Electric vehicle high-voltage battery out-of-control alarm system based on low-voltage battery

Abstract

The invention discloses an electric vehicle high-voltage battery out-of-control alarm system based on a low-voltage battery. According to the specific implementation scheme, a low-voltage battery BMS is used for cooperatively working with a high-voltage battery BMS and performing integrity and correctness verification on a received feedback signal; the signal processing unit is used for receiving and decompressing a state signal of the high-voltage battery BMS; the alarm logic unit is used for generating an alarm signal according to a processing result of the signal processing unit; the alarm execution unit is used for receiving the alarm signal, executing an alarm action and feeding back the alarm action to the feedback confirmation unit; the feedback confirmation unit is used for verifying the execution condition of the alarm action and sending a feedback signal to the low-voltage battery BMS; and the data recording unit is used for storing the alarm event and the system state data. According to the invention, the dependence of a high-voltage battery system and the dependence on a communication network can be effectively reduced, and the timeliness and reliability of alarm are effectively improved.

Description

Technical Field

[0001] The present invention relates to the technical field of electric vehicle battery safety monitoring, and particularly to an out-of-control alarm system for high-voltage batteries of electric vehicles based on low-voltage batteries. Background Art

[0002] With the rapid growth of the electric vehicle (EV) market, ensuring the safety of battery systems has become a crucial issue in the industry. Especially for the possible thermal runaway phenomenon of high-voltage battery systems, which may lead to serious safety accidents and pose a threat to passenger safety. Therefore, it is particularly important to develop a system that can give early warnings of thermal runaway. In existing technical solutions, a thermal runaway alarm system based on a battery management system and a vehicle control unit has been proposed. This system is implemented by monitoring key parameters such as temperature, pressure, current, and voltage inside the battery pack, and combining with a smoke sensor to monitor the smoke concentration inside the battery pack. It highly depends on the battery management system and the vehicle control unit that are closely integrated with the high-voltage battery system. When a serious fault occurs in the high-voltage battery system, these key components may not work properly, affecting the reliability of the entire alarm system; and due to the need to perform data analysis and transmission through multiple steps, the alarm triggering speed is slow, especially there may be delays during the data transmission process. In addition, the existing solutions have a strong dependence on the communication network. It is necessary to upload data to the cloud server through an in-vehicle terminal and receive the analysis results. In the case of unstable or interrupted network, it may affect the accuracy and reliability of the alarm system. Summary of the Invention

[0003] Based on this, in order to solve the problems of high dependence on the high-voltage battery system, slow alarm triggering speed, and strong dependence on the communication network in the existing technology, the present invention provides an out-of-control alarm system for high-voltage batteries of electric vehicles based on low-voltage batteries.

[0004] The present invention provides an out-of-control alarm system for high-voltage batteries of electric vehicles based on low-voltage batteries, including:

[0005] A low-voltage battery BMS, which is used to work in cooperation with the high-voltage battery BMS and verify the integrity and correctness of the received feedback signal;

[0006] A signal processing unit, which is responsible for receiving and decompressing the status signal of the high-voltage battery BMS;

[0007] An alarm logic unit, which is used to generate an alarm signal according to the processing result of the signal processing unit;

[0008] An alarm execution unit, which is used to receive the alarm signal, execute the alarm action, and feedback to the feedback confirmation unit;

[0009] A feedback confirmation unit is used to verify the execution of the alarm action, send a feedback signal to the low-voltage battery BMS, and verify the received feedback signal.

[0010] A data recording unit is used to store alarm events and system status data.

[0011] The low-voltage battery BMS and the high-voltage battery BMS achieve data exchange through a communication interface module.

[0012] The communication interface module uses a CAN bus as the communication interface, and the physical layer of the CAN bus uses twisted pair to transmit differential signals.

[0013] The status signals include battery voltage, current, temperature, charge status, and fault codes, and the alarm signals include alarm signals for indicating abnormalities in the high-voltage battery BMS.

[0014] The signal processing unit is centered on an STM32 series microcontroller, has multiple communication interfaces and powerful processing capabilities, and is responsible for receiving and decoding status signals from the high-voltage battery BMS; collects analog signals of battery voltage and current through an ADC module and converts them into digital signals, and at the same time uses a temperature sensor to obtain battery temperature data and determines whether there is an abnormality in the high-voltage battery BMS.

[0015] The determination of whether there is an abnormality in the high-voltage battery BMS includes

[0016] Comparing the real-time monitored voltage with a preset safe voltage threshold, and comparing the temperature data with a preset safe temperature threshold. If the real-time monitored voltage exceeds the preset safe voltage threshold continuously for 3 times or the temperature data exceeds the preset safe temperature threshold continuously for 3 times, it is determined that there is an abnormality in the high-voltage battery BMS, and the alarm logic unit is triggered.

[0017] Based on a threshold-based anomaly detection algorithm, when the signal processing unit determines that there is an abnormality in the high-voltage battery BMS, it immediately triggers an alarm, and judges the fault type according to the fault code sent by the identified high-voltage battery BMS, and sends an alarm instruction to the vehicle alarm system in a timely manner.

[0018] After receiving the alarm signal, the alarm execution unit starts the alarm action in a dual alarm mode of sound and vision to prompt the abnormality of the high-voltage battery BMS.

[0019] After the alarm execution unit completes the alarm action, the feedback confirmation unit sends a feedback signal to the low-voltage battery BMS to confirm whether the alarm action has been successfully executed; if the alarm action has been successfully executed, the feedback confirmation unit verifies the received feedback signal.

[0020] The data recording unit is used to record the occurrence time, type, duration of the alarm event, and the system status.

[0021] Beneficial effects: The present invention uses a low-voltage battery as an independent power source to trigger the alarm system, which is different from the traditional design that relies on the main battery system. When a serious fault or failure occurs in the high-voltage battery system, the low-voltage battery can still supply power stably, ensuring that the alarm system continues to work and sending out warning signals in a timely manner. This significantly reduces the dependence on the high-voltage battery system and greatly improves the safety performance of electric vehicles in extreme situations.

[0022] By directly integrating the signal processing unit and the alarm logic unit in the low-voltage battery BMS, the alarm triggering process is simplified. Without going through multiple components and data transmission links, the delay in data transmission and processing is reduced, enabling the alarm system to respond more quickly to the abnormal state of the high-voltage battery and gaining more valuable response time for users, effectively improving the timeliness and reliability of the alarm.

[0023] Data processing and alarm triggering are carried out locally, greatly reducing the dependence on the communication network. Different from the prior art that needs to transmit data to the cloud server through the vehicle-mounted terminal and receive the analysis results, the present invention can independently complete the alarm task relying on the local low-voltage battery BMS even in the case of weak or interrupted network signals, ensuring the stability and timeliness of the alarm function and avoiding alarm delays or failures caused by network problems.

[0024] It should be understood that the content described in this part is not intended to identify the key or important features of the embodiments of the present invention, nor is it used to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. Description of the Drawings

[0025] The drawings are used to better understand the solution and do not constitute a limitation to the present invention. Among them:

[0026] Figure 1 is the system structure diagram provided by the present invention. Detailed Embodiments

[0027] The following describes the exemplary embodiments of the present invention in conjunction with the drawings. Various details of the embodiments of the present invention are included to facilitate understanding, and they should be considered merely exemplary. Therefore, those of ordinary skill in the art should recognize that various changes and modifications can be made to the embodiments described herein without departing from the scope and spirit of the present invention. Similarly, for clarity and conciseness, the description of well-known functions and structures is omitted below.

[0028] As Figure 1 shown, the present invention provides an out-of-control alarm system for the high-voltage battery of an electric vehicle based on a low-voltage battery, including:

[0029] A low-voltage battery BMS is used to work in cooperation with a high-voltage battery BMS and verify the integrity and correctness of the received feedback signal;

[0030] A signal processing unit is responsible for receiving and decompressing the status signal of the high-voltage battery BMS;

[0031] An alarm logic unit is used to generate an alarm signal according to the processing result of the signal processing unit;

[0032] An alarm execution unit is used to receive the alarm signal, execute the alarm action, and feedback to the feedback confirmation unit;

[0033] A feedback confirmation unit is used to verify the execution situation of the alarm action and send a feedback signal to the low-voltage battery BMS;

[0034] A data recording unit is used to store alarm events and system status data.

[0035] Preferably, the low-voltage battery BMS is a 48V auxiliary battery BMS;

[0036] The low-voltage battery BMS and the high-voltage battery BMS realize data exchange through a communication interface module.

[0037] The communication interface module uses a CAN bus as the communication interface, and the physical layer of the CAN bus uses twisted pairs to transmit differential signals.

[0038] Using a CAN bus as the communication interface and twisted pairs helps to reduce electromagnetic interference. To prevent signal reflection and ensure the integrity of the signal, 90 to 120 ohm termination resistors are equipped at both ends of the CAN bus, effectively reducing signal reflection and noise interference. The twisted pairs and termination resistors are used to improve the stability and reliability of communication, avoid external interference and signal reflection problems, effectively improve the data transmission quality, and ensure the stable operation of the system.

[0039] The CAN controller selects the Infineon TC298 series that supports the ISO 11898 standard, and sets the baud rate to 500 kbps to ensure the reliability and real-time performance of data transmission and provide stable communication between the low-voltage battery BMS and the high-voltage battery BMS. By redefining the cooperation mechanism between the low-voltage battery system and the high-voltage battery BMS, the function integration is optimized.

[0040] The low-voltage battery independent power supply design solves the dependence on the high-voltage system in the traditional solution; the localized processing architecture integrates functions such as signal processing and alarm logic into a single BMS, shortening the response time; the redundant safety guarantee mechanism can still trigger an alarm when the high-voltage system fails.

[0041] The present invention takes the low-voltage battery BMS as the core, works in cooperation with the high-voltage battery BMS, and realizes data exchange through the communication interface module; the signal processing unit is responsible for receiving and decoding the high-voltage battery status signals, and the alarm logic unit generates alarm signals according to the signal processing results; the alarm execution unit executes the alarm actions, the feedback confirmation unit verifies the execution situation of the alarm actions, and the data recording unit stores the alarm events and system status data, ensuring that an alarm can be triggered in a timely and accurate manner when the high-voltage battery gets out of control, and guaranteeing the safety of electric vehicles.

[0042] The status signals include battery voltage, current, temperature, charge status, and fault codes, and the alarm signals include alarm signals for indicating abnormalities in the high-voltage battery BMS.

[0043] The communication protocol details the data frame structure and communication timing. Each frame of data consists of an 11-bit ID, an 8-bit data length, an 8-bit data field, a 15-bit check sequence, and a 2-bit inter-frame space, ensuring the accurate transmission and parsing of data, and providing a standardized basis for the signal processing unit to correctly understand the received signals.

[0044] The signal processing unit takes the STM32 series microcontroller as the core, has multiple communication interfaces and powerful processing capabilities, and is responsible for receiving and decoding the status signals from the high-voltage battery BMS; it collects the analog signals of the battery voltage and current through the ADC module and converts them into digital signals, and at the same time uses the temperature sensor to obtain the battery temperature data and determines whether there are abnormalities in the high-voltage battery BMS.

[0045] The judgment of whether there are abnormalities in the high-voltage battery BMS includes

[0046] Comparing the real-time monitored voltage with the preset safe voltage threshold, and comparing the temperature data with the preset safe temperature threshold. If the real-time monitored voltage exceeds the preset safe voltage threshold continuously for 3 times or the temperature data exceeds the preset safe temperature threshold continuously for 3 times, it is determined that there are abnormalities in the high-voltage battery BMS, and the alarm logic unit is triggered.

[0047] The signal definitions and processing logics are as follows: The signal types include digital signals and temperature data. The digital signals are generated by the ADC module of the STM32 microcontroller collecting the analog signals of the high-voltage battery voltage and current and performing analog-to-digital conversion. The sampling frequency is 1 kHz and the resolution is 12 bits. The temperature data is directly obtained through a digital temperature sensor, with an accuracy of ±0.5°C and a data update frequency of 100 ms / time. The abnormal state judgment method is to monitor the voltage and temperature data in real time and compare them with the preset safe thresholds. The preset voltage safe threshold is 550V ± 5%, and the preset temperature safe threshold is 55°C ± 2°C. If the voltage or temperature exceeds the threshold continuously for 3 sampling values, it is determined as an abnormal state, and the alarm logic unit is triggered.

[0048] The alarm logic unit is based on a threshold-based anomaly detection algorithm. When the signal processing unit determines that there is an anomaly in the high-voltage battery BMS, it immediately triggers an alarm and, based on the fault code sent by the identified high-voltage battery BMS, determines the fault type and promptly sends an alarm instruction to the vehicle alarm system.

[0049] By directly integrating the signal processing unit and the alarm logic unit into the low-voltage battery BMS, the alarm triggering process is simplified. The signal processing unit can quickly receive and decode the status signals from the high-voltage battery BMS and compare them with the preset safety thresholds; the alarm logic unit, based on the threshold-based anomaly detection algorithm, can immediately generate an alarm signal and send it to the vehicle alarm system when it detects that the voltage or temperature of the high-voltage battery exceeds the safety threshold. This process reduces the links of data transmission and processing, enabling the alarm system to respond more quickly to the abnormal state of the high-voltage battery, winning more precious response time for users, effectively improving the timeliness and reliability of the alarm, enabling the driver and passengers to take response measures earlier, such as parking for inspection or evacuating the vehicle, thus reducing the probability of accidents and the potential damage level.

[0050] The threshold detection algorithm adopts a dynamic monitoring mechanism, where the voltage data sampling interval is 100 ms and the temperature data sampling interval is 200 ms to ensure real-time performance. At the same time, a sliding window algorithm is adopted. When the real-time monitored voltage exceeds the preset safety voltage threshold continuously for 3 times or the temperature data exceeds the threshold continuously for 3 times (the time window is 1 second), an alarm is triggered to avoid false alarms caused by instantaneous interference. The fault code recognition logic is to receive the fault code sent by the high-voltage battery BMS (through the CAN protocol frame ID0x18FFA1A1, and the data field contains the fault type encoding) and execute corresponding measures according to the predefined fault mapping table. For example, the fault code 0x01 indicates an overvoltage fault, and the response action is to cut off the high-voltage circuit and activate the buzzer; the fault code 0x02 indicates an overtemperature fault, and the response action is to start the liquid cooling system and flash the warning light; the fault code 0x03 indicates insulation failure, and the response action is to trigger a vehicle-wide power-off and store the event.

[0051] After receiving the alarm signal, the alarm execution unit starts the alarm action through a dual-alarm method of sound and vision to prompt the abnormal situation of the high-voltage battery BMS.

[0052] The alarm actions include activating the buzzer to emit a sound alarm of at least 80 dB(A) and making the warning light flash at a frequency of 1 Hz.

[0053] Data processing and alarm triggering are performed locally, significantly reducing the dependence on the communication network. Different from the prior art that requires the vehicle-mounted terminal to transmit data to the cloud server and receive the analysis results, the present invention can independently complete the alarm task relying on the local low-voltage battery BMS even in the case of weak or interrupted network signals, ensuring the stability and timeliness of the alarm function, avoiding alarm delay or failure caused by network problems, enabling the alarm system to operate stably in various network environments, providing continuous and reliable safety monitoring for electric vehicles, enhancing the overall stability of the system, and reducing potential safety hazards caused by external factors.

[0054] After the alarm execution unit completes the alarm action, the feedback confirmation unit sends a feedback signal to the low-voltage battery BMS to confirm whether the alarm action has been successfully executed; if the alarm action has been successfully executed, the feedback confirmation unit verifies the received feedback signal.

[0055] The feedback confirmation unit in the low-voltage battery BMS verifies the integrity and correctness of the received feedback signal, ensuring the integrity and reliability of the working process of the alarm system, and promptly discovering and handling problems such as possible alarm execution failure or signal transmission error.

[0056] The present invention uses an independent low-voltage battery BMS to trigger the alarm. Even if the high-voltage battery BMS has a serious fault or fails, the low-voltage battery BMS can still supply power stably, ensuring that the alarm system continues to work and promptly emits a warning signal, significantly reducing the dependence on the high-voltage battery BMS, enabling the electric vehicle to still have reliable safety protection in extreme situations, effectively avoiding safety risks caused by the failure of the main battery system, and significantly improving the safety performance of the whole vehicle.

[0057] The data recording unit is used to record the occurrence time, type, duration, and system status of the alarm event, providing important data support for subsequent fault diagnosis, system maintenance, and performance optimization, facilitating technicians to analyze the reasons for battery out-of-control and the system's response situation.

[0058] Hardware integration

[0059] Key hardware components such as the CAN transceiver, signal processing unit, and alarm logic unit are compactly integrated into the low-voltage battery BMS and efficiently connected to the vehicle alarm system, forming a system architecture with a compact structure, stable performance, easy installation, and maintenance, reducing the space occupation and cost of the system, and improving the overall performance and safety of the electric vehicle.

[0060] Software integration

[0061] In the low-voltage battery BMS software, functional modules such as signal processing, alarm logic, and data recording are comprehensively integrated. Through a strict compilation and flashing process, the stable operation of the software and the collaborative work of each functional module are ensured, enabling the system to accurately and timely process various signals and data, and realizing reliable alarm functions and data management.

[0062] By integrating key functions in the low-voltage battery BMS, the present invention simplifies the hardware architecture and software design of the system. Compared with the complex communication and data processing processes in the prior art, the present invention reduces the dependence on external devices such as in-vehicle terminals and cloud servers, and reduces the hardware cost and the complexity of development and maintenance of the system. At the same time, the compact system design also helps to reduce the space occupancy and weight of the vehicle, improve the overall performance and market competitiveness of electric vehicles, and enable electric vehicle manufacturers to provide consumers with a safer and more reliable battery monitoring solution at a lower cost.

[0063] In the experimental verification and comparative analysis, the test scenario is to simulate the out-of-control of a high-voltage battery, with the voltage suddenly rising to 600V, the temperature rising to 65°C, and lasting for 30 seconds. The control group is the traditional solution (relying on the VCU and cloud server), and the experimental group is the solution of the present invention. The key data shows that the average alarm response time of the traditional solution is 8.2 seconds, the alarm success rate for network interruption is 35%, and the normal function rate during high-voltage failure is 0%; while the average alarm response time of the solution of the present invention is 1.8 seconds, the alarm success rate for network interruption is 100%, and the normal function rate during high-voltage failure is 100%. The solution of the present invention is significantly superior to the traditional solution in all indicators. The average alarm response time is shortened by 78%, the alarm success rate for network interruption is increased by 65%, and the normal function rate during high-voltage failure is increased by 100%. The conclusion shows that through local processing and independent power supply design, the present invention is significantly superior to the traditional solution in extreme scenarios, verifying the substantial improvement of technical effects.

[0064] In several embodiments provided by the present invention, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are only illustrative. For example, the division of the modules or units is only a logical function division, and there can be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another device, or some features can be ignored or not executed.

[0065] The unit may or may not be physically separated. The components shown as units can be one physical unit or multiple physical units, that is, they can be located in one place, or they can be distributed to multiple different places. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0066] In addition, in each embodiment of the present invention, each functional unit may be integrated into one processing unit, or each unit may exist physically alone, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of a software functional unit.

[0067] If the above-mentioned integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it may be stored in a readable storage medium. Based on such an understanding, the technical solution of the embodiments of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, may be embodied in the form of a software product. The software product is stored in a storage medium and includes several instructions for causing a device (which may be a single-chip microcomputer, a chip, etc.) or a processor to execute all or part of the steps of the methods described in the various embodiments of the present invention. The foregoing storage medium includes: various media such as USB flash drives, mobile hard disks, read-only memories (ROMs), random access memories (RAMs), magnetic disks, or optical discs that can store program codes.

[0068] The above is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions within the technical scope disclosed by the present invention should be covered by the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

Claims

1. An out-of-control alarm system for a high-voltage battery of an electric vehicle based on a low-voltage battery, characterized in that, It includes: A low-voltage battery BMS, which is used to work in cooperation with the high-voltage battery BMS and verify the integrity and correctness of the received feedback signal; A signal processing unit, which is responsible for receiving and decompressing the status signal of the high-voltage battery BMS; An alarm logic unit, which is used to generate an alarm signal according to the processing result of the signal processing unit; An alarm execution unit, which is used to receive the alarm signal, execute the alarm action, and feedback to the feedback confirmation unit; A feedback confirmation unit, which is used to verify the execution situation of the alarm action and send a feedback signal to the low-voltage battery BMS; A data recording unit, which is used to store alarm events and system status data.

2. The high-voltage battery out-of-control alarm system for electric vehicles based on low-voltage batteries according to claim 1, wherein: The low-voltage battery BMS and the high-voltage battery BMS realize data exchange through a communication interface module.

3. The electric vehicle high-voltage battery out-of-control alarm system based on a low-voltage battery according to claim 2, characterized in that: The communication interface module uses a CAN bus as the communication interface, and the physical layer of the CAN bus uses twisted pair to transmit differential signals.

4. A high-voltage battery out-of-control alarm system for an electric vehicle based on a low-voltage battery according to any one of claims 1-3, characterized in that: The status signal includes battery voltage, current, temperature, charge status and fault code, and the alarm signal includes an alarm signal for indicating the abnormality of the high-voltage battery BMS.

5. The high-voltage battery out-of-control alarm system for electric vehicles based on low-voltage batteries according to claim 1, characterized in that: The signal processing unit is centered on an STM32 series microcontroller, has multiple communication interfaces and powerful processing capabilities, and is responsible for receiving and decoding the status signal from the high-voltage battery BMS; collects the analog signals of battery voltage and current through the ADC module and converts them into digital signals, and at the same time uses a temperature sensor to obtain battery temperature data and judge whether there is an abnormality in the high-voltage battery BMS.

6. The high-voltage battery out-of-control alarm system for an electric vehicle based on a low-voltage battery according to claim 5, characterized in that: The judgment of whether there is an abnormality in the high-voltage battery BMS includes comparing the real-time monitored voltage with the preset safe voltage threshold, comparing the temperature data with the preset safe temperature threshold, if the real-time monitored voltage exceeds the preset safe voltage threshold continuously for 3 times or the temperature data exceeds the preset safe temperature threshold continuously for 3 times, it is determined that there is an abnormality in the high-voltage battery BMS and the alarm logic unit is triggered.

7. The high-voltage battery out-of-control alarm system for electric vehicles based on a low-voltage battery according to claim 6, wherein: The alarm logic unit is based on an anomaly detection algorithm based on thresholds. When the signal processing unit determines that there is an abnormality in the high-voltage battery BMS, it immediately triggers an alarm, and judges the fault type according to the fault code sent by the identified high-voltage battery BMS, and sends an alarm instruction to the vehicle alarm system in time.

8. An out-of-control alarm system for a high-voltage battery of an electric vehicle based on a low-voltage battery according to claim 7, characterized in that: After receiving the alarm signal, the alarm execution unit starts the alarm action in the way of double alarm of sound and vision to prompt the abnormality of the high-voltage battery BMS.

9. The electric vehicle high-voltage battery out-of-control alarm system based on a low-voltage battery according to claim 8, wherein: After the alarm execution unit completes the alarm action, the feedback confirmation unit sends a feedback signal to the low-voltage battery BMS to confirm whether the alarm action has been successfully executed; if the alarm action has been successfully executed, the feedback confirmation unit verifies the received feedback signal.

10. A high-voltage battery out-of-control alarm system for an electric vehicle based on a low-voltage battery according to claim 1, characterized in that: The data recording unit is used to record the occurrence time, type, duration of the alarm event and the system status.

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