Multi-battery pack charging management system and method and engineering machinery

Abstract

The invention discloses a multi-battery-pack charging management system and method and engineering machinery, and the system comprises a VCU which is configured to execute the starting control of a whole vehicle, the logic scheduling of a charging process, the cooperative management of high-voltage parts, and the processing of an abnormal state; the number of the battery packs is multiple, each battery pack is internally provided with an independent BMS, and the BMS is configured to monitor the running state of the battery packs in real time; the PDU relay is integrated with positive and negative pole contactors corresponding to the battery packs and a PDU auxiliary loop contactor connected in series with the DCDC high-voltage power supply loop; the DCDC is configured to convert the high-voltage direct current output by the battery pack into low-voltage direct current, and the working state of the DCDC is regulated and controlled by the VCU; the charging gun has an anti-misplug mechanical structure and a safe locking function. The multi-battery-pack parallel charging function of the vehicle under any working condition can be achieved, cooperative work and safe operation of all the battery packs and high-voltage components in the charging process are ensured, and the charging efficiency and the system reliability are effectively improved.

Description

TECHNICAL FIELD

[0001] The application relates to a multi-battery pack charging management system, method and engineering machinery, and belongs to the field of engineering machinery. BACKGROUND

[0002] With the rapid development of new energy engineering machinery, multi-battery systems gradually become the mainstream configuration with higher energy reserves and endurance. However, compared with single-battery systems, the charging management of multi-battery systems faces more complex technical challenges: precise coordination of the working time sequence of each battery pack and high-voltage components (such as high-voltage switching boxes and DCDC) is required to ensure the safe access and exit of the high-voltage system during charging, and to avoid safety hazards or charging failures caused by management logic defects. The current multi-battery system charging management field lacks systematic and logical process design, making it difficult to meet the increasing safety and reliability requirements in engineering applications, and there is an urgent need to build an optimized charging management scheme.

[0003] The traditional battery charging management scheme has significant limitations, and the core problem is that it follows the single-battery control logic without special design for the independence and collaboration of multi-battery: first, there is a lack of independent detection mechanism for the charging gun insertion signal of each battery pack, the high-voltage instruction sending lacks standardization, and the precise identification of the first charging state is not realized; second, the power-off process design is simple and extensive, without considering the charging state differences of multi-battery (such as some batteries being fully charged while others still being charged), directly executing unified power-off operation, which easily leads to process conflicts.

[0004] The existing multi-battery pack charging management system also has the following key defects:

[0005] (1) Low efficiency: using a synchronous charging mode without priority, relying on a fixed charging sequence, which cannot realize the parallel charging start of multi-battery packs, leading to increased overall charging time.

[0006] (2) Process confusion: without distinguishing between first charging and non-first charging states, the core operations such as high-voltage and power-off lack targeted control, which easily leads to operation conflicts between battery packs (such as simultaneous execution of incompatible actions), significantly reducing the charging success rate.

[0007] (3) Lack of abnormal response: there is a lack of standardized processing mechanism for abnormal scenarios such as charging interruption, contactor sticking, and DCDC high-voltage failure, which may lead to non-safe power-off or misoperation risk of the high-voltage system.

[0008] (4) Insufficient compatibility: the newly connected battery pack after the charging gun is plugged in cannot dynamically join the existing charging sequence, and the entire charging process needs to be restarted, which seriously affects the charging continuity. SUMMARY

[0009] In view of the problems in the prior art, the application provides a multi-battery pack charging management system and method and engineering machinery, which can realize the parallel charging function of the vehicle under any working condition, ensure the cooperative work and safe operation of the battery packs and high-voltage components during the charging process, and effectively improve the charging efficiency and system reliability.

[0010] In order to achieve the above-mentioned purpose, the application adopts a multi-battery pack charging management system, which comprises:

[0011] The VCU is configured to perform vehicle starting control, charging flow logic scheduling, high-voltage component cooperative management and abnormal state processing.

[0012] The battery packs are provided in multiple numbers, each of which is provided with an independent BMS, and the BMS is configured to monitor the running state of the battery pack in real time, and each battery pack supports charging and battery replacement operations.

[0013] The PDU relay is integrated with positive and negative pole contactors corresponding to each battery pack and a PDU auxiliary circuit contactor connected in series to the DCDC high-voltage power supply circuit, and the positive and negative pole contactors are used to control the high-voltage circuit on-off of the corresponding battery pack.

[0014] The DCDC is configured to convert the high-voltage direct current output by the battery pack into low-voltage direct current, and its working state is controlled by the VCU.

[0015] The charging gun has a mistaken insertion prevention mechanical structure and a safety locking function, and outputs an A+ wake-up signal after the gun is inserted, which is transmitted to the BMS wake-up interface of the corresponding battery pack and the wake-up input end of the VCU, so as to activate the BMS and the VCU to enter the charging preparation state.

[0016] The VCU is connected with the BMS, the PDU relay and the DCDC of the battery pack through the CAN communication bus to realize real-time data interaction, and is connected with the contactor coil of the PDU relay and the enable end of the DCDC through the hard-wire control circuit; the battery pack is connected with the positive and negative pole contactors of the PDU relay through the high-voltage interface, and the charging gun is connected with the charging port of the battery pack through the charging interface.

[0017] As an improvement, the VCU is configured to receive the A+ wake-up signal of the charging gun through the hard-wire connection, receive the state feedback signals of the BMS, the PDU relay and the DCDC of the battery pack through the CAN communication bus, and send the on-off instructions to the contactor coil of the PDU relay and the enable control instructions to the DCDC based on the state feedback signals.

[0018] As improved, the BMS of the battery pack is configured to monitor the running state in real time, including cell voltage, total voltage, charging and discharging current, cell temperature and state of charge SOC; each battery pack is connected with the positive and negative contactors of the PDU relay through a high-voltage interface, and the output end of the positive and negative contactors is connected with the high-voltage bus of the whole vehicle to provide power output for the whole vehicle.

[0019] As improved, the coil control end of the positive and negative contactors in the PDU relay is connected with the driving interface of the VCU, and is used for receiving the on-off instruction of the VCU; the contact state signal of the PDU auxiliary circuit contactor is fed back to the VCU through a signal line, and is used for feeding back the high-voltage access state of the DCDC in real time.

[0020] As improved, one end of the charging gun is provided with a power supply interface matched with an external charging pile, and the other end is provided with a charging interface matched with a corresponding battery pack charging port; after the gun insertion action is completed, the mechanical locking mechanism in the charging gun is triggered, and the charging cabinet synchronously activates the BMS and the VCU from the sleep state to the charging preparation state through the A+ wake-up signal output by the built-in signal line in the charging gun.

[0021] The second aspect of the application also provides a multi-battery pack charging management method based on the multi-battery pack charging management system, comprising the following steps:

[0022] S1, a charging initialization stage: connecting each battery pack charging gun to the corresponding interface, and waking up the VCU through the gun insertion action; the VCU starts a system health pre-check process, and sequentially detects that the whole vehicle has no three-level fault, the positive and negative contactors in the power distribution unit have no adhesion, and the communication link between the BMS and the PDU and the DCDC is unobstructed; after the pre-check is passed, a unique serial number is assigned to each BMS according to the charging gun connection order, and the initial charging state is marked;

[0023] S2, a charging start control stage: the VCU executes a hierarchical activation strategy, preferentially controls serial number BMS A to close the PDU contactor in the order of negative contactor to positive contactor, simultaneously activates the DCDC to make BMS A enter the charging state, and the remaining BMSs synchronously complete the high-voltage loop connection to realize parallel charging; each BMS uploads the charging completion, gun pulling and high-voltage closing request signals to the VCU in real time;

[0024] S3, a dynamic running state processing stage: different control is executed for different running states, including:

[0025] When BMS A is fully charged and part of the battery packs are not fully charged, the VCU disables the DCDC and disconnects the BMS A contactor, reactivates the remaining BMSs and updates the serial number and non-first charging state;

[0026] When the BMSA is full or not started, the VCU executes the DCDC shutdown, the PDU auxiliary circuit high voltage and the vehicle power down operation in sequence;

[0027] When the BMSA is interrupted in the middle of charging and other BMSs are still charging, an emergency switching mechanism is triggered to ensure the remaining battery pack charging; when the battery pack that has completed charging is plugged in again, it is accessed as a new BMS and marked as "non-first charging", and after 1 minute of plugging in, the A+ signal is detected to resume charging;

[0028] When the BMSA is not full, the corresponding BMS is automatically powered off and waits to be activated or uniformly shut down.

[0029] As an improvement, in the dynamic running state processing stage, when the BMSA is full and some battery packs are not full, the following sub-steps are included:

[0030] The VCU sends a disable instruction to the DCDC and performs a high voltage operation on the PDU auxiliary circuit; after the DCDC is completely powered off, the BMSA is disconnected from the positive and negative contactors to exit the high voltage state; the corresponding negative and positive contactors of the BMSB are sequentially closed to reactivate the DCDC to ensure continuous charging of the remaining battery packs; the remaining battery packs are reordered, the original BMSB is marked as a new BMSA and is assigned a "non-first charging" state.

[0031] As an improvement, it also includes a contactor interlocking safety control step: to prohibit the positive and negative contactors of different BMSs from being attracted at the same time, when it is detected that the contactor of a certain BMS is in a closed state, the VCU locks the contactor drive signal of other BMSs until the contactor of the BMS is completely disconnected to unlock, avoiding the mutual charging risk between battery packs due to voltage difference.

[0032] As an improvement, it also includes a "non-first charging" state management step: the battery pack that reenters the charging sequence or completes the switching is marked as "non-first charging" state; after a 60-second delay detection, the VCU allows the high voltage connection process of the battery pack to be triggered again to prevent the full battery pack from entering a charging dead loop and eliminate the control logic blind area.

[0033] The third aspect of the present application also provides an engineering machine, wherein the engineering machine is installed with the multi-battery pack charging management system.

[0034] Compared with the prior art, the present application has the following advantages:

[0035] (1) Strengthen the safety protection ability: the VCU of the application carries out comprehensive fault detection and state judgment on the whole vehicle, including confirming no three-level fault, contactor not sticking, normal communication, etc., from the source to block potential safety hazards; by designing the contactor interlocking logic, strictly prohibiting the simultaneous attraction of positive and negative contactors of different battery packs, completely avoiding the risk of cross-group mutual charging caused by battery voltage difference, effectively preventing abnormal conditions such as overcharging and overdischarging, and significantly improving the intrinsic safety of the charging process.

[0036] (2) Significantly improve the charging efficiency: adopt the charging scheduling mechanism of "parallel start + dynamic switching", support multiple battery packs to start charging simultaneously, break through the efficiency bottleneck of fixed sequence charging; when part of the battery packs complete charging, the system can quickly transfer high-voltage resources to the remaining battery packs, without waiting for all the batteries to be fully charged to gradually advance the charging process, maximize the use of charging equipment power, and greatly shorten the overall charging time.

[0037] (3) Optimize intelligent control logic: introduce the "non-first charging" state marking mechanism, accurately distinguish the charging stage of the battery pack, fundamentally avoid the dead loop problem of mis-triggering secondary charging after the battery is fully charged, and ensure the smoothness of the charging process; the marking eliminates the operation blind area in the traditional control logic by simplifying the process judgment steps when switching the battery pack, making the charging sequence scheduling more adaptive and intelligent.

[0038] (4) Enhance system reliability: build a "BMS real-time monitoring + VCU global coordination" whole-process management system, each battery pack real-time feedbacks the charging completion, gun pulling signal, high-voltage request, etc., and realizes dynamic adjustment through the linkage response of VCU, PDU and DCDC; standardize the processing strategy for abnormal scenarios such as midway gun pulling and re-plugging, ensure the stable operation of the system under complex conditions, and greatly reduce the probability of failure downtime.

[0039] (5) Improve the efficiency of equipment management: the unified charging management logic makes the charging state of multiple battery packs visualized, and the standardized operation process and state marking (such as first / non-first charging, fault code, etc.) provide clear guidance for operation and maintenance; maintenance personnel can quickly locate the fault node based on standardized state data, significantly reduce the difficulty of equipment maintenance, and effectively save management cost. BRIEF DESCRIPTION OF DRAWINGS

[0040] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creating any inventive labor.

[0041] Figure 1The system structure diagram of the present application;

[0042] Figure 2A The battery execution flow chart of BMSA in the present application Figure 1 (Front part);

[0043] Figure 2B The battery execution flow chart two (rear part) of BMSA in the present application;

[0044] Figure 3 The battery execution flow chart of BMSB to BMSN in the present application;

[0045] In the figure: 1, VCU, 2, battery pack, 3, PDU relay, 4, DCDC, 5, charging gun. DETAILED DESCRIPTION

[0046] In order to make the purpose, technical scheme and advantages of the present application more clear and obvious, the technical scheme of the present application is described in detail below through specific examples, and it should be understood that the examples and specific features in the examples of the present application are detailed description of the technical scheme of the present application, rather than limitation of the technical scheme of the present application, and the technical features in the examples and the examples can be combined with each other without conflict.

[0047] Example 1

[0048] As shown in Figure 1 , Figure 2A , Figure 2B A multi-battery pack charging management system, including a vehicle control unit (VCU), a plurality of battery packs, a power distribution unit relay (PDU relay), a direct current voltage converter (DCDC) and a charging gun 5, each component works through communication bus and hard-wire loop to realize safe and efficient charging management of multi-battery pack.

[0049] The specific structure and function of the multi-battery pack charging management system are as follows:

[0050] VCU 1, as the core control unit of the system, integrates charging logic scheduling module, high-voltage cooperative management module and abnormality processing module, which is configured to:

[0051] Perform vehicle charging start control, charging flow timing scheduling, action coordination of each high-voltage component and emergency processing of abnormal state;

[0052] The VCU 1 establishes real-time data interaction with the battery management system BMS of the battery pack 2, the state monitoring module of the PDU relay 3 and the communication interface of the DCDC 4 through the CAN communication bus, and receives the state feedback signals of each component in real time (including the battery SOC, the contactor state, the DCDC working mode and the fault code, etc.), and sends accurate control instructions to each component based on the feedback signals;

[0053] The VCU 1 receives the A+ wake-up signal of the charging gun 5 through hard-wired connection (such as 12V level signal), triggers itself to switch from sleep state to working state, and synchronously wakes up the related high-voltage components;

[0054] The battery pack 2 is provided with a plurality of battery packs 2, each of which has charging and discharging and fast battery replacement functions, specifically including:

[0055] Each battery pack 2 is provided with a standard high-voltage interface and a charging port, wherein the high-voltage interface is connected with the corresponding positive and negative contactor input end of the PDU relay 3 through a high-voltage cable, and is used for outputting power to the vehicle high-voltage bus; the charging port adopts a foolproof design and is mechanically matched with the connection end of the charging gun 5;

[0056] The PDU relay 3 is integrated in the power distribution unit and is the core executive component of the high-voltage loop on-off control, including:

[0057] Positive and negative contactors: corresponding to the battery pack 2 (i.e. N battery packs are configured with N sets of positive and negative contactors), the input end of each set of contactors is connected with the high-voltage output end of the corresponding battery pack 2 through a copper bar, and the output end is connected to the vehicle high-voltage bus through a copper bar; the contactor coil control end is connected with the driving interface (PWM driving signal) of the VCU 1, receives the on-off instruction (high level on, low level off) of the VCU 1, and realizes accurate on-off control of the corresponding battery pack high-voltage loop;

[0058] PDU auxiliary loop contactor: connected in series with the high-voltage power supply loop of the DCDC 4, the contact state (closed / opened) is fed back to the VCU 1 in real time through a signal line, and is used for accurately representing the high-voltage access state (the contact closed corresponds to the high-voltage has been accessed, and the contact opened corresponds to the high-voltage has not been accessed) of the DCDC 4;

[0059] The DCDC 4 is configured as a high-low voltage conversion core component:

[0060] The input end is connected with a high-voltage bus of a whole vehicle through a high-voltage cable, receives high-voltage direct current (input voltage range 200-800V) output by the battery pack 2, and converts the high-voltage direct current into low-voltage direct current of 27.5V±0.5V to provide power supply and charging power for a vehicle-mounted small battery (12V / 24V);

[0061] An enable control end (connected with a hard-wire driving interface of the VCU 1) is arranged, and a working state is regulated by a control instruction of the VCU 1 (high level enables start, low level disables shutdown);

[0062] The DCDC 4 feeds back working states (including output voltage, output current and conversion efficiency) and fault information (including overvoltage, overcurrent and overheating) to the VCU 1 in real time through a CAN communication bus;

[0063] The charging gun 5 is a connecting component of the system and an external charging pile, and has mechanical safety protection and electrical awakening functions, and is specifically designed as follows:

[0064] One end is provided with a standardized power supply interface (in line with GB / T 20234.3 standard) matched with the external charging pile, and the other end is provided with a special-shaped connecting end matched with a charging port of the battery pack 2, and the connecting end is integrated with a mistaken insertion prevention structure (including a plurality of foolproof pins and special-shaped positioning grooves) to prevent different battery pack interfaces from being mixed and inserted;

[0065] A mechanical locking mechanism is arranged in the charging gun 5, when the insertion depth reaches a preset threshold (≥90% insertion depth), the mechanical buckle is automatically triggered to lock, so that the physical connection is stable during the charging process, and the locking state is transmitted to the VCU 1 through a feedback signal;

[0066] After the insertion action is completed, the external charging cabinet outputs an A+ awakening signal (12V direct current voltage, continuous output) through an independent signal line arranged in the charging gun, the signal is transmitted to a BMS awakening interface of the corresponding battery pack 2 and an awakening input end of the VCU 1 respectively, and the BMS and the VCU 1 are activated from a sleep state to a charging preparation state.

[0067] The connection relationship of the multi-battery pack charging management system includes:

[0068] Communication connection: the VCU 1 establishes a data link with the BMS of each battery pack 2, the state monitoring module of the PDU relay 3 and the communication interface of the DCDC 4 through a CAN communication bus respectively, so that parameter interaction and instruction transmission are realized;

[0069] Hard-wire control: the VCU 1 is connected with a contactor coil of the PDU relay 3 and an enable end of the DCDC 4 through a hard-wire driving circuit (with a 10A fuse), and outputs a PWM control signal;

[0070] Charging connection: the charging gun 5 realizes mechanical locking and electrical conduction with the charging port of the battery pack 2 through the charging interface (mechanical locking first and electrical connection later, time interval ≥ 500 ms), and the wakeup signal line thereof is connected with the BMS wakeup end (independent 12V loop) of the battery pack 2 and the wakeup end (hard-wire interface) of the VCU 1 respectively, to ensure reliable transmission of the wakeup signal.

[0071] Embodiment 2

[0072] As shown in Figure 1 , Figure 2A , Figure 2B and Figure 3 , in the charging scene of the multi-battery pack engineering machinery whole vehicle, the system realizes safe and efficient operation of the charging process through hierarchical logic control, and the specific process is as follows:

[0073] I. Charging initialization phase

[0074] Before charging, each battery pack charging gun needs to be accurately connected to the corresponding interface, and the vehicle controller (VCU) is woken up immediately after the gun insertion action is triggered. The VCU 1 starts the system health pre-check process immediately, and completes three core detections in turn: confirming that the whole vehicle has no level three fault; there is no adhesion phenomenon of all positive and negative contactors in the power distribution unit (PDU); the communication link between the battery management system (BMS) and the PDU and the direct current converter (DCDC) is unobstructed. After the pre-check is passed, the VCU 1 assigns a unique serial number (for example: BMS A, BMS B...BMS N) to the BMS of each battery pack 2 according to the order of the charging gun connection, and marks the initial charging state. If the pre-check fails, a fault alarm is given.

[0075] II. Charging start control

[0076] When charging starts, a hierarchical activation strategy is executed: the VCU 1 preferentially controls the BMS of the first battery pack (denoted as BMS A) to connect the high-voltage loop, and sequentially closes the corresponding contacts in the PDU in the order of “negative contactor→positive contactor”, while sending an activation instruction to the DCDC 4, so that the BMS A enters the formal charging state. While the BMS A starts charging, the BMSs of the remaining battery packs (i.e. BMS B to BMS N) synchronously complete the high-voltage loop connection operation, realizing the start of parallel charging of multiple groups. Each BMS continuously monitors three types of key event signals during the charging process: charging completion feedback, user gun pulling trigger signal, and high-voltage shutdown request instruction, and uploads them to the VCU 1 in real time.

[0077] III. Dynamic running state processing

[0078] For different running states in the charging process, the system executes differentiated control strategies:

[0079] (1) BMS A full charging after part of the battery pack 2 is not full: when BMS A completes charging first and other BMSs are still in the charging state, VCU 1 immediately sends a disable instruction to DCDC 4, and simultaneously performs a high-voltage operation on the PDU auxiliary circuit. After DCDC 4 is completely powered off, control BMS A to disconnect the positive and negative contactors to exit the high-voltage state; then sequentially close the corresponding negative and positive contactors of BMS B to reactivate DCDC 4 to ensure that the remaining battery packs (BMS B to BMS N) continue to charge. At the same time, the system reorders the remaining battery packs, marks the original BMS B as the new BMS A and assigns it a "non-first charging" state, and continues to monitor its charging process.

[0080] (2) BMS A full charging after the whole is completed or not started: if BMS A is charged when the other battery packs are in the charging completion or non-starting state, VCU 1 performs a closed-loop power-off process: sequentially sends a DCDC 4 shutdown instruction, a PDU auxiliary circuit low-voltage signal, and a BMS A high-voltage disconnection instruction, and finally completes the vehicle power-off operation.

[0081] (3) BMS A interrupts charging in the middle: when BMS A detects a gun pulling signal or receives a low-voltage request in the non-full state, and other BMSs are still charging, the system automatically triggers an emergency switching mechanism, and performs contactor switching and DCDC 4 restart operation according to the BMS A full charging switching process in step (1) above, to ensure that the remaining battery packs are not affected.

[0082] (4) BMS A full charging after re-plugging: when the battery pack that has completed charging and is powered off is re-plugged, it will be connected to the charging sequence as a new BMS N and marked as "non-first charging". The system detects the A+ signal after plugging for 1 minute, and sends a high-voltage connection instruction by VCU 1 to restore the charging process of the battery pack.

[0083] (5) BMS A is not full, and other groups change state: when BMS A is in the non-full state, and BMS B to BMS N appear charging completion, gun pulling in the middle or request low-voltage, etc. The corresponding battery pack automatically performs power-off operation, disconnects the positive and negative contactors, and waits for re-plugging activation or vehicle shutdown.

[0084] The multi-battery pack charging management system of the application ensures charging safety through a double-core mechanism:

[0085] First, the contactor interlocking logic is designed to strictly prohibit the simultaneous attraction of the positive and negative contactors of different BMSs, thereby fundamentally avoiding the mutual charging risk between battery packs due to voltage differences;

[0086] Secondly, the "non-first charging" flag is introduced to realize double protection, which prevents the full battery pack from entering the dead cycle of "high voltage on-full battery detection-high voltage off-renewed high voltage on", and simplifies the process judgment by using the contactor state of the battery pack during switching, and eliminates the control logic blind area. The battery pack marked as non-first charging needs to pass 60-second delay detection, and only after confirming the stable plug-in signal can it trigger the high voltage on process again, forming a complete safety control closed loop.

[0087] Embodiment 3

[0088] The application also provides an engineering machine on which the multi-battery pack charging management system is installed. Specifically, the engineering machine is an electric excavator. From the perspective of charging management accuracy, the electric excavator has high working intensity and the battery is used frequently, and the multi-battery pack charging management system can dynamically adjust the charging strategy according to the real-time state of each battery, such as voltage, temperature, state of charge, etc. For example, when the temperature of a certain battery is too high, the system automatically reduces the charging current to prevent the battery from being damaged due to overheating, effectively prolonging the service life of the battery and reducing the high cost caused by battery replacement. In continuous operation scenarios such as mines, stable and reliable batteries can ensure that the excavator operates efficiently for a long time, avoid downtime caused by battery failure, and greatly improve work efficiency.

[0089] In terms of charging efficiency, the hierarchical logic control of the system realizes the parallel charging start of multiple battery packs. Taking a large electric excavator as an example, it is usually equipped with multiple large-capacity batteries, and the traditional charging method takes a long time, while the system can make each battery pack enter the charging state at the same time, greatly shortening the overall charging time. For example, during the lunch break at the construction site, the battery can be quickly charged, allowing the excavator to quickly enter the afternoon work, improving the daily working time of the equipment and the progress of the project.

[0090] In terms of safety, the double core mechanism of the multi-battery pack charging management system provides protection for the operation of the electric excavator. The contactor interlocking logic eliminates the risk of mutual charging between battery packs due to voltage differences, which is particularly important in complex construction sites, avoiding safety accidents such as fires caused by electrical faults. The "non-first charging" flag prevents full battery packs from falling into an invalid cycle, reduces hardware wear and tear, simplifies control logic, eliminates potential safety hazards, and ensures the safety of operators and equipment.

[0091] In addition, the system also improves the applicability of the electric excavator. Whether in small projects in remote mountainous areas or large construction sites in urban construction, the multi-battery pack charging management system can flexibly cope with different charging environments and operation needs, ensuring the stable operation of the electric excavator and helping the engineering machinery industry move towards green, efficient and intelligent direction.

[0092] In addition, those skilled in the art will appreciate that the features of the various embodiments can be combined with each other, where appropriate, in order to form different embodiments of the application. For example, in the above embodiments, those skilled in the art will appreciate that the features can be used in combination, as appropriate, in order to address the technical problems addressed by the present application.

[0093] The above description is merely preferred embodiments of the present application, and it should be pointed out that those skilled in the art can make several improvements and modifications without departing from the technical principles of the present application, and these improvements and modifications should also be considered as falling within the protection scope of the present application.

Claims

1. A multi-battery pack charge management system, comprising: The application relates to a vehicle charging system, comprising: a VCU (1) configured to perform vehicle starting control, charging process logic scheduling, high-voltage component coordination management and abnormal state processing; a plurality of battery packs (2), each of which is internally provided with an independent BMS, the BMS being configured to monitor the running state of the battery pack (2) in real time, and each battery pack (2) supporting charging and battery replacement operations; a PDU relay (3) integrated with positive and negative contactors corresponding to each battery pack (2) and a PDU auxiliary loop contactor connected in series in a DCDC (4) high-voltage power supply loop, the positive and negative contactors being used for controlling the on-off of the high-voltage loop of the corresponding battery pack (2); a DCDC (4) configured to convert high-voltage direct current output by the battery pack (2) into low-voltage direct current, and the working state of the DCDC (4) being controlled by the VCU (1); a charging gun (5) provided with a mistaken insertion prevention mechanical structure and a safety locking function, which outputs an A+ wake-up signal after gun insertion is completed, and the A+ wake-up signal is transmitted to a BMS wake-up interface of the corresponding battery pack (2) and a wake-up input end of the VCU (1) respectively, so that the BMS and the VCU (1) are activated to enter a charging preparation state; the VCU (1) is connected with the BMS of the battery pack (2), the PDU relay (3) and the DCDC (4) through a CAN communication bus to realize real-time data interaction, and the VCU (1) is connected with the contactor coil of the PDU relay (3) and the enable end of the DCDC (4) through a hard-wire control loop; the battery pack (2) is connected with the positive and negative contactors of the PDU relay (3) through a high-voltage interface, and the charging gun (5) is connected with the charging port of the battery pack (2) through a charging interface.

2. A multi-battery pack charge management system as claimed in claim 1, wherein, the VCU (1) is configured to receive the A+ wake-up signal of the charging gun (5) through a hard-wire connection, receive state feedback signals of the BMS of the battery pack (2), the PDU relay (3) and the DCDC (4) through a CAN communication bus, and send on-off instructions to the contactor coil of the PDU relay (3) and send enable control instructions to the DCDC (4) based on the state feedback signals.

3. A multi-bank charge management system as claimed in claim 1, wherein, the BMS of the battery pack (2) is configured to monitor the running state in real time, and the running state includes single-cell voltage, total voltage, charging and discharging current, cell temperature and state of charge SOC; each battery pack (2) is connected with the positive and negative contactors of the PDU relay (3) through a high-voltage interface, and the output end of the positive and negative contactors is connected with a vehicle high-voltage bus to provide power output for the vehicle.

4. A multi-bank charge management system as claimed in claim 1, wherein, the coil control end of the positive and negative contactors in the PDU relay (3) is connected with the driving interface of the VCU (1) to receive the on-off instructions of the VCU (1); the contact state signal of the PDU auxiliary loop contactor is fed back to the VCU (1) through a signal line to realize real-time feedback of the high-voltage access state of the DCDC (4).

5. A multi-bank charge management system as claimed in claim 1, wherein, One end of the charging gun (5) is provided with a power supply interface matched with an external charging pile, and the other end is provided with a charging interface matched with a corresponding battery pack (2) charging port; after the gun insertion action is completed, the mechanical locking mechanism inside the charging gun (5) is triggered, and the charging cabinet synchronously activates the BMS and VCU (1) from the sleep state to the charging preparation state through the A+ wake-up signal output by the built-in signal line of the charging gun (5).

6. A multi-battery pack charge management method, characterized by, The multi-battery pack charging management system according to any one of claims 1-5, comprising the following steps: S1, charging initialization stage: connect each battery pack charging gun to the corresponding interface, wake up the VCU by inserting the gun, the VCU starts the system health pre-check process, sequentially detects that the vehicle has no three-level fault, the positive and negative electrode contactors in the power distribution unit have no adhesion, and the communication link between the BMS and the PDU and DCDC is unobstructed, and after the pre-check is passed, assigns a unique serial number to each BMS according to the charging gun connection order and marks the initial charging state; S2, charging start control stage: the VCU executes a hierarchical activation strategy, preferentially controls serial number BMS A to close the PDU contactor in the order of negative electrode contactor to positive electrode contactor, and simultaneously activates DCDC to make BMS A enter the charging state, the remaining BMSs synchronously complete the high-voltage loop connection to realize parallel charging, and each BMS uploads the charging completion, gun pulling, and high-voltage closing request signals to the VCU in real time; S3, dynamic running state processing stage: differentiated control is performed for different running states, including: When BMS A is fully charged and some battery packs are not fully charged, the VCU disables DCDC and disconnects the BMS A contactor, reactivates the remaining BMSs, and updates the serial number and non-first charging state; When BMS A is fully charged and the whole is completed or not started, the VCU sequentially executes DCDC shutdown, PDU auxiliary loop high-voltage lowering, and vehicle power-off operation; When BMS A interrupts charging in the middle and other BMSs are still charging, an emergency switching mechanism is triggered to ensure the charging of the remaining battery packs; when the battery pack that has completed charging is reinserted, it is connected as a new BMS and marked as "non-first charging", and after 1 minute of gun insertion, the A+ signal is detected to resume charging; When BMS A is not fully charged, the corresponding BMS automatically powers off and waits to be activated or is uniformly shut down.

7. A multi-bank charge management method according to claim 6, wherein, In the dynamic running state processing stage, when BMS A is fully charged and some battery packs are not fully charged, the following sub-steps are included: The VCU sends a disable instruction to DCDC and performs a high-voltage lowering operation on the PDU auxiliary loop; after DCDC is completely powered off, the BMS A positive and negative electrode contactors are disconnected to exit the high-voltage state; the BMS B corresponding negative and positive electrode contactors are sequentially closed, and DCDC is reactivated to ensure continuous charging of the remaining battery packs; The remaining battery packs are reordered, the original BMS B is marked as a new BMS A and is given a "non-first charging" state.

8. The multi-bank charge management method of claim 6, wherein, It also includes a contactor interlocking safety control step: to prohibit the simultaneous attraction of the positive and negative electrode contactors of different BMSs, when it is detected that the contactor of a certain BMS is in a closed state, the VCU locks the contactor drive signals of other BMSs until the contactor of the BMS is completely disconnected, thereby avoiding the risk of mutual charging between battery packs due to voltage differences.

9. The multi-bank charge management method of claim 6, wherein, The system further comprises a "non-first charging" state management step: marking the "non-first charging" state for the battery pack re-accessing the charging sequence or completing the switching; after a 60-second delay detection after the marking, confirming that the plug-in signal is stable and has no abnormalities, the VCU allows the high-voltage connection process of the battery pack to be re-triggered, preventing the full battery pack from entering the charging dead loop and eliminating the control logic blind area.

10. A working machine, characterized in that The construction machinery is provided with the multi-battery pack charging management system according to any one of claims 1-5.

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