A control method, device and controller for a battery management system

Abstract

The present invention discloses a control method, device, and controller for a battery management system. When the thermal management system fails, the method determines the current battery usage scenario and obtains the actual battery temperature and battery charge of the power battery. If the battery usage scenario is charging, the method controls the actual charging current of the power battery based on the actual battery temperature and battery charge, keeping the power battery within a first preset operating temperature range. If the battery usage scenario is driving, the method controls the discharge current and feedback current of the power battery based on the actual battery temperature and battery charge, keeping the power battery within a second preset operating temperature range. This method provides customers with a certain amount of room for use and disposal during periods when the vehicle's thermal management fails, significantly reduces the risk of battery misuse during periods without thermal management capabilities, and minimizes losses.

Description

Technical Field

[0001] The present invention relates to the technical field of new energy vehicles, and in particular to a control method, device and controller for a battery management system. Background Art

[0002] The power batteries in new energy vehicles have an appropriate operating temperature. The power battery thermal management system will activate when the temperature is too high or too low to adjust the ambient temperature of the power battery and keep the power battery at the appropriate operating temperature.

[0003] However, if thermal management fails and is not repaired in time, the power battery will lose its ability to regulate temperature. At this time, if the ambient temperature of the power battery exceeds the appropriate operating temperature range, it will easily cause the power battery capacity to decay rapidly and even increase safety risks. Summary of the Invention

[0004] In view of the above problems, the present invention proposes a control method, device and controller for a battery management system, which can provide customers with a certain amount of usage and disposal space when thermal management fails but is not repaired in time, thereby greatly reducing the risk of battery abuse during the period when there is no thermal management capability.

[0005] According to a first aspect of the present invention, a control method for a battery management system is provided, comprising:

[0006] When the thermal management system fails, determine the current battery usage scenario and obtain the actual battery temperature and battery power of the power battery;

[0007] If the battery usage scenario is a charging scenario, controlling the actual charging current of the power battery according to the actual battery temperature and the battery power so that the power battery is within a first preset operating temperature range;

[0008] If the battery usage scenario is a driving scenario, the discharge current and the feedback current of the power battery are controlled according to the actual battery temperature and the battery power, so that the power battery is within a second preset operating temperature range.

[0009] Optionally, controlling the actual charging current of the power battery according to the actual battery temperature and the battery power includes:

[0010] Obtain the initial charge of the power battery when charging begins and the target charging current at each charging stage;

[0011] Determining a charging coefficient of a heat transfer parameter of the power battery at each charging stage according to the initial power quantity;

[0012] predicting a battery charging temperature of the power battery according to the battery power, the actual battery temperature, the target charging current of each charging stage, a heat transfer parameter of the power battery, and a charging coefficient of the heat transfer parameter in each charging stage;

[0013] If the battery charging temperature exceeds a first preset operating temperature range, the actual charging current of the power battery is reduced.

[0014] Optionally, if the battery charging temperature exceeds a first preset operating temperature range, reducing the actual charging current of the power battery includes:

[0015] If the battery charging temperature exceeds a first preset operating temperature range, the actual charging current of the power battery in each charging stage is reduced according to a first ratio.

[0016] Optionally, if the battery charging temperature exceeds a first preset operating temperature range, reducing the actual charging current of the power battery includes:

[0017] If the battery charging temperature exceeds a first preset operating temperature range, the actual charging current in the current charging stage is reduced, and the current reduction step includes:

[0018] taking the current charging stage as the target stage, and reducing the actual charging current of the target stage according to a second ratio in the target stage to obtain a reduced actual charging current;

[0019] re-predicting a battery charging temperature of the power battery based on the reduced actual charging current, the battery power, the actual battery temperature, a heat transfer parameter of the power battery, and a charging coefficient of the heat transfer parameter in each charging stage;

[0020] If the re-predicted battery charging temperature of the power battery exceeds the first preset operating temperature range, the next adjacent charging stage is used as the target stage, and the process returns to the step of reducing the actual charging current of the target stage according to the second ratio.

[0021] Optionally, reducing the actual charging current in the target stage according to a second ratio includes:

[0022] If the reduced actual charging current is greater than the current threshold, re-predicting the battery charging temperature of the power battery based on the reduced actual charging current, the battery power, the actual battery temperature, the heat transfer parameter of the power battery, and the charging coefficient of the heat transfer parameter in each charging stage;

[0023] If the reduced actual charging current is less than or equal to the current threshold, the current threshold is updated to the reduced actual charging current to obtain an updated actual charging current, and the battery charging temperature of the power battery is re-predicted based on the updated actual charging current, the battery power, the actual battery temperature, the heat transfer parameters of the power battery, and the charging coefficient of the heat transfer parameters in each charging stage.

[0024] Optionally, controlling the discharge current and the feedback current of the power battery according to the actual battery temperature and the battery power includes:

[0025] determining a discharge coefficient of a heat transfer parameter of the power battery according to the battery power;

[0026] predicting a battery discharge temperature of the power battery according to the actual battery temperature, a heat transfer parameter of the power battery, a discharge coefficient of the heat transfer parameter, and the discharge current;

[0027] If the battery discharge temperature exceeds a second preset operating temperature range, the discharge current and the feedback current of the power battery are reduced.

[0028] Optionally, reducing the discharge current and feedback current of the power battery includes:

[0029] When the actual battery temperature is greater than or equal to a first threshold and less than a second threshold, reducing the discharge current and the feedback current according to a third ratio;

[0030] When the actual battery temperature is greater than or equal to a second threshold and less than a third threshold, reducing the discharge current and the feedback current according to a fourth ratio;

[0031] When the actual battery temperature is greater than or equal to a third threshold and less than a fourth threshold, the discharge current and the feedback current are reduced according to a fifth ratio; wherein the third ratio is greater than the fourth ratio, the fourth ratio is greater than the fifth ratio, the first threshold is less than the second threshold, the second threshold is less than the third threshold, and the third threshold is less than a maximum temperature value in the second preset operating temperature range.

[0032] Optionally, determining the current battery usage scenario when the thermal management system fails includes:

[0033] Get the status of the thermal management system;

[0034] If the thermal management system is in a failed state, obtaining the vehicle's charging information and speed;

[0035] If the charging information of the vehicle is a charging state, the battery usage scenario is a charging scenario;

[0036] If the vehicle speed is greater than the target vehicle speed, the battery usage scenario is a driving scenario.

[0037] According to a second aspect of the present invention, a control device for a battery management system is provided, comprising:

[0038] The determination module is used to determine the current battery usage scenario and obtain the actual battery temperature and battery power of the power battery when the thermal management system fails.

[0039] a first control module, configured to control an actual charging current of the power battery according to the actual battery temperature and the battery power level, so that the power battery is within a first preset operating temperature range, if the battery usage scenario is a charging scenario;

[0040] The second control module is used to control the discharge current and feedback current of the power battery according to the actual battery temperature and the battery power if the battery usage scenario is a driving scenario, so that the power battery is within a second preset operating temperature range.

[0041] According to a third aspect of the present invention, a controller is provided. The controller includes a memory, a processor, and a computer program stored in the memory and executable on the processor. The processor executes the aforementioned control method for the battery management system.

[0042] The above one or more technical solutions in the embodiments of this specification have at least the following technical effects:

[0043] The embodiments of this specification provide a control method, device, and controller for a battery management system. When the thermal management system fails, the method determines the current battery usage scenario and obtains the actual battery temperature and battery charge of the power battery. If the battery usage scenario is charging, the method controls the actual charging current of the power battery based on the actual battery temperature and battery charge, keeping the power battery within a first preset operating temperature range. If the battery usage scenario is driving, the method controls the discharge current and feedback current of the power battery based on the actual battery temperature and battery charge, keeping the power battery within a second preset operating temperature range. This provides customers with a certain level of usage and disposal space during periods when the vehicle's thermal management fails, significantly reduces the risk of battery misuse during periods without thermal management capabilities, and minimizes losses.

[0044] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are specifically listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiment below. The accompanying drawings are for illustration purposes only and are not to be considered as limiting the present invention. Throughout the drawings, the same reference figures denote the same components. In the drawings:

[0046] Figure 1 A flow chart of a control method for a battery management system in an embodiment of the present invention is shown.

[0047] Figure 2 A block diagram of a control device for a battery management system in an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0048] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0049] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention as claimed, but rather merely represents selected embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort are intended to fall within the scope of protection of the present invention.

[0050] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0051] In the description of the present invention, it should also be noted that, unless otherwise expressly specified or limited, the terms "disposed," "installed," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to mechanical connections or electrical connections; they may refer to direct connections or indirect connections through an intermediate medium; and they may refer to internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0052] The embodiment of the present invention provides a control method for a battery management system, combining Figure 1 As shown in the flowchart, the control method of the battery management system includes steps 101 to 103:

[0053] Step 101: When the thermal management system fails, determine the current battery usage scenario and obtain the actual battery temperature and battery power of the power battery;

[0054] In this embodiment, the vehicle is a new energy vehicle equipped with a power battery. Power batteries should not operate too hot or too cold. In other words, power batteries have an optimal temperature range, generally between 10-30°C. However, the operating environment of a vehicle is very wide, ranging from -20 to 50°C.

[0055] Therefore, when the ambient temperature of the power battery exceeds the appropriate temperature range, the thermal management system will adjust the temperature so that the power battery can be kept within the appropriate temperature range.

[0056] However, during actual vehicle use, the thermal management system may develop problems, resulting in a loss of temperature regulation. However, at this point, the owner may not have had time to send the vehicle in for repair. If the power battery is still used according to the previous charge and discharge map when the thermal management system fails, the power battery's temperature may exceed the appropriate temperature range, which may cause abuse of the power battery. This is because when the temperature is too low, the power battery is more susceptible to lithium deposition during cycling, while when the temperature is too high, the stability of the positive electrode structure decreases. Improper power battery temperature can cause rapid battery capacity decay and even increase safety risks.

[0057] In order to avoid the above situation, this embodiment will first determine the current battery usage scenario when the thermal management system fails.

[0058] Because different battery usage scenarios require different control strategies, in this embodiment, battery usage scenarios generally include two types, namely, charging scenarios and driving scenarios.

[0059] In one embodiment, the step of determining the current battery usage scenario may include:

[0060] Get the status of the thermal management system;

[0061] If the state of the thermal management system is a failure state, obtaining the charging information and vehicle speed of the vehicle;

[0062] If the charging information of the vehicle is a charging state, the battery usage scenario is a charging scenario;

[0063] If the vehicle speed is greater than the target vehicle speed, the battery usage scenario is a driving scenario.

[0064] The thermal management system status indicates whether the system is operating normally. It can be in a normal or faulty state. If the thermal management system is in a normal state, it can normally regulate the power battery temperature. If the thermal management system is in a faulty state, it has lost the ability to regulate the power battery temperature.

[0065] When the thermal management system is in a failed state, the vehicle's charging information and speed are obtained. The purpose of obtaining the vehicle's charging information and speed is to determine the vehicle's current battery usage scenario. If the charging information indicates that the power battery is charging, the vehicle is charging, meaning the battery usage scenario is charging. If the speed is greater than the target speed, the vehicle is driving, meaning the power battery is discharging, and the battery usage scenario is driving. The target speed is a smaller value to determine whether the vehicle is driving.

[0066] The actual battery temperature of the power battery refers to the current temperature of the power battery. The battery power refers to the current real-time power of the power battery.

[0067] Step 102: If the battery usage scenario is a charging scenario, controlling the actual charging current of the power battery according to the actual battery temperature and the battery power, so that the power battery is within a first preset operating temperature range;

[0068] In this embodiment, since the power battery accumulates heat during charging, it is necessary to predict the battery charging temperature at different charging stages. If the battery charging temperature exceeds a first preset operating temperature range, appropriate control is required, generally by reducing the charging current of the power battery to reduce heat accumulation.

[0069] Step 103: If the battery usage scenario is a driving scenario, the discharge current and the feedback current of the power battery are controlled according to the actual battery temperature and the battery power, so that the power battery is in a second preset operating temperature range.

[0070] In this embodiment, since the power battery also generates heat during discharge, it is necessary to predict the battery discharge temperature during discharge. If the battery discharge temperature exceeds the second preset operating temperature range, appropriate control is required, generally reducing the power battery's discharge current and regenerative current to reduce heat accumulation. Regenerative current refers to the charging current during energy recovery.

[0071] It should be noted that the first preset operating temperature range refers to the appropriate operating temperature range for the power battery in a charging scenario, and the second preset operating temperature range refers to the appropriate operating temperature range for the power battery in a discharging scenario. The first preset operating temperature range and the second preset operating temperature range can be the same. Even if the first preset operating temperature range and the second preset operating temperature range are different, the temperature ranges covered by the two are largely overlapping.

[0072] It is not difficult to see that when the thermal management system fails, by distinguishing the usage scenarios of different power batteries and thus controlling the charging current or discharging current and feedback current in a targeted manner, a certain amount of usage and disposal space can be gained for customers, and the risk of battery abuse during the period without thermal management capability can be greatly reduced.

[0073] In one embodiment, the step of controlling the actual charging current of the power battery according to the actual battery temperature and the battery power may include:

[0074] Obtain the initial charge of the power battery when charging begins and the target charging current at each charging stage;

[0075] Determining a charging coefficient of a heat transfer parameter of the power battery at each charging stage according to the initial power quantity;

[0076] predicting a battery charging temperature of the power battery according to the battery power, the actual battery temperature, the target charging current of each charging stage, a heat transfer parameter of the power battery, and a charging coefficient of the heat transfer parameter in each charging stage;

[0077] If the battery charging temperature exceeds a first preset operating temperature range, the actual charging current of the power battery is reduced.

[0078] The starting charge refers to the battery charge at the start of the current charge. The target charging current for each charging stage can be determined based on a pre-set charging map in the prior art. In the event of a thermal management failure, the temperature rise of the power battery is primarily related to the charging current and heat transfer parameters. In this embodiment, the heat transfer parameters may include the specific heat capacity at different locations on the power battery.

[0079] It should be noted that when charging, the power battery has different charging stages, and each charging stage has a corresponding target charging current. At the same time, the greater the actual charging current, the more heat is generated. It should be noted that in actual experiments, we found that even in the same charging stage, if the starting charge is different, the heat generated in the charging stage will also be different. For example, when the vehicle starts charging from 25%, it is charged to 33%, and the corresponding charging current is 100A. The temperature rise rate at this time is A; when the vehicle starts charging from 30%, it is charged to 33%, and the corresponding charging current is 100A. The temperature rise rate at this time is B; and B is slightly greater than A.

[0080] It's easy to understand that different starting charges, even with the same charging current during the same charging phase, will result in slightly different corresponding temperature rise rates. Based on this, this embodiment uses a large number of temperature rise rate calibration experiments to calibrate the charging coefficients of the heat transfer parameters. This allows for a fitting relationship between temperature rise, charging current, and heat transfer parameters.

[0081] It is important to note that the charging coefficient of the heat transfer parameter is different for each charging stage, and the corresponding charging coefficient will also be different if the starting charge is different in the same charging stage. Therefore, the starting charge is required to determine the charging coefficient of the heat transfer parameter of the power battery in each charging stage.

[0082] The target charging current for each subsequent charging stage can then be determined based on the battery charge level. The temperature rise for each charging stage can then be calculated by combining the heat transfer parameter, the charging coefficient of the heat transfer parameter for each charging stage, and the target charging current for each charging stage. Based on the temperature rise for each charging stage and the actual battery temperature, the corresponding battery charging temperature for each subsequent charging stage can be predicted.

[0083] For the battery charging temperatures corresponding to the subsequent charging stages, if the battery charging temperature in any charging stage exceeds the first preset operating temperature range, the actual charging current of the power battery is reduced. Exceeding the first preset operating temperature range here mainly refers to being greater than the maximum value of the first preset operating temperature range.

[0084] In this embodiment, there are multiple ways to reduce the actual charging current of the power battery. This can be done by reducing the charging current at all charging stages, reducing the charging current in stages, or combining the two. Specifically:

[0085] In one embodiment, if the battery charging temperature exceeds a first preset operating temperature range, the actual charging current of the power battery in each charging stage is reduced according to a first ratio. For example, the first ratio may be 90%. If the predicted battery charging temperature still exceeds the first preset operating temperature range, the ratio is further reduced, such as to 80%, until the predicted battery charging temperature does not exceed the first preset operating temperature range.

[0086] In another embodiment, if the battery charging temperature exceeds a first preset operating temperature range, the actual charging current in the current charging stage is reduced. The current reduction step may include:

[0087] taking the current charging stage as the target stage, and reducing the actual charging current of the target stage according to a second ratio in the target stage to obtain a reduced actual charging current;

[0088] re-predicting a battery charging temperature of the power battery based on the reduced actual charging current, the battery power, the actual battery temperature, a heat transfer parameter of the power battery, and a charging coefficient of the heat transfer parameter in each charging stage;

[0089] If the re-predicted battery charging temperature of the power battery exceeds the first preset operating temperature range, the next adjacent charging stage is used as the target stage, and the process returns to the step of reducing the actual charging current of the target stage according to the second ratio.

[0090] As will be readily understood, when the battery charging temperature exceeds the first preset operating temperature range, current reduction can be implemented in stages. First, the actual charging current in the current charging stage is reduced according to the second ratio, and then the battery charging temperature for each subsequent charging stage is predicted. If the battery charging temperature exceeds the first preset operating temperature range, the second ratio is reduced, the actual charging current in the current charging stage is further reduced, and the battery charging temperature for each subsequent charging stage is again predicted. If the battery charging temperature is within the first preset operating temperature range, charging is continued according to the actual charging current after the current reduction. If the battery charging temperature still exceeds the first preset operating temperature range, current reduction continues.

[0091] However, it is necessary to set a minimum flow reduction ratio (for example, 50%) or a current threshold of the minimum charging current (for example, the minimum charging current of the charging pile is 50A). If the actual charging current after the reduction is greater than the current threshold or the second ratio after the reduction is greater than the minimum flow reduction ratio, the battery charging temperature of the power battery can be re-predicted based on the actual charging current after the reduction, the battery power, the actual battery temperature, the heat transfer parameters of the power battery, and the charging coefficient of the heat transfer parameters of each charging stage; if the actual charging current after the reduction is less than or equal to the current threshold or the second ratio after the reduction is less than or equal to the minimum flow reduction ratio, the current threshold is updated to the actual charging current after the reduction to obtain the updated actual charging current, and the battery charging temperature of the power battery is re-predicted based on the updated actual charging current, the battery power, the actual battery temperature, the heat transfer parameters of the power battery, and the charging coefficient of the heat transfer parameters of each charging stage. That is to say, after the actual charging current after reduction is less than or equal to the current threshold or the second ratio after reduction is less than or equal to the minimum current reduction ratio, charging is performed with the current threshold as the actual charging current of the current charging stage, and then the next adjacent charging stage is used as the target stage, and the current reduction processing steps are continued until the predicted battery charging temperature is within the first preset operating temperature range.

[0092] The use scenarios of power batteries include not only charging scenarios, but also driving scenarios. In driving scenarios, the power battery is discharging most of the time, but when braking, the vehicle will recover energy, at which time the power battery will be briefly charged. For power batteries, there is both discharge current and regenerative current. Therefore, in driving scenarios, the discharge current and regenerative current need to be controlled. Specific steps may include:

[0093] determining a discharge coefficient of a heat transfer parameter of the power battery according to the battery power;

[0094] predicting a battery discharge temperature of the power battery according to the actual battery temperature, a heat transfer parameter of the power battery, a discharge coefficient of the heat transfer parameter, and the discharge current;

[0095] If the battery discharge temperature exceeds a second preset operating temperature range, the discharge current and the feedback current of the power battery are reduced.

[0096] It should be noted that during the initial discharge of a power battery, heat accumulation is greater, and then gradually levels off. Different battery capacities correspond to different discharge coefficients of heat transfer parameters.

[0097] In the prior art, the temperature rise of power batteries is primarily related to discharge current and heat transfer parameters. In the event of thermal management failure, this embodiment uses extensive discharge calibration experiments to correct the discharge coefficient of the heat transfer parameters. This allows for a fitting relationship between temperature rise, discharge current, and heat transfer parameters.

[0098] Then, based on the power battery's heat transfer parameters, the discharge coefficient of the heat transfer parameters, and the discharge current, combined with the actual battery temperature of the power battery, the battery discharge temperature during the process of the power battery running to zero power is predicted. If the battery discharge temperature exceeds the second preset operating temperature range during the predicted discharge process, the discharge current and feedback current of the power battery are reduced. Specific current reduction steps may include:

[0099] When the actual battery temperature is greater than or equal to a first threshold and less than a second threshold, reducing the discharge current and the feedback current according to a third ratio;

[0100] When the actual battery temperature is greater than or equal to a second threshold and less than a third threshold, reducing the discharge current and the feedback current according to a fourth ratio;

[0101] When the actual battery temperature is greater than or equal to a third threshold and less than a fourth threshold, the discharge current and the feedback current are reduced according to a fifth ratio; wherein the third ratio is greater than the fourth ratio, the fourth ratio is greater than the fifth ratio, the first threshold is less than the second threshold, the second threshold is less than the third threshold, and the third threshold is less than a maximum temperature value in the second preset operating temperature range.

[0102] This embodiment sets three thresholds: a first threshold, a second threshold, and a third threshold. These thresholds divide the battery temperature rise into three distinct stages. The discharge current and feedback current are then reduced according to different reduction ratios. The closer the actual battery temperature is to the second preset operating temperature range, the smaller the reduction ratio and the greater the current reduction.

[0103] For example, the first threshold T1 < the second threshold T2 < the third threshold T3, T3 is 60 degrees, T2 is 55 degrees, and T1 is 48 degrees. The third ratio is 80%, the fourth ratio is 60%, and the fifth ratio is 40%.

[0104] If the actual battery temperature is 50 degrees and the current discharge current is 50A, the discharge current is reduced by 80%, and the obtained discharge current after the reduction is 40A.

[0105] The degree of power discounting is related to the temperature threshold settings. Higher temperature thresholds result in greater discounts. Different vehicle models have different usage scenarios. A higher temperature threshold is recommended for those who prioritize the user's driving experience, while a lower threshold is recommended for those who prioritize the vehicle's lifespan.

[0106] In addition, to more broadly meet the needs of different vehicle usage scenarios, other influencing factors can be combined to limit the reduction ratio in charging and driving scenarios. Because users focus on different aspects, the weight of each influencing factor can be set by the user. The influencing factors in this embodiment include the user's driving experience, service life, the user's concern about charging time, and the user's sensitivity to electricity prices. The aforementioned reduction ratios are then adjusted based on the weights of each influencing factor entered by the user.

[0107] In summary, the embodiments of this specification provide a control method for a battery management system. When the thermal management system fails, the method determines the current battery usage scenario and obtains the actual battery temperature and battery charge of the power battery. If the battery usage scenario is charging, the method controls the actual charging current of the power battery based on the actual battery temperature and battery charge, keeping the power battery within a first preset operating temperature range. If the battery usage scenario is driving, the method controls the discharge current and feedback current of the power battery based on the actual battery temperature and battery charge, keeping the power battery within a second preset operating temperature range. This method provides customers with a certain level of usage and disposal space during periods when the vehicle's thermal management fails, significantly reduces the risk of battery misuse during periods without thermal management capabilities, and minimizes losses.

[0108] Based on the same inventive concept, combined Figure 2 As shown, an embodiment of the present invention further provides a control device for a battery management system, comprising:

[0109] The determination module is used to determine the current battery usage scenario and obtain the actual battery temperature and battery power of the power battery when the thermal management system fails.

[0110] a first control module, configured to control an actual charging current of the power battery according to the actual battery temperature and the battery power level, so that the power battery is within a first preset operating temperature range, if the battery usage scenario is a charging scenario;

[0111] The second control module is used to control the discharge current and feedback current of the power battery according to the actual battery temperature and the battery power if the battery usage scenario is a driving scenario, so that the power battery is within a second preset operating temperature range.

[0112] Optionally, the first control module is further configured to:

[0113] Obtain the initial charge of the power battery when charging begins and the target charging current at each charging stage;

[0114] Determining a charging coefficient of a heat transfer parameter of the power battery at each charging stage according to the initial power quantity;

[0115] predicting a battery charging temperature of the power battery according to the battery power, the actual battery temperature, the target charging current of each charging stage, a heat transfer parameter of the power battery, and a charging coefficient of the heat transfer parameter in each charging stage;

[0116] If the battery charging temperature exceeds a first preset operating temperature range, the actual charging current of the power battery is reduced.

[0117] Optionally, the first control module is further configured to:

[0118] If the battery charging temperature exceeds a first preset operating temperature range, the actual charging current of the power battery in each charging stage is reduced according to a first ratio.

[0119] Optionally, the first control module is further configured to:

[0120] If the battery charging temperature exceeds a first preset operating temperature range, the actual charging current in the current charging stage is reduced, and the current reduction step includes:

[0121] taking the current charging stage as the target stage, and reducing the actual charging current of the target stage according to a second ratio in the target stage to obtain a reduced actual charging current;

[0122] re-predicting a battery charging temperature of the power battery based on the reduced actual charging current, the battery power, the actual battery temperature, a heat transfer parameter of the power battery, and a charging coefficient of the heat transfer parameter in each charging stage;

[0123] If the re-predicted battery charging temperature of the power battery exceeds the first preset operating temperature range, the next adjacent charging stage is used as the target stage, and the process returns to the step of reducing the actual charging current of the target stage according to the second ratio.

[0124] Optionally, the first control module is further configured to:

[0125] If the reduced actual charging current is greater than the current threshold, re-predicting the battery charging temperature of the power battery based on the reduced actual charging current, the battery power, the actual battery temperature, the heat transfer parameter of the power battery, and the charging coefficient of the heat transfer parameter in each charging stage;

[0126] If the reduced actual charging current is less than or equal to the current threshold, the current threshold is updated to the reduced actual charging current to obtain an updated actual charging current, and the battery charging temperature of the power battery is re-predicted based on the updated actual charging current, the battery power, the actual battery temperature, the heat transfer parameters of the power battery, and the charging coefficient of the heat transfer parameters in each charging stage.

[0127] Optionally, the second control module is further configured to:

[0128] determining a discharge coefficient of a heat transfer parameter of the power battery according to the battery power;

[0129] predicting a battery discharge temperature of the power battery according to the actual battery temperature, a heat transfer parameter of the power battery, a discharge coefficient of the heat transfer parameter, and the discharge current;

[0130] If the battery discharge temperature exceeds a first preset operating temperature range, the discharge current and the feedback current of the power battery are reduced.

[0131] Optionally, the second control module is further configured to:

[0132] When the actual battery temperature is greater than or equal to a first threshold and less than a second threshold, reducing the discharge current and the feedback current according to a third ratio;

[0133] When the actual battery temperature is greater than or equal to a second threshold and less than a third threshold, reducing the discharge current and the feedback current according to a fourth ratio;

[0134] When the actual battery temperature is greater than or equal to a third threshold and less than a fourth threshold, the discharge current and the feedback current are reduced according to a fifth ratio; wherein the third ratio is greater than the fourth ratio, the fourth ratio is greater than the fifth ratio, the first threshold is less than the second threshold, the second threshold is less than the third threshold, and the third threshold is less than a maximum temperature value in the second preset operating temperature range.

[0135] Optionally, the determination module is further configured to:

[0136] Get the status of the thermal management system;

[0137] If the thermal management system is in a failed state, obtaining the vehicle's charging information and speed;

[0138] If the charging information of the vehicle is a charging state, the battery usage scenario is a charging scenario;

[0139] If the vehicle speed is greater than the target vehicle speed, the battery usage scenario is a driving scenario.

[0140] In summary, the embodiments of this specification provide a battery management system control device that, when the thermal management system fails, determines the current battery usage scenario and obtains the actual battery temperature and battery charge of the power battery. If the battery usage scenario is charging, the control device controls the actual charging current of the power battery based on the actual battery temperature and battery charge, keeping the power battery within a first preset operating temperature range. If the battery usage scenario is driving, the control device controls the discharge current and feedback current of the power battery based on the actual battery temperature and battery charge, keeping the power battery within a second preset operating temperature range. This provides customers with a certain amount of room for use and disposal during periods when the vehicle's thermal management fails, significantly reduces the risk of battery misuse during periods without thermal management capabilities, and minimizes losses.

[0141] Those skilled in the art will clearly understand that, for the convenience and brevity of description, the specific working process of the control device of the battery management system described above can refer to the corresponding process in the aforementioned method and will not be elaborated here.

[0142] Based on the same inventive concept, an embodiment of the present invention also provides a controller, which includes a control device, a memory, a processor and a communication unit of a battery management system. The memory stores machine-readable instructions executable by the processor. When the controller is running, the processor and the memory communicate through a bus, the processor executes the machine-readable instructions, and executes the control method of the battery management system.

[0143] The memory, processor, and communication unit components are electrically connected to each other directly or indirectly to enable signal transmission or interaction. For example, these components can be electrically connected to each other via one or more communication buses or signal lines. The control device of the battery management system includes at least one software function module that can be stored in the memory in the form of software or firmware. The processor is used to execute the executable module stored in the memory (e.g., the software function module or computer program included in the control device of the battery management system).

[0144] Among them, the memory can be, but is not limited to, random access memory (RAM), read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable read-only memory (EEPROM), etc.

[0145] In some embodiments, the processor is used to perform one or more functions described in this embodiment. In some embodiments, the processor may include one or more processing cores (eg, a single-core processor (S) or a multi-core processor (S)).

[0146] In this embodiment, the memory is used to store the program, and the processor is used to execute the program after receiving the execution instruction. The process definition method disclosed in any implementation of this embodiment can be applied to the processor or implemented by the processor.

[0147] The communication unit is used to establish a communication connection between the controller and other devices through the network, and to send and receive data through the network.

[0148] Those skilled in the art will clearly understand that, for the convenience and brevity of description, the specific working process of the controller described above can refer to the corresponding process in the aforementioned method, and will not be elaborated here.

[0149] According to a fourth aspect of the present invention, a vehicle is provided, comprising a vehicle body and a controller mounted within the vehicle body, the controller being configured to implement the aforementioned battery management system control method. The vehicle is a new energy vehicle and further comprises a power battery, a battery management system, and a thermal management system.

[0150] Those skilled in the art will clearly understand that, for the convenience and brevity of description, the specific working process of the vehicle controller described above can refer to the corresponding process in the aforementioned method and will not be elaborated here.

[0151] The above are merely various embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. A control method for a battery management system, characterized in that: include: When the thermal management system fails, determine the current battery usage scenario and obtain the actual battery temperature and battery power of the power battery; If the battery usage scenario is a charging scenario, controlling the actual charging current of the power battery according to the actual battery temperature and the battery power so that the power battery is within a first preset operating temperature range; If the battery usage scenario is a driving scenario, the discharge current and the feedback current of the power battery are controlled according to the actual battery temperature and the battery power, so that the power battery is within a second preset operating temperature range; The controlling the actual charging current of the power battery according to the actual battery temperature and the battery power includes: Obtain the initial charge of the power battery when charging begins and the target charging current at each charging stage; Determining a charging coefficient of a heat transfer parameter of the power battery at each charging stage according to the initial power quantity; predicting a battery charging temperature of the power battery according to the battery power, the actual battery temperature, the target charging current of each charging stage, a heat transfer parameter of the power battery, and a charging coefficient of the heat transfer parameter in each charging stage; If the battery charging temperature exceeds a first preset operating temperature range, reducing the actual charging current of the power battery; If the battery charging temperature exceeds a first preset operating temperature range, reducing the actual charging current of the power battery includes: If the battery charging temperature exceeds a first preset operating temperature range, the actual charging current in the current charging stage is reduced, and the current reduction step includes: taking the current charging stage as the target stage, and reducing the actual charging current of the target stage according to a second ratio in the target stage to obtain a reduced actual charging current; re-predicting a battery charging temperature of the power battery based on the reduced actual charging current, the battery power, the actual battery temperature, a heat transfer parameter of the power battery, and a charging coefficient of the heat transfer parameter in each charging stage; If the re-predicted battery charging temperature of the power battery exceeds the first preset operating temperature range, the next adjacent charging stage is used as the target stage, and the process returns to the step of reducing the actual charging current of the target stage according to the second ratio.

2. The method according to claim 1, characterized in that If the battery charging temperature exceeds a first preset operating temperature range, reducing the actual charging current of the power battery includes: If the battery charging temperature exceeds a first preset operating temperature range, the actual charging current of the power battery in each charging stage is reduced according to a first ratio.

3. The method according to claim 1, characterized in that The reducing the actual charging current in the target stage according to the second ratio includes: If the reduced actual charging current is greater than the current threshold, re-predicting the battery charging temperature of the power battery based on the reduced actual charging current, the battery power, the actual battery temperature, the heat transfer parameter of the power battery, and the charging coefficient of the heat transfer parameter in each charging stage; If the reduced actual charging current is less than or equal to the current threshold, the current threshold is updated to the reduced actual charging current to obtain an updated actual charging current, and the battery charging temperature of the power battery is re-predicted based on the updated actual charging current, the battery power, the actual battery temperature, the heat transfer parameters of the power battery, and the charging coefficient of the heat transfer parameters in each charging stage.

4. The method according to claim 1, wherein The controlling the discharge current and the feedback current of the power battery according to the actual battery temperature and the battery power includes: determining a discharge coefficient of a heat transfer parameter of the power battery according to the battery power; predicting a battery discharge temperature of the power battery according to the actual battery temperature, a heat transfer parameter of the power battery, a discharge coefficient of the heat transfer parameter, and the discharge current; If the battery discharge temperature exceeds a second preset operating temperature range, the discharge current and the feedback current of the power battery are reduced.

5. The method according to claim 4, characterized in that The reducing the discharge current and the feedback current of the power battery includes: When the actual battery temperature is greater than or equal to a first threshold and less than a second threshold, reducing the discharge current and the feedback current according to a third ratio; When the actual battery temperature is greater than or equal to a second threshold and less than a third threshold, reducing the discharge current and the feedback current according to a fourth ratio; When the actual battery temperature is greater than or equal to a third threshold and less than a fourth threshold, the discharge current and the feedback current are reduced according to a fifth ratio; wherein the third ratio is greater than the fourth ratio, the fourth ratio is greater than the fifth ratio, the first threshold is less than the second threshold, the second threshold is less than the third threshold, and the third threshold is less than a maximum temperature value in the second preset operating temperature range.

6. The method according to claim 1, characterized in that The determining of the current battery usage scenario when the thermal management system fails includes: Get the status of the thermal management system; If the state of the thermal management system is a failure state, obtaining the charging information and vehicle speed of the vehicle; If the charging information of the vehicle is a charging state, the battery usage scenario is a charging scenario; If the vehicle speed is greater than the target vehicle speed, the battery usage scenario is a driving scenario.

7. A control device for a battery management system, characterized in that: The control method of the battery management system according to any one of claims 1 to 6 is used, wherein the device comprises: The determination module is used to determine the current battery usage scenario and obtain the actual battery temperature and battery power of the power battery when the thermal management system fails. a first control module, configured to control an actual charging current of the power battery according to the actual battery temperature and the battery power level, so that the power battery is within a first preset operating temperature range, if the battery usage scenario is a charging scenario; The second control module is used to control the discharge current and feedback current of the power battery according to the actual battery temperature and the battery power if the battery usage scenario is a driving scenario, so that the power battery is within a second preset operating temperature range.

8. A controller, characterized in that: The controller includes: a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the control method for the battery management system according to any one of claims 1 to 6 is implemented.

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