Method, system and vehicle for processing damaged bottom of battery module in power battery

Abstract

The present invention discloses a method, system and vehicle for handling the bottom damage of a battery module in a power battery. When the bottom of a battery module in a power battery is damaged, the fault level is determined according to the number of battery modules with damaged bottoms in the power battery and the state of the vehicle, and a fault prompt is requested, and the charging power and discharging power of the power battery are limited when power limitation is required. The method can take corresponding handling measures in the first time to avoid thermal runaway caused by battery short circuit due to damage to the bottom of the battery module, and reduce the harm and impact of damage to the bottom of the battery module on the driver and passengers.

Description

Technical Field

[0001] The present invention belongs to the field of new energy vehicle battery management systems, and specifically relates to a method, system and vehicle for processing damaged bottom of a battery module in a power battery. Background Art

[0002] As energy crisis and environmental pollution become increasingly prominent, electric vehicles are increasingly being praised and paid attention to. However, the spontaneous combustion of electric vehicles is a topic that people are afraid to talk about. After investigating and analyzing the spontaneous combustion of electric vehicles, it was found that when users use the vehicles, due to poor road conditions, the power batteries arranged at the bottom of the vehicles are prone to dragging and bumping when the vehicles pass through rough roads, and face the risk of breakdown. The current mainstream ternary lithium batteries are very likely to produce open flames when squeezed and punctured, which will seriously affect the life safety of drivers and passengers.

[0003] In addition, when the battery module is squeezed and deformed, the fault cannot be detected immediately because the battery performance has not changed significantly. It is often not until the vehicle continues to run for a period of time that the change in battery performance parameters triggers other fault diagnosis conditions, and other faults are falsely reported before returning to the repair station to find the root cause of the fault. After the bottom of the battery module is damaged and deformed, the fault cannot be diagnosed and controlled immediately, which will lead to extremely high risks in the subsequent use of the vehicle, such as power interruption and power battery insulation failure. Therefore, how to timely and effectively monitor the damage to the bottom of the battery module and deal with the fault in a timely and effective manner is an important research topic at present. Summary of the invention

[0004] The purpose of the present invention is to provide a method, system and vehicle for processing damage to the bottom of a battery module in a power battery, so as to reduce the harm and impact of the damage to the bottom of the battery module on the driver and passengers.

[0005] The method for handling bottom damage of a battery module in a power battery described in the present invention includes: determining whether the battery module in the power battery has bottom damage; if so, determining the fault level according to the number of battery modules with bottom damage in the power battery and the state of the vehicle, requesting a fault prompt, and limiting the charging power and discharging power of the power battery when power limitation is required.

[0006] Preferably, if the number n of battery modules with damaged bottoms in the power battery is greater than or equal to 1, and the vehicle is stationary, it is determined to be a level N fault, and a request is made to light up the instrument panel fault light, without restricting the charging power and discharging power of the power battery.

[0007] Preferably, if the number n of battery modules with damaged bottoms in the power battery is greater than or equal to 1, and the vehicle is in a driving state, and the vehicle speed is less than or equal to a preset speed threshold, it is determined to be an N+1 level fault, and a request is made to light up the dashboard fault light and request voice and text prompts, and the discharge power of the power battery is smoothly limited to a preset power threshold A within the first preset time, and the charging power of the power battery is directly limited to 0.

[0008] Preferably, if the number n of battery modules with damaged bottoms in the power battery is greater than or equal to 1 and less than a preset first number threshold, and the vehicle is in a driving state, and the vehicle speed is greater than a preset speed threshold, it is determined to be an N+1 level fault, and a request is made to light up the dashboard fault light and request voice and text prompts, and the discharge power of the power battery is smoothly limited to a preset power threshold A within a first preset time, and the charging power of the power battery is directly limited to 0.

[0009] Preferably, if the number n of battery modules with damaged bottoms in the power battery is greater than or equal to a preset first number threshold, and the vehicle is in a driving state, and the vehicle speed is greater than a preset speed threshold, it is determined to be an N+2 level fault, and a request is made to light up the dashboard fault light and request voice and text prompts, and the discharge power of the power battery is smoothly limited to 0 within the first preset time, and the charging power of the power battery is directly limited to 0.

[0010] Preferably, the preset first quantity threshold is 2, the preset vehicle speed threshold is 15 km / h, and the first preset time is 1 min.

[0011] Preferably, the method for determining whether the bottom of the battery module in the power battery is damaged is:

[0012] Obtain the measured resistance values ​​of m resistance strain gauges;

[0013] If the absolute value of the difference between the measured resistance value of a certain resistance strain gauge and the standard resistance value of the resistance strain gauge is less than or equal to the preset resistance threshold, it is determined that the battery module corresponding to the resistance strain gauge has no bottom damage;

[0014] If the absolute value of the difference between the measured resistance value of a certain resistance strain gauge and the standard resistance value of the resistance strain gauge is greater than a preset resistance threshold, it is determined that the battery module corresponding to the resistance strain gauge has bottom damage;

[0015] There are a total of m battery modules in the power battery, and m resistance strain gauges are respectively pasted on the bottom of the m battery modules, and the area of ​​each resistance strain gauge is equal to the area of ​​the bottom of each battery module.

[0016] Preferably, the preset resistance threshold is 2Ω.

[0017] The processing system for the damaged bottom of the battery module in the power battery described in the present invention includes a battery management system, a data acquisition and processing module and m resistance strain gauges, the m resistance strain gauges are respectively pasted on the bottoms of the m battery modules, the area of ​​each resistance strain gauge is equal to the area of ​​the bottom of each battery module, and the m resistance strain gauges are connected to the battery management system through the data acquisition and processing module; the battery management system is programmed to execute the above-mentioned processing method.

[0018] The vehicle of the present invention comprises the above-mentioned processing system.

[0019] The present invention has the following effects:

[0020] When the bottom of the battery module in the power battery is damaged, the fault level is determined according to the number of battery modules with damaged bottoms and the state of the vehicle, and a fault prompt is requested. When power limitation is required, the charging power and discharging power of the power battery are limited. It can take corresponding treatment measures in the first time, avoiding thermal runaway caused by battery short circuit caused by damage to the bottom of the battery module, reducing the risk of vehicle spontaneous combustion, and reducing the harm and impact of damage to the bottom of the battery module on the driver and passengers, thereby ensuring the safety of the driver and passengers from the harm and impact of thermal runaway. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 Schematic diagram of a system for processing damaged bottom of a battery module in a power battery in this embodiment.

[0022] Figure 2 This is a flow chart of a method for processing damaged bottom of a battery module in a power battery in this embodiment. DETAILED DESCRIPTION

[0023] like Figure 1 As shown, in this embodiment, the processing system for the damaged bottom of the battery module in the power battery includes a battery management system, a data acquisition and processing module, and m resistance strain gauges. There are a total of m battery modules in the power battery, and the m resistance strain gauges are respectively pasted on the bottom of the m battery modules, and the area of ​​each resistance strain gauge is equal to the area of ​​the bottom of each battery module. The m resistance strain gauges are connected to the battery management system through the data acquisition and processing module; the battery management system is programmed to execute the following Figure 2 The method for dealing with the damaged bottom of the battery module in the power battery shown.

[0024] like Figure 2 As shown, in this embodiment, the processing method for the damaged bottom of the battery module in the power battery is executed by the battery management system (ie, BMS), and the processing method includes:

[0025] Step 1: Determine whether the bottom of the battery module in the power battery is damaged. If so, proceed to step 2, otherwise end.

[0026] Methods for determining whether the bottom of the battery module in the power battery is damaged include:

[0027] Get the measured resistance values ​​of m resistance strain gauges.

[0028] If the absolute value of the difference between the measured resistance value of a certain resistance strain gauge and the standard resistance value of the resistance strain gauge (which is a known parameter) is less than or equal to a preset resistance threshold, it is determined that the battery module corresponding to the resistance strain gauge has no bottom damage.

[0029] If the absolute value of the difference between the measured resistance value of a certain resistance strain gauge and the standard resistance value of the resistance strain gauge is greater than a preset resistance threshold, it is determined that the battery module corresponding to the resistance strain gauge has bottom damage.

[0030] When the power battery of a vehicle hits the bottom or bumps during driving, if the lower part of the battery box is punctured, the resistance value of the corresponding strain gauge arranged at the bottom of the battery module will change. Therefore, by monitoring the resistance value of the strain gauge in real time, it is possible to monitor whether the bottom of the battery module is damaged, providing evidence for subsequent faults, solving the problem of difficulty in detecting faults caused by damage to the bottom of the battery module.

[0031] Step 2: Count the number n (n is an integer, and n≤m) of battery modules with damaged bottoms in the power battery, and then proceed to step 3.

[0032] Step 3: Determine whether n≥1 and the vehicle is stationary. If yes, execute step 4; otherwise, execute step 5.

[0033] Step 4: Determine that it is a level N fault, request to light up the instrument panel fault light (to remind the driver to check the bottom of the vehicle), do not limit the charging power and discharging power of the power battery, and then end.

[0034] Step 5: Determine whether n≥1, the vehicle is in driving state, and the speed is ≤15km / h (the preset speed threshold in this embodiment is 15km / h). If yes, execute step 7, otherwise execute step 6.

[0035] Step 6: Determine whether 1≤n<2 (the preset first quantity threshold in this embodiment is 2), and the vehicle is in driving state, and the speed is >15km / h. If so, execute step 7, otherwise execute step 8.

[0036] Step 7: Determine that it is a level N+1 fault, request to light up the instrument panel fault light and request voice and text prompts (to guide the driver to the nearest maintenance point), smoothly limit the discharge power of the power battery to the preset power threshold A within 1 minute (the first preset time in this embodiment is 1 minute), and directly limit the charging power of the power battery to 0, and then end. The current driving cycle cannot be restored.

[0037] Step 8: Determine whether n≥2, the vehicle is in driving state, and the speed is greater than 15km / h. If yes, execute step 9, otherwise end.

[0038] Step 9: Determine that it is an N+2 level fault, request to light up the instrument panel fault light and request voice and text prompts (to guide the driver to the nearest maintenance point), smoothly limit the discharge power of the power battery to 0 within 1 minute, and directly limit the charging power of the power battery to 0, and then end. The current driving cycle cannot be restored.

[0039] The vehicle in this embodiment includes the above-mentioned system for processing damage to the bottom of the battery module in the power battery.

Claims

1. A method for treating a damaged bottom of a battery module in a power battery, characterized in that: The method includes: Determine whether the battery module in the power battery has bottom damage; If it occurs, the fault level will be determined according to the number of battery modules with damaged bottoms in the power battery and the state of the vehicle, and a fault prompt will be requested. If power limitation is required, the charging power and discharging power of the power battery will be limited; If the number n of battery modules with damaged bottoms in the power battery is greater than or equal to 1, and the vehicle is in driving state, and the vehicle speed is less than or equal to the preset vehicle speed threshold, it is determined to be an N+1 level fault, and a request is made to light up the instrument panel fault light and request voice or text prompts, and the discharge power of the power battery is smoothly limited to the preset power threshold A within the first preset time, and the charging power of the power battery is directly limited to 0; A method for determining whether a battery module in a power battery is damaged at the bottom is as follows: obtaining measured resistance values ​​of m resistance strain gauges; if the absolute value of the difference between the measured resistance value of a certain resistance strain gauge and the standard resistance value of the resistance strain gauge is greater than a preset resistance threshold, it is determined that the battery module corresponding to the resistance strain gauge is damaged at the bottom; wherein there are a total of m battery modules in the power battery, and the m resistance strain gauges are respectively pasted on the bottoms of the m battery modules, and the area of ​​each resistance strain gauge is equal to the area of ​​the bottom of each battery module.

2. The method for treating the damaged bottom of a battery module in a power battery according to claim 1, characterized in that: If the number n of battery modules with damaged bottoms in the power battery is greater than or equal to 1, and the vehicle is stationary, it is determined to be a level N fault, and a request is made to light up the instrument panel fault light. There is no restriction on the charging power and discharging power of the power battery.

3. The method for treating the damaged bottom of a battery module in a power battery according to claim 1, characterized in that: If the number n of battery modules with damaged bottoms in the power battery is greater than or equal to 1 and less than a preset first number threshold, and the vehicle is in driving state, and the vehicle speed is greater than the preset vehicle speed threshold, it is determined to be an N+1 level fault, and a request is made to light up the dashboard fault light and request voice and text prompts. The discharge power of the power battery is smoothly limited to the preset power threshold A within the first preset time, and the charging power of the power battery is directly limited to 0.

4. The method for treating the damaged bottom of a battery module in a power battery according to claim 1, characterized in that: If the number n of battery modules with damaged bottoms in the power battery is greater than or equal to a preset first number threshold, and the vehicle is in driving state, and the vehicle speed is greater than the preset vehicle speed threshold, it is determined to be an N+2 level fault, and a request is made to light up the dashboard fault light and request voice and text prompts to smoothly limit the discharge power of the power battery to 0 within the first preset time, and directly limit the charging power of the power battery to 0.

5. The method for treating the damaged bottom of a battery module in a power battery according to claim 3 or 4, characterized in that: The preset first quantity threshold is 2, the preset vehicle speed threshold is 15 km / h, and the first preset time is 1 minute.

6. The method for treating the damaged bottom of a battery module in a power battery according to any one of claims 1 to 4, characterized in that: If the absolute value of the difference between the measured resistance value of a certain resistance strain gauge and the standard resistance value of the resistance strain gauge is less than or equal to a preset resistance threshold, it is determined that the battery module corresponding to the resistance strain gauge has no bottom damage.

7. The method for treating the damaged bottom of a battery module in a power battery according to claim 6, characterized in that: The preset resistance threshold is 2Ω.

8. A system for processing damaged bottom of battery module in power battery, characterized in that: It includes a battery management system, a data acquisition and processing module and m resistance strain gauges, the m resistance strain gauges are respectively pasted on the bottom of m battery modules, the area of ​​each resistance strain gauge is equal to the area of ​​the bottom of each battery module, and the m resistance strain gauges are connected to the battery management system through the data acquisition and processing module; the battery management system is programmed to execute the processing method as described in any one of claims 1 to 7.

9. A vehicle, characterized in that: Comprising the processing system of claim 8.

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