A method, system and vehicle for processing abnormal power battery temperature acquisition

Abstract

The present invention discloses a processing method, system and vehicle for abnormal power battery temperature acquisition. When the power battery temperature acquisition is abnormal, according to the temperature acquisition abnormal fault type and the state of the vehicle, a fault prompt is requested, and the charging power and / or discharging power of the power battery is processed. When the power battery needs to be used continuously but there is a risk of thermal runaway, the vehicle water cooling cycle is requested to be turned on to continuously cool the power battery, and the smoke sensor signal inside the power battery is monitored at the same time. When thermal runaway occurs, a thermal runaway alarm signal is immediately issued. Thus, the impact and harm of abnormal power battery temperature acquisition on drivers and passengers can be reduced as much as possible.

Description

Technical Field

[0001] The present invention belongs to the field of new energy vehicle power batteries, and specifically relates to a method, system and vehicle for processing abnormal power battery temperature acquisition. Background Art

[0002] Changes in ambient temperature will affect the charging and discharging performance of the battery. Too low a temperature will cause the active materials in the power battery to decrease, resulting in a decrease in the discharge capacity of the power battery, so that the rated cruising range of the electric vehicle is reduced. Too high a temperature will affect the life of the power battery, and it is necessary to prevent safety problems with the power battery. In order to monitor the temperature of the power battery, multiple sampling points will be selected in each battery module in the power battery, and a temperature sensor will be arranged at each sampling point to collect the temperature of the corresponding battery module in real time. The temperature collected by the temperature sensor is sent to the battery management system (ie BMS), which determines whether the temperature collection is abnormal and performs corresponding processing. When the temperature collection is abnormal due to the failure of the temperature sensor, the collected battery temperature data will be unreliable. At this time, how the battery management system can correctly and effectively handle the current situation is currently an important research topic. Summary of the invention

[0003] The purpose of the present invention is to provide a method, system and vehicle for processing abnormal power battery temperature acquisition, so as to reduce the impact and harm of abnormal power battery temperature acquisition on drivers and passengers as much as possible.

[0004] The method for handling abnormal temperature acquisition of a power battery described in the present invention is: according to the type of abnormal temperature acquisition fault and the state of the vehicle, request a fault prompt, and process the charging power and / or discharging power of the power battery; when the power battery needs to continue to be used but there is a risk of thermal runaway, request to open the vehicle water cooling cycle to continuously cool the power battery, and at the same time monitor the smoke sensor signal inside the power battery. When thermal runaway occurs, immediately issue a thermal runaway alarm signal.

[0005] Preferably, if only the temperature sensors of some sampling points in each battery module in the power battery fail, it is determined to be a temperature acquisition abnormality Type A fault; when the temperature acquisition abnormality Type A fault occurs, if the vehicle is in a stationary charging state or a stationary discharging state or a driving state, it is requested to light up the instrument panel fault light, and there is no restriction on the charging power and discharging power of the power battery.

[0006] Preferably, if there is a battery module in the power battery whose temperature sensors at all sampling points have failed, and the number n of battery modules whose temperature sensors at all sampling points have failed is less than or equal to a preset number threshold M (i.e. 1≤n≤M), it is determined to be a temperature acquisition abnormality Class B fault.

[0007] When the temperature collection abnormality Class B fault occurs, if the vehicle is in a stationary charging state, a request is made to light up the instrument panel fault light and a voice prompt is requested. The discharge power of the power battery is not restricted, and the charging power of the power battery is directly limited to the preset first power threshold Y. A request is made to open the vehicle water cooling cycle to continuously cool the power battery. At the same time, the smoke sensor signal inside the power battery is monitored. When a thermal runaway occurs, a thermal runaway alarm signal is immediately issued.

[0008] When the temperature collection abnormality Class B fault occurs, if the vehicle is in a static discharge state, a request is made to light up the instrument panel fault light and a voice prompt is requested, the discharge power of the power battery is directly limited to the preset second power threshold X, the charging power of the power battery is directly limited to 0, and a request is made to turn on the vehicle water cooling cycle to continuously cool the power battery. At the same time, the smoke sensor signal inside the power battery is monitored. When a thermal runaway occurs, a thermal runaway alarm signal is immediately issued.

[0009] When the temperature collection abnormality Class B fault occurs, if the vehicle is in driving state, request to light up the instrument panel fault light and request voice prompt, do not limit the discharge power of the power battery, directly limit the charging power of the power battery to 0, request to open the vehicle water cooling cycle to continuously cool the power battery, and monitor the smoke sensor signal inside the power battery at the same time. When thermal runaway occurs, immediately issue a thermal runaway alarm signal.

[0010] Preferably, when thermal runaway occurs, the discharge power of the power battery is smoothly limited to 0 within a first preset time, and the charging power of the power battery is directly limited to 0.

[0011] Preferably, if there is a battery module in the power battery whose temperature sensors at all sampling points have failed, and the number n of battery modules whose temperature sensors at all sampling points have failed is greater than a preset number threshold M (ie n>M), it is determined to be a temperature acquisition abnormality Class C fault.

[0012] When the temperature collection abnormality Class C fault occurs, if the vehicle is in a stationary charging state or a stationary discharging state, a request is made to light up the instrument panel fault light and request a voice prompt, and within the second preset time, the discharge power of the power battery is smoothly limited to 0, and the charging power of the power battery is directly limited to 0, and the charge and discharge handshake signal is disconnected.

[0013] When the temperature collection abnormality Class C fault occurs, if the vehicle is in driving state, a request is made to light up the instrument panel fault light and request a voice prompt, 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.

[0014] The processing system for abnormal power battery temperature acquisition of the present invention includes a battery management system, and the battery management system is programmed to execute the above processing method.

[0015] The vehicle of the present invention comprises the above-mentioned processing system.

[0016] The present invention has the following effects:

[0017] When the power battery temperature acquisition is abnormal, according to the temperature acquisition abnormal fault type (corresponding to the severity) and the state of the vehicle, request a fault prompt, and process the charging power and / or discharging power of the power battery (i.e. limit or not limit). In the case where the power battery needs to continue to be used but there is a risk of thermal runaway, request to open the vehicle water cooling cycle to continuously cool the power battery, and monitor the smoke sensor signal inside the power battery at the same time. When thermal runaway occurs, immediately issue a thermal runaway alarm signal. In this way, under the premise of ensuring the safe use of the power battery, the power battery is kept in the best working state to the greatest extent, and the handling method is more reasonable; and the impact and harm of abnormal power battery temperature acquisition on drivers and passengers is also reduced as much as possible. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic diagram of the classification of abnormal temperature acquisition failure types in this embodiment.

[0019] Figure 2 It is the vehicle-level safety target set in this embodiment.

[0020] Figure 3 This is a flow chart of the processing method when the power battery temperature acquisition is abnormal in this embodiment. DETAILED DESCRIPTION

[0021] The power battery is composed of multiple battery modules, and a battery module has multiple single cells. In order to monitor the temperature of the power battery, multiple sampling points will be selected in each battery module in the power battery, and a temperature sensor will be arranged at each sampling point to collect the temperature of the corresponding battery module in real time. The temperature collected by the temperature sensor is sent to the battery management system (i.e., BMS), and the battery management system judges the temperature collection abnormality (its judgment method belongs to the existing technology) and performs corresponding processing. During the temperature collection process, temperature collection abnormalities may occur. The reasons for temperature collection abnormalities usually include: open circuit failure of the temperature sensor, short circuit failure of the temperature sensor to the power supply, short circuit failure of the temperature sensor to the ground, and rationality failure of the temperature collection data, which can be collectively referred to as "temperature sensor failure". Due to abnormal temperature collection, the internal temperature of the battery module cannot be monitored, thereby affecting other normal operating functions; for example, during the operation of the vehicle, the driver causes high-power discharge of the power battery under intense driving conditions, and the thermal management system of the vehicle cannot heat or cool the power battery based on the effective battery temperature data, so that the vehicle has uncertain risks during operation, and in severe cases, it may cause thermal runaway of the vehicle. This embodiment is precisely for processing temperature collection abnormalities to ensure the safe charging and discharging of the power battery, meeting the following requirements: Figure 2 Vehicle-level safety targets are shown.

[0022] like Figure 1 As shown, in this embodiment, the temperature acquisition abnormality fault types are divided into three categories, specifically: temperature acquisition abnormality type A fault, temperature acquisition abnormality type B fault and temperature acquisition abnormality type C fault. The fault in which only some of the temperature sensors at the sampling points in each battery module in the power battery fail is classified as temperature acquisition abnormality type A fault. The fault in which the temperature sensors at all sampling points in the power battery fail, and the number of battery modules at which the temperature sensors at all sampling points fail is less than or equal to the preset number threshold M (that is, the number of battery modules at which the temperature sensors at all sampling points in the power battery fail satisfies: 1≤n≤M), is classified as temperature acquisition abnormality type B fault. The fault in which the temperature sensors at all sampling points in the power battery fail, and the number of battery modules at which the temperature sensors at all sampling points fail is greater than the preset number threshold M (that is, the number of battery modules at which the temperature sensors at all sampling points in the power battery fail satisfies: n>M), is classified as temperature acquisition abnormality type C fault.

[0023] In this embodiment, there are three states of the vehicle, specifically: the first state, the vehicle is in a stationary charging state; the second state, the vehicle is in a stationary discharging state; the third state, the vehicle is in a driving state. If the charging gun is plugged in, the charge and discharge handshake signal is established, and the vehicle speed is equal to 0, it means that the vehicle is in a stationary charging state. If the discharge gun is plugged in, the charge and discharge handshake signal is established, and the vehicle speed is equal to 0, it means that the vehicle is in a stationary discharging state. If the vehicle speed is greater than 0, it means that the vehicle is in a driving state.

[0024] like Figure 3 As shown, in this embodiment, the processing method when the power battery temperature collection is abnormal is executed by the battery management system, and the processing method includes:

[0025] Step 1: Determine whether a temperature acquisition abnormality type A fault occurs. If yes, proceed to step 2; otherwise, proceed to step 4.

[0026] Step 2: Determine whether the vehicle is in a stationary charging state, a stationary discharging state, or a driving state. If yes, execute step 3, otherwise end.

[0027] Step 3: Execute strategy 1, and then end. Strategy 1 specifically includes: requesting the instrument panel fault light to be turned on (to inform the driver that a fault has occurred), and not limiting the charging power and discharging power of the power battery.

[0028] When a temperature acquisition abnormality type A fault occurs, the temperature sensors at some sampling points in each battery module are still intact and capable of temperature detection, which can meet the vehicle-level safety goals of target 1 and target 2. Therefore, there is no limit on the charging power and discharging power of the power battery. If the vehicle is in driving state, the current driving cycle can be restored.

[0029] Step 4: Determine whether a temperature acquisition abnormality Class B fault occurs. If so, proceed to step 5; otherwise, proceed to step 11.

[0030] Step 5: Determine whether the vehicle is in a stationary charging state. If so, proceed to step 6; otherwise, proceed to step 7.

[0031] Step 6: Execute Strategy 2, and then end. Strategy 2 specifically includes: requesting to light up the instrument panel fault light and requesting a voice prompt (informing the driver that a fault has occurred), not limiting the discharge power of the power battery, directly limiting the charging power of the power battery to the preset first power threshold Y, requesting to open the vehicle water cooling cycle to continuously cool the power battery, and monitoring the smoke sensor signal inside the power battery. When a thermal runaway occurs, a thermal runaway alarm signal is immediately issued, and the discharge power of the power battery is smoothly limited to 0 within the first preset time (for example, 30s), and the charging power of the power battery is directly limited to 0.

[0032] The vehicle is in a static charging state. When a temperature acquisition abnormality Class B fault occurs, the battery management system cannot effectively monitor the temperature of the battery module where the temperature sensors of all sampling points have failed, but the temperature of the remaining battery modules can still be monitored. The number n of battery modules where the temperature sensors of all sampling points have failed is small, and the power battery will have a risk of thermal runaway if used for a long time. However, in order to meet the goals 1 and 2 of the vehicle-level safety goals, the discharge power of the power battery is not limited, and the charging power of the power battery is directly limited to the preset first power threshold Y. The trickle charging method is used to reduce the charging current and charging speed, reduce the heating of the battery module during the charging process, and request to open the vehicle water cooling cycle to continuously cool the power battery, and monitor the smoke sensor signal inside the power battery. When a thermal runaway occurs, a thermal runaway alarm signal is immediately issued, 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. The thermal runaway alarm signal can be transmitted to the backend through the vehicle computer. The backend locates the vehicle through big data and contacts the fire department to rush to the scene for immediate disposal. The backend customer service staff can also call the driver for emergency disposal and evacuation guidance.

[0033] Step 7: Determine whether the vehicle is in a stationary discharge state. If yes, execute step 8; otherwise, execute step 9.

[0034] Step 8, execute strategy 3, and then end. Strategy 3 specifically includes: requesting to light up the instrument panel fault light and requesting voice prompt (informing the driver that a fault has occurred), directly limiting the discharge power of the power battery to the preset second power threshold X, directly limiting the charging power of the power battery to 0, requesting to open the vehicle water cooling cycle to continuously cool the power battery, and monitoring the smoke sensor signal inside the power battery at the same time. When a thermal runaway occurs, a thermal runaway alarm signal is immediately issued, and the discharge power of the power battery is smoothly limited to 0 within the first preset time (for example, 30s).

[0035] The vehicle is in a static discharge state. When a temperature acquisition abnormality Class B fault occurs, the battery management system cannot effectively monitor the temperature of the battery module where the temperature sensors of all sampling points have failed, but the temperature of the remaining battery modules can still be monitored. The number n of battery modules where the temperature sensors of all sampling points have failed is small, and the long-term use of the power battery will cause thermal runaway risks. However, in order to meet the goals 1 and 2 of the vehicle-level safety goals, the discharge power of the power battery is directly limited to the preset second power threshold X, and the charging power of the power battery is directly limited to 0. The trickle discharge method is used to reduce the discharge current and discharge speed, reduce the heat generation of the battery module during the discharge process, and request to open the vehicle water cooling cycle to continuously cool the power battery, and monitor the smoke sensor signal inside the power battery. When a thermal runaway occurs, a thermal runaway alarm signal is immediately issued, and the discharge power of the power battery is smoothly limited to 0 within the first preset time. The charging power of the power battery has been limited to 0 before, and it will not be described here. The thermal runaway alarm signal can be transmitted to the backend through the vehicle computer. The backend locates the vehicle through big data and contacts the fire department to rush to the scene for immediate disposal. The backend customer service staff can also call the driver for emergency disposal and evacuation guidance.

[0036] Step 9: Determine whether the vehicle is in driving state, if yes, execute step 10, otherwise end.

[0037] Step 10, execute strategy 4, and then end. Strategy 4 is specifically: request to light up the instrument panel fault light and request voice prompt (to inform the driver that a fault has occurred), do not limit the discharge power of the power battery, directly limit the charging power of the power battery to 0, request to open the vehicle water cooling cycle to continuously cool the power battery, and monitor the smoke sensor signal inside the power battery. When a thermal runaway occurs, immediately send a thermal runaway alarm signal, and smoothly limit the discharge power of the power battery to 0 within the first preset time (such as 30s).

[0038] When the vehicle is in driving state and a temperature collection abnormality Class B fault occurs, the battery management system cannot effectively monitor the temperature of the battery module where the temperature sensors of all sampling points have failed, but the temperature of the remaining battery modules can still be monitored. The number of battery modules where the temperature sensors of all sampling points have failed is small, and the long-term use of the power battery will generate the risk of thermal runaway. However, in order to meet the goals 1 and 2 of the vehicle-level safety goals, the discharge power of the power battery is not limited, and the charging power of the power battery is directly limited to 0. It is considered that the current driving cycle is unrecoverable. At the same time, it is requested to open the vehicle water cooling cycle to continuously cool the power battery, and monitor the smoke sensor signal inside the power battery. When a thermal runaway occurs, a thermal runaway alarm signal is immediately issued, 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. The thermal runaway alarm signal can be transmitted to the background through the vehicle computer. The background locates the vehicle position through big data, and contacts the fire department to rush to the scene for disposal as soon as possible. The background customer service staff can also call the driver for emergency disposal and guide evacuation.

[0039] Step 11: Determine whether a temperature acquisition abnormality C fault occurs. If yes, proceed to step 12, otherwise end.

[0040] Step 12: Determine whether the vehicle is in a stationary charging state or a stationary discharging state. If yes, execute step 13; otherwise, execute step 14.

[0041] Step 13, execute strategy 5, and then end. Strategy 5 is specifically: request to light up the instrument panel fault light and request voice prompt (to inform the driver that a fault has occurred), smoothly limit the discharge power of the power battery to 0 within a second preset time (such as 1 minute), directly limit the charging power of the power battery to 0, and disconnect the charge and discharge handshake signal.

[0042] When the vehicle is in a static charging state or a static discharging state, and a temperature acquisition abnormality type C fault occurs, the battery management system cannot effectively monitor the temperature of the battery module where the temperature sensors of all sampling points have failed, but the temperature of the remaining battery modules can still be monitored. The number of battery modules where the temperature sensors of all sampling points have failed is large. In this case, the exposure (describes the probability of personnel being exposed to a scene where failure can cause harm when the danger occurs) and severity (describes the degree of harm that the danger may cause to the driver, passengers, or pedestrians) increase. It is necessary to increase the controllability (describes the possibility that the driver or other personnel at risk can avoid accidents or injuries through timely response when the danger occurs) to reduce the risk of thermal runaway. In order to ensure that the driver can drive the vehicle to a safe area in a short time, it is necessary to smoothly limit the discharge power of the power battery to 0 within the second preset time, directly limit the charging power of the power battery to 0, disconnect the charge and discharge handshake signal, make the charge and discharge cycle irreversible, and prohibit charging and discharging.

[0043] Step 14: Determine whether the vehicle is in driving state. If yes, execute step 15, otherwise end.

[0044] Step 15, execute strategy 6, and then end. Strategy 6 specifically includes: requesting to light up the instrument panel fault light and requesting a voice prompt (to inform the driver that a fault has occurred), smoothly limiting the discharge power of the power battery to 0 within a first preset time (such as 30 seconds), and directly limiting the charging power of the power battery to 0.

[0045] When the vehicle is in driving state and a temperature collection abnormality C fault occurs, the battery management system cannot effectively monitor the temperature of the battery module where the temperature sensors of all sampling points have failed, but the temperature of the remaining battery modules can still be monitored. The number n of battery modules where the temperature sensors of all sampling points have failed is large, and the exposure and severity of this situation increase. It is necessary to increase the controllability to reduce the risk of thermal runaway. Therefore, 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. The current driving cycle cannot be restored.

[0046] The processing system for abnormal power battery temperature acquisition in this embodiment includes a battery management system, which is programmed to execute the processing method for abnormal power battery temperature acquisition.

[0047] The vehicle in this embodiment includes the above-mentioned power battery temperature acquisition abnormality processing system.

Claims

1. A method for processing abnormal power battery temperature acquisition, characterized in that: The method is as follows: according to the temperature acquisition abnormality fault type and the state of the vehicle, request a fault prompt, and process the charging power and / or discharging power of the power battery; if there is a battery module in the power battery whose temperature sensors at all sampling points have failed, and the number n of the battery modules is less than or equal to a preset number threshold M, it is determined to be a temperature acquisition abnormality type B fault; when the temperature acquisition abnormality type B fault occurs, if the vehicle is in a stationary charging state, request to light up the instrument panel fault light and request a voice prompt, do not limit the discharge power of the power battery, directly limit the charging power of the power battery to a preset first power threshold Y, request to open the vehicle water cooling cycle to continuously cool the power battery, and monitor the smoke sensor signal inside the power battery at the same time. When thermal runaway occurs, a thermal runaway alarm signal is immediately issued.

2. The method for processing abnormal power battery temperature acquisition according to claim 1, characterized in that: When the temperature collection abnormality Class B fault occurs, if the vehicle is in a static discharge state, a request is made to light up the instrument panel fault light and a voice prompt is requested, the discharge power of the power battery is directly limited to the preset second power threshold X, the charging power of the power battery is directly limited to 0, and a request is made to turn on the vehicle water cooling cycle to continuously cool the power battery. At the same time, the smoke sensor signal inside the power battery is monitored. When a thermal runaway occurs, a thermal runaway alarm signal is immediately issued.

3. The method for processing abnormal power battery temperature acquisition according to claim 1, characterized in that: When the temperature collection abnormality Class B fault occurs, if the vehicle is in driving state, request to light up the instrument panel fault light and request voice prompt, do not limit the discharge power of the power battery, directly limit the charging power of the power battery to 0, request to open the vehicle water cooling cycle to continuously cool the power battery, and monitor the smoke sensor signal inside the power battery at the same time. When thermal runaway occurs, immediately issue a thermal runaway alarm signal.

4. The method for processing abnormal power battery temperature acquisition according to any one of claims 1 to 3, characterized in that: If only some of the temperature sensors at the sampling points in each battery module of the power battery fail, it is determined to be a temperature acquisition abnormality Class A fault; when the temperature acquisition abnormality Class A fault occurs, if the vehicle is in a stationary charging state, a stationary discharging state, or a driving state, the instrument panel fault light is requested to be turned on, and the charging power and discharging power of the power battery are not restricted.

5. The method for processing abnormal power battery temperature acquisition according to any one of claims 1 to 3, characterized in that: When thermal runaway occurs, the discharge power of the power battery is smoothly limited to 0 within a first preset time, and the charging power of the power battery is directly limited to 0.

6. The method for processing abnormal power battery temperature acquisition according to claim 5, characterized in that: If there is a battery module in the power battery whose temperature sensors at all sampling points have failed, and the number n of such battery modules is greater than the preset number threshold M, it is determined to be a temperature acquisition abnormality Type C fault; when the temperature acquisition abnormality Type C fault occurs, if the vehicle is in a stationary charging state or a stationary discharging state, a request is made to light up the instrument panel fault light and request a voice prompt, and within a second preset time, the discharge power of the power battery is smoothly limited to 0, and the charging power of the power battery is directly limited to 0, and the charge and discharge handshake signal is disconnected.

7. The method for processing abnormal power battery temperature acquisition according to claim 5, characterized in that: If there is a battery module in the power battery whose temperature sensors at all sampling points have failed, and the number n of such battery modules is greater than the preset number threshold M, it is determined to be a temperature acquisition abnormality Type C fault; when the temperature acquisition abnormality Type C fault occurs, if the vehicle is in driving state, a request is made to light up the instrument panel fault light and request a voice prompt, 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.

8. A processing system for abnormal power battery temperature acquisition, including a battery management system, characterized in that: The battery management system is programmed to execute the processing method according to any one of claims 1 to 7.

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

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