Battery power switching control method and device, battery management system and vehicle

Abstract

The invention provides a battery power switching control method and device, a battery management system and a vehicle. According to a current detection value and a preset switching speed of a power battery in a first power state under the condition that the power battery runs in the first power state, the switching speed of the power battery in the first power state is determined; and determining a charge-discharge capacity predicted value of the power battery in the first power state, and if the charge-discharge capacity predicted value represents that the power battery reaches the critical moment of power state switching, determining a working voltage predicted value of the power battery in the power state switching process based on the preset switching speed, and determining the target switching speed based on the size relationship between the working voltage predicted value and the preset charge-discharge voltage threshold value, so as to control the power battery to be switched from the first power state to the second power state based on the target switching speed, thereby ensuring that the peak discharge capability or the peak feedback capability of the power battery is fully exerted, and improving the switching efficiency of the power battery. And the risk of over-charging or over-discharging of the power battery is effectively reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of vehicles, in particular to a battery power switching control method and device, a battery management system and a vehicle. BACKGROUND

[0002] With the development of power battery technologies, users have increasingly obvious demands for the power performance and driving range of vehicles. The state of power (SOP) of a power battery reflects the peak discharge capacity and peak feedback capacity of the power battery. The power battery is usually configured with multiple power states, such as a 30s power state, a 60s power state, a continuous power state, and the like, to meet the power demands of the vehicle under different working conditions.

[0003] In the prior art, during the power state switching of the power battery, it is impossible to effectively reduce the risk of overcharging or overdischarging of the power battery while ensuring that the power battery fully exerts its peak discharge capacity or peak feedback capacity. SUMMARY

[0004] To solve the above technical problems, the present application provides a battery power switching control method and device, a battery management system and a vehicle to solve the problem that it is impossible to effectively reduce the risk of overcharging or overdischarging of the power battery while ensuring that the power battery fully exerts its peak discharge capacity or peak feedback capacity in the prior art.

[0005] To achieve the above technical purposes, the embodiments of the present application provide the following technical solutions: In a first aspect, the present specification provides a battery power switching control method, comprising: In a case where a power battery operates in a first power state, a charge-discharge capacity prediction value of the power battery in the first power state is determined according to a current detection value of the power battery in the first power state and a preset switching speed of the power battery switching from the first power state to a second power state; the charge-discharge current limit value of the power battery in the first power state is greater than the charge-discharge current limit value in the second power state; If the charge-discharge capacity prediction value represents a critical time of the power battery reaching the power state switching, a working voltage prediction value of the power battery in the power state switching process is determined based on the preset switching speed; A target switching speed of the power battery in the power state switching process is determined based on the size relationship between the working voltage prediction value and a preset charge-discharge voltage threshold of the power battery; The power battery is controlled to switch from the first power state to the second power state at the target switching speed.

[0006] In an embodiment, the working voltage prediction value of the power battery at the target time point is determined based on the preset switching speed, the current detection value and the state of charge detection value of the power battery at the critical time point, and the target time point is any time point in the power state switching process. The open-circuit voltage prediction value and the polarization voltage prediction value of the power battery at the target time point are determined based on the preset switching speed, the current detection value and the state of charge detection value of the power battery at the critical time point, and the target time point is any time point in the power state switching process. The working voltage prediction value of the power battery at the target time point is determined based on the difference between the open-circuit voltage prediction value and the polarization voltage prediction value.

[0007] In an embodiment, the open-circuit voltage prediction value and the polarization voltage prediction value of the power battery at the target time point are determined based on the preset switching speed, the current detection value and the state of charge detection value of the power battery at the critical time point, and the target time point is any time point in the power state switching process. The current prediction value of the power battery at each time point in the power state switching process is determined based on the current detection value of the power battery at the critical time point and the preset switching speed. The state of charge prediction value of the power battery at the target time point is determined based on the state of charge detection value and the current prediction value at each time point in the power state switching process. The open-circuit voltage prediction value and the polarization resistance prediction value of the power battery at the target time point are determined based on the state of charge prediction value and the target corresponding relationship, and the target corresponding relationship includes the corresponding relationship between the state of charge of the power battery and the open-circuit voltage and the polarization resistance. The polarization voltage prediction value is determined based on the current prediction value of the power battery at the target time point and the polarization resistance prediction value.

[0008] In an embodiment, the charge and discharge capacity prediction value of the power battery in the first power state is determined according to the current detection value of the power battery in the first power state and the preset switching speed of the power battery switching from the first power state to the second power state. The current prediction value of the power battery at each time point in the power state switching process is determined based on the current detection value of the power battery at the current time point and the preset switching speed. The actual charge and discharge capacity of the power battery in the first power state is determined according to the current detection value of the power battery at each time point in the first power state, and the target reserved charge and discharge capacity of the power battery in the power state switching process is determined according to the current prediction value of the power battery at each time point in the power state switching process. The sum of the actual charge-discharge capacity and the target reserved charge-discharge capacity is used to determine a charge-discharge capacity prediction value of the power battery in the first power state.

[0009] In an embodiment, determining whether the charge-discharge capacity prediction value represents a critical moment when the power battery reaches a power state switching includes: If the charge-discharge capacity prediction value is greater than or equal to a charge-discharge capacity threshold of the power battery in the first power state, it is determined that the critical moment is reached. If the charge-discharge capacity prediction value is less than the charge-discharge capacity threshold, it is determined that the critical moment is not reached.

[0010] In an embodiment, based on the size relationship between the working voltage prediction value and a preset charge-discharge voltage threshold of the power battery, a target switching speed of the power battery in the power state switching process is determined, including: Based on the size relationship between the working voltage prediction value and the preset charge-discharge voltage threshold of the power battery, a moment when the working voltage of the power battery reaches the preset charge-discharge voltage threshold is determined, and based on the preset switching speed, a candidate end moment of the power state switching is determined. According to the time difference between the moment when the working voltage of the power battery reaches the preset charge-discharge voltage threshold and the candidate end moment, a target switching speed of the power battery in the power state switching process is determined.

[0011] In an embodiment, according to the difference between the moment when the working voltage of the power battery reaches the preset charge-discharge voltage threshold and the candidate end moment, a target switching speed of the power battery in the power state switching process is determined, including: If the time difference is less than zero, a first switching speed higher than the preset switching speed is determined as the target switching speed. If the time difference is greater than zero, a second switching speed lower than the preset switching speed is determined as the target switching speed. If the time difference is equal to zero, the preset switching speed is determined as the target switching speed.

[0012] In a second aspect, the embodiments of the present specification provide a battery power switching control device, the device comprising: The first processing module is configured to, when the power battery operates in a first power state, determine a charge-discharge capacity prediction value of the power battery in the first power state according to a current detection value of the power battery in the first power state and a preset switching speed of the power battery switching from the first power state to a second power state; the charge-discharge current limit value of the power battery in the first power state is greater than the charge-discharge current limit value of the power battery in the second power state. The second processing module is configured to, if the charge-discharge capacity prediction value represents a critical time when the power battery reaches power state switching, determine a working voltage prediction value of the power battery in a power state switching process based on the preset switching speed. The third processing module is configured to determine a target switching speed of the power battery in the power state switching process based on a size relationship between the working voltage prediction value and a preset charge-discharge voltage threshold of the power battery. The fourth processing module is configured to control the power battery to switch from the first power state to the second power state at the target switching speed.

[0013] In a third aspect, the embodiments of the present specification provide a battery management system, comprising a memory and at least one processor; wherein the memory is configured to store one or more computer instructions, wherein the one or more computer instructions are executed by the at least one processor to implement the battery power switching control method according to any one of the above.

[0014] In a fourth aspect, the embodiments of the present specification provide a vehicle, comprising a power battery and a battery management system according to the above.

[0015] In a fifth aspect, the embodiments of the present specification provide a computer readable storage medium, wherein the computer readable storage medium stores a computer program, and the computer program is executed by a processor to implement the battery power switching control method according to any one of the above.

[0016] In a sixth aspect, the embodiments of the present specification provide a computer program product or a computer program, wherein the computer program product comprises a computer program stored in a computer readable storage medium; a processor of a computer device reads the computer program from the computer readable storage medium, and the processor executes the computer program to implement the battery power switching control method according to any one of the above.

[0017] It can be seen from the technical solution that the embodiment of the application provides a battery power switching control method, a battery power switching control device, a battery management system and a vehicle. In the case that the power battery operates in a first power state, the charging and discharging capacity prediction value of the power battery in the first power state is determined according to the current detection value of the power battery in the first power state and the preset switching speed of the power battery from the first power state to a second power state. The charging and discharging current limit value of the power battery in the first power state is greater than the charging and discharging current limit value in the second power state. If the charging and discharging capacity prediction value represents that the power battery reaches the critical moment of power state switching, the working voltage prediction value of the power battery in the power state switching process is determined based on the preset switching speed, and the target switching speed of the power battery in the power state switching process is determined based on the size relationship between the working voltage prediction value and the preset charging and discharging voltage threshold of the power battery, so as to control the power battery to switch from the first power state to the second power state based on the target switching speed. Therefore, in the process that the power battery switches from the first power state to the second power state, the charging and discharging capacity of the power battery and the voltage protection of the power battery can be comprehensively considered, and the risk of overcharging or overdischarging of the power battery can be effectively reduced while ensuring that the power battery fully exerts its peak discharge capacity or peak feedback capacity. BRIEF DESCRIPTION OF DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced. Obviously, the drawings in the following description are only embodiments of the application, and other drawings can be obtained by those skilled in the art without creative labor on the basis of the provided drawings.

[0019] Figure 1 A flowchart of a battery power switching control method provided for the embodiments of the present specification.

[0020] Figure 2 A schematic diagram of a charging and discharging capacity prediction value of a power battery in a first power state provided for the embodiments of the present specification.

[0021] Figure 3 A structural schematic diagram of a battery power switching control device provided for the embodiments of the present specification. DETAILED DESCRIPTION

[0022] Unless otherwise defined, technical terms or scientific terms used in the embodiments of the present specification shall have the meanings as understood by a person of ordinary skill in the art to which the embodiments of the present specification belong. The terms "first", "second", and similar terms used in the embodiments of the present specification do not denote any order, quantity, or importance, but are used to avoid confusion between the components.

[0023] Unless the context requires otherwise, throughout the specification, "plurality" means "at least two", "comprises" is interpreted as an open, inclusive meaning, i.e. "including, but not limited to". In the description of the specification, the terms "one embodiment", "some embodiments", "exemplary embodiments", "example", "specific example" or "some examples" are intended to mean that a particular feature, structure, material or characteristic included in at least one embodiment or example of the specification. The illustrative representation of the above terms does not necessarily mean the same embodiment or example.

[0024] The technical solutions in the embodiments of the present specification will be described clearly and completely in the following with reference to the drawings in the embodiments of the present specification. Obviously, the described embodiments are only part of the embodiments of the present specification, not all. Based on the embodiments in the present specification, all other embodiments obtained by a person of ordinary skill in the art without creative labor are within the scope of protection of the present specification.

[0025] SUMMARY As described in the background, with the development of power battery technologies, users' demands for vehicle power and driving range are increasingly apparent. Among them, the power state of the power battery reflects the peak discharge capacity and peak feedback capacity of the power battery. The power battery is usually configured with multiple power states, such as 30s power state, 60s power state, continuous power state, etc., to meet the power demand of the vehicle under different working conditions.

[0026] In the prior art, during the power state switching of the power battery, the power state is usually switched according to the actual charge and discharge capacity of the power battery, or the power state is switched according to the actual execution time of the current power state. It is unable to effectively reduce the risk of overcharging or overdischarging of the power battery while ensuring that the power battery fully develops its peak discharge capacity or peak feedback capacity.

[0027] In order to solve the problem that in the traditional method, the power battery cannot fully exert its peak discharge capacity or peak feedback capacity while effectively reducing the risk of overcharging or overdischarging of the power battery, in the technical scheme of the present application, a battery power switching control scheme is provided. In the case where the power battery operates in a first power state, according to the current detection value of the power battery in the first power state and the preset switching speed of the power battery switching from the first power state to a second power state, the charge and discharge capacity prediction value of the power battery in the first power state is determined. The charge and discharge current limit value of the power battery in the first power state is greater than that in the second power state. If the charge and discharge capacity prediction value represents that the power battery reaches the critical moment of power state switching, the working voltage prediction value of the power battery in the power state switching process is determined based on the preset switching speed, and the target switching speed of the power battery in the power state switching process is determined based on the size relationship between the working voltage prediction value and the preset charge and discharge voltage threshold of the power battery, so as to control the power battery to switch from the first power state to the second power state based on the target switching speed. Thus, in the process of switching the power battery from the first power state to the second power state, the charge and discharge capacity of the power battery and the voltage protection of the power battery can be comprehensively considered, and thus the risk of overcharging or overdischarging of the power battery can be effectively reduced while ensuring that the power battery fully exerts its peak discharge capacity or peak feedback capacity.

[0028] Based on the above inventive concept, the battery power switching control scheme provided by the embodiments of the present application is exemplarily described below.

[0029] Exemplary method The embodiments of the present application provide a battery power switching control method, as shown in the figure, the method comprises: Figure 1 S101, in the case where the power battery operates in a first power state, according to the current detection value of the power battery in the first power state and the preset switching speed of the power battery switching from the first power state to a second power state, the charge and discharge capacity prediction value of the power battery in the first power state is determined; the charge and discharge current limit value of the power battery in the first power state is greater than that in the second power state.

[0030] Specifically, the first power state and the second power state of the power battery can be any two power states of the power battery, and the charge and discharge current limit value of the power battery in the first power state can be greater than that in the second power state. For example, the first power state can be a 30s power state, and the second power state can be a 60s power state.

[0031] ​When the power battery is operating in the first power state, for example, when the power battery is discharging in the first power state, or when it is performing energy feedback in the first power state, the predicted value of the charge and discharge capacity of the power battery in the first power state can be obtained in real time.

[0032] Specifically, for any moment during the operation of the power battery in the first power state, the predicted charge / discharge capacity of the power battery in the first power state at that current moment can be the predicted total charge / discharge capacity of the power battery from the initial moment of switching to the first power state to the final moment of switching to the second power state, assuming the power battery begins switching to the second power state at the current moment. In practice, the predicted charge / discharge capacity of the power battery in the first power state can be determined based on the current detection value of the power battery in the first power state and the preset switching speed of the power battery switching from the first power state to the second power state.

[0033] The current detection value of the power battery in the first power state can include the detected charging and discharging current values ​​of the power battery at various moments within the time interval from the initial moment of switching to the first power state to the current moment. The actual charging and discharging capacity of the power battery in the first power state can be determined based on the current detection value. The preset switching speed of the power battery from the first power state to the second power state can be the rate at which the current of the power battery decreases during the switching process. Based on the current detection value of the power battery at the current moment and the rate at which the current decreases, the predicted current value of the power battery during the entire switching process from the first power state to the second power state can be predicted. Furthermore, based on the predicted current value during the power state switching process, the target reserved charging and discharging capacity of the power battery during the power state switching process can be determined. Therefore, based on the actual charging and discharging capacity of the power battery in the first power state and the target reserved charging and discharging capacity during the power state switching process, the predicted charging and discharging capacity of the power battery in the first power state can be determined.

[0034] S102. If the predicted charge / discharge capacity value represents the critical moment when the power battery reaches the power state switching, then based on the preset switching speed, determine the predicted operating voltage value of the power battery during the power state switching process.

[0035] Specifically, for any time point in the process that the power battery operates in the first power state, whether the power battery reaches the critical time point of the power state switching can be determined according to the charge-discharge capacity prediction value of the power battery in the first power state determined at the time point. The critical time point of the power state switching is the latest time point at which the power battery starts to switch from the first power state to the second power state, that is, if the power battery starts to switch from the first power state to the second power state later than the critical time point, there is a risk of overcharging or over-discharging of the power battery. For example, whether the power battery reaches the critical time point of the power state switching can be determined according to the size relationship between the charge-discharge capacity prediction value of the power battery in the first power state determined at the time point and the charge-discharge capacity threshold of the power battery in the first power state.

[0036] If the power battery does not reach the critical time point of the power state switching, the power battery can continue to operate in the first power state, and if the power battery reaches the critical time point of the power state switching, the power battery needs to be controlled to start to switch from the first power state to the second power state at the current time point, so as to effectively reduce the risk of overcharging or over-discharging of the power battery while ensuring that the power battery fully develops its peak discharge capacity or peak feedback capacity.

[0037] In implementation, if the power battery reaches the critical time point of the power state switching at the current time point, the working voltage prediction value of the power battery at each time point in the power state switching process, that is, the process that the power battery switches from the first power state to the second power state, can be further determined according to the preset switching speed of the power battery. In this way, whether the power battery will be overcharged or over-discharged in the process that the power battery starts to switch from the first power state to the second power state at the current time point according to the preset switching speed can be determined according to the working voltage prediction value of the power battery at each time point in the power state switching process, so as to further reduce the risk of overcharging or over-discharging of the power battery.

[0038] S103, determining a target switching speed of the power battery in the power state switching process based on the size relationship between the working voltage prediction value and the preset charge-discharge voltage threshold of the power battery.

[0039] Specifically, the target switching speed of the power battery in the power state switching process can be determined according to the size relationship between the working voltage prediction value of the power battery at each time point in the state switching process and the preset charge-discharge voltage threshold of the power battery.

[0040] For example, the overcharge or overdischarge of the power battery during the process of switching from the first power state to the second power state at the preset switching speed can be determined according to the size relationship between the working voltage prediction value of the power battery at each moment during the power state switching process and the preset charging and discharging voltage threshold of the power battery, and the target switching speed of the power battery during the power state switching process can be determined according to the determination result. For example, if it is determined that overcharge or overdischarge will occur, the target switching speed can be determined to be greater than the preset switching speed, so as to further reduce the risk of overcharge or overdischarge of the power battery during the process of switching from the first power state to the second power state; if it is determined that overcharge or overdischarge will not occur, the preset switching speed can be determined as the target switching speed, or the target switching speed can be determined to be less than the preset switching speed, so as to effectively avoid the risk of overcharge or overdischarge of the power battery during the process of switching from the first power state to the second power state, and make the power battery fully exert its peak discharge capacity or peak feedback capacity.

[0041] S104、According to the target switching speed, control the power battery to switch from the first power state to the second power state.

[0042] Specifically, during the process of controlling the power battery to switch from the first power state to the second power state based on the target switching speed, the charging and discharging current of the power battery can be gradually reduced according to the target switching speed until the charging and discharging current of the power battery is less than or equal to the charging and discharging current limit value in the second power state, so as to effectively reduce the risk of overcharge or overdischarge of the power battery during the process of switching from the first power state to the second power state while ensuring that the power battery fully exerts its peak discharge capacity or peak feedback capacity.

[0043] In one possible implementation, the working voltage prediction value of the power battery during the power state switching process is determined, including: Based on the preset switching speed, and the current detection value and the state of charge detection value of the power battery at the critical moment, the open circuit voltage prediction value and the polarization voltage prediction value of the power battery at the target moment are determined, the target moment being any moment during the power state switching process; Based on the difference between the open circuit voltage prediction value and the polarization voltage prediction value, the working voltage prediction value of the power battery at the target moment is determined.

[0044] Specifically, the open-circuit voltage of the power battery can be the voltage difference between the positive electrode and the negative electrode of the power battery when the power battery is not charged and discharged, and the state of charge of the power battery can be reflected by the open-circuit voltage of the power battery. Considering that the power battery is not constant-current charged and discharged in the first power state, the polarization voltage of the power battery can be the influence of the polarization reaction caused by the change of the charging and discharging current on the working voltage of the power battery during the charging and discharging process of the power battery.

[0045] The target moment can be any moment in the process of switching the power battery from the first power state to the second power state. In the implementation, the open-circuit voltage prediction value and the polarization voltage prediction value of the power battery at the target moment can be determined based on the preset switching speed of the power battery from the first power state to the second power state, the current detection value and the state of charge detection value of the power battery at the critical moment, and the difference between the open-circuit voltage prediction value and the polarization voltage prediction value of the power battery at the target moment can be calculated, and the difference is taken as the prediction value of the working voltage of the power battery at the target moment. Therefore, by determining the working voltage prediction value of the power battery according to the open-circuit voltage prediction value and the polarization voltage prediction value of the power battery at the same time, the influence of the polarization reaction caused by the charging and discharging process of the power battery on the working voltage of the power battery can be fully considered, so as to ensure the accuracy of the working voltage prediction value of the power battery, and then according to the size relationship between the working voltage prediction value of the power battery and the preset charging and discharging voltage threshold of the power battery, the target switching speed of the power battery in the power state switching process can be determined, and in the process of controlling the power battery to switch the power state according to the target switching speed, the risk of overcharging or overdischarging of the power battery in the process of switching the power battery from the first power state to the second power state can be effectively reduced while ensuring that the peak discharge capacity or peak feedback capacity of the power battery is fully utilized.

[0046] In a feasible implementation, the determination of the open-circuit voltage prediction value and the polarization voltage prediction value of the power battery at the target moment based on the preset switching speed and the current detection value and the state of charge detection value of the power battery at the critical moment comprises: determining the current prediction value of the power battery at each moment in the power state switching process based on the current detection value of the power battery at the critical moment and the preset switching speed; determining the state of charge prediction value of the power battery at the target moment based on the current prediction value at each moment in the power state switching process and the state of charge detection value; determining the open-circuit voltage prediction value and the polarization resistance prediction value of the power battery at the target moment based on the state of charge prediction value and a target corresponding relationship, wherein the target corresponding relationship comprises the corresponding relationship between the state of charge of the power battery and the open-circuit voltage and the polarization resistance. The polarization voltage prediction value is determined based on the predicted current value of the power battery at the target time and the predicted polarization resistance value.

[0047] Specifically, the predicted current value of the power battery at each moment during the transition from the first power state to the second power state can be determined based on the current detection value of the power battery at the critical moment and the preset switching speed. For example, for any moment during the power state switching process, the predicted current value I at that moment is... p It can be shown in equation (1): (1) In the formula, I c The current detection value at the critical moment is M, the preset switching speed is M, and t is the difference between this moment and the moment when the power battery starts to switch from the first power state to the second power state.

[0048] Specifically, the predicted state of charge (SOC) value of the power battery at each moment during the transition from the first power state to the second power state can be determined based on the detected SOC value at the critical moment and the predicted current value at each moment during the transition from the first power state to the second power state. For example, for any moment t during the power state transition process... k The predicted state of charge (SOC) at that moment p It can be shown in equation (2): / C (2) In the formula, SOC c t represents the state of charge (SOC) value of the power battery at the critical moment. e C represents the moment when the power battery begins to switch from the first power state to the second power state, and C represents the rated capacity of the power battery.

[0049] Therefore, based on the detected state of charge (SOC) value of the power battery at the critical moment, and the predicted current value of the power battery at each moment during the process of switching from the first power state to the second power state, the predicted SOC value of the power battery at each moment during the power state switching process can be determined quickly and accurately.

[0050] The open-circuit voltage corresponding to the state-of-charge prediction value of the power battery at the target moment and the polarization resistance corresponding to the state-of-charge prediction value of the power battery at the target moment can be determined according to the correspondence between the state-of-charge of the power battery and the open-circuit voltage and the polarization resistance, the open-circuit voltage corresponding to the state-of-charge prediction value of the power battery at the target moment is taken as the open-circuit voltage prediction value of the power battery at the target moment, the polarization resistance corresponding to the state-of-charge prediction value of the power battery at the target moment is taken as the polarization resistance prediction value of the power battery at the target moment, and the product of the current prediction value and the polarization resistance prediction value of the power battery at the target moment is taken as the polarization voltage prediction value of the power battery at the target moment. That is, for any moment in the power state switching process, the working voltage prediction value U p may be as shown in formula (3): (3) In the formula, U OCVp is the open-circuit voltage prediction value of the power battery at the moment, R p is the polarization resistance prediction value of the power battery at the moment.

[0051] Therefore, the working voltage prediction value of the power battery at each moment in the power state switching process can be quickly and accurately predicted in this way.

[0052] In a feasible implementation, the charge-discharge capacity prediction value of the power battery in the first power state is determined according to the current detection value of the power battery in the first power state and a preset switching speed of the power battery switched from the first power state to a second power state, and the method comprises: determining the current prediction value of the power battery at each moment in the power state switching process based on the current detection value of the power battery at the current moment and the preset switching speed; determining the actual charge-discharge capacity of the power battery in the first power state according to the current detection value of the power battery at each moment in the first power state, and determining a target reserved charge-discharge capacity in the power state switching process according to the current prediction value of the power battery at each moment in the power state switching process; determining the charge-discharge capacity prediction value of the power battery in the first power state according to the sum of the actual charge-discharge capacity and the target reserved charge-discharge capacity.

[0053] Specifically, for any moment when the power battery is operating in the first power state, the predicted current value of the power battery at each moment during the power state switching process can be determined based on the current detection value of the power battery at the current moment and the preset switching speed of the power battery from the first power state to the second power state. For example, the current detection value of the power battery at the current moment can be substituted into I in equation (1). c And, substitute the difference between that time and the current time into t in (1) to obtain the predicted current value of the power battery at that time.

[0054] Specifically, the time integral result of the current detection value of the power battery in the first power state can be determined based on the current detection value at each moment during the first power state, and this time integral result is used as the actual charge / discharge capacity of the power battery in the first power state. Simultaneously, the time integral result of the predicted current value of the power battery during the power state switching process can be determined based on the predicted current value at each moment during the power state switching process, and this time integral result is used as the target reserved charge / discharge capacity of the power battery during the power state switching process. It can be understood that this target reserved charge / discharge capacity can be the predicted charge / discharge capacity of the power battery during the power state switching process when the power battery starts switching from the first power state to the second power state at the current moment. Optionally, the predicted charge / discharge capacity of the power battery in the first power state can be as follows: Figure 2 As shown, Figure 2 In the diagram, I1 and I2 are the charging and discharging current limits of the power battery in the first and second power states, respectively, and t0 is the initial moment when the power battery is operating in the first power state. e t is the moment when the power battery begins to switch from the first power state to the second power state. f This is a candidate end time for the power state transition.

[0055] In practice, the sum of the actual charge and discharge capacity of the power battery in the first power state and the target reserved charge and discharge capacity of the power battery during the power state switching process can be used as the predicted value of the charge and discharge capacity of the power battery in the first power state. This allows for the rapid and accurate determination of the predicted value of the charge and discharge capacity of the power battery in the first power state. Furthermore, when controlling the power battery to switch power states based on the predicted value of the charge and discharge capacity in the first power state, it is possible to ensure that the power battery fully utilizes its peak discharge capacity or peak feedback capacity while effectively reducing the risk of overcharging or over-discharging during the transition from the first power state to the second power state.

[0056] In one feasible implementation, determining whether the predicted charge / discharge capacity characterizes the critical moment when the power battery reaches a power state switching condition includes: If the charge-discharge capacity prediction value is greater than or equal to the charge-discharge capacity threshold of the power battery in the first power state, it is determined that the critical moment is reached. If the charge-discharge capacity prediction value is less than the charge-discharge capacity threshold, it is determined that the critical moment is not reached.

[0057] Specifically, the charge-discharge capacity threshold of the power battery in the first power state can be an integral result of the charge-discharge current limit value of the power battery in the first power state and a time limit value of the first power state. The time limit value of the first power state can be a maximum allowed continuous execution time of the charge-discharge current limit value in the first power state, for example, 30s.

[0058] If the charge-discharge capacity prediction value of the power battery in the first power state is greater than or equal to the charge-discharge capacity threshold of the power battery in the first power state, it indicates that there is a risk of overcharging or over-discharging of the power battery if the power battery continues to operate in the first power state. At this time, it can be determined that the power battery reaches the critical moment of power state switching, that is, the power battery needs to be controlled to switch from the first power state to the second power state at the current time, thereby effectively reducing the risk of overcharging or over-discharging of the power battery during the switching from the first power state to the second power state.

[0059] If the charge-discharge capacity prediction value of the power battery in the first power state is less than the charge-discharge capacity threshold of the power battery in the first power state, it can be determined that the power battery does not reach the critical moment of power state switching. At this time, the power battery can continue to operate in the first power state, thereby ensuring that the power battery fully develops its peak discharge capacity or peak feedback capacity.

[0060] In one possible implementation, based on the size relationship between the working voltage prediction value and the preset charge-discharge voltage threshold of the power battery, a target switching speed of the power battery in the power state switching process is determined, including: based on the size relationship between the working voltage prediction value and the preset charge-discharge voltage threshold of the power battery, determining a time when the working voltage of the power battery reaches the preset charge-discharge voltage threshold, and based on the preset switching speed, determining a candidate end time of the power state switching; According to the time difference between the time when the working voltage of the power battery reaches the preset charge-discharge voltage threshold and the candidate end time, the target switching speed of the power battery in the power state switching process is determined.

[0061] Specifically, the preset charge-discharge voltage threshold of the power battery can include a preset charge voltage threshold and a preset discharge voltage threshold, the preset charge voltage threshold can be a voltage threshold for judging whether the power battery is fully charged, and the preset discharge voltage threshold can be a voltage threshold for judging whether the power battery is under-voltage.

[0062] In implementation, the time when the working voltage of the power battery reaches the preset charge-discharge voltage threshold can be determined according to the size relationship between the working voltage prediction value of the power battery at each moment in the power state switching process and the preset charge-discharge voltage threshold of the power battery, for example, the time when the working voltage prediction value is equal to the preset charge-discharge voltage threshold of the power battery can be taken as the time when the working voltage of the power battery reaches the preset charge-discharge voltage threshold. It can be understood that if the working voltage prediction value of the power battery at each moment in the power state switching process is greater than the preset charge-discharge voltage threshold of the power battery, it can be determined that the time when the working voltage of the power battery reaches the preset charge-discharge voltage threshold is later than the candidate end time of the power state switching.

[0063] The candidate end time of the power state switching can be the time when the power battery is switched to the second power state, in the case that the power battery is controlled to switch from the first power state to the second power state at the critical time of the power state switching according to the preset switching speed.

[0064] In implementation, the difference between the current detection value of the power battery at the critical time of the power state switching and the charge-discharge current limit value of the power battery in the second power state can be calculated, and the ratio of the difference to the preset switching speed can be taken as the target time length of the power state switching, and the sum of the critical time of the power state switching and the target time length of the power state switching can be taken as the candidate end time of the power state switching.

[0065] Optionally, the target switching speed of the power battery in the power state switching process can be determined according to the time difference between the time when the working voltage of the power battery reaches the preset charge-discharge voltage threshold and the candidate end time of the power state switching, for example, the target switching speed of the power battery in the power state switching process can be determined according to the positive or negative of the time difference, so as to effectively reduce the risk of overcharge or overdischarge of the power battery in the process of switching from the first power state to the second power state while ensuring that the power battery fully develops its peak discharge capacity or peak feedback capacity.

[0066] It can be understood that the target switching speed of the power battery in the power state switching process can also be determined according to a difference between the working voltage prediction value of the power battery at the candidate end moment of the power state switching and a preset charging and discharging voltage threshold of the power battery. For example, in the discharging process of the power battery, the target switching speed of the power battery in the power state switching process can be negatively correlated with the difference, and in the energy feedback process of the power battery, the target switching speed of the power battery in the power state switching process can be positively correlated with the difference, so that the risk of overcharging or overdischarging of the power battery in the process of switching from the first power state to the second power state can be effectively reduced while ensuring that the peak discharging capacity or the peak feedback capacity of the power battery is fully utilized.

[0067] In a feasible implementation, the target switching speed of the power battery in the power state switching process is determined according to a difference between a moment when the working voltage of the power battery reaches the preset charging and discharging voltage threshold and the candidate end moment, including: If the time difference is less than zero, a first switching speed higher than the preset switching speed is determined as the target switching speed; If the time difference is greater than zero, a second switching speed lower than the preset switching speed is determined as the target switching speed; If the time difference is equal to zero, the preset switching speed is determined as the target switching speed.

[0068] Specifically, if the difference between the moment when the working voltage of the power battery reaches the preset charging and discharging voltage threshold and the candidate end moment is less than zero, it indicates that the working voltage of the power battery has reached the preset charging and discharging voltage threshold before the candidate end moment is reached, that is, the power battery has a risk of overcharging or overdischarging in the case of power state switching at the preset switching speed. At this time, the first switching speed can be determined as the target switching speed, and the first switching speed can be higher than the preset switching speed to quickly control the power battery to switch from the first power state to the second power state, thereby effectively reducing the risk of overcharging or overdischarging of the power battery.

[0069] If the difference between the moment when the working voltage of the power battery reaches the preset charging and discharging voltage threshold and the candidate end moment is greater than zero, it indicates that the working voltage of the power battery has not reached the preset charging and discharging voltage threshold when the candidate end moment is reached, that is, the power battery still has the ability to discharge or feedback energy. At this time, the second switching speed can be determined as the target switching speed, and the second switching speed can be lower than the preset switching speed to fully utilize the peak discharging capacity or the peak feedback capacity of the power battery.

[0070] The first switching speed and the second switching speed can be preset. For example, the first switching speed can be 3 times of a preset switching speed, and the second switching speed can be 1 / 3 of the preset switching speed.

[0071] If the difference between the time when the working voltage of the power battery reaches the preset charging and discharging voltage threshold and the candidate end time is equal to zero, it indicates that the working voltage of the power battery reaches the preset charging and discharging voltage threshold at the candidate end time. At this time, the preset switching speed can be determined as the target switching speed, so that the peak discharging capacity or the peak feedback capacity of the power battery can be fully exerted while effectively reducing the risk of overcharging or overdischarging of the power battery.

[0072] An exemplary device In one exemplary embodiment of the present specification, a battery power switching control device is also provided, which comprises Figure 3 As shown in the figure, the device comprises: The first processing module 301 is configured to, in a case where the power battery operates in a first power state, determine a charging and discharging capacity prediction value of the power battery in the first power state according to a current detection value of the power battery in the first power state and a preset switching speed of the power battery switched from the first power state to a second power state; and the charging and discharging current limit value of the power battery in the first power state is greater than the charging and discharging current limit value in the second power state. The second processing module 302 is configured to, if the charging and discharging capacity prediction value represents a critical time when the power battery reaches the power state switching, determine a working voltage prediction value of the power battery in the power state switching process based on the preset switching speed. The third processing module 303 is configured to determine a target switching speed of the power battery in the power state switching process based on the size relationship between the working voltage prediction value and a preset charging and discharging voltage threshold of the power battery. The fourth processing module 304 is configured to control the power battery to be switched from the first power state to the second power state according to the target switching speed.

[0073] In one possible implementation, the second processing module 302 is specifically configured to: determine an open circuit voltage prediction value and a polarization voltage prediction value of the power battery at a target time based on the preset switching speed, and a current detection value and a state of charge detection value of the power battery at the critical time, the target time being any time in the power state switching process; determine a working voltage prediction value of the power battery at the target time based on the difference between the open circuit voltage prediction value and the polarization voltage prediction value.

[0074] In one possible implementation, the second processing module 302 is specifically configured to: determine a current prediction value of the power battery at each time point in the power state switching process based on the current detection value of the power battery at the critical time point and the preset switching speed; determine a state of charge prediction value of the power battery at the target time point based on the state of charge detection value and the current prediction value at each time point in the power state switching process; determine the open-circuit voltage prediction value and a polarization resistance prediction value of the power battery at the target time point based on the state of charge prediction value and a target correspondence relationship, the target correspondence relationship including a correspondence relationship between the state of charge of the power battery and the open-circuit voltage and the polarization resistance; determine the polarization voltage prediction value based on the current prediction value and the polarization resistance prediction value of the power battery at the target time point.

[0075] In one possible implementation, the first processing module 301 is specifically configured to: determine a current prediction value of the power battery at each time point in the power state switching process based on the current detection value of the power battery at the current time point and the preset switching speed; determine an actual charge and discharge capacity of the power battery in the first power state according to the current detection value of the power battery at each time point in the first power state, and determine a target reserved charge and discharge capacity in the power state switching process according to the current prediction value of the power battery at each time point in the power state switching process; determine a charge and discharge capacity prediction value of the power battery in the first power state according to a sum of the actual charge and discharge capacity and the target reserved charge and discharge capacity.

[0076] In one possible implementation, the second processing module 302 is specifically configured to: if the charge and discharge capacity prediction value is greater than or equal to a charge and discharge capacity threshold of the power battery in the first power state, determine that the critical time point is reached; if the charge and discharge capacity prediction value is less than the charge and discharge capacity threshold, determine that the critical time point is not reached.

[0077] In one possible implementation, the third processing module 303 is specifically configured to: determine a time when the working voltage of the power battery reaches the preset charging and discharging voltage threshold based on the working voltage prediction value and the preset charging and discharging voltage threshold of the power battery, and determine a candidate end time of the power state switching based on the preset switching speed; determine a target switching speed of the power battery in the power state switching process based on a time difference between the time when the working voltage of the power battery reaches the preset charging and discharging voltage threshold and the candidate end time.

[0078] In one possible implementation, the third processing module 303 is specifically configured to: if the time difference is less than zero, determine a first switching speed as the target switching speed, the first switching speed being higher than the preset switching speed; if the time difference is greater than zero, determine a second switching speed as the target switching speed, the second switching speed being lower than the preset switching speed; if the time difference is equal to zero, determine the preset switching speed as the target switching speed.

[0079] The battery power switching control device provided in the embodiment belongs to the same application concept as the battery power switching control method provided in the above embodiments of the present application, can execute the battery power switching control method provided in any of the above embodiments of the present application, and has the corresponding function modules and beneficial effects of executing the battery power switching control method. Technical details not described in detail in the embodiment can be referred to the specific processing content of the battery power switching control method provided in the above embodiments of the present application, which will not be described here.

[0080] Example battery management system In one example embodiment of the present specification, a battery management system is also provided, including a memory and at least one processor; wherein the memory is configured to store one or more computer instructions, wherein the one or more computer instructions are executed by the at least one processor to implement the battery power switching control method as described in any of the above embodiments.

[0081] Example vehicle In one example embodiment of the present specification, a vehicle is also provided, including a power battery and a battery management system as described in the above embodiments.

[0082] Example computer program product and storage medium In addition to the methods and apparatus described above, the battery power switching control method provided by the embodiments of the present disclosure can also be a computer program product, which includes computer program instructions that, when executed by a processor, cause the processor to perform the steps in the battery power switching control method according to various embodiments of the present disclosure described in the above “Exemplary Methods” section of the present disclosure.

[0083] The computer program product can be written in any combination of one or more programming languages, including an object-oriented programming language such as Java, C++, etc., and conventional procedural programming languages, such as the “C” programming language, or similar programming languages.

[0084] In addition, the embodiments of the present disclosure also provide a computer-readable storage medium having a computer program stored thereon, and the computer program causes a processor to execute the steps in the battery power switching control method according to various embodiments of the present disclosure described in the above “Exemplary Methods” section of the present disclosure.

[0085] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiments can be completed by a computer program instructing related hardware, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the above-mentioned embodiments. Any reference to memory, storage, databases, or other media in the embodiments provided by the present disclosure can include non-volatile and / or volatile memory. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. As an illustration but not limitation, RAM is available in many forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), Synchlink DRAM (SLDRAM), Rambus direct RAM (RDRAM), direct RAMbus dynamic RAM (DRDRAM), and Rambus dynamic RAM (RDRAM), etc.

[0086] Any technical features in the above embodiments can be combined, and for the sake of brevity, not all possible combinations are described above, however, as long as the combinations of technical features do not have contradictions, they shall be considered within the scope of the present disclosure.

[0087] The above embodiments only express several implementation manners of the present disclosure, and the description is relatively specific and detailed, but it shall not be understood as a limitation on the scope of the solutions provided by the embodiments of the present disclosure. It should be noted that, for those skilled in the art, several modifications and improvements can be made without departing from the concept of the present disclosure, and these shall be within the protection scope of the present disclosure. Therefore, the protection scope of the present disclosure shall be subject to the appended claims.

Claims

1. A battery power switching control method, characterized in that, include: When the power battery is operating in a first power state, the predicted charge and discharge capacity of the power battery in the first power state is determined based on the current detection value of the power battery in the first power state and the preset switching speed of the power battery switching from the first power state to the second power state; the charge and discharge current limit of the power battery in the first power state is greater than the charge and discharge current limit in the second power state. If the predicted charge / discharge capacity value represents the critical moment when the power battery reaches the power state switching, then based on the preset switching speed, the predicted operating voltage value of the power battery during the power state switching process is determined. Based on the relationship between the predicted operating voltage and the preset charge / discharge voltage threshold of the power battery, the target switching speed of the power battery during the power state switching process is determined. According to the target switching speed, the power battery is controlled to switch from the first power state to the second power state.

2. The method according to claim 1, characterized in that, Based on the preset switching speed, the predicted operating voltage of the power battery during the power state switching process is determined, including: Based on the preset switching speed, and the current detection value and state of charge detection value of the power battery at the critical moment, the predicted open-circuit voltage value and polarization voltage value of the power battery at the target moment are determined, where the target moment is any moment in the power state switching process. Based on the difference between the predicted open-circuit voltage and the predicted polarization voltage, the predicted operating voltage of the power battery at the target time is determined.

3. The method according to claim 2, characterized in that, Based on the preset switching speed, and the current detection value and state of charge detection value of the power battery at the critical moment, the predicted open-circuit voltage and polarization voltage values ​​of the power battery at the target moment are determined, including: Based on the current detection value of the power battery at the critical moment and the preset switching speed, the predicted current value of the power battery at each moment during the power state switching process is determined. Based on the detected state of charge value and the predicted current value at each moment during the power state switching process, the predicted state of charge value of the power battery at the target time is determined. Based on the predicted state of charge and the target correspondence, the predicted open-circuit voltage and the predicted polarization resistance of the power battery at the target time are determined. The target correspondence includes the correspondence between the state of charge of the power battery and the open-circuit voltage and polarization resistance. The polarization voltage prediction value is determined based on the predicted current value of the power battery at the target time and the predicted polarization resistance value.

4. The method according to claim 1, characterized in that, Based on the current detection value of the power battery in the first power state and the preset switching speed of the power battery switching from the first power state to the second power state, the predicted charge and discharge capacity value of the power battery in the first power state is determined, including: Based on the current detection value of the power battery at the current moment and the preset switching speed, the predicted current value of the power battery at each moment during the power state switching process is determined. Based on the current detection values ​​of the power battery at various times in the first power state, the actual charge and discharge capacity of the power battery in the first power state is determined, and based on the current prediction values ​​of the power battery at various times during the power state switching process, the target reserved charge and discharge capacity of the power battery during the power state switching process is determined. The predicted charge / discharge capacity of the power battery under the first power state is determined based on the sum of the actual charge / discharge capacity and the target reserved charge / discharge capacity.

5. The method according to claim 1, characterized in that, Determining whether the predicted charge / discharge capacity value represents the critical moment when the power battery reaches a power state switching condition includes: If the predicted charge / discharge capacity is greater than or equal to the charge / discharge capacity threshold of the power battery in the first power state, then it is determined that the critical moment has been reached. If the predicted charge / discharge capacity is less than the charge / discharge capacity threshold, it is determined that the critical moment has not been reached.

6. The method according to any one of claims 1 to 5, characterized in that, Based on the relationship between the predicted operating voltage and the preset charge / discharge voltage threshold of the power battery, the target switching speed of the power battery during the power state switching process is determined, including: Based on the relationship between the predicted operating voltage and the preset charge / discharge voltage threshold of the power battery, the time when the operating voltage of the power battery reaches the preset charge / discharge voltage threshold is determined, and based on the preset switching speed, a candidate end time for the power state switching is determined. The target switching speed of the power battery during the power state switching process is determined based on the time difference between the moment when the working voltage of the power battery reaches the preset charge / discharge voltage threshold and the candidate end time.

7. The method according to claim 6, characterized in that, The target switching speed of the power battery during the power state switching process is determined based on the difference between the time when the operating voltage of the power battery reaches the preset charge / discharge voltage threshold and the candidate end time, including: If the time difference is less than zero, the first switching speed is determined as the target switching speed, and the first switching speed is higher than the preset switching speed; If the time difference is greater than zero, the second switching speed is determined as the target switching speed, and the second switching speed is lower than the preset switching speed; If the time difference is zero, then the preset switching speed is determined as the target switching speed.

8. A battery power switching control device, characterized in that, include: The first processing module is configured to determine the predicted charge / discharge capacity of the power battery in the first power state based on the current detection value of the power battery in the first power state and a preset switching speed at which the power battery switches from the first power state to the second power state, when the power battery is operating in a first power state; the charge / discharge current limit of the power battery in the first power state is greater than the charge / discharge current limit in the second power state. The second processing module is used to determine the predicted operating voltage of the power battery during the power state switching process based on the preset switching speed if the predicted charge / discharge capacity value indicates that the power battery has reached the critical moment of power state switching. The third processing module is used to determine the target switching speed of the power battery during the power state switching process based on the relationship between the predicted working voltage value and the preset charge and discharge voltage threshold of the power battery. The fourth processing module is used to control the power battery to switch from the first power state to the second power state according to the target switching speed.

9. A battery management system, characterized in that, The method includes a memory and at least one processor; wherein the memory is used to store one or more computer instructions, wherein the one or more computer instructions are executed by the at least one processor to implement the battery power switching control method according to any one of claims 1 to 7.

10. A vehicle, characterized in that, It includes a power battery and a battery management system as described in claim 9.

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