A power battery power protection method, device and vehicle

Abstract

The application provides a power battery power protection method, comprising: acquiring allowed power information of a power battery at an actual state of charge; the allowed power information at least comprises peak charging and discharging power and continuous charging and discharging power; in the case that actual power of the power battery exceeds the peak charging and discharging power, timing running time of the actual power, and after the running time reaches a first preset time, switching available effective power of the power battery to a preset power value; wherein the preset power value is greater than the continuous charging and discharging power. In this way, through a reasonable power switching strategy, vehicle power can be ensured to be smooth, driving jerk caused by forced power reduction can be avoided, and the battery can be protected from overcharging and overdischarging. The application also discloses a power battery power protection device and a vehicle.

Description

Technical Field

[0001] This application relates to the field of power battery technology, and in particular to a power battery power protection method, device and vehicle. Background Technology

[0002] As an energy storage component of new energy vehicles, the power battery influences the sustainable development of the new energy industry. Relevant methods for estimating battery SOP (State of Charge) involve looking up the peak charge / discharge power and continuous charge / discharge power of the battery pack based on its current temperature and SOC during vehicle operation. This information is then sent to the vehicle controller for processing. However, if the actual power output during vehicle operation exceeds the peak discharge power and exceeds the timeout period, the power output will be forcibly reduced to the continuous discharge power. This results in the power demand not being met when the vehicle is operating at high power, leading to poor power smoothness and impacting the driving experience. Furthermore, the high discharge power and long discharge time, combined with high recharge power, can lead to overcharging, over-discharging, and even thermal runaway of the power battery. Summary of the Invention

[0003] This application provides a power battery power protection method, device, and vehicle. The method involves acquiring the allowable power information of the power battery under its actual state of charge. This allowable power information includes at least peak charge / discharge power and continuous charge / discharge power. When the actual power of the power battery exceeds the peak charge / discharge power, the operating time of the actual power is timed. After the operating time reaches a first preset time, the available effective power of the power battery is switched to a preset power value, wherein the preset power value is greater than the continuous charge / discharge power. This reasonable power switching strategy ensures smooth vehicle power delivery, avoids driving jerks caused by forced power reduction, and protects the battery from overcharging and over-discharging.

[0004] The technical solution of this application embodiment is implemented as follows:

[0005] This application provides a power battery power protection method, the method comprising:

[0006] Obtain the allowable power information of the power battery under actual state of charge; the allowable power information includes at least the peak charge / discharge power and the continuous charge / discharge power;

[0007] When the actual power of the power battery exceeds the peak charge / discharge power, the operating time of the actual power is timed.

[0008] After the running time reaches a first preset time, the available effective power of the power battery is switched to a preset power value; wherein the preset power value is greater than the continuous charging and discharging power.

[0009] In some embodiments of this application, the preset power value includes at least a first gradient power value and a second gradient power value; wherein the first gradient power value is greater than the second gradient power value; the step of switching the available effective power of the power battery to the preset power value after the running time reaches a first preset time includes: switching the available effective power of the power battery to the first gradient power value after the running time reaches a first sub-preset time; the first sub-preset time is less than the first preset time; when the actual power of the power battery exceeds the first gradient power value and runs for a second sub-preset time, it is determined that the running time has reached the first preset time; after the running time reaches the first preset time, the available effective power of the power battery is switched to the second gradient power value.

[0010] In this way, after providing the allowable power information of the power battery, when the actual power of the power battery exceeds the peak charging and discharging power, the available effective power of the power battery can be switched to a preset power with a gradient decrease, which can further enhance the power connection stability of the vehicle when it is in a high-power working state and improve the driving experience.

[0011] In some embodiments of this application, the power battery power protection method further includes: when the actual power of the power battery is lower than the continuous charge and discharge power, timing the running time of the actual power, and after reaching a second preset time, restoring the available effective power of the power battery to the peak charge and discharge power.

[0012] In this way, after running at low power for a preset period of time, it can quickly recover to the peak charging and discharging power, giving full play to the performance of the power battery.

[0013] In some embodiments of this application, the power battery power protection method further includes: determining an overpower protection threshold that matches the allowed power information; and controlling the power battery to perform a recharge operation or a discharge operation according to the overpower protection threshold.

[0014] This can further prevent the abuse of power battery cells, avoid irreversible conditions such as thermal runaway, and ensure the performance of the entire vehicle.

[0015] In some embodiments of this application, the power battery power protection method further includes: determining a target single-cell voltage protection value that matches the allowable power information, considering the influence of single-cell voltage factors; and controlling the power battery to perform a recharge operation or a discharge operation according to the target single-cell voltage protection value.

[0016] Thus, considering the potential delay in the frequency of hardware data updates during vehicle operation, which may prevent the allowable power information obtained from the lookup table from being completely timely and reliable, the voltage of each individual cell in the power battery is estimated and protected.

[0017] In some embodiments of this application, the target cell voltage protection value that matches the allowed power information includes: the target cell voltage protection value in recharge mode. Determining the target cell voltage protection value that matches the allowed power information includes: looking up the first DC internal resistance of the power battery at maximum charge and highest temperature using a charge-DC internal resistance table, and the second DC internal resistance of the power battery at maximum charge and lowest temperature, comparing the smaller of the two as the DC internal resistance in recharge mode; calculating the first polarization voltage under different real-time pulse currents in recharge mode; and summing the first polarization voltage with the open-circuit voltage in recharge mode to obtain the target cell voltage protection value in recharge mode.

[0018] In some embodiments of this application, the target cell voltage protection value further includes a target cell voltage protection value under discharge mode. Determining the target cell voltage protection value that matches the allowable power information includes: looking up the third DC internal resistance of the power battery at maximum charge and highest temperature using a charge-DC internal resistance table, and the fourth DC internal resistance of the power battery at maximum charge and lowest temperature, comparing the smaller of the two as the DC internal resistance under discharge mode; calculating the second polarization voltage under different real-time pulse currents in the discharge mode; summing the second polarization voltage with the open-circuit voltage under discharge mode to obtain the target cell voltage protection value under discharge mode; wherein the open-circuit voltage under recharge mode and the open-circuit voltage under discharge mode are obtained by looking up a table based on the charge-open-circuit voltage curve.

[0019] In this way, considering the safety of the battery system, the voltage of the individual power battery cells is estimated and protected, avoiding overcharging and over-discharging faults of the battery system caused by excessive use of the load side.

[0020] In some embodiments of this application, the power battery power protection method further includes: determining the cell voltage under different temperature conditions, and limiting the power of the power battery by adopting a graded restriction method according to the preset cell voltage threshold under different temperature conditions.

[0021] In this way, by implementing graded self-protection of individual cell voltages, system abuse under fault conditions is avoided, battery system safety is protected, and battery system life is extended.

[0022] This application provides a power battery power protection device, including:

[0023] An information acquisition unit is used to acquire the allowable power information of the power battery under actual state of charge; the allowable power information includes at least the peak charge / discharge power and the continuous charge / discharge power.

[0024] A charge / discharge power switching unit is used to time the running time of the actual power when the actual power of the power battery exceeds the peak charge / discharge power, and after the running time reaches a first preset time, to switch the available effective power of the power battery to a preset power value; wherein the preset power value is greater than the continuous charge / discharge power.

[0025] This application provides a vehicle, including a power system and a controller;

[0026] The power system includes at least a power battery;

[0027] The controller is used to execute the aforementioned power battery protection method in the vehicle.

[0028] The embodiments of this application have the following beneficial effects:

[0029] This embodiment of the application, when the actual power of the power battery exceeds the peak charge / discharge power, times the running time of the actual power. After the running time reaches a preset time, the available effective power of the power battery is switched to a preset power value; wherein, the preset power value is greater than the continuous charge / discharge power. In this way, through a reasonable power switching strategy, the smooth power of the entire vehicle can be ensured, avoiding the driving jerks caused by forcibly reducing power, while protecting the battery from overcharging and over-discharging. Attached Figure Description

[0030] Figure 1 A schematic flowchart of a power battery power protection method provided in an embodiment of this application;

[0031] Figure 2 A schematic flowchart illustrating another power battery power protection method provided in this application embodiment;

[0032] Figure 3 A schematic flowchart illustrating another power battery power protection method provided in this application embodiment;

[0033] Figure 4 A schematic diagram illustrating the process of redundant fault protection in the power battery power protection method provided in this application embodiment;

[0034] Figure 5 This is a flowchart illustrating the process of determining the target cell voltage protection value in the recharge mode of the power battery power protection method provided in the embodiments of this application.

[0035] Figure 6 A flowchart illustrating the process of determining the target cell voltage protection value under discharge mode in the power battery power protection method provided in this application embodiment;

[0036] Figure 7 This is a schematic diagram of the structure of the power battery power protection device provided in the embodiments of this application;

[0037] Figure 8 This is a schematic diagram of the vehicle structure provided in an embodiment of this application. Detailed Implementation

[0038] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application are further described in detail below with reference to the accompanying drawings and embodiments. The described embodiments should not be regarded as limitations on this application. All other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0039] In the following description, references to "some embodiments" refer to a subset of all possible embodiments. It is understood that "some embodiments" may be the same or different subsets of all possible embodiments and may be combined with each other without conflict. The terms "first / second / third" are used merely to distinguish similar objects and do not represent a specific ordering of objects. It is understood that "first / second / third" may be interchanged in a specific order or sequence where permitted, so that the embodiments of this application described herein can be implemented in an order other than that illustrated or described herein.

[0040] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. The terminology used herein is for descriptive purposes only and is not intended to limit the scope of this application.

[0041] The technical solution of this application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0042] The State of Power (SOP) of a power battery system represents the amount of electricity the battery can use per unit time, reflecting the battery's ability to recharge / discharge. SOP is typically divided into peak power and continuous power based on duration. Peak power is used for short-term applications such as starters, while continuous power is used for longer-duration applications such as acceleration and energy recovery. If the battery continues to discharge at high power, the battery temperature will rise rapidly, damaging the battery's internal structure. In severe cases, it can lead to over-discharge of the power battery and even thermal runaway.

[0043] The battery management system (BMS) of a power battery can estimate the maximum power that an electric vehicle can provide at the next moment and under continuous high current. During vehicle operation, existing technologies adjust the battery's power usage by sending a single maximum allowable power through the BMS. Related methods for estimating the battery's State of Charge (SOP) involve querying two-dimensional curves of SOC versus peak charge / discharge power (or continuous charge / discharge power) at different temperatures obtained during laboratory testing, based on the battery pack's current temperature and State of Charge (SOC) during vehicle operation. This yields the battery pack's peak charge / discharge power and continuous charge / discharge power at that moment, which are then sent to the vehicle controller for its use. Specifically, when the actual power during vehicle operation is lower than the continuous power, the SOP estimation of the battery management system uses the peak charge and discharge power to estimate the maximum allowable power. When the actual power is higher than the continuous power for a certain period of time, the SOP estimation switches to using the continuous charge and discharge power to estimate the maximum allowable power. When the actual power during vehicle operation is greater than the peak discharge power, the vehicle discharges at the peak discharge power and is timed. After the timeout, the power is forcibly reduced to the continuous discharge power. When the vehicle is in a high-power operating state, the forced power reduction not only fails to meet the vehicle's power demand, but also results in poor power smoothness of the entire vehicle, affecting the vehicle's drivability.

[0044] Based on this, some embodiments of this application provide a power battery power protection method, device, and vehicle. This method acquires the allowable power information of the power battery under its actual state of charge; the allowable power information includes at least peak charge / discharge power and continuous charge / discharge power; when the actual power of the power battery exceeds the peak charge / discharge power, the operating time of the actual power is timed; after the operating time reaches a preset time, the available effective power of the power battery is switched to a preset power value; wherein the preset power value is greater than the continuous charge / discharge power. In this way, through a reasonable power switching strategy, the smoothness of the vehicle's power delivery can be ensured, avoiding the driving jerks caused by forced power reduction, while also protecting the battery from overcharging and over-discharging.

[0045] Based on this, this embodiment provides a power battery power protection method, such as... Figure 1 The diagram shown is a flowchart illustrating a power battery power protection method provided in an embodiment of this application. (Refer to...) Figure 1 The steps shown are explained as follows:

[0046] Step S101: Obtain the allowable power information of the power battery under actual state of charge; the allowable power information includes at least the peak charge / discharge power and the continuous charge / discharge power.

[0047] In some embodiments of this application, the power battery may be an energy storage component deployed on a vehicle. "Vehicle" can refer to a motor vehicle, and may be any type of vehicle such as a large vehicle, a small vehicle, or a special-purpose vehicle.

[0048] In some embodiments of this application, the power battery can be any one of lithium battery, lead-acid battery, nickel-metal hydride battery, or hydrogen fuel cell. Lithium battery can refer to ternary lithium battery, lithium iron phosphate battery, lithium cobalt oxide battery, or lithium manganese oxide battery.

[0049] In some embodiments of this application, the permissible power information of the power battery under actual state of charge can be obtained by looking up a table based on temperature and SOC, or by looking up a mapping table of voltage and current and then converting it into power. In some feasible embodiments, the table lookup method based on temperature and SOC involves obtaining a mapping table of maximum permissible power (MAP) for different temperatures and preset states of charge based on laboratory tests. Then, based on the highest and lowest temperatures, maximum and minimum charge of the power battery during actual vehicle operation (i.e., when the power battery is under actual state of charge), a first available power corresponding to the highest temperature and a second available power corresponding to the lowest temperature are obtained by linear interpolation. The smaller of the absolute values ​​of the first and second available power is taken as the permissible power information. The obtained maximum permissible power mapping table for the power battery under different temperatures and preset states of charge can be obtained by conducting multiple tests on a power battery test bench, sequentially testing each preset state of charge power battery at multiple preset temperatures, and recording the permissible power obtained from each test.

[0050] In some embodiments of this application, the power battery generally includes multiple individual cells. It should be noted that the temperature of each part of the power battery is not entirely the same during use; the highest temperature of the power battery can be the temperature value of the part with the highest temperature, and the lowest temperature of the power battery can be the temperature value of the part with the lowest temperature.

[0051] Step S102: When the actual power of the power battery exceeds the peak charge / discharge power, time the running time of the actual power.

[0052] In some embodiments of this application, the actual power is the real-time power during the operation of the vehicle where the power battery is deployed.

[0053] Step S103: After the running time reaches the first preset time, the available effective power of the power battery is switched to a preset power value; wherein the preset power value is greater than the continuous charging and discharging power.

[0054] In some embodiments of this application, the first preset time refers to the maximum time that the power battery can sustain when operating at actual power.

[0055] In some embodiments of this application, the preset power value is the operating power preset in the battery management system of the power battery. This preset power value is greater than the continuous charge / discharge power obtained from a lookup table, and less than the peak charge / discharge power obtained from a lookup table. It should be noted that when the maximum allowable power of the power battery is the peak charge / discharge power, for actual power exceeding the peak charge / discharge power, this application embodiment is not limited to the fixed operating time defined by the peak power table. Instead, it presets the operating time that the power battery can currently withstand, thereby reserving some space for adjusting the actual power to the preset power to fully utilize the battery's discharge or recycling performance.

[0056] This application provides a power battery power protection method. It acquires the allowable power information of the power battery under its actual state of charge. When the actual power of the power battery exceeds the peak charge / discharge power, it times the running time of the actual power. After the running time reaches a preset time, it switches the available effective power to a preset power value, wherein the preset power value is greater than the continuous charge / discharge power. In this way, through a reasonable power switching strategy, it can ensure smooth vehicle power delivery, avoid driving jerks caused by forced power reduction, and protect the battery from overcharging and over-discharging.

[0057] In some embodiments, the preset power value includes at least a first gradient power value and a second gradient power value, wherein the first gradient power value is greater than the second gradient power value. Based on the obtained allowable power information of the power battery under actual state of charge, firstly, after the running time reaches a first sub-preset time, the available effective power of the power battery is switched to the first gradient power value; wherein the first sub-preset time is less than the first preset time; then, when the actual power of the power battery exceeds the first gradient power value and the running time reaches a second sub-preset time, it is determined that the running time has reached the first preset time; after the running time reaches the first preset time, the available effective power of the power battery is switched to the second gradient power value. In this way, after providing the allowable power information of the power battery, when the actual power of the power battery exceeds the peak charge and discharge power, by switching the available effective power of the power battery to a gradient-decreasing preset power, the power connection stability during high-power operation of the vehicle can be further enhanced, resulting in a better driving experience. That is to say, step S103 provided in the above embodiment can be implemented by the following steps S201 and S203, such as... Figure 2 The diagram shown is a flowchart illustrating another power battery power protection method provided in this application embodiment. Figure 2 The steps shown are explained as follows:

[0058] Step S201: After the running time reaches the first sub-preset time, the available effective power of the power battery is switched to the first gradient power value; the first sub-preset time is less than the first preset time.

[0059] In some embodiments of this application, the running time is the running time after the actual power of the power battery exceeds the peak charge and discharge power, that is, the maximum time that the power battery can continue to run when it exceeds the peak charge and discharge power.

[0060] In some embodiments of this application, the first preset time can be 5-10 seconds.

[0061] In some feasible implementations, the peak charge / discharge power is the 5s power SOP in the MAP table, and the first preset time can be 5s. For example, if the actual power of the power battery exceeds the 5s power SOP (i.e., the peak charge / discharge power), the running time of the actual power is timed, and after the running time reaches 5s, the available effective power is switched to the first gradient power value. For example, the first gradient power value can be the 10s power SOP in the MAP table.

[0062] Step S202: When the actual power of the power battery exceeds the first gradient power value and the operation reaches the second sub-preset time, it is determined that the operation time has reached the first preset time.

[0063] In some embodiments of this application, the second sub-preset time can be a preset duration in the battery management system of the power battery. For example, the second sub-preset time can be 5-10 seconds.

[0064] In some feasible implementations, the first gradient power value can be the 10s power SOP in the MAP table. After the power battery operates at an actual power exceeding the 10s power SOP for 10 seconds, the available effective power is switched to the second gradient power value. For example, the second gradient power value can be the 30s power SOP in the MAP table. Step S203: After the operating time reaches a first preset time, the available effective power of the power battery is switched to the second gradient power value.

[0065] In some embodiments of this application, the first preset time includes at least a first time period from the start of timing when the power battery operates to a first preset sub-time node, a second time period from the first preset sub-time node until the actual power reaches a first gradient power value, and a third time period from when the actual power of the power battery reaches the first gradient power value until the second preset sub-time node. The first preset time may be a duration preset by the battery management system of the power battery.

[0066] In some embodiments of this application, the second gradient power value may be the continuous charge and discharge power in the MAP table.

[0067] It should be noted that the allowable power information of the power battery under actual state of charge may include peak charging power, continuous charging power, peak discharging power, and continuous discharging power. For ease of explanation, the following embodiments will be exemplarily described for recharge mode and discharge mode respectively, so as to provide an exemplary explanation of the protection methods under different modes.

[0068] In some feasible implementations, when the vehicle is in recharge mode, the recharge power switching strategy is as follows: Based on the peak charging power and continuous charging power of the power battery under actual state of charge, if the actual recharge power of the power battery exceeds the 5s power SOP, the running time of the actual recharge power is timed. After the running time reaches 5s, the available effective power is switched to the 10s power SOP; if the actual recharge power of the power battery exceeds the 10s power SOP and runs for 10s, the available effective power is switched to the continuous charging power.

[0069] In some feasible implementations, when the vehicle is in discharge mode, the discharge power switching strategy is as follows: Based on the peak discharge power and continuous discharge power of the power battery under actual state of charge, if the actual discharge power of the power battery exceeds the 5s power SOP, the running time of the actual discharge power is timed. After the running time reaches 5s, the available effective power is switched to the 10s power SOP; if the actual discharge power of the power battery exceeds the 10s power SOP and the running time reaches 10s, the available effective power is switched to continuous discharge power.

[0070] In this way, after providing the allowable power information of the power battery, when the actual power of the power battery exceeds the peak charging and discharging power, the available effective power of the power battery can be switched to a preset power with a gradient decrease, which can further enhance the power connection stability of the vehicle when it is in a high-power working state and improve the driving experience.

[0071] In this embodiment, after switching the actual power of the power battery to the second gradient power value, the relationship between the actual power and the continuous charge / discharge power can be determined. When the actual power is lower than the continuous charge / discharge power, the running time of the actual power is timed. After reaching the second preset time, the available effective power of the power battery is restored to the peak charge / discharge power. That is, the power battery power protection method provided in this embodiment, after executing step S102 provided in the above embodiment, can also execute the following step 301, such as... Figure 3 The diagram shown is a flowchart illustrating another power battery power protection method provided in this application embodiment. Figure 3The steps shown are explained below:

[0072] Step S301: When the actual power of the power battery is lower than the continuous charge and discharge power, the running time of the actual power is timed, and after the second preset time is reached, the available effective power of the power battery is restored to the peak charge and discharge power.

[0073] In some embodiments of this application, the second preset time may be a preset duration in the battery management system of the power battery. For example, the second preset time may be 20-60 seconds.

[0074] In some feasible implementations, the peak charge / discharge power can be the 5s power SOP in the MAP table. In this way, after operating at low power for a preset period of time, the peak charge / discharge power can be quickly restored, fully utilizing the performance of the power battery.

[0075] In this embodiment of the application, to further prevent the abuse of power battery over-power and cause irreversible conditions such as thermal runaway, redundant fault protection is implemented for power battery power during vehicle operation. That is, the power battery power protection method provided in this embodiment can also simultaneously execute a redundant fault protection strategy, such as... Figure 4 The diagram shown is a flowchart illustrating the redundancy fault protection process in the power battery power protection method provided in this application embodiment. Figure 4 The steps shown are explained below:

[0076] Step S401: Determine the overpower protection threshold that matches the allowed power information.

[0077] In some embodiments of this application, the allowable power information obtained based on the lookup table method can be obtained by linear interpolation of the actual temperature and actual state of charge of the power battery to obtain the real-time available power of the power battery during vehicle operation.

[0078] In some embodiments of this application, the overpower protection threshold is a protection threshold preset during operation by the battery management system of the power battery.

[0079] In some embodiments of this application, the overpower protection threshold can be calculated and calibrated in various ways based on the vehicle's power economy. In some feasible implementations, the final overpower protection threshold is obtained by multiplying the allowable power information obtained from a real-time lookup table by a protection factor and adding a fixed power value. For example, the overpower protection threshold can be calculated as follows:

[0080] Overpower protection threshold = protection factor × real-time lookup value + 2kWh; for example, the protection factor can be 1.05-1.2.

[0081] Step S402: Control the power battery to perform a recharge operation or a discharge operation according to the overpower protection threshold.

[0082] In some embodiments of this application, the overpower protection threshold may include an overpower protection threshold in recharge mode and an overpower protection threshold in discharge mode. In recharge mode, when the battery power exceeds the overpower protection threshold for a certain period of time, a fault warning message is issued through the battery management system; in discharge mode, when the battery power exceeds the overpower protection threshold for a certain period of time, a fault warning message is issued through the battery management system. In some feasible implementations, the duration for which the battery power exceeds the overpower protection threshold may be 3-5 seconds.

[0083] In some embodiments of this application, redundant fault protection can be set as multi-level overpower protection thresholds. In some feasible implementations, the overpower protection thresholds include a first-level overpower protection threshold, a second-level overpower protection threshold, and a third-level overpower protection threshold. Specifically, the first-level overpower protection threshold can be calculated as: fault threshold >= 1.05 × real-time lookup table value + 2kWh), with a duration of 3s; the second-level overpower protection threshold can be calculated as: fault threshold >= 1.1 × real-time lookup table value + 2kWh), with a duration of 3s; and the third-level overpower protection threshold can be calculated as: fault threshold >= 1.2 × real-time lookup table value + 2kWh), with a duration of 3s.

[0084] This can further prevent the abuse of power battery cells, avoid irreversible conditions such as thermal runaway, and ensure the performance of the entire vehicle.

[0085] In this embodiment, considering the potential delay in the frequency response of hardware data updates during vehicle operation, which may cause the allowable power information obtained from the lookup table to be unreliable and not entirely timely, the single-cell voltage of the power battery is estimated for protection. That is, the power battery power protection method provided in this embodiment can also simultaneously perform single-cell voltage estimation protection, specifically protecting the following (not shown in the figure):

[0086] Based on the allowable power information and considering the influence of individual cell voltage factors, a target individual cell voltage protection value matching the allowable power information is determined; and the power battery is controlled to perform recharge or discharge operations according to the target individual cell voltage protection value.

[0087] In this embodiment of the application, determining the target cell voltage protection value that matches the allowable power information may include: determining the target cell voltage protection value under the recharge mode that matches the allowable power information; determining the target cell voltage protection value under the discharge mode that matches the allowable power information; such as Figure 5 , Figure 6The diagrams shown are schematic flowcharts illustrating the determination of the target cell voltage protection value in recharge mode and the determination of the target cell voltage protection value in discharge mode in the power battery power protection method provided in this application embodiment. Figure 5 , Figure 6 The steps shown are explained below:

[0088] Determining the target cell voltage protection value under the recharge mode that matches the allowed power information includes:

[0089] Step S511: Look up the first DC internal resistance of the power battery under the maximum charge and highest temperature conditions and the second DC internal resistance of the power battery under the maximum charge and lowest temperature conditions through the charge-DC internal resistance table, and compare the smaller of the two to obtain the DC internal resistance in the recharge mode.

[0090] Step S512: Calculate the first polarization voltage under different real-time pulse currents in recharge mode;

[0091] Step S513: Summing the first polarization voltage with the open-circuit voltage in the recharge mode yields the target cell voltage protection value in the recharge mode.

[0092] The determination of the target cell voltage protection value under the discharge mode that matches the allowable power information includes:

[0093] Step S521: Look up the third DC internal resistance of the power battery under the maximum charge and highest temperature conditions and the fourth DC internal resistance of the power battery under the maximum charge and lowest temperature conditions through the charge-DC internal resistance table, and compare the smaller of the two to obtain the DC internal resistance in the discharge mode.

[0094] Step S522: Calculate the second polarization voltage under different real-time pulse currents in different discharge modes;

[0095] Step S523: Summing the second polarization voltage with the open-circuit voltage in the discharge mode yields the target cell voltage protection value in the discharge mode;

[0096] The open-circuit voltage in the recharge mode and the open-circuit voltage in the discharge mode are obtained by looking up a table based on the charge-open-circuit voltage curve.

[0097] In this way, considering the safety of the battery system, the voltage of the individual power battery cells is estimated and protected, avoiding overcharging and over-discharging faults of the battery system caused by excessive use of the load side.

[0098] In some embodiments of this application, the power of the power battery can be limited by determining the cell voltage under different temperature conditions and based on preset cell voltage thresholds under different temperature conditions. These different temperature conditions can include normal temperature and low temperature conditions. Normal temperature conditions can be an environment with a temperature of (25±2)℃, and low temperature conditions can be an environment with a temperature between -5℃ and 0℃. In some embodiments of this application, the power of the power battery can be limited by adopting a tiered limitation method.

[0099] In some feasible implementations, the tiered restriction method under normal temperature conditions may include:

[0100] When the single-unit voltage is <= 2.9V for 0.5s, the power drops to 70% of the table value;

[0101] When the single-unit voltage is <= 2.85V for 0.5s, the power drops to 40% (refer to the table value).

[0102] If the single-unit voltage is <= 2.8V for 0.5s, the power drops to 30% (refer to the table value).

[0103] If the single-unit voltage is <= 2.7V for 0.5s, the power drops to 10% (refer to the table value).

[0104] If the individual cell voltage is >= 3.3V for 1 second, the power will return to the original value from the lookup table.

[0105] In some feasible implementations, the tiered restriction method under low-temperature conditions may include:

[0106] When the single-unit voltage is <= 2.8V for 0.5s, the power drops to 70% of the table value;

[0107] When the single-unit voltage is <= 2.7V for 0.5s, the power drops to 40% (refer to the table value).

[0108] If the single-unit voltage is <= 2.6V for 0.5s, the power drops to 30% (refer to the table value).

[0109] If the individual cell voltage is <= 2.55V for 0.5s, the power drops to 10% (refer to the table value).

[0110] If the individual cell voltage is >= 3.2V for 1 second, the power will return to the original value from the lookup table.

[0111] The threshold values ​​and durations of individual cell voltages at each level can be calibrated according to different vehicle models and operating conditions. To ensure smooth vehicle power delivery, the power decrease and recovery can be gradual, decreasing or increasing at a uniform rate. For example, the power decrease rate can be a 10% lookup value, and the power recovery rate can be a 5% lookup value. In this way, through graded self-protection of individual cell voltages, system abuse under fault conditions is avoided, battery system safety is protected, and battery system life is extended.

[0112] Based on the foregoing embodiments, this application provides a power battery power protection device, which includes an information acquisition unit and a charge / discharge power switching unit, such as... Figure 7 The diagram shown is a structural schematic of the power battery power protection device provided in an embodiment of this application, wherein:

[0113] The information acquisition unit 701 is used to acquire the allowable power information of the power battery under actual state of charge; the allowable power information includes at least the peak charge and discharge power and the continuous charge and discharge power;

[0114] The charging and discharging power switching unit 702 is used to time the running time of the actual power when the actual power of the power battery exceeds the peak charging and discharging power, and after the running time reaches a first preset time, to switch the available effective power to a preset power value; wherein, the preset power value is greater than the continuous charging and discharging power.

[0115] In other embodiments of this application, the charge / discharge power switching unit 702 is also configured to perform the following:

[0116] The preset power value includes at least a first gradient power value and a second gradient power value, wherein the first gradient power value is greater than the second gradient power value;

[0117] After the running time reaches the first preset time, the available effective power of the power battery is switched to the first gradient power value;

[0118] After the actual power of the power battery exceeds the first preset power value and operates for a second preset time, the available effective power of the power battery is switched to the second gradient power value.

[0119] In other embodiments of this application, the charge / discharge power switching unit 702 is also configured to perform the following:

[0120] When the actual power of the power battery is lower than the continuous charge and discharge power, the running time of the actual power is timed, and after a second preset time is reached, the available effective power of the power battery is restored to the peak charge and discharge power.

[0121] In other embodiments of this application, the power battery power protection device is also used to perform the following:

[0122] Determine the overpower protection threshold that matches the allowed power information;

[0123] According to the overpower protection threshold, the power battery is controlled to perform recharge or discharge operations.

[0124] In other embodiments of this application, the power battery power protection device is also used to perform the following:

[0125] Based on the allowable power information and considering the influence of individual cell voltage factors, a target individual cell voltage protection value matching the allowable power information is determined; and the power battery is controlled to perform recharge or discharge operations according to the target individual cell voltage protection value.

[0126] In other embodiments of this application, the power battery power protection device is also used to perform the following: determine a target single-cell voltage protection value under a recharge mode that matches the allowed power information;

[0127] Determining the target cell voltage protection value under the recharge mode that matches the allowed power information includes:

[0128] The first DC internal resistance of the power battery under the maximum charge and highest temperature is obtained by looking up the table of charge and DC internal resistance, and the second DC internal resistance of the power battery under the maximum charge and lowest temperature. The smaller of the two is then used as the DC internal resistance in the recharge mode.

[0129] Calculate the first polarization voltage under different real-time pulse currents in recharge mode;

[0130] The target cell voltage protection value under the recharge mode is obtained by summing the first polarization voltage with the open circuit voltage under the recharge mode.

[0131] In other embodiments of this application, the power battery power protection device is also used to perform the following: determine a target cell voltage protection value under a discharge mode that matches the allowed power information;

[0132] The determination of the target cell voltage protection value under the discharge mode that matches the allowable power information includes:

[0133] The third DC internal resistance of the power battery under the maximum charge and highest temperature is obtained by looking up the table of charge and DC internal resistance, and the fourth DC internal resistance of the power battery under the maximum charge and lowest temperature. The smaller of the two is then used as the DC internal resistance in the discharge mode.

[0134] Calculate the second polarization voltage under different real-time pulse currents in different discharge modes;

[0135] The target cell voltage protection value under the discharge mode is obtained by summing the second polarization voltage with the open circuit voltage under the discharge mode.

[0136] The open-circuit voltage in the recharge mode and the open-circuit voltage in the discharge mode are obtained by looking up a table based on the charge-open-circuit voltage curve.

[0137] In other embodiments of this application, the power battery power protection device is also used to perform the following:

[0138] The voltage of a single cell under different temperature conditions is determined, and the power of the power battery is limited by a tiered restriction method based on the preset voltage threshold of the single cell under different temperature conditions.

[0139] Based on the foregoing embodiments, embodiments of this application provide a vehicle, including a powertrain system and a controller, such as... Figure 8 The diagram shown is a structural schematic of the vehicle provided in an embodiment of this application, wherein:

[0140] The power system 801 includes at least a power battery;

[0141] The controller 802 is used to perform Figure 1-6 The corresponding embodiments provide the steps of the power battery power protection method.

[0142] The descriptions of the power battery power protection device and vehicle embodiments above are similar to those of the method embodiments described above, and have similar technical descriptions and beneficial effects. Due to space limitations, please refer to the descriptions of the method embodiments above, and therefore will not be repeated here. For technical details not disclosed in the battery power protection device and vehicle embodiments provided in this application, please refer to the descriptions of the method embodiments of this application for understanding.

[0143] It should be understood that the phrase "an embodiment" or "one embodiment" throughout the specification means that a specific feature, structure, or characteristic related to the embodiment is included in at least one embodiment of the embodiments of this application. Therefore, "in one embodiment" or "one embodiment" appearing throughout the specification does not necessarily refer to the same embodiment. Furthermore, these specific features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. It should be understood that in the various embodiments of the embodiments of this application, the sequence number of the above-described processes does not imply the order of execution; the execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application. The sequence numbers of the above-described embodiments are merely for descriptive purposes and do not represent the superiority or inferiority of the embodiments. It should be noted that in this application, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0144] In the several embodiments provided in this application, it should be understood that the disclosed devices and methods can be implemented in other ways. The device embodiments described above are merely illustrative. For example, the division of units is only a logical functional division, and in actual implementation, there may be other division methods, such as: multiple units or components can be combined, or integrated into another system, or some features can be ignored or not executed. In addition, the coupling, direct coupling, or communication connection between the various components shown or discussed can be through some interfaces, and the indirect coupling or communication connection between devices or units can be electrical, mechanical, or other forms.

[0145] The units described above as separate components may or may not be physically separate. The components shown as units may or may not be physical units. They may be located in one place or distributed across multiple network units. Some or all of the units may be selected to achieve the purpose of this embodiment according to actual needs.

[0146] If the integrated units described above in this application's embodiments are implemented as software functional modules and sold or used as independent products, they can also be stored in a computer-readable storage medium. Based on this understanding, the technical solutions of this application's embodiments, essentially or in other words, the parts that contribute to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the methods described in the various embodiments of this application's embodiments. The above descriptions are merely specific implementations of the embodiments of this application, but the protection scope of the embodiments of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the embodiments of this application should be included within the protection scope of the embodiments of this application. Therefore, the protection scope of the embodiments of this application should be determined by the protection scope of the claims.

Claims

1. A power battery power protection method, characterized in that, The method includes: Obtain the allowable power information of the power battery under actual state of charge; the allowable power information includes at least the peak charge / discharge power and the continuous charge / discharge power; When the actual power of the power battery exceeds the peak charge / discharge power, the operating time of the actual power is timed. After the running time reaches a first preset time, the available effective power of the power battery is switched to a preset power value; wherein, the preset power value is greater than the continuous charging and discharging power; The method further includes: determining a target single-cell voltage protection value that matches the allowable power information, considering the influence of single-cell voltage factors; and controlling the power battery to perform recharge or discharge operations according to the target single-cell voltage protection value. The target cell voltage protection value that matches the allowed power information includes the target cell voltage protection value in recharge mode; determining the target cell voltage protection value that matches the allowed power information includes: The first DC internal resistance of the power battery under the maximum charge and highest temperature is obtained by looking up the table of charge and DC internal resistance, and the second DC internal resistance of the power battery under the maximum charge and lowest temperature. The smaller of the two is then used as the DC internal resistance in the recharge mode. Calculate the first polarization voltage under different real-time pulse currents in recharge mode; The target cell voltage protection value under the recharge mode is obtained by summing the first polarization voltage with the open circuit voltage under the recharge mode.

2. The power battery power protection method according to claim 1, characterized in that, The preset power value includes at least a first gradient power value and a second gradient power value; wherein the first gradient power value is greater than the second gradient power value; The step of switching the available effective power of the power battery to a preset power value after the running time reaches a first preset time includes: After the running time reaches the first sub-preset time, the available effective power of the power battery is switched to the first gradient power value; the first sub-preset time is less than the first preset time; When the actual power of the power battery exceeds the first gradient power value and the operation reaches a second sub-preset time, it is determined that the operation time has reached the first preset time. After the running time reaches the first preset time, the available effective power of the power battery is switched to the second gradient power value.

3. The power battery power protection method according to claim 1 or 2, characterized in that, The method further includes: When the actual power of the power battery is lower than the continuous charge and discharge power, the running time of the actual power is timed, and after a second preset time is reached, the available effective power of the power battery is restored to the peak charge and discharge power.

4. The power battery power protection method according to claim 1 or 2, characterized in that, The method further includes: Determine the overpower protection threshold that matches the allowed power information; According to the overpower protection threshold, the power battery is controlled to perform recharge or discharge operations.

5. The power battery power protection method according to claim 1 or 2, characterized in that, The target cell voltage protection value that allows the power information to match the target cell voltage protection value also includes the target cell voltage protection value under discharge mode. Determining the target cell voltage protection value that matches the allowable power information includes: The third DC internal resistance of the power battery under the maximum charge and highest temperature is obtained by looking up the table of charge and DC internal resistance, and the fourth DC internal resistance of the power battery under the maximum charge and lowest temperature. The smaller of the two is then used as the DC internal resistance in the discharge mode. Calculate the second polarization voltage under different real-time pulse currents in different discharge modes; The target cell voltage protection value under the discharge mode is obtained by summing the second polarization voltage with the open circuit voltage under the discharge mode. The open-circuit voltage in the recharge mode and the open-circuit voltage in the discharge mode are obtained by looking up a table based on the charge-open-circuit voltage curve.

6. The power battery power protection method according to claim 1 or 2, characterized in that, The method further includes: The voltage of a single cell under different temperature conditions is determined, and the power of the power battery is limited by a tiered restriction method based on the preset voltage threshold of the single cell under different temperature conditions.

7. A power battery power protection device, characterized in that, include: The information acquisition unit is used to acquire the allowable power information of the power battery under actual state of charge. The permitted power information includes at least the peak charge / discharge power and the continuous charge / discharge power; A charge / discharge power switching unit is used to time the running time of the actual power when the actual power of the power battery exceeds the peak charge / discharge power, and after the running time reaches a first preset time, to switch the available effective power of the power battery to a preset power value; wherein the preset power value is greater than the continuous charge / discharge power; The power battery power protection device is also used to: determine a target single-cell voltage protection value that matches the allowable power information based on the allowable power information and considering the influence of single-cell voltage factors; and control the power battery to perform recharge or discharge operations according to the target single-cell voltage protection value. The target cell voltage protection value that matches the allowable power information includes the target cell voltage protection value in recharge mode; determining the target cell voltage protection value that matches the allowable power information includes: looking up the first DC internal resistance of the power battery under the maximum charge and highest temperature conditions and the second DC internal resistance of the power battery under the maximum charge and lowest temperature conditions through a charge-DC internal resistance table, comparing the smaller of the two and taking it as the DC internal resistance in recharge mode; calculating the first polarization voltage under different real-time pulse current conditions in recharge mode; and summing the first polarization voltage with the open circuit voltage in recharge mode to obtain the target cell voltage protection value in recharge mode.

8. A vehicle, characterized in that, Including the power system and controller; The power system includes at least a power battery; The controller is used to execute the power protection method for the vehicle's power battery as described in any one of claims 1-6.

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