Method for determining pre-undervoltage level, power control method, system, device and medium

Abstract

The present invention relates to a method for determining pre-undervoltage levels, a method for controlling pre-undervoltage power, a system, a device, and a medium. The method for determining pre-undervoltage levels includes: obtaining in real time the highest single-cell temperature, the lowest single-cell voltage, and the total assembly discharge current of the power battery of the vehicle; matching the highest single-cell temperature with the interval thresholds corresponding to each temperature usage interval to determine the temperature transition interval in which the power battery is currently located; determining the discharge cut-off voltage corresponding to the temperature transition interval according to the preset temperature threshold, the preset discharge cut-off voltage threshold, the preset temperature increment, and the preset highest single-cell temperature corresponding to the temperature usage interval in which the power battery is currently located; dividing the voltage threshold ranges corresponding to each pre-undervoltage level in the temperature transition interval according to the discharge cut-off voltage; and matching the lowest single-cell voltage and the total assembly discharge current with the voltage threshold ranges and current thresholds corresponding to each pre-undervoltage level respectively to determine the pre-undervoltage level in which the power battery is currently located, thereby solving the problem of power loss.

Description

Technical Field

[0001] The present invention relates to the technical field of intelligent control, and specifically relates to a method for determining pre-undervoltage levels, a power control method, a system, a device, and a medium. Background Art

[0002] At the end of discharging of an electric vehicle, factors such as SOC estimation deviation and unreasonable design of the maximum allowable discharge power may cause premature interruption of power. The pre-undervoltage power limit strategy is to limit the vehicle discharge power in advance through different pre-undervoltage levels without affecting the drivability and power performance of the vehicle, so as to avoid the problem of premature power interruption when the battery can discharge.

[0003] Generally, the pre-undervoltage power limit strategy is to perform power limit of different intensity levels in advance based on the cut-off voltage of each cell in different temperature ranges of the battery. A pre-undervoltage power control strategy for a power battery system is disclosed in the related art, including: obtaining the current temperature value of the power battery pack; obtaining the current SOC value of the power battery pack; obtaining all the cell voltage values in the power battery pack and determining the minimum cell voltage value of the power battery pack; obtaining the current allowable discharge power of the power battery pack according to the current temperature value and SOC value; determining whether the minimum cell voltage value is less than a preset pre-undervoltage threshold, and determining whether the duration of the minimum cell voltage value reaches a preset undervoltage protection time; when the minimum cell voltage value is less than the pre-undervoltage threshold and the duration of the minimum cell voltage value reaches the undervoltage protection time, reducing the allowable discharge power. However, when using this control strategy to control the pre-undervoltage power of the power battery system, there are the following defects: the cut-off voltage at the critical point in each temperature range will have a step jump. If the cell voltage is lower than the cut-off voltage of the cell after the jump, the allowable discharge power of the battery will be immediately limited to 0, resulting in power interruption and causing the problem of power loss during vehicle driving. Summary of the Invention

[0004] One of the purposes of the present invention is to provide a method for determining pre-undervoltage levels to solve the problem that when using the existing control strategy to control the pre-undervoltage power of the power battery system, the cut-off voltage at the critical point in each temperature range will have a step jump. If the cell voltage is lower than the cut-off voltage of the cell after the jump, the allowable discharge power of the battery will be immediately limited to 0, resulting in power interruption and causing the problem of power loss during vehicle driving; the second purpose is to provide a pre-undervoltage power control method; the third purpose is to provide a system for determining pre-undervoltage levels, the fourth purpose is to provide a pre-undervoltage power control system, the fifth purpose is to provide an electronic device, and the sixth purpose is to provide a computer-readable storage medium.

[0005] In order to achieve the above purposes, the technical solutions adopted by the present invention are as follows:

[0006] In an exemplary embodiment of the present application, the present application provides a method for determining a pre-undervoltage level, and the method for determining the pre-undervoltage level includes:

[0007] Obtain in real time the highest single-cell temperature, the lowest single-cell voltage, and the total assembly discharge current of the power battery of the vehicle;

[0008] Match the highest single-cell temperature with the interval thresholds corresponding to each temperature usage interval to determine the temperature transition interval in which the power battery is currently located;

[0009] According to the preset temperature threshold, the preset discharge cut-off voltage threshold, the preset temperature increment, and the preset highest single-cell temperature corresponding to the temperature usage interval in which the power battery is currently located, determine the discharge cut-off voltage corresponding to the temperature transition interval;

[0010] According to the discharge cut-off voltage, divide the voltage threshold ranges corresponding to each pre-undervoltage level in the temperature transition interval;

[0011] Match the lowest single-cell voltage and the total assembly discharge current with the voltage threshold ranges and current thresholds corresponding to each pre-undervoltage level respectively to determine the pre-undervoltage level in which the power battery is currently located.

[0012] In an exemplary embodiment of the present application, the linear interpolation method is used to determine the discharge cut-off voltage corresponding to the temperature transition interval.

[0013] In an exemplary embodiment of the present application, the present application provides a pre-undervoltage power control method, and the pre-undervoltage power control method includes:

[0014] Obtain in real time the highest single-cell temperature, the lowest single-cell voltage, and the total assembly discharge current of the power battery of the vehicle;

[0015] Match the highest single-cell temperature with the interval thresholds corresponding to each temperature usage interval to determine the temperature transition interval in which the power battery is currently located;

[0016] According to the preset temperature threshold, the preset discharge cut-off voltage threshold, the preset temperature increment, and the preset highest single-cell temperature corresponding to the temperature usage interval in which the power battery is currently located, determine the discharge cut-off voltage corresponding to the temperature transition interval;

[0017] According to the discharge cut-off voltage, divide the voltage threshold ranges corresponding to each pre-undervoltage level in the temperature transition interval;

[0018] Match the lowest single-cell voltage and the total assembly discharge current with the voltage threshold ranges and current thresholds corresponding to each pre-undervoltage level respectively to determine the pre-undervoltage level in which the power battery is currently located;

[0019] Control the discharge power of the power battery using a control strategy corresponding to the pre-undervoltage level.

[0020] In an exemplary embodiment of the present application, a linear interpolation method is used to determine the discharge cut-off voltage corresponding to the temperature transition interval.

[0021] In an exemplary embodiment of the present application, controlling the discharge power of the power battery using a control strategy corresponding to the pre-undervoltage level includes:

[0022] Obtain the current state of charge of the power battery of the vehicle;

[0023] Determine the discharge power corresponding to the power battery according to the state of charge and the highest single-cell temperature;

[0024] Determine the power control coefficient according to the pre-undervoltage level;

[0025] Based on the power control coefficient and the discharge power, determine the discharge power threshold;

[0026] Control the discharge power of the power battery according to the discharge power threshold.

[0027] In an exemplary embodiment of the present application, the present application provides a pre-undervoltage level determination system, and the pre-undervoltage level determination system includes:

[0028] An acquisition module configured to acquire in real time the highest single-cell temperature, the lowest single-cell voltage, and the total assembly discharge current of the power battery of the vehicle;

[0029] A temperature transition interval determination module configured to match the highest single-cell temperature with the interval thresholds corresponding to each temperature usage interval to determine the temperature transition interval in which the power battery is currently located;

[0030] A discharge cut-off voltage determination module configured to determine the discharge cut-off voltage corresponding to the temperature transition interval according to the preset temperature threshold, the preset discharge cut-off voltage threshold, the preset temperature increment, and the preset highest single-cell temperature corresponding to the current temperature usage interval of the power battery;

[0031] A voltage threshold range determination module configured to divide the voltage threshold ranges corresponding to each pre-undervoltage level in the temperature transition interval according to the discharge cut-off voltage;

[0032] A pre-undervoltage level determination module configured to match the lowest single-cell voltage and the total assembly discharge current with the voltage threshold ranges and current thresholds corresponding to each pre-undervoltage level respectively to determine the pre-undervoltage level in which the power battery is currently located.

[0033] In an exemplary embodiment of the present application, the present application provides a pre-undervoltage power control system, and the pre-undervoltage power control system includes:

[0034] An acquisition module, configured to acquire the highest single-cell temperature, the lowest single-cell voltage, and the total assembly discharge current of the power battery of the vehicle in real time;

[0035] A temperature transition interval determination module, configured to match the highest single-cell temperature with the interval thresholds corresponding to each temperature usage interval to determine the temperature transition interval in which the power battery is currently located;

[0036] A discharge cut-off voltage determination module, configured to determine the discharge cut-off voltage corresponding to the temperature transition interval according to the preset temperature threshold, the preset discharge cut-off voltage threshold, the preset temperature increment, and the preset highest single-cell temperature corresponding to the current temperature usage interval of the power battery;

[0037] A voltage threshold range determination module, configured to divide the voltage threshold ranges corresponding to each pre-undervoltage level in the temperature transition interval according to the discharge cut-off voltage;

[0038] A pre-undervoltage level determination module, configured to match the lowest single-cell voltage and the total assembly discharge current with the voltage threshold ranges and current thresholds corresponding to each pre-undervoltage level respectively to determine the pre-undervoltage level in which the power battery is currently located;

[0039] A control module, configured to control the discharge power of the power battery by using a control strategy corresponding to the pre-undervoltage level.

[0040] In an exemplary embodiment of the present application, the control module includes:

[0041] An acquisition unit, configured to acquire the current state of charge of the power battery of the vehicle;

[0042] A discharge power determination unit, configured to determine the discharge power corresponding to the power battery according to the state of charge and the highest single-cell temperature;

[0043] A power control coefficient determination unit, configured to determine a power control coefficient according to the pre-undervoltage level;

[0044] A discharge power threshold determination unit, configured to determine a discharge power threshold based on the power control coefficient and the discharge power;

[0045] A control unit, configured to control the discharge power of the power battery according to the discharge power threshold.

[0046] In an exemplary embodiment of the present application, the present application provides an electronic device, and the electronic device includes:

[0047] One or more processors;

[0048] A storage device for storing one or more programs, which, when executed by the one or more processors, cause the electronic device to implement the method as described above.

[0049] In an exemplary embodiment of the present application, the present application provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor of a computer, causes the computer to execute the method as described above.

[0050] Advantages of the present invention:

[0051] In the present application, by obtaining in real time the highest single-cell temperature, the lowest single-cell voltage, and the total assembly discharge current of the power battery of the vehicle, matching the highest single-cell temperature with the interval thresholds corresponding to each temperature usage interval to determine the temperature transition interval in which the power battery is currently located, and determining the discharge cut-off voltage corresponding to the temperature transition interval according to the preset temperature threshold, the preset discharge cut-off voltage threshold, the preset temperature increment, and the preset highest single-cell temperature corresponding to the temperature usage interval in which the power battery is currently located, dividing the voltage threshold range corresponding to each pre-undervoltage level in the temperature transition interval according to the discharge cut-off voltage, matching the lowest single-cell voltage and the total assembly discharge current with the voltage threshold range and the current threshold corresponding to each pre-undervoltage level respectively to determine the pre-undervoltage level in which the power battery is currently located, and controlling the pre-undervoltage power according to the pre-undervoltage level, the problem of power loss during vehicle driving can be solved. Description of the Drawings

[0052] The drawings herein are incorporated into the specification and form a part of the specification, showing embodiments consistent with the present application, and are used together with the specification to explain the principles of the present application. Obviously, the drawings in the following description are only some embodiments of the present application, and those of ordinary skill in the art can obtain other drawings based on these drawings without creative efforts. In the drawings:

[0053] Figure 1 Is a flowchart of a method for determining a pre-undervoltage level shown in an exemplary embodiment of the present application;

[0054] Figure 2 Is a flowchart of a method for controlling pre-undervoltage power shown in an exemplary embodiment of the present application;

[0055] Figure 3 Is Figure 2 A flowchart of an exemplary embodiment of controlling the discharge power of the power battery using a control strategy corresponding to the pre-undervoltage level in the shown embodiment;

[0056] Figure 4It is a relationship diagram between the minimum monomer voltage and the temperature of the power battery in a specific embodiment of the present application;

[0057] Figure 5 It is a block diagram of a pre-undervoltage level determination system shown in an exemplary embodiment of the present application;

[0058] Figure 6 It is a block diagram of a pre-undervoltage power control system shown in an exemplary embodiment of the present application;

[0059] Figure 7 It shows a schematic structural diagram of a computer system of an electronic device suitable for implementing the embodiments of the present application. Specific Embodiments

[0060] The following will describe the embodiments of the present invention with reference to the accompanying drawings and preferred embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be understood that the preferred embodiments are only for explaining the present invention and not for limiting the protection scope of the present invention.

[0061] It should be noted that the diagrams provided in the following embodiments only illustrate the basic concept of the present invention in a schematic manner. Therefore, only the components related to the present invention are shown in the diagrams, rather than being drawn according to the number, shape, and size of the components in actual implementation. The type, quantity, and ratio of each component in actual implementation can be arbitrarily changed, and the component layout type may also be more complex.

[0062] In the following description, a large number of details are explored to provide a more thorough explanation of the embodiments of the present invention. However, it is obvious to those skilled in the art that the embodiments of the present invention can be implemented without these specific details. In other embodiments, well-known structures and devices are shown in the form of block diagrams rather than in detail to avoid making the embodiments of the present invention difficult to understand.

[0063] Please refer to Figure 1 , Figure 1 It is a flowchart of a pre-undervoltage level determination method shown in an exemplary embodiment of the present application.

[0064] As Figure 1 shown, in an exemplary embodiment of the present application, the pre-undervoltage level determination method at least includes steps S110 to S150, which are introduced in detail as follows:

[0065] Step S110. Real-time obtain the highest monomer temperature, the lowest monomer voltage, and the total assembly discharge current of the power battery of the vehicle;

[0066] Step S120. Match the highest cell temperature with the interval thresholds corresponding to each temperature usage interval to determine the temperature transition interval in which the power battery is currently located;

[0067] Step S130. Determine the discharge cut-off voltage corresponding to the temperature transition interval according to the preset temperature threshold, preset discharge cut-off voltage threshold, preset temperature increment, and preset highest cell temperature corresponding to the temperature usage interval in which the power battery is currently located;

[0068] Specifically, according to the preset temperature threshold, preset discharge cut-off voltage threshold, preset temperature increment, and preset highest cell temperature corresponding to the temperature usage interval in which the power battery is currently located, use linear interpolation to determine the discharge cut-off voltage corresponding to the temperature transition interval;

[0069] Step S140. Divide the voltage threshold ranges corresponding to each pre-undervoltage level in the temperature transition interval according to the discharge cut-off voltage;

[0070] Step S150. Match the lowest cell voltage and the total discharge current with the voltage threshold ranges and current thresholds corresponding to each pre-undervoltage level to determine the pre-undervoltage level in which the power battery is currently located.

[0071] Please refer to Figure 2 , Figure 2 which is a flowchart of the pre-undervoltage power control method shown in an exemplary embodiment of the present application.

[0072] As Figure 2 shown, in an exemplary embodiment of the present application, the pre-undervoltage power control method at least includes steps S210 to S260, which are introduced in detail as follows:

[0073] Step S210. Obtain the highest cell temperature, the lowest cell voltage, and the total discharge current of the power battery of the vehicle in real time;

[0074] Step S220. Match the highest cell temperature with the interval thresholds corresponding to each temperature usage interval to determine the temperature transition interval in which the power battery is currently located;

[0075] Step S230. Determine the discharge cut-off voltage corresponding to the temperature transition interval according to the preset temperature threshold, preset discharge cut-off voltage threshold, preset temperature increment, and preset highest cell temperature corresponding to the temperature usage interval in which the power battery is currently located;

[0076] Specifically, according to the preset temperature threshold, preset discharge cut-off voltage threshold, preset temperature increment, and preset highest cell temperature corresponding to the temperature usage interval in which the power battery is currently located, use linear interpolation to determine the discharge cut-off voltage corresponding to the temperature transition interval;

[0077] Step S240. Divide the voltage threshold ranges corresponding to each pre-undervoltage level in the temperature transition interval according to the discharge cut-off voltage;

[0078] Step S250. Match the lowest cell voltage and the total assembly discharge current with the voltage threshold ranges and current thresholds corresponding to each pre-undervoltage level respectively to determine the current pre-undervoltage level of the power battery;

[0079] Step S260. Control the discharge power of the power battery by using the control strategy corresponding to the pre-undervoltage level.

[0080] Please refer to Figure 3 , Figure 3 is Figure 2 the flowchart of controlling the discharge power of the power battery by using the control strategy corresponding to the pre-undervoltage level in the embodiment shown.

[0081] As Figure 3 shown, in an exemplary embodiment of the present application, Figure 2 controlling the discharge power of the power battery by using the control strategy corresponding to the pre-undervoltage level in the embodiment shown includes steps S310 to S350, which are introduced in detail as follows:

[0082] Step S310. Obtain the current state of charge of the power battery of the vehicle;

[0083] Step S320. Determine the corresponding discharge power of the power battery according to the state of charge and the highest cell temperature;

[0084] Specifically, determine the corresponding discharge power of the power battery according to the state of charge, the highest cell temperature and the preset mapping relationship between the state of charge, the highest cell temperature and the discharge power;

[0085] Step S330. Determine the power control coefficient according to the pre-undervoltage level;

[0086] Specifically, determine the power control coefficient according to the pre-undervoltage level and the preset mapping relationship between the pre-undervoltage level and the power control coefficient;

[0087] Step S340. Determine the discharge power threshold based on the power control coefficient and the discharge power;

[0088] Specifically, the product of the power control coefficient and the discharge power is the discharge power threshold;

[0089] Step S350. Control the discharge power of the power battery according to the discharge power threshold;

[0090] In a specific embodiment, the steps of the pre-undervoltage power control method are as follows:

[0091] Obtain the highest single-cell temperature, the lowest single-cell voltage, and the total assembly discharge current of the vehicle's power battery in real time;

[0092] Match the highest single-cell temperature with the interval thresholds corresponding to each temperature usage interval to determine the temperature transition interval in which the power battery is currently located;

[0093] According to the preset temperature threshold, the preset discharge cut-off voltage threshold, the preset temperature increment, and the preset highest single-cell temperature corresponding to the temperature usage interval in which the power battery is currently located, use the linear interpolation method to determine the discharge cut-off voltage corresponding to the temperature transition interval;

[0094] According to the discharge cut-off voltage, divide the voltage threshold ranges corresponding to each pre-undervoltage level in the temperature transition interval;

[0095] Match the lowest single-cell voltage and the total assembly discharge current with the voltage threshold ranges and current thresholds corresponding to each pre-undervoltage level respectively to determine the pre-undervoltage level in which the power battery is currently located;

[0096] Control the discharge power of the power battery by using the control strategy corresponding to the pre-undervoltage level. The specific steps are as follows:

[0097] Obtain the current state of charge of the vehicle's power battery;

[0098] According to the state of charge, the highest single-cell temperature, and the preset mapping relationship between the state of charge, the highest single-cell temperature, and the discharge power, determine the discharge power corresponding to the power battery;

[0099] According to the pre-undervoltage level and the preset mapping relationship between the pre-undervoltage level and the power control coefficient, determine the power control coefficient;

[0100] Based on the power control coefficient and the discharge power, determine the discharge power threshold. Specifically, the product of the power control coefficient and the discharge power is the discharge power threshold;

[0101] Specifically, as shown in Table 1:

[0102] Table 1 Pre-undervoltage level table

[0103]

[0104]

[0105] In Table 1, n is the pre-undervoltage level and n is a natural number greater than 0, T max is the highest single-cell temperature of the vehicle's power battery collected by the temperature sensor, T1 and T2 are respectively the preset upper limit threshold and the preset lower limit threshold of the temperature usage interval of the power battery cell, Δ T is the preset temperature increment, and V1 is T max≥ The preset discharge cut-off voltage threshold corresponding to T1, V2 for T2 ≤ T max < The preset discharge cut-off voltage threshold corresponding to T1, V3 for T max < The single-cell discharge cut-off voltage threshold corresponding to T2; α n 、η n 、β n 、ε n 、γ n Are power limit coefficients corresponding to different pre-undervoltage levels n and different battery minimum temperature ranges, D n 、E n 、F n 、G n 、H n Are voltage thresholds corresponding to different pre-undervoltage levels n and different battery minimum temperature ranges, I 1n 、I 2n 、I 3n 、I 4n 、I 5n Is the maximum total battery current required to trigger the n-level pre-undervoltage for different battery minimum temperature ranges, t is the current holding duration required to trigger the n-level pre-undervoltage, D1 > D2 > D3 > … > D n And E1 > E2 > E3 > … > E n And F1 > F2 > F3 > … > F n And G1 > G2 > G3 > … > G n And H1 > H2 > H3 > … > H n ;

[0106] Specifically, during the vehicle discharge process, if T1 ≤ the highest single-cell temperature T of the power battery max < T1 + Δ T , as Figure 4 shown, according to the coordinate points (V2, T1) and (V1, T1 + Δ T ), the preset discharge cut-off voltage threshold V4 = V2 + (V1 - V2) * (T T - T1) / Δ max can be obtained within the temperature range [T1, T1 + Δ T , and V4 will change dynamically with the battery temperature T max during the discharge process;

[0107] If V4 + G2 < the lowest single-cell voltage V of the battery min ≤ V4 + G1 and the total battery discharge current I < I 41 for a duration of t, trigger the 1-level pre-undervoltage, and the current discharge power threshold is P 41 * η1, the discharge power P 41It is determined according to the state of charge, the highest single-cell temperature, and the preset mapping relationship between the state of charge, the highest single-cell temperature, and the discharge power. The power control coefficient η1 is determined according to the pre-undervoltage level and the preset mapping relationship between the pre-undervoltage level and the power control coefficient;

[0108] If V4 + G3 < the lowest single-cell voltage V of the battery min ≤ V4 + G2 and the discharge current I of the battery assembly < I 42 For a duration t, trigger the second-level pre-undervoltage, and the current discharge power threshold is P 42 *η2, the discharge power P 42 It is determined according to the state of charge, the highest single-cell temperature, and the preset mapping relationship between the state of charge, the highest single-cell temperature, and the discharge power. The power control coefficient η2 is determined according to the pre-undervoltage level and the preset mapping relationship between the pre-undervoltage level and the power control coefficient;

[0109] If V4 + G4 < the lowest single-cell voltage V of the battery min ≤ V4 + G3 and the discharge current I of the battery assembly < I 43 For a duration t, trigger the third-level undervoltage, and the current discharge power threshold is P 43 *η3, the discharge power P 43 It is determined according to the state of charge, the highest single-cell temperature, and the preset mapping relationship between the state of charge, the highest single-cell temperature, and the discharge power. The power control coefficient η3 is determined according to the pre-undervoltage level and the preset mapping relationship between the pre-undervoltage level and the power control coefficient;

[0110] If the lowest single-cell voltage V4 of the battery < V min ≤ V4 + G n and the discharge current I of the battery assembly < I 4n For a duration t, trigger the n-level pre-undervoltage, and the current discharge power threshold is P 4n *η n ,the discharge power P 4n It is determined according to the state of charge, the highest single-cell temperature, and the preset mapping relationship between the state of charge, the highest single-cell temperature, and the discharge power. The power control coefficient η n is determined according to the pre-undervoltage level and the preset mapping relationship between the pre-undervoltage level and the power control coefficient;

[0111] If the lowest single-cell voltage V of the battery min ≤ V4, trigger the single-cell discharge cut-off voltage, then the discharge power threshold of the battery is 0; During the vehicle discharge process, T2 ≤ the highest single-cell temperature T of the power battery max < T2 + Δ T ,the lowest single-cell voltage of the battery is V min ,the discharge current of the battery assembly is I;

[0112] As Figure 4 shown, based on the coordinate points (V3, T2) and (V2, T2 + Δ T ), through the linear interpolation formula, the cut-off discharge voltage V5 of the monomer within the temperature range [T2, T2 + Δ T can be obtained as V5 = V3 + (V2 - V3) * (T max - T2) / Δ T . During the discharge process, V5 will change dynamically with the change of the battery temperature T max .

[0113] If V5 + H2 < the minimum monomer voltage V min ≤ V5 + H1 and the discharge current I of the battery assembly < I 51 for a duration of t, a level 1 pre-undervoltage is triggered, and the current discharge power is limited to P 51 * η1. The discharge power P 51 is determined according to the preset mapping relationship between the state of charge, the highest monomer temperature, and the state of charge, the highest monomer temperature and the discharge power. The power control coefficient η1 is determined according to the preset mapping relationship between the pre-undervoltage level and the power control coefficient;

[0114] If V5 + H3 < the minimum monomer voltage V min ≤ V5 + H2 and the discharge current I of the battery assembly < I 52 for a duration of t, a level 2 pre-undervoltage is triggered, and the current discharge power is limited to P 52 * η2. The discharge power P 52 is determined according to the preset mapping relationship between the state of charge, the highest monomer temperature, and the state of charge, the highest monomer temperature and the discharge power. The power control coefficient η2 is determined according to the preset mapping relationship between the pre-undervoltage level and the power control coefficient;

[0115] If V5 + H4 < the minimum monomer voltage V min ≤ V5 + H3 and the discharge current I of the battery assembly < I 53 for a duration of t, a level 3 undervoltage is triggered, and the current discharge power is limited to P 53 * η3. The discharge power P 53 is determined according to the preset mapping relationship between the state of charge, the highest monomer temperature, and the state of charge, the highest monomer temperature and the discharge power. The power control coefficient η3 is determined according to the preset mapping relationship between the pre-undervoltage level and the power control coefficient;

[0116] If the minimum monomer voltage V5 < V min ≤ V5 + H n and the discharge current I of the battery assembly < I 5n for a duration of t, an n-level pre-undervoltage is triggered, and the current discharge power is limited to P5n *η n The discharge power P 5n is determined according to the state of charge, the highest single-cell temperature, and the preset mapping relationship between the state of charge, the highest single-cell temperature, and the discharge power. The power control coefficient η n is determined according to the pre-undervoltage level and the preset mapping relationship between the pre-undervoltage level and the power control coefficient;

[0117] If the lowest single-cell voltage V of the battery min ≤V5, triggering the single-cell discharge cut-off voltage, the discharge power threshold of the battery is 0;

[0118] As Figure 4 shown, when using the pre-undervoltage power control method of the present application to control the pre-undervoltage power of the power battery, during the discharge process, when the highest single-cell temperature T of the power battery max reaches T2, the single-cell lower limit cut-off voltage will no longer directly jump from V3 to V2, but as the battery temperature T2 rises to T2+Δ T in the process, the single-cell lower limit cut-off voltage linearly transitions from V3 to V2 to avoid power interruption caused by the jump of the single-cell lower limit cut-off voltage; similarly, during the discharge process, if the highest single-cell temperature T of the power battery max reaches T1, the single-cell lower limit cut-off voltage will no longer directly jump from V2 to V1, but as the battery temperature T1 rises to T1+Δ T in the process, the single-cell lower limit cut-off voltage linearly transitions from V2 to V1;

[0119] Control the discharge power of the power battery according to the discharge power threshold;

[0120] Please refer to Figure 5 , Figure 5 which is a block diagram of the pre-undervoltage level determination system shown in an exemplary embodiment of the present application.

[0121] As Figure 5 shown, in an exemplary embodiment of the present application, the pre-undervoltage level determination system M500 includes:

[0122] An acquisition module M510, configured to acquire the highest single-cell temperature, the lowest single-cell voltage, and the total assembly discharge current of the power battery of the vehicle in real time;

[0123] A temperature transition interval determination module M520, configured to match the highest single-cell temperature with the interval threshold corresponding to each temperature usage interval to determine the temperature transition interval where the power battery is currently located;

[0124] The discharge cut-off voltage determination module M530 is configured to determine the discharge cut-off voltage corresponding to the temperature transition range according to the preset temperature threshold, the preset discharge cut-off voltage threshold, the preset temperature increment, and the preset maximum single cell temperature corresponding to the current temperature range of the power battery.

[0125] The voltage threshold range determination module M540 is configured to divide the voltage threshold ranges corresponding to each pre-undervoltage level in the temperature transition range according to the discharge cut-off voltage.

[0126] The pre-undervoltage level determination module M550 is configured to match the lowest single cell voltage and the total assembly discharge current with the voltage threshold ranges and current thresholds corresponding to each pre-undervoltage level respectively, to determine the current pre-undervoltage level of the power battery.

[0127] Please refer to Figure 6 , Figure 6 which is a block diagram of the pre-undervoltage power control system shown in an exemplary embodiment of the present application.

[0128] As Figure 6 shown, in an exemplary embodiment of the present application, the pre-undervoltage power control system M600 includes:

[0129] The acquisition module M610 is configured to acquire the maximum single cell temperature, the lowest single cell voltage, and the total assembly discharge current of the power battery of the vehicle in real time.

[0130] The temperature transition range determination module M620 is configured to match the maximum single cell temperature with the interval thresholds corresponding to each temperature range of use, to determine the current temperature transition range of the power battery.

[0131] The discharge cut-off voltage determination module M630 is configured to determine the discharge cut-off voltage corresponding to the temperature transition range according to the preset temperature threshold, the preset discharge cut-off voltage threshold, the preset temperature increment, and the preset maximum single cell temperature corresponding to the current temperature range of use of the power battery.

[0132] The voltage threshold range determination module M640 is configured to divide the voltage threshold ranges corresponding to each pre-undervoltage level in the temperature transition range according to the discharge cut-off voltage.

[0133] The pre-undervoltage level determination module M650 is configured to match the lowest single cell voltage and the total assembly discharge current with the voltage threshold ranges and current thresholds corresponding to each pre-undervoltage level respectively, to determine the current pre-undervoltage level of the power battery;

[0134] The control module M660 is configured to control the discharge power of the power battery by using the control strategy corresponding to the pre-undervoltage level.

[0135] In an exemplary embodiment of the present application, the control module includes:

[0136] An acquisition unit configured to acquire the current state of charge of the power battery of the vehicle;

[0137] A discharge power and power control coefficient determination unit configured to determine the discharge power corresponding to the power battery according to the state of charge and the highest single cell temperature;

[0138] A power control coefficient determination unit configured to determine the power control coefficient according to the pre-undervoltage level;

[0139] A discharge power threshold determination unit configured to determine the discharge power threshold based on the power control coefficient and the discharge power;

[0140] A control unit configured to control the discharge power of the power battery according to the discharge power threshold.

[0141] It should be noted that the pre-undervoltage level determination system provided in the above embodiment and the pre-undervoltage level determination method provided in the above embodiment belong to the same concept. The pre-undervoltage power control system provided in the above embodiment and the pre-undervoltage power control method provided in the above embodiment belong to the same concept. The specific manners in which each module and unit perform operations have been described in detail in the method embodiment and will not be elaborated here. In practical applications, the pre-undervoltage level determination system and the pre-undervoltage power control system provided in the above embodiments can, as needed, allocate the above functions to different functional modules, that is, divide the internal structure of the device into different functional modules to complete all or part of the functions described above, and this is not limited here either.

[0142] An embodiment of the present application further provides an electronic device, including: one or more processors; a storage device for storing one or more programs, and when the one or more programs are executed by the one or more processors, the electronic device implements the pre-undervoltage level determination method and the pre-undervoltage power control method provided in each of the above embodiments.

[0143] Figure 7 The structure diagram of a computer system of an electronic device suitable for implementing the embodiments of the present application is shown. It should be noted that Figure 7 The computer system 700 of the electronic device shown is only an example and should not impose any limitations on the functions and usage scope of the embodiments of the present application.

[0144] Such as Figure 7As shown, the computer system 700 includes a Central Processing Unit (CPU) 701, which can perform various appropriate actions and processes according to the program stored in the Read-Only Memory (ROM) 702 or the program loaded from the storage section 708 into the Random Access Memory (RAM) 703, such as executing the methods described in the above embodiments. In the RAM 703, various programs and data required for system operation are also stored. The CPU 701, ROM 702, and RAM 703 are connected to each other via a bus 704. An Input / Output (I / O) interface 705 is also connected to the bus 704.

[0145] The following components are connected to the I / O interface 705: an input section 706 including a keyboard, a mouse, etc.; an output section 707 including, for example, a Cathode Ray Tube (CRT), a Liquid Crystal Display (LCD), etc., and a speaker, etc.; a storage section 708 including a hard disk, etc.; and a communication section 709 including a network interface card such as a LAN (Local Area Network) card, a modem, etc. The communication section 709 performs communication processing via a network such as the Internet. A drive 710 is also connected to the I / O interface 705 as needed. A removable medium 711, such as a magnetic disk, an optical disk, a magneto-optical disk, a semiconductor memory, etc., is installed on the drive 710 as needed so that a computer program read from it can be installed into the storage section 708 as needed.

[0146] Specifically, according to the embodiments of the present application, the processes described above with reference to the flowcharts can be implemented as computer software programs. For example, the embodiments of the present application include a computer program product, which includes a computer program carried on a computer-readable medium, and the computer program contains a computer program for executing the methods shown in the flowcharts. In such an embodiment, the computer program can be downloaded and installed from the network via the communication section 709, and / or installed from the removable medium 711. When the computer program is executed by the Central Processing Unit (CPU) 701, various functions defined in the system of the present application are executed.

[0147] It should be noted that the computer-readable medium shown in the embodiments of the present application can be a computer-readable signal medium, a computer-readable storage medium, or any combination of the two. A computer-readable storage medium can be, for example, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination of the above. More specific examples of the computer-readable storage medium may include, but are not limited to: an electrical connection with one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM), a flash memory, an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In the present application, a computer-readable signal medium can include a data signal propagated in a baseband or as part of a carrier wave, which carries a computer-readable computer program. Such a propagated data signal can take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination of the above. A computer-readable signal medium can also be any computer-readable medium other than a computer-readable storage medium, which can send, propagate, or transmit a program for use by or in connection with an instruction execution system, apparatus, or device. The computer program contained on the computer-readable medium can be transmitted using any appropriate medium, including but not limited to: wireless, wired, etc., or any suitable combination of the above.

[0148] The flowcharts and block diagrams in the accompanying drawings illustrate the possible architectures, functions, and operations of systems, methods, and computer program products according to various embodiments of the present application. Among them, each block in the flowchart or block diagram can represent a module, a program segment, or a part of code, and the above module, program segment, or part of code contains one or more executable instructions for implementing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the blocks may occur in a different order than marked in the accompanying drawings. For example, two consecutive blocks shown may actually be executed substantially in parallel, and they may sometimes be executed in the reverse order, depending on the functions involved. It should also be noted that each block in the block diagram or flowchart, and the combination of blocks in the block diagram or flowchart, can be implemented by a dedicated hardware-based system for performing the specified functions or operations, or can be implemented by a combination of dedicated hardware and computer instructions.

[0149] The units involved in the embodiments described in this application can be implemented in software or in hardware, and the described units can also be provided in a processor. Among them, the names of these units do not, in some cases, constitute a limitation on the unit itself.

[0150] Another aspect of this application also provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor of a computer, the computer is caused to execute the pre-undervoltage level determination method and the pre-undervoltage power control method as described above. The computer-readable storage medium can be included in the electronic device described in the above embodiments, or can exist alone without being assembled into the electronic device.

[0151] Another aspect of this application also provides a computer program product or a computer program. The computer program product or the computer program includes computer instructions, and the computer instructions are stored in a computer-readable storage medium. A processor of a computer device reads the computer instructions from the computer-readable storage medium, and the processor executes the computer instructions, so that the computer device executes the pre-undervoltage level determination method and the pre-undervoltage power control method provided in the above various embodiments.

[0152] The above embodiments only exemplarily illustrate the principles and effects of the present invention, rather than limiting the present invention. Any person familiar with this technology can modify or change the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes made by those with ordinary knowledge in the technical field without departing from the spirit and technical idea disclosed by the present invention should still be covered by the claims of the present invention.

[0153] The above embodiments only exemplarily illustrate the principles and effects of the present invention, rather than limiting the present invention. Any person familiar with this technology can modify or change the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes made by those with ordinary knowledge in the technical field without departing from the spirit and technical idea disclosed by the present invention should still be covered by the claims of the present invention.

Claims

1. A method for determining the pre-undervoltage level, characterized in that The method for determining the pre-undervoltage level includes: Obtaining in real time the highest single-cell temperature, the lowest single-cell voltage, and the total assembly discharge current of the power battery of the vehicle; Matching the highest single-cell temperature with the interval thresholds corresponding to each temperature usage interval to determine the temperature transition interval in which the power battery is currently located; Determining the discharge cut-off voltage corresponding to the temperature transition interval according to the preset temperature threshold, the preset discharge cut-off voltage threshold, the preset temperature increment, and the preset highest single-cell temperature corresponding to the temperature usage interval in which the power battery is currently located; Dividing the voltage threshold ranges corresponding to each pre-undervoltage level in the temperature transition interval according to the discharge cut-off voltage; Matching the lowest single-cell voltage and the total assembly discharge current with the voltage threshold ranges and current thresholds corresponding to each pre-undervoltage level respectively to determine the pre-undervoltage level in which the power battery is currently located.

2. The method for determining the pre-undervoltage level according to claim 1, wherein Using the linear interpolation method to determine the discharge cut-off voltage corresponding to the temperature transition interval.

3. A pre-undervoltage power control method, characterized in that The pre-undervoltage power control method includes: Obtaining in real time the highest single-cell temperature, the lowest single-cell voltage, and the total assembly discharge current of the power battery of the vehicle; Matching the highest single-cell temperature with the interval thresholds corresponding to each temperature usage interval to determine the temperature transition interval in which the power battery is currently located; Determining the discharge cut-off voltage corresponding to the temperature transition interval according to the preset temperature threshold, the preset discharge cut-off voltage threshold, the preset temperature increment, and the preset highest single-cell temperature corresponding to the temperature usage interval in which the power battery is currently located; Dividing the voltage threshold ranges corresponding to each pre-undervoltage level in the temperature transition interval according to the discharge cut-off voltage; Matching the lowest single-cell voltage and the total assembly discharge current with the voltage threshold ranges and current thresholds corresponding to each pre-undervoltage level respectively to determine the pre-undervoltage level in which the power battery is currently located; Controlling the discharge power of the power battery by using the control strategy corresponding to the pre-undervoltage level.

4. The pre-undervoltage power control method according to claim 3, characterized in that, Using the linear interpolation method to determine the discharge cut-off voltage corresponding to the temperature transition interval.

5. The pre-undervoltage power control method according to claim 3, wherein Controlling the discharge power of the power battery by using the control strategy corresponding to the pre-undervoltage level includes: Obtaining the current state of charge of the power battery of the vehicle; Determining the discharge power corresponding to the power battery according to the state of charge and the highest single-cell temperature; Determining the power control coefficient according to the pre-undervoltage level; Determining the discharge power threshold based on the power control coefficient and the discharge power; Controlling the discharge power of the power battery according to the discharge power threshold.

6. A pre-undervoltage level determination system, characterized in that The system for determining the pre-undervoltage level includes: An acquisition module configured to obtain in real time the highest single-cell temperature, the lowest single-cell voltage, and the total assembly discharge current of the power battery of the vehicle; A temperature transition interval determination module configured to match the highest single-cell temperature with the interval thresholds corresponding to each temperature usage interval to determine the temperature transition interval in which the power battery is currently located; A discharge cut-off voltage determination module configured to determine the discharge cut-off voltage corresponding to the temperature transition interval according to the preset temperature threshold, the preset discharge cut-off voltage threshold, the preset temperature increment, and the preset highest single-cell temperature corresponding to the temperature usage interval in which the power battery is currently located; A voltage threshold range determination module, configured to divide the voltage threshold ranges corresponding to each pre-undervoltage level in the temperature transition interval according to the discharge cut-off voltage; A pre-undervoltage level determination module, configured to match the lowest single-cell voltage and the total assembly discharge current with the voltage threshold ranges and current thresholds corresponding to each pre-undervoltage level respectively, and determine the pre-undervoltage level where the power battery is currently located.

7. A pre-undervoltage power control system, characterized in that, The pre-undervoltage power control system includes: An acquisition module, configured to acquire the highest single-cell temperature, the lowest single-cell voltage, and the total assembly discharge current of the power battery of the vehicle in real time; A temperature transition interval determination module, configured to match the highest single-cell temperature with the interval thresholds corresponding to each temperature usage interval, and determine the temperature transition interval where the power battery is currently located; A discharge cut-off voltage determination module, configured to determine the discharge cut-off voltage corresponding to the temperature transition interval according to the preset temperature threshold, the preset discharge cut-off voltage threshold, the preset temperature increment, and the preset highest single-cell temperature corresponding to the current temperature usage interval of the power battery; A voltage threshold range determination module, configured to divide the voltage threshold ranges corresponding to each pre-undervoltage level in the temperature transition interval according to the discharge cut-off voltage; A pre-undervoltage level determination module, configured to match the lowest single-cell voltage and the total assembly discharge current with the voltage threshold ranges and current thresholds corresponding to each pre-undervoltage level respectively, and determine the pre-undervoltage level where the power battery is currently located; A control module, configured to control the discharge power of the power battery by using a control strategy corresponding to the pre-undervoltage level.

8. The pre-undervoltage power control system according to claim 7, characterized in that The control module includes: An acquisition unit, configured to acquire the current state of charge of the power battery of the vehicle; A discharge power determination unit, configured to determine the discharge power corresponding to the power battery according to the state of charge and the highest single-cell temperature; A power control coefficient determination unit, configured to determine a power control coefficient according to the pre-undervoltage level; A discharge power threshold determination unit, configured to determine a discharge power threshold based on the power control coefficient and the discharge power; A control unit, configured to control the discharge power of the power battery according to the discharge power threshold.

9. An electronic device, characterized in that, The electronic device includes: One or more processors; A storage device for storing one or more programs, which, when executed by the one or more processors, cause the electronic device to implement the method according to any one of claims 1-5.

10. A computer-readable storage medium, characterized in that, A computer program is stored thereon, which, when executed by a processor of the computer, causes the computer to execute the method according to any one of claims 1-5.

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