Alarm fault processing method and system of battery management system

Abstract

The application discloses a kind of battery management system's alarm failure processing method and system, set the multiple alarm levels of fault type;According to the order from high to low of the level of alarm level, whether the alarm limit flag bit is set is judged, if the alarm limit flag bit of high alarm level is set, then end alarm limit flag bit judgment;Otherwise, continue to judge whether the alarm limit flag bit of low alarm level is set, until the judgment of whether the alarm limit flag bit of all alarm levels is set is completed;After corresponding fault type alarm limit flag bit whether the judgment of setting is completed, the control of relay is carried out.The application places the fault diagnosis of BMS in a subprogram module, additionally, the control of relay is placed in another subprogram module independent operation, and detailed diagnosis and control process are formulated, so that fault processing is more clear and reliable.

Description

Technical Field

[0001] This invention belongs to the field of automotive technology, specifically relating to a method and system for handling alarm faults in a battery management system. Background Technology

[0002] In new energy vehicles, the Battery Management System (BMS) plays a crucial role, carrying out detailed strategies for various operating conditions of the power battery, as well as the safety, fault handling, and relay control of the entire vehicle. The fault handling of the battery pack and the control of relays place extremely high demands on the software control logic and architecture of the BMS. Current software architectures handle alarms and faults simultaneously, which not only leads to relay malfunctions but also makes after-sales troubleshooting extremely difficult, requiring significant time to determine the specific cause of the fault. Therefore, a better alarm handling method can not only improve the safety of the entire vehicle but also facilitate simple and accurate fault location for maintenance personnel.

[0003] Currently, the BMS handles power battery alarms by diagnosing each fault through a subroutine. When a fault flag is detected, relay control is activated. However, when the fault is resolved, the relay control cannot be restored. This can lead to malfunctions in the relay control and makes it difficult to accurately determine the root cause when multiple faults occur. If the BMS handles fault diagnosis and control within a single subroutine, the program operation becomes chaotic, easily causing relay malfunctions. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the above-mentioned background technology and provide a method and system for handling alarm faults in a battery management system.

[0005] The technical solution adopted in this invention is: an alarm fault handling method for a battery management system, which sets multiple alarm levels for fault types;

[0006] Based on the alarm levels from high to low, determine whether the alarm over-limit flag is set. If the alarm over-limit flag of the next higher alarm level is set, the determination of the alarm over-limit flag ends; otherwise, continue to determine whether the alarm over-limit flag of the next lower alarm level is set, until the determination of whether the alarm over-limit flag of all alarm levels is completed.

[0007] After determining whether the alarm over-limit flag for the corresponding fault type is set, the relay is controlled.

[0008] Furthermore, the fault types include any one of the following: single cell voltage overvoltage, single cell voltage undervoltage, cell overheating, and excessive temperature difference.

[0009] Furthermore, the multiple alarm levels include three levels: Level 1 alarm, Level 2 alarm, and Level 3 alarm, with Level 1 alarm being higher than Level 2 alarm, which in turn is higher than Level 3 alarm.

[0010] Furthermore, before determining whether the alarm limit flag of the highest alarm level is set, it first determines whether the alarm general function of the fault type is enabled. If so, it obtains the parameters of the fault type and determines whether the alarm limit flag is set; otherwise, it ends the determination of the alarm limit flag.

[0011] Furthermore, for each alarm level, the process of determining whether the alarm limit exceeding flag is set is as follows:

[0012] Step 1: Determine whether the alarm function bit of the alarm level is enabled. If yes, continue to Step 2; otherwise, continue to Step 8.

[0013] Step 2: Compare the fault type parameter with the first set parameter. If the condition is met, continue to Step 3; otherwise, continue to Step 4.

[0014] Step 3: Perform the first timer. If the first timer reaches the first set time, set the alarm over-limit flag of the alarm level to the set value; otherwise, return to step 2.

[0015] Step 4: Determine whether the alarm limit flag of the alarm level is set. If yes, continue to step 5; otherwise, continue to step 9.

[0016] Step 5: Determine whether the alarm level's allow release flag is set. If yes, proceed to step 6; otherwise, proceed to step 9.

[0017] Step 6: Compare the fault type parameter with the second set parameter. If the condition is met, continue to step 7; otherwise, continue to step 9.

[0018] Step 7: Start the second timing. If the second timing reaches the second set time, continue to step 8; otherwise, return to step 6.

[0019] Step 8: Clear the alarm limit flag of the alarm level to zero, and continue to step 9;

[0020] Step 9: Determine whether the alarm limit flag of the next alarm level is set.

[0021] Furthermore, the relay control process is as follows: according to the alarm level from high to low, it is determined whether the alarm over-limit flag is set. If the alarm over-limit flag of the highest alarm level is set, the alarm level of the fault is reported, the power limit is controlled to 0, and the corresponding relay is disconnected; otherwise, it continues to determine whether the alarm over-limit flag of the lower alarm level is set, and according to the alarm level where the alarm over-limit flag is set, the corresponding power limit is controlled to operate.

[0022] Furthermore, after the power limit is 0, a third timing is performed. If the third timing reaches the third set time, the corresponding relay is disconnected.

[0023] An alarm fault handling system for a battery management system, including

[0024] The fault diagnosis module is used to diagnose alarm faults. After the alarm fault diagnosis is completed, a diagnosis completion signal is sent to the relay control module.

[0025] The relay control module is used to control the relays after receiving the diagnostic completion signal.

[0026] Furthermore, the alarm fault diagnosis process is as follows:

[0027] Configure multiple alarm levels for fault types;

[0028] Based on the alarm levels from highest to lowest, the alarm over-limit flag is checked to see if it is set. If the alarm over-limit flag of the next higher alarm level is set, the alarm over-limit flag check ends and the alarm fault diagnosis is completed; otherwise, the alarm over-limit flag check continues to be checked for the next lower alarm level until the alarm over-limit flag check for all alarm levels is completed, at which point the alarm fault diagnosis is complete.

[0029] Furthermore, the control process of the relay is as follows: according to the alarm level from high to low, it is determined whether the alarm over-limit flag is set. If the alarm over-limit flag of the highest alarm level is set, the alarm level of the fault is reported, the power limit is controlled to 0, and the corresponding relay is disconnected; otherwise, it is determined whether the alarm over-limit flag of the lower alarm level is set, and the corresponding power limit is controlled according to the alarm level where the alarm over-limit flag is set.

[0030] The beneficial effects of this invention are:

[0031] This invention places the fault diagnosis of the BMS in a subroutine module, and the control of the relays in another subroutine module to run independently. It also formulates detailed diagnosis and control processes, making fault handling clearer and more reliable.

[0032] This invention assigns a flag bit to each fault, and each fault flag bit is checked cyclically during each program run, with a detailed process defined. Multiple alarm levels are set for each fault, and different levels of fault handling are performed according to the control strategy. The handling of each alarm level is clear and explicit. Attached Figure Description

[0033] Figure 1 This is a flowchart of the alarm fault diagnosis process according to an embodiment of the present invention.

[0034] Figure 2 This is a flowchart illustrating the relay control process according to an embodiment of the present invention. Detailed Implementation

[0035] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings. It should be noted that these descriptions are for the purpose of aiding understanding the present invention, but do not constitute a limitation thereof. Furthermore, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0036] This invention provides a method for handling alarm faults in a battery management system, the process of which is as follows:

[0037] Multiple alarm levels are set for different fault types. These fault types can be any fault that occurs during the operation of the power battery, including any one of the following: single-cell voltage overvoltage, single-cell voltage undervoltage, cell overheating, excessive temperature difference, excessive charging / discharging current, and battery short circuit. The multiple alarm levels include three levels: Level 1 alarm, Level 2 alarm, and Level 3 alarm. Level 1 alarm has a higher level than Level 2 alarm, which in turn has a higher level than Level 3 alarm.

[0038] Based on the alarm levels from highest to lowest, the system checks whether the alarm over-limit flag is set. If the alarm over-limit flag of the next higher alarm level is set, the check ends; otherwise, it continues to check whether the alarm over-limit flag of the next lower alarm level is set, until the alarm over-limit flag checks for all alarm levels are completed. After the check for the alarm over-limit flag corresponding to the fault type is completed, relay control is initiated.

[0039] In the above scheme, before determining whether the alarm limit flag of the highest level alarm is set, it is first determined whether the alarm general function of the fault type is enabled. If so, the parameters of the fault type are obtained, and the alarm limit flag is determined; otherwise, the determination of the alarm limit flag ends.

[0040] In the above scheme, the process of determining whether the alarm limit exceedance flag is set for each alarm level is as follows:

[0041] Step 1: Determine whether the alarm function bit of the alarm level is enabled. If yes, continue to Step 2; otherwise, continue to Step 8.

[0042] Step 2: Compare the fault type parameter with the first set parameter. If the condition is met, continue to Step 3; otherwise, continue to Step 4.

[0043] Step 3: Perform the first timer. If the first timer reaches the first set time, set the alarm over-limit flag of the alarm level to the set value; otherwise, return to step 2.

[0044] Step 4: Determine whether the alarm limit flag of the alarm level is set. If yes, continue to step 5; otherwise, continue to step 9.

[0045] Step 5: Determine whether the alarm level's allow release flag is set. If yes, proceed to step 6; otherwise, proceed to step 9.

[0046] Step 6: Compare the fault type parameter with the second set parameter. If the condition is met, continue to step 7; otherwise, continue to step 9.

[0047] Step 7: Start the second timing. If the second timing reaches the second set time, continue to step 8; otherwise, return to step 6.

[0048] Step 8: Clear the alarm limit flag of the alarm level to zero, and continue to step 9;

[0049] Step 9: Determine whether the alarm limit flag of the next alarm level is set.

[0050] In the above scheme, the relay control process is as follows: according to the alarm level from high to low, it is judged whether the alarm over-limit flag is set. If the alarm over-limit flag of the highest alarm level is set, the alarm level of the fault is reported, the power limit is controlled to 0, and a third timer is performed. If the third timer reaches the third set time, the corresponding relay is disconnected; otherwise, it continues to judge whether the alarm over-limit flag of the lower alarm level is set. According to the alarm level where the alarm over-limit flag is set, the corresponding equipment is controlled to operate at the corresponding power limit.

[0051] To implement the above-mentioned alarm fault handling method, the present invention also provides an alarm fault handling system for a battery management system, including...

[0052] The fault diagnosis module is used to diagnose alarm faults. After the alarm fault diagnosis is completed, a diagnosis completion signal is sent to the relay control module.

[0053] The relay control module is used to control the relays after receiving the diagnostic completion signal.

[0054] In the above scheme, the alarm fault diagnosis process is as follows:

[0055] Configure multiple alarm levels for different fault types.

[0056] Based on the alarm levels from highest to lowest, the alarm over-limit flag is checked to see if it is set. If the alarm over-limit flag of the next higher alarm level is set, the alarm over-limit flag check ends and the alarm fault diagnosis is completed; otherwise, the alarm over-limit flag check continues to be checked for the next lower alarm level until the alarm over-limit flag check for all alarm levels is completed, at which point the alarm fault diagnosis is complete.

[0057] In the above scheme, the control process of the relay is as follows: according to the alarm level from high to low, it is judged whether the alarm over-limit flag is set. If the alarm over-limit flag of the highest alarm level is set, the alarm level of the fault is reported, the power limit is controlled to 0, and the corresponding relay is disconnected; otherwise, it is judged whether the alarm over-limit flag of the lower alarm level is set. According to the alarm level where the alarm over-limit flag is set, the corresponding power limit is controlled to operate.

[0058] Example

[0059] The following is a brief description of a fault causing a single-unit undervoltage alarm, such as... Figure 1 As shown. Other fault alarms should be handled in accordance with this logic; the alarm levels are defined as: Level 3 < Level 2 < Level 1.

[0060] 1. When the subroutine for this alarm runs in a loop, it finds that the individual cell voltage flag is set. Relay control will not be initiated immediately. First, the voltage value and cell number of the individual cell are determined based on the individual cell voltage data. It is then confirmed whether the individual cell voltage level 1 alarm flag (function bit) is enabled. If enabled, and the individual cell voltage reaches the threshold for triggering the alarm, the software will trigger a timer (T1a) to start timing. When the time reaches the alarm delay, the individual cell voltage level 1 alarm flag will be set, and the alarm processing will end.

[0061] 2. If the flag bit is released during the processing of a single-unit voltage level 1 alarm, the threshold of the single-unit voltage level 1 alarm is released, that is, the threshold of the single-unit voltage is higher than the level 1 alarm threshold. At the same time, the software timer (T1b) starts timing. If the threshold of the single-unit voltage is higher than the level 1 alarm threshold within the specified time, the software needs to clear the flag bit of the level 1 alarm to zero, so as to determine whether the flag bit of the level 2 alarm has been reached.

[0062] 3. If, during the processing of a single-unit voltage alarm, the alarm threshold returns to the level 2 alarm (i.e., the undervoltage of the single-unit voltage returns to the level 2 alarm threshold), the software timer (T2a) will start timing. When the alarm value of the single-unit voltage reaches the level 2 alarm requirement within the specified time, the level 2 alarm flag for the single-unit voltage will be set after the alarm time delay has elapsed. The level 2 alarm processing is then complete.

[0063] 4. If the flag bit is released during the processing of a single-unit voltage level 2 alarm, the threshold of the single-unit voltage level 2 alarm is released, that is, the threshold of the single-unit voltage is higher than the level 2 alarm threshold. At the same time, the software timer (T2b) starts timing. If the threshold of the single-unit voltage is higher than the level 2 alarm threshold within the specified time, the software needs to clear the flag bit of the level 2 alarm to zero, so as to determine whether the flag bit of the level 3 alarm has been reached.

[0064] 5. If the flag bit is set during the processing of a single-unit voltage level 3 alarm, meaning the single-unit voltage undervoltage has recovered to the level 3 alarm threshold, the software timer (T3a) will start timing. When the alarm value of the single-unit voltage reaches the level 3 alarm requirement within the specified time, the single-unit voltage level 3 alarm flag will be set after the alarm time delay has elapsed. The level 3 alarm processing ends.

[0065] 6. If the flag is released during the processing of a single-unit voltage level 3 alarm, the threshold of the single-unit voltage level 3 alarm is released, meaning the threshold of the single-unit voltage is higher than the level 3 alarm threshold. At the same time, the software timer (T3b) starts counting. If the threshold of the single-unit voltage is higher than the level 3 alarm threshold within the specified time, the software needs to clear the flag of the level 3 alarm to zero; the process ends.

[0066] The following is a brief description of relay control for a fault causing a single-unit undervoltage alarm, such as... Figure 2 As shown. Its relay control strategy follows this logic; the alarm levels are defined as follows: Level 3 alarm reports a fault, power is limited to 50%; Level 2 alarm reports a fault, power is limited to 20%; Level 1 alarm reports a fault, discharge current is limited to 0 power; and the corresponding relay must be disconnected at the same time.

[0067] The control strategy is as follows:

[0068] 1. When the alarm flag is set to Level 3 alarm, the system will report the corresponding fault level and fault code, and implement a power limitation policy of 50% (without disconnecting the relay);

[0069] 2. When the alarm flag is set to level 2 alarm, the system will report the corresponding fault level and fault code, and implement a power limitation policy of 20% (without disconnecting the relay);

[0070] 3. When the alarm flag is set to Level 1 alarm, the system will report the corresponding fault level and fault code, and implement a power limit of 0% strategy (sequentially cutting off the main positive, heating, and fast charging relays).

[0071] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Contents not described in detail in this specification belong to prior art known to those skilled in the art.

Claims

1. An alarm fault handling system for a battery management system, characterized in that: It includes a fault diagnosis module, which is used to diagnose alarm faults. After the alarm fault diagnosis is completed, a diagnosis completion signal is sent to the relay control module. The relay control module is used to control the relay after receiving the diagnostic completion signal; The alarm fault diagnosis process is as follows: Configure multiple alarm levels for different fault types. Based on the alarm levels from highest to lowest, the alarm over-limit flag is checked to see if it is set. If the alarm over-limit flag of the next higher alarm level is set, the alarm over-limit flag check ends and the alarm fault diagnosis is completed; otherwise, the alarm over-limit flag check continues to be checked for the alarm over-limit flag of the next lower alarm level until the alarm over-limit flag check for all alarm levels is completed, and the alarm fault diagnosis is completed. The control process of the relay is as follows: according to the alarm level from high to low, it is judged whether the alarm over-limit flag is set. If the alarm over-limit flag of the highest alarm level is set, the alarm level of the fault is reported, the power limit is controlled to 0, and the corresponding relay is disconnected; otherwise, it is judged whether the alarm over-limit flag of the lower alarm level is set. According to the alarm level where the alarm over-limit flag is set, the corresponding power limit is controlled to operate.

2. A method for handling alarm faults in a battery management system based on the alarm fault handling system of the battery management system described in claim 1, characterized in that: Configure multiple alarm levels for fault types; Based on the alarm levels from high to low, determine whether the alarm over-limit flag is set. If the alarm over-limit flag of the next higher alarm level is set, the determination of the alarm over-limit flag ends; otherwise, continue to determine whether the alarm over-limit flag of the next lower alarm level is set, until the determination of whether the alarm over-limit flag of all alarm levels is completed. After determining whether the alarm over-limit flag for the corresponding fault type is set, relay control is performed.

3. The alarm fault handling method of the battery management system according to claim 2, characterized in that: The fault types include any one of the following: single cell voltage overvoltage, single cell voltage undervoltage, cell overheating, and excessive temperature difference.

4. The alarm fault handling method of the battery management system according to claim 2, characterized in that: The multiple alarm levels include three levels: Level 1 alarm, Level 2 alarm, and Level 3 alarm. The level of Level 1 alarm is higher than that of Level 2 alarm, which is higher than that of Level 3 alarm.

5. The alarm fault handling method of the battery management system according to claim 2, characterized in that: Before determining whether the alarm limit flag of the highest alarm level is set, first determine whether the alarm general function of the fault type is enabled. If so, obtain the parameters of the fault type and determine whether the alarm limit flag is set; otherwise, end the determination of the alarm limit flag.

6. The alarm fault handling method for the battery management system according to claim 2, characterized in that, For each alarm level, the process of determining whether the alarm limit exceedance flag is set is as follows: Step 1: Determine whether the alarm function bit of the alarm level is enabled. If yes, continue to Step 2; otherwise, continue to Step 8. Step 2: Compare the fault type parameter with the first set parameter. If the condition is met, continue to Step 3; otherwise, continue to Step 4. Step 3: Perform the first timer. If the first timer reaches the first set time, set the alarm over-limit flag of the alarm level to the set value; otherwise, return to step 2. Step 4: Determine whether the alarm limit flag of the alarm level is set. If yes, continue to step 5; otherwise, continue to step 9. Step 5: Determine whether the alarm level's allow release flag is set. If yes, continue to step 6; otherwise, continue to step 9. Step 6: Compare the fault type parameter with the second set parameter. If the condition is met, continue to step 7; otherwise, continue to step 9. Step 7: Start the second timing. If the second timing reaches the second set time, continue to step 8; otherwise, return to step 6. Step 8: Clear the alarm limit flag of the alarm level to zero, and continue to step 9; Step 9: Determine whether the alarm limit flag of the next alarm level is set.

7. The alarm fault handling method of the battery management system according to claim 2, characterized in that: The relay control process is as follows: Based on the alarm level from high to low, determine whether the alarm over-limit flag is set. If the alarm over-limit flag of the highest alarm level is set, report the fault alarm level, control the power limit to 0, and disconnect the corresponding relay; otherwise, continue to determine whether the alarm over-limit flag of the lower alarm level is set, and control the corresponding power limit according to the alarm level where the alarm over-limit flag is set.

8. The alarm fault handling method of the battery management system according to claim 7, characterized in that: After the power limit is 0, a third timer is started. If the third timer reaches the third set time, the corresponding relay is disconnected.

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