Battery Over-discharge Protection Method, Device and Vehicle

Abstract

The present invention provides a battery over-discharge protection method, device and vehicle. The method includes: obtaining the total power consumption of all electrical devices powered by the battery in the vehicle and the discharge power of the battery; determining the actual discharge power of the battery that can represent the total actual power consumption of all electrical devices according to the total power consumption and the discharge power; comparing the actual discharge power with the maximum discharge power of the battery, and judging whether to adjust the available power of the target electrical device according to the comparison result to avoid over-discharging of the battery. The present invention can avoid the situation that due to the delay of the discharge power signal of the battery, the results obtained after comparing the discharge power with the maximum discharge power may all be incorrect, which may lead to the discharge power output by the battery based on the available power of the target electrical device being higher than the maximum discharge power, resulting in over-discharge of the battery and abnormal over-discharge protection, triggering the battery over-discharge protection, leading to power-off under fault, and even causing irreversible damage to the battery.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicle control, and particularly to a battery over-discharge protection method, device and vehicle. Background Art

[0002] Currently, when the engine is at low idle speed or stopped, or when the power supply capacity of the generator is insufficient, the battery equipped on the vehicle is usually used to supply power to the electrical equipment on the vehicle, such as motors, high-voltage accessories, etc.

[0003] When the discharge power of the battery exceeds its discharge capacity, it will cause irreversible damage to the battery. Therefore, a maximum discharge power is usually set to protect the battery from over-discharge. However, the inventor found in the process of implementing the present invention that due to the signal interaction delay between the vehicle controllers in extremely cold or hot environments, the information of each component received by the vehicle controller is delayed. For example, the current battery discharge power has changed due to the time delay. Therefore, when adjusting the available power of the motor in the vehicle based on the battery discharge power, it may cause the discharge power output by the battery based on the available power of the motor to be too high, resulting in abnormal battery over-discharge protection. Especially for multi-motor vehicle models with more energy-consuming components, the possibility of abnormal battery over-discharge protection is higher. Summary of the Invention

[0004] Embodiments of the present invention provide a battery over-discharge protection method, device and vehicle to solve the problem of abnormal battery over-discharge protection caused by signal interaction delay in extremely cold or hot environments.

[0005] In a first aspect, embodiments of the present invention provide a battery over-discharge protection method, including:

[0006] Obtain the total power consumption of all electrical equipment powered by the battery in the vehicle and the discharge power of the battery;

[0007] Determine the actual discharge power of the battery according to the total power consumption and the discharge power; the actual discharge power represents the total actual power consumption of all electrical equipment;

[0008] Compare the actual discharge power with the maximum discharge power of the battery, and determine whether to adjust the available power of the target electrical equipment according to the comparison result to avoid over-discharge of the battery, where the target electrical equipment is the electrical equipment whose power consumption can be adjusted among all electrical equipment.

[0009] In a possible implementation manner, the determining the actual discharge power of the battery according to the total power consumption and the discharge power includes:

[0010] Determine the maximum value of the total power consumption and the discharge power as the actual discharge power of the battery.

[0011] In a possible implementation, the target electrical device includes all drive motors in a vehicle;

[0012] Comparing the actual discharge power with the maximum discharge power of the battery and determining whether to adjust the available power of the target electrical device according to the comparison result includes:

[0013] Obtain the available power of all drive motors based on the maximum discharge power;

[0014] Calculate the first power difference between the maximum discharge power and the actual discharge power;

[0015] Compare the first power difference with the proportional-integral regulation activation threshold;

[0016] If the first power difference is less than the proportional-integral regulation activation threshold, perform proportional-integral regulation on the available power according to the first power difference, and determine the actual available power of all drive motors according to the result of the proportional-integral regulation.

[0017] In a possible implementation, after comparing the first power difference with the proportional-integral regulation activation threshold, it further includes: if the first power difference is greater than or equal to the proportional-integral regulation activation threshold, determine the available power as the actual available power of all drive motors.

[0018] In a possible implementation, the obtaining the available power of all drive motors based on the maximum discharge power includes:

[0019] Obtain the highest temperature and the lowest temperature of the battery, the actual state of charge of the battery, and the actual power consumption of high-voltage accessories among all electrical devices;

[0020] Determine the temperature correction coefficient and the state-of-charge correction coefficient according to the highest temperature, the lowest temperature, the actual state of charge, and a preset correction coefficient table;

[0021] Correct the maximum discharge power according to the temperature correction coefficient and the state-of-charge correction coefficient to determine the maximum dynamic discharge power of the battery;

[0022] Calculate the difference between the maximum dynamic discharge power and the actual power consumption to obtain the available power of all drive motors.

[0023] In a possible implementation, the battery over-discharge protection method further includes: obtaining the reserved power of the heating device;

[0024] The calculating the difference between the maximum dynamic discharge power and the actual power consumption to obtain the available power of all drive motors includes:

[0025] According to P es =P m ' ax -P hv -P ptc , obtaining the available power of all driving motors;

[0026] Among them, P es Denotes the available power, P m ' ax Represents the maximum dynamic discharge power, P hv Indicates the actual power consumption, P ptc Indicates the reserved power of the heating device.

[0027] In a possible implementation, the battery over-discharge protection method further includes: obtaining a preset power adjustment amount;

[0028] The calculating the difference between the maximum dynamic discharge power and the actual power consumption to obtain the available power of all drive motors includes:

[0029] According to P es =P m ' ax -P hv -P ptc - P0, obtain the available power of all drive motors;

[0030] Wherein, P0 represents the preset power adjustment amount.

[0031] In one possible implementation, all electrical devices in the vehicle powered by the battery include all drive motors and high-voltage accessories in the vehicle;

[0032] The obtaining of the total power consumption of all battery-powered electrical devices in the vehicle includes:

[0033] Obtaining the actual electrical power, actual mechanical power, and actual motor efficiency corresponding to each drive motor, as well as the actual power consumption of the high-voltage accessories;

[0034] Calculate the efficiency-converted electric power of each drive motor based on the actual mechanical power of each drive motor and the corresponding actual motor efficiency;

[0035] Calculating the sum of the electric power converted from the efficiency of each drive motor to obtain the first total electric power of all drive motors;

[0036] Calculate the sum of the actual electric powers of each drive motor to obtain the second total power consumption of all drive motors;

[0037] Determine the maximum value between the first total power consumption and the second total power consumption as the current total power consumption of all drive motors;

[0038] Calculate the sum of the current total power consumption and the actual power consumption to obtain the total power consumption of all electrical devices powered by the battery in the vehicle.

[0039] In a second aspect, an embodiment of the present invention provides a battery over-discharge protection device, including:

[0040] An acquisition module for acquiring the total power consumption of all electrical devices powered by the battery in the vehicle and the discharge power of the battery;

[0041] A first processing module for determining the actual discharge power of the battery according to the total power consumption and the discharge power; the actual discharge power represents the actual total power consumption of all electrical devices;

[0042] A second processing module for comparing the actual discharge power with the maximum discharge power of the battery, and judging whether to adjust the available power of the target electrical device according to the comparison result to avoid over-discharging of the battery, where the target electrical device is an electrical device whose power consumption can be adjusted among all electrical devices.

[0043] In a third aspect, an embodiment of the present invention provides a vehicle, including a controller, where the controller includes a memory, a processor, and a computer program stored in the memory and executable on the processor, and when the processor executes the computer program, it implements the steps of the method in the first aspect or any possible implementation manner of the first aspect as described above.

[0044] In a fourth aspect, an embodiment of the present invention provides a computer-readable storage medium storing a computer program, and when the computer program is executed by a processor, it implements the steps of the method in the first aspect or any possible implementation manner of the first aspect as described above.

[0045] An embodiment of the present invention provides a battery over-discharge protection method, device, and vehicle. The method obtains two signals, namely, the total power consumption of all electrical devices powered by the battery in the vehicle and the discharge power of the battery. According to these two signals of the total power consumption and the discharge power, the actual discharge power of the battery that can represent the actual total power consumption of all electrical devices is determined, that is, the actual discharge power of the battery with the smallest signal delay. The actual discharge power of the battery is compared with the maximum discharge power of the battery, and whether to adjust the available power of the target electrical device is judged according to the comparison result. This is to avoid directly comparing the discharge power of the battery with the maximum discharge power of the battery. When subsequent judgments and adjustments are made according to the comparison result, if the signal of the discharge power of the battery is delayed, both the obtained comparison result and the judgment result may be incorrect, which may further cause the discharge power output by the battery based on the available power of the target electrical device to be higher than the maximum discharge power of the battery, resulting in over-discharge of the battery, and further leading to abnormal battery over-discharge protection, triggering battery over-discharge protection, resulting in power-off under fault, and even causing irreversible damage to the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for use in the embodiments or the description of the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0047] Figure 1 is a flowchart of the implementation of the battery over-discharge protection method provided by the embodiment of the present invention;

[0048] Figure 2 is a flowchart of the implementation of the battery over-discharge protection method provided by another embodiment of the present invention;

[0049] Figure 3 is a flowchart of the implementation of the battery over-discharge protection method provided by another embodiment of the present invention;

[0050] Figure 4 is a schematic structural diagram of the battery over-discharge protection device provided by the embodiment of the present invention;

[0051] Figure 5 is a schematic diagram of the controller provided by the embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0052] In the following description, specific details such as specific system architectures and technologies are presented for the purpose of illustration rather than limitation, so as to thoroughly understand the embodiments of the present invention. However, those skilled in the art should understand that the present invention can also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to avoid unnecessary details from interfering with the description of the present invention.

[0053] To make the objectives, technical solutions, and advantages of the present invention clearer, the following will be described through specific embodiments in conjunction with the accompanying drawings.

[0054] Refer to Figure 1 , which shows the implementation flowchart of the battery over-discharge protection method provided by the embodiments of the present invention, and is described in detail as follows:

[0055] Step 101, obtain the total power consumption of all electrical devices powered by the battery in the vehicle and the discharge power of the battery.

[0056] Exemplarily, in the vehicle, all electrical devices powered by the battery may include all drive motors in the vehicle, as well as high-voltage accessories on the vehicle such as a DC conversion device, an air conditioner, etc. Obtaining the total power consumption of all electrical devices powered by the battery in the vehicle and the discharge power of the battery can be achieved by the vehicle control unit (VCU) collecting relevant information of the battery, drive motors, and high-voltage accessories, and obtaining the total power consumption of all electrical devices powered by the battery in the vehicle and the discharge power of the battery based on the collected relevant information of the battery, drive motors, and high-voltage accessories. Among them, the VCU can collect the relevant information of the battery, drive motors, and high-voltage accessories by receiving the information sent by the corresponding controllers of the battery, drive motors, and high-voltage accessories. After collecting the relevant information of the battery, drive motors, and high-voltage accessories, low-pass filtering can be added to the collected signals to prevent signal jumps from causing drive motor power jumps, and thus causing the vehicle's overall torque to drop.

[0057] In extremely cold or hot environments, signal interaction between controllers on the vehicle usually experiences delays, resulting in the possibility of over-discharging the vehicle's battery if the directly collected discharge power of the battery is used. By calculating and comparing signals from multiple different controllers that can reflect the current overall vehicle power usage, the battery discharge power that best represents the extreme discharge stage (i.e., the early stage when the battery is about to be over-discharged) can be obtained to reduce the influence of environmental factors. Theoretically, at the same moment, the total power consumption of all electrical devices powered by the battery in the vehicle should be the same as the discharge power of the battery. Therefore, these two signals, namely the total power consumption of all electrical devices powered by the battery in the vehicle and the discharge power of the battery, can be obtained simultaneously, and the two signals can be mutually corrected to determine the actual discharge power of the battery with the minimum signal delay.

[0058] Optionally, obtaining the total power consumption of all electrical devices powered by the battery in the vehicle may include: obtaining the actual electrical power, actual mechanical power, and actual motor efficiency corresponding to each drive motor, as well as the actual power consumption of high-voltage accessories; calculating the efficiency-converted electrical power of each drive motor according to the actual mechanical power of each drive motor and the corresponding actual motor efficiency; calculating the sum of the efficiency-converted electrical powers of each drive motor to obtain the first total power consumption of all drive motors; calculating the sum of the actual electrical powers of each drive motor to obtain the second total power consumption of all drive motors; determining the maximum value between the first total power consumption and the second total power consumption as the current total power consumption of all drive motors; calculating the sum of the current total power consumption of all drive motors and the actual power consumption of high-voltage accessories to obtain the total power consumption of all electrical devices powered by the battery in the vehicle.

[0059] In this embodiment, the vehicle may include only a single drive motor, or may include 2, 3, or 4 drive motors. This embodiment does not limit the number of drive motors in the vehicle.

[0060] When obtaining the total power consumption of all electrical devices powered by the battery in the vehicle, it can be carried out in two parts. One part is the total power consumption of all drive motors in the vehicle, and the other part is the total power consumption of high-voltage accessories. Calculate the sum of the total power consumption of all drive motors and the total power consumption of high-voltage accessories, that is, obtain the total power consumption of all electrical devices powered by the battery in the vehicle.

[0061] Among them, the total power consumption of high-voltage accessories (i.e., the actual power consumption of high-voltage accessories) can be obtained by calculating the sum of the actual power consumption of the DC conversion device and the actual power consumption of the air conditioner.

[0062] Exemplarily, the actual power consumption of the DC conversion device can be 2.5 KW, and the actual power consumption of the air conditioner can be 4 KW, then the actual power consumption of high-voltage accessories is 6.5 KW.

[0063] Among them, when obtaining the total power consumption of all drive motors in the vehicle, two signals can also be collected, and through mutual correction of the two signals, the maximum value of the two signals is determined as the current total power consumption of all drive motors, so that the obtained total power consumption of all drive motors (i.e., the current total power consumption) is more reliable, and further the determined actual discharge power of the battery is more reliable.

[0064] Exemplarily, one path of signal can collect the voltage and current of each drive motor, and then obtain the actual electric power of each drive motor, calculate the sum of the actual electric powers of each drive motor, and use it as the total power consumption of all drive motors, that is, the second total power consumption of all drive motors. Another path of signal can collect the actual motor speed and torque of each drive motor, calculate the actual mechanical power of each drive motor according to the actual motor speed and torque of each drive motor, respectively obtain the actual motor efficiency of each drive motor, and calculate the efficiency conversion electric power of each drive motor according to the actual mechanical power of each drive motor and the corresponding actual motor efficiency, calculate the sum of the efficiency conversion electric powers of each drive motor, and use it as the total power consumption of all drive motors, that is, the first total power consumption of all drive motors. Then, determine the maximum value between the first total power consumption and the second total power consumption as the current total power consumption of all drive motors.

[0065] Exemplarily, assume that the actual motor speed of drive motor 1 is 5000 rpm and the torque is 124.15 N·m. Then, based on the torque formula T = 9550P / n, the actual mechanical power of drive motor 1 can be calculated as 65 KW, where T represents torque, P represents power, and n represents speed.

[0066] Similarly, for multiple drive motors, the actual mechanical power of the drive motors can be calculated according to the above method.

[0067] Among them, when obtaining the actual motor efficiency of each drive motor, bench tests can be carried out in advance under different voltage platforms (such as 220V, 250V, 300V, 380V, and 420V), measure and calculate the actual efficiency of each drive motor at different speeds and torques under different voltage platforms, and obtain multiple groups of efficiency maps of each drive motor under different voltage platforms, that is, the actual efficiency corresponding to different speeds and torques under each voltage platform. For one of the drive motors, the VCU can select adjacent voltage platforms U0 and U1 (for example, if U act = 230V, then U0 = 220V, U1 = 250V) according to the actual voltage (U act ) of the drive motor, search in the efficiency maps of the adjacent voltage platforms U0 and U1 according to the actual speed and torque of the drive motor, obtain the efficiencies E0 and E1, and then calculate the actual motor efficiency E act of the drive motor at the actual voltage through the interpolation method: Then, obtain the actual motor efficiency of each drive motor according to this method.

[0068] Exemplarily, assume that the actual voltage U actIf = 340V, then the efficiency E0 = 70% is obtained by looking up in the efficiency map of the adjacent voltage platform U0 = 300V, and the efficiency E1 = 80% is obtained by looking up in the efficiency map of the adjacent voltage platform U1 = 380V. The actual motor efficiency of the drive motor under the actual voltage is calculated by the interpolation method.

[0069] In addition, if the signal delay of the sensors corresponding to each drive motor is not considered, the sum of the actual electric powers of each drive motor can also be directly used as the total power consumption of all drive motors.

[0070] Step 102, determine the actual discharge power of the battery according to the total power consumption and the discharge power.

[0071] Among them, the actual discharge power of the battery represents the total actual power consumption of all electrical equipment.

[0072] That is to say, the total power consumption of all electrical equipment obtained in step 101 may be delayed, or the discharge power of the battery obtained in step 101 may be delayed. In this embodiment, according to the total power consumption and the discharge power, the one with the smallest signal delay in the total power consumption and the discharge power can be determined as the actual discharge power of the battery, that is, the total actual power consumption of all electrical equipment.

[0073] Optionally, the maximum value of the total power consumption and the discharge power can be determined as the actual discharge power of the battery.

[0074] Exemplarily, for the case where there are 2 drive motors in the vehicle, the actual discharge power of the battery can be determined by PbattAct = max{max[PwrMlecMot1 / E act1 +PwrMlecMot2 / E act2 , PwrMot1 + PwrMot2] + PwrHVBoard, PwrBatt}.

[0075] Among them, PwrMlecMot1 represents the actual mechanical power of drive motor 1, E act1 represents the actual motor efficiency of drive motor 1, PwrMot1 represents the actual electric power of drive motor 1, PwrMlecMot2 represents the actual mechanical power of drive motor 2, E act2 represents the actual motor efficiency of drive motor 2, PwrMot2 represents the actual electric power of drive motor 2, PwrHVBoard represents the actual power consumption of the high-voltage accessory, and PwrBatt represents the actual discharge power of the battery.

[0076] In this embodiment, when determining the actual discharge power of the battery based on the total power consumption and the discharge power, the maximum value of the total power consumption and the discharge power is determined as the actual discharge power of the battery. Since the total power consumption and the discharge power should be equal at the same moment, if a signal of a certain path is delayed, then determining the maximum value of the total power consumption and the discharge power as the actual discharge power of the battery is less likely to cause over-discharge of the battery during subsequent adjustment. That is, the maximum value of these two signals of the total power consumption and the discharge power is more credible and can better represent the signal with the least delay.

[0077] Step 103: Compare the actual discharge power with the maximum discharge power of the battery, and determine whether to adjust the available power of the target electrical device according to the comparison result to avoid over-discharge of the battery.

[0078] Among them, the target electrical device is an electrical device with adjustable power consumption among all electrical devices powered by the battery.

[0079] Among them, after determining the actual discharge power of the battery, comparing the actual discharge power with the maximum discharge power of the battery can determine whether the battery is about to be over-discharged. According to the comparison result, when the battery is about to be over-discharged, adjust the available power of the target electrical device to avoid the total power consumption of all electrical devices powered by the battery in the vehicle at the next moment (that is, the sum of the actual available power of the adjusted target electrical device and the power consumption of other electrical devices) exceeding the maximum discharge power of the battery, thus avoiding over-discharge of the battery.

[0080] Among them, since at the same moment, the total power consumption of all electrical devices powered by the battery in the vehicle is equal to the discharge power of the battery, and the power consumption of some electrical devices in the vehicle, such as high-voltage accessories, needs to be guaranteed preferentially. Therefore, comparing the actual discharge power with the maximum discharge power of the battery, and according to the comparison result, when the battery is about to discharge, adjusting the available power of the target electrical device with adjustable power consumption in the vehicle can avoid over-discharge of the battery.

[0081] In the embodiment of the present invention, by obtaining two signals, namely, the total power consumption of all electrical devices powered by the battery in the vehicle and the discharge power of the battery, based on these two signals of the total power consumption and the discharge power, the actual discharge power of the battery that can represent the actual total power consumption of all electrical devices is determined, that is, the actual discharge power of the battery with the minimum signal delay. The actual discharge power of the battery is compared with the maximum discharge power of the battery, and whether to adjust the available power of the target electrical device is judged according to the comparison result. This is to avoid directly comparing the discharge power of the battery with the maximum discharge power of the battery. When subsequent judgments and adjustments are made according to the comparison result, if the signal of the discharge power of the battery is delayed, the obtained comparison result and judgment result may both be incorrect, which may further cause the discharge power output by the battery based on the available power of the target electrical device to be higher than the maximum discharge power of the battery, resulting in over-discharge of the battery, and further leading to abnormal over-discharge protection of the battery, triggering over-discharge protection of the battery, resulting in power-off under fault, and even causing irreversible damage to the battery.

[0082] As an embodiment of the present invention, referring to Figure 2 , the implementation process of step 103 may include:

[0083] Step 201, obtain the available power of all drive motors based on the maximum discharge power.

[0084] In this embodiment, among all the electrical devices powered by the battery in the vehicle, the power consumption of the high-voltage accessories needs to be guaranteed first. Therefore, the available power of all drive motors can be obtained based on the maximum discharge power of the battery and the power consumption of the high-voltage accessories. When the battery is about to be over-discharged, the available power of all drive motors is adjusted based on the difference between the maximum discharge power of the battery and the actual discharge power of the battery, so that the discharge power output according to the adjusted actual available power of all drive motors does not exceed the maximum discharge power of the battery.

[0085] Optionally, referring to Figure 3 , the implementation process of obtaining the available power of all drive motors based on the maximum discharge power in step 201 may include:

[0086] Step 301, obtain the highest temperature and the lowest temperature of the battery, the actual state of charge of the battery, and the actual power consumption of the high-voltage accessories among all electrical devices.

[0087] Step 302, determine the temperature correction coefficient and the state-of-charge correction coefficient according to the highest temperature, the lowest temperature, the actual state of charge, and the preset correction coefficient table.

[0088] Step 303, correct the maximum discharge power according to the temperature correction coefficient and the state-of-charge correction coefficient to determine the maximum dynamic discharge power of the battery.

[0089] Step 304: Calculate the difference between the maximum dynamic discharge power and the actual power consumption to obtain the available power of all drive motors.

[0090] In this embodiment, when obtaining the available power of all drive motors, the influence of extremely cold or extremely hot environments on the maximum discharge power of the battery and the limitation of the maximum discharge power of the battery by the actual state of charge of the battery are considered. The available power of all drive motors is calculated by the following formula:

[0091] PElecSysAvl = DynPwrBattMax * FacTBatt * FacBattSOC - PwrHVBoard;

[0092] Wherein, PElecSysAvl represents the available power of all drive motors, DynPwrBattMax represents the maximum discharge power of the battery, FacTBatt represents the temperature correction coefficient, FacBattSOC represents the state of charge correction coefficient. The preset correction coefficient table, that is, the relationship table between temperature and temperature correction coefficient, and the relationship table between state of charge and state of charge correction coefficient, can be determined according to different types of batteries installed in different vehicle models. In this embodiment, the maximum discharge power of the battery is corrected by the temperature correction coefficient, which can prevent hardware damage or battery failure shutdown caused by too high battery charging or discharging power for extremely cold and extremely hot working conditions. The maximum discharge power of the battery is corrected by the state of charge correction coefficient. When the actual state of charge of the battery is relatively high, the minimum available power (or dynamic recovery power) of all drive motors can be limited to prevent the actual state of charge of the battery from being too high; when the actual state of charge of the battery is relatively low, the available power of all drive motors is limited. On the one hand, it can prevent the actual state of charge of the battery from continuously decreasing and triggering protection (fault shutdown). On the other hand, when the actual state of charge of the battery is relatively low, the maximum discharge power of the battery will fluctuate greatly, resulting in fluctuations in the available power of all drive motors (causing motor torque fluctuations and vehicle jerks). The correction of the maximum discharge power of the battery by the state of charge correction coefficient can reduce the fluctuations and ensure smooth output of the vehicle torque at a relatively low state of charge.

[0093] Exemplarily, for a hybrid vehicle, the operable range of the state of charge of the battery under normal driving conditions is generally about 30 - 70. The actual state of charge of the battery can be compared with the operable range of the state of charge of the battery under normal driving conditions to determine whether the actual state of charge of the battery is relatively high or low.

[0094] Exemplarily, the temperature correction coefficient table in the preset correction coefficient table can be as shown in Table 1:

[0095] Table 1

[0096] Temperature -20 -18 -15 -12 -10 -5 0 20 40 45 50 55 58 60 FacTBatt 0 0.2 0.4 0.6 0.8 0.9 1 1 0.9 0.7 0.6 0.5 0.2 0

[0097] Among them, as shown in Table 1, after obtaining the maximum temperature and the minimum temperature of the battery, when the temperature is high, the maximum temperature is used to determine the temperature correction coefficient, and when the temperature is low, the minimum temperature is used to determine the temperature correction coefficient. Exemplarily, if the maximum temperature of the battery is 5°C and the minimum temperature of the battery is 0°C, then the battery is in a critical situation in an extremely cold environment, and the temperature correction coefficient is determined to be 1 according to the minimum temperature of the battery. Similarly, if the maximum temperature of the battery is still 5°C and the minimum temperature of the battery is -5°C, then the battery is in an extremely cold environment and the temperature correction coefficient is 0.9.

[0098] Exemplarily, the state of charge correction coefficient table in the preset correction coefficient table can be as shown in Table 2:

[0099] Table 2

[0100] SOC 0 5 10 11 12 13 14 14.5 15 FacBattSOC 0 0 0 0.1 0.3 0.5 0.7 0.9 1

[0101] As shown in Table 2, assuming that the actual state of charge of the battery just reaches the strong charge point 15, the state of charge correction coefficient is 1.

[0102] Optionally, on the basis of the above embodiments, at the same moment, the reserved power of the heating device can also be obtained; and then according to P es = P' max - P hv - P ptc , the available power of all drive motors is obtained.

[0103] Among them, P es represents the available power, P' max represents the maximum dynamic discharge power, P hv represents the actual power consumption, and P ptc represents the reserved power of the heating device.

[0104] Corresponding to the above embodiments, that is, according to:

[0105] PElecSysAvl = DynPwrBattMax * FacTBatt * FacBattSOC - PwrHVBoard - PwrResvPTC to obtain the available power. Here, PwrResvPTC = P ptc also represents the reserved power of the heating device.

[0106] When determining the available power of all drive motors in this embodiment, it mainly targets the characteristics of the air-conditioning heating resistor PTC. Since there is a large current impact at the moment when PTC is turned on and it is uncontrollable, therefore, the reserved power of the heating device corresponding to the PTC current impact can be calibrated for different air-conditioning models. When PTC requests to be turned on, subtract the reserved power of the corresponding heating device and continue for a preset time (such as 5 s) to prevent over-discharge of the battery caused by the turning on of PTC.

[0107] Exemplarily, the reserved power of the heating device within 5 minutes of PTC enabling can be 8 KW.

[0108] Optionally, on the basis of the above embodiment, at the same moment, a preset power adjustment amount can also be obtained; and then according to P es = P′ max - P hv - P ptc - P0, the available power of all drive motors is obtained.

[0109] Wherein, P0 represents the preset power adjustment amount.

[0110] Corresponding to the above embodiment, that is, according to:

[0111] PElecSysAvl = DynPwrBattMax * FacTBatt * FacBattSOC - PwrHVBoard - PwrResvPTC - offset(Calibration) to obtain the available power. Here, offset(Calibration) = P0 also represents the preset power adjustment amount.

[0112] When determining the available power of all drive motors in this embodiment, the preset power adjustment amount calibrated by the calibration engineer can also be obtained, and the available power of all drive motors is obtained by subtracting this preset power adjustment amount, so as to forcibly reduce the consumption of all drive motors through this preset power adjustment amount.

[0113] Exemplarily, this preset power adjustment amount can be 5 KW.

[0114] Step 202, calculate the first power difference between the maximum discharge power and the actual discharge power.

[0115] Step 203, compare the first power difference with the proportional-integral regulation activation threshold.

[0116] Step 204, if the first power difference is less than the proportional-integral regulation activation threshold, perform proportional-integral regulation on the available power according to the first power difference, and determine the actual available power of all drive motors according to the result of the proportional-integral regulation.

[0117] Exemplarily, the first power difference between the maximum discharge power and the actual discharge power can be calculated by PwrDelta = DynPwrBattMax - PbattAct, where PwrDelta represents the first power difference.

[0118] After calculating the first power difference, it can be compared with the proportional-integral activation threshold to determine whether the battery is about to be over-discharged. That is, it is judged whether the first power difference is less than the proportional-integral regulation activation threshold. If the first power difference is less than the proportional-integral activation threshold, proportional-integral regulation is performed on the available power of all drive motors obtained in the above step 201, and the actual available power of all drive motors is determined according to the result of the proportional-integral regulation.

[0119] Exemplarily, it can be judged whether the first power difference PwrDelta is less than a preset power threshold and whether the duration of being less than the preset power threshold is greater than a preset time to determine whether the battery is about to be over-discharged. The preset power threshold can be obtained through calibration and can be, for example, 5 Kw.

[0120] Exemplarily, if the first power difference is less than the preset power threshold and the duration of being less than the preset power threshold is greater than the preset time, the battery is about to be over-discharged, and proportional-integral regulation (Proportional Integral Controller, PI) is activated. The available power of all drive motors is regulated through PI regulation, and the actual available power of all drive motors is determined according to the result of the PI regulation.

[0121] Exemplarily, the available power can be regulated by PI through the following formula:

[0122] PelecSysAvlPI = PElecSysAvl + P * PwrDelta + I * ∫PwrDeltadt;

[0123] Among them, PelecSysAvlPI represents the actual available power of all drive motors after PI regulation, P represents the proportional parameter, and I represents the integral parameter. The proportional parameter and the integral parameter can be calibrated based on different battery types. For example, for a 300V lithium iron phosphate battery, the proportional parameter and the integral parameter corresponding to different first power differences are shown in Table 3.

[0124] Table 3

[0125] Pwrdelta -5 -4 -3 -2 -1 0 1 2 3 4 5 P 0.9 0.8 0.7 0.6 0.5 0 -0.5 -0.6 -0.7 -0.8 -0.9 I 0.9 0.8 0.7 0.6 0.5 0 -0.5 -0.6 -0.7 -0.8 -0.9

[0126] Optionally, after comparing the first power difference with the proportional-integral regulation activation threshold, it may further include: if the first power difference is greater than or equal to the proportional-integral regulation activation threshold, determining the available power as the actual available power of all drive motors.

[0127] In this embodiment, if the first power difference is greater than or equal to the proportional-integral regulation activation threshold, it means that the battery will not be about to over-discharge. Then, the available power of all drive motors obtained in step 201 can be directly used as the actual available power of all drive motors. Since when obtaining the available power of all drive motors in step 201, the influence of the highest temperature, lowest temperature, and actual state of charge of the battery on the maximum discharge power of the battery, as well as the reserved power of the PTC (i.e., the reserved power of the heating device) and the preset power adjustment amount can be considered. Therefore, when the battery is not in the working condition of about to over-discharge, determining the available power as the actual available power of all drive motors can also avoid over-discharge of the discharge power output by the battery based on the actual available power of all motors.

[0128] Exemplarily, if the first power difference is not less than the preset power threshold, or the time when the first power difference is less than the preset power threshold does not reach the preset time, the available power of all drive motors obtained in step 201 can be directly used as the actual available power of all drive motors.

[0129] In the embodiment of the present invention, the available power of all drive motors is obtained through the maximum discharge power of the battery, and then the first power difference between the maximum discharge power and the actual discharge power is calculated. When the first power difference is not less than the proportional-integral activation threshold, the available power of all drive motors obtained above is directly determined as the actual available power of all drive motors. When the first power difference is less than the proportional-integral activation threshold, the PI regulation is activated, and the available power of all drive motors is PI-regulated according to the first power difference. The actual available power of all drive motors is determined according to the result of the PI regulation. When it is detected that the actual discharge power of the battery is about to exceed the maximum discharge power of the battery, the available power of all drive motors can be gradually reduced through PI regulation until the PI regulation exits, and the actual available power of all drive motors is determined. The discharge power output by the battery is controlled according to the actual available power of all drive motors, so as to achieve the purpose of preventing the battery from over-discharging.

[0130] It should be understood that the magnitudes of the sequence numbers of the steps in the above embodiments do not mean the order of execution. The order of execution of each process should be determined according to its function and internal logic, and should not constitute any limitation to the implementation process of the embodiments of the present invention.

[0131] The following is the device embodiment of the present invention. For the details not described in detail therein, reference can be made to the corresponding method embodiment above.

[0132] Figure 4 The figure shows a schematic structural diagram of a battery over-discharge protection device provided by an embodiment of the present invention. For ease of description, only parts related to the embodiment of the present invention are shown and are described in detail as follows:

[0133] As Figure 4 shown, the battery over-discharge protection device includes: an acquisition module 41, a first processing module 42, and a second processing module 43.

[0134] The acquisition module 41 is configured to acquire the total power consumption of all electrical devices powered by the battery in the vehicle and the discharge power of the battery;

[0135] The first processing module 42 is configured to determine the actual discharge power of the battery according to the total power consumption and the discharge power; the actual discharge power represents the total actual power consumption of all electrical devices;

[0136] The second processing module 43 is configured to compare the actual discharge power with the maximum discharge power of the battery, and determine whether to adjust the available power of the target electrical device according to the comparison result to avoid over-discharging of the battery. The target electrical device is an electrical device whose power consumption can be adjusted among all electrical devices.

[0137] In the embodiment of the present invention, by acquiring two signals, namely, the total power consumption of all electrical devices powered by the battery in the vehicle and the discharge power of the battery, and according to these two signals of the total power consumption and the discharge power, the actual discharge power of the battery that can represent the total actual power consumption of all electrical devices is determined, that is, the actual discharge power of the battery with the smallest signal delay. The actual discharge power of the battery is compared with the maximum discharge power of the battery, and it is determined whether to adjust the available power of the target electrical device according to the comparison result. To avoid directly comparing the discharge power of the battery with the maximum discharge power of the battery, when subsequent judgment and adjustment are performed according to the comparison result, if the signal of the discharge power of the battery is delayed, both the obtained comparison result and judgment result may be incorrect, which may further cause the discharge power output by the battery based on the available power of the target electrical device to be higher than the maximum discharge power of the battery, resulting in over-discharging of the battery, and further leading to abnormal over-discharge protection of the battery, triggering over-discharge protection of the battery, resulting in power-off under fault, and even causing irreversible damage to the battery.

[0138] In a possible implementation manner, the first processing module 42 may be configured to determine the maximum value of the total power consumption and the discharge power as the actual discharge power of the battery.

[0139] In a possible implementation, the target electrical device includes all drive motors in a vehicle; the second processing module 43 can be used to obtain the available power of all drive motors based on the maximum discharge power; calculate the first power difference between the maximum discharge power and the actual discharge power; compare the first power difference with the proportional-integral regulation activation threshold; if the first power difference is less than the proportional-integral regulation activation threshold, perform proportional-integral regulation on the available power according to the first power difference, and determine the actual available power of all drive motors according to the result of the proportional-integral regulation.

[0140] In a possible implementation, after comparing the first power difference with the proportional-integral regulation activation threshold, if the first power difference is greater than or equal to the proportional-integral regulation activation threshold, the second processing module 43 can be used to determine the available power as the actual available power of all drive motors.

[0141] In a possible implementation, the second processing module 43 can be used to obtain the maximum temperature and minimum temperature of the battery, the actual state of charge of the battery, and the actual power consumption of high-voltage accessories among all electrical devices; determine the temperature correction coefficient and the state-of-charge correction coefficient according to the maximum temperature, minimum temperature, actual state of charge, and a preset correction coefficient table; correct the maximum discharge power according to the temperature correction coefficient and the state-of-charge correction coefficient to determine the maximum dynamic discharge power of the battery; calculate the difference between the maximum dynamic discharge power and the actual power consumption to obtain the available power of all drive motors.

[0142] In a possible implementation, the second processing module 43 can also be used to obtain the reserved power of the heating device; according to P es =P m ′ ax -P hv -P ptc , obtain the available power of all drive motors;

[0143] Among them, P es represents the available power, P m ′ ax represents the maximum dynamic discharge power, P hv represents the actual power consumption, P ptc represents the reserved power of the heating device.

[0144] In a possible implementation, the second processing module 43 can also be used to obtain a preset power adjustment amount; according to P es =P m ′ ax -P hv -P ptc -P0, obtain the available power of all drive motors;

[0145] Wherein, P0 represents a preset power adjustment amount.

[0146] In a possible implementation, all the electrical devices powered by the battery in the vehicle include all the drive motors and high-voltage accessories in the vehicle; the acquisition module 41 can be used to acquire the actual electrical power, actual mechanical power, and actual motor efficiency corresponding to each drive motor, as well as the actual power consumption of the high-voltage accessories; according to the actual mechanical power of each drive motor and the corresponding actual motor efficiency, calculate the efficiency-converted electrical power of each drive motor; calculate the sum of the efficiency-converted electrical powers of each drive motor to obtain the total first power consumption of all drive motors; calculate the sum of the actual electrical powers of each drive motor to obtain the total second power consumption of all drive motors; determine the maximum value between the total first power consumption and the total second power consumption as the current total power consumption of all drive motors; calculate the sum of the current total power consumption and the actual power consumption to obtain the total power consumption of all the electrical devices powered by the battery in the vehicle.

[0147] Figure 5 It is a schematic diagram of the controller provided by an embodiment of the present invention. As Figure 5 shown, the controller 5 of this embodiment includes: a processor 50, a memory 51, and a computer program 52 stored in the memory 51 and executable on the processor 50. When the processor 50 executes the computer program 52, it implements the steps in the above-mentioned embodiments of each battery over-discharge protection method, such as Figure 1 the steps 101 to 103 shown, or Figure 2 the steps 201 to 204 shown, or Figure 3 the steps 301 to 304 shown. Alternatively, when the processor 50 executes the computer program 52, it implements the functions of each module in the above-mentioned device embodiments, such as Figure 4 the functions of the modules 41 to 43 shown.

[0148] Exemplarily, the computer program 52 can be divided into one or more modules / units. One or more modules / units are stored in the memory 51 and executed by the processor 50 to complete the present invention. One or more modules / units can be a series of computer program instruction segments capable of performing specific functions, and these instruction segments are used to describe the execution process of the computer program 52 in the controller 5. For example, the computer program 52 can be divided into Figure 4 the modules 41 to 43 shown.

[0149] The controller 5 can be a vehicle's vehicle controller or other controllers for controlling the vehicle. The controller 5 may include, but is not limited to, the processor 50 and the memory 51. Those skilled in the art can understand, Figure 5This is only an example of the controller 5 and does not constitute a limitation on the controller 5. It may include more or fewer components than those shown in the figure, or combine certain components, or different components. For example, the controller may also include input / output devices, network access devices, buses, etc.

[0150] The so-called processor 50 may be a central processing unit (CPU), or may also be other general-purpose processors, digital signal processors (DSPs), application specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc.

[0151] The memory 51 may be an internal storage unit of the controller 5, such as the hard disk or memory of the controller 5. The memory 51 may also be an external storage device of the controller 5, such as a plug-in hard disk equipped on the controller 5, a smart media card (SMC), a secure digital (SD) card, a flash card, etc. Further, the memory 51 may also include both an internal storage unit and an external storage device of the controller 5. The memory 51 is used to store computer programs and other programs and data required by the controller. The memory 51 may also be used to temporarily store data that has been output or is to be output.

[0152] Those skilled in the art can clearly understand that, for the convenience and simplicity of description, only the above division of each functional unit and module is used as an example. In actual applications, the above functions can be assigned to different functional units and modules as needed, that is, the internal structure of the device is divided into different functional units or modules to complete all or part of the functions described above. Each functional unit and module in the embodiment may be integrated into a processing unit, or each unit may exist physically alone, or two or more units may be integrated into one unit. The above integrated unit may be implemented in the form of hardware or in the form of a software functional unit. In addition, the specific names of each functional unit and module are only for the convenience of mutual distinction and do not limit the protection scope of the present application. The specific working processes of the units and modules in the above system can refer to the corresponding processes in the foregoing method embodiments and will not be elaborated herein.

[0153] As another embodiment of the present invention, the present invention may further include a vehicle, which includes the controller of any of the above embodiments and has the same beneficial effects as the above controller, and will not be elaborated herein.

[0154] In the above embodiments, the descriptions of the respective embodiments have their own emphases. For parts not elaborated or recorded in a certain embodiment, reference may be made to the relevant descriptions of other embodiments.

[0155] Those of ordinary skill in the art can realize that the units and algorithm steps of the examples described in conjunction with the embodiments disclosed herein can be implemented by electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are executed in a hardware or software manner depends on the specific application and design constraints of the technical solution. Professional technicians can use different methods for each specific application to implement the described functions, but such implementation should not be considered to exceed the scope of the present invention.

[0156] In the embodiments provided by the present invention, it should be understood that the disclosed device / controller and method can be implemented in other ways. For example, the device / controller embodiments described above are merely illustrative. For example, the division of modules or units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the displayed or discussed couplings or direct couplings or communication connections to each other can be through some interfaces. The indirect couplings or communication connections of the devices or units can be in electrical, mechanical or other forms.

[0157] The units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they can be located in one place, or distributed to multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0158] In addition, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically alone, or two or more units can be integrated into one unit. The above integrated units can be implemented in the form of hardware or in the form of software functional units.

[0159] When the integrated module / unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on such an understanding, to implement all or part of the processes in the above-described embodiment methods of the present invention, it can also be completed by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium. When the computer program is executed by a processor, the steps of the above-described various battery over-discharge protection method embodiments can be implemented. Among them, the computer program includes computer program code, and the computer program code can be in the form of source code, object code, executable file, or some intermediate form, etc. The computer-readable medium can include: any entity or device capable of carrying computer program code, recording medium, USB flash drive, mobile hard disk, magnetic disk, optical disc, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signal, telecommunication signal, and software distribution medium, etc. It should be noted that the content included in the computer-readable medium can be appropriately increased or decreased according to the requirements of legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, the computer-readable medium does not include electrical carrier signals and telecommunication signals.

[0160] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention, and should all be included in the protection scope of the present invention.

Claims

1. A method for over-discharge protection of a battery, characterized in that, including: Obtaining the total power consumption of all electrical devices powered by the battery in the vehicle and the discharge power of the battery; Determining the actual discharge power of the battery according to the total power consumption and the discharge power; the actual discharge power represents the actual total power consumption of all electrical devices; Comparing the actual discharge power with the maximum discharge power of the battery, and judging whether to adjust the available power of the target electrical device according to the comparison result to avoid over-discharging of the battery, where the target electrical device is an electrical device whose power consumption can be adjusted among all electrical devices; Wherein, the determining the actual discharge power of the battery according to the total power consumption and the discharge power includes: Determining the maximum value of the total power consumption and the discharge power as the actual discharge power of the battery.

2. The battery over-discharge protection method according to claim 1, wherein The target electrical device includes all drive motors in the vehicle; The comparing the actual discharge power with the maximum discharge power of the battery and judging whether to adjust the available power of the target electrical device according to the comparison result includes: Obtaining the available power of all drive motors based on the maximum discharge power; Calculating a first power difference between the maximum discharge power and the actual discharge power; Comparing the first power difference with a proportional-integral regulation activation threshold; If the first power difference is less than the proportional-integral regulation activation threshold, performing proportional-integral regulation on the available power according to the first power difference, and determining the actual available power of all drive motors according to the result of the proportional-integral regulation.

3. The battery over-discharge protection method according to claim 2, wherein After comparing the first power difference with the proportional-integral regulation activation threshold, it further includes: If the first power difference is greater than or equal to the proportional-integral regulation activation threshold, determining the available power as the actual available power of all drive motors.

4. The battery over-discharge protection method according to claim 3, wherein The obtaining the available power of all drive motors based on the maximum discharge power includes: Obtaining the highest temperature and the lowest temperature of the battery, the actual state of charge of the battery, and the actual power consumption of high-voltage accessories among all electrical devices; Determining a temperature correction coefficient and a state-of-charge correction coefficient according to the highest temperature, the lowest temperature, the actual state of charge, and a preset correction coefficient table; Correcting the maximum discharge power according to the temperature correction coefficient and the state-of-charge correction coefficient to determine the maximum dynamic discharge power of the battery; Calculating the difference between the maximum dynamic discharge power and the actual power consumption to obtain the available power of all drive motors.

5. The battery over-discharge protection method according to claim 4, wherein It further includes: Obtaining the reserved power of the heating device; The calculating the difference between the maximum dynamic discharge power and the actual power consumption to obtain the available power of all drive motors includes: According to , obtain the available power of all drive motors; Among them, represents the available power, represents the maximum dynamic discharge power, represents the actual power consumption, represents the reserved power of the heating device.

6. The battery over-discharge protection method according to claim 5, characterized in that, It further includes: Obtaining a preset power adjustment amount; The calculating the difference between the maximum dynamic discharge power and the actual power consumption to obtain the available power of all drive motors includes: According to , obtain the available power of all drive motors; Wherein, represents the preset power adjustment amount.

7. The battery over-discharge protection method according to any one of claims 1-6, characterized in that All electrical devices powered by the battery in the vehicle include all drive motors and high-voltage accessories in the vehicle; The obtaining the total power consumption of all electrical devices powered by the battery in the vehicle includes: Obtain the actual electric power, actual mechanical power, and actual motor efficiency corresponding to each drive motor, as well as the actual power consumption of the high-voltage accessory; Calculate the efficiency-converted electric power of each drive motor according to the actual mechanical power of each drive motor and the corresponding actual motor efficiency; Calculate the sum of the efficiency-converted electric powers of each drive motor to obtain the total first power consumption of all drive motors; Calculate the sum of the actual electric powers of each drive motor to obtain the total second power consumption of all drive motors; Determine the maximum value between the total first power consumption and the total second power consumption as the current total power consumption of all drive motors; Calculate the sum of the current total power consumption and the actual power consumption to obtain the total power consumption of all electrical devices powered by the battery in the vehicle.

8. A battery over-discharge protection device, characterized in that, Including: An acquisition module for acquiring the total power consumption of all electrical devices powered by the battery in the vehicle and the discharge power of the battery; A first processing module for determining the actual discharge power of the battery according to the total power consumption and the discharge power; The actual discharge power represents the actual total power consumption of all electrical devices; A second processing module for comparing the actual discharge power with the maximum discharge power of the battery, and judging whether to adjust the available power of the target electrical device according to the comparison result to avoid over-discharging of the battery, where the target electrical device is an electrical device whose power consumption can be adjusted among all electrical devices; Among them, the first processing module is specifically used for: Determining the maximum value between the total power consumption and the discharge power as the actual discharge power of the battery.

9. A vehicle, comprising a controller, the controller including a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, the steps of the method described in any one of claims 1 to 7 above are implemented.

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