Overvoltage protection method, battery management system and vehicle

Abstract

The embodiment of the present application provides an overvoltage protection method, a battery management system and a vehicle, the method comprising: performing overvoltage protection when the voltage of the battery is greater than a voltage threshold; lowering the voltage threshold in response to the overvoltage protection duration being greater than a preset duration. By adopting the above scheme, the voltage threshold can be adjusted in a targeted manner according to the data in the process of adjusting the voltage overvoltage, and a suitable voltage threshold can be determined, thereby improving the battery performance while reducing the error fault rate.

Description

Technical Field

[0001] The present application relates to but is not limited to the field of battery technology, and in particular to an overvoltage protection method, a battery management system and a vehicle. Background Art

[0002] With the replenishment of electric vehicles, the safety and service life of power batteries are becoming more and more concerned, especially the large-scale use of lithium batteries. Due to the characteristics of lithium batteries themselves, the normal use range is strictly limited. Exceeding the voltage range, temperature range, and current range will seriously damage the lithium battery. Therefore, the control system of the power battery needs to monitor the battery information and safety at all times to protect the battery.

[0003] The currently commonly used power battery cell voltage protection is generally achieved by monitoring the battery cell voltage and comparing it with a set threshold. When the overvoltage protection threshold is reached, the cell overvoltage protection strategy is activated.

[0004] However, an unreasonable overvoltage protection threshold will trigger the overvoltage protection mechanism in advance, thereby reducing the battery's available power and causing a high error failure rate. Summary of the invention

[0005] The embodiments of the present application hope to provide an overvoltage protection method, a battery management system and a vehicle, which can improve battery performance while reducing the error failure rate.

[0006] The technical solution of this application is implemented as follows:

[0007] The present application provides an overvoltage protection method, including:

[0008] When the battery voltage is greater than the voltage threshold, overvoltage protection is performed;

[0009] In response to the overvoltage protection duration being greater than a preset duration, the voltage threshold is lowered.

[0010] It is understandable that when the battery voltage obtained by the vehicle is greater than the voltage threshold, the vehicle performs voltage overvoltage protection processing and determines the overvoltage protection duration for adjusting the voltage overvoltage. If the overvoltage protection duration is greater than the preset duration, it means that the voltage threshold at this time is set unreasonably, that is, the voltage threshold is too high, resulting in excessive protection of the battery voltage and limiting battery performance. Therefore, the voltage threshold is adjusted in the process of adjusting the voltage overvoltage. In this process, the voltage threshold is not directly lowered at the beginning when the battery voltage is greater than the voltage threshold. Instead, in the process of performing voltage overvoltage protection, it is judged whether to adjust the voltage threshold based on the overvoltage protection duration and the preset duration. This can avoid setting the voltage threshold too low and causing a high error failure rate. According to the data in the process of adjusting the voltage overvoltage, the voltage threshold is adjusted in a targeted manner to determine the appropriate voltage threshold, thereby improving battery performance while reducing the error failure rate.

[0011] In the above solution, in response to the overvoltage protection duration being greater than the preset duration, before lowering the voltage threshold, the overvoltage protection method further includes: determining the overvoltage protection duration.

[0012] It can be understood that when the battery voltage obtained by the vehicle is greater than the voltage threshold, the vehicle performs voltage overvoltage protection processing to determine the overvoltage protection duration of the adjusted voltage overvoltage, thereby judging whether it exceeds the preset duration, and then determining whether to adjust the preset voltage threshold. This can avoid setting the preset voltage threshold too low, resulting in a high error fault rate. By making targeted adjustments to the preset voltage threshold based on the data in the process of adjusting the voltage overvoltage, a suitable preset voltage threshold can be determined, thereby improving battery performance while reducing the error fault rate.

[0013] In the above scheme, the overvoltage protection duration includes: the current withdrawal duration of the charging pile, which represents the time taken for the charging pile to start the current withdrawal operation and for the current value of the charging pile to become zero;

[0014] Determine the overvoltage protection duration, including:

[0015] When the voltage is greater than the voltage threshold, overvoltage protection is performed to determine the current withdrawal time.

[0016] In the above scheme, the overvoltage protection duration includes: the total overlimit duration; the total overlimit duration represents the total duration of the battery voltage returning to the voltage threshold after exceeding the voltage threshold;

[0017] Determine the overvoltage protection duration, including:

[0018] When the voltage is greater than the voltage threshold, overvoltage protection is performed to determine the overlimit duration; the overlimit duration represents the time it takes for the battery voltage to return to the voltage threshold after it exceeds the voltage threshold for the last time;

[0019] Based on the overrun duration, the total overrun duration is determined.

[0020] In the above scheme, the overvoltage protection duration includes: the current withdrawal duration of the charging pile and the total over-limit duration;

[0021] Determine the overvoltage protection duration, including:

[0022] When the battery voltage is greater than the voltage threshold, overvoltage protection is performed to determine the current withdrawal time and the over-limit time;

[0023] Based on the overrun duration, the total overrun duration is determined.

[0024] It can be understood that when the obtained battery voltage is greater than the voltage threshold, the vehicle performs voltage overvoltage protection processing to determine the current withdrawal time, or, when the obtained battery voltage is greater than the voltage threshold, the vehicle performs voltage overvoltage protection processing to determine the over-limit time; and performs calculations based on the over-limit time to determine the total over-limit time, or, when the obtained battery voltage is greater than the voltage threshold, the vehicle performs voltage overvoltage protection processing to determine the current withdrawal time and the over-limit time; and determines the total over-limit time based on the over-limit time. The overvoltage protection time is determined in three ways, which enriches the overvoltage protection time determination method and thus enriches the diversity of voltage threshold adjustment.

[0025] In the above scheme, the total duration of the overrun is determined based on the duration of the overrun, including:

[0026] Obtain the historical over-limit duration of the battery voltage; the historical over-limit duration is the over-limit duration corresponding to each of the over-limit times that the battery voltage has historically exceeded the voltage threshold;

[0027] Determine the total duration of the overlimit; the total duration of the overlimit is the sum of the overlimit duration and the historical overlimit duration.

[0028] It can be understood that the vehicle obtains the historical over-limit duration of the battery voltage and determines the total over-limit duration through the historical over-limit duration, so as to facilitate the subsequent comparison of the total over-limit duration with the preset duration to determine the life of the battery cells and whether to adjust the voltage threshold according to the battery life.

[0029] In the above solution, in response to the overvoltage protection duration being greater than the preset duration, lowering the voltage threshold comprises:

[0030] If the overvoltage protection duration is greater than the preset duration, a voltage deviation value is determined during the overvoltage protection process; and based on the voltage deviation value, the voltage threshold is lowered.

[0031] It can be understood that when the overvoltage protection duration is greater than the preset duration, determining the voltage deviation value during the process of adjusting the voltage overvoltage can accurately determine the accuracy of the voltage to be adjusted, so that the voltage threshold can be adjusted subsequently through the voltage deviation value.

[0032] In the above scheme, if the overvoltage protection duration is greater than the preset duration, the voltage deviation value is determined during the overvoltage protection process, including:

[0033] If the overvoltage protection duration is greater than the preset duration, the voltage deviation value is determined based on the voltage value corresponding to the excessive duration during the overvoltage protection process.

[0034] It is understandable that when the overvoltage protection duration is greater than the preset duration, in the process of adjusting the voltage overvoltage, the voltage deviation value is determined based on the excess duration, so that the accuracy of the voltage to be adjusted can be accurately determined.

[0035] In the above scheme, the preset duration includes: the limit duration; the limit duration represents the normal duration from when the charging pile starts to perform the current reduction operation to when the current value of the charging pile becomes zero;

[0036] If the overvoltage protection duration is greater than the preset duration, the voltage deviation value is determined based on the voltage value corresponding to the overlimit duration during the overvoltage protection process, including:

[0037] When the current reduction time in the overvoltage protection time is greater than the limit time, the voltage deviation value is determined based on the voltage value corresponding to the excess time.

[0038] In the above scheme, the preset duration includes: the over-limit duration; the over-limit duration represents the duration of the battery voltage response battery life;

[0039] If the overvoltage protection duration is greater than the preset duration, the voltage deviation value is determined based on the voltage value corresponding to the overlimit duration during the overvoltage protection process, including:

[0040] When the total over-limit duration in the overvoltage protection duration is greater than the over-limit limit duration, the voltage deviation value is determined based on the voltage value corresponding to the over-limit duration.

[0041] In the above scheme, the preset duration includes: the limit duration and the over-limit limit duration;

[0042] If the overvoltage protection duration is greater than the preset duration, the voltage deviation value is determined based on the voltage value corresponding to the overlimit duration during the overvoltage protection process, including:

[0043] When the current withdrawal time is greater than the limit time, and the total exceeding time is greater than the exceeding limit time, the voltage deviation value is determined based on the voltage value corresponding to the exceeding time.

[0044] It can be understood that when the vehicle's current withdrawal time in the overvoltage protection time is greater than the limit time, the voltage deviation value is determined based on the excess time; or, when the total excess time in the overvoltage protection time is greater than the excess limit time, the voltage deviation value is determined based on the excess time; or, when the current withdrawal time is greater than the limit time and the total excess time is greater than the excess limit time, the voltage deviation value is determined based on the excess time. Calculating the voltage deviation value according to the excess time based on at least one of the three situations can facilitate subsequent adjustment of the voltage threshold to obtain the target voltage threshold, making the target voltage threshold more accurate, thereby reducing the error reporting failure rate.

[0045] In the above scheme, when the voltage of the battery is greater than the voltage threshold, overvoltage protection is performed to determine the current withdrawal time and the overlimit time; after determining the total overlimit time based on the overlimit time, the overvoltage protection method further includes:

[0046] If the total exceeding time is less than or equal to the exceeding limit time, then when the current withdrawal time is greater than the limit time, the voltage deviation value is determined based on the voltage value corresponding to the exceeding time.

[0047] It can be understood that if the total exceeding time is less than or equal to the exceeding limit time, then when the retreat current time is greater than the limit time, the voltage deviation value is determined based on the exceeding time. The entire process of determining the voltage deviation value is determined based on the data in the overvoltage protection processing process, so that the determined voltage deviation value is more targeted, and then the voltage threshold is adjusted based on the voltage deviation value to obtain the target voltage threshold, so that the target voltage threshold is more accurate, thereby reducing the error failure rate.

[0048] In the above scheme, the voltage value corresponding to the excessive time duration is the first voltage value corresponding to each time duration node within the excessive time duration;

[0049] Based on the voltage value corresponding to the over-limit time, the voltage deviation value is determined, including:

[0050] Determine a second voltage value corresponding to each duration node within the exceeded duration; the second voltage value is the difference between the first voltage value and the voltage threshold;

[0051] Determine the total voltage value of the overrun time; the total voltage value is the sum of the second voltage values ​​corresponding to each time node;

[0052] Determine a voltage deviation value; the voltage deviation value is the ratio of the total voltage value to the overlimit duration; in response to the overvoltage protection duration being greater than the preset duration, lower the voltage threshold to obtain a target voltage threshold that is the difference between the voltage threshold and the voltage deviation value.

[0053] It can be understood that the vehicle determines the first voltage value corresponding to each time node within the excess time based on the excess time; determines the second voltage value corresponding to each time node based on the voltage threshold and the voltage value; performs a sum operation on the second voltage values ​​to determine the total voltage value of the excess time; and performs a quotient operation based on the total voltage value and the excess time to determine the voltage deviation value. The entire process of determining the voltage deviation value is determined based on the data in the voltage overvoltage protection processing process, so that the determined voltage deviation value is more targeted, and then the voltage threshold is adjusted based on the voltage deviation value to obtain the target voltage threshold, so that the target voltage threshold is more accurate, thereby reducing the error fault rate.

[0054] The present application provides a battery management system, including:

[0055] The controller is used to perform overvoltage protection when the voltage of the battery is greater than a voltage threshold; in response to the overvoltage protection duration being greater than a preset duration, the voltage threshold is lowered.

[0056] An embodiment of the present application provides a vehicle, including: a battery management system and a battery.

[0057] The embodiment of the present application provides an overvoltage protection method, a battery management system and a vehicle. The overvoltage protection method includes: when the voltage of the battery obtained is greater than the voltage threshold, voltage overvoltage protection processing is performed to determine the overvoltage protection duration for adjusting the voltage overvoltage; if the overvoltage protection duration is greater than the preset duration, the voltage threshold is adjusted to determine the target voltage threshold. Using the above scheme, when the voltage of the battery obtained by the vehicle is greater than the voltage threshold, voltage overvoltage protection processing is performed to determine the overvoltage protection duration for adjusting the voltage overvoltage. If the overvoltage protection duration is greater than the preset duration, it means that the voltage threshold at this time is set unreasonably, that is, the voltage threshold is too high, resulting in excessive protection of the battery voltage and limiting battery performance. Therefore, the voltage threshold is adjusted. In this process, when the battery voltage is greater than the voltage threshold, the voltage threshold is not lowered directly at the beginning. Instead, during the voltage overvoltage protection process, a judgment is made based on the overvoltage protection duration and the preset duration to determine whether to adjust the voltage threshold. This can avoid setting the voltage threshold too low, resulting in a high error failure rate. Targeted adjustments to the voltage threshold are made based on the data during the voltage overvoltage adjustment process, so that a suitable voltage threshold can be determined, thereby improving battery performance while reducing the error failure rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] The drawings herein are incorporated into the specification and constitute a part of the specification. These drawings illustrate embodiments consistent with the present application and are used together with the specification to illustrate the technical solution of the present application. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0059] The flowcharts shown in the accompanying drawings are only exemplary and do not necessarily include all the contents and operations / steps, nor must they be executed in the order described. For example, some operations / steps can be decomposed, and some operations / steps can be combined or partially combined, so the actual execution order may change according to actual conditions.

[0060] Figure 1 An optional process diagram of an overvoltage protection method provided in an embodiment of the present application Figure 1 ;

[0061] Figure 2 A schematic diagram of an optional number of days for a vehicle to trigger a fault for the first time in an overvoltage protection method provided in an embodiment of the present application;

[0062] Figure 3 An optional process diagram of an overvoltage protection method provided in an embodiment of the present application;

[0063] Figure 4 An optional process diagram of an overvoltage protection method provided in an embodiment of the present application Figure 2 ;

[0064] Figure 5 An optional process diagram of an overvoltage protection method provided in an embodiment of the present application Figure 3 ;

[0065] Figure 6 A schematic diagram of the structure of a battery management system provided in an embodiment of the present application;

[0066] Figure 7 A schematic diagram of the structure of a vehicle provided in an embodiment of the present application. DETAILED DESCRIPTION

[0067] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the specific technical solution of the present application will be further described in detail below in conjunction with the drawings in the embodiments of the present application. The following embodiments are used to illustrate the present application, but are not used to limit the scope of the present application.

[0068] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used in this application are only for the purpose of describing the embodiments of this application and are not intended to limit this application.

[0069] In the following description, reference is made to “some embodiments”, “this embodiment”, “embodiments of the present application” and examples, etc., which describe a subset of all possible embodiments, but it can be understood that “some embodiments” may be the same subset or different subsets of all possible embodiments and may be combined with each other without conflict.

[0070] If similar descriptions of "first / second" appear in the application documents, the following instructions are added. In the following description, the terms "first\second\third" involved are merely used to distinguish similar objects and do not represent a specific ordering of the objects. It can be understood that "first\second\third" can be interchanged in a specific order or sequence where permitted, so that the embodiments of the present application described herein can be implemented in an order other than that illustrated or described herein.

[0071] An embodiment of the present application provides an overvoltage protection method for detecting the voltage of a battery of a vehicle and protecting the voltage of the battery.

[0072] Figure 1 An optional process diagram of an overvoltage protection method provided in an embodiment of the present application Figure 1 ,like Figure 1 As shown, the overvoltage protection method includes the following steps:

[0073] S101, when the voltage of the battery is greater than the voltage threshold, performing overvoltage protection;

[0074] S102 : In response to the overvoltage protection duration being greater than a preset duration, lowering a voltage threshold.

[0075] The overvoltage protection method provided in the embodiment of the present application can be applied to the voltage detection and voltage protection of various types of batteries, such as lithium-ion batteries, nickel-hydrogen batteries, lead-acid batteries, sodium-sulfur batteries, and fuel cells, etc. In this regard, the embodiment of the present application does not impose specific restrictions.

[0076] In some embodiments of the present application, lithium-ion batteries are the most commonly used battery type in new energy vehicles, with high energy density, long life and fast charging. Lithium-ion batteries are the most commonly used battery type in electric vehicles, hybrid vehicles and plug-in hybrid vehicles. Nickel-metal hydride batteries are also a relatively common type of new energy vehicle battery, with high consistency, long life and fast charging. Nickel-metal hydride batteries are commonly used in hybrid vehicles and plug-in hybrid vehicles. Lead-acid batteries are a more traditional type of battery, commonly used in traditional vehicles. Lead-acid batteries are still a common type of battery in some low-speed electric vehicles, micro electric vehicles and electric bicycles. Sodium-sulfur batteries have the characteristics of good low-temperature performance and strong environmental adaptability, but the energy density and number of cycles are relatively small. They are still under exploration and used as an alternative. Fuel cells are specifically used in fuel cell electric vehicles, including alkaline fuel cells, phosphoric acid fuel cells, molten carbonate fuel cells, solid oxide fuel cells, proton exchange membrane fuel cells and direct methanol fuel cells. The characteristic of fuel cells is that the chemical energy of fuel can be directly converted into electrical energy, with high efficiency and environmental protection.

[0077] In the following embodiments, a lithium-ion battery is used as an example for description.

[0078] In the embodiment of the present application, the voltage of the battery may be the voltage of any one of the multiple battery voltages of the battery of the vehicle; the voltage of the battery may be any one of the single cell voltages of the multiple battery voltages of the battery of the vehicle.

[0079] In some embodiments of the present application, the executor of the overvoltage protection method is a vehicle.

[0080] In some embodiments of the present application, if the voltage threshold of the vehicle is set relatively low at the beginning, it is easy to cause a high failure rate of market-side error reporting, for example, Figure 2 As shown, Figure 2 The horizontal axis is the number of days after the vehicle is sold when the fault is triggered for the first time. Figure 2 The vertical axis is the number of vehicles. Figure 2 The first bar chart shows that in the range of 0-20 days since the vehicle was sold, 12 vehicles had failures. Figure 2 Expressing that the probability of vehicle failure is very high if the voltage threshold is exceeded.

[0081] In an embodiment of the present application, the overvoltage protection duration is determined.

[0082] In some embodiments of the present application, when the obtained battery voltage is greater than the voltage threshold, voltage overvoltage protection processing is performed to determine the overvoltage protection duration for adjusting the voltage overvoltage. When the battery voltage is greater than the voltage threshold, overvoltage protection is performed; in response to the overvoltage protection duration being greater than the preset duration, the voltage threshold is lowered.

[0083] In some embodiments of the present application, the vehicle monitors the voltage value of the battery through a voltage sensor to obtain the voltage of the battery. When the obtained battery voltage is greater than the voltage threshold, the vehicle performs voltage overvoltage protection processing and determines the overvoltage protection duration for adjusting the voltage overvoltage.

[0084] It can be understood that when the battery voltage obtained by the vehicle is greater than the voltage threshold, the vehicle performs voltage overvoltage protection processing to determine the overvoltage protection duration of the adjusted voltage overvoltage, thereby judging whether it exceeds the preset duration, and then determining whether to adjust the preset voltage threshold. This can avoid setting the preset voltage threshold too low, resulting in a high error fault rate. By making targeted adjustments to the preset voltage threshold based on the data in the process of adjusting the voltage overvoltage, a suitable preset voltage threshold can be determined, thereby improving battery performance while reducing the error fault rate.

[0085] It should be noted that the overvoltage protection duration includes: the current withdrawal duration of the charging pile, and / or the total overlimit duration; the current withdrawal duration represents the reaction time of the charging pile in withdrawing the current; the total overlimit duration represents the total time it takes for the battery voltage to recover to the voltage threshold after it exceeds the voltage threshold. Among them, the current withdrawal duration represents the time it takes for the charging pile to start the current withdrawal operation and the current value of the charging pile to become zero. The total overlimit duration represents the total time it takes for the battery voltage to recover to the voltage threshold after it exceeds the voltage threshold.

[0086] In some embodiments of the present application, during the continuous charging process of the vehicle battery, the voltage at the charging terminal of the battery pack rises very quickly. After reaching the overvoltage protection threshold (i.e., the voltage threshold), the single cell overvoltage protection strategy is turned on. The process of executing the protection strategy is as follows: Figure 3 As shown, it includes: continuous charging stage, diagnosis stage, BMS (battery management system) control module returns the current to 0, charging pile reaction stage and charging pile disconnection relay, and the battery cell begins to degrade. Figure 3 The figure shows how the battery pack charging terminal voltage changes over time.

[0087] For example, Figure 3 As shown, at time A, the maximum single cell voltage of the battery reaches 3.8V (i.e. Figure 3 The voltage at midpoint 1 is 3.8V), and the fault setting threshold is 3.8V. From time A for 2s to time B (i.e., the diagnosis phase), the BMS full charge mark position is at this time. At this time, the single cell voltage at time B is 3.808V (i.e., Figure 3 The voltage at midpoint 2 is 3.808V). From time B, the BMS charging control module starts the backward charging process. At time C, the BMS requests the current to drop to 0 and sends chargecomplete (charging completed) to CAN (the controller in the vehicle). At this time, the single cell voltage at time C is 3.818V (i.e. Figure 3 The voltage at midpoint 3 is 3.818V). From time C to time D, the charging pile reduces the output current to 0, and the cell voltage changes from 3.818 to 3.822V. The cell voltage at time D is 3.822V (i.e. Figure 3 The voltage at midpoint 4 is 3.822V). At time D, the DC relay is disconnected, the cell begins to depolarize, and at time E, the cell voltage is 3.8V (i.e. Figure 3 The voltage at midpoint 5 is 3.8V).

[0088] For example, the current reduction time may be Figure 3 The time from time C to time D in .

[0089] When the battery voltage obtained by the vehicle is greater than the voltage threshold, the vehicle performs voltage overvoltage protection processing to determine the overvoltage protection duration for adjusting the voltage overvoltage. If the overvoltage protection duration is greater than the preset duration, it means that the voltage threshold at this time is set unreasonably, that is, the voltage threshold is too high, resulting in excessive protection of the battery voltage and limiting battery performance. Therefore, the voltage threshold is adjusted. In this process, the voltage threshold is not directly lowered at the beginning when the battery voltage is greater than the voltage threshold. Instead, during the voltage overvoltage protection process, a judgment is made based on the overvoltage protection duration and the preset duration to determine whether to adjust the voltage threshold. This can avoid setting the voltage threshold too low and resulting in a high error fault rate. Targeted voltage threshold adjustments are made based on the data in the process of adjusting the voltage overvoltage, and the appropriate voltage threshold can be determined, thereby improving battery performance while reducing the error fault rate.

[0090] In some embodiments of the present application, Figure 4 As shown, S101 and S102 may include:

[0091] S1021: If the overvoltage protection duration is greater than the preset duration, a voltage deviation value is determined during the voltage overvoltage process.

[0092] In some embodiments of the present application, the preset duration includes: a limit duration and an over-limit duration.

[0093] In some embodiments of the present application, if the overvoltage protection duration is greater than a preset duration, the vehicle determines a voltage deviation value based on the excess duration during the process of adjusting the voltage overvoltage.

[0094] In some embodiments of the present application, since the overvoltage protection duration includes: at least one of: the retreat current duration, the total overlimit duration, the retreat current duration and the total overlimit duration, the vehicle can determine the voltage deviation value based on the overlimit duration when the retreat current duration in the overvoltage protection duration is greater than the limit duration; or, when the total overlimit duration in the overvoltage protection duration is greater than the overlimit limit duration, determine the voltage deviation value based on the overlimit duration; or, when the retreat current duration is greater than the limit duration and the total overlimit duration is greater than the overlimit limit duration, determine the voltage deviation value based on the overlimit duration.

[0095] S1022. Lower the voltage threshold based on the voltage deviation value.

[0096] In some embodiments of the present application, the preset voltage threshold is adjusted based on the voltage deviation value to determine the target voltage threshold.

[0097] It should be noted that, in response to the overvoltage protection duration being greater than the preset duration, the target voltage threshold obtained by lowering the voltage threshold is the difference between the voltage threshold and the voltage deviation value.

[0098] In some embodiments of the present application, the target voltage threshold is an adjusted voltage threshold, which can be used when performing overvoltage detection on the battery voltage next time.

[0099] In some embodiments of the present application, the vehicle may perform a difference operation on the voltage threshold and the voltage deviation value to determine the target voltage threshold.

[0100] Exemplarily, the voltage threshold is 3.8V, the voltage deviation value is 0.02V, and the target voltage threshold is 3.8-0.02=3.78V.

[0101] It can be understood that when the overvoltage protection duration is greater than the preset duration, determining the voltage deviation value during the process of adjusting the voltage overvoltage can accurately determine the accuracy of the voltage to be adjusted, so that the voltage threshold can be adjusted subsequently through the voltage deviation value.

[0102] In some embodiments of the present application, determining the overvoltage protection duration may be achieved through S1011, or S1012, or S1013, as follows:

[0103] S1011. When the voltage is greater than the voltage threshold, overvoltage protection is performed and a current withdrawal time is determined.

[0104] In some embodiments of the present application, when the battery voltage is greater than the voltage threshold, the vehicle can perform voltage overvoltage protection processing, obtain the time of the charging pile reaction phase, and determine the current reduction duration of the charging pile.

[0105] For example, Figure 3The time from moment C to moment D in (i.e. the time corresponding to the charging pile reaction stage).

[0106] In some embodiments of the present application, when the battery voltage is greater than a voltage threshold, a flag is set through the battery voltage; when the flag is at a first value, voltage overvoltage protection is performed to determine the voltage value within a preset time period; when the voltage value is greater than the voltage threshold, the current reduction strategy and the current reduction operation of the charging pile are executed to determine the current reduction duration.

[0107] It should be noted that the flag is used to enable the overvoltage protection strategy. The preset time period can be 2 seconds, for example, Figure 3 The time from time A to time B. The voltage value within the preset time period can be Figure 3 The first value may be 1 or True, and this embodiment of the present application does not impose any specific limitation on this.

[0108] In some embodiments of the present application, the vehicle monitors the voltage value of the battery of the vehicle through a voltage sensor to obtain the voltage of the battery. When the voltage of the battery is greater than the voltage threshold, the flag is set through the voltage of the battery, and the flag is set from the second value to the first value. When the flag is at the first value, voltage overvoltage protection processing is performed, and the average voltage value within a preset time period is determined. When the average voltage value is greater than the voltage threshold, the current reduction strategy and the current reduction operation of the charging pile are executed, and the current reduction duration is calculated.

[0109] Exemplary, the back-off current strategy can be Figure 3 The BMS control module in the charging pile can reduce the current to 0. Figure 3 Middle charging pile reaction stage.

[0110] It can be understood that the vehicle obtains the voltage of the vehicle's battery; when the battery voltage is greater than the voltage threshold, the flag is set through the battery voltage; when the flag is at the first value, voltage overvoltage protection processing is performed to determine the voltage value within a preset time period; when the voltage value is greater than the voltage threshold, the secondary voltage is compared with the voltage threshold to decide whether to execute the current reduction strategy and the current reduction operation of the charging pile, which can avoid the battery voltage being too high due to misoperation and reduce unnecessary execution of the current reduction strategy and the current reduction operation of the charging pile.

[0111] S1012: When the voltage is greater than the voltage threshold, perform overvoltage protection and determine the overlimit duration; and determine the total overlimit duration based on the overlimit duration.

[0112] In some embodiments of the present application, the overtime duration represents the time it takes for the voltage of the battery to recover to the voltage threshold after it exceeds the voltage threshold for the last time.

[0113] For example, the overtime period is Figure 3 The time from time A to time E.

[0114] In some embodiments of the present application, the vehicle monitors the voltage value of the battery of the vehicle through a voltage sensor to obtain the voltage of the battery. When the obtained battery voltage is greater than the voltage threshold, voltage overvoltage protection processing is performed and the overlimit duration is calculated. After the overlimit duration in the current charging process is obtained, the total overlimit duration of the battery of the vehicle is calculated.

[0115] In some embodiments of the present application, determining the total overlimit duration based on the overlimit duration includes: obtaining the historical overlimit times of the battery voltage; determining the historical overlimit durations corresponding to each of the historical overlimit times based on the historical overlimit times of the battery voltage; and determining the total overlimit duration based on the overlimit duration and the historical overlimit duration.

[0116] In some embodiments of the present application, the vehicle obtains the historical number of times the battery voltage exceeds the limit; based on the historical number of times the battery voltage exceeds the limit, the historical overtime duration corresponding to each historical overtime number is determined; and the overtime duration and the historical overtime duration are summed to obtain the total overtime duration.

[0117] Exemplarily, the number of times the voltage of the battery exceeds the limit in history is N. t2 is the duration of the limit exceeding, and ttotal is equal to the cumulative sum of t2 of N+1 times.

[0118] It can be understood that the vehicle obtains the historical number of times the battery voltage exceeds the limit; based on the historical number of times the battery voltage exceeds the limit, the historical over-limit duration corresponding to each historical over-limit number is determined, and the total over-limit duration is determined by performing calculations through the over-limit duration and the historical over-limit duration, so as to facilitate the subsequent comparison of the total over-limit duration with the preset duration to determine the life of the battery cells and whether to adjust the voltage threshold according to the life of the battery cells.

[0119] S1013. When the voltage of the battery is greater than the voltage threshold, perform overvoltage protection, determine the current withdrawal time and the over-limit time; and determine the total over-limit time based on the over-limit time.

[0120] In some embodiments of the present application, the vehicle monitors the voltage value of the battery of the vehicle through a voltage sensor to obtain the voltage of the battery. When the obtained battery voltage is greater than the voltage threshold, voltage overvoltage protection processing is performed to calculate the current withdrawal time and the overlimit time. The overlimit time is calculated to determine the total overlimit time.

[0121] It should be noted that the specific implementation process of determining the total excess time by calculating the excess time is consistent with the specific implementation process of determining the total excess time by calculating the excess time in S1012, and will not be repeated here.

[0122] It can be understood that when the obtained battery voltage is greater than the voltage threshold, the vehicle performs voltage overvoltage protection processing to determine the current withdrawal time, or, when the obtained battery voltage is greater than the voltage threshold, the vehicle performs voltage overvoltage protection processing to determine the over-limit time; and performs calculations based on the over-limit time to determine the total over-limit time, or, when the obtained battery voltage is greater than the voltage threshold, the vehicle performs voltage overvoltage protection processing to determine the current withdrawal time and the over-limit time; and determines the total over-limit time based on the over-limit time. The overvoltage protection time is determined in three ways, which enriches the overvoltage protection time determination method and thus enriches the diversity of voltage threshold adjustment.

[0123] In some embodiments of the present application, the overvoltage protection method also includes: obtaining the historical over-limit duration of the battery voltage; the historical over-limit duration is the over-limit duration corresponding to each of the number of times the battery voltage has historically exceeded the voltage threshold; determining the total over-limit duration; the total over-limit duration is the sum of the over-limit duration and the historical over-limit duration.

[0124] It can be understood that the vehicle obtains the historical over-limit duration of the battery voltage and determines the total over-limit duration through the historical over-limit duration, so as to facilitate the subsequent comparison of the total over-limit duration with the preset duration to determine the life of the battery cells and whether to adjust the voltage threshold according to the battery life.

[0125] In some embodiments of the present application, the overvoltage protection method further includes:

[0126] When the battery voltage is greater than the voltage threshold, the number of times the battery voltage exceeds the limit is counted to determine the latest number of times; the latest number of times of exceeding the limit is used to determine the historical number of times of exceeding the limit during the next voltage overvoltage detection process on the battery voltage.

[0127] In some embodiments of the present application, the vehicle monitors the voltage value of the battery of the vehicle through a voltage sensor to obtain the voltage of the battery. When the obtained battery voltage is greater than the voltage threshold, the number of times the battery voltage exceeds the limit is updated to determine the latest number of times the battery voltage exceeds the limit.

[0128] For example, the latest number of limit violations is N+1

[0129] It is understandable that the vehicle counts and updates the number of times the battery voltage exceeds the limit, which is helpful for determining the next historical number of exceeding the limit, so as to determine the next total duration of exceeding the limit through the next historical number of exceeding the limit.

[0130] In some embodiments of the present application, S1021 may be implemented by S201 as follows:

[0131] S201: If the overvoltage protection duration is greater than a preset duration, a voltage deviation value is determined based on a voltage value corresponding to the excessive duration during the overvoltage protection process.

[0132] It is understandable that when the overvoltage protection duration is greater than the preset duration, in the process of adjusting the voltage overvoltage, the voltage deviation value is determined based on the excess duration, so that the accuracy of the voltage to be adjusted can be accurately determined.

[0133] In some embodiments of the present application, the preset duration includes: a limit duration; the limit duration represents the normal duration from when the charging pile starts to perform the current reduction operation to when the current value of the charging pile becomes zero;

[0134] When the current reduction time in the overvoltage protection time is greater than the limit time, the voltage deviation value is determined based on the voltage value corresponding to the excess time.

[0135] In some embodiments of the present application, the preset duration includes: an over-limit duration; the over-limit duration represents the duration of the battery voltage response battery life;

[0136] When the total over-limit duration in the overvoltage protection duration is greater than the over-limit limit duration, the voltage deviation value is determined based on the voltage value corresponding to the over-limit duration.

[0137] In some embodiments of the present application, the preset duration includes: a limit duration and an over-limit limit duration;

[0138] When the current withdrawal time is greater than the limit time, and the total exceeding time is greater than the exceeding limit time, the voltage deviation value is determined based on the voltage value corresponding to the exceeding time.

[0139] In some embodiments of the present application, when the current withdrawal time in the overvoltage protection time is greater than the limit time, the voltage deviation value is determined based on the voltage value corresponding to the excess time; or, when the total excess time in the overvoltage protection time is greater than the excess limit time, the voltage deviation value is determined based on the voltage value corresponding to the excess time; or, when the current withdrawal time is greater than the limit time and the total excess time is greater than the excess limit time, the voltage deviation value is determined based on the voltage value corresponding to the excess time.

[0140] In some embodiments of the present application, when the current withdrawal time in the overvoltage protection time is greater than the limit time, in the process of adjusting the voltage overvoltage, based on the excess time, it is determined that the battery voltage exceeds the voltage threshold and then recovers to the voltage average value within the time period corresponding to the voltage threshold.

[0141] In some embodiments of the present application, when the total over-limit duration in the overvoltage protection duration is greater than the over-limit limit duration, in the process of adjusting the voltage overvoltage, based on the over-limit duration, it is determined that the battery voltage exceeds the voltage threshold and then recovers to the voltage average value within the time period corresponding to the voltage threshold.

[0142] In some embodiments of the present application, when the current withdrawal time is greater than the limit time, and the total exceeding time is greater than the exceeding limit time, in the process of adjusting the voltage overvoltage, based on the exceeding time, it is determined that the battery voltage exceeds the voltage threshold and then recovers to the voltage average value within the time period corresponding to the voltage threshold.

[0143] It should be noted that the time period from when the battery voltage exceeds the voltage threshold and then returns to the voltage threshold is the over-limit duration (i.e., Figure 3 The voltage deviation value is the average voltage increase value.

[0144] It can be understood that when the vehicle's current withdrawal time in the overvoltage protection time is greater than the limit time, the voltage deviation value is determined based on the excess time; or, when the total excess time in the overvoltage protection time is greater than the excess limit time, the voltage deviation value is determined based on the excess time; or, when the current withdrawal time is greater than the limit time and the total excess time is greater than the excess limit time, the voltage deviation value is determined based on the excess time. Calculating the voltage deviation value according to the excess time based on at least one of the three situations can facilitate subsequent adjustment of the voltage threshold to obtain the target voltage threshold, making the target voltage threshold more accurate, thereby reducing the error reporting failure rate.

[0145] In some embodiments of the present application, the voltage value corresponding to the exceeded time duration is a first voltage value corresponding to each time duration node within the exceeded time duration; and the voltage deviation value is determined based on the voltage value corresponding to the exceeded time duration, including:

[0146] Determine the second voltage value corresponding to each duration node within the exceeded duration; the second voltage value is the difference between the first voltage value and the voltage threshold; determine the total voltage value of the exceeded duration; the total voltage value is the sum of the second voltage values ​​corresponding to each duration node; determine the voltage deviation value; the voltage deviation value is the ratio of the total voltage value to the exceeded duration.

[0147] In some embodiments of the present application, based on the excess time length, a first voltage value corresponding to each time node within the excess time length is determined; based on the voltage threshold and the first voltage value, a second voltage value corresponding to each time node is determined; the second voltage values ​​are summed to determine the total voltage value of the excess time length; based on the total voltage value and the excess time length, a quotient operation is performed to determine the voltage deviation value.

[0148] In some embodiments of the present application, the vehicle can determine the first voltage value corresponding to each time node within the overrun duration based on the overrun duration, and obtain the second voltage value (i.e., voltage increase value) corresponding to each time node by performing a difference operation between the first voltage value corresponding to each time node and the voltage threshold. Perform a sum operation on the second voltage value corresponding to each time node to determine the total voltage value of the overrun duration; perform a quotient operation based on the total voltage value and the overrun duration to determine the voltage deviation value.

[0149] It can be understood that the vehicle determines the first voltage value corresponding to each time node within the excess time based on the excess time; determines the second voltage value corresponding to each time node based on the voltage threshold and the voltage value; performs a sum operation on the second voltage values ​​to determine the total voltage value of the excess time; and performs a quotient operation based on the total voltage value and the excess time to determine the voltage deviation value. The entire process of determining the voltage deviation value is determined based on the data in the voltage overvoltage protection processing process, so that the determined voltage deviation value is more targeted, and then the voltage threshold is adjusted based on the voltage deviation value to obtain the target voltage threshold, so that the target voltage threshold is more accurate, thereby reducing the error fault rate.

[0150] In some embodiments of the present application, when the voltage of the battery is greater than the voltage threshold, voltage overvoltage protection processing is performed to determine the current withdrawal time and the overlimit time; and after determining the total overlimit time based on the overlimit time, the method further includes:

[0151] If the total over-limit duration is less than or equal to the over-limit limit duration, then when the current withdrawal duration is greater than the limit duration, the voltage deviation value is determined based on the voltage value corresponding to the over-limit duration.

[0152] In some embodiments of the present application, if the total exceeding time is less than or equal to the exceeding limit time, then when the current withdrawal time is greater than the limit time, the voltage deviation value is determined based on the exceeding time.

[0153] It should be noted that determining the voltage deviation value based on the voltage value corresponding to the exceeding time length is the same as determining the voltage deviation value based on the exceeding time length in S201, and will not be repeated here.

[0154] It can be understood that if the total exceeding time is less than or equal to the exceeding limit time, then when the retreat current time is greater than the limit time, the voltage deviation value is determined based on the exceeding time. The entire process of determining the voltage deviation value is determined based on the data in the overvoltage protection processing process, so that the determined voltage deviation value is more targeted, and then the voltage threshold is adjusted based on the voltage deviation value to obtain the target voltage threshold, so that the target voltage threshold is more accurate, thereby reducing the error failure rate.

[0155] In some embodiments of the present application, after executing S102, the following steps are further performed:

[0156] S103, resetting the flag bit through the target voltage threshold.

[0157] In some embodiments of the present application, after the target voltage threshold is obtained, the flag bit is reset using the target voltage threshold.

[0158] S104: When the flag bit is at the second value, determine an updated voltage threshold.

[0159] In some embodiments of the present application, when the flag bit is at the second value, the target voltage threshold is determined as the updated voltage threshold.

[0160] It should be noted that the second value can be 0 or False, and this embodiment of the present application does not impose any specific limitation on this.

[0161] S105. Perform overvoltage protection on the battery of the vehicle using the updated voltage threshold.

[0162] In some embodiments of the present application, the battery of the vehicle is protected from overvoltage by using an updated voltage threshold.

[0163] It can be understood that the vehicle resets the flag through the target voltage threshold; when the flag is at the second value, the updated voltage threshold is determined; through the updated voltage threshold, the vehicle's battery is protected from overvoltage. Performing overvoltage protection according to the appropriate voltage threshold can improve battery performance while reducing the error failure rate.

[0164] In some embodiments of the present application, the following is an explanation using a single battery as an example. Figure 3 From the analysis, it can be seen that the core points that affect the voltage overvoltage problem are the voltage threshold and the detection interval time, and the interval time A→C is the necessary time for fault diagnosis (considering the robustness of the strategy, the setting time and action time are required), so the first-level strategy only needs to focus on the analysis of C→E. The second-level strategy analyzes the A→E point as a whole. The overvoltage protection method includes strategy 1 (i.e., the first-level strategy) and / or strategy 2 (i.e., the second-level strategy). The executor is the vehicle controller, and the hardware related to the controller is the voltage sensor, which is used to monitor the voltage value of the battery.

[0165] Strategy 1: By calculating the time of the charging pile's current reduction, the charging piles are graded. When the time of the charging pile's current reduction is longer than the charging pile's current reduction limit reaction time, the voltage upper limit threshold is adjusted to protect the battery cell performance.

[0166] Strategy 2: By calculating the total time exceeding the upper voltage threshold (i.e. Figure 3 The AE time difference, t2), is used to evaluate the overall impact on life. After meeting the requirements (i.e., calculating ttotal through t2, ttotal is greater than t0'), the upper limit threshold is adjusted to protect the performance of the battery cell. The two-level strategy is used together, that is, the charging piles are graded to ensure that the piles with high reaction rates can be fully charged; the total time exceeding the threshold can also be monitored, and compared with the life threshold, the time of limiting power can be reduced. The two-level strategy effectively improves the battery power.

[0167] It should be noted that t is the total duration of exceeding the limit; t0' is the total time / s that the cell voltage exceeds the upper limit, that is, the duration of exceeding the limit.

[0168] In some embodiments of the present application, the voltage value of the battery is continuously monitored by a voltage sensor, denoted as U1. When U1>voltage threshold U0, the battery voltage protection strategy flag is set (software flag), and the average voltage within 2s is calculated, denoted as U2 (i.e., the voltage value within a preset time period). When U2>U0, the BMS control module executes the current reduction strategy, and at the same time, when the number of times the limit is exceeded is N+1, the charging pile is controlled to perform the current reduction action, and then the strategy hierarchical control is started.

[0169] Strategy 1, calculate the time for the charging pile to withdraw the current, that is, the time from C to D, recorded as t1. When t1> the charging pile (i.e., the low-speed charging pile) withdrawal current limit reaction time t0, calculate the average increase value exceeding the voltage threshold (i.e. Figure 3 The average growth value of AE exceeding the preset threshold voltage) adjusts the single cell upper voltage threshold U0→U0' (U0' is the target voltage threshold), then resets the flag and re-detects the battery voltage value in real time.

[0170] Strategy 2, calculate the time difference t2 after exceeding U0 and returning to U0 (save t2 after each calculation), calculate the total time / s that the monomer exceeds the voltage threshold, obtain t2 each time in N times, ttotal is equal to the cumulative sum of t2 of N+1 times, if ttotal>t0', calculate the average growth value exceeding the voltage threshold, adjust the upper voltage threshold U0→U0', then reset the flag bit, and re-detect the monomer voltage value in real time.

[0171] Through two-level matching of Strategy 1 and Strategy 2, the battery power is guaranteed and the failure rate on the market side is reduced.

[0172] It should be noted that Strategy 1 and Strategy 2 need to be tested in the laboratory in advance as follows to predict the lifespan, which is used for strategy data input to ensure the rationality of the target voltage threshold. The battery cell overvoltage test scheme is shown in Table 1, including: serial number, test upper limit voltage, test quantity and test duration. The serial numbers include: 1, 2 and 3. The test upper limit voltage includes: upper limit voltage in the battery cell parameter table, upper limit voltage in the battery cell parameter table + 0.2V and upper limit voltage in the battery cell parameter table + 0.4V. The upper limit voltage is the voltage threshold. The number of tests is 3, and the test duration is 200 / 400 / 600cycle disassembly 1EA, that is, the test duration of serial number 1 is 200, the test duration of serial number 2 is 400, and the test duration of serial number 3 is 600.

[0173] Table 1

[0174]

[0175] In some embodiments of the present application, Figure 5 An optional process diagram of an overvoltage protection method provided in an embodiment of the present application Figure 4 , the overvoltage protection method is shown in the following steps:

[0176] S1, continuously monitor the single cell voltage value U1.

[0177] In some embodiments of the present application, U1 is the actual measured value of the battery voltage, that is, the battery voltage.

[0178] S2. Determine whether U1>U0?

[0179] In some embodiments of the present application, U0 is a cell upper voltage threshold (ie, voltage threshold). If yes, then execute S3; if no, then execute S1.

[0180] S3. Set the protection strategy flag of the single cell voltage.

[0181] S4. Calculate the mean value U2 of the voltage within 2s.

[0182] In some embodiments of the present application, the average value of the voltage within 2s, i.e. Figure 3 The average voltage from time A to time B.

[0183] S5. Judgment U2>U0?

[0184] In some embodiments of the present application, if yes, execute S6; if no, execute S16.

[0185] S6. The BMS control module executes the current reduction strategy.

[0186] In some embodiments of the present application, S7 and S8 are executed after S6 is executed. There is no specific execution order for S7 and S8, and the specific execution order depends on the specific situation.

[0187] S7. The charging pile performs a current reduction operation.

[0188] In some embodiments of the present application, S9 and / or S11 are executed after executing S7.

[0189] S8. Record the number of times the cell voltage exceeds the limit (N+1).

[0190] S9, calculating the time t1 for the charging pile to withdraw current.

[0191] In some embodiments of the present application, the time t1 of the current withdrawal, i.e. Figure 3 Medium CD time.

[0192] S10. Judgment t1>t0?

[0193] In some embodiments of the present application, t0 is the charging pile current limit reaction time. If yes, then execute S14; if no, then execute S16.

[0194] S11, calculating the time difference t2 after exceeding U0 and returning to U0.

[0195] In some embodiments of the present application, t2 is the time after exceeding U0 and returning to U0, that is, Figure 3 The time from A to E (i.e. the duration of the excess).

[0196] S12, calculating the total time ttotal that the cell voltage exceeds the voltage threshold.

[0197] In some embodiments of the present application, ttotal is the total time that the cell voltage exceeds the voltage threshold, and ttotal is equal to the cumulative sum of N+1 times t2.

[0198] S13, judge t total > t0'?

[0199] In some embodiments of the present application, t0' is the total time of the cell voltage exceeding the upper limit (ie, the duration of exceeding the limit). If yes, execute S14; if no, execute S10.

[0200] S14, calculating the average increase value of the cell voltage exceeding the voltage threshold.

[0201] S15 . Adjust the upper voltage threshold U0 - U0 ′ of the battery cell.

[0202] In some embodiments of the present application, U0' is an adjusted upper voltage threshold (ie, target voltage threshold) of a single cell of the battery.

[0203] S16, reset the flag bit.

[0204] It can be understood that in the process of voltage overvoltage protection, whether to adjust the voltage threshold is determined based on the overvoltage protection duration and the preset duration, so as to avoid setting the voltage threshold too low and resulting in a high error failure rate. Targeted adjustment of the voltage threshold is performed based on the data in the process of adjusting the voltage overvoltage, and the appropriate voltage threshold can be determined, thereby improving battery performance while reducing the error failure rate.

[0205] The present application provides a battery management system. Figure 6 A schematic diagram of a battery management system provided in an embodiment of the present application is shown in FIG. Figure 6 As shown, the battery management system 7 includes: a controller 701; wherein,

[0206] The controller 701 is used to perform overvoltage protection when the voltage of the battery is greater than a voltage threshold; in response to the overvoltage protection duration being greater than a preset duration, the voltage threshold is lowered.

[0207] In some embodiments of the present application, the controller 701 is further configured to determine the overvoltage protection duration before lowering the voltage threshold in response to the overvoltage protection duration being greater than a preset duration.

[0208] In some embodiments of the present application, the overvoltage protection duration includes: the current withdrawal duration of the charging pile; the current withdrawal duration represents the time taken from the charging pile starting to perform the current withdrawal operation to the current value of the charging pile becoming zero;

[0209] The controller 701 is also used to perform overvoltage protection and determine the current withdrawal time when the voltage is greater than the voltage threshold.

[0210] In some embodiments of the present application, the overvoltage protection duration includes: the total overlimit duration; the total overlimit duration represents the total duration of time after the voltage of the battery exceeds the voltage threshold and then recovers to the voltage threshold;

[0211] The controller 701 is also used to perform overvoltage protection when the voltage is greater than the voltage threshold and determine the overlimit time; the overlimit time represents the time it takes for the battery voltage to recover to the voltage threshold after exceeding the voltage threshold for the last time; based on the overlimit time, the total overlimit time is determined.

[0212] In some embodiments of the present application, the overvoltage protection duration includes: the current withdrawal duration and the total overlimit duration of the charging pile;

[0213] The controller 701 is also used to perform overvoltage protection when the battery voltage is greater than the voltage threshold, determine the current withdrawal time and the over-limit time; and determine the total over-limit time based on the over-limit time.

[0214] In some embodiments of the present application, the controller 701 is also used to obtain the historical over-limit duration of the battery voltage; the historical over-limit duration is the over-limit duration corresponding to the number of times the battery voltage exceeds the voltage threshold in history; determine the total over-limit duration; the total over-limit duration is the sum of the over-limit duration and the historical over-limit duration.

[0215] In some embodiments of the present application, the controller 701 is further used to determine a voltage deviation value during the overvoltage protection process if the overvoltage protection duration is greater than a preset duration; and to lower the voltage threshold based on the voltage deviation value.

[0216] In some embodiments of the present application, the controller 701 is further used to determine the voltage deviation value based on the voltage value corresponding to the excess time duration during the overvoltage protection process if the overvoltage protection time duration is greater than a preset time duration.

[0217] In some embodiments of the present application, the preset duration includes: a limit duration; the limit duration represents the normal duration from when the charging pile starts to perform the current reduction operation to when the current value of the charging pile becomes zero;

[0218] The controller 701 is further used to determine the voltage deviation value based on the voltage value corresponding to the excessive time length when the current withdrawal time length in the overvoltage protection time length is greater than the limit time length.

[0219] In some embodiments of the present application, the preset duration includes: an over-limit duration; the over-limit duration represents the duration of the battery voltage response battery life;

[0220] The controller 701 is further configured to determine a voltage deviation value based on a voltage value corresponding to the over-limit duration when the total over-limit duration in the over-voltage protection duration is greater than the over-limit limit duration.

[0221] In some embodiments of the present application, the preset duration includes: a limit duration and an over-limit limit duration;

[0222] The controller 701 is further used to determine the voltage deviation value based on the voltage value corresponding to the exceeding time length when the current withdrawal time length is greater than the limit time length and the exceeding total time length is greater than the exceeding limit time length.

[0223] In some embodiments of the present application, the controller 701 is also used to perform overvoltage protection when the battery voltage is greater than the voltage threshold, and to determine the current withdrawal time and the over-limit time; after determining the total over-limit time based on the over-limit time, if the total over-limit time is less than or equal to the over-limit limit time, then when the current withdrawal time is greater than the limit time, the voltage deviation value is determined based on the voltage value corresponding to the over-limit time.

[0224] In some embodiments of the present application, the voltage value corresponding to the exceeded time duration is the first voltage value corresponding to each time duration node within the exceeded time duration;

[0225] Controller 701 is also used to determine the second voltage value corresponding to each time node within the exceeded time; the second voltage value is the difference between the first voltage value and the voltage threshold; determine the total voltage value of the exceeded time; the total voltage value is the sum of the second voltage values ​​corresponding to each time node; determine the voltage deviation value; the voltage deviation value is the ratio of the total voltage value to the exceeded time.

[0226] In some embodiments of the present application, in response to the overvoltage protection duration being greater than a preset duration, the target voltage threshold obtained by lowering the voltage threshold is the difference between the voltage threshold and the voltage deviation value.

[0227] Based on the overvoltage protection method of the above embodiment, the embodiment of the present application also provides a vehicle, such as Figure 7 As shown, Figure 7 The schematic diagram of the structure of a vehicle provided in an embodiment of the present application is as follows. The vehicle 8 includes: a battery management system 7 and a battery 801. The battery management system 7 is used to call and run a computer program from a memory to execute the overvoltage protection method in the above embodiment.

[0228] In the embodiment of the present application, the controller of the battery management system 7 can be at least one of an Application Specific Integrated Circuit (ASIC), a Digital Signal Processor (DSP), a Digital Signal Processing Device (DSPD), a Programmable Logic Device (PLD), a Field Programmable Gate Array (FPGA), a Central Processing Unit (CPU), a controller, a microcontroller, and a microprocessor. It can be understood that for different devices, the electronic device used to implement the above-mentioned processor function can also be other, and the embodiment of the present application does not specifically limit it.

[0229] If the integrated unit is implemented in the form of a software function module and is not sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this embodiment is essentially or the part that contributes to the prior art or all or part of the technical solution can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes a number of instructions for enabling the vehicle to execute all or part of the steps of the method of this embodiment.

[0230] The modules described above as separate components may or may not be physically separated, and the components displayed as modules may or may not be physical modules; they may be located in one place or distributed on multiple network units; some or all of the modules may be selected according to actual needs to achieve the purpose of the present embodiment.

[0231] In addition, all functional modules in the embodiments of the present application can be integrated into one processing unit, or each module can be a separate unit, or two or more modules can be integrated into one unit; the above-mentioned integrated modules can be implemented in the form of hardware or in the form of hardware plus software functional units. It should be understood that "one embodiment" or "an embodiment" mentioned in this application means that specific features, structures or characteristics related to the embodiment are included in at least one embodiment of the present disclosure. Therefore, "in one embodiment" or "in one embodiment" appearing throughout the specification does not necessarily refer to the same embodiment. In addition, these specific features, structures or characteristics can be combined in one or more embodiments in any suitable manner.

[0232] It should be understood that in various embodiments of the present application, the size of the serial number of each step / process does not mean the order of execution, and the execution order of each step / process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiment of the present disclosure. The serial numbers of the above embodiments of the present disclosure are only for description and do not represent the advantages and disadvantages of the embodiments.

[0233] It should be noted that, in the application, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "includes a ..." does not exclude the existence of other identical elements in the process, method, article or device including the element.

[0234] In the several embodiments provided in the present application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. The device embodiments described above are only schematic. For example, the division of units is only a logical function division. There may be other division methods in actual implementation, such as: multiple units or components can be combined, or can be integrated into another system, or some features can be ignored or not executed. In addition, the coupling, direct coupling, or communication connection between the components shown or discussed can be through some interfaces, and the indirect coupling or communication connection of devices or units can be electrical, mechanical or other forms.

[0235] The methods disclosed in several method embodiments provided in the embodiments of the present application can be arbitrarily combined without conflict to obtain new method embodiments.

[0236] The features disclosed in several product embodiments provided in the embodiments of the present application can be arbitrarily combined without conflict to obtain new product embodiments.

[0237] The features disclosed in several method or device embodiments provided in the embodiments of the present application can be arbitrarily combined without conflict to obtain new method embodiments or device embodiments.

[0238] The above are only implementation methods of the embodiments of the present application, but the protection scope of the embodiments of the present application is not limited to this. Any technician familiar with the technical field can easily think of changes or replacements within the technical scope disclosed in this application, which should be covered by the protection scope of the embodiments of the present application.

Claims

1. An overvoltage protection method, characterized in that: include: When the battery voltage is greater than the voltage threshold, overvoltage protection is performed; In response to the overvoltage protection duration being greater than a preset duration, lowering the voltage threshold; Among them, the overvoltage protection duration includes: the current withdrawal duration of the charging pile, and / or the total over-limit duration; the current withdrawal duration represents the time taken for the charging pile to start the current withdrawal operation and for the current value of the charging pile to become zero; the total over-limit duration represents the total time it takes for the battery voltage to return to the voltage threshold after exceeding the voltage threshold each time.

2. The method according to claim 1, characterized in that In response to the overvoltage protection duration being greater than the preset duration, before lowering the voltage threshold, the overvoltage protection method further includes: Determine the overvoltage protection duration.

3. The overvoltage protection method according to claim 2, characterized in that: The determining the overvoltage protection duration includes: When the voltage is greater than the voltage threshold, overvoltage protection is performed and the current withdrawal time is determined.

4. The overvoltage protection method according to claim 2, characterized in that: The determining the overvoltage protection duration includes: When the voltage is greater than the voltage threshold, overvoltage protection is performed and the overlimit duration is determined; the overlimit duration represents the duration for the battery voltage to return to the voltage threshold after the voltage exceeds the voltage threshold for the last time; Based on the exceeding time duration, the total exceeding time duration is determined.

5. The overvoltage protection method according to claim 2, characterized in that: The determining the overvoltage protection duration includes: When the voltage of the battery is greater than the voltage threshold, overvoltage protection is performed to determine the current withdrawal time and the overlimit time; Based on the exceeding time duration, the total exceeding time duration is determined.

6. The overvoltage protection method according to claim 4 or 5, characterized in that: The determining the total overtime duration based on the overtime duration includes: Obtaining a historical over-limit duration of the voltage of the battery; the historical over-limit duration is the over-limit duration corresponding to each of the over-limit times that the voltage of the battery exceeds the voltage threshold in history; Determine the total overtime duration; the total overtime duration is the sum of the overtime duration and the historical overtime duration.

7. The overvoltage protection method according to any one of claims 1 to 5, characterized in that: In response to the overvoltage protection duration being greater than a preset duration, lowering the voltage threshold comprises: If the overvoltage protection duration is greater than the preset duration, determining a voltage deviation value during the overvoltage protection process; Based on the voltage deviation value, the voltage threshold is lowered.

8. The overvoltage protection method according to claim 7, characterized in that: If the overvoltage protection duration is greater than the preset duration, determining a voltage deviation value during the overvoltage protection process includes: If the overvoltage protection duration is greater than the preset duration, the voltage deviation value is determined based on the voltage value corresponding to the excessive duration during the overvoltage protection process.

9. The overvoltage protection method according to claim 8, characterized in that: The preset duration includes: a limit duration; the limit duration represents the normal duration from when the charging pile starts to perform the current reduction operation to when the current value of the charging pile becomes zero; If the overvoltage protection duration is greater than the preset duration, determining the voltage deviation value based on the voltage value corresponding to the excessive duration during the overvoltage protection process includes: In the case where the current withdrawal time duration in the overvoltage protection time duration is greater than the limit time duration, the voltage deviation value is determined based on the voltage value corresponding to the excess time duration.

10. The overvoltage protection method according to claim 8, characterized in that: The preset duration includes: an over-limit duration; the over-limit duration represents the duration of the battery voltage response battery life; If the overvoltage protection duration is greater than the preset duration, determining the voltage deviation value based on the voltage value corresponding to the excessive duration during the overvoltage protection process includes: When the total over-limit duration in the overvoltage protection duration is greater than the over-limit limit duration, the voltage deviation value is determined based on the voltage value corresponding to the over-limit duration.

11. The overvoltage protection method according to claim 8, characterized in that: The preset duration includes: limit duration and over-limit limit duration; If the overvoltage protection duration is greater than the preset duration, determining the voltage deviation value based on the voltage value corresponding to the excessive duration during the overvoltage protection process includes: When the current withdrawal time is greater than the limit time, and the total exceeding time is greater than the exceeding limit time, the voltage deviation value is determined based on the voltage value corresponding to the exceeding time.

12. The overvoltage protection method according to claim 5, characterized in that: When the voltage of the battery is greater than the voltage threshold, overvoltage protection is performed, and the current withdrawal time and the overlimit time are determined; After determining the total overtime duration based on the overtime duration, the method further includes: If the total exceeding time is less than or equal to the exceeding limit time, then when the current withdrawal time is greater than the limit time, the voltage deviation value is determined based on the voltage value corresponding to the exceeding time.

13. The overvoltage protection method according to any one of claims 8 to 12, characterized in that: The voltage value corresponding to the excessive time duration is a first voltage value corresponding to each time duration node within the excessive time duration; The determining the voltage deviation value based on the voltage value corresponding to the over-limit time length includes: Determine a second voltage value corresponding to each duration node within the exceeded duration; the second voltage value is a difference between the first voltage value and the voltage threshold; Determine a total voltage value of the overrun time; the total voltage value is the sum of the second voltage values ​​corresponding to each time node; Determine the voltage deviation value; the voltage deviation value is the ratio of the total voltage value to the over-limit time duration.

14. The overvoltage protection method according to any one of claims 1 to 5, characterized in that: In response to the overvoltage protection duration being greater than the preset duration, the target voltage threshold obtained by lowering the voltage threshold is the difference between the voltage threshold and the voltage deviation value.

15. A battery management system, characterized in that: include: A controller, used for performing overvoltage protection when the voltage of the battery is greater than a voltage threshold; In response to the overvoltage protection duration being greater than a preset duration, lowering the voltage threshold; Among them, the overvoltage protection duration includes: the current withdrawal duration of the charging pile, and / or the total over-limit duration; the current withdrawal duration represents the time taken for the charging pile to start the current withdrawal operation and for the current value of the charging pile to become zero; the total over-limit duration represents the total time it takes for the battery voltage to return to the voltage threshold after exceeding the voltage threshold each time.

16. A vehicle, characterized in that: Comprising a battery management system and a battery as claimed in claim 15.

Images