Lithium battery bms communication isolation method and system based on protection linkage

Abstract

The application provides a lithium battery BMS communication isolation method and system based on protection linkage, and belongs to the technical field of battery management. The method constructs a decay feature vector group by collecting running state data, generates a breakdown risk similarity index, determines a residual safe running time value, reduces manual judgment and post-response lag under the traditional fixed threshold trigger protection mode, improves the timeliness and accuracy of communication isolation protection, detects link state parameters of a backup communication link, generates main-backup link switching decision information and executes main-backup link switching, and completes physical isolation of the communication isolation device. Compared with the traditional fixed threshold trigger protection mode, the application can identify the aging risk of the isolation device in advance and actively switch the communication link, reduce the risk of high pressure entering the low pressure control network, improve the communication safety and operation continuity of the lithium battery BMS, and meet the demand of new energy vehicles and energy storage systems for battery management safety protection.

Description

Technical Field

[0001] This invention belongs to the field of battery management technology, specifically a lithium battery BMS communication isolation method and system based on protection linkage. Background Technology

[0002] In new energy vehicles and energy storage systems, lithium battery management systems are responsible for monitoring battery status and protecting safety. Communication isolation devices connect the high-voltage battery side and the low-voltage control side, and are important components for communication and electrical isolation between the two sides. In actual operation, communication isolation devices are exposed to temperature changes, voltage fluctuations and electromagnetic interference for a long time, and their insulation performance and signal transmission capabilities will change with the use time.

[0003] Existing communication isolation solutions lack in-depth utilization of industrial big data. Most of them use fixed thresholds to trigger protection actions, and protection is usually only activated after the isolation device has obvious failure. They are not timely in responding to situations such as increased leakage current and transmission delay that occur in the early stages of aging. Furthermore, there is a lack of quantitative analysis of data such as leakage current and transmission delay during the aging process of isolation devices. It is impossible to determine how long the device can still operate safely, or to switch the communication link in advance before the device completely fails. The electrical connection path from the high-voltage side to the low-voltage control side may still be connected.

[0004] The information disclosed in the background section is only used to enhance the understanding of the background of this disclosure and does not necessarily represent that the information belongs to the prior art known to those skilled in the art. Summary of the Invention

[0005] In view of this, this disclosure provides a lithium battery BMS communication isolation method and system based on protection linkage, which can predict the breakdown risk and switch the communication link in advance before the communication isolation device completely fails, thereby ensuring the communication security and operational continuity of the lithium battery management system.

[0006] In a first aspect, embodiments of this application provide a lithium battery BMS communication isolation method based on protection linkage. The method includes: collecting operating status data of a communication isolation device configured on the main communication link; constructing an attenuation feature vector group based on the operating status data; generating a breakdown risk similarity index based on the attenuation feature vector group; determining the remaining safe operating time value of the communication isolation device based on the breakdown risk similarity index; detecting link status parameters of a backup communication link based on the remaining safe operating time value, wherein the backup communication link is a backup link of the main communication link; generating primary / backup link switching decision information based on the remaining safe operating time value and the link status parameters; and performing primary / backup link switching based on the primary / backup link switching decision information to complete the physical isolation of the communication isolation device.

[0007] Secondly, embodiments of this application provide a lithium battery BMS communication isolation system based on protection linkage. This system may include an operating status acquisition module, a risk index generation module, a link status detection module, a switching decision generation module, and a switching execution module. The operating status acquisition module is used to collect operating status data of the communication isolation device installed on the main communication link and construct an attenuation feature vector group based on the operating status data. The risk index generation module is used to generate a breakdown risk similarity index based on the attenuation feature vector group and determine the remaining safe operating time value of the communication isolation device based on the breakdown risk similarity index. The link status detection module is used to detect the link status parameters of the backup communication link based on the remaining safe operating time value, where the backup communication link is a backup link of the main communication link. The switching decision generation module is used to generate primary / backup link switching decision information based on the remaining safe operating time value and the link status parameters. The switching execution module is used to execute the primary / backup link switching based on the primary / backup link switching decision information, completing the physical isolation of the communication isolation device.

[0008] This application provides a lithium battery BMS communication isolation method and system based on protection linkage. By collecting operational status data and constructing a decay feature vector group, a breakdown risk similarity index is generated and the remaining safe operating time is determined. Based on this, the link status parameters of the backup communication link are detected, and primary / backup link switching decision information is generated. Based on industrial big data, the aging risk of isolation devices is identified in advance, and the primary / backup link switching is performed, completing the physical isolation of the backup communication link. Preventive switching of the communication link is achieved before the communication isolation device completely fails, blocking the direct electrical connection path from the high-voltage side to the low-voltage control side. Compared with traditional fixed threshold triggered protection methods, this invention can identify the aging risk of isolation devices in advance and actively switch the communication link, reducing the risk of high voltage intrusion into the low-voltage control network, improving the communication security and operational continuity of the lithium battery management system, and meeting the battery management safety protection needs of new energy vehicles and energy storage systems. Attached Figure Description

[0009] To more clearly illustrate the technical solutions in the embodiments or conventional technologies of this disclosure, the accompanying drawings used in the description of the embodiments or conventional technologies will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0010] Figure 1 This is a flowchart illustrating a lithium battery BMS communication isolation method based on protection linkage provided in an exemplary embodiment of this application.

[0011] Figure 2This is a flowchart illustrating a lithium battery BMS communication isolation method based on protection linkage, provided in another exemplary embodiment of this application.

[0012] Figure 3 This is a flowchart illustrating a lithium battery BMS communication isolation method based on protection linkage, provided in another exemplary embodiment of this application.

[0013] Figure 4 This is a flowchart illustrating a lithium battery BMS communication isolation method based on protection linkage, provided in another exemplary embodiment of this application.

[0014] Figure 5 This is a flowchart illustrating a lithium battery BMS communication isolation method based on protection linkage, provided in another exemplary embodiment of this application.

[0015] Figure 6 This is a flowchart illustrating a lithium battery BMS communication isolation method based on protection linkage, provided in another exemplary embodiment of this application. Detailed Implementation

[0016] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the examples set forth herein; rather, they are provided so that this disclosure will be more comprehensive and complete, and will fully convey the concept of the exemplary embodiments to those skilled in the art. The described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are set forth to give a full understanding of embodiments of this disclosure.

[0017] The terms “a,” “one,” and “the” are used to indicate the existence of one or more elements / components / etc.; the terms “including” and “having” are used to indicate an open-ended inclusion and that other elements / components / etc. may exist in addition to those listed. The terms “first” and “second” are used only as markers and are not a limitation on the number of objects.

[0018] It should be noted that existing lithium battery BMS communication isolation solutions mostly use fixed threshold triggering protection, which usually only activates the protection action after the isolation device has a significant failure. This results in a delayed response to situations such as increased leakage current and changes in transmission delay that occur in the early stages of aging. Furthermore, existing solutions lack quantitative analysis of the operating status data of the isolation device, making it difficult to determine the remaining safe operating time of the device based on parameters such as leakage current and transmission delay. They also cannot switch the communication link in advance before the device completely fails, and the electrical connection path from the high-voltage side to the low-voltage control side may still be connected, affecting the communication security and operational continuity of the battery management system.

[0019] Therefore, to address the issues of delayed protection actions, difficulty in determining the remaining safe operating time, and untimely switching between primary and backup links, this paper proposes a method to collect operational status data of communication isolation devices installed on the primary communication link and construct attenuation feature vector groups. This generates a breakdown risk similarity index and determines the remaining safe operating time value. Based on this, the link status parameters of the backup communication link are detected, primary and backup link switching decision information is generated, primary and backup link switching is executed, and physical isolation of the backup communication link is completed, providing technical support for the communication isolation safety protection of lithium battery BMS.

[0020] This disclosure provides a lithium battery BMS communication isolation method and system based on protection linkage, such as Figure 1 The method and system for communication isolation of a lithium battery BMS based on protection linkage are shown. The method may include the following steps: Step S110: Collect the operating status data of the communication isolation device set on the main communication link, and construct an attenuation feature vector group based on the operating status data; Step S120: Generate a breakdown risk similarity index based on the attenuation feature vector group, and determine the remaining safe operating time of the communication isolation device based on the breakdown risk similarity index; Step S130: Detect the link status parameters of the backup communication link based on the remaining safe runtime value, wherein the backup communication link is the backup link of the main communication link; Step S140: Generate primary / backup link switching decision information based on the remaining safe runtime value and the link status parameters; Step S150: Perform primary / backup link switching according to the primary / backup link switching decision information to complete the physical isolation of the communication isolation device.

[0021] According to the lithium battery BMS communication isolation method and system based on protection linkage provided in this disclosure, the method can construct an attenuation feature vector group by collecting the operating status data of the communication isolation device set on the main communication link; generate a breakdown risk similarity index based on the attenuation feature vector group to determine the remaining safe operating time value of the communication isolation device; detect the link status parameters of the backup communication link through the remaining safe operating time value; generate primary and backup link switching decision information based on the remaining safe operating time value and the link status parameters, and execute the primary and backup link switching to complete the physical isolation of the communication isolation device.

[0022] In the above method, attenuation feature vector groups are constructed by collecting operating status data, and a breakdown risk similarity index is generated to determine the remaining safe operating time. This reduces the manual judgment and post-event response lag under the traditional fixed threshold triggering protection method, improves the timeliness and accuracy of communication isolation protection, detects the link status parameters of the backup communication link, generates primary and backup link switching decision information and executes the primary and backup link switching, and completes the physical isolation of the communication isolation device. Compared with the traditional fixed threshold triggering protection method, this invention can identify the aging risk of isolation devices in advance and actively switch communication links based on industrial big data, reduce the risk of high voltage entering the low voltage control network, improve the communication security and operational continuity of lithium battery BMS, and meet the battery management safety protection needs of new energy vehicles and energy storage systems.

[0023] The following is a detailed description of each step of the lithium battery BMS communication isolation method and system based on protection linkage provided in this disclosure: In the embodiments of this disclosure, step S110, which involves collecting operational status data of the communication isolation device installed on the main communication link and constructing an attenuation feature vector group based on the operational status data, further includes the following steps: Figure 2 As shown, the specific content is as follows: Step S210: Collect the operating status data of the communication isolation device set on the main communication link. The operating status data includes the instantaneous value of leakage current, the transmission delay jitter sequence, the current operating temperature, the dielectric loss tangent, the insulation resistance attenuation rate, and the partial discharge level. Step S220: Extract the leakage current fluctuation amplitude from the instantaneous value of the leakage current, extract the transmission delay peak offset from the transmission delay jitter sequence, and construct an initial attenuation feature group based on the leakage current fluctuation amplitude and the transmission delay peak offset; Step S230: Determine the coupling relationship based on the current operating temperature and the dielectric loss tangent; Step S240: Construct an attenuation feature vector group based on the initial attenuation feature group and the coupling relationship.

[0024] Specifically, in this embodiment, the communication isolation device is installed in the main communication link of the lithium battery management system (BMS) to connect the high-voltage battery side and the low-voltage control side. The operating status of the communication isolation device is continuously collected through a built-in high-frequency data acquisition unit. For example, during a continuous 72-hour operating cycle, the operating status data of the communication isolation module is acquired in real time at a sampling rate of 10000 Hz, forming a leakage current instantaneous value sequence and a transmission delay jitter sequence. The leakage current instantaneous value sequence varies between 2.5 microamps and 3.8 microamps, and the transmission delay jitter sequence fluctuates between 15 microseconds and 22 microseconds. The current operating temperature is simultaneously read as 45.5 degrees Celsius, and the dielectric loss tangent value is obtained as 0.0045 using a digital bridge measurement circuit. The insulation resistance attenuation rate and partial discharge level are extracted from the underlying data bus as components of the operating status data. This embodiment employs a sliding window algorithm to calculate the range of the instantaneous leakage current value sequence. A fixed-length window is gradually slid across the time series, and statistical measures such as the range and mean are calculated for the data within the window to extract local fluctuation characteristics. For example, the difference between the maximum value (3.8 μA) and minimum value (2.5 μA) of the instantaneous leakage current value sequence yields a leakage current fluctuation amplitude of 1.3 μA. Furthermore, a fast Fourier transform algorithm is used to perform frequency domain analysis on the transmission delay jitter sequence, converting the time-domain signal into a frequency-domain signal, identifying the dominant frequency peak, extracting the transmission delay peak offset, and analyzing the received signal power. For instance, the difference between the maximum value (22 μs) and minimum value (15 μs) of the instantaneous leakage current value sequence yields a transmission delay peak offset of 7 μs. A maximum-minimum normalization algorithm is then used to linearly map the 1.3 μA leakage current fluctuation amplitude and the 7 μs transmission delay peak offset, transforming them into dimensionless data ranging from 0 to 1. For example, values ​​of 0.65 and 0.82 are calculated, thus constructing an initial attenuation feature set. The historical temperature sequence and the dielectric loss tangent sequence are calculated. In this embodiment, the Pearson correlation coefficient algorithm can be used to calculate the coupling relationship coefficient between the current operating temperature and the dielectric loss tangent. The Pearson correlation coefficient algorithm is a statistical measure of the degree of linear correlation between two variables, with a value ranging from -1 to 1. The closer the absolute value is to 1, the stronger the correlation. For example, the calculated coupling relationship coefficient is 0.89, and this coupling relationship coefficient is used as an additional dimension. The obtained initial attenuation feature set is combined with the coupling relationship coefficient to construct the attenuation feature vector set.

[0025] Using the above method, key features such as leakage current fluctuation amplitude and transmission delay peak offset can be extracted from the operating status data of communication isolation devices. Combined with the coupling relationship between the current operating temperature and the dielectric loss tangent, an attenuation feature vector group that can reflect the degradation trend of the insulation performance of communication isolation devices can be constructed. This provides a structured data foundation for the generation of the breakdown risk similarity index, the determination of the remaining safe operating time, and the generation of primary and backup link switching decisions.

[0026] In embodiments of this disclosure, step S120, which generates a breakdown risk similarity index based on the attenuation feature vector group and determines the remaining safe operating time of the communication isolation device based on the breakdown risk similarity index, further includes the following steps: Figure 3 As shown, the specific content is as follows: Step S310: Based on the leakage current fluctuation amplitude, read the leakage current fluctuation amplitude record before breakdown from the preset historical breakdown event database; Step S320: Calculate the difference between the leakage current fluctuation amplitude and the leakage current fluctuation amplitude record before breakdown, and combine it with the slope of the change of dielectric loss tangent to generate a breakdown risk similarity index; Step S330: Extract the time series data of the insulation resistance attenuation rate and the partial discharge level based on the breakdown risk similarity index; Step S340: Analyze the time series data and the current operating temperature using polynomial fitting to obtain a trend curve; Step S350: Determine the relationship of change based on the trend curve; Step S360: Calculate the remaining safe operating time of the communication isolation device based on the change relationship.

[0027] Specifically, based on the obtained leakage current fluctuation amplitude, the leakage current fluctuation amplitude record before breakdown is read from the preset historical breakdown event database. This database is pre-established from historical fault records and breakdown test data of the same type of communication isolation device, storing leakage current fluctuation amplitude records for each type of communication isolation device one hour before breakdown. As the communication isolation device continues to operate, the instantaneous value of the leakage current generally increases, such as the leakage current fluctuation amplitude increasing from 1.3 microamps in step S110 to 50 microamps. The preset historical breakdown event database extracts a leakage current fluctuation amplitude record for the same type of communication isolation device one hour before breakdown, which is 4. 5 microamps, 52 microamps, 55 microamps; calculate the difference between the current leakage current fluctuation amplitude of 50 microamps and the recorded leakage current fluctuation amplitude, and assign them to 5, 2, and 5 respectively, weighting them to obtain 4; based on the dielectric loss tangent value in step S110, such as 0.0045, use the least squares method to fit the dielectric loss tangent value data of the past 24 hours, and calculate the change slope as 0.3%; input the difference and the change slope into the preset risk assessment multilayer perceptron model, wherein the preset risk assessment multilayer perceptron model is trained from historical breakdown event data, and outputs a breakdown risk similarity index, such as 85%, through the preset risk assessment multilayer perceptron model; The breakdown risk similarity index is continuously output. When the breakdown risk similarity index reaches a certain value, such as 92%, and exceeds a preset similarity threshold, such as 85%, time-series data of insulation resistance attenuation rate and partial discharge magnitude are extracted based on the breakdown risk similarity index. The "certain value" represents the actual value obtained as the leakage current fluctuation amplitude and the slope of the dielectric loss tangent increase further with the continued operation of the communication isolation device, thus causing the breakdown risk similarity index to continue rising. In this embodiment, it is set to 92%. The preset similarity threshold is set based on the lithium battery BMS safety protection requirements and historical operating experience; in this embodiment, the preset similarity threshold is set to 85%. The time-series data of insulation resistance attenuation rate and partial discharge level were collected in real time during operation and stored in distributed storage nodes, extracting data from the past 72 hours. For example, if the insulation resistance value continuously decreased from an initial 1000 megohms to 800 megohms, the average attenuation rate was calculated to be 0.3% per hour; the partial discharge level nonlinearly increased from 10 picocoulombs to 50 picocoulombs. The time-series data were aligned with synchronously collected operating temperature data from 40°C to 85°C. Based on the current operating temperature (e.g., 45.5°C), the Pearson correlation coefficient algorithm was used to analyze the correlation between insulation resistance attenuation rate, partial discharge level, and the current operating temperature. Polynomial fitting was then used to process the time-series data and the current operating temperature to obtain a trend curve of the aging degree of the communication isolation device as a function of temperature. Based on the trend curve, the relationship between the aging rate of the communication isolation device and temperature was determined; for example, the aging rate doubled for every five-degree Celsius increase in temperature.

[0028] Based on the changing relationship, the real-time feature vector is input into the Long Short-Term Memory Network (LSTM) prediction model for autoregressive calculation. The LSTM prediction model is trained from historical aging data and is used to extrapolate future time points based on the relationship between aging rate and temperature. It extrapolates the time points when the insulation resistance drops below the 100 megohm safety threshold and the partial discharge level exceeds the 120 picocoulomb critical value, and calculates the remaining safe operating time of the communication isolation device. For example, the calculated remaining safe operating time is 142 hours.

[0029] Using the above method, the leakage current fluctuation amplitude in the attenuation feature vector group and the leakage current fluctuation amplitude record before breakdown in the historical breakdown event database can be used to calculate the breakdown risk similarity index. Then, the slope of the change in the dielectric loss tangent value can be combined to generate the breakdown risk similarity index. Then, the time series data of insulation resistance attenuation rate and partial discharge level can be extracted based on the breakdown risk similarity index. Polynomial fitting can be performed in combination with the current operating temperature to obtain the trend curve of aging degree changing with temperature. Then, the relationship between aging rate and temperature can be determined, and the remaining safe operating time of the communication isolation device can be calculated. This provides a basis for subsequent backup communication link detection and primary / backup link switching decisions.

[0030] In the embodiments of this disclosure, step S130, which involves detecting the link status parameters of the backup communication link based on the remaining safe runtime value, wherein the backup communication link is a backup link to the main communication link, further includes the following steps: Figure 4 As shown, the specific content is as follows: Step S410: Based on the remaining safe operating time value, send a connectivity detection signal to the backup communication link; Step S420: Based on the connectivity detection signal, measure the backup link signal attenuation coefficient and transmission bandwidth capacity of the backup communication link; Step S430: Record the deviation ratio between the reference value of the insulation resistance of the backup communication link and the current measured value; Step S440: Use the backup link signal attenuation coefficient, the transmission bandwidth capacity, and the deviation ratio as link status parameters.

[0031] Specifically, based on the calculated remaining safe operating time of the communication isolation device, such as 142 hours, the remaining safe operating time is continuously monitored in real time. When the remaining safe operating time drops to 120 minutes, which is lower than the preset safety warning threshold, such as 150 minutes, a safety warning is triggered, and the control program immediately starts the switching plan. A connectivity detection signal with a frequency of 5 kHz is generated by a signal generator and injected into the backup communication link. The preset safety warning threshold is set according to the degradation rate of the communication isolation device and the maintenance response time.

[0032] After capturing the connectivity probe signal, the receiving node of the backup communication link runs a Fast Fourier Transform algorithm to analyze the signal waveform and extract the received power, such as 50 milliwatts. The received power of 50 milliwatts is then logarithmically compared with the initial power of the transmitting end, such as 100 milliwatts, to obtain a backup link signal attenuation coefficient of 3 dB. The network controller sends a 10,000-byte test data packet to the backup communication link, recording the round-trip time as two milliseconds. Using a throughput estimation algorithm (the data size of the test data packet divided by the transmission time), the current transmission bandwidth capacity is calculated to be 40 megabits per second. A 500-volt DC test voltage is applied to the backup isolator of the backup communication link, and a weak leakage current of 1 microamp is collected. Based on Ohm's law, the current insulation resistance measurement value is calculated to be 500 megohms. A preset insulation resistance reference value, such as 1000 megohms, established from the factory test data of the same model of backup isolator, is retrieved, and the current deviation ratio is found to be 50%. The deviation ratio, along with a timestamp, is synchronously written into the operation log table of the underlying storage array.

[0033] The obtained backup link signal attenuation coefficient, transmission bandwidth capacity, and deviation ratio are used together as the link status parameters of the backup communication link, providing a basis for generating primary and backup link switching decision information.

[0034] Using the above method, a connectivity detection signal can be sent to the backup communication link based on the remaining safe operating time, the signal attenuation coefficient and transmission bandwidth capacity of the backup link can be measured, and the deviation ratio between the baseline value of the insulation resistance of the backup isolator and the current measured value can be recorded as a link status parameter, thereby realizing the effective detection of the status of the backup communication link and providing a data basis for subsequent primary and backup link switching decisions.

[0035] In the embodiments of this disclosure, step S140, which generates primary / backup link switching decision information based on the remaining safe runtime value and the link status parameters, further includes the following steps: Figure 5 As shown, the specific content is as follows: Step S510: Compare the remaining safe runtime value with the preset minimum safe runtime threshold; Step S520: When the remaining safe running time value is lower than the preset minimum safe running time threshold and the backup link signal attenuation coefficient is within the preset normal range, it is determined that the main communication link has entered an unavailable state, the backup communication link is confirmed to have the switching conditions, and main / backup link switching decision information is generated. Step S530: If the remaining safe operating time value is not lower than the preset minimum safe operating time threshold, or if the backup link signal attenuation coefficient is not within the preset normal range, the main communication link shall continue to operate.

[0036] Specifically, after detecting that the remaining safe runtime of the communication isolation device drops below the preset safety warning threshold and the link status parameter detection of the backup communication link is completed, the remaining safe runtime value is continuously monitored in real time. If, as the running time progresses, the remaining safe runtime value further decreases to 22 minutes, which is lower than the preset minimum safe runtime threshold stored in non-volatile memory, such as 30 minutes, the main communication link status assessment mechanism is triggered, and the backup communication link quality detection is started simultaneously. The preset minimum safe runtime threshold needs to be set to trigger the main communication link status assessment in advance when the remaining safe runtime value is insufficient, so as to avoid the communication isolation device from failing before the switch is completed. The backup link signal attenuation coefficient, such as 3 dB, is matched with the preset normal range. In this embodiment, the preset normal range is set according to the transmission distance and signal quality requirements of the backup communication link. The preset normal range is set to 0 to 5 dB, and it is confirmed that the backup link signal attenuation coefficient of 3 dB is completely within the preset normal range. Based on the dual conditions that the remaining safe runtime is lower than the preset minimum safe runtime threshold and the signal attenuation coefficient of the backup link is within the preset normal range, the primary communication link is determined to be unavailable, the backup communication link is confirmed to have the switching conditions, primary and backup link switching decision information is generated, and the routing redirection operation of the underlying data stream is initiated. If the remaining safe runtime value is not lower than the preset minimum safe runtime threshold, or the signal attenuation coefficient of the backup link is not within the preset normal range, it is determined that the backup communication link is not yet ready to take over. The main communication link continues to operate, and the remaining safe runtime value and the link status parameters of the backup communication link continue to be monitored.

[0037] Using the above method, the primary and backup link switching decision information can be generated based on the comparison between the remaining safe runtime value and the preset minimum safe runtime threshold, combined with the backup link signal attenuation coefficient. When the remaining safe runtime value is lower than the threshold and the backup link signal attenuation coefficient is normal, the primary communication link is determined to be unavailable and the backup communication link is confirmed to have the conditions for switching. Otherwise, the primary communication link continues to operate, providing an accurate decision basis for subsequent primary and backup link switching.

[0038] In the embodiments of this disclosure, step S150, which involves performing a primary / backup link switch based on the primary / backup link switch decision information to complete the physical isolation of the communication isolation device, further includes the following steps: Figure 6 As shown, the specific content is as follows: Step S610: The main communication link is equipped with a physical bypass switch. Based on the main / backup link switching decision information, configuration parameters are obtained. Step S620: Generate a control command sequence according to the configuration parameters; Step S630: According to the control command sequence, generate a trigger pulse signal for disconnecting the main communication link and send it to the physical bypass switch, so that the physical bypass switch disconnects the main communication link and performs the main / backup link switching; Step S640: The backup communication link is equipped with a backup isolator, which receives the status feedback signal of the physical bypass switch when the primary / backup link switch is performed; Step S650: Monitor the primary / backup link switching process based on the status feedback signal to obtain the transient interference amplitude; Step S660: When the transient interference amplitude exceeds the preset withstand voltage level of the backup isolator, an alarm command is generated and a switching anomaly prompt information is obtained according to the alarm command. The physical isolation of the backup communication link is suspended according to the switching anomaly prompt information. Step S670: Confirm that the physical bypass switch has disconnected the main communication link based on the status feedback signal, and send a test data frame to the backup communication link and perform cyclic redundancy check; Step S680: When the cyclic redundancy check is performed and the bit error rate is zero, it is confirmed that the backup communication link has been successfully established, and the physical isolation of the communication isolation device is completed.

[0039] Specifically, based on the primary / backup link switching decision information, the primary / backup link switching response time, such as 50.5 milliseconds, and the bypass switch action delay time, such as 12.0 milliseconds, are obtained from the preset configuration parameters. The preset configuration parameters are pre-calibrated by the physical bypass switch's device manual and previous switching test data.

[0040] The real-time collected line voltage data is processed by sliding window averaging and trend analysis. The preset link switching trigger voltage threshold is set to 85% of the standard mains voltage, i.e., 187.0 volts. When the timing control logic detects that the line voltage is lower than the preset link switching trigger voltage threshold of 187.0 volts, and the duration of the drop state reaches the preset difference between the main / backup link switching response time and the bypass switch action delay time, such as 38.5 milliseconds, a control instruction sequence containing a timestamp and action execution code is generated. This control instruction sequence is converted into a square wave trigger pulse signal with a high level of 5.0 milliseconds and an amplitude of 3.3 volts. It is sent to the control pin of the physical bypass switch through a high-speed opto-isolation channel to drive the electromagnetic relay inside the physical bypass switch to disconnect the main communication link. During the operation of the physical bypass switch, the level change in the physical bypass switch is collected at a frequency of 10,000 Hz. In this embodiment, a three-times majority voting algorithm can be used to filter out mechanical jitter. When three high-level signals are read in succession, it is confirmed that the switch is completely closed, and the status feedback signal of the physical bypass switch is received. The line voltage is collected in real time at a sampling rate of 5,000,000 Hz, and the transient peak voltage is extracted using a sliding window peak detection algorithm with a length of 50 sampling points to obtain the transient interference amplitude during the switching process.

[0041] The transient interference amplitude is compared with the preset withstand voltage rating of 5000 volts of the backup isolator. The preset withstand voltage rating of 5000 volts is set based on the withstand voltage capability of the insulation material of the backup isolator and the rated voltage of the high-voltage side of the lithium battery BMS. When the transient interference amplitude exceeds 5000 volts, an alarm command is generated and a switching anomaly prompt message is output, suspending the physical isolation of the backup communication link. When the transient interference amplitude does not exceed 5000 volts, the status feedback signal confirms that the physical bypass switch has disconnected the main communication link, and a pulse width modulation signal is output to drive the solid-state relay matrix to operate, redirecting the data stream to the backup communication link within 2 milliseconds. At the same time, a 1024-byte test data frame is sent to the backup communication link and a cyclic redundancy check is performed.

[0042] When the bit error rate obtained by cyclic redundancy check is zero, the backup communication link is confirmed to be successfully established; a trip command is sent to the vacuum contactor of the main communication link to separate its contacts, and the impedance measurement circuit is activated to inject a low-frequency detection current of 1000 Hz into both ends of the break, and the insulation resistance value on both sides is calculated in real time according to Ohm's law; when the impedance value calculated for 10 consecutive times is greater than the preset impedance threshold, such as 100 megohms, it is determined that the high-voltage side and the low-voltage control side have lost their conductive connection, the current topology is locked, the physical isolation of the backup communication link is completed, and the direct electrical connection path from the high-voltage side to the low-voltage control side is blocked; wherein, the preset impedance threshold is set according to the insulation safety requirements of the high-voltage side and the low-voltage control side.

[0043] Through the above process, configuration parameters are obtained based on the primary / backup link switching decision information, and a control command sequence is generated. A trigger pulse signal is sent to the physical bypass switch to disconnect the primary communication link. During the switching process, the status feedback signal of the physical bypass switch is received, the transient interference amplitude is monitored, and when the transient interference amplitude does not exceed the preset withstand voltage level of the backup isolator, a test data frame is sent to the backup communication link and cyclic redundancy check is performed. When the bit error rate is zero and the impedance values ​​are all greater than the preset impedance threshold, the backup communication link is confirmed to be successfully established and physical isolation is completed. Preventive switching of the communication link is achieved before the communication isolation device completely fails, blocking the electrical connection path from the high-voltage side to the low-voltage control side.

[0044] In the above method, all operations such as data acquisition of operating status, construction of attenuation feature vector groups, generation of breakdown risk similarity index, determination of remaining safe operating time, detection of backup communication links, generation of primary and backup link switching decisions, and execution of physical isolation are automatically executed by the system program, avoiding manual judgment and response delays. The updated link status parameters and switching decisions can be used in real time for the next communication link protection, forming a linkage mechanism between communication isolation device aging prediction and primary and backup link switching. This not only improves the timeliness and reliability of lithium battery BMS communication isolation protection, but also provides a reliable data foundation for subsequent isolation device maintenance, backup link management, and system safe operation.

[0045] This disclosure also provides a lithium battery BMS communication isolation system based on protection linkage. This system may include an operating status acquisition module, a risk index generation module, a link status detection module, a switching decision generation module, and a switching execution module. The operating status acquisition module is used to collect operating status data of the communication isolation device installed on the main communication link and construct an attenuation feature vector group based on the operating status data. The risk index generation module is used to generate a breakdown risk similarity index based on the attenuation feature vector group and determine the remaining safe operating time value of the communication isolation device based on the breakdown risk similarity index. The link status detection module is used to detect the link status parameters of the backup communication link based on the remaining safe operating time value, where the backup communication link is a backup link of the main communication link. The switching decision generation module is used to generate primary / backup link switching decision information based on the remaining safe operating time value and the link status parameters. The switching execution module is used to execute the primary / backup link switching based on the primary / backup link switching decision information, completing the physical isolation of the communication isolation device.

[0046] It should be noted that the embodiments of the lithium battery BMS communication isolation system based on protection linkage provided in this application can be used to execute the processing flow of the embodiments of the lithium battery BMS communication isolation method and system based on protection linkage in the above embodiments. Its functions will not be repeated here, but can be referred to the detailed description of the above method embodiments.

[0047] As described above, the lithium battery BMS communication isolation system based on protection linkage provided in this disclosure constructs a set of attenuation feature vectors by collecting operating status data and generating a breakdown risk similarity index to determine the remaining safe operating time. This reduces manual judgment and post-event response lag under traditional fixed threshold triggering protection methods, improves the timeliness and accuracy of communication isolation protection, detects the link status parameters of the backup communication link, generates primary / backup link switching decision information and executes primary / backup link switching, and completes the physical isolation of the communication isolation device. Compared with traditional fixed threshold triggering protection methods, this invention can identify the aging risk of isolation devices in advance and actively switch communication links, reduce the risk of high voltage entering the low voltage control network, improve the communication safety and operational continuity of the lithium battery BMS, and meet the battery management safety protection needs of new energy vehicles and energy storage systems.

[0048] This disclosure also provides an electronic device including one or more processors and memory resources, represented by a memory, for storing instructions executable by the processor, such as application programs. The application programs stored in the memory may include one or more modules, each corresponding to a set of instructions. Furthermore, the processor is configured to execute instructions to perform the aforementioned lithium battery BMS communication isolation method and system based on protection linkage.

[0049] The electronic device may also include a power supply component configured to perform power management of the electronic device, a wired or wireless network interface configured to connect the electronic device to a network, and an input / output (I / O) interface. The electronic device can be operated based on operating devices stored in memory, such as Windows Server™, Mac OS X™, Unix™, Linux™, FreeBSD™, or similar.

[0050] In one embodiment, a computer device, which may be a server, is also provided. The computer device includes a processor, memory, input / output interfaces (I / O), and a communication interface. The processor, memory, and I / O interfaces are connected via a system bus, and the communication interface is connected to the system bus via the I / O interfaces. The processor of the computer device provides computing and control capabilities. The memory of the computer device includes non-volatile storage media and internal memory. The non-volatile storage media stores an operating system, computer programs, and a database. The internal memory provides an environment for the operation of the operating system and computer programs in the non-volatile storage media. The database of the computer device stores data. The I / O interfaces of the computer device are used for exchanging information between the processor and external devices. The communication interface of the computer device is used for communicating with external terminals via a network connection. When the computer program is executed by the processor, it implements a lithium battery BMS communication isolation method and system based on protection linkage.

[0051] In one embodiment, a computer device is provided, which may be a terminal. The computer device includes a processor, memory, input / output interface, communication interface, display unit, and input device. The processor, memory, and input / output interface are connected via a system bus, and the communication interface, display unit, and input device are also connected to the system bus via the input / output interface. The processor of the computer device provides computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and internal memory. The non-volatile storage medium stores an operating system and computer programs. The internal memory provides an environment for the operation of the operating system and computer programs in the non-volatile storage medium. The input / output interface of the computer device is used for exchanging information between the processor and external devices. The communication interface of the computer device is used for wired or wireless communication with external terminals; wireless communication can be achieved through Wi-Fi, mobile cellular networks, NFC (Near Field Communication), or other technologies. When the computer program is executed by the processor, it implements a lithium battery BMS communication isolation method and system based on protection linkage. The display unit of the computer device is used to form a visually visible image and may be a display screen, a projection device, or a virtual reality imaging device. The display screen can be an LCD screen or an e-ink screen. The input device of the computer device can be a touch layer covering the display screen, or buttons, trackballs, or touchpads set on the casing of the computer device, or external keyboards, touchpads, or mice, etc.

[0052] This disclosure also provides a non-transitory computer-readable storage medium. When the instructions in the storage medium are executed by the processor of the aforementioned electronic device, the electronic device is able to execute a lithium battery BMS communication isolation method and system based on protection linkage, including: collecting operating status data of a communication isolation device set on the main communication link; constructing an attenuation feature vector group based on the operating status data; generating a breakdown risk similarity index based on the attenuation feature vector group; determining the remaining safe operating time value of the communication isolation device based on the breakdown risk similarity index; detecting the link status parameters of a backup communication link based on the remaining safe operating time value, wherein the backup communication link is a backup link of the main communication link; generating primary / backup link switching decision information based on the remaining safe operating time value and the link status parameters; and performing primary / backup link switching based on the primary / backup link switching decision information to complete the physical isolation of the communication isolation device.

[0053] This disclosure can take the form of a computer program product implemented on one or more storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing program code. Computer-readable storage media include permanent and non-permanent, removable and non-removable media, and information storage can be implemented by any method or technology. Information can be computer-readable instructions, data structures, program modules, or other data. Examples of computer storage media include, but are not limited to: phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, magnetic magnetic disk storage or other magnetic storage devices, or any other non-transfer medium that can be used to store information accessible by a computing device.

[0054] It should be noted that although the steps of the lithium battery BMS communication isolation method and system based on protection linkage in this disclosure are described in a specific order in the accompanying drawings, this does not require or imply that these steps must be performed in that specific order, or that all the steps shown must be performed to achieve the desired result. Additional or alternative steps, such as omitting certain steps, combining multiple steps into one step, and / or decomposing one step into multiple steps, should all be considered part of this disclosure.

[0055] It should be understood that this disclosure is not limited to the detailed structure and arrangement of the modules in the lithium battery BMS communication isolation system based on protection linkage presented in this specification. This disclosure can have other embodiments and can be implemented and performed in various ways. The foregoing variations and modifications fall within the scope of this disclosure. It should be understood that this disclosure, as disclosed and defined in this specification, extends to all alternative combinations of two or more individual features mentioned or apparent in the text and / or drawings. All these different combinations constitute multiple alternative aspects of this disclosure. The embodiments described in this specification illustrate the best known mode for implementing this disclosure and will enable those skilled in the art to utilize this disclosure.

Claims

1. A lithium battery BMS communication isolation method based on protection linkage, characterized in that, The method includes: The operating status data of the communication isolation device set on the main communication link is collected, and an attenuation feature vector group is constructed based on the operating status data. The operating status data includes the instantaneous value of leakage current, the transmission delay jitter sequence, the current operating temperature, the dielectric loss tangent, the insulation resistance attenuation rate, and the partial discharge level. Extract the leakage current fluctuation amplitude from the instantaneous value of the leakage current, extract the transmission delay peak offset from the transmission delay jitter sequence, and construct an initial attenuation feature group based on the leakage current fluctuation amplitude and the transmission delay peak offset; The coupling relationship is determined based on the current operating temperature and the tangent of the medium loss angle. Construct an attenuation feature vector group based on the initial attenuation feature group and the coupling relationship; The breakdown risk similarity index is generated based on the attenuation feature vector group, and the remaining safe operating time of the communication isolation device is determined based on the breakdown risk similarity index, including: reading the leakage current fluctuation amplitude record before breakdown from the preset historical breakdown event database based on the leakage current fluctuation amplitude. Calculate the difference between the leakage current fluctuation amplitude and the leakage current fluctuation amplitude record before breakdown, and combine it with the slope of the change of dielectric loss tangent to generate a breakdown risk similarity index. Based on the breakdown risk similarity index, extract the time series data of the insulation resistance attenuation rate and the partial discharge level; A trend curve is obtained based on the time series data and the current operating temperature, and the remaining safe operating time of the communication isolation device is calculated based on the trend curve. The link status parameters of the backup communication link are detected based on the remaining safe runtime value, and the backup communication link is the backup link of the main communication link. Based on the remaining safe runtime value and the link status parameters, primary and backup link switching decision information is generated. The primary / backup link switching is performed based on the primary / backup link switching decision information, thereby completing the physical isolation of the communication isolation device.

2. The lithium battery BMS communication isolation method based on protection linkage as described in claim 1, characterized in that, A trend curve is obtained based on the time series data and the current operating temperature. Based on the trend curve, the remaining safe operating time of the communication isolation device is calculated, including: A trend curve is obtained by analyzing the time series data and the current operating temperature using polynomial fitting. Determine the relationship of change based on the trend curve; The remaining safe operating time of the communication isolation device is calculated based on the aforementioned relationship.

3. The lithium battery BMS communication isolation method based on protection linkage as described in claim 1, characterized in that, The link status parameters of the backup communication link are detected based on the remaining safe runtime value. The backup communication link is a backup link to the main communication link, including: Based on the remaining safe operating time value, a connectivity detection signal is sent to the backup communication link; Based on the connectivity detection signal, the backup link signal attenuation coefficient and transmission bandwidth capacity of the backup communication link are measured; Record the deviation ratio between the reference value and the current measurement value of the insulation resistance of the backup communication link; The backup link signal attenuation coefficient, the transmission bandwidth capacity, and the deviation ratio are used as link status parameters.

4. The lithium battery BMS communication isolation method based on protection linkage as described in claim 1, characterized in that, Based on the remaining safe runtime value and the link status parameters, primary / backup link switching decision information is generated, including: Compare the remaining safe runtime value with the preset minimum safe runtime threshold; If the remaining safe running time is lower than the preset minimum safe running time threshold and the signal attenuation coefficient of the backup link is within the preset normal range, the main communication link is determined to be unavailable, the backup communication link is confirmed to have the switching conditions, and the main and backup link switching decision information is generated. If the remaining safe operating time is not lower than the preset minimum safe operating time threshold, or if the backup link signal attenuation coefficient is not within the preset normal range, the main communication link shall continue to operate.

5. The lithium battery BMS communication isolation method based on protection linkage as described in claim 1, characterized in that, The main communication link is equipped with a physical bypass switch; Performing primary / backup link switching based on the primary / backup link switching decision information, and completing the physical isolation of the communication isolation device includes: Based on the primary / backup link switching decision information, obtain the configuration parameters; Generate a sequence of control commands based on the configuration parameters; According to the control command sequence, a trigger pulse signal for disconnecting the main communication link is generated and sent to the physical bypass switch, so that the physical bypass switch disconnects the main communication link, performs the main / backup link switching, and completes the physical isolation of the communication isolation device.

6. The lithium battery BMS communication isolation method based on protection linkage as described in claim 5, characterized in that, The backup communication link is equipped with a backup isolator; the primary / backup link switch is performed to complete the physical isolation of the communication isolation device, including: When performing the primary / backup link switch, receive the status feedback signal of the physical bypass switch; The transient interference amplitude is obtained by monitoring the primary and backup link switching process based on the status feedback signal. When the transient interference amplitude exceeds the preset withstand voltage level of the backup isolator, an alarm command is generated and a switching anomaly prompt is obtained according to the alarm command. The physical isolation of the backup communication link is then suspended according to the switching anomaly prompt. When the amplitude of the transient interference does not exceed the preset withstand voltage level of the backup isolator, the physical isolation of the communication isolation device is completed.

7. The lithium battery BMS communication isolation method based on protection linkage as described in claim 6, characterized in that, When the amplitude of the transient interference does not exceed the preset withstand voltage level of the backup isolator, the physical isolation of the communication isolation device is completed, including: Based on the status feedback signal, it is confirmed that the physical bypass switch has disconnected the main communication link, and a test data frame is sent to the backup communication link and a cyclic redundancy check is performed. When the cyclic redundancy check is performed and the bit error rate is zero, it is confirmed that the backup communication link has been successfully established, and the physical isolation of the communication isolation device is completed.

8. A lithium battery BMS communication isolation system based on protection linkage, using the method described in any one of claims 1-7, characterized in that, include: The operation status acquisition module is used to acquire the operation status data of the communication isolation device set on the main communication link, and construct an attenuation feature vector group based on the operation status data; The risk index generation module is used to generate a breakdown risk similarity index based on the attenuation feature vector group, and to determine the remaining safe operating time value of the communication isolation device based on the breakdown risk similarity index. The link status detection module is used to detect the link status parameters of the backup communication link based on the remaining safe runtime value, wherein the backup communication link is a backup link of the main communication link. The switching decision generation module is used to generate primary / backup link switching decision information based on the remaining safe runtime value and the link status parameters. The switching execution module is used to perform primary and backup link switching according to the primary and backup link switching decision information, thereby completing the physical isolation of the communication isolation device.

Images