A system and method for high voltage lithium battery control for a civil aircraft

Abstract

A high voltage lithium battery control system for a civil aircraft includes a plurality of battery modules connected in series to form a series loop, each battery module including a plurality of lithium batteries; slave BMS controllers configured to collect module information within the battery modules; and module internal switches BSCs configured to be driven by the slave BMS controllers to enable and disable the battery modules from the series loop; a high voltage control module including bypass switches configured to perform bypass control on respective ones of the plurality of battery modules; a master BMS controller configured to: receive the module information sent from each of the slave BMS controllers; calculate battery system status information based on the module information and report it to a high voltage DC bus power controller BPCU; and control the module internal switches BSCs and the bypass switches based on information received from the BPCU and the module information. A method for a high voltage lithium battery control system for a civil aircraft is also provided.

Description

Technical Field

[0001] This invention relates to the fields of battery power supply technology and high-voltage battery control technology for civil aircraft, and in particular to a system and method for controlling high-voltage lithium batteries for civil aircraft. Background Technology

[0002] Currently, there is a lack of system architecture and control methods for using high-voltage lithium batteries as emergency power sources for civil aircraft. To meet airworthiness requirements, there are still many problems to be solved in constructing high-voltage DC systems using lithium batteries.

[0003] First, existing patents in the new energy field mainly consider the handling of battery faults such as overcurrent, overcharge / overdischarge from the power battery system level. The method is to disconnect the main contactor between the battery pack and the high-voltage bus to isolate the battery pack from the external load. However, they do not consider the isolation of internal system faults and the degraded use of the system under fault modes. This is not suitable for the working scenario of emergency batteries and does not meet the requirements of airworthiness regulations regarding the impact of system faults.

[0004] Secondly, current power battery systems are basically centrally located. Although there are modular architecture designs, they tend to prioritize the modular division of the Battery Management System (BMS) monitoring functions. Certification experience with existing civil aviation products shows that centrally located high-voltage lithium batteries are highly susceptible to thermal runaway, potentially leading to violent explosions and catastrophic consequences for flight safety, failing to meet the explosion safety requirements of regulations and standards.

[0005] In summary, to meet the high safety and high availability requirements of civil aircraft power systems, it is urgent to design a flexible and reconfigurable high-voltage lithium battery system and its control method. Summary of the Invention

[0006] This summary is provided to introduce, in a simplified form, some concepts that will be further described in the following detailed description. This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to help determine the scope of the claimed subject matter.

[0007] The present invention aims to provide a high-voltage lithium battery control system and method for use in civil aircraft.

[0008] According to one aspect of the present invention, a high-voltage lithium battery control system for a civil aircraft is provided. The control system may include: a plurality of battery modules connected in series to form a series circuit, each battery module including: a plurality of lithium batteries; a slave battery management system (BMS) controller configured to acquire module information within the battery module; and a battery series contactor (BSC) internal to the module configured to be driven by the slave BMS controller to achieve switching of the battery module with the series circuit; a high-voltage control module including: a bypass switch configured to perform bypass control on a corresponding module among the plurality of battery modules; a master battery management system (BMS) controller configured to: receive module information sent from each slave BMS controller; calculate battery system status information based on the module information and report it to a high-voltage DC busbar power controller (BPCU); and control the module internal switch (BSC) and the bypass switch based on information received from the BPCU and the module information.

[0009] According to one embodiment of the present invention, the module information may include one or more of the following: module state of charge (SoC), state of power (SoP), fault mode, and alarm information, wherein the fault mode includes one of the following: open circuit fault, overcharge fault, over-discharge fault, or thermal runaway fault, and wherein the alarm information includes an abnormal temperature rise alarm.

[0010] According to one embodiment of the present invention, the battery system status information may include one or more of the following: system state of charge (SoC), system power state (SoP), number of working modules, system fault alarm, and maximum allowable discharge time under the current load. The information received from the BPCU includes mode commands and external load requirements. The mode commands include one of normal power supply and allowable power balancing. The external load requirements include one or more of power, voltage, and task time.

[0011] According to one embodiment of the present invention, the bypass switch may include a first main bypass contactor MBPC and a second bypass contactor BPC, wherein when the first main bypass contactor MBPC and the second bypass contactor BPC are to be closed, the first switch MBPC closes later than the second switch BPC to control the influence of the electric arc, and there is a logical interlock between the bypass switch and the module internal switch BSC, wherein the corresponding bypass switch can only be closed after it is confirmed that the module internal switch BSC is open.

[0012] According to one embodiment of the present invention, each battery module may be provided with a separate exhaust channel for thermal runaway pressure relief and exhaust.

[0013] According to another aspect of the present invention, a method for a high-voltage lithium battery control system for a civil aircraft is provided. The high-voltage lithium battery control system may include: a plurality of battery modules connected in series to form a series circuit, each battery module including: a plurality of lithium batteries; a slave battery management system (BMS) controller; and a battery series contactor (BSC) inside the module; a high-voltage control module including: a bypass switch; and a main battery management system (BMS) controller; the method may include the following steps: the slave BMS controller acquires module information within the corresponding battery module; the main BMS controller receives the module information acquired by each slave BMS controller; the main BMS controller calculates battery system status information based on the module information and reports it to a high-voltage DC busbar power controller (BPCU); and the main BMS controller controls the module internal switch (BSC) and the bypass switch based on the information received from the BPCU and the module information.

[0014] According to one embodiment of the present invention, the method may include: in normal operating mode, when the master BMS controller receives a normal power supply command sent by the BPCU, the master BMS controller sends a module internal switch BSC closing command to the slave BMS controller, the slave BMS controller closes the module internal switch BSC, and the bypass switch remains open.

[0015] According to one embodiment of the present invention, the method may include: in a single module failure mode, when the slave BMS controller detects a module failure, performing a bypass to the faulty module, wherein performing the bypass to the faulty module includes: the slave BMS controller disconnecting the module internal switch BSC and sending the fault information of the faulty module and the disconnection status of the module internal switch BSC to the master BMS controller, and the master BMS controller controlling the closing of the bypass switch corresponding to the faulty module based on the disconnection status of the module internal switch BSC.

[0016] According to one embodiment of the present invention, the method may include: in a combined fault mode, when the slave BMS controller detects a module fault, performing a bypass to the faulty module; after the master BMS controller determines based on the total voltage that the faulty module cannot be disconnected, sending a module internal switch (BSC) disconnect command to another battery module adjacent to the faulty module, wherein the other battery module includes another slave BMS controller, the other slave BMS controller disconnecting the module internal switch (BSC) in the other battery module based on the disconnect command and sending the disconnected state of the module internal switch (BSC) to the master BMS controller; the master BMS controller closing a bypass switch corresponding to the other battery module and closing a first main bypass contactor (MBPC) corresponding to the faulty module.

[0017] According to an embodiment of the present invention, the method may include: in discharge equalization mode, when the main BMS controller receives a power equalization permission instruction sent by the BPCU, the main BMS controller performs power equalization control based on the module information collected from each BMS controller and the load information sent by the BPCU. The main BMS controller calculates and determines whether the system SoC range, the SoC range of modules within the system, the system SoP performance, and the system terminal voltage meet the corresponding conditions. When all the conditions are met, the main BMS controller performs bypass on the module with the lowest SoC and sends the number of working modules to the BPCU.

[0018] Compared with existing solutions, the high-voltage lithium battery control system and method for civil aircraft provided by this invention have at least the following advantages:

[0019] 1) It makes up for the shortcomings of existing high-voltage lithium battery systems that cannot meet the explosion safety requirements in airworthiness clauses and aviation standards. It solves the problems of fault isolation and thermal runaway / explosion containment of high-voltage lithium batteries through flexible recombination, which facilitates maintenance and replacement;

[0020] 2) The lithium battery module bypass control method based on master-slave BMS collaboration under the system architecture of this invention enables high-voltage lithium batteries to still be used with degraded performance in fault mode, which significantly improves safety and availability;

[0021] 3) It can proactively identify and define various potential problems in the actual operation of high-voltage lithium batteries for civil aircraft, laying a solid foundation for the early prevention and control of risks in subsequent applications.

[0022] These and other features and advantages will become apparent from the following detailed description and with reference to the accompanying drawings. It should be understood that the foregoing general description and the following detailed description are illustrative only and do not limit the scope of the claims. Attached Figure Description

[0023] To gain a more detailed understanding of the manner in which the features of the present invention are described above, reference can be made to various embodiments to provide a more specific description of the above-briefly summarized aspects, some of which are illustrated in the accompanying drawings. However, it should be noted that the drawings illustrate only certain typical aspects of the invention and should not be considered as limiting its scope, as this description may allow for other equivalent and effective aspects.

[0024] Figure 1 This is a schematic diagram of the physical architecture of a high-voltage lithium battery control system for a civil aircraft according to one aspect of the present invention.

[0025] Figure 2This is a schematic diagram of the control architecture and signal flow of a high-voltage lithium battery control system for a civil aircraft according to an embodiment of the present invention.

[0026] Figure 3 This is a schematic diagram of the architecture for battery module connection and bypass control of a high-voltage lithium battery control system for a civil aircraft according to an embodiment of the present invention.

[0027] Figure 4 This is a flowchart of a method for a high-voltage lithium battery control system for a civil aircraft according to another aspect of the present invention.

[0028] Figure 5 This is a schematic diagram of a method for controlling a high-voltage lithium battery for a civil aircraft according to another embodiment of the present invention in the normal operating mode of the system.

[0029] Figure 6 This is a schematic diagram of a method for a high-voltage lithium battery control system for a civil aircraft in a single-module failure mode according to another embodiment of the present invention.

[0030] Figure 7 This is a schematic diagram of a method for a high-voltage lithium battery control system for a civil aircraft under combined failure mode, according to another embodiment of the present invention.

[0031] Figure 8 This is a schematic diagram of a method for a high-voltage lithium battery control system for a civil aircraft in discharge equalization mode according to another embodiment of the present invention. Detailed Implementation

[0032] For ease of description, in this application, "main battery management system (BMS) controller" is uniformly referred to as "main BMS controller," and "slave battery management system (BMS) controller" is uniformly referred to as "slave BMS controller." Unless otherwise stated, "main BMS controller" and "slave BMS controller" in the following text refer to the full names mentioned above.

[0033] The present invention will now be described in detail with reference to the accompanying drawings, and its features will become further apparent in the following specific description.

[0034] Figure 1 A schematic diagram of the physical architecture of a high-voltage lithium battery control system 100 for a civil aircraft according to one aspect of the present invention is provided. Figure 1As shown, the high-voltage lithium battery control system 100 for civil aircraft may include multiple battery modules 102, each of which may include multiple lithium batteries, which may be connected in series or in parallel. The voltage range of each battery module 102 (e.g., in the case of internal series connection, the voltage range is determined by the number of internal series-connected cells) may be designed with reference to the 28V voltage level of existing civil aircraft batteries, which is conducive to module-level technology reuse; alternatively, the voltage of a single module may be increased to reduce the number of modules, which can directly reduce the connection complexity within the battery pack and reduce the amount of high-voltage connection cables, connectors, and fixing structures used between modules.

[0035] Each battery module 102 may include a BMS controller 104, which can be configured to collect module information from the battery module 102. Specifically, the BMS controller 104 can collect information about individual lithium battery cells and calculate module information based on this information. The individual lithium battery cell information collected by the BMS controller 104 includes, but is not limited to, cell voltage, cell temperature, and module current. The module information calculated based on the collected information includes, but is not limited to, the module's state of charge (SoC), state of power (SoP), various fault modes (open circuit, overcharge, over-discharge, thermal runaway, etc.), and alarm information (abnormal temperature rise alarm).

[0036] Each battery module 102 may also include an internal module switch (battery series contactor) BSC 106, which can be configured to be driven by the BMS controller to achieve the switching of this battery module with other battery modules forming a series circuit. Figure 1 As shown, the internal module switch BSC 106, used to disconnect the module from the series main circuit, and the corresponding slave BMS controller 104 are integrated inside the battery module. This makes the entire battery module a Line Replaceable Unit (LRU), which can be individually disassembled and quickly replaced, thereby significantly shortening the line fault handling time, enabling rapid module replacement and offline maintenance, and improving the overall operational efficiency. Furthermore, this design gives the module independent fault isolation and status control capabilities, simplifies system integration and spare parts management processes, and reduces long-term maintenance costs and system failure risks.

[0037] Each battery module 102 is also equipped with a separate exhaust channel for thermal runaway pressure relief and exhaust.

[0038] In embodiments of the present invention, the exhaust pipes of each module can be collected into a main pipe after passing through their respective one-way valves, and then connected to an opening in the fuselage skin. Alternatively, the exhaust pipes of each module can be completely independent and not collected, and each can be connected to a different opening in the fuselage skin. Throughout the exhaust process, the heat insulation structure of the channel can prevent high-temperature and high-pressure gases from being transmitted to other normal battery modules, and the filtration structure can prevent the diffusion of harmful substances. Thus, the hazards of thermal runaway combustion, explosion, and toxic gas leakage are completely confined within the battery module 102, preventing the risk from spreading to adjacent modules and the entire high-voltage battery system.

[0039] The high-voltage lithium battery control system 100 for civil aircraft may further include a high-voltage control module 108. The high-voltage control module 108 may include a bypass switch 110, which can be configured to perform bypass control on a corresponding module among multiple battery modules. The bypass switch 110 may include a first main bypass contactor (MBPC) and a second bypass contactor (BPC). The first MBPC and the second BPC differ in hardware structure. The first MBPC is located on the main circuit of the high-voltage control module 108, and its switching control performance is higher than that of the second BPC. It is also equipped with corresponding arc-extinguishing devices and anti-contact-erosion functions. When both the first MBPC and the second BPC need to be closed, the first MBPC closes later than the second BPC. This is because when the second BPC is closed first, the main circuit is in an "open circuit" state because the MBPC is not closed. There is no actual high voltage difference across the second BPC, and almost no current flows during the closing process, so no significant arc is generated, thus avoiding damage to the second BPC due to arcing. After the second switch BPC is closed, the main circuit has only one break point left: the first switch MBPC. Only by closing the first switch MBPC at this point can a complete circuit be formed. Although an arc will be generated due to the high voltage difference in the circuit when the first switch MBPC is closed, it is equipped with an arc-extinguishing device and an anti-contact-erosion function, which can quickly cut off the arc, dissipate the arc energy, and prevent the arc from burning and damaging the contacts and the circuit. The bypass switch 110 (e.g., the first switch MBPC and the second switch BPC) is logically interlocked with the module internal switch BSC 106. The corresponding bypass switch can only be closed after it is confirmed that the module internal switch BSC 106 is open.

[0040] The high-voltage control module 108 may also include a main BMS controller 112. The main BMS controller 112 can be configured to: receive module information from each slave BMS controller; calculate battery system status information based on the module information and report it to the high-voltage DC busbar power controller (BPCU); and control the module's internal switch (BSC) and bypass switch based on the information received from the BPCU and the module information. System status information that the main BMS controller 112 can send to the BPCU includes: system SoC, SoP, number of working modules, system fault alarms, and maximum allowable discharge time under the current load. The BPCU can send external system information such as mode commands (normal power supply, allowable charge balancing, etc.) and external load requirements (power, voltage, mission time) to the main BMS controller 112 as control inputs, depending on the current flight phase and mission importance. The main BMS controller 112 can also send drive signals for the module's internal switches to the slave BMS controller 104 as safety redundancy.

[0041] Figure 2 This document describes a schematic diagram of the control architecture and signal flow 200 for a high-voltage lithium battery control system for civil aircraft according to an embodiment of the present invention. Specifically, the BMS consists of a master BMS controller (BMS_Master) and n slave BMS controllers (BMS_Slave 1~n#) corresponding to each battery module, forming a master-slave architecture. The slave BMS controllers are responsible for collecting and monitoring the status of individual battery cells within each module and integrating this information into module information, which is then uploaded to the master BMS controller. The master BMS controller calculates the system status in real time based on the module information and reports the current status of the battery system to the high-voltage DC busbar power controller (BPCU) outside the system. When a battery failure occurs, the master BMS controller, in conjunction with the load demand and operating mode commands sent by the BPCU, coordinates with the slave BMS controllers of the module containing the faulty battery to sequentially control the internal switch BSC and the corresponding bypass switch in the high-voltage control module. This achieves bypass control of the battery module, maintains the system's power supply capability, and prevents system failure due to a single module failure.

[0042] Figure 2 The information exchange in the process mainly includes: module information (e.g., SoC, SoP, various fault modes and alarm information) sent from the BMS controller to the main BMS controller; system status information (e.g., system SoC, SoP, number of working modules, system fault alarms and maximum allowable discharge time under current load) sent from the main BMS controller to the BPCU; and external system information sent from the BPCU to the main BMS controller based on the current flight phase and mission importance.

[0043] Figure 3A schematic diagram of a battery module connection and bypass control architecture 300 for a high-voltage lithium battery control system for a civil aircraft, according to an embodiment of the present invention, is provided. Figure 3 As shown, the module internal switches BSC 1~n are module internal switches driven by the respective BMS controllers, which can be used to disconnect the module from the system main circuit. The first switch MBPC 1~n and the second switch BPC 1~(n-1) are (2n-1) bypass switches driven by the main BMS controller, which can be used to implement bypass control of the faulty module and to perform power balancing function between modules. As mentioned above, there is a logical interlock between the bypass switches (e.g., the first switch MBPC and the second switch BPC) and the module internal switches BSC. Only after the main BMS controller confirms that the module internal switch BSC is open can the corresponding bypass switches (e.g., the first switch MBPC and the second switch BPC) be closed in sequence, and the first switch MBPC closes later than the second switch BPC to control the impact of arcing. The redundant switch physical structure formed by the first switch MBPC and the second switch BPC can effectively avoid module short circuits caused by short circuits in the bypass circuit, and at the same time, effectively avoid serious damage to the system caused by the failure of a single bypass switch.

[0044] Figure 4 A flowchart illustrating a method 400 for a high-voltage lithium battery control system for a civil aircraft according to another aspect of the present invention is provided. Method 400 can be performed by, for example... Figure 1 The high-voltage lithium battery control system 100 for civil aircraft shown is executed. The method 400 for the high-voltage lithium battery control system for civil aircraft may include: step 402 acquiring module information from the corresponding battery module from the BMS controller; step 404 the main BMS controller receiving the module information acquired from each sub-BMS controller; step 406 the main BMS controller calculating battery system status information based on the module information and reporting it to the high-voltage DC busbar power controller (BPCU); and step 408 the main BMS controller controlling the module internal switches (BSC and bypass switches) based on the information received from the BPCU and the module information.

[0045] This method achieves module isolation by independently collecting module information from the BMS controller and precisely controlling the bypass switch by the main BMS controller, ensuring degraded operation under battery system failure and avoiding global power interruption. The main BMS controller combines module data with BPCU commands for collaborative decision-making, preventing fault propagation and overloading of remaining modules, thus constructing a dual safety guarantee. This fault-tolerant design conforms to civil aircraft airworthiness standards and is suitable for the multi-power source coordination requirements of civil aircraft.

[0046] Figure 5A schematic diagram 500 illustrates a method for controlling a high-voltage lithium battery system for a civil aircraft according to another embodiment of the present invention in the normal operating mode of the system.

[0047] In normal operating mode, when the main BMS controller receives a normal power supply command from the BPCU, it first verifies the validity of the command. This verification includes the legality of the command code, the matching degree of the power supply, and the current insulation status of the system. After successful verification, the main BMS controller synchronously sends module internal switch (BSC) closing commands to all slave BMS controllers (1~n). These commands include the target switch action sequence, closing delay threshold, and status feedback requirements to ensure the reliability and consistency of command transmission. Once all BSCs are confirmed closed, the BPCU controls the main contactor to close, connecting the lithium battery system to the high-voltage DC busbar.

[0048] Upon receiving the BSC (Battery Controller System) closure command from the master BMS controller, each slave BMS controller immediately initiates a local battery module fault self-test process. This self-test process may include: electrical parameter self-test, thermal condition self-test, and switch status self-test. If the slave BMS controller determines that the corresponding battery module is fault-free (all self-test parameters are within the preset safety threshold range), it responds to the master BMS controller's command.

[0049] After completing the fault self-check and determining that the module is fault-free, the BMS controller drives the corresponding battery module's internal switch (BSC) to close according to the instructions. Simultaneously, while all module internal switches (BSC 1~n) are closed, the bypass switches corresponding to all battery modules in the system remain open and locked. Specifically, the first switch (MBPC 1~n) and the second switch (BPC 1~(n-1)) remain open, and all battery modules... Figure 5 The system is connected in series as shown. At this time, the system can output power according to the preset power output specified by the BPCU command. The main BMS controller monitors the total voltage, total current, and operating parameters of each module in the series circuit in real time to ensure the system is in a stable power supply state.

[0050] Figure 6 A schematic diagram 600 illustrates a method for a high-voltage lithium battery control system for a civil aircraft according to another embodiment of the present invention in a single-module failure mode.

[0051] In the single-module fault mode of the system, when all battery modules are connected in series and supplying power normally, if a slave BMS controller (e.g., BMS_Slave 2#) detects a fault in a battery module (e.g., battery module 2), the slave BMS controller reports the fault information to the master BMS controller and coordinates with the master BMS controller to perform bypass control. Specifically, after receiving and confirming the control command to disconnect the series circuit sent by the master BMS controller, the slave BMS controller (e.g., BMS_Slave 2#) first controls the internal switch BSC 2 of the module to open, thereby cutting off the series main circuit between battery module 2 and the system, and simultaneously feeds back the open state of the internal switch BSC 2 of the module to the master BMS controller; after receiving the open state of the internal switch BSC 2 of the module, the master BMS controller controls the bypass switches (e.g., second switch BPC 2, second switch BPC 1, first switch MBPC 2) to close, thereby bypassing battery module 2, so that the remaining (n-1) battery modules of the system continue to supply power in series, such as Figure 6 As shown in the figure. In one embodiment of the invention, when the main BMS controller does not respond to a fault reported by the sub-BMS controller to the main BMS controller (e.g., a fault in the main BMS controller or an interruption in communication between the sub-BMS controller and the main BMS controller), and when the fault would cause serious consequences (e.g., a thermal runaway fault), the sub-BMS controller may also automatically drive the disconnection of the module's internal switch BSC.

[0052] In single-module failure mode, if the BMS controller (e.g., BMS_Slave 2#) detects an abnormal state of a battery module (e.g., module 2) (e.g., abnormal temperature rise, abnormal internal resistance, etc.), it can coordinate with the main BMS controller to preemptively control the bypass of that battery module, preventing thermal runaway caused by the deterioration of the faulty module's state and reducing the probability of the faulty module emitting smoke and catching fire. Simultaneously, when thermal runaway occurs in a faulty module, it can also release pressure and vent air through internal channels, thereby preventing the thermal runaway from spreading to other battery modules.

[0053] Figure 7 A schematic diagram 700 illustrates a method for a high-voltage lithium battery control system for a civil aircraft according to another embodiment of the present invention in a combined fault mode.

[0054] In the combined fault mode of the system, when a fault is detected in battery module 2 by the BMS controller (e.g., BMS_Slave 2#), the slave BMS controller feeds back the fault information to the master BMS controller and coordinates with the master BMS controller to perform bypass control. After receiving the control command to disconnect the series circuit from the master BMS controller, the slave BMS controller (e.g., BMS_Slave 2#) can first control the internal switch BSC 2 of the module to open, thereby cutting off the series main circuit between battery module 2 and the system, and simultaneously feed back the open state of the internal switch BSC 2 of the module to the master BMS controller; after receiving the open state of the internal switch BSC 2 of the module, the master BMS controller controls the bypass switches (e.g., second switch BPC 2, second switch BPC 1, first switch MBPC 2) to close, thereby bypassing battery module 2, so that the remaining (n-1) battery modules of the system continue to supply power in series.

[0055] After issuing the BSC 2 disconnect command, the main BMS controller enters a status monitoring window (e.g., a preset duration of 50ms~100ms). It identifies the combined fault condition of "faulty module cannot disconnect" through the following dual-judgment logic: Electrical parameter judgment: The main BMS controller collects the total voltage of the system's series main circuit, the voltage across battery module 2, and the circuit current in real time. If the total voltage does not show the expected change of "single module voltage drop," and there is still current flowing across battery module 2, it can be determined that BSC 2 has a contact adhesion fault. Safety status judgment: If the main BMS controller receives information such as "module internal pressure exceeds limit" or "pressure relief trigger terminal activated" reported from the BMS controller (e.g., BMS_Slave 2#), it can be determined that battery module 2 has experienced thermal runaway, and BSC 2 cannot disconnect due to high-temperature welding. When any of the above judgment conditions are met, the main BMS controller immediately determines that the system has entered a combined fault mode and initiates the adjacent module linkage bypass strategy.

[0056] Specifically, the master BMS controller can send a command to the slave BMS controller (e.g., BMS_Slave 1) to disconnect the internal BSC 1 switch of the module, where the battery module to which the slave BMS controller belongs is adjacent to the faulty battery module. When the slave BMS controller BMS_Slave 1 executes this command and reports back to the master BMS controller that the internal switch BSC 1 of the module is disconnected, the master BMS controller can control the corresponding bypass switches (e.g., second switch BPC 2, first switch MBPC 2, first switch MBPC 1) to close, such as... Figure 7 As shown in the image.

[0057] After the bypass circuit is activated, battery modules 1 and 2 are simultaneously isolated from the system's series main circuit. The remaining (n-2) normal battery modules continue to be powered in series through the bypass branch. The main BMS controller calculates the battery system's state of power (SoP) and the maximum allowable discharge time under the current load in real time, and reports this system information to the BPCU. The BPCU then determines, based on the load operating status and aircraft commands, whether to compensate for the voltage drop of the high-voltage DC busbar caused by the isolation of the two modules, and performs load dumping.

[0058] Figure 8 A schematic diagram 800 illustrates a method for a high-voltage lithium battery control system for a civil aircraft in discharge equalization mode according to another embodiment of the present invention.

[0059] In the system's discharge equalization mode, when the main BMS controller receives the charge equalization permission command sent by the BPCU, it first initiates a command validity verification. The verification includes the equalization command's permission level, validity period, and the communication link status between the BPCU and the main BMS controller, ensuring the command is legal and valid. After successful verification, the main BMS controller sends module information acquisition commands to all slave BMS controllers (1~n), synchronously acquiring the core status parameters of each battery module. These parameters may include: module state of charge (SoC), module power state (SoP), individual cell voltage, inter-cell voltage range, module temperature, and individual cell internal resistance. Simultaneously, it receives real-time load information from the BPCU, which may include the load's rated power, operating voltage range, and instantaneous power fluctuation value, providing data support for subsequent equalization condition determination.

[0060] Based on the collected module information and load data, the main BMS controller can sequentially calculate and determine whether all of the following four core conditions are met:

[0061] 1. System SoC Range: Whether the system SoC is within the balancing range (e.g., set to 40%~90%). Setting this range avoids balancing operations when the battery is fully charged (SoC > 90%) or depleted (SoC < 40%), preventing damage to individual battery cells due to overcharging or over-discharging. If the system average SoC is within this range, then condition 1 is satisfied;

[0062] 2. System Module SoC Range: Does the SoC range between modules exceed a threshold (e.g., set to 5%~8%)? When the range exceeds the threshold, it indicates that the difference in charge between modules is too large, which has affected the system discharge efficiency, aircraft turnaround time, and battery life. In this case, condition 2 is satisfied.

[0063] 3. System SoP Performance: After bypass control, whether the predicted SoP value of the system is higher than the load demand (for example, the predicted SoP value is required to be ≥ 1.0 times the rated load power to ensure that the system can stably carry the load and work continuously, and the predicted SoP value is required to be ≥ 1.1 times the instantaneous peak load power to cope with the short-term power fluctuation impact of the load) and meets the power safety margin (for example, the preset power safety margin threshold can be set to 10%~20%, and when the calculated margin value is ≥ the threshold, it is determined that the safety margin requirement is met). Condition 3 is met when both of the above two sub-conditions are met.

[0064] 4. System terminal voltage: Whether the predicted value of the system terminal voltage after bypass control meets the load's demand for the high-voltage DC bus voltage. Specifically, determine whether the system terminal voltage when the load is working is within the rated operating voltage range of the load (e.g., 540V~700V), and whether the voltage after fluctuation is within the allowable voltage fluctuation threshold of the load (e.g., ±5%). If both the above system terminal voltage and fluctuation value meet the load voltage requirements, then condition 4 is satisfied.

[0065] If all the above conditions are met, the main BMS controller can bypass the battery module with the lowest control SoC (e.g., battery module 2), such as... Figure 8 As shown, the main BMS controller then feeds back system information such as the number of working modules to the BPCU. At this time, the remaining (n-1) battery modules in the system are powered in series, the bypassed battery module 2 stops discharging and enters a static state, and the remaining modules continue to discharge until the SoC and the module tend to be consistent, thus achieving power balance.

[0066] If the SoC of battery module 2 is equal to the system SoC, or if any of the conditions 1, 3, or 4 above are not met, or if a normal power supply command is received from the BPCU, priority must be given to ensuring the power supply capability of all modules in the system. In this case, the main BMS controller must work with the slave BMS controller (e.g., BMS_Slave 2) to reconnect battery module 2 to the series main circuit. Specifically, the main BMS controller will perform the operation in the order of "first disconnecting the bypass switch, then closing the module's internal switch BSC" to avoid current surges. After the switching action is completed, the system can restore the series power supply state of all normal modules.

[0067] The foregoing description includes examples of various aspects of the claimed subject matter. It is certainly impossible to describe every conceivable combination of components or methods for the purpose of depicting the claimed subject matter, but those skilled in the art will recognize that many further combinations and arrangements of the claimed subject matter are possible. Thus, the disclosed subject matter is intended to cover all such changes, modifications, and variations that fall within the spirit and scope of the appended claims.

Claims

1. A high-voltage lithium battery control system for civil aircraft, characterized in that, The control system includes: Multiple battery modules connected in series to form a series circuit, each battery module comprising: Multiple lithium batteries; Configure the Battery Management System (BMS) controller to collect module information from the battery module; and The internal switch battery series contactor (BSC) of the module is configured to be driven by the BMS controller to realize the connection and disconnection of the battery module and the series circuit. The high-voltage control module includes: A bypass switch is configured to perform bypass control on a corresponding module among the plurality of battery modules; The main battery management system (BMS) controller is configured as follows: Receive module information sent from each BMS controller; Based on the module information, calculate the battery system status information and report it to the high-voltage DC busbar power controller (BPCU); and The module's internal switch BSC and bypass switch are controlled based on information received from the BPCU and the module information.

2. The system as described in claim 1, characterized in that, The module information includes one or more of the following: module state of charge (SoC), state of power (SoP), fault mode, and alarm information. The fault mode includes one of the following: open circuit fault, overcharge fault, over-discharge fault, or thermal runaway fault. The alarm information includes an abnormal temperature rise alarm.

3. The system as described in claim 1, characterized in that, The battery system status information includes one or more of the following: system state of charge (SoC), system power state (SoP), number of working modules, system fault alarms, and maximum allowable discharge time under the current load. The information received from the BPCU includes mode commands and external load requirements. The mode commands include one of normal power supply and allowable power balancing. The external load requirements include one or more of power, voltage, and task time.

4. The system as described in claim 1, characterized in that, The bypass switch includes a first main bypass contactor MBPC and a second bypass contactor BPC. When both the first main bypass contactor MBPC and the second bypass contactor BPC are to be closed, the first switch MBPC closes later than the second switch BPC to control the impact of the electric arc. There is a logical interlock between the bypass switch and the module internal switch BSC, wherein the corresponding bypass switch can only be closed after it is confirmed that the module internal switch BSC is open.

5. The system as described in claim 1, characterized in that, Each battery module has a separate venting channel for thermal runaway pressure relief and venting.

6. A method for controlling a high-voltage lithium battery in a civil aircraft, characterized in that, The high-voltage lithium battery control system includes: Multiple battery modules connected in series to form a series circuit, each battery module comprising: Multiple lithium batteries; From the battery management system (BMS) controller; and The module's internal switch battery series contactor BSC; The high-voltage control module includes: Bypass switch; and Main Battery Management System (BMS) controller; The method includes the following steps: Collect module information from the corresponding battery module from the BMS controller; The main BMS controller receives module information collected from each BMS controller; The main BMS controller calculates battery system status information based on the module information and reports it to the high-voltage DC busbar power controller (BPCU); and The main BMS controller controls the module's internal switch BSC and the bypass switch based on information received from the BPCU and the module information.

7. The method of claim 6, wherein the method comprises: In normal working mode When the main BMS controller receives a normal power supply command sent by the BPCU, the main BMS controller sends a command to the slave BMS controller to close the module's internal switch BSC. The BMS controller closes the internal switch BSC of the module. The bypass switch remains in the off state.

8. The method of claim 6, wherein the method comprises: In single-module failure mode When a module fault is detected by the BMS controller, a bypass is performed on the faulty module. The bypass of the faulty module includes: The module's internal switch BSC is disconnected from the BMS controller, and the fault information of the faulty module and the disconnection status of the module's internal switch BSC are sent to the main BMS controller. The main BMS controller controls the closing of the bypass switch corresponding to the faulty module based on the open state of the internal switch BSC of the module.

9. The method of claim 6, wherein the method comprises: In combined failure mode When a module fault is detected by the BMS controller, a bypass is performed on the faulty module. After the main BMS controller determines that the faulty module cannot be disconnected based on the total voltage, it sends a command to disconnect the internal switch (BSC) of another battery module adjacent to the faulty module. This other battery module includes another slave BMS controller. The other slave BMS controller disconnects the module internal switch (BSC) within the other battery module based on the disconnect command and sends the disconnect status of the module internal switch (BSC) to the master BMS controller. The main BMS controller closes the bypass switch corresponding to the other battery module and closes the first main bypass contactor MBPC corresponding to the faulty module.

10. The method of claim 6, wherein the method comprises: In discharge equalization mode When the main BMS controller receives the power balancing permission command sent by the BPCU, The main BMS controller performs power balancing control based on the module information collected from each BMS controller and the load information sent by the BPCU. The main BMS controller calculates and determines whether the system SoC range, the SoC range of modules within the system, the system SoP performance, and the system terminal voltage meet the corresponding conditions. When all the conditions are met, the main BMS controller performs a bypass on the module with the lowest SoC and sends the number of working modules to the BPCU.

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