A multi-branch parallel power battery high-voltage system intelligent protection control system and method

Abstract

This invention discloses an intelligent protection control system and method for a multi-branch parallel power battery high-voltage system, comprising: multiple battery branches; a BDU high-voltage distribution unit connected to the multiple battery branches, with a current sampling unit and an intelligent fuse connected in series on each battery branch; a battery management system (BMS) connected to the BDU high-voltage distribution unit and each battery branch, the BMS being configured with a high-speed sampling unit, a storage unit, and a functional logic module; the high-speed sampling unit is used for high-frequency acquisition of bus voltage and current in each branch; the storage unit pre-stores fault discrimination thresholds, protection reference current parameters, and a multi-dimensional correction coefficient mapping table; the functional logic module includes a three-dimensional parameter fault discrimination module, an adaptive threshold correction module, and a multi-branch collaborative anti-chaining failure module. This invention can reduce the false protection rate, improve operating condition adaptability, and has fault isolation and anti-chaining failure capabilities.

Description

Technical Field

[0001] This invention relates to an intelligent protection control system and method for a multi-branch parallel power battery high-voltage system, belonging to the field of high-voltage safety protection technology for new energy vehicle batteries. Background Technology

[0002] Currently, the power battery systems of new energy commercial vehicles and construction machinery equipment mostly adopt a multi-branch parallel high-voltage power distribution architecture, relying on the parallel connection of multiple battery branches to improve the system output power and continuous load-carrying capacity. The battery high-voltage distribution box (BDU) is equipped with fuses and high-voltage relays to realize the on-off control of the high-voltage circuit and short-circuit fault protection.

[0003] Most existing high-voltage protection schemes rely on a single electrical quantity to determine faults. Traditional fuses identify faults based on a single current threshold or a single current change rate, making it difficult to distinguish between instantaneous high-current surges and actual short-circuit faults. High-amplitude surge currents are generated when the system is powered on or a load is connected, with a large current rise rate, which can easily cause fuses to blow falsely. This can lead to a sudden high-voltage shutdown of the vehicle, work interruption, and reduced reliability of the entire equipment.

[0004] Meanwhile, existing protection thresholds are all factory-preset fixed parameters, which cannot adapt to the characteristic evolution of the battery throughout its entire life cycle. Battery SOC, ambient temperature, and the number of charge-discharge cycles will all cause changes in battery internal resistance and ultimate short-circuit output current. Fixed protection thresholds will cause lag in protection action under low temperature and battery aging conditions, posing a risk of burning out high-voltage components; while under high temperature and fully charged conditions, the protection thresholds will be too sensitive, easily causing unnecessary false protection actions.

[0005] Furthermore, the multi-branch parallel power distribution architecture also poses a safety hazard of fault propagation. When a short circuit occurs in one branch and the fuse blows, the load current of the original faulty branch will be instantly reconfigured to the remaining intact branches, causing a step surge in the current of the remaining branches. Currently, the protection logic of each branch is independent, and there is no inter-branch linkage protection mechanism, which can easily induce multiple branches to overload and blow one after another, further leading to system cascading failures, BDU burnout, or even high-voltage fires and other serious safety accidents. Summary of the Invention

[0006] To address the problems existing in the prior art, this invention provides an intelligent protection control system and method for a multi-branch parallel power battery high-voltage system, which can reduce the false protection rate, improve the adaptability to operating conditions, and has the ability to isolate faults and prevent cascading failures.

[0007] To achieve the above objectives, the present invention employs an intelligent protection and control system for a multi-branch parallel power battery high-voltage system, comprising:

[0008] Multiple battery branches are connected in parallel to form a high-voltage parallel power distribution circuit for the power battery.

[0009] The BDU high-voltage power distribution unit is connected to the multiple battery branches and is used to realize the high-voltage power distribution of the whole vehicle and the on / off control of the high-voltage circuit. Each battery branch is equipped with a current sampling unit and a smart fuse connected in series.

[0010] The battery management system (BMS) is connected to the high-voltage power distribution unit (BDU) and each battery branch. The BMS is equipped with a high-speed sampling unit, a storage unit, and a functional logic module.

[0011] The high-speed sampling unit is used to collect the bus voltage and the current of each branch at high frequency, and to calculate the current change rate di / dt, the voltage change rate dV / dt and the duration of the abnormality in real time.

[0012] The storage unit pre-stores fault discrimination thresholds, protection reference current parameters, and a multi-dimensional correction coefficient mapping table.

[0013] The functional logic module includes a three-dimensional parameter fault discrimination module, an adaptive threshold correction module, and a multi-branch collaborative anti-chain failure module.

[0014] The three-dimensional parameter fault discrimination module is used to combine three sets of parameters—current change rate, voltage change rate, and abnormal duration—to jointly determine the fault type, distinguish between transient disturbances, suspected boundary anomalies, and actual short-circuit faults, and execute corresponding protection strategies.

[0015] The adaptive threshold correction module is used to dynamically and iteratively update the high-voltage protection threshold based on the real-time battery status parameters, thereby achieving adaptive protection of the battery.

[0016] The multi-branch collaborative anti-chain failure module is used to identify the current step impact risk of the remaining intact branches after a single branch fails and blows, and to execute a multi-level collaborative protection strategy to suppress the chain propagation of the fault.

[0017] The intelligent fuse has a dual protection mode: active triggering of the battery management system (BMS) and passive short-circuit fuse. The passive short-circuit fuse is used as a fallback protection under abnormal communication sampling conditions.

[0018] As an improvement, the three-dimensional parameter fault discrimination module is pre-configured with multiple sets of calibration thresholds, including instantaneous disturbance current change rate threshold, short-circuit fault current change rate threshold, short-circuit voltage drop threshold, disturbance duration threshold, and fault confirmation duration threshold.

[0019] The discrimination logic of the three-dimensional parameter fault discrimination module includes:

[0020] When the rate of change of current, the rate of change of voltage, and the duration of abnormality meet the preset transient disturbance conditions, it is determined to be a current impulse disturbance, and the fuse protection is prohibited from being triggered. Only the warning information is recorded and reported.

[0021] When the rate of change of current, the rate of change of voltage, and the duration of the abnormality meet the preset boundary conditions for suspected abnormality, the power reduction and current limiting protection is implemented, and the fault observation window duration is extended.

[0022] When the rate of change of current, rate of change of voltage, and duration of abnormality meet the preset short-circuit fault conditions, it is determined to be a real short-circuit fault, triggering the intelligent fuse of the corresponding branch to actively blow and isolate the faulty branch.

[0023] As an improvement, the transient disturbance conditions are specifically: 15A / ms < di / dt < 50A / ms, |dV / dt| < 2V / ms, and the abnormal duration t < 2ms;

[0024] The specific boundary suspected anomaly conditions are: di / dt > 50A / ms, |dV / dt| < 8V / ms, and 2ms ≤ t ≤ 3ms.

[0025] The specific short-circuit fault conditions are: di / dt > 50A / ms, dV / dt ≤ -8V / ms, and t > 3ms.

[0026] As an improvement, the adaptive threshold correction module is configured with a SOC correction coefficient, a temperature correction coefficient, and a cycle aging correction coefficient. The adaptive threshold correction module calculates the dynamic protection current threshold in real time based on a preset protection reference current through multi-coefficient product operation.

[0027] The battery management system (BMS) periodically reads and refreshes the battery status parameters every 100ms, and iteratively updates the dynamic protection current threshold.

[0028] As an improvement, the SOC correction coefficient is configured differently according to the battery SOC range: when SOC > 80%, KSOC is 0.85~0.95; when 30% ≤ SOC ≤ 80%, KSOC is 1.0; when SOC < 30%, KSOC is 1.0~1.15.

[0029] The temperature correction coefficient is configured differently according to the ambient temperature range: when the ambient temperature T < -10℃, KT is 0.80~0.95; when -10℃ ≤ T ≤ 55℃, KT is 1.0; when T > 55℃, KT is 0.80~0.95.

[0030] The cycle aging correction coefficient is configured differently according to the number of battery charge and discharge cycles: when the number of cycles N < 1000, the value of KN is 1.0; when 1000 ≤ N < 4000, the value of KN is 0.9~0.95; when N ≥ 4000, the value of KN is 0.8~0.9.

[0031] As an improvement, the multi-branch collaborative anti-chain failure module executes a three-level collaborative protection strategy after detecting that the faulty branch has blown and the remaining intact branch has a current step impact. The three-level collaborative protection strategy includes vehicle-wide load reduction, temporary enhancement of the protection sensitivity of intact branches, and graded handling of fault observation windows.

[0032] As an improvement, the multi-branch collaborative anti-chain failure module sets 30A / ms as the branch current step impact judgment threshold, opens a 10ms fault observation window, and temporarily lowers the dynamic protection current threshold of the intact branch by 20% within the fault observation window;

[0033] The specific tiered handling logic is as follows: if the branch current exceeds the threshold within the observation window, the corresponding branch will be immediately melted and isolated; if the branch current falls back to the safe range, the control system will be degraded; if multiple branches continue to show abnormalities, the main relay will be disconnected to achieve high-voltage power-off of the entire vehicle.

[0034] As an improvement, the BDU high-voltage power distribution unit also integrates a charging circuit, a discharging circuit, a battery heating circuit, and a vehicle auxiliary drive circuit. The charging circuit, battery heating circuit, and vehicle auxiliary drive circuit are all equipped with conventional fuses for passive protection. The discharging circuit is used to supply power to the vehicle load equipment.

[0035] The battery management system (BMS) uploads the fault branch number, fault electrical parameters, and fuse type to the outside world via the CAN bus, completing fault data archiving and vehicle fault prompts.

[0036] A second aspect of the present invention also provides an intelligent protection and control method for a multi-branch parallel power battery high-voltage system, applied to the aforementioned control system, comprising the following steps:

[0037] S1. During normal system operation, the battery management system (BMS) collects the bus voltage and the current of each parallel battery branch at a preset high-frequency cycle, and calculates the current change rate, voltage change rate and abnormal duration in real time.

[0038] S2. Based on the three-dimensional parameters of current change rate, voltage change rate, and abnormal duration, the fault type is jointly determined, and differentiated protection logic is executed for transient disturbances, suspected boundary anomalies, and actual short-circuit faults.

[0039] S3. The Battery Management System (BMS) periodically collects battery SOC, ambient temperature, and charge / discharge cycle count, and dynamically updates the high-voltage protection threshold through multi-dimensional correction coefficients.

[0040] S4. Real-time monitoring of the operating status of each battery branch; after a single branch fails and blows, the faulty branch is locked; the current step impact risk of the remaining intact branches is identified; and a multi-level collaborative anti-interlock protection mechanism is activated.

[0041] S5. After the fault event is handled, upload complete fault data; when the sampling communication is abnormal, the passive fuse mode of the smart fuse is used to achieve backup safety protection.

[0042] As an improvement, in step S4, the execution flow of the multi-level collaborative anti-chain protection mechanism is as follows:

[0043] Prioritize issuing a full-vehicle load reduction command to weaken the system's impact load, open a short-term fault observation window and temporarily lower the protection threshold to improve fault response sensitivity, and complete graded fault handling based on the branch current status within the fault observation window to prevent the chain propagation of multiple branch faults.

[0044] Compared with the prior art, the beneficial effects of the present invention are:

[0045] (1) This invention relies on a high-speed sampling unit, a storage unit, a three-dimensional parameter fault discrimination module, an adaptive threshold correction module, and a multi-branch collaborative anti-chain failure module, combined with an intelligent fuse with dual protection modes of active triggering and passive short-circuit fuse, to achieve hardware and software collaborative protection. The intelligent fuse, in conjunction with the sampling unit and the battery management system (BMS), can complete fault response based on preset protection strategies or external signals. It has a fast fault identification response speed and high protection accuracy, and can distinguish between normal impacts and real short-circuit faults caused by fast charging and other operating conditions, reducing the risk of false protection. It can also achieve active disconnection according to control commands, and has fault self-diagnosis and communication reporting capabilities, which facilitates fault tracing and helps reduce equipment maintenance costs.

[0046] (2) The present invention adopts a three-dimensional parameter combined fault discrimination mode of current change rate, voltage change rate and abnormal duration to overcome the shortcomings of single electrical quantity discrimination. It can effectively distinguish between transient disturbances and real short circuit faults, reduce the false operation of smart fuses, reduce the probability of high voltage stop and operation interruption of the whole vehicle, and improve the operational reliability of the high voltage system of multi-branch parallel power battery.

[0047] (3) The present invention sets up a multi-dimensional adaptive threshold correction mechanism, which uses SOC correction coefficient, temperature correction coefficient and cycle aging correction coefficient to dynamically update the high voltage protection threshold, so that the protection characteristics can adapt to the state changes of the battery throughout the entire life cycle, the entire temperature range and the entire charge range, and improve the problem of protection lag or false protection caused by the fixed protection threshold being unable to take into account different battery states.

[0048] (4) The present invention is configured with a multi-branch collaborative anti-chain failure module. After the single-branch smart fuse blows, it identifies the current step impact risk of the remaining intact branches and implements a multi-level collaborative protection strategy of full-domain load reduction of the whole vehicle, temporary enhancement of the protection sensitivity of intact branches, and graded handling to suppress fault propagation, alleviate the chain burn-out problem caused by current reconstruction after a single branch failure in the multi-branch parallel system, reduce the risk of multi-branch chain failure, and improve the safety and fault tolerance of the multi-branch parallel high-voltage power distribution system. Attached Figure Description

[0049] Figure 1 This is a schematic diagram of the overall structure of the intelligent protection and control system for the multi-branch parallel power battery high-voltage system of the present invention.

[0050] Figure 2 This is a flowchart of the fault discrimination logic of the three-dimensional parameter fault discrimination module of the present invention;

[0051] Figure 3 This is the short-circuit protection time-current curve of the present invention;

[0052] Figure 4 This is a flowchart of the dynamic protection threshold update process of the adaptive threshold correction module of the present invention;

[0053] Figure 5 This is a flowchart of the multi-level collaborative protection strategy of the multi-branch collaborative anti-chain failure module of the present invention. Detailed Implementation

[0054] The technical solution of the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the embodiments and specific features in the embodiments are detailed descriptions of the technical solution of the present application, rather than limitations thereof. In the absence of conflict, the embodiments and technical features in the embodiments can be combined with each other.

[0055] Example 1

[0056] This embodiment provides an intelligent protection and control system for a multi-branch parallel power battery high-voltage system, applicable to the multi-branch parallel BDU high-voltage power distribution architecture of new energy commercial vehicles and construction machinery. The system supports up to five battery branches in parallel output. Addressing the structural defects of traditional high-voltage protection schemes, which employ single protection criteria, fixed protection thresholds, and independent branch protection without linkage, this invention optimizes the BDU multi-branch parallel hardware topology, branch independent sampling and fuse architecture, and BMS modular functional architecture. Combined with a three-dimensional parameter joint fault discrimination mechanism, a multi-dimensional adaptive threshold correction mechanism, and a multi-branch collaborative anti-chain failure strategy, it achieves collaborative optimization at both the hardware architecture and software control levels. This effectively solves the problems of high false protection rate, poor adaptability to all life-cycle operating conditions, easy chain failure of multiple branches due to single-branch faults, and low system protection fault tolerance in traditional schemes, significantly improving the operational stability and high-voltage safety redundancy of multi-branch parallel power battery high-voltage systems.

[0057] like Figure 1 As shown, the control system of this invention includes multiple battery branches, a BDU high-voltage power distribution unit, and a battery management system (BMS). The multiple battery branches are connected in parallel to form a high-voltage parallel power distribution circuit for the power battery. Relying on the multi-branch current-sharing structure, the overall output power and continuous load-carrying capacity of the system are effectively improved to meet the high-power operating conditions of commercial vehicles and construction machinery. The BDU high-voltage power distribution unit is electrically connected to the multiple battery branches to realize the high-voltage power distribution of the whole vehicle and the on / off control of the high-voltage circuit. Each battery branch is independently connected in series with a current sampling unit and a Pyrofuse intelligent fuse to realize independent acquisition of electrical parameters of a single branch and independent fault isolation, overcoming the shortcomings of inaccurate fault location and fast fault propagation speed of traditional centralized protection structures.

[0058] The battery management system (BMS) establishes electrical and signal connections with the high-voltage power distribution unit (BDU) and each battery branch. The BMS adopts a modular functional design and is specifically configured with a high-speed sampling unit, a storage unit, and a functional logic module. The overall layering is clear, the functions are independent and coordinated and controllable, providing hardware support for high-voltage fault identification, dynamic threshold control, and multi-branch collaborative protection.

[0059] The high-speed sampling unit collects the bus voltage and the current of each branch at a high-frequency sampling period of 0.5ms, and calculates the current change rate di / dt, voltage change rate dV / dt and abnormal duration in real time. The high-frequency real-time sampling ensures that the fault characteristic parameters are captured without delay, providing raw data support for fault identification.

[0060] The storage unit pre-stores fault discrimination thresholds, protection reference current parameters, and a multi-dimensional correction coefficient mapping table, which enables rapid retrieval and matching of operating parameters and protection thresholds.

[0061] The functional logic module specifically includes a three-dimensional parameter fault discrimination module, an adaptive threshold correction module, and a multi-branch collaborative anti-chain failure module. The modular structure design enables the fault discrimination, threshold correction, and chain protection functions to operate independently and work together, with clear control logic hierarchy and high response efficiency.

[0062] The intelligent fuse has a dual protection mode: active fuse triggered by the battery management system (BMS) and passive short-circuit fuse. The passive short-circuit fuse is used as a fallback protection under abnormal communication sampling conditions. The dual-mode fuse structure constructs a dual hardware and software safety protection system, which makes up for the shortcomings of traditional single passive fuse structure in terms of protection lag and lack of active intervention capability.

[0063] In some embodiments, the three-dimensional parameter fault discrimination module is pre-configured with multiple sets of calibration thresholds, specifically including the instantaneous disturbance current change rate threshold, the short-circuit fault current change rate threshold, the short-circuit voltage drop threshold, the disturbance duration threshold, and the fault confirmation duration threshold. Traditional high-voltage protection structures rely solely on a single current parameter for fault determination, with simple hardware sampling and discrimination logic, failing to distinguish between operational shocks and actual faults. This invention, based on a hardware structure with multi-channel independent high-speed sampling, abandons the traditional single electrical quantity fault judgment method and adopts a three-dimensional parameter joint discrimination logic of current change rate, voltage change rate, and abnormal duration. This accurately distinguishes transient disturbances, suspected boundary anomalies, and actual short-circuit faults, and executes corresponding protection strategies, avoiding misjudgments and missed judgments caused by single-parameter discrimination at the hardware sampling level.

[0064] The specific judgment conditions are as follows: When 15A / ms < di / dt < 50A / ms, |dV / dt| < 2V / ms, and the abnormal duration t < 2ms are met, it is judged as a current surge disturbance, and the fuse protection is prohibited from being triggered. Only the warning information is recorded and reported, and the high-voltage circuit is kept in normal conduction. When di / dt > 50A / ms, |dV / dt| < 8V / ms, and 2ms ≤ t ≤ 3ms are met, it is judged as a suspected boundary anomaly. The system performs power reduction and current limiting protection and extends the fault observation window duration to avoid false protection under boundary conditions. When di / dt > 50A / ms, dV / dt ≤ -8V / ms, and t > 3ms are met, it is judged as a real short-circuit fault. The corresponding branch's smart fuse is immediately triggered to actively blow, isolating the faulty branch. The complete judgment process is as follows: Figure 2 As shown, based on the independent sampling of each branch and the linkage and discrimination structure of the whole domain parameters, it is possible to accurately locate and isolate faults in a single branch without affecting the normal operation of other intact branches.

[0065] In some embodiments, the adaptive threshold correction module is configured with a SOC correction coefficient (KSOC), a temperature correction coefficient (KT), and a cycle aging correction coefficient (KN). Based on the reference protection currents IA0 and IB0 calibrated at room temperature, 50% SOC, and a brand-new cell state, the dynamic protection current threshold is calculated in real time using the multi-coefficient product formulas IA=IA0×KSOC×KT×KN and IB=IB0×KSOC×KT×KN. Traditional BDU protection thresholds are factory-fixed parameters, which cannot adapt to changes in battery SOC fluctuations, ambient temperature variations, and cell aging degradation, easily leading to problems such as protection lag under low-temperature aging conditions and excessive sensitivity under high-temperature full-charge conditions. This invention relies on a BMS full-domain operating condition monitoring architecture, periodically reading battery SOC, ambient temperature, and charge / discharge cycle count every 100ms, refreshing each correction coefficient in real time, and iteratively updating the dynamic protection threshold, so that the protection characteristics are adapted to the battery's entire life cycle, all temperature ranges, and all charge ranges in real time. Figure 4 .

[0066] The differentiated configuration rules for each correction coefficient in this embodiment are as follows:

[0067] SOC Correction Rules: When SOC > 80%, the cell open-circuit voltage is high, and the energy released by the short circuit is greater. The system lowers the protection threshold, taking KSOC = 0.85~0.95; when 30% ≤ SOC ≤ 80%, it is a medium charge range, and the benchmark threshold is adopted, taking KSOC = 1.0; when SOC < 30%, the remaining charge is low, and the energy released by the short circuit is small. The protection current threshold can be appropriately relaxed, taking KSOC = 1.0~1.15.

[0068] Ambient temperature correction rules: In low-temperature conditions T < -10℃, the cell internal resistance increases, and the heating under the same short-circuit current intensifies, so the A / B current threshold is reduced, and KT = 0.80~0.95 is taken; when the temperature is -10℃ ≤ T ≤ 55℃, the battery system is in the normal operating temperature range, and KT = 1.0 is taken; when the temperature is T > 55℃, it is a high-temperature condition, the cell heat resistance decreases, and the risk of thermal runaway increases, so the boundary current threshold is lowered, and KT = 0.80~0.95 is taken.

[0069] Cyclic aging correction rules: N < 1000 cycles, brand new cell, KN = 1.0; 1000 ≤ N < 4000, mild aging, cell internal resistance slightly increased, threshold reduced by 5%~10%, KN = 0.9~0.95; N ≥ 4000, severe aging, cell severely deteriorated, short circuit withstand capability significantly reduced, threshold reduced by 10%~20%, KN = 0.8~0.9.

[0070] The BMS periodically reads the battery SOC, temperature, and cell cycle count (refreshed every 100ms), calculates and updates the current protection thresholds at intersection points A and B in real time, and dynamically switches the current limiting protection of the relays and the trigger boundaries for the active melting of the Pyrofuse smart fuse, ensuring that the protection action points are matched in real time with the battery's current charge, ambient temperature, and aging degradation status. Additionally, as... Figure 3 As shown, intersection points A and B in the matching curves of the smart fuse and relay are the static calibration current points. In this embodiment, intersection points A and B are set as dynamic adaptive current thresholds, which are corrected in real time based on three factors: battery SOC, ambient temperature T, and battery cumulative cycle count N, outputting dynamic intersection points IA and IB. The BMS updates the correction coefficients KSOC, KT, and KN every 100ms, and refreshes the dynamic protection thresholds using the formulas IA=IA0×KSOC×KT×KN and IB=IB0×KSOC×KT×KN, so that the protection characteristics match the current operating conditions and aging status of the battery in real time.

[0071] In some embodiments, the multi-branch collaborative anti-cascading failure module is used to suppress the risk of fault propagation in a multi-branch parallel architecture. In traditional multi-branch parallel BDU structures, each branch is independent and lacks a linkage protection mechanism. The reconfiguration of a single branch fault current can easily trigger a cascading burnout of multiple branches, posing a significant structural safety hazard. This invention, based on a hardware architecture for multi-branch linkage monitoring, executes a three-level collaborative protection strategy when a single branch smart fuse blows and the remaining intact branches experience a current step surge. For example... Figure 5 As shown, this invention sets 30A / ms as the threshold for determining branch current step surges to identify fault transfer surge risks.

[0072] Level 1 Global Load Reduction: Millisecond-level power limiting command is issued for the entire vehicle to reduce the total system current and weaken the impact load from the source;

[0073] Level 2 high-sensitivity observation: Open a dedicated 10ms fault observation window and temporarily lower the dynamic IA and IB thresholds of intact branches by 20% to improve the sensitivity of instantaneous fault response.

[0074] Level 3 tiered handling: If the branch current within the observation window exceeds the IB threshold, the fuse will be immediately tripped for isolation; if the current drops, the system will be degraded; if multiple circuits are continuously abnormal, the main relay will be disconnected and the entire vehicle will be powered down.

[0075] After a fault occurs, the system locks the faulty branch and uploads complete fault data via the CAN bus, achieving fault isolation, risk suppression, and traceable diagnosis.

[0076] Failure fallback protection: When the branch current sampling signal experiences a communication delay and the BMS fails to detect a sudden increase in branch current in time, the Pyrofuse smart fuses in the remaining healthy branches rely on the passive short-circuit fuse protection curve as the last line of defense to prevent cascading burnout.

[0077] In some embodiments, the BDU high-voltage power distribution unit of the present invention also integrates a charging circuit, a discharging circuit, a battery heating circuit, and a vehicle auxiliary drive circuit, forming a multi-circuit integrated high-voltage power distribution structure with high integration and compact layout, adapting to the high-voltage assembly requirements of the vehicle. The charging circuit, battery heating circuit, and vehicle auxiliary drive circuit are all equipped with conventional fuses for passive protection. The discharging circuit supplies power to the vehicle's load equipment. Different circuits employ differentiated protection structures, balancing the stability of conventional circuit protection with the precise and intelligent protection requirements of the power circuit. The Battery Management System (BMS) can upload fault branch numbers, fault electrical parameters, and fuse types to the outside via the CAN bus, completing fault data archiving and vehicle fault prompts, facilitating fault tracing and equipment maintenance, and improving the system's intelligent operation and maintenance capabilities.

[0078] Example 2

[0079] A method for intelligent protection and control of a multi-branch parallel high-voltage power battery system, applied to the intelligent protection and control system of the multi-branch parallel high-voltage power battery system described in Embodiment 1 above, includes the following steps:

[0080] S1. During normal system operation, the battery management system (BMS) collects the bus voltage and the current of each parallel battery branch at a preset high-frequency cycle, and calculates the current change rate, voltage change rate and abnormal duration in real time.

[0081] S2. Based on the three-dimensional parameters of current change rate, voltage change rate, and abnormal duration, the fault type is jointly determined, and transient disturbances, suspected boundary anomalies, and real short-circuit faults are distinguished. Differentiated protection logic is executed for different fault types.

[0082] S3. The Battery Management System (BMS) periodically collects battery SOC, ambient temperature, and charge / discharge cycle count. Through a multi-dimensional correction model using SOC correction coefficient, temperature correction coefficient, and cycle aging correction coefficient, it dynamically updates the high-voltage protection threshold of each branch.

[0083] S4. Real-time monitoring of the operating status of each battery branch; after a single branch fails and blows, the faulty branch is locked; the current step impact risk of the remaining intact branches is identified; and a multi-level collaborative anti-interlock protection mechanism is activated.

[0084] S5. After the fault event is handled, upload complete fault data; when the sampling communication is abnormal, the passive fuse mode of the smart fuse is used to achieve backup safety protection.

[0085] In some embodiments, the specific execution process of the multi-level collaborative anti-chain protection mechanism in step S4 is as follows: firstly issue a vehicle-wide load reduction command to weaken the system impact load, open a short-term fault observation window and temporarily lower the protection threshold of the intact branch to improve fault response sensitivity, complete graded fault handling according to the branch current status in the fault observation window, block the chain propagation of multi-branch faults from the source, and improve the operational safety and fault tolerance of the multi-branch parallel high voltage system.

[0086] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. An intelligent protection and control system for a multi-branch parallel power battery high-voltage system, characterized in that, include: Multiple battery branches are connected in parallel to form a high-voltage parallel power distribution circuit for the power battery. The BDU high-voltage power distribution unit is connected to the multiple battery branches and is used to realize the high-voltage power distribution of the whole vehicle and the on / off control of the high-voltage circuit. Each battery branch is equipped with a current sampling unit and a smart fuse connected in series. The battery management system (BMS) is connected to the high-voltage power distribution unit (BDU) and each battery branch. The BMS is equipped with a high-speed sampling unit, a storage unit, and a functional logic module. The high-speed sampling unit is used to collect the bus voltage and the current of each branch at high frequency, and to calculate the current change rate di / dt, the voltage change rate dV / dt and the duration of the abnormality in real time. The storage unit pre-stores fault discrimination thresholds, protection reference current parameters, and a multi-dimensional correction coefficient mapping table. The functional logic module includes a three-dimensional parameter fault discrimination module, an adaptive threshold correction module, and a multi-branch collaborative anti-chain failure module. The three-dimensional parameter fault discrimination module is used to combine three sets of parameters—current change rate, voltage change rate, and abnormal duration—to jointly determine the fault type, distinguish between transient disturbances, suspected boundary anomalies, and actual short-circuit faults, and execute corresponding protection strategies. The adaptive threshold correction module is used to dynamically and iteratively update the high-voltage protection threshold based on the real-time battery status parameters, thereby achieving adaptive protection of the battery. The multi-branch collaborative anti-chain failure module is used to identify the current step impact risk of the remaining intact branches after a single branch fails and blows, and to execute a multi-level collaborative protection strategy to suppress the chain propagation of the fault. The intelligent fuse has a dual protection mode: active triggering of the battery management system (BMS) and passive short-circuit fuse. The passive short-circuit fuse is used as a fallback protection under abnormal communication sampling conditions.

2. The intelligent protection and control system for a multi-branch parallel power battery high-voltage system according to claim 1, characterized in that, The three-dimensional parameter fault discrimination module is pre-configured with multiple sets of calibration thresholds, including instantaneous disturbance current change rate threshold, short-circuit fault current change rate threshold, short-circuit voltage drop threshold, disturbance duration threshold, and fault confirmation duration threshold. The discrimination logic of the three-dimensional parameter fault discrimination module includes: When the rate of change of current, the rate of change of voltage, and the duration of abnormality meet the preset transient disturbance conditions, it is determined to be a current impulse disturbance, and the fuse protection is prohibited from being triggered. Only the warning information is recorded and reported. When the rate of change of current, the rate of change of voltage, and the duration of the abnormality meet the preset boundary conditions for suspected abnormality, the power reduction and current limiting protection is implemented, and the fault observation window duration is extended. When the rate of change of current, rate of change of voltage, and duration of abnormality meet the preset short-circuit fault conditions, it is determined to be a real short-circuit fault, triggering the intelligent fuse of the corresponding branch to actively blow and isolate the faulty branch.

3. The intelligent protection and control system for a multi-branch parallel power battery high-voltage system according to claim 2, characterized in that, The transient disturbance conditions are specifically: 15A / ms < di / dt < 50A / ms, |dV / dt| < 2V / ms, and the duration of the abnormality t < 2ms. The specific boundary suspected anomaly conditions are: di / dt > 50A / ms, |dV / dt| < 8V / ms, and 2ms ≤ t ≤ 3ms. The specific short-circuit fault conditions are: di / dt > 50A / ms, dV / dt ≤ -8V / ms, and t > 3ms.

4. The intelligent protection and control system for a multi-branch parallel power battery high-voltage system according to claim 1, characterized in that, The adaptive threshold correction module is configured with a SOC correction coefficient, a temperature correction coefficient, and a cycle aging correction coefficient. The adaptive threshold correction module calculates the dynamic protection current threshold in real time based on a preset protection reference current through multi-coefficient product operation. The battery management system (BMS) periodically reads and refreshes the battery status parameters every 100ms, and iteratively updates the dynamic protection current threshold.

5. The intelligent protection and control system for a multi-branch parallel power battery high-voltage system according to claim 4, characterized in that, The SOC correction coefficient is configured differently according to the battery SOC range: when SOC > 80%, KSOC is 0.85~0.95; when 30% ≤ SOC ≤ 80%, KSOC is 1.0; when SOC < 30%, KSOC is 1.0~1.

15. The temperature correction coefficient is configured differently according to the ambient temperature range: when the ambient temperature T < -10℃, KT is 0.80~0.95; when -10℃ ≤ T ≤ 55℃, KT is 1.0; when T > 55℃, KT is 0.80~0.

95. The cycle aging correction coefficient is configured differently according to the number of battery charge and discharge cycles: when the number of cycles N < 1000, the value of KN is 1.0; when 1000 ≤ N < 4000, the value of KN is 0.9~0.95; when N ≥ 4000, the value of KN is 0.8~0.

9.

6. The intelligent protection and control system for a multi-branch parallel power battery high-voltage system according to claim 1, characterized in that, When the multi-branch collaborative anti-chain failure module detects that a faulty branch has blown and the remaining intact branches have experienced a current step impact, it executes a three-level collaborative protection strategy. The three-level collaborative protection strategy includes vehicle-wide load reduction, temporary enhancement of the protection sensitivity of intact branches, and graded handling of fault observation windows.

7. The intelligent protection and control system for a multi-branch parallel power battery high-voltage system according to claim 6, characterized in that, The multi-branch collaborative anti-chain failure module sets 30A / ms as the branch current step impact judgment threshold, opens a 10ms fault observation window, and temporarily lowers the dynamic protection current threshold of the intact branch by 20% within the fault observation window; The specific tiered handling logic is as follows: if the branch current exceeds the threshold within the observation window, the corresponding branch will be immediately melted and isolated; if the branch current falls back to the safe range, the control system will be degraded; if multiple branches continue to show abnormalities, the main relay will be disconnected to achieve high-voltage power-off of the entire vehicle.

8. The intelligent protection and control system for a multi-branch parallel power battery high-voltage system according to claim 1, characterized in that, The BDU high-voltage power distribution unit also integrates a charging circuit, a discharging circuit, a battery heating circuit, and a vehicle auxiliary drive circuit. The charging circuit, battery heating circuit, and vehicle auxiliary drive circuit are all equipped with conventional fuses for passive protection. The discharging circuit is used to supply power to the vehicle load equipment. The battery management system (BMS) uploads the fault branch number, fault electrical parameters, and fuse type to the outside world via the CAN bus, completing fault data archiving and vehicle fault prompts.

9. A method for intelligent protection and control of a multi-branch parallel power battery high-voltage system, characterized in that, The control system applied to any one of claims 1-8 includes the following steps: S1. During normal system operation, the battery management system (BMS) collects the bus voltage and the current of each parallel battery branch at a preset high-frequency cycle, and calculates the current change rate, voltage change rate and abnormal duration in real time. S2. Based on the three-dimensional parameters of current change rate, voltage change rate, and abnormal duration, the fault type is jointly determined, and differentiated protection logic is executed for transient disturbances, suspected boundary anomalies, and actual short-circuit faults. S3. The Battery Management System (BMS) periodically collects battery SOC, ambient temperature, and charge / discharge cycle count, and dynamically updates the high-voltage protection threshold through multi-dimensional correction coefficients. S4. Real-time monitoring of the operating status of each battery branch; after a single branch fails and blows, the faulty branch is locked; the current step impact risk of the remaining intact branches is identified; and a multi-level collaborative anti-interlock protection mechanism is activated. S5. After the fault event is handled, upload complete fault data; when the sampling communication is abnormal, the passive fuse mode of the smart fuse is used to achieve backup safety protection.

10. The intelligent protection and control method for a multi-branch parallel power battery high-voltage system according to claim 9, characterized in that, In step S4, the execution flow of the multi-level collaborative anti-chain protection mechanism is as follows: Prioritize issuing a full-vehicle load reduction command to weaken the system's impact load, open a short-term fault observation window and temporarily lower the protection threshold to improve fault response sensitivity, and complete graded fault handling based on the branch current status within the fault observation window to prevent the chain propagation of multiple branch faults.

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