Novel SOC over-low protection diagnosis method

Abstract

In order to solve the problem that in the prior art, misinformation is prone to occurring or misinformation does not occur, the novel SOC over-low protection diagnosis method is provided and comprises the four steps of threshold parameter setting, calculation value detecting, fault level judging and corresponding operation executing. According to the method, whether the battery power over-low protection is triggered or not is judged through the current cyclic charging and discharging ampere hours, the strategy is more reasonable, meanwhile, under the under-voltage condition, the whole vehicle has the chance of charging the battery, and the problem that the fault cannot be reported due to the fact that the fault detection time is reset due to frequent charging and discharging of the whole vehicle can be avoided.

Description

Technical Field

[0001] The present invention relates to the field of automobile technology, and in particular to a new diagnostic method for SOC too low protection. Background Art

[0002] In order to implement the basic national policy of saving resources and protecting the environment, promote harmonious coexistence between man and nature, and protect my country's ecological and environmental resources, the country strongly supports the development of new energy vehicles, which has also led to significant development in new energy electric vehicle power batteries.

[0003] As one of the three major components of electric vehicles (battery, motor, and electronic control), the power battery is the power source of the entire vehicle system. It has always been regarded as a landmark technology in the development of electric vehicles. Its performance is directly related to the vehicle's range and its importance to the safety and reliability of the entire vehicle. Current technology has many defects in detecting low battery faults. The most important one is that it is easy to make false alarms or fail to report errors, which can cause battery damage.

[0004] In order to solve the above problems, the Chinese invention patent with patent number CN113352894B proposes a method and system for abnormal power-off protection of power batteries with high voltage. The method is as follows: when the power level of the power battery is lower than the preset battery protection threshold, the battery management system BMS sends a power-off request instruction to the vehicle controller VCU; when the VCU does not respond to the BMS's power-off request, or the MCU does not respond to the VCU's stop working request, the BMS sends a low-voltage relay control instruction, and the low-voltage relay cuts off the power supply to the MCU, so that the MCU stops working and thus stops the operation of the motor. When the power level of the power battery is low, the BMS can cut off the low-voltage power supply system of the MCU, thereby timely cutting off the motor system to protect the battery. By cutting off the low-voltage power supply system, the motor system avoids damage to the power battery, avoids directly cutting off the high-voltage relay with load, and controls the operation of the high-voltage system by cutting off the low-voltage circuit, thereby reducing the probability of failure of the high-voltage relay with load cut-off.

[0005] The power battery high voltage abnormal power failure protection method and system have the following disadvantages: 1. In fault recovery conditions, as the battery is used and its lifespan decreases, the accuracy of the battery charge will become increasingly poor, which can easily lead to false alarms.

[0006] 2. In addition, in the fault detection conditions, the detection time is required. If the battery is charged with a certain current during this period and discharged with the same current for the same time, the battery power will drop to 0, but no error will be reported. Summary of the Invention

[0007] The present invention mainly solves the problem of easy false alarm or false alarm in the prior art, and provides a new diagnosis method for low SOC protection.

[0008] The above technical problems of the present invention are mainly solved by the following technical solutions: A new diagnostic method for low SOC protection, characterized by comprising the following steps: S1. Set relevant threshold parameters; S2, detecting the battery power, the current cycle accumulated discharge ampere-hours, and the current cycle accumulated charge ampere-hours; S3. Determine the current battery power failure level; S4. Perform corresponding operations according to the level of the fault.

[0009] The present invention can accurately report the fault of low battery power by judging the current cycle charge and discharge ampere-hours, thereby achieving the purpose of protecting the battery.

[0010] As a preferred solution, the threshold parameters include a power threshold, a power consumption threshold and a delay time.

[0011] As a preferred solution, the power threshold includes a first power, a second power and a third power. The first power is greater than the second power, and the second power is greater than the third power. Three power thresholds are defined for later judgment of the fault level.

[0012] As a preferred solution, if the battery charge is less than the first charge, an information-type digital fault code is reported, and the difference between the current cycle's accumulated discharge ampere-hours and the current cycle's accumulated charging ampere-hours is calculated, so as to report an information-type digital fault code when the battery charge drops to any of the three fault levels.

[0013] As a preferred solution, if the battery power is greater than or equal to the second power, the battery power fault level is a first-level fault, and the second power is used as a dividing point to distinguish the first-level fault from other faults.

[0014] As a preferred solution, if the battery power is less than the second power, the power difference is compared with the power consumption threshold to determine whether it is a second-level fault.

[0015] As a preferred solution, if the power difference is greater than the power consumption threshold, the battery power is compared with the third power to determine whether the fault level is the second level or the third level.

[0016] As a preferred solution, if the battery power level is greater than or equal to the third power level, the battery power fault level is a second-level fault, and the field effect transistor is disconnected after a set delay time.

[0017] As a preferred solution, if the battery power is less than the third power level, the battery power fault level is a third level fault, and the field effect transistor is immediately disconnected to prevent further damage to the battery and protect the safety of the driver and the vehicle.

[0018] As a preferred solution, when the battery power failure level is the third level, the driver must go to the after-sales service and use the UDS service to start the vehicle. The third level failure requires the battery to be sent to the manufacturer for diagnosis to ensure the safety of personnel.

[0019] Therefore, the advantages of the present invention are: The vehicle environment is complex, and it is a more reasonable diagnostic method to determine whether the low battery protection is triggered by the current cycle charge and discharge ampere-hours. At the same time, in the case of undervoltage, the vehicle also has the opportunity to charge the battery, which can avoid the problem of not being able to report the fault due to the fault detection time being reset due to frequent charging and discharging of the vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a flow chart of the present invention; Figure 2 It is a schematic diagram of the present invention. DETAILED DESCRIPTION

[0021] The technical solution of the present invention will be further specifically described below through embodiments and in conjunction with the accompanying drawings.

[0022] Example 1: A new diagnostic method for SOC low protection includes the following steps: S1. Monitoring battery charge is crucial in electric vehicle use. To better protect the battery and extend its lifespan, setting relevant threshold parameters is essential. The charge threshold is a threshold percentage of the battery charge. Setting relevant threshold parameters includes a charge threshold, a power consumption threshold, and a delay time. The charge threshold is a threshold percentage of the battery charge. The charge thresholds can be set, in ascending order, as a first charge, a second charge, and a third charge. These thresholds can be adjusted based on different vehicle models and battery types. Furthermore, since each vehicle startup may consume a certain amount of power, and the maximum possible power consumption is 0.25Ah, setting 0.25A as the power consumption threshold is reasonable. This way, when the battery charge falls below the set first charge, the system will issue an alarm to prompt the user to charge immediately. When the battery charge falls below the second charge, the difference in charge value is further compared with the power consumption threshold to determine whether more urgent action is required.

[0023] In addition to the battery level and power consumption thresholds, the delay time is also an important parameter. Especially when the battery level fault level reaches level 2, the delay time setting can prevent unnecessary field-effect transistor disconnection, ensuring that the driver can start the vehicle within a certain period of time, while also providing a better user experience.

[0024] In summary, setting relevant threshold parameters is crucial for electric vehicle battery management and maintenance, effectively extending battery life and improving battery performance and safety. At the same time, reasonable adjustments must be made based on different vehicle models and battery types to ensure proper battery operation and use.

[0025] S2. After detecting the current battery charge, it is necessary to calculate the accumulated discharge ampere-hours and the accumulated charge ampere-hours of the current cycle based on the values ​​of the discharge current and the charge current. These calculations can accurately evaluate the battery's energy consumption and charging status. Then, the accumulated discharge ampere-hours of the current cycle and the accumulated charge ampere-hours of the current cycle are compared to obtain the difference between them, that is, the charge difference.

[0026] Calculating this charge difference is crucial for understanding the battery's usage status. By analyzing changes in the charge difference, the battery's life, performance, and health status can be inferred. At the same time, monitoring the charge difference also helps to better manage the battery's charging and discharging processes to maintain the battery in good working condition and increase its service life.

[0027] In addition, the calculation of the power difference can also provide real-time feedback to users, informing them of the current remaining power and the estimated usage time, so that users can better understand the battery usage and reasonably arrange charging or save power.

[0028] Therefore, by calculating the difference between the accumulated discharge ampere-hours in the current cycle and the accumulated charging ampere-hours in the current cycle, we can deeply study the performance and health status of the battery and provide users with accurate power information and usage recommendations. This not only helps to optimize battery use and management, but also improves the battery life and performance, bringing users a better usage experience.

[0029] S3. Determining the battery power fault level is a critical task in energy storage power station operations. To more accurately assess the battery's status and fault severity, battery management systems typically set multiple thresholds to define different fault levels. To determine the current battery power fault level, if the battery power level is less than a first level but greater than or equal to a second level, the battery power fault level is determined to be a Level 1 fault. This indicates that the battery power level is below the normal range, but still has a certain amount of energy storage capacity. Next, the current battery power level is compared with the second level. If the battery power level is less than the second level, the power difference is compared with the power consumption threshold. If the power difference is greater than the power consumption threshold, the battery power fault level is determined to be a Level 2 or Level 3 fault, indicating that the battery power is severely low and requires timely charging or battery pack replacement. The battery power level is then compared with the third level. If the battery power level is greater than or equal to the third level, the battery power fault level is determined to be a Level 2 fault. If the battery power level is less than the third level, the battery power fault level is determined to be a Level 3 fault, indicating that the battery power level is very low and has little remaining energy storage capacity.

[0030] Based on the above analysis, battery power failures can be divided into three levels: Level 1, Level 2, and Level 3. This multi-level classification can more accurately reflect the actual battery status, helping operators take timely measures to ensure the normal operation of the energy storage power station.

[0031] S4. If the battery power fault level is a first-level fault, the system will only report an informational digital fault code. If the battery power fault level is a second-level fault, in addition to reporting the informational digital fault code, the system will also need to wait for the set delay time before disconnecting the field effect transistor. If the battery power fault level is a third-level fault, in addition to reporting the informational digital fault code, the system will also immediately disconnect the field effect transistor.

[0032] S5. When the battery power failure level is the second level, the driver can start the vehicle several times until it reaches the third level. When the battery power failure level is the third level, the driver must go to after-sales service and use UDS service to start the vehicle to ensure the safety of people and vehicles.

[0033] Example 2: An electric taxi company in a certain city uses electric vehicles equipped with advanced battery capacity monitoring and fault warning systems. This system sets a series of relevant threshold parameters to ensure safe operation of the batteries and extend their lifespan.

[0034] In daily operations, the company's drivers often face multiple charging and driving cycles, making battery management crucial. According to system settings, when the battery charge falls below a pre-set threshold of 20%, the system automatically issues an alarm, reminding the driver to seek a charging facility as soon as possible. This design prevents situations where the battery is too low to continue driving, improving vehicle reliability and operational efficiency.

[0035] The system also sets a second charge threshold of 10% and a third charge threshold of 5% to more accurately determine the battery's status and health. When the battery level drops to the second charge threshold, the system further checks the difference between the battery's power consumption and the set power consumption threshold. If the difference exceeds the set 3% threshold, the system will issue a more urgent alert, prompting the driver to take immediate action, such as charging as soon as possible or stopping to wait for maintenance personnel.

[0036] At the same time, to avoid unnecessary disconnection of battery power and resulting in difficulty in starting, the system also sets a delay time. When the battery power failure level reaches the second level, the system will disconnect the field effect transistor within a 15-second delay time to ensure that the driver can start the vehicle in a short time and have enough time to find a suitable charging station or perform other maintenance operations.

[0037] By implementing this battery charge monitoring and fault alarm system, the electric taxi company has significantly improved vehicle reliability and safety. Drivers can now more promptly monitor battery status and schedule charging and maintenance, avoiding operational disruptions and additional costs associated with low battery levels and faults. This also extends battery life and reduces environmental impact, aligning with the company's sustainable development strategy.

[0038] In summary, by properly setting relevant threshold parameters and combining them with delay settings, electric taxi companies can effectively manage and protect batteries, improving vehicle reliability and safety. For example, when an electric taxi's battery charge drops below 20%, the system will automatically sound an alarm, reminding the driver to recharge as soon as possible. Furthermore, when the battery charge drops to 10%, if the battery has consumed more than 3% of its charge, the system will issue an urgent alert to the driver to take action. At the second level of battery charge failure, the system will delay disconnecting the battery for 15 seconds to ensure the driver has enough time to start and find a charging station.

[0039] This advanced battery charge monitoring and fault alarm system will play an increasingly important role in future electric transportation, providing users with a more reliable and convenient travel experience.

[0040] Example 3: An energy storage power station in a local industrial park utilizes an advanced battery management system. This system uses discharge and charge current values ​​to calculate battery energy consumption and charging status, accurately assessing the battery's condition and available power. The following is a real-world example, using specific numerical values ​​to illustrate the application of this technology.

[0041] The energy storage station consists of 100 lithium-ion battery packs, each with a rated capacity of 100 Ah and a rated voltage of 3.7 V. To ensure the safe operation of the battery pack and extend its life, the battery management system sets a series of relevant threshold parameters and uses the values ​​of discharge and charge current for calculation and evaluation.

[0042] On a particular day of operation, the battery management system detects that the discharge current for the current cycle is 50 A and the charge current is 30 A. Based on these values, the system can calculate the accumulated discharge ampere-hours for the current cycle and the accumulated charge ampere-hours for the current cycle.

[0043] The calculation formula of discharge ampere-hour is: discharge ampere-hour = discharge current × time; The calculation formula of charging ampere-hour is: charging ampere-hour = charging current × time, Assuming the current cycle duration is 2 hours, then: The accumulated discharge ampere-hours of the current cycle = 50A × 2h = 100Ah; The accumulated charging ampere-hours in the current cycle = 30A×2h=60Ah.

[0044] Next, the system compares the accumulated discharge ampere-hours of the current cycle with the accumulated charge ampere-hours of the current cycle to obtain the difference between them, that is, the power difference.

[0045] The difference in power = the accumulated discharge ampere-hours in the current cycle - the accumulated charge ampere-hours in the current cycle =100Ah-60Ah =40Ah Using this charge differential, the battery management system can accurately assess the battery's energy consumption and charging status. In this case, the charge differential is 40 Ah, indicating that the battery has discharged 40 Ah of energy during this cycle. Based on this value, the system can determine the remaining battery capacity and alert the operator to promptly charge or replace the battery pack to ensure the normal operation of the energy storage station.

[0046] Through this calculation method based on discharge current and charging current, the energy storage power station can monitor the energy status of the battery in real time, improve energy utilization efficiency, extend battery life, and ensure that the battery pack can be charged in time when needed, providing reliable power support for the industrial park.

[0047] In short, by using the discharge and charge current values ​​to calculate the accumulated discharge and charge ampere-hours of the current cycle, we can accurately assess the battery's energy consumption and charging status. The application of this technology in fields such as energy storage power stations can improve the accuracy and efficiency of energy management and ensure the reliability and longevity of battery systems.

[0048] Example 4: Determining the level of battery power failure is a critical task in energy storage power plant operations. To more accurately assess the battery's condition and fault severity, battery management systems typically set multiple thresholds to define different levels of failure. The following details how to determine the level of battery power failure.

[0049] First, assume the first battery charge is 100Ah, the second battery charge is 80Ah, and the third battery charge is 60Ah. If the current battery charge is less than the first charge but greater than or equal to the second charge, the battery charge fault level can be determined to be a Level 1 fault. This means that the battery charge is below the normal range, but still has a certain amount of energy storage capacity.

[0050] Next, if the current battery charge is less than the second charge, the charge difference is compared with the power consumption threshold. Assume the power consumption threshold is 10Ah. If the charge difference is greater than the power consumption threshold, that is, the charge difference exceeds 10Ah, then the battery fault level can be determined to be a Level 2 fault. This indicates that the battery charge is seriously low and requires timely charging or replacement of the battery pack.

[0051] However, if the power difference is less than or equal to the power consumption threshold, further comparison with the third power level is required. If the current battery power level is greater than or equal to the third power level of 60Ah, the battery power fault level can be determined to be a Level 2 fault. This indicates that the battery power level is very low, with only a small amount of energy storage capacity remaining.

[0052] Finally, if the current battery capacity is less than the third capacity of 60Ah, it can be determined that the battery capacity fault level is level 3. This means that the battery capacity is very close to being exhausted and cannot provide effective energy storage capacity.

[0053] Based on the above analysis, battery power failures can be divided into three levels: Level 1, Level 2, and Level 3. This multi-level classification can more accurately reflect the actual battery status, helping operators take timely measures to ensure the normal operation of the energy storage power station.

[0054] It's important to note that the above judgment logic is merely an example and doesn't represent the specific settings in actual applications. In practice, determining the level of battery power failure may involve more parameters and complex algorithms. Each energy storage plant may customize its settings based on its own needs and conditions to achieve optimal operation.

[0055] In summary, by setting different thresholds and comparing the power difference with the power consumption threshold, the level of battery power failure can be determined. This multi-level classification enables a more accurate assessment of battery status and helps operators take appropriate measures to ensure the reliability and stability of the energy storage plant.

[0056] Embodiment 5: In a certain energy storage power station, a set of batteries is used as the primary energy storage device. The station uses an advanced battery management system, which uses different power failure levels and corresponding technical means to identify and handle battery power failures.

[0057] Recently, power station operators discovered an abnormal battery charge. Upon inspection, they found the battery's current charge was 90 Ah, less than the initial charge of 100 Ah. Therefore, they determined the battery charge fault level to be a Level 1 fault. According to system settings, when a Level 1 fault occurs, the system will report an informational digital fault code.

[0058] The operator immediately checked the monitoring system and discovered fault code 001. According to the system's fault code interpretation, 001 indicates that the battery charge is below the normal range. To better understand the battery's condition, the operator decided to further analyze the battery's operating data.

[0059] They noted that in the event of a first-level fault, the system would wait for a set delay time before disconnecting the field-effect transistor. According to the plant's settings, the delay time was set to 30 minutes. During this time, operators closely monitored the battery's operation.

[0060] After 30 minutes, the system automatically disconnects the field-effect transistors in the battery pack according to the set delay time. At this point, the battery pack can no longer provide energy storage capacity, further protecting the safety of the battery.

[0061] To better analyze the cause of the battery failure, operators conducted a more detailed inspection. They discovered that some individual cells in the battery pack were experiencing abnormal discharge, causing the total battery pack capacity to drop. Further diagnosis confirmed that the degradation in overall battery pack performance was due to aging or damage to some of the cells.

[0062] Based on this analysis, operations personnel took appropriate measures. First, they replaced the damaged battery cells to restore normal operation of the battery pack. Second, they strengthened battery monitoring and maintenance, regularly checking battery status and promptly addressing any abnormalities. Finally, they optimized the technology, improving the battery management system's algorithms to enhance accurate battery status monitoring and fault diagnosis capabilities.

[0063] The above practical examples demonstrate that in energy storage power plants, by setting different power failure levels and corresponding technical measures, battery power failures can be promptly identified and addressed. This technical approach protects battery safety, improves the reliability and stability of the battery pack, and ensures the normal operation of the energy storage power plant. Furthermore, by analyzing and addressing battery failures, battery pack performance can be optimized, extending battery life and improving the economic and environmental benefits of the energy storage power plant.

[0064] The specific embodiments described herein are merely illustrative of the spirit of the present invention. Persons skilled in the art may make various modifications, additions, or substitutions to the described specific embodiments without departing from the spirit of the present invention or exceeding the scope of the appended claims.

Claims

1. A new diagnostic method for SOC low protection, characterized in that: The following steps are involved: S1. Set relevant threshold parameters; S2, detecting the battery power, the current cycle accumulated discharge ampere-hours and the current cycle accumulated charge ampere-hours; S3, determining the current battery power failure level; S4. Perform corresponding operations according to the level of the fault.

2. A new diagnostic method for low SOC protection according to claim 1, characterized in that: The threshold parameters include a power threshold, a power consumption threshold and a delay time.

3. A new diagnostic method for low SOC protection according to claim 2, characterized in that: The power threshold includes a first power, a second power and a third power, the first power is greater than the second power, and the second power is greater than the third power.

4. A new diagnostic method for low SOC protection according to claim 2, characterized in that: If the battery power is less than the first power, an information type digital fault code is reported, and the power difference between the current cycle accumulated discharge ampere-hours and the current cycle accumulated charging ampere-hours is calculated.

5. A new diagnostic method for low SOC protection according to claim 4, characterized in that: If the battery power is greater than or equal to the second power, the battery power fault level is a first level fault.

6. A new diagnostic method for low SOC protection according to claim 4 or 5, characterized in that: If the battery power is less than the second power, the power difference is compared with the power consumption threshold.

7. A new diagnostic method for low SOC protection according to claim 5, characterized in that: If the power difference is greater than the power consumption threshold, the battery power is compared with the third power.

8. A new diagnostic method for low SOC protection according to claim 7, characterized in that: If the battery power is greater than or equal to the third power, the battery power fault level is a second-level fault, and the field effect transistor is disconnected after a set delay time.

9. A new diagnostic method for low SOC protection according to claim 7 or 8, characterized in that: If the battery power is less than the third power level, the battery power fault level is a third level fault, and the field effect transistor is immediately disconnected.

10. A new diagnostic method for low SOC protection according to claim 9, characterized in that: When the battery power failure level is the third level, the driver must go to after-sales service and use UDS service to start the vehicle.

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