Power battery safety early warning method based on voltage and temperature signal fusion

Abstract

The invention relates to the technical field of Internet of Vehicles big data analysis, and discloses a power battery safety early warning method based on voltage and temperature signal fusion, and the method comprises the steps: obtaining a single voltage sequence of a power battery, and determining an overvoltage risk early warning level and an over-discharge risk early warning level of the power battery based on the single voltage sequence; obtaining a monomer temperature sequence of the power battery, and determining a range risk early warning level of the power battery based on the monomer voltage sequence and the monomer temperature sequence; the method comprises the steps of determining an early warning score based on a safety early warning level triggered by the power battery, and generating a risk level of the power battery based on the early warning score, and the safety early warning level comprises one or a combination of more of the following early warning levels: an overvoltage risk early warning level, an over-discharge risk early warning level and a range risk early warning level. The voltage and temperature signals of the power battery are monitored at the same time, battery system thermal runaway risk perception and early warning are achieved, and misjudgment or missed judgment possibly caused by single signal monitoring can be avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicle networking big data analysis, and in particular to a method for power battery safety early warning based on voltage and temperature signal fusion. Background Art

[0002] In related technologies, the inconsistency of single cells can be perceived using a model-driven method based on Internet of Vehicles data, and the power battery safety risk warning can be achieved by comparing the consistency index with the set threshold conditions. In related technologies, the power battery safety risk warning is mainly carried out from the perspective of single cell voltage consistency. Specific methods include statistical methods such as entropy model, volatility model, voltage drop model, correlation model, etc.

[0003] The related technology of evaluating battery safety risk scenarios based on single cell voltage consistency has certain limitations. Summary of the invention

[0004] In view of this, the present invention provides a method for power battery safety warning based on the fusion of voltage and temperature signals to solve the problem that the related art has certain limitations in evaluating battery safety risk scenarios based on single cell voltage consistency.

[0005] In a first aspect, the present invention provides a method for power battery safety warning based on the fusion of voltage and temperature signals, the method comprising: obtaining a single cell voltage sequence of the power battery, and determining an overvoltage risk warning level and an over-discharge risk warning level of the power battery based on the single cell voltage sequence; obtaining a single cell temperature sequence of the power battery, and determining an extreme risk warning level of the power battery based on the single cell voltage sequence and the single cell temperature sequence; determining a warning score based on the safety warning level triggered by the power battery, and generating a risk level of the power battery based on the warning score, wherein the safety warning level includes one or a combination of the following warning levels: an overvoltage risk warning level, an over-discharge risk warning level, and an extreme risk warning level.

[0006] In an optional embodiment, a cell temperature sequence of a power battery is obtained, and an extreme risk warning level of the power battery is determined based on a cell voltage sequence and a cell temperature sequence, including: determining a difference between a maximum cell voltage and a minimum cell voltage of the power battery, the maximum voltage value in the cell voltage sequence being the maximum cell voltage, and the minimum voltage value in the cell voltage sequence being the minimum cell voltage; if the difference is greater than or equal to a pressure difference threshold, and the maximum temperature value in the cell temperature sequence is greater than or equal to a preset temperature threshold for a preset frame length, the extreme risk warning level of the power battery is determined to be level two; or, if the difference is greater than or equal to a pressure difference threshold, and the maximum temperature value in the cell temperature sequence is greater than or equal to a preset temperature threshold for a preset time length, the extreme risk warning level of the power battery is determined to be level two.

[0007] In an optional embodiment, a warning score is determined based on the safety warning level triggered by the power battery, including: determining the highest level among the safety warning levels triggered by the power battery, and determining a basic warning score based on the highest level; determining the number of target levels in the safety warning levels triggered by the power battery, determining an upward coefficient corresponding to the target level, and generating a warning upward score for the target level based on the product of the warning basic score, the upward coefficient corresponding to the target level, and the number of target levels; determining a warning score based on the sum of the warning basic score and the warning upward scores of each level.

[0008] In an optional embodiment, based on the warning score, a risk level of the power battery is generated, including: if the warning score is zero, the generated risk level of the power battery is safe; if the warning score is greater than or equal to the first warning threshold, and the warning score is less than the second warning threshold, the generated risk level of the power battery is the first risk level; if the warning score is greater than or equal to the second warning threshold, and the warning score is less than the third warning threshold, the generated risk level of the power battery is the second risk level; if the warning score is greater than or equal to the third warning threshold, the generated risk level of the power battery is the third risk level.

[0009] In an optional embodiment, based on the single cell voltage sequence, the overvoltage risk warning level and the over-discharge risk warning level of the power battery are determined, including: determining the overvoltage threshold based on the single cell operating voltage upper limit, the first over-limit voltage threshold and the second over-limit voltage threshold of the power battery; if the maximum value of the voltage value in the single cell voltage sequence is greater than or equal to the overvoltage threshold for a preset frame length, or if the maximum value of the voltage value in the single cell voltage sequence is greater than or equal to the overvoltage threshold for a preset time length, the overvoltage risk warning level of the power battery is determined to be level two.

[0010] In an optional embodiment, based on the single cell voltage sequence, determining the overvoltage risk warning level and over-discharge risk warning level of the power battery also includes: determining the over-discharge threshold based on the single cell operating voltage lower limit, the third over-limit voltage threshold and the fourth over-limit voltage threshold of the power battery; if the minimum value of the voltage value in the single cell voltage sequence is less than or equal to the over-discharge threshold for a preset frame length, or if the minimum value of the voltage value in the single cell voltage sequence is less than or equal to the over-discharge threshold for a preset time length, determining that the over-discharge risk warning level of the power battery is level two.

[0011] In a second aspect, the present invention provides a device for power battery safety warning based on the fusion of voltage and temperature signals, the device comprising: a first acquisition module, used to obtain the single cell voltage sequence of the power battery, and determine the overvoltage risk warning level and over-discharge risk warning level of the power battery based on the single cell voltage sequence; a second acquisition module, used to obtain the single cell temperature sequence of the power battery, and determine the extreme risk warning level of the power battery based on the single cell voltage sequence and the single cell temperature sequence; a warning module, used to determine the warning score based on the safety warning level triggered by the power battery, and generate the risk level of the power battery based on the warning score, wherein the safety warning level includes one or a combination of the following warning levels: overvoltage risk warning level, over-discharge risk warning level and extreme risk warning level.

[0012] In a third aspect, the present invention provides a computer device, comprising: a memory and a processor, the memory and the processor are communicatively connected to each other, the memory stores computer instructions, and the processor executes the method for power battery safety warning based on voltage and temperature signal fusion of the above-mentioned first aspect or any corresponding embodiment thereof by executing the computer instructions.

[0013] In a fourth aspect, the present invention provides a computer-readable storage medium having computer instructions stored thereon, the computer instructions being used to enable a computer to execute the method for power battery safety warning based on the fusion of voltage and temperature signals of the above-mentioned first aspect or any corresponding embodiment thereof.

[0014] In a fifth aspect, the present invention provides a computer program product, comprising computer instructions, which are used to enable a computer to execute the method for power battery safety warning based on voltage and temperature signal fusion of the above-mentioned first aspect or any corresponding embodiment thereof.

[0015] The method for power battery safety early warning based on voltage and temperature signal fusion provided by the present invention performs safety early warning of power batteries according to the evolution path of thermal runaway failure scenarios and in combination with analysis of a historical thermal runaway occurrence feature database. By simultaneously monitoring the voltage and temperature signals of the power battery, thermal runaway risk perception and early warning of the battery system are realized, and the safety status of the power battery can be evaluated more comprehensively, avoiding misjudgment or missed judgment that may be caused by single signal monitoring, and improving the accuracy and reliability of the early warning. The safety early warning level is divided into an overvoltage risk early warning level, an over-discharge risk early warning level, and an extreme risk early warning level, etc., so that different risk types of the battery can be more accurately identified, and targeted countermeasures can be taken. By obtaining the single cell voltage sequence and the single cell sequence of the power battery, the safety status of the power battery can be dynamically evaluated, potential risks can be discovered in time, and the battery can be prevented from continuing to work in an abnormal state. By converting different early warning levels into early warning scores, the safety risk of the battery can be quantified, which is convenient for intuitively judging the overall safety status of the battery. By early warning of risks such as overvoltage, over-discharge and extreme difference of the battery, the occurrence of risk situations such as overheating, overcharging or over-discharging of the battery can be effectively prevented, and the battery life can be extended and safety protection can be provided for the use of the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the related technologies, the drawings required for use in the specific embodiments or the related technical descriptions will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0017] Figure 1 A schematic flow chart showing a method for power battery safety early warning based on voltage and temperature signal fusion according to an embodiment of the present invention is shown;

[0018] Figure 2 A schematic flow chart showing another method for power battery safety early warning based on voltage and temperature signal fusion according to an embodiment of the present invention;

[0019] Figure 3 A schematic diagram showing the structure of a power battery safety warning device based on voltage and temperature signal fusion according to an embodiment of the present invention;

[0020] Figure 4 It is a schematic diagram of the hardware structure of a computer device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0022] Thermal runaway of power battery systems is one of the most harmful and influential failure modes of energy storage systems, restricting the development and application of new energy vehicles.

[0023] According to an embodiment of the present invention, a method embodiment of power battery safety warning based on voltage and temperature signal fusion is provided. It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and although the logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0024] In this embodiment, a method for power battery safety warning based on voltage and temperature signal fusion is provided, which can be used in the above-mentioned mobile terminals, such as mobile phones, tablet computers, desktop computers, servers or vehicle intelligent cockpits, etc. Figure 1 FIG. 1 is a flow chart showing a method for power battery safety early warning based on voltage and temperature signal fusion according to an embodiment of the present invention. Figure 1 As shown, the process includes the following steps:

[0025] Step S101 : obtaining a cell voltage sequence of a power battery, and determining an overvoltage risk warning level and an over-discharge risk warning level of the power battery based on the cell voltage sequence.

[0026] In this step, the power battery is the power source for the tool and is the core component of new energy vehicles. The power battery is different from the starting battery for starting the car engine. It can be a valve-sealed lead-acid battery, an open-type tubular lead-acid battery, and a lithium iron phosphate battery.

[0027] The battery management system can collect the single cell voltage data of the power battery to form a voltage sequence. The overvoltage threshold can be set, and the voltage sequence can be traversed based on the overvoltage threshold to determine whether there is a single cell voltage exceeding the overvoltage threshold. According to the degree and time of exceeding the overvoltage threshold, the overvoltage risk warning level is determined. Among them, the overvoltage threshold can be provided by the battery manufacturer or determined according to the battery characteristics.

[0028] Similarly, an over-discharge threshold can be set. Based on the over-discharge threshold, the voltage sequence can be traversed to determine whether there is a single cell voltage lower than the over-discharge threshold. According to the degree and time of being lower than the over-discharge threshold, the over-discharge risk warning level can be determined. The over-discharge threshold can also be provided by the battery manufacturer or determined according to the battery characteristics.

[0029] Step S102 : acquiring a cell temperature sequence of the power battery, and determining a critical risk warning level of the power battery based on the cell voltage sequence and the cell temperature sequence.

[0030] In this step, the battery management system can be used to collect the temperature sequence of the power battery cells. The voltage range can be calculated, and the voltage range can be obtained by subtracting the minimum voltage from the maximum voltage. A voltage difference threshold can be set to determine whether there is a voltage range higher than the voltage difference threshold. The voltage difference risk warning level can be determined based on the degree and time of the voltage range higher than the voltage difference threshold. The voltage difference threshold can be provided by the battery manufacturer or determined based on the battery characteristics.

[0031] Step S103, based on the safety warning level triggered by the power battery, determine the warning score, and based on the warning score, generate the risk level of the power battery, wherein the safety warning level includes one or a combination of the following warning levels: overvoltage risk warning level, over-discharge risk warning level and extreme risk warning level.

[0032] In this step, the overvoltage risk warning level can be quantified into a warning score according to the severity of the overvoltage risk. For example, the overvoltage risk warning level of the power battery is level 2, and the quantified level 2 overvoltage score can be 2.5 points. The specific score value can be set according to the actual application scenario. Similarly, the over-discharge risk warning level and the extreme risk warning level can be quantified. Weights can be assigned to the over-discharge risk warning level, the over-discharge risk warning level, and the extreme risk warning level, and the warning score can be calculated using the weighted sum formula. According to the range of the warning score, the risk level of the power battery can be divided.

[0033] The method for power battery safety warning based on voltage and temperature signal fusion provided in this embodiment performs safety warning of power battery according to the evolution path of thermal runaway failure scenario and in combination with analysis of historical thermal runaway occurrence feature database. By simultaneously monitoring the voltage and temperature signals of the power battery, thermal runaway risk perception and warning of the battery system are realized, and the safety status of the power battery can be evaluated more comprehensively, avoiding misjudgment or missed judgment that may be caused by single signal monitoring, and improving the accuracy and reliability of the warning. The safety warning level is divided into overvoltage risk warning level, over-discharge risk warning level and extreme risk warning level, etc., which can more accurately identify different risk types of the battery and facilitate targeted response measures. By obtaining the single cell voltage sequence and single cell sequence of the power battery, the safety status of the power battery can be dynamically evaluated, potential risks can be discovered in time, and the battery can be prevented from continuing to work in an abnormal state. By converting different warning levels into warning scores, the safety risk of the battery can be quantified, which is convenient for intuitively judging the overall safety status of the battery. By early warning of risks such as overvoltage, over-discharge and extreme difference of the battery, the occurrence of risk situations such as overheating, overcharging or over-discharge of the battery can be effectively prevented, and the battery life can be extended and safety protection can be provided for the use of the battery.

[0034] In this embodiment, a method for power battery safety warning based on voltage and temperature signal fusion is provided, which can be used in the above-mentioned mobile terminals, such as mobile phones, tablet computers, desktop computers, servers or vehicle intelligent cockpits, etc. Figure 2 FIG. 1 is a flow chart showing another method for power battery safety warning based on voltage and temperature signal fusion according to an embodiment of the present invention. Figure 2 As shown, the process includes the following steps:

[0035] Step S201, obtaining the cell voltage sequence of the power battery, and determining the overvoltage risk warning level and over-discharge risk warning level of the power battery based on the cell voltage sequence. Figure 1 Step S101 of the illustrated embodiment will not be described in detail here.

[0036] Step S202 : acquiring a cell temperature sequence of the power battery, and determining a critical risk warning level of the power battery based on the cell voltage sequence and the cell temperature sequence.

[0037] Specifically, the above step S202 includes:

[0038] Step S2021, determining the difference between the maximum value and the minimum value of the power battery cell voltage, the maximum value of the voltage in the cell voltage sequence is the maximum value of the cell voltage, and the minimum value of the voltage in the cell voltage sequence is the minimum value of the cell voltage.

[0039] ΔCellV can be used to represent the difference between the maximum value and the minimum value of the power battery cell voltage, and V1 can be used to represent the voltage difference threshold. If ΔCellV ≥ V1, and the preset frame length or the preset duration is continued, the extreme risk warning level of the power battery is determined to be level 1. The extreme risk warning level of the power battery can be reported.

[0040] Step S2022: If the difference is greater than or equal to the pressure difference threshold, and the maximum value of the temperature value in the cell temperature sequence is greater than or equal to the preset temperature threshold for a preset frame length, the extreme risk warning level of the power battery is determined to be level 2.

[0041] In this step, you can use CellT max Indicates the maximum temperature value in the power battery cell temperature sequence, using T max Indicates the upper temperature limit of the battery cell working window, and ΔT1 is used to represent the first over-limit temperature threshold. The preset temperature threshold can be T max and ΔT1. If ΔCellV ≥ V1, and CellT max ≥T max +ΔT1, continue the preset frame length, determine the extreme risk warning level of the power battery is level 2. The extreme risk warning level of the power battery can be reported.

[0042] Step S2023: If the difference is greater than or equal to the pressure difference threshold, and the maximum value of the temperature value in the monomer temperature sequence is greater than or equal to the preset temperature threshold for a preset time period, the extreme risk warning level of the power battery is determined to be level 2.

[0043] In this step, if ΔCellV ≥ V1, and CellT max ≥T max +ΔT1, lasting for a preset time, determines that the extreme risk warning level of the power battery is level 2. The extreme risk warning level of the power battery can be reported.

[0044] In some optional embodiments, if ΔCellV≥V1+V2, and CellT max ≥T max +ΔT1+ΔT2, continues for a preset frame length, or continues for a preset time, and determines that the extreme risk warning level of the power battery is level 3. Among them, V2 represents the second threshold of the pressure difference, and ΔT2 represents the second over-limit temperature threshold.

[0045] Specifically, through expert review, V1=0.3V, V2=0.1V, ΔT1=5°C, ΔT2=5°C can be defined, the preset frame length can be set to 3 frames, the preset duration can be set to 10 seconds, and T max=55℃. If the cell voltage extreme difference ΔCellV≥0.3V lasts for 3 frames or 10 seconds, the first level extreme difference risk warning level can be reported. max ≥T max +ΔT1+ΔT2=60℃, lasts for 3 frames or 10 seconds, the second level extreme difference risk warning level can be reported. max ≥T max +ΔT 11 +ΔT2=60℃, lasting for 3 frames or 10 seconds continuously, the third level extreme risk warning level can be reported.

[0046] Step S203, based on the safety warning level triggered by the power battery, determine the warning score, and based on the warning score, generate the risk level of the power battery, wherein the safety warning level includes one or a combination of the following warning levels: overvoltage risk warning level, over-discharge risk warning level, and extreme risk warning level. For details, please refer to Figure 1 Step S103 of the illustrated embodiment will not be described in detail here.

[0047] In this way, for voltage consistency anomalies caused by abnormal aging of single cells, by establishing an extreme difference risk warning model, by coupling the temperature signal with the maximum voltage difference, refining the warning level intervals at different levels, and setting the warning trigger conditions at different levels, faults of different severity can be quantified. Through multi-dimensional signal fusion, accurate extreme difference risk warning is achieved, and combined with the judgment conditions of duration or continuous frame length, false alarms can be avoided and the accuracy of warnings can be improved.

[0048] In some optional embodiments, a warning score is determined based on the safety warning level triggered by the power battery, including: determining the highest level among the safety warning levels triggered by the power battery, and determining a basic warning score based on the highest level; determining the number of target levels in the safety warning levels triggered by the power battery, determining an upward coefficient corresponding to the target level, and generating a warning upward score for the target level based on the product of the warning basic score, the upward coefficient corresponding to the target level, and the number of target levels; determining a warning score based on the sum of the warning basic score and the warning upward scores of each level.

[0049] In this embodiment, the safety warning level of the power battery includes a first level overvoltage risk warning level, a second level overvoltage risk warning level, a third level overvoltage risk warning level, a first level overdischarge risk warning level, a second level overdischarge risk warning level, a third level overdischarge risk warning level, and a first level extreme difference risk warning level, a second level extreme difference risk warning level, and a third level extreme difference risk warning level. The scores corresponding to each safety warning level are shown in Table 1.

[0050] Table 1 Correspondence between safety warning levels and scores

[0051]

[0052] In the process of implementing the embodiments of the present invention, the score of the safety warning level can be adjusted according to the actual application scenario. If there are multiple highest-level safety warnings, the higher score corresponding to the safety warning level is determined as the warning basic score. For example, if the power battery triggers the second-level over-discharge risk warning level and the second-level extreme risk warning level, 2.5 points are used as the warning basic score.

[0053] Security warnings include multiple levels. The security warning level can be set to level 1 and level 2, or level 1, level 2 and level 3, or level 1, level 2, level 3 and level 4. The specific number of registrations can be determined based on the actual application scenario. The following takes the example of the security warning level including three levels to explain the determination of the warning score.

[0054] The floating coefficient corresponding to the target level can be determined in the following way: the first floating coefficient a1 corresponds to the first safety warning level, the second floating coefficient a2 corresponds to the second safety warning level, and the third safety warning level corresponds to the third floating coefficient a3. In the case of triggering multiple characteristic types of safety warnings, on the basis of determining the basic warning score, for each additional first safety warning level triggered, the first floating coefficient a1 is increased on the basis of the basic warning score; similarly, on the basis of determining the basic warning score, for each additional second safety warning level triggered, the second floating coefficient a2 is increased on the basis of the basic warning score; similarly, on the basis of determining the basic warning score, for each additional third safety warning level triggered, the third floating coefficient a3 is increased on the basis of the basic warning score.

[0055] Specifically, it can be defined by expert review, a1 = 5%, a2 = 10%, a3 = 15%. If the power battery currently triggers the second level overvoltage risk warning level, the third level overvoltage risk warning level, the first level extreme risk warning level, the second level extreme risk warning level and the third level extreme risk warning level. The highest level is the third level overvoltage risk warning level and the third level extreme risk warning level, and the 3.5 points corresponding to the third level overvoltage risk warning level are used as the warning basic score. The number of first level safety warnings triggered is 1, the number of second level safety warnings triggered is 2, and the number of third level safety warnings triggered is 2. The warning floating score of the first level safety warning is 3.5*0.05*1=0.175; the warning floating score of the second level safety warning is 3.5*0.1*2=0.7; the warning floating score of the third level safety warning is 3.5*0.15*2=1.05. The warning score N=3.5+0.175+0.7+1.05=5.425.

[0056] In this way, for different levels of warning items, the degree of harm caused by the warning trigger is considered, and the score of a single warning is defined by expert review. The greater the degree of harm after the fault is triggered, the higher the warning level and the higher the warning score set, which can accurately quantify the risk status of the battery. By introducing the number of target levels and the floating coefficient, the impact of multiple warning levels can be comprehensively considered, and the limitations of single-level evaluation can be avoided. By setting the floating coefficient for the target level, the warning score can be dynamically adjusted to reflect the superposition effect of multiple risk levels, which can further improve the accuracy of the warning.

[0057] In some optional embodiments, the risk level of the power battery is generated based on the warning score, including: if the warning score is zero, the generated risk level of the power battery is safe; if the warning score is greater than or equal to the first warning threshold, and the warning score is less than the second warning threshold, the generated risk level of the power battery is the first risk level; if the warning score is greater than or equal to the second warning threshold, and the warning score is less than the third warning threshold, the generated risk level of the power battery is the second risk level; if the warning score is greater than or equal to the third warning threshold, the generated risk level of the power battery is the third risk level.

[0058] In this embodiment, the risk level of the power battery can be divided based on the range of the warning score. The corresponding relationship between the warning score and the risk level of the power battery is shown in Table 2. The warning score N is 0, indicating that there is no safety risk of the power battery at present, and the risk level is safe; the warning score N is greater than or equal to the first warning threshold A1, and the warning score N is less than the second warning threshold A2, indicating that the current power battery has a low risk, and the risk level is the first risk level; the warning score is greater than or equal to the second warning threshold A2, and the warning score N is less than the third warning threshold A3, indicating that the current power battery has a medium risk, and the risk level is the second risk level; the warning score N is greater than or equal to the third warning threshold A3, indicating that the current power battery has a high risk, and the risk level is the third risk level.

[0059] The values ​​of the first warning threshold A1, the second warning threshold A2 and the third warning threshold A3 can be determined by expert review. A1 can be set to 1, A2 can be set to 2, and A3 can be set to 3. For the case where the warning score N is 5.425, based on 5.425, the risk level of the power battery is generated as the third risk level, indicating that the current power battery is at high risk.

[0060] Table 2 Correspondence between warning scores and risk levels of power batteries

[0061] Warning score 0 <![CDATA[A1≤N<A2]]> <![CDATA[A2≤N<A3]]> <![CDATA[N≥A3]]> Risk Level Safety First risk level Second risk level Third risk level

[0062] In this way, considering the actual impact of factors such as battery material stability, battery energy density, life stage, SOC status, and ambient temperature on the difficulty of thermal runaway triggering, process acceleration, and disaster level, the trigger condition range of the safety warning threshold system is set. By setting multiple warning thresholds such as the first warning threshold, the second warning threshold, and the third warning threshold, the risk status of the power battery can be clearly divided into multiple levels such as the first risk level, the second risk level, and the third risk level. The division of risk levels is simple and intuitive, which is convenient for users and power battery management systems to quickly understand the safety status of the battery. At the same time, the risk level is generated based on the quantitative results of the warning score, which can accurately reflect the overall risk status of the battery.

[0063] In some optional embodiments, the overvoltage risk warning level and over-discharge risk warning level of the power battery are determined based on the single cell voltage sequence, including: determining the overvoltage threshold based on the single cell operating voltage upper limit, the first over-limit voltage threshold and the second over-limit voltage threshold of the power battery; if the maximum value of the voltage value in the single cell voltage sequence is greater than or equal to the overvoltage threshold for a preset frame length, or if the maximum value of the voltage value in the single cell voltage sequence is greater than or equal to the overvoltage threshold for a preset time length, the overvoltage risk warning level of the power battery is determined to be level two.

[0064] In this embodiment, the upper limit of the single-cell operating voltage of the power battery can be expressed as V max The first over-limit voltage threshold can be represented by ΔV1, and the second over-limit voltage threshold can be represented by ΔV2. The maximum voltage value in the cell voltage sequence can be represented by CellV max The overvoltage threshold can be expressed as V max , ΔV1 and ΔV2 can be determined by summing them up, or by combining the characteristics of a specific type of power battery, or by combining them with a specific application scenario. ΔV1 and ΔV2 can be determined by expert review.

[0065] The following is the V max The overvoltage threshold is determined by summing ΔV1, ΔV2, and the determination of the overvoltage risk warning level of the power battery is described.

[0066] If the maximum voltage value in the cell voltage sequence is CellV max If the voltage is greater than or equal to the first overvoltage threshold and lasts for a preset frame length or a preset time, the overvoltage risk warning level of the power battery is determined to be level 1. The first overvoltage threshold can be determined by measuring the upper limit of the single working voltage V max The sum of ΔV1 and the first over-limit voltage threshold ΔV1 is obtained.

[0067] If the maximum voltage value in the cell voltage sequence is CellV max If the voltage is greater than or equal to the overvoltage threshold and lasts for a preset frame length C or a preset time T, the overvoltage risk warning level of the power battery is determined to be level 2. The overvoltage threshold can be determined by measuring the upper limit of the single working voltage V of the power battery. max , the first over-limit voltage threshold ΔV1 and the second over-limit voltage threshold ΔV2 are summed to obtain.

[0068] If the maximum voltage value in the cell voltage sequence is CellV max Greater than or equal to the overvoltage threshold, and the maximum voltage value CellV in the single cell voltage sequence max Greater than or equal to the upper limit of the battery cell operating window temperature T max , continuously for a preset frame length or a preset time length, and determine that the overvoltage risk warning level of the power battery is level three.

[0069] Specifically, we define V by expert review. max =4.2V, ΔV1=0.1V, ΔV2=0.32V, T max =55°C. C frames can be 3 frames, and T seconds can be 10 seconds. If the maximum voltage value CellV max ≥V max+ΔV1=4.3V, lasts for more than 3 frames or more than 10 seconds, the overvoltage risk warning level of the power battery is determined to be level 1, and the level 1 overvoltage risk warning level is reported. max ≥V max +ΔV1+ΔV2=4.62V, lasts for more than 3 frames or more than 10 seconds, the overvoltage risk warning level of the power battery is determined to be level 2, and the level 2 overvoltage risk warning level is reported. max ≥V max +ΔV1+ΔV2=4.62V, and CellV max ≥55℃, lasts for more than 3 frames or more than 10 seconds, determines that the overvoltage risk warning level of the power battery is level 3, and reports the level 3 overvoltage risk warning level.

[0070] In this way, for the overcharge risk that may exist in the battery system during parking charging or driving kinetic energy recovery, an overvoltage risk warning model is established, and the temperature signal is coupled to refine the warning level intervals of different levels, which can accurately determine the overvoltage risk status of the battery. At the same time, in view of the impact of the accuracy of the battery system sensor and the data collection interval on the false alarm rate of the threshold model fault, it is triggered from the two levels of timing requirements and fault signal degree requirements, and containment and limitation conditions are established to filter abnormal data scenarios, improve the accuracy of algorithm reporting, and reduce the false alarm rate.

[0071] In some optional embodiments, based on the single cell voltage sequence, determining the overvoltage risk warning level and over-discharge risk warning level of the power battery also includes: determining the over-discharge threshold based on the single cell operating voltage lower limit, the third over-limit voltage threshold and the fourth over-limit voltage threshold of the power battery; if the minimum value of the voltage value in the single cell voltage sequence is less than or equal to the over-discharge threshold for a preset frame length, or if the minimum value of the voltage value in the single cell voltage sequence is less than or equal to the over-discharge threshold for a preset time length, determining that the over-discharge risk warning level of the power battery is level two.

[0072] In this embodiment, the lower limit of the single-cell operating voltage of the power battery can be expressed as V min The third over-limit voltage threshold can be represented by ΔV3, and the fourth over-limit voltage threshold can be represented by ΔV4. The maximum voltage value in the cell voltage sequence can be represented by CellV min The over-discharge threshold can be expressed as V min Subtract ΔV3 and ΔV4 to get, or it can be determined in combination with the characteristics of a specific model of power battery, or it can be determined in combination with a specific application scenario. ΔV3 and ΔV4 can be determined by expert review.

[0073] The following uses V minThe over-discharge threshold is determined by subtracting ΔV3 and ΔV4, and the determination of the over-discharge risk warning level of the power battery is described.

[0074] If the minimum voltage value in the cell voltage sequence is CellV min If the voltage is less than or equal to the first over-discharge threshold for a preset frame length or a preset time, the over-discharge risk warning level of the power battery is determined to be level 1. The first over-discharge threshold can be determined by measuring the lower limit of the single-cell working voltage V max Subtract the third over-limit voltage threshold ΔV3 to obtain.

[0075] If the minimum voltage value in the cell voltage sequence is CellV min If the voltage is less than or equal to the over-discharge threshold for a preset frame length or a preset time, the over-discharge risk warning level of the power battery is determined to be level 2. The over-discharge threshold can be obtained by subtracting ΔV3 and ΔV4 from the lower limit of the single-cell operating voltage of the power battery.

[0076] If the minimum voltage value in the cell voltage sequence is CellV min Less than or equal to the over-discharge threshold, and the maximum voltage value CellV in the cell voltage sequence max Greater than or equal to the upper limit of the battery cell operating window temperature T max , continuously for a preset frame length or a preset time length, and determine that the over-discharge risk warning level of the power battery is level three.

[0077] Specifically, we define V by expert review. min =2V, ΔV3=0.3V, ΔV4=0.7V, T max =55°C. C frames can be 3 frames, and T seconds can be 10 seconds. If the minimum voltage value CellV min ≤V min -ΔV3=1.7V, lasts for more than 3 frames or more than 10 seconds, the over-discharge risk warning level of the power battery is determined to be level 1, and the level 1 over-discharge risk warning level is reported. min ≤V min -ΔV3-ΔV4=1V, lasts for more than 3 frames or more than 10 seconds, the over-discharge risk warning level of the power battery is determined to be level 2, and the level 2 over-discharge risk warning level is reported. min ≤V min -ΔV3-ΔV4=1V, and CellV max ≥55℃, lasts for more than 3 frames or more than 10 seconds, the over-discharge risk warning level of the power battery is determined to be level 3, and the level 3 over-discharge risk warning level is reported.

[0078] In this way, for over-discharge problems caused by self-discharge or internal short circuit in driving, charging or parking scenarios, an over-discharge risk warning model is established. At the same time, the temperature signal is coupled to refine the over-discharge warning level intervals at different levels. A graded alarm system is established for different safety risk levels. According to the degree of hazard, signal characteristics, and early alarm requirements of different thermal runaway stages, corresponding threshold parameters are formulated to ensure timely response and effective measures. For the first and second level heavy warnings, the fault is reported tens of minutes or even hours before the thermal runaway occurs, which is suitable for the early and middle stages of evolutionary thermal runaway scenarios. For the third level heavy alarm, the fault must be reported ≥5 minutes before the loss of control. It is suitable for the late stage of evolutionary thermal runaway scenarios and can accurately judge the over-discharge risk status of the battery.

[0079] In this embodiment, a device for power battery safety warning based on the fusion of voltage and temperature signals is also provided, which is used to implement the above-mentioned embodiments and preferred implementation modes, and will not be repeated hereafter. As used below, the term "module" can implement a combination of software and / or hardware of a predetermined function. Although the devices described in the following embodiments are preferably implemented in software, the implementation of hardware, or a combination of software and hardware, is also possible and conceivable.

[0080] This embodiment provides a power battery safety warning device based on the fusion of voltage and temperature signals. Figure 3 FIG. 1 is a schematic diagram showing a structure of a power battery safety warning device based on voltage and temperature signal fusion according to an embodiment of the present invention. Figure 3 As shown, including:

[0081] The first acquisition module 301 is used to acquire a cell voltage sequence of the power battery, and determine an overvoltage risk warning level and an over-discharge risk warning level of the power battery based on the cell voltage sequence.

[0082] The second acquisition module 302 is used to acquire the cell temperature sequence of the power battery, and determine the extreme risk warning level of the power battery based on the cell voltage sequence and the cell temperature sequence.

[0083] The warning module 303 is used to determine the warning score based on the safety warning level triggered by the power battery, and generate the risk level of the power battery based on the warning score, wherein the safety warning level includes one or a combination of the following warning levels: overvoltage risk warning level, over-discharge risk warning level and extreme risk warning level.

[0084] The device for power battery safety warning based on voltage and temperature signal fusion provided in the embodiment of the present invention establishes the combined characteristics of power battery thermal runaway development characteristic signals, sets characteristic parameter judgment conditions of single cell voltage and single cell temperature signals; defines the severity according to fault classification, and establishes a multi-level battery safety risk warning strategy; quantifies the safety risk of the power battery system based on the thermal runaway multi-model perception results, which is conducive to timely and effective identification of power battery safety risks, ensuring the safe operation of vehicles, and promoting the rapid development of new energy vehicles.

[0085] In some optional implementations, the second acquisition module 302 includes:

[0086] The first unit of the second acquisition module is used to determine the difference between the maximum value and the minimum value of the power battery cell voltage, the maximum value of the voltage in the cell voltage sequence is the maximum value of the cell voltage, and the minimum value of the voltage in the cell voltage sequence is the minimum value of the cell voltage.

[0087] The second unit of the second acquisition module is used to determine that the extreme risk warning level of the power battery is level 2 if the difference is greater than or equal to the pressure difference threshold, and the maximum value of the temperature value in the monomer temperature sequence is greater than or equal to the preset temperature threshold for a preset frame length.

[0088] The third unit of the second acquisition module is used to determine that the extreme risk warning level of the power battery is level 2 if the difference is greater than or equal to the pressure difference threshold, and the maximum value of the temperature value in the monomer temperature sequence is greater than or equal to the preset temperature threshold for a preset time period.

[0089] In some optional implementations, the early warning module 303 includes:

[0090] The first unit of the warning module is used to determine the highest level of the safety warning levels triggered by the power battery, and determine the warning basic score based on the highest level.

[0091] The second unit of the warning module is used to determine the number of target levels in the safety warning level triggered by the power battery, determine the floating coefficient corresponding to the target level, and generate the warning floating score of the target level based on the product of the warning basic score, the floating coefficient corresponding to the target level and the number of target levels.

[0092] The third unit of the early warning module is used to determine the early warning score based on the sum of the early warning basic score and the early warning floating scores of each level.

[0093] In some optional implementations, the early warning module 303 further includes:

[0094] The fourth unit of the early warning module is used to generate a safe risk level for the power battery if the early warning score is zero; if the early warning score is greater than or equal to the first early warning threshold, and the early warning score is less than the second early warning threshold, the risk level of the power battery generated is the first risk level; if the early warning score is greater than or equal to the second early warning threshold, and the early warning score is less than the third early warning threshold, the risk level of the power battery generated is the second risk level; if the early warning score is greater than or equal to the third early warning threshold, the risk level of the power battery generated is the third risk level.

[0095] In some optional implementations, the first acquisition module 301 includes:

[0096] The first unit of the first acquisition module is used to determine the overvoltage threshold based on the single cell operating voltage upper limit, the first over-limit voltage threshold and the second over-limit voltage threshold of the power battery; if the maximum value of the voltage value in the single cell voltage sequence is greater than or equal to the overvoltage threshold for a preset frame length, or if the maximum value of the voltage value in the single cell voltage sequence is greater than or equal to the overvoltage threshold for a preset time length, it is determined that the overvoltage risk warning level of the power battery is level two.

[0097] In some optional implementations, the first acquisition module 301 further includes:

[0098] The second unit of the first acquisition module is used to determine the over-discharge threshold value based on the lower limit of the single cell operating voltage, the third over-limit voltage threshold value and the fourth over-limit voltage threshold value of the power battery; if the minimum value of the voltage value in the single cell voltage sequence is less than or equal to the over-discharge threshold value for a preset frame length, or if the minimum value of the voltage value in the single cell voltage sequence is less than or equal to the over-discharge threshold value for a preset time length, it is determined that the over-discharge risk warning level of the power battery is level two.

[0099] The further functional description of each of the above modules and units is the same as that of the above corresponding embodiments and will not be repeated here.

[0100] The power battery safety warning device based on the fusion of voltage and temperature signals in this embodiment is presented in the form of a functional unit, where the unit refers to an application specific integrated circuit (ASIC) circuit, a processor and memory that executes one or more software or fixed programs, and / or other devices that can provide the above functions.

[0101] The embodiment of the present invention also provides a computer device having the above Figure 3 The device shown is a power battery safety warning device based on the fusion of voltage and temperature signals.

[0102] See also Figure 4 , Figure 4is a schematic diagram of the structure of a computer device provided by an optional embodiment of the present invention, such as Figure 4 As shown, the computer device includes: one or more processors 10, a memory 20, and interfaces for connecting various components, including high-speed interfaces and low-speed interfaces. Various components are connected to each other using different buses for communication, and can be installed on a common mainboard or installed in other ways as needed. The processor can process instructions executed in the computer device, including instructions stored in or on the memory to display graphical information of a graphical user interface on an external input / output device (such as a display device coupled to an interface). In some optional embodiments, if necessary, multiple processors and / or multiple buses can be used together with multiple memories and multiple memories. Similarly, multiple computer devices can be connected, and each device provides some necessary operations (for example, as a server array, a group of blade servers, or a multi-processor system). Figure 4 A processor 10 is taken as an example.

[0103] The processor 10 may be a central processing unit, a network processor or a combination thereof. The processor 10 may further include a hardware chip. The hardware chip may be a dedicated integrated circuit, a programmable logic device or a combination thereof. The programmable logic device may be a complex programmable logic device, a field programmable gate array, a general purpose array logic or any combination thereof.

[0104] The aforementioned memory 20 stores instructions executable by at least one processor 10, so that the aforementioned at least one processor 10 executes the method shown in the above embodiment.

[0105] The memory 20 may include a program storage area and a data storage area, wherein the program storage area may store an operating system, an application required for at least one function; the data storage area may store data created according to the use of the computer device, etc. In addition, the memory 20 may include a high-speed random access memory, and may also include a non-transient memory, such as at least one disk storage device, a flash memory device, or other non-transient solid-state storage device. In some optional embodiments, the memory 20 may optionally include a memory remotely arranged relative to the processor 10, and these remote memories may be connected to the computer device via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0106] The memory 20 may include a volatile memory, such as a random access memory; the memory may also include a non-volatile memory, such as a flash memory, a hard disk or a solid state drive; the memory 20 may also include a combination of the above types of memory.

[0107] The computer device also includes an input device 30 and an output device 40. The processor 10, the memory 20, the input device 30 and the output device 40 may be connected via a bus or other means. Figure 4 The example of connecting through bus is taken in the following.

[0108] The input device 30 can receive input digital or character information, and generate key signal input related to the user settings and function control of the computer device, such as a touch screen, a keypad, a mouse, a track pad, a touch pad, an indicator rod, one or more mouse buttons, a trackball, a joystick, etc. The output device 40 may include a display device, an auxiliary lighting device (such as a light emitting diode) and a tactile feedback device (such as a vibration motor), etc. The above-mentioned display device includes but is not limited to a liquid crystal display, a light emitting diode, a display and a plasma display. In some optional embodiments, the display device can be a touch screen.

[0109] The embodiment of the present invention also provides a computer-readable storage medium. The method according to the embodiment of the present invention can be implemented in hardware, firmware, or can be implemented as a computer code that can be recorded in a storage medium, or can be implemented as a computer code that is originally stored in a remote storage medium or a non-temporary machine-readable storage medium and will be stored in a local storage medium through a network download, so that the method described herein can be stored in such software processing on a storage medium using a general-purpose computer, a dedicated processor, or programmable or dedicated hardware. Among them, the storage medium can be a magnetic disk, an optical disk, a read-only storage memory, a random access memory, a flash memory, a hard disk or a solid-state hard disk, etc.; further, the storage medium can also include a combination of the above types of memories. It can be understood that a computer, a processor, a microprocessor controller, or programmable hardware includes a storage component that can store or receive software or computer code. When the software or computer code is accessed and executed by a computer, a processor, or hardware, the method shown in the above embodiment is implemented.

[0110] A part of the present invention may be applied as a computer program product, such as a computer program instruction, which, when executed by a computer, can call or provide the method and / or technical solution according to the present invention through the operation of the computer. Those skilled in the art should understand that the existence of the computer program instruction in a computer-readable medium includes, but is not limited to, a source file, an executable file, an installation package file, etc., and accordingly, the way in which the computer program instruction is executed by the computer includes, but is not limited to: the computer directly executes the instruction, or the computer compiles the instruction and then executes the corresponding compiled program, or the computer reads and executes the instruction, or the computer reads and installs the instruction and then executes the corresponding installed program. Here, the computer-readable medium may be any available computer-readable storage medium or communication medium accessible to the computer.

[0111] Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A method for power battery safety early warning based on voltage and temperature signal fusion, characterized in that: The method comprises: Acquire a cell voltage sequence of a power battery, and determine an overvoltage risk warning level and an over-discharge risk warning level of the power battery based on the cell voltage sequence; Acquire a cell temperature sequence of the power battery, and determine a critical risk warning level of the power battery based on the cell voltage sequence and the cell temperature sequence; Based on the safety warning level triggered by the power battery, a warning score is determined, and based on the warning score, a risk level of the power battery is generated, wherein the safety warning level includes one or a combination of the following warning levels: overvoltage risk warning level, over-discharge risk warning level and extreme risk warning level.

2. The method according to claim 1, characterized in that The acquiring the cell temperature sequence of the power battery and determining the extreme risk warning level of the power battery based on the cell voltage sequence and the cell temperature sequence includes: Determine the difference between the maximum value and the minimum value of the power battery cell voltage, the maximum value of the voltage in the cell voltage sequence is the maximum value of the cell voltage, and the minimum value of the voltage in the cell voltage sequence is the minimum value of the cell voltage; If the difference is greater than or equal to the pressure difference threshold, and the maximum value of the temperature values ​​in the monomer temperature sequence is greater than or equal to the preset temperature threshold for a preset frame length, it is determined that the extreme risk warning level of the power battery is level 2; or, If the difference is greater than or equal to the pressure difference threshold, and the maximum value of the temperature values ​​in the monomer temperature sequence is greater than or equal to the preset temperature threshold for a preset time period, it is determined that the extreme risk warning level of the power battery is level two.

3. The method according to claim 1, characterized in that: The determining of the warning score based on the safety warning level triggered by the power battery includes: Determining a highest level among the safety warning levels triggered by the power battery, and determining a warning basic score based on the highest level; Determine the number of target levels in the safety warning level triggered by the power battery, determine the floating coefficient corresponding to the target level, and generate the warning floating score of the target level based on the product of the warning basic score, the floating coefficient corresponding to the target level and the number of target levels; The warning score is determined based on the sum of the warning basic score and the warning floating scores of each level.

4. The method according to claim 1, characterized in that: The generating the risk level of the power battery based on the warning score includes: If the warning score is zero, the generated risk level of the power battery is safe; If the warning score is greater than or equal to the first warning threshold, and the warning score is less than the second warning threshold, the generated risk level of the power battery is the first risk level; If the warning score is greater than or equal to the second warning threshold, and the warning score is less than the third warning threshold, the generated risk level of the power battery is the second risk level; If the warning score is greater than or equal to the third warning threshold, the generated risk level of the power battery is the third risk level.

5. The method according to claim 1, characterized in that The determining, based on the single cell voltage sequence, the overvoltage risk warning level and the over-discharge risk warning level of the power battery includes: Determining an overvoltage threshold based on the upper limit of the single-cell operating voltage of the power battery, the first over-limit voltage threshold, and the second over-limit voltage threshold; If the maximum value of the voltage values ​​in the single cell voltage sequence is greater than or equal to the overvoltage threshold for a preset frame length, or if the maximum value of the voltage values ​​in the single cell voltage sequence is greater than or equal to the overvoltage threshold for a preset time length, the overvoltage risk warning level of the power battery is determined to be level two.

6. The method according to claim 5, characterized in that The determining of the overvoltage risk warning level and the over-discharge risk warning level of the power battery based on the single cell voltage sequence further includes: Determining an over-discharge threshold based on a lower limit of a single cell operating voltage of the power battery, a third over-limit voltage threshold, and a fourth over-limit voltage threshold; If the minimum voltage value in the single cell voltage sequence is less than or equal to the over-discharge threshold value for a preset frame length, or if the minimum voltage value in the single cell voltage sequence is less than or equal to the over-discharge threshold value for a preset time length, it is determined that the over-discharge risk warning level of the power battery is level two.

7. A power battery safety warning device based on voltage and temperature signal fusion, characterized in that: The device comprises: A first acquisition module is used to acquire a single cell voltage sequence of a power battery, and determine an overvoltage risk warning level and an over-discharge risk warning level of the power battery based on the single cell voltage sequence; A second acquisition module is used to acquire a cell temperature sequence of the power battery, and determine a very poor risk warning level of the power battery based on the cell voltage sequence and the cell temperature sequence; The early warning module is used to determine the early warning score based on the safety early warning level triggered by the power battery, and generate the risk level of the power battery based on the early warning score, wherein the safety early warning level includes one or a combination of the following early warning levels: overvoltage risk early warning level, over-discharge risk early warning level and extreme risk early warning level.

8. A computer device, characterized in that: include: A memory and a processor, wherein the memory and the processor are communicatively connected to each other, the memory stores computer instructions, and the processor executes the method for power battery safety warning based on voltage and temperature signal fusion as described in any one of claims 1 to 6 by executing the computer instructions.

9. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer instructions, and the computer instructions are used to enable a computer to execute the method for power battery safety warning based on voltage and temperature signal fusion according to any one of claims 1 to 6.

10. A computer program product, characterized in that The method comprises computer instructions for causing a computer to execute the method for power battery safety warning based on voltage and temperature signal fusion according to any one of claims 1 to 6.

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