module configuration information in the CAN communication message sent by each slave control BMU; the module configuration information includes electrical energy and capacity; S322. The master control BCU sequentially compares the module configuration information in the CAN communication message sent by each slave control BMU with the module configuration information of the corresponding electrical position recorded in the BCU system configuration information; and then performs the following operations according to the comparison result: If the comparison result is that the module configuration information in the CAN communication message sent by the current slave BMU is consistent with the module configuration information of the corresponding electrical position recorded in the BCU system configuration information, then the module assembly error fault judgment sub-process is terminated; If the comparison result is that the module configuration information in the CAN communication message sent by the current slave control BMU is inconsistent with the module configuration information of the corresponding electrical position recorded in the BCU system configuration information, a module assembly error fault alarm is reported.

6. The method for automatically identifying the electrical position of a battery module based on serial communication according to claim 5, characterized in that: The identification electrical signal adopts a PWM signal and is sent in sequence from small to large according to the duty cycle; or the identification electrical signal adopts a digital signal and is sent in sequence from small to large in a serial communication mode.

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