Processing method and processing device for daisy chain communication fault, battery management system and vehicle

Abstract

The invention relates to a daisy chain communication fault processing method and device, a battery management system and a vehicle. The method comprises the following steps: when the current communication state of the daisy chain of the battery management system is verification failure, obtaining the normal communication number of analog front-end chips in the daisy chain; if the normal communication number of the analog front-end chips is smaller than the total number of the analog front-end chips, obtaining the residual electric quantity of the battery and the fault duration time; the battery management system responds to the corresponding fault processing measures according to the power utilization working condition of the vehicle, the electric quantity remaining interval matched with the battery remaining electric quantity and the fault duration time; wherein when the battery residual electric quantity is updated and matched to different electric quantity residual intervals, the battery management system updates and responds to the corresponding fault processing measures according to the corresponding power utilization working conditions, and the fault duration time is recorded again. According to the scheme provided by the invention, different fault processing measures can be flexibly adopted to process the daisy chain communication fault, the battery safety is ensured, and the user experience is improved at the same time.

Description

Technical Field

[0001] The present application relates to the technical field of communication fault processing, and in particular to a method for processing a daisy chain communication fault, a processing device, a battery management system and a vehicle. Background Art

[0002] In new energy vehicles, the battery management system BMS generally uses daisy chain communication. The reliability of daisy chain communication is an important prerequisite for vehicle charging, driving, SOC, fault diagnosis and other functions. At present, in order to ensure driving and battery safety, after diagnosing a daisy chain communication fault, the battery management system will directly adopt the processing method of lowering high voltage and prohibiting vehicle charging and discharging.

[0003] However, under complex vehicle operating conditions and vehicle environments, there is a possibility of occasional failure or false alarm of daisy chain communication failure. Among them, according to actual application cases, false alarm failures are usually caused by occasional internal abnormalities of the analog front-end chip, namely the AFE (AnalogFront End) chip, occasional abnormalities in the wiring harness connection, or external signal interference. Therefore, only monitoring the daisy chain communication failure cannot fully confirm the true cause of the failure. For false alarm communication failures caused by factors such as external signal interference, if too strict fault handling measures are set, it will affect the user experience. Summary of the invention

[0004] In order to solve or partially solve the problems existing in the related technology, the present application provides a method for handling daisy chain communication failures, a processing device, a battery management system and a vehicle, which can flexibly adopt different fault handling measures to handle daisy chain communication failures, thereby ensuring battery safety and improving user experience.

[0005] A first aspect of the present application provides a method for processing a daisy chain communication failure, which includes:

[0006] When the current communication state of the daisy chain of the battery management system is verification failure, obtaining the normal communication quantity of the analog front-end chips in the daisy chain;

[0007] If the number of normal communication of the analog front-end chips is less than the total number of the analog front-end chips, obtaining the remaining battery power and the fault duration;

[0008] The battery management system responds to corresponding fault handling measures according to the power usage condition of the vehicle, the remaining power interval matched by the remaining power of the battery, and the duration of the fault;

[0009] Among them, when the remaining battery power is updated and matched to different remaining power intervals, the battery management system updates the corresponding fault handling measures in response to the corresponding power usage conditions and re-records the fault duration.

[0010] In some implementations, the fault handling measures include a preset first handling measure, a second handling measure and / or a third handling measure; wherein:

[0011] The first processing measure is that the battery management system is configured to disconnect the high voltage from the main circuit load;

[0012] The second processing measure is that the battery management system is configured to limit the maximum allowable current and power during discharge, recharge and charging respectively;

[0013] The third processing measure is that the battery management system maintains the current status.

[0014] In some implementations, the battery management system responds to corresponding fault handling measures based on the power usage condition of the vehicle, the remaining power interval matched by the remaining power of the battery, and the duration of the fault, including:

[0015] If the power usage condition is a charging condition, if the remaining battery power is greater than a first remaining power threshold, and the fault duration reaches a first diagnosis duration t1, the battery management system responds to the first processing measure; and / or

[0016] If the power usage condition is a charging condition, if the remaining battery power is less than or equal to the first remaining power threshold, and the fault duration reaches the first diagnostic duration t1, the battery management system responds to the second processing measure; when the fault duration reaches the second diagnostic duration t2, the battery management system responds to the first processing measure, 0<t1<t2.

[0017] In some implementations, the battery management system responds to corresponding fault handling measures based on the power usage condition of the vehicle, the remaining power interval matched by the remaining power of the battery, and the duration of the fault, including:

[0018] If the power usage condition is a discharge condition, if the remaining battery power is greater than a second remaining power threshold, and the fault duration reaches a first diagnostic duration t1, the battery management system responds to the third processing measure; when the fault duration reaches a third diagnostic duration t3, the battery management system responds to the second processing measure; 0<t1<t3; and / or

[0019] If the power usage condition is a discharging condition, if the remaining battery power is less than or equal to the second remaining power threshold, and the fault duration reaches a first diagnosis duration t1, the battery management system responds to the first processing measure.

[0020] In some embodiments, the method further comprises:

[0021] When the normal communication quantity of the analog front-end chip is 0, if the power usage condition is a charging condition, and the fault duration reaches a first diagnosis duration t1, the battery management system responds to the first processing measure; and / or

[0022] When the normal communication quantity of the analog front-end chip is 0, if the power consumption condition is a discharge condition and the fault duration reaches the first diagnostic duration t1, the battery management system responds to the third processing measure; when the fault duration reaches the second diagnostic duration t2, the battery management system responds to the first processing measure, 0<t1<t2.

[0023] In some embodiments, the method further comprises:

[0024] The remaining power threshold of the remaining power interval is dynamically set according to the power usage conditions and the operating temperature.

[0025] In some implementations, when the current communication state of the daisy chain of the battery management system is verification failure, the method further includes:

[0026] Reconnecting all the analog front-end chips on the daisy chain according to a preset period and a reconnection number, and obtaining corresponding connection results respectively;

[0027] After the number of reconnections is exhausted, the number of normal communication analog front-end chips in the daisy chain is determined based on the result of the last round of reconnection.

[0028] A second aspect of the present application provides a daisy chain communication failure processing device, comprising:

[0029] A communication verification module, used for obtaining the normal communication number of the analog front-end chips in the daisy chain when the current communication state of the daisy chain of the battery management system is verification failure;

[0030] A parameter acquisition module, used for acquiring the remaining battery power and the fault duration if the number of normal communication of the analog front-end chips is less than the total number of the analog front-end chips;

[0031] A fault handling module is used to enable the battery management system to respond to corresponding fault handling measures based on the vehicle's power usage conditions, the remaining power interval that matches the remaining battery power, and the fault duration; wherein, when the remaining battery power is updated and matched to a different remaining power interval, the battery management system updates the corresponding fault handling measures based on the corresponding power usage conditions and re-records the fault duration.

[0032] A third aspect of the present application provides a battery management system, including:

[0033] Processor; and

[0034] The memory stores executable codes thereon, and when the executable codes are executed by the processor, the processor is caused to execute the method as described above.

[0035] A fourth aspect of the present application provides a vehicle, which includes the above-mentioned battery management system.

[0036] A fifth aspect of the present application provides a computer-readable storage medium having executable code stored thereon. When the executable code is executed by a processor of a battery management system, the processor is caused to execute the method described above.

[0037] The technical solution provided by this application may have the following beneficial effects:

[0038] The method for handling daisy chain communication failures of the present application is aimed at the scenario where communication is lost in a certain number of analog front-end chips. Based on different power usage conditions, the remaining power interval matched by the current battery remaining power SOC, and the continuously monitored fault duration, the battery management system dynamically responds to the corresponding fault handling measures, adopts the more stringent first handling measure for high-risk scenarios, and adopts the more relaxed second handling measure or third handling measure for low-risk scenarios. This design takes into account the safety of the battery and the user experience, ensuring the safety of the battery and the user while minimizing the impact of the fault on the user experience.

[0039] Furthermore, the method for handling daisy chain communication failures of the present application distinguishes fault handling measures from four dimensions, including the severity of daisy chain communication loss, charging and discharging conditions, battery SOC, and fault diagnosis time. Among them, strict handling measures are taken for scenarios with higher battery safety risks, and handling measures are appropriately relaxed for scenarios with lower battery safety risks, thereby improving the coverage and robustness of fault handling measures.

[0040] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] The above and other objects, features and advantages of the present application will become more apparent by describing in more detail the exemplary embodiments of the present application in conjunction with the accompanying drawings, wherein the same reference numerals generally represent the same components in the exemplary embodiments of the present application.

[0042] Figure 1 It is a flowchart of a method for handling a daisy chain communication failure shown in the present application;

[0043] Figure 2is another flowchart of a method for handling a daisy chain communication failure shown in the present application;

[0044] Figure 3 It is a schematic diagram of the processing flow after the daisy chain communication verification fails shown in the present application;

[0045] Figure 4 It is a structural schematic diagram of a daisy chain communication failure processing device shown in the present application;

[0046] Figure 5 It is a structural schematic diagram of the battery management system shown in this application. DETAILED DESCRIPTION

[0047] The embodiments of the present application will be described in more detail below with reference to the accompanying drawings. Although the embodiments of the present application are shown in the accompanying drawings, it should be understood that the present application can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided to make the present application more thorough and complete, and to fully convey the scope of the present application to those skilled in the art.

[0048] The terms used in this application are for the purpose of describing specific embodiments only and are not intended to limit this application. The singular forms of "a", "said" and "the" used in this application and the appended claims are also intended to include plural forms unless the context clearly indicates other meanings. It should also be understood that the term "and / or" used herein refers to and includes any or all possible combinations of one or more associated listed items.

[0049] It should be understood that although the terms "first", "second", "third", etc. may be used in this application to describe various information, this information should not be limited to these terms. These terms are only used to distinguish the same type of information from each other. For example, without departing from the scope of this application, the first information may also be referred to as the third information, and similarly, the third information may also be referred to as the first information. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0050] In the related art, when a communication failure occurs in the daisy chain of a battery management system, if a high voltage processing method is uniformly adopted in any scenario to prohibit the vehicle from charging and discharging, it will bring a bad user experience to the vehicle users.

[0051] In response to the above problems, the present application provides a method for handling daisy chain communication failures, which can flexibly adopt different fault handling measures to handle daisy chain communication failures, thereby ensuring battery safety and improving user experience.

[0052] The technical solution of the present application is described in detail below with reference to the accompanying drawings.

[0053] Figure 1 It is a flowchart of a method for handling a daisy chain communication failure shown in the present application.

[0054] See also Figure 1 , a method for processing a daisy chain communication failure shown in the present application includes:

[0055] S110, when the current communication status of the daisy chain of the battery management system is verification failure, obtain the normal communication number of the analog front-end chips in the daisy chain.

[0056] When the battery management system uses a daisy chain communication method, one MCU usually controls multiple analog front-end chips (AFE chips). One AFE chip can be used to sample the voltage and temperature of multiple single cells and collect the sampling information corresponding to each single cell. Each AFE chip communicates with the MCU in a daisy chain manner, forming a loop communication link as a whole. On the daisy chain, each AFE can communicate with the MCU in the forward or reverse direction.

[0057] Whether the MCU and any AFE chip are communicating normally is usually determined by the verification result. The verification method can be, for example, a CRC (Cyclic Redundancy Check) method. The current communication status is the result of the CRC verification during the communication process. The verification results are generally two kinds: verification success and verification failure. If the current communication status of the daisy chain is verification failure, it means that there is a communication abnormality between the MCU and at least one of the AFE chips, which may cause the loss of sampling information of some AFE chips.

[0058] In some implementations, when the current communication state of the daisy chain of the battery management system is verification failure, loopback detection is performed in the reverse direction along the daisy chain to reconnect each front-end sampling chip one by one in sequence; the number of front-end sampling chips that can be successfully reconnected is counted to obtain the number of normal communication of the analog front-end chips in the daisy chain. It can be understood that if a single AFE chip can be successfully reconnected to the MCU, it means that the AFE chip is in a normal communication state; otherwise, the AFE chip is in an abnormal communication state and its corresponding sampling information is lost.

[0059] S120, if the number of normal communication analog front-end chips is less than the total number of analog front-end chips, obtain the remaining battery power and the fault duration.

[0060] Among them, the total number of analog front-end chips on the daisy chain is a known number P, and the normal communication number of analog front-end chips currently detected is Q, and P and Q are both natural numbers. If 0<Q<P, the current battery remaining power SOC and fault duration of the vehicle battery are obtained. In other words, the scenario corresponding to this embodiment is the situation where some AFE chips on the daisy chain lose communication, rather than all AFE chips lose communication.

[0061] In this application, the fault duration is the time that starts after it is detected that any AFE chip loses communication with the MCU and continues.

[0062] S130, the battery management system responds to corresponding fault handling measures according to the vehicle's power usage conditions, the remaining power interval that matches the battery's remaining power, and the fault duration; wherein, when the battery's remaining power is updated and matched to a different remaining power interval, the battery management system updates the corresponding fault handling measures according to the corresponding power usage conditions and re-records the fault duration.

[0063] In the present application, the power usage condition of the vehicle includes a battery discharge condition and a battery charging condition. In some embodiments, the remaining power interval includes multiple intervals, for example, a high interval, a middle interval and a low interval, and the critical value between adjacent remaining power intervals can be a dynamically set remaining power threshold. In some specific embodiments, the low interval can be 0~X2%, the middle interval can be X2%~X1%, the high interval can be X1%~100%, and 0<X2<X1<100. X1 is the first remaining power threshold, which is the critical value between the high interval and the middle interval. X2 is the second remaining power threshold, which is the critical value between the middle interval and the low interval.

[0064] It should be noted that due to the influence of factors such as current sampling error or ambient temperature, there is an error in the calculation of the remaining battery capacity SOC, so the setting of the remaining power threshold of the remaining power interval requires setting a margin. In some implementations, the remaining power threshold of the remaining power interval is dynamically set according to the power usage conditions and the operating temperature. In some implementations, X1% can be selected from 90% to 95%, and X2% can be selected from 5% to 10%.

[0065] For example, under charging conditions, the amount of electricity that can be charged is different when the battery's operating temperature is different. Usually under normal temperature conditions, the amount of electricity after charging is ≥ 100% of the rated capacity. However, under low temperature conditions, the battery cannot be fully charged, that is, the amount of electricity after charging may be less than 100% of the rated capacity, and the corresponding SOC is relatively lower. Therefore, in order to avoid overcharging the battery, under battery charging conditions, X1 in the high range should be set to a relatively smaller value to ensure battery safety.

[0066] Under discharge conditions, X2 can be a dynamic value. It is understandable that batteries usually have different discharge capabilities at different temperatures. For example, under extremely low temperature conditions, the amount of electricity that a battery can discharge is much less than that discharged under normal temperature conditions. At this time, X2 should not only consider the calculation error of SOC, but also the discharge capacity of the battery. Therefore, in order to avoid over-discharge of the battery voltage, under battery discharge conditions, the value of X2 corresponding to the low range should be set higher.

[0067] That is to say, when the power usage conditions are different, the remaining power threshold corresponding to each remaining power interval can be set dynamically and flexibly. For example, the value of X1 under charging conditions is different from that of X1 under discharging conditions; the value of X2 under discharging conditions is different from that of X2 under charging conditions.

[0068] Furthermore, during the driving of the vehicle, the battery is in a discharging condition, and the current remaining battery power is in a middle range or a low range. If the communication failure continues to occur, the vehicle generates energy feedback due to braking, causing the remaining battery power to rise from the middle range to the high range, or from the low range to the middle range, thereby matching different fault handling measures. In order to avoid the problem of frequent switching of fault handling strategies caused by repeated changes in the SOC period in this scenario, in some implementations, a remaining power threshold under the discharging condition is pre-set, and the remaining power threshold under the discharging condition is greater than the remaining power threshold under the charging condition. That is, X1 under the charging condition is less than X1 under the discharging condition; X2 under the charging condition is less than X2 under the discharging condition.

[0069] In this step, the currently detected remaining battery power can be matched with various remaining power intervals under preset corresponding power application conditions to determine the current remaining power interval, and then select the corresponding fault handling measures.

[0070] In this application, in order to deal with different fault scenarios, multiple fault handling measures can be preset. In some implementations, the fault handling measures include a preset first handling measure, a second handling measure and / or a third handling measure; wherein:

[0071] The first treatment measure M1 is that the battery management system is configured to disconnect the high voltage from the main circuit load. The second treatment measure M2 is that the battery management system is configured to limit the maximum allowable current and power during discharge, regeneration and charging respectively. The third treatment measure M3 is that the battery management system maintains the status quo. It can be seen that according to the severity of the measures, M1>M2>M3.

[0072] In some implementations, if the power usage condition is a charging condition, if the remaining battery power is greater than a first remaining power threshold value X1, and the fault duration reaches a first diagnosis duration t1, the battery management system responds to a first processing measure M1.

[0073] In some embodiments, if the power usage condition is a charging condition, if the remaining battery power is less than or equal to the first remaining power threshold value X1, and the fault duration reaches the first diagnostic duration t1, the battery management system responds to the second processing measure M2; when the fault duration reaches the second diagnostic duration t2, the battery management system responds to the first processing measure M1, 0<t1<t2. That is, after the current communication fault lasts for the duration t1, it still exists until it reaches the duration t2, and the battery management system switches from the second processing measure M2 to the first processing measure M1.

[0074] In some embodiments, if the power usage condition is a discharge condition, if the remaining battery power is greater than the second remaining power threshold value X2, and the fault duration reaches the first diagnostic duration t1, the battery management system responds to the third processing measure M3; when the fault duration reaches the third diagnostic duration t3, the battery management system responds to the second processing measure M2; 0<t1<t3. That is, after the current communication fault lasts for the duration t1, it still exists until it reaches the duration t3, and the battery management system switches from the second processing measure to the first processing measure M1.

[0075] In some implementations, if the power usage condition is a discharging condition, if the remaining battery power is less than or equal to the second remaining power threshold value X2, and the fault duration reaches the first diagnosis duration t1, the battery management system responds to the first processing measure M1.

[0076] It can be understood that as the battery continues to charge or discharge, or switches between charging and discharging conditions, the latest monitored battery remaining capacity is updated. When the battery remaining capacity is updated and matched to different remaining capacity intervals, the battery management system updates the corresponding fault handling measures according to the corresponding power usage conditions and re-records the fault duration. In other words, the original recorded fault duration is reset to zero and the timing starts again.

[0077] In summary, for scenarios where some analog front-end chips experience communication loss, the battery management system dynamically responds to corresponding fault handling measures based on different power usage conditions, the remaining power interval matched by the current battery remaining power SOC, and the continuously monitored fault duration. For high-risk scenarios, the more stringent first handling measure is adopted, and for low-risk scenarios, the more relaxed second or third handling measures are adopted. This design takes into account both battery safety and user experience, ensuring the safety of the battery and the user while minimizing the impact of the fault on the user experience.

[0078] See also Figures 2 to 3 , a method for processing a daisy chain communication failure shown in the present application includes:

[0079] S201, when the current communication status of the daisy chain of the battery management system is verification failure, obtain the normal communication quantity of the analog front-end chips in the daisy chain.

[0080] like Figure 3 As shown, when the current communication state of the daisy chain of the battery management system changes from a normal state to a verification failure, a loopback detection is performed on the daisy chain, for example, starting from the second highest AFE chip to the first AFE chip in reverse, and trying to reconnect one by one. During the detection process, if the number of AFE chips that can communicate normally after reconnection is greater than 0, it is judged that the daisy chain communication is partially lost. If the number of AFE chips that can communicate normally after reconnection is equal to 0, it is judged that the daisy chain communication is completely lost.

[0081] When it is detected that all or part of the AFE chips on the daisy chain are in an abnormal communication state of loss of communication, in order to obtain more accurate implementation methods, all the analog front-end chips on the daisy chain are reconnected according to a preset period and number of reconnections, and corresponding reconnection results are obtained respectively; after the number of reconnections is consumed, the number of normal communication analog front-end chips in the daisy chain is determined according to the results of the last round of reconnection.

[0082] For example, if the result of the last reconnection is that the daisy chain communication is partially lost, the preset period is T1; the MCU reconnects with all AFE chips every T1 to obtain the corresponding connection result. If the result of the last reconnection is that the daisy chain communication is completely lost, the preset period is T2; the MCU reconnects with all AFE chips within T2 to obtain the corresponding connection result. Among them, T1 is selected from 10s to 20s, T2 is selected from 100ms to 200ms, and the values ​​of T1 and T2 can be customized.

[0083] Similarly, after the number of reconnections is exhausted, if the number of AFE chips that can communicate normally after the last round of reconnection is greater than 0, it is determined that the daisy chain communication is partially lost, the number of normal communication of the corresponding analog front-end chips is determined, and the subsequent step S202 is executed. If the number of AFE chips that can communicate normally after the last round of reconnection is equal to 0, it is determined that the daisy chain communication is completely lost, and the subsequent step S209 is executed.

[0084] In some implementations, if the number of AFE chips that can communicate normally after the last round of reconnection is equal to the total number of AFE chips, it means that the current communication state of the daisy chain has returned to normal, and there is no need to perform any subsequent steps.

[0085] It is understandable that the daisy chain communication status may change at different times. For example, under strong external interference conditions, the daisy chain communication status may jump from partial loss to complete loss, which depends on the reliability of the hardware and external interference factors. Therefore, according to the normal communication number of the AFE chip of the real-time reconnection diagnosis, the latest daisy chain communication loss status is determined, and then different subsequent steps are selected.

[0086] This step can also refer to the relevant introduction of S110, which will not be repeated here.

[0087] S202, if the number of normal communication analog front-end chips is less than the total number of analog front-end chips, obtain the remaining battery power and the fault duration.

[0088] In this step, if the number Q of normal communication analog front-end chips is less than the total number P of analog front-end chips, 0<Q<P, then the current remaining battery power SOC and fault duration are obtained.

[0089] After this step, one of S203 to S208 is selected for execution according to different power usage conditions, battery remaining power, fault duration and other parameters. If any parameter changes, one of the steps is selected for execution according to the updated parameter.

[0090] S203, if the power usage condition is a charging condition, if the remaining battery power is greater than a first remaining battery power threshold, and the fault duration reaches a first diagnosis duration t1, the battery management system responds to a first processing measure.

[0091] If the vehicle's current power usage condition is a charging condition, the battery remaining power SOC is greater than the first remaining power threshold X1%, and the fault duration reaches the first diagnostic duration t1, the battery management system responds to the first processing measure M1, that is, the battery management system is configured to disconnect the high voltage to the main circuit load.

[0092] The scenario corresponding to this step is a high SOC scenario under charging conditions, SOC>X1%, that is, SOC matches to the high range. At this time, the daisy chain is in a state of partial communication loss, and there is a certain safety risk. Taking into account the calculation error of SOC, in order to avoid overcharging the battery, the value of X1 is set lower. That is, X1 under charging conditions can be set to be smaller than X1 under discharging conditions. This fault scenario should be handled according to the first processing measure M1 to avoid overcharging the battery and ensure the safety of battery charging.

[0093] S204, if the power usage condition is a charging condition, if the remaining battery power is less than or equal to a first remaining power threshold, and the fault duration reaches a first diagnosis duration t1, the battery management system responds to a second processing measure.

[0094] S205, if the power usage condition is a charging condition, if the remaining battery power is less than or equal to a first remaining power threshold, and the fault duration reaches a second diagnosis duration t2, the battery management system responds to a first processing measure.

[0095] The above steps S204 and S205 both correspond to the medium / low SOC scenario under the charging condition, SOC≤X1%, that is, the SOC is matched to the medium range or low range. For relatively low SOC, the corresponding processing measures can be relaxed, and different processing measures can be distinguished according to different diagnostic durations (debounce times). Preset 0<t1<t2, at the medium / low end of SOC, when short-term charging is performed during a fault, the second processing measure M2 can be used to avoid the maximum voltage loss and battery overcurrent. However, it is necessary to avoid charging for a long time during the fault. At this time, switch to the first processing measure M1 and prompt the battery failure to avoid battery overcharging and ensure battery safety.

[0096] S206, if the power usage condition is a discharging condition, if the remaining battery power is greater than a second remaining power threshold, and the fault duration reaches the first diagnosis duration t1, the battery management system responds to a third processing measure.

[0097] The scenario corresponding to this step is the medium / high SOC scenario under the discharge condition, SOC>X2%, that is, the SOC is matched to the medium range or high range. The discharge condition generally means that the vehicle is driving. If it is in the high SOC range and the fault duration is short, the third processing measure M3 is followed, that is, no processing is performed to avoid affecting the normal driving of the vehicle due to false alarm faults, but it is still necessary to prohibit high SOC range feedback charging to avoid the safety hazard of high-end voltage overcharging.

[0098] It can be understood that the SOC matching the middle range is the most commonly used state of the vehicle battery. Therefore, when the fault duration is short, considering the interference and false alarm conditions, the third processing measure M3 is used to process without limiting the feedback power to ensure the normal use of the vehicle.

[0099] S207, if the power usage condition is a discharging condition, if the remaining battery power is greater than a second remaining power threshold, and the fault duration reaches a third diagnosis duration t3, the battery management system responds to a second processing measure.

[0100] After executing S206, it is detected that the fault lasts for a long time and reaches the third diagnostic time t3, 0<t1<t2<t3, which means that instantaneous interference and other situations have been eliminated. At this time, the second processing measure M2 should be followed and a battery failure should be prompted. The vehicle can continue to be used in this scenario and will not affect the user's continued driving.

[0101] S208, if the power usage condition is a discharging condition, if the remaining battery power is less than or equal to a second remaining power threshold, and the fault duration reaches a first diagnosis duration t1, the battery management system responds to a first processing measure.

[0102] The scenario corresponding to this step is the low SOC scenario under discharge conditions, SOC ≤ X2%, that is, the SOC is matched to the low range. It can be understood that due to different temperatures, the battery usually has different discharge capabilities; for example, under extremely low temperature conditions, the amount of electricity that the battery can discharge is much less than under normal temperature conditions. At this time, X2 should not only consider the error in SOC calculation, but also the discharge capacity of the battery. The threshold corresponding to X2 should be set higher. That is, relative to the charging condition, X2 can be set to a different threshold. X2 under charging conditions can be smaller than X2 under discharging conditions.

[0103] S209: If the normal communication quantity of the analog front-end chip is 0, obtain the power usage condition and / or the fault duration.

[0104] If the number of normal communications of the analog front-end chip detected by S201 is 0, it means that all daisy chain communications are lost, which is the most serious communication loss condition. In order to improve the efficiency of fault handling, the current power consumption type and fault duration of the vehicle are determined in time, so as to select strict handling measures to ensure battery safety.

[0105] After this step, one of the subsequent steps S210 to S212 is selected for execution.

[0106] S210: If the power usage condition is a charging condition and the fault duration reaches a first diagnosis duration t1, the battery management system responds with a first processing measure.

[0107] Because the charging condition is related to the safety of battery use, when the daisy chain communication is completely lost, stricter handling measures should be taken. Regardless of the duration of the fault, the battery management system will handle it according to the most stringent first handling measure M1 and prompt the battery fault to avoid battery overcharging.

[0108] S211, if the power usage condition is a discharging condition and the fault duration reaches the first diagnosis duration t1, the battery management system responds to a third processing measure.

[0109] If the vehicle is currently in a discharging condition, and if the fault duration is within a short period of time, that is, it reaches t1 but has not reached t2, the third processing measure M3 is responded to to avoid affecting the normal driving of the vehicle due to misdiagnosis, but at the same time, the feedback current should be prohibited to avoid overcharging of the battery.

[0110] S212: If the power usage condition is a discharge condition and the fault duration reaches the second diagnosis time t2, the battery management system responds to the first processing measure.

[0111] After executing S211, the fault duration reaches t2, indicating that the fault duration is relatively long. The battery management system responds to the first processing measure M1 and prompts the battery fault to ensure vehicle safety.

[0112] For quick understanding, refer to the following Table 1, the method for handling daisy chain communication failures of this application is to distinguish fault handling measures from four dimensions, including the severity of daisy chain communication loss, charging and discharging conditions, battery SOC, fault diagnosis time, etc. Among them, strict handling measures are taken for scenarios with higher battery safety risks, and handling measures are appropriately relaxed for scenarios with lower battery safety risks, so as to improve the coverage and robustness of fault handling measures.

[0113] Table 1

[0114]

[0115] In Table 1, 0<X2<X1<100. 0<t1<t2<t3. Optionally, t1 is selected from 1s to 2s, t2 is selected from 10s to 60s, and t3 is selected from 1min to 5min. The specific values ​​of t1, t2 and t3 can be customized.

[0116] In summary, the method for handling daisy chain communication failures in the present application can take into account both battery safety and user experience, and perform specific analysis and different fault handling measures on daisy chain communication failures under different working conditions. The fault diagnosis is more comprehensive, the strategy coverage is higher, and the robustness of fault diagnosis is improved. It avoids high-voltage processing caused by false fault alarms, and ensures the safety of the battery pack and the user while minimizing the impact of the failure on the user experience.

[0117] Corresponding to the aforementioned application function implementation method embodiment, the present application also provides a daisy chain communication failure processing device and corresponding embodiments.

[0118] Figure 4 It is a structural schematic diagram of a daisy chain communication failure processing device shown in the present application.

[0119] See also Figure 4 The daisy chain communication fault processing device shown in the present application includes a communication verification module 410, a parameter acquisition module 420 and a fault processing module 430. Among them:

[0120] The communication verification module 410 is used to obtain the normal communication number of the analog front-end chips in the daisy chain when the current communication status of the daisy chain of the battery management system is verification failure.

[0121] The parameter acquisition module 420 is used to obtain the remaining battery power and the fault duration if the number of normal communication analog front-end chips is less than the total number of analog front-end chips.

[0122] The fault handling module 430 is used to enable the battery management system to respond to corresponding fault handling measures based on the vehicle's power usage conditions, the remaining power interval that matches the battery's remaining power, and the fault duration; wherein, when the battery's remaining power is updated and matched to a different remaining power interval, the battery management system updates the corresponding fault handling measures based on the corresponding power usage conditions and re-records the fault duration.

[0123] In some specific implementations, the communication verification module 410 is used to reconnect all the analog front-end chips on the daisy chain according to a preset period and number of reconnections when the current communication status of the daisy chain of the battery management system is verification failure, and obtain corresponding connection results respectively; after the number of reconnections is consumed, the normal communication number of the analog front-end chips in the daisy chain is determined according to the results of the last round of reconnection.

[0124] In some specific implementations, the parameter acquisition module 420 is used to obtain the power usage condition and fault duration of the vehicle when the normal communication quantity of the analog front-end chip is 0.

[0125] In some specific embodiments, the fault processing module 430 is used to: if the power usage condition is a charging condition, if the remaining battery power is greater than a first remaining power threshold, and the fault duration reaches a first diagnostic time t1, the battery management system responds to a first processing measure; and / or if the power usage condition is a charging condition, if the remaining battery power is less than or equal to the first remaining power threshold, and the fault duration reaches the first diagnostic time t1, the battery management system responds to a second processing measure; when the fault duration reaches the second diagnostic time t2, the battery management system responds to the first processing measure, 0<t1<t2.

[0126] In some specific embodiments, the fault processing module 430 is used to: if the power usage condition is a discharge condition, if the remaining battery power is greater than a second remaining power threshold, and the fault duration reaches the first diagnostic time t1, the battery management system responds to a third processing measure; when the fault duration reaches the third diagnostic time t3, the battery management system responds to the second processing measure; 0<t1<t3; and / or if the power usage condition is a discharge condition, if the remaining battery power is less than or equal to the second remaining power threshold, and the fault duration reaches the first diagnostic time t1, the battery management system responds to the first processing measure.

[0127] In some specific embodiments, the fault handling module 430 is used to, when the normal communication number of the analog front-end chip is 0, if the power condition is a charging condition, and the fault duration reaches the first diagnostic time t1, the battery management system responds to the first processing measure; and / or when the normal communication number of the analog front-end chip is 0, if the power condition is a discharging condition, and the fault duration reaches the first diagnostic time t1, the battery management system responds to the third processing measure; when the fault duration reaches the second diagnostic time t2, the battery management system responds to the first processing measure, 0<t1<t2.

[0128] Regarding the device in the above embodiment, the specific manner in which each module performs operations has been described in detail in the embodiment of the method, and will not be elaborated again here.

[0129] Figure 5 It is a structural schematic diagram of the battery management system shown in this application.

[0130] See also Figure 5 The battery management system 1000 includes a memory 1010 and a processor 1020. The present application also provides a vehicle, which includes the above-mentioned battery management system.

[0131] The processor 1020 may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or the processor may be any conventional processor, etc.

[0132] The memory 1010 may include various types of storage units, such as system memory, read-only memory (ROM), and permanent storage devices. Among them, ROM can store static data or instructions required by the processor 1020 or other modules of the computer. The permanent storage device may be a readable and writable storage device. The permanent storage device may be a non-volatile storage device that does not lose the stored instructions and data even after the computer is powered off. In some embodiments, the permanent storage device uses a large-capacity storage device (such as a magnetic or optical disk, flash memory) as a permanent storage device. In some other embodiments, the permanent storage device may be a removable storage device (such as a floppy disk, optical drive). The system memory may be a readable and writable storage device or a volatile readable and writable storage device, such as a dynamic random access memory. The system memory may store some or all instructions and data required by the processor at run time. In addition, the memory 1010 may include any combination of computer-readable storage media, including various types of semiconductor storage chips (such as DRAM, SRAM, SDRAM, flash memory, programmable read-only memory), and disks and / or optical disks may also be used. In some embodiments, the memory 1010 may include a readable and / or writable removable storage device, such as a laser disc (CD), a read-only digital versatile disc (such as a DVD-ROM, a double-layer DVD-ROM), a read-only Blu-ray disc, an ultra-density optical disc, a flash memory card (such as an SD card, a mini SD card, a Micro-SD card, etc.), a magnetic floppy disk, etc. The computer-readable storage medium does not include carrier waves and transient electronic signals transmitted wirelessly or wired.

[0133] The memory 1010 stores executable codes, and when the executable codes are processed by the processor 1020 , the processor 1020 can execute part or all of the methods described above.

[0134] In addition, the method according to the present application may also be implemented as a computer program or a computer program product, which includes computer program code instructions for executing some or all of the steps in the above method of the present application.

[0135] Alternatively, the present application can also be implemented as a computer-readable storage medium (or non-temporary machine-readable storage medium or machine-readable storage medium) on which executable code (or computer program or computer instruction code) is stored. When the executable code (or computer program or computer instruction code) is executed by a processor of a battery management system (or server, etc.), the processor executes part or all of the steps of the above-mentioned method according to the present application.

[0136] The embodiments of the present application have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The selection of terms used herein is intended to best explain the principles of the embodiments, practical applications, or improvements to the technology in the market, or to enable other persons of ordinary skill in the art to understand the embodiments disclosed herein.

Claims

1. A method for handling daisy chain communication failure, characterized in that: include: When the current communication state of the daisy chain of the battery management system is verification failure, obtaining the normal communication quantity of the analog front-end chips in the daisy chain; If the number of normal communication of the analog front-end chips is less than the total number of the analog front-end chips, obtaining the remaining battery power and the fault duration; The battery management system responds to corresponding fault handling measures according to the power usage condition of the vehicle, the remaining power interval that matches the remaining power of the battery, and the duration of the fault; Among them, when the remaining battery power is updated and matched to different remaining power intervals, the battery management system updates the corresponding fault handling measures in response to the corresponding power usage conditions and re-records the fault duration.

2. The method according to claim 1, characterized in that: The fault handling measures include a preset first handling measure, a second handling measure and / or a third handling measure; wherein: The first processing measure is that the battery management system is configured to disconnect the high voltage from the main circuit load; The second processing measure is that the battery management system is configured to limit the maximum allowable current and power during discharge, recharge and charging respectively; The third processing measure is that the battery management system maintains the current status.

3. The method according to claim 2, characterized in that The battery management system responds to corresponding fault handling measures according to the power usage condition of the vehicle, the remaining power interval matched by the remaining power of the battery, and the duration of the fault, including: If the power usage condition is a charging condition, if the remaining battery power is greater than a first remaining power threshold, and the fault duration reaches a first diagnosis duration t1, the battery management system responds to the first processing measure; and / or If the power usage condition is a charging condition, if the remaining battery power is less than or equal to the first remaining power threshold, and the fault duration reaches the first diagnostic duration t1, the battery management system responds to the second processing measure; when the fault duration reaches the second diagnostic duration t2, the battery management system responds to the first processing measure, 0<t1<t2.

4. The method according to claim 2, characterized in that: The battery management system responds to corresponding fault handling measures according to the power usage condition of the vehicle, the remaining power interval matched by the remaining power of the battery, and the duration of the fault, including: If the power usage condition is a discharge condition, if the remaining battery power is greater than a second remaining power threshold, and the fault duration reaches a first diagnostic duration t1, the battery management system responds to the third processing measure; when the fault duration reaches a third diagnostic duration t3, the battery management system responds to the second processing measure; 0<t1<t3; and / or If the power usage condition is a discharging condition, if the remaining battery power is less than or equal to the second remaining power threshold, and the fault duration reaches a first diagnosis duration t1, the battery management system responds to the first processing measure.

5. The method according to claim 2, characterized in that: The method further comprises: When the normal communication quantity of the analog front-end chip is 0, if the power usage condition is a charging condition, and the fault duration reaches a first diagnosis duration t1, the battery management system responds to the first processing measure; and / or When the normal communication quantity of the analog front-end chip is 0, if the power consumption condition is a discharge condition and the fault duration reaches the first diagnostic duration t1, the battery management system responds to the third processing measure; when the fault duration reaches the second diagnostic duration t2, the battery management system responds to the first processing measure, 0<t1<t2.

6. The method according to claim 4, characterized in that The method further comprises: The remaining power threshold of the remaining power interval is dynamically set according to the power usage conditions and the operating temperature.

7. The method according to claim 1, characterized in that When the current communication state of the daisy chain of the battery management system is verification failure, the method further includes: Reconnecting all the analog front-end chips on the daisy chain according to a preset period and a reconnection number, and obtaining corresponding connection results respectively; After the number of reconnections is exhausted, the number of normal communication analog front-end chips in the daisy chain is determined based on the result of the last round of reconnection.

8. A daisy chain communication failure processing device, characterized in that: include: A communication verification module, used for obtaining the normal communication number of the analog front-end chips in the daisy chain when the current communication state of the daisy chain of the battery management system is verification failure; A parameter acquisition module, used for acquiring the remaining battery power and the fault duration if the number of normal communication of the analog front-end chips is less than the total number of the analog front-end chips; A fault handling module is used to enable the battery management system to respond to corresponding fault handling measures based on the vehicle's power usage conditions, the remaining power interval that matches the remaining battery power, and the fault duration; wherein, when the remaining battery power is updated and matched to a different remaining power interval, the battery management system updates the corresponding fault handling measures based on the corresponding power usage conditions and re-records the fault duration.

9. A battery management system, characterized in that: include: processor; as well as A memory having executable codes stored thereon, which, when executed by the processor, causes the processor to execute the method according to any one of claims 1 to 7.

10. A vehicle, characterized in that: Including the battery management system as claimed in claim 9.

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