Control method and device of battery management system and controller

Abstract

The invention discloses a control method and device of a battery management system and a controller, and the method comprises the steps: determining a current battery use scene in a failure state of a thermal management system, and obtaining the actual battery temperature and the battery electric quantity of a power battery; if the battery use scene is a charging scene, controlling the actual charging current of the power battery according to the actual battery temperature and the battery electric quantity, so that the power battery is in a first preset working temperature range; and if the battery use scene is a driving scene, controlling a discharge current and a feedback current of the power battery according to the actual battery temperature and the battery electric quantity, so that the power battery is in a second preset working temperature range. Therefore, during the period of failure of thermal management of the vehicle, a certain use and disposal space can still be provided for customers, the abuse risk of the battery during the period without thermal management capability is greatly reduced, and the loss is reduced to the greatest extent.

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 battery in new energy vehicles has a suitable operating temperature. The power battery thermal management system will be turned on when the temperature is too high or too low to adjust the ambient temperature of the power battery so that the power battery is at a suitable 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 without 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, the actual charging current of the power battery is controlled 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 in 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, the heat transfer parameter of the power battery, and a charging coefficient of the heat transfer parameter at 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 each charging stage of the power battery 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 the 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 according to 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;

[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 taken 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 the 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 according to 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, the heat transfer parameter of the power battery, the 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 the second threshold and less than the 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 the 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 charging information and vehicle speed of the vehicle;

[0035] If the charging information of the vehicle is a charging state, then 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 in a second preset operating temperature range.

[0041] According to a third aspect of the present invention, a controller is provided, the controller comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, the processor executing the aforementioned control method of 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, which determines the current battery usage scenario and obtains the actual battery temperature and battery power of the power battery when the thermal management system fails; if the battery usage scenario is a charging scenario, the actual charging current of the power battery is controlled according to the actual battery temperature and the battery power, so that the power battery is in a first preset operating temperature range; if the battery usage scenario is a driving scenario, the discharge current and 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. In this way, during the period when the vehicle thermal management fails, it can still provide customers with a certain amount of use and disposal space, and greatly reduce the risk of abuse of the battery during the period when there is no thermal management capability, minimizing 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 according to 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 listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present invention. Also, throughout the accompanying drawings, the same reference figures are used to represent the same components. In the drawings:

[0046] Figure 1 A flow chart of a control method of 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] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here 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 claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are 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, further definition and explanation thereof is not required in subsequent drawings.

[0051] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0052] The embodiment of the present invention provides a control method for a battery management system, 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, and a power battery is provided in the vehicle. The power battery should not be too hot or too cold when working. In other words, the power battery has a suitable temperature range, generally between 10-30 degrees. However, the working environment of the vehicle is very wide, ranging from -20 to 50 degrees.

[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 within the appropriate temperature range.

[0056] However, during the actual use of the vehicle, problems may occur in the thermal management system, resulting in the loss of the ability to regulate temperature. But at this time, the owner may not have had time to send the vehicle for repair. If the power battery is still used according to the previous charge and discharge map when the thermal management system fails, the temperature of the power battery may exceed the appropriate temperature range, which may cause abuse of the power battery. Because when the temperature is too low, the power battery is more prone to lithium ion cycling, and when the temperature is too high, the stability of the positive electrode structure decays. Improper power battery temperature will cause rapid decay of battery capacity 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 have different control strategies, in this embodiment, the 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, then 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 status of the thermal management system is used to indicate whether the thermal management system is operating normally. The status of the thermal management system includes a normal state and a failure state. If the status of the thermal management system is a normal state, the thermal management system can normally adjust the temperature of the power battery. If the status of the thermal management system is a failure state, it means that the thermal management system has lost the ability to adjust the temperature of the power battery.

[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 distinguish what battery usage scenario the vehicle is currently in. If the charging information shows that the power battery is in a charging state, it means that the vehicle is being charged, that is, the battery usage scenario is a charging scenario. If the speed is greater than the target speed, it means that the vehicle is driving, and the power battery is discharging at this time, and the battery usage scenario is a driving scenario. Among them, the target speed is a smaller value, which is used 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, the actual charging current of the power battery is controlled 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 when charging, it is necessary to predict the battery charging temperature of the power battery at different charging stages. If the battery charging temperature exceeds the first preset operating temperature range, corresponding control is required, generally 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 when discharging, it is necessary to predict the battery discharge temperature of the power battery when discharging. If the battery discharge temperature exceeds the second preset operating temperature range, corresponding control is required, generally reducing the discharge current and feedback current of the power battery, thereby reducing heat accumulation. Among them, the feedback 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 of the power battery in the charging scenario, and the second preset operating temperature range refers to the appropriate operating temperature range of the power battery in the discharging scenario. Among them, 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 mostly overlapped.

[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, the heat transfer parameter of the power battery, and a charging coefficient of the heat transfer parameter at 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 power refers to the battery power corresponding to the start of this charging. The target charging current of each charging stage can be obtained according to the preset charging map in the prior art. In the case of thermal management failure, the temperature rise of the power battery is mainly related to the charging current and the heat transfer parameters. In this embodiment, the heat transfer parameters may include the specific heat capacity of different positions of 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 we found in actual experiments that even in the same charging stage, if the starting power of charging 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 is not difficult to understand that the starting power of charging is different, even if the charging current is the same in the same charging stage, the corresponding temperature rise rate is slightly different. Based on this, this embodiment corrects the charging coefficient of the heat transfer parameter through a large number of temperature rise rate calibration experiments. Thus, the relationship between temperature rise, charging current and heat transfer parameters is fitted.

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

[0082] Then, the target charging current corresponding to each subsequent charging stage can be determined based on the battery power, and the temperature rise of each charging stage can be calculated by combining the heat transfer parameter, the charging coefficient of the heat transfer parameter in each charging stage, and the target charging current corresponding to each charging stage. According to the temperature rise of each charging stage and the current actual battery temperature of the power battery, the battery charging temperature corresponding to each subsequent charging stage of the power battery can be predicted.

[0083] For the battery charging temperature corresponding to each subsequent charging stage, if the battery charging temperature of 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 many ways to reduce the actual charging current of the power battery, which can be to discount the charging current in each charging stage, or to discount the charging current in stages, or to combine the above two situations. Specifically:

[0085] In one embodiment, if the battery charging temperature exceeds the first preset operating temperature range, the actual charging current of each charging stage of the power battery 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 continues to be reduced, such as 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 the first preset operating temperature range, the actual charging current in the current charging stage is reduced, and 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 according to 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;

[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 taken 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] It is easy to understand that when the battery charging temperature exceeds the first preset operating temperature range, the current can be reduced 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 in each subsequent charging stage is predicted. If the battery charging temperature exceeds the first preset operating temperature range, the second ratio is reduced, and the actual charging current in the current charging stage is continued to be reduced, and the battery charging temperature in each subsequent charging stage is predicted again. If the battery charging temperature is within the first preset operating temperature range, charging is performed according to the actual charging current after the current reduction. If it still exceeds the first preset operating temperature range, the current reduction continues.

[0091] However, it is necessary to set a minimum current 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 current 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 current 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 taken 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, power batteries are discharging most of the time, but when braking, the vehicle will recover energy, and the power battery will be charged briefly at this time. For power batteries, there is both discharge current and feedback current. Therefore, in driving scenarios, the discharge current and feedback current need to be controlled. The 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, the heat transfer parameter of the power battery, the 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 the heat accumulation of the power battery is larger during the initial discharge, and then gradually becomes flat. Different battery capacities have different discharge coefficients of corresponding heat transfer parameters.

[0097] In the prior art, the temperature rise of the power battery is mainly related to the discharge current and the heat transfer parameters. In the case of thermal management failure, this embodiment corrects the discharge coefficient of the heat transfer parameters through a large number of discharge calibration experiments, thereby fitting the relationship between the temperature rise and the discharge current and the heat transfer parameters.

[0098] Then, according to the heat transfer parameter of the power battery, the discharge coefficient of the heat transfer parameter and the discharge current, combined with the actual battery temperature of the current 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. The 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 the second threshold and less than the 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 the maximum temperature value in the second preset operating temperature range.

[0102] This embodiment sets three thresholds, namely, the first threshold, the second threshold and the third threshold. Through the three thresholds, the battery temperature rise is divided into three different stages, and then the discharge current and the feedback current are 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 is, and the greater the current reduction is.

[0103] For example, the first threshold T1<the second threshold T2<the third threshold T3, T3 is 60 degrees, T2 is 55 degrees, 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 discharge current after the reduction is 40A.

[0105] The degree of power discount is related to the temperature threshold setting boundary. The higher the temperature threshold, the greater the discount. Different models have different usage scenarios. If you focus more on the user's driving experience, the temperature threshold is higher, and if you want to maintain the service life of the car, the temperature threshold is lower.

[0106] In addition, in order to more widely meet the needs of different scenarios, the flow reduction ratio in the charging scene and driving scene can be limited in combination with other influencing factors. Because users focus on different aspects, the weight of each influencing factor can be set by the user. The influencing factors of 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. Then adjust the aforementioned flow reduction ratios according to the weights of each influencing factor entered by the user.

[0107] In summary, the control method of a battery management system provided in the embodiment of this specification determines the current battery usage scenario and obtains the actual battery temperature and battery power of the power battery when the thermal management system fails; if the battery usage scenario is a charging scenario, the actual charging current of the power battery is controlled according to the actual battery temperature and the battery power, so that the power battery is in a first preset operating temperature range; if the battery usage scenario is a driving scenario, the discharge current and 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. In this way, during the period when the vehicle thermal management fails, it can still provide customers with a certain amount of use and disposal space, and greatly reduce the risk of abuse of the battery during the period without thermal management capability, minimizing losses.

[0108] Based on the same inventive concept, 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 in a second preset operating temperature range.

[0112] Optionally, the first control module is further used for:

[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, the heat transfer parameter of the power battery, and a charging coefficient of the heat transfer parameter at 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 used for:

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

[0119] Optionally, the first control module is further used for:

[0120] If the battery charging temperature exceeds the 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 according to 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;

[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 taken 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 used for:

[0125] If the reduced actual charging current is greater than the current threshold, re-predicting the battery charging temperature of the power battery according to 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 used for:

[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, the heat transfer parameter of the power battery, the 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 used for:

[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 the second threshold and less than the 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 the 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 charging information and vehicle speed of the vehicle;

[0138] If the charging information of the vehicle is a charging state, then 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 control device of a battery management system provided in the embodiment of this specification determines the current battery usage scenario and obtains the actual battery temperature and battery power of the power battery when the thermal management system fails; if the battery usage scenario is a charging scenario, the actual charging current of the power battery is controlled according to the actual battery temperature and the battery power, so that the power battery is in a first preset operating temperature range; if the battery usage scenario is a driving scenario, the discharge current and 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. In this way, during the period when the vehicle thermal management fails, it can still provide customers with a certain amount of use and disposal space, and greatly reduce the risk of abuse of the battery during the period when there is no thermal management capability, minimizing losses.

[0141] Those skilled in the art can 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 are electrically connected to each other directly or indirectly to achieve signal transmission or interaction. For example, these elements can be electrically connected to each other through 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 (for example, 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 (Random Access Memory, RAM), read-only memory (Read On ly Memory, ROM), programmable read-only memory (Programmable Read-Only Memory, PROM), erasable read-only memory (Erasab le Programmable Read-Only Memory, EPROM), electrically erasable read-only memory (Electrical Erasable Programmable 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 can 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 installed in the vehicle body, the controller being used to implement the control method of the battery management system described above. The vehicle is a new energy vehicle, and the vehicle also includes a power battery, a battery management system and a thermal management system.

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

[0151] The above are only various embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope 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, the actual charging current of the power battery is controlled 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 in a second preset operating temperature range.

2. The method according to claim 1, characterized in that 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, the heat transfer parameter of the power battery, and a charging coefficient of the heat transfer parameter at each charging stage; If the battery charging temperature exceeds a first preset operating temperature range, the actual charging current of the power battery is reduced.

3. The method according to claim 2, 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 each charging stage of the power battery is reduced according to a first ratio.

4. The method according to claim 2, 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 the 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 according to 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 re-predicted battery charging temperature of the power battery exceeds the first preset operating temperature range, the next adjacent charging stage is taken 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.

5. The method according to claim 4, characterized in that The reducing the actual charging current in the target stage according to the second ratio comprises: If the reduced actual charging current is greater than the current threshold, re-predicting the battery charging temperature of the power battery according to 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.

6. The method according to claim 1, characterized in that 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, the heat transfer parameter of the power battery, the 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.

7. The method according to claim 6, 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 the second threshold and less than the 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 the maximum temperature value in the second preset operating temperature range.

8. 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, then 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.

9. A control device for a battery management system, characterized in that: include: 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 in a second preset operating temperature range.

10. 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 of the battery management system described in any one of claims 1 to 8 is implemented.

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