Vehicle-mounted low-voltage storage battery charging state detection method and device and vehicle

Abstract

The invention provides a vehicle-mounted low-voltage storage battery charging state detection method and device and a vehicle, and the method comprises the steps: when a DC-DC converter charges a low-voltage storage battery, obtaining a first parameter corresponding to the low-voltage storage battery and a second parameter corresponding to the DC-DC converter, the first parameter being used for representing the charging condition of the low-voltage storage battery, and the second parameter being used for representing the charging condition of the low-voltage storage battery; the second parameter is used for representing the discharge condition of the DC-DC converter; determining whether a diagnosis enabling condition is met or not according to the first parameter and the second parameter; if the diagnosis enabling condition is met, the charging request current and the actual charging current of the low-voltage storage battery are accumulated, and whether the charging state of the low-voltage storage battery is normal or not is determined based on the request charging current accumulated value and the actual charging current accumulated value. By the adoption of the vehicle-mounted low-voltage storage battery charging state detection method and device and the vehicle, the problems that in the low-voltage storage battery charging state detection process, the detection mode lags behind, and the detection efficiency is low are solved.

Description

Technical Field

[0001] The present application relates to the technical field of vehicle batteries, and in particular to a method and device for detecting the charging status of a vehicle-mounted low-voltage battery, and a vehicle. Background Art

[0002] At present, the 12V power supply system of new energy vehicles usually adopts a combination of high-voltage power batteries, DC-to-DC converters, and 12V lithium (lead-acid) batteries. With the improvement of intelligence, each module has related fault detection logic, but the line connection faults between modules are easy to be overlooked. For example: when the customer modified the vehicle, he installed a line between the DC-DC converter and the 12V lithium battery, but did not tighten the screws at the output end of the DC-DC converter, resulting in the DC-DC converter only being able to charge the 12V lithium battery intermittently. However, because both the DC-DC converter and the 12V lithium battery can supply power to the vehicle's low-voltage load, the relevant faults of the vehicle were not detected in time, and finally the 12V lithium battery was exhausted.

[0003] In the prior art, after a low-voltage battery fails, a manual check is usually performed to detect whether the charging state of the low-voltage battery is normal, which results in delayed detection and low detection efficiency. Summary of the invention

[0004] In view of this, the purpose of the present application is to provide a method, device and vehicle for detecting the charging status of a vehicle-mounted low-voltage battery, so as to solve the problems of delayed detection and low detection efficiency during the detection of the charging status of a low-voltage battery.

[0005] In a first aspect, an embodiment of the present application provides a method for detecting a charging state of a vehicle-mounted low-voltage battery, comprising:

[0006] When the DC-DC converter charges the low-voltage battery, a first parameter corresponding to the low-voltage battery and a second parameter corresponding to the DC-DC converter are obtained, wherein the first parameter is used to characterize the charging condition of the low-voltage battery, and the second parameter is used to characterize the discharging condition of the DC-DC converter;

[0007] Determining whether a diagnosis enabling condition is met according to the first parameter and the second parameter;

[0008] If the diagnosis enabling condition is met, the charging request current and the actual charging current of the low-voltage battery are accumulated, and based on the accumulated value of the requested charging current and the accumulated value of the actual charging current, it is determined whether the charging state of the low-voltage battery is normal.

[0009] Optionally, the first parameter includes the charging mode, the remaining power, and the actual charging voltage; the second parameter includes the converter state, the maximum allowable output current, the output voltage and the output current; the diagnostic enable conditions include: the charging mode is the constant current charging mode, the remaining power is less than the set power threshold, the converter state is the working state, the output voltage is greater than the sum of the actual charging voltage and the voltage compensation value, and the maximum allowable output current is greater than the sum of the output current and the current compensation value.

[0010] Optionally, based on the cumulative value of requested charging current and the cumulative value of actual charging current, determine whether the charging status of the low-voltage battery is normal, including: comparing the cumulative value of requested charging current with a first set current threshold; if it is greater than the first set current threshold, comparing the cumulative value of actual charging current with a second set current threshold; if it is greater than the second set current threshold, determine that the charging status of the low-voltage battery is normal.

[0011] Optionally, after comparing the requested charging current accumulated value with the first set current threshold, it also includes: if the requested charging current accumulated value is less than or equal to the first set current threshold and the current accumulated time is equal to the set time threshold, then exiting the charging status detection for the low-voltage battery.

[0012] Optionally, after determining whether the actual charging current accumulated value is greater than the second set current threshold, it also includes: if it is less than or equal to the second set current threshold, determining that the charging state of the low-voltage battery is abnormal.

[0013] Optionally, the method further includes: comparing the current accumulated duration with a set duration threshold, and comparing the requested charging current accumulated value with a first set current threshold according to the duration comparison result.

[0014] Optionally, different remaining power levels correspond to different set time thresholds, and the set time threshold is proportional to the remaining power level.

[0015] In a second aspect, an embodiment of the present application further provides a vehicle-mounted low-voltage battery charging state detection device, the device comprising:

[0016] A parameter acquisition module, used for acquiring a first parameter corresponding to the low-voltage battery and a second parameter corresponding to the DC-DC converter when the DC-DC converter charges the low-voltage battery, wherein the first parameter is used to characterize the charging condition of the low-voltage battery, and the second parameter is used to characterize the discharging condition of the DC-DC converter;

[0017] A condition judgment module, used to determine whether a diagnosis enabling condition is met according to the first parameter and the second parameter;

[0018] The charging status detection module is used to accumulate the charging request current and the actual charging current of the low-voltage battery if the diagnosis enabling conditions are met, and determine whether the charging status of the low-voltage battery is normal based on the accumulated value of the requested charging current and the accumulated value of the actual charging current.

[0019] In a third aspect, an embodiment of the present application further provides a vehicle, including a vehicle controller, a low-voltage battery, and a DC-DC converter;

[0020] A vehicle controller, used to execute the steps of the above-mentioned method for detecting the charging state of a vehicle-mounted low-voltage battery;

[0021] A low-voltage battery, used to send a first parameter representing a charging condition of the low-voltage battery to a vehicle controller;

[0022] The DC-DC converter is used to send a second parameter representing the discharge condition of the DC-DC converter to the vehicle controller.

[0023] The embodiments of the present application bring the following beneficial effects:

[0024] The embodiments of the present application provide a method, device and vehicle for detecting the charging status of a vehicle-mounted low-voltage battery. When the DC-DC converter charges the low-voltage battery, the charging and discharging parameters of the low-voltage battery and the DC-DC converter can be obtained in real time, and whether the diagnostic enabling conditions are met according to the charging and discharging parameters. When the diagnostic enabling conditions are met, the charging status is detected using the cumulative value of the requested charging current and the cumulative value of the actual charging current. The cumulative value of the requested charging current and the cumulative value of the actual charging current can reflect the charging amount. The charging status is detected according to the charging amount, which improves the timeliness and accuracy of the detection and avoids the risk of the vehicle not being able to be used normally due to the low-voltage battery feeding. Compared with the vehicle-mounted low-voltage battery charging status detection method in the prior art, the problem of detection lag and low detection efficiency in the low-voltage battery charging status detection process is solved.

[0025] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, preferred embodiments are specifically cited below and described in detail with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0027] Figure 1 A flow chart showing a method for detecting a charging state of a vehicle-mounted low-voltage battery provided in an embodiment of the present application is shown;

[0028] Figure 2 A schematic diagram showing a normal charging state of a vehicle-mounted lithium battery provided in an embodiment of the present application;

[0029] Figure 3 A schematic diagram showing an abnormal charging state of a vehicle-mounted lithium battery provided in an embodiment of the present application is shown;

[0030] Figure 4 A schematic diagram showing the structure of a vehicle-mounted low-voltage battery charging state detection device provided in an embodiment of the present application is shown;

[0031] Figure 5 A schematic diagram of the structure of a vehicle provided in an embodiment of the present application is shown. DETAILED DESCRIPTION

[0032] To make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all of the embodiments. The components of the embodiments of the present application usually described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the application claimed for protection, but merely represents the selected embodiments of the present application. Based on the embodiments of the present application, each other embodiment obtained by those skilled in the art without making creative work belongs to the scope of protection of the present application.

[0033] It is worth noting that before the present application was proposed, the 12V power supply system of new energy vehicles generally adopts a combination of high-voltage power battery, DC-to-DC converter, and 12V lithium (lead-acid) battery. With the improvement of intelligence, each module has related fault detection logic, but the line connection fault between each module is easy to be ignored. For example: when the customer modified the vehicle, he installed a line between the DC-to-DC converter and the 12V lithium battery, but did not tighten the screws at the output end of the DC-to-DC converter, resulting in the DC-to-DC converter only being able to charge the 12V lithium battery intermittently. However, because both the DC-to-DC converter and the 12V lithium battery can supply power to the vehicle's low-voltage load, the relevant faults of the vehicle were not detected in time, and finally the 12V lithium battery was exhausted. In the prior art, it is usually to detect whether the charging state of the low-voltage battery is normal by manual troubleshooting after the low-voltage battery fails, resulting in detection lag and low detection efficiency.

[0034] Based on this, an embodiment of the present application provides a method for detecting the charging status of a vehicle-mounted low-voltage battery to improve the timeliness and efficiency of the detection of the charging status of the low-voltage battery.

[0035] See also Figure 1 , Figure 1 This is a flow chart of a method for detecting the charging status of a vehicle-mounted low-voltage battery provided in an embodiment of the present application. Figure 1 As shown, the method for detecting the charging state of a vehicle-mounted low-voltage battery provided in an embodiment of the present application includes:

[0036] Step S101, when the DC-DC converter charges the low-voltage battery, obtaining a first parameter corresponding to the low-voltage battery and a second parameter corresponding to the DC-DC converter;

[0037] Step S102, determining whether a diagnosis enabling condition is met according to the first parameter and the second parameter;

[0038] Step S103: if the diagnosis enabling condition is met, the charging request current and the actual charging current of the low-voltage battery are accumulated, and based on the accumulated value of the requested charging current and the accumulated value of the actual charging current, it is determined whether the charging state of the low-voltage battery is normal.

[0039] The on-vehicle low-voltage battery charging status detection method provided in the embodiment of the present application can obtain the charging and discharging parameters of the low-voltage battery and the DC-DC converter in real time when the DC-DC converter charges the low-voltage battery, judge whether the diagnosis enabling conditions are met according to the charging and discharging parameters, and perform charging status detection using the requested charging current cumulative value and the actual charging current cumulative value when the diagnosis enabling conditions are met. The requested charging current cumulative value and the actual charging current cumulative value can accurately reflect the charging amount, and the charging status is detected according to the charging amount, which improves the timeliness and accuracy of the detection, avoids the risk of the vehicle not being able to be used normally due to the low-voltage battery power supply, and solves the problems of detection lag and low detection efficiency in the low-voltage battery charging status detection process.

[0040] To facilitate understanding of this embodiment, the following takes the application of the vehicle low-voltage battery charging state detection method to the vehicle controller as an example to illustrate the above exemplary steps provided in the embodiment of this application. The vehicle controller may refer to a VCU (Vehicle Control Unit), and as an example, the VCU may be a Mobility Domain Control Unit (MDCU).

[0041] In step S101, when the DC-DC converter charges the low-voltage battery, a first parameter corresponding to the low-voltage battery and a second parameter corresponding to the DC-DC converter are obtained.

[0042] In this step, the DC-DC converter may refer to a DC-DC converter, and the low-voltage battery may refer to a 12V lithium battery carried by the vehicle. Both the 12V lithium battery and the DC-DC converter can provide power for the low-voltage load of the vehicle.

[0043] The first parameter is used to characterize the charging condition of the low voltage battery, and the second parameter is used to characterize the discharging condition of the DC-DC converter.

[0044] In the embodiment of the present application, the lithium battery and the DC-DC converter are both connected to the VCU, and the VCU can obtain the working status and related parameters of the lithium battery and the DC-DC converter. Here, the parameters of the lithium battery obtained by the VCU are referred to as the first parameters, and the parameters of the DC-DC converter obtained by the VCU are referred to as the second parameters.

[0045] The first parameter includes a charging mode, a requested charging current, a requested charging voltage, a remaining power, an actual charging voltage, and an actual charging current.

[0046] The charging modes include constant current charging mode and constant voltage charging mode; the requested charging current may refer to the current expected to be charged when the lithium battery sends a charging request to the DC-DC converter; the requested charging voltage may refer to the voltage corresponding to the requested charging current; the remaining power may refer to SOC (State of Charge); the actual charging current may refer to the actual external current, which is the current sensed by the sensor outside the lithium battery; the actual charging voltage may refer to the actual external voltage, which is the voltage corresponding to the actual charging current.

[0047] The second parameters include converter status, maximum allowable output current, output voltage, and output current.

[0048] The converter status includes working status, holding status, initialization status, and fault status; the output voltage may refer to the voltage actually output by the DC-DC converter; the output current may refer to the voltage actually output by the DC-DC converter; the maximum allowable output current is calculated based on the input current of the DC-DC converter.

[0049] In an embodiment of the present application, the IBS (lithium battery controller) will send the parameter value of the first parameter to the VCU, and the DC-DC converter will send the parameter value of the second parameter to the VCU, so that the VCU determines whether the diagnostic enable condition is met based on the parameter values ​​of the first parameter and the second parameter.

[0050] In step S102, it is determined whether a diagnosis enabling condition is satisfied according to the first parameter and the second parameter.

[0051] In this step, the diagnosis enabling condition may refer to a triggering condition for starting to perform charging state detection.

[0052] In one example, the diagnosis enabling conditions include: the charging mode is the constant current charging mode, the remaining power is less than the set power threshold, the DC-DC converter is in working state, the output voltage is greater than the sum of the actual charging voltage and the voltage compensation value, and the maximum allowable output current is greater than the sum of the output current and the current compensation value. For example: the charging mode requested by the 12V lithium battery is the constant current charging mode, the SOC of the 12V lithium battery is less than 90%, the state of the DC-DC converter is in working state, the output voltage of the DC-DC converter is greater than the sum of the actual charging voltage of the 12V lithium battery and the voltage compensation value, and the maximum allowable output current of the DC-DC converter is greater than the sum of the output current of the DC-DC converter and the current compensation value.

[0053] When there is a charge request for the 12V lithium battery and the above five conditions are met at the same time, it is determined that the diagnosis enabling condition is met.

[0054] In step S103, if the diagnosis enabling condition is met, the charging request current and the actual charging current of the low-voltage battery are accumulated, and based on the accumulated value of the requested charging current and the accumulated value of the actual charging current, it is determined whether the charging state of the low-voltage battery is normal.

[0055] In this step, when the diagnosis enabling condition is met, the charging request current and the actual charging current of the lithium battery are accumulated, and the accumulated time is recorded.

[0056] In one example, when determining whether the charging state of a lithium battery is normal, the cumulative value of the requested charging current and the cumulative value of the actual charging current from the accumulation start time to the current time can be continuously calculated. The cumulative value of the requested charging current is called the requested charging current cumulative value, the cumulative value of the actual charging current is called the actual charging current cumulative value, and the duration from the accumulation start time to the current time is called the current cumulative duration. At the same time, a new round of accumulation process is restarted every 3000s, and the cycle is continuous to continuously perform lithium battery charging state detection.

[0057] During a round of accumulation, the current accumulated time is first compared with the set time threshold. If the current accumulated time is less than or equal to the set time threshold, the requested charging current accumulated value is further compared with the first set current threshold; if the current accumulated time is greater than the set time threshold, it means that the accumulation time range of this round has been exceeded and the next round of detection needs to be started. At this time, the requested charging current accumulated value, the actual charging current accumulated value and the current accumulated time are cleared, and accumulation starts again.

[0058] Taking a round of lithium battery status detection process as an example, if the current cumulative duration is less than or equal to the set duration threshold, the cumulative value of the requested charging current is compared with the first set current threshold every 100ms within 3000s to determine whether the cumulative value of the requested charging current is greater than the first set current threshold. Among them, 3000s is the set duration threshold and 100ms is the comparison period.

[0059] If the cumulative value of the requested charging current is greater than the first set current threshold, it means that the cumulative value of the requested charging current meets the requested charging amount requirement, and it is necessary to further compare the actual charging current cumulative value with the second set current threshold to determine whether the charging status of the lithium battery is normal based on the comparison result.

[0060] If the cumulative value of the requested charging current is less than or equal to the first set current threshold, it means that the cumulative value of the requested charging current does not meet the requested charging amount requirement. At this time, it is necessary to determine how to perform subsequent processing based on the specific comparison result between the current cumulative duration and the set duration threshold. In one case, if the current cumulative duration is less than the set duration threshold and the cumulative value of the requested charging current is less than or equal to the first set current threshold, the current cumulative duration, actual charging current and requested charging current will continue to be accumulated. In another case, if the current cumulative duration is equal to the set duration threshold and the cumulative value of the requested charging current is less than or equal to the first set current threshold, it means that the cumulative value of the requested charging current is small and does not meet the diagnostic reliability requirements, then the charging status detection for the lithium battery is exited.

[0061] When comparing the actual charging current accumulated value with the second set current threshold, if the actual charging current accumulated value is greater than the second set current threshold, it means that the actual charging amount of the lithium battery meets the requirements, and it is determined that the charging state of the lithium battery is normal. Figure 2 The following is a data curve showing the actual charging current accumulated value and the requested charging current accumulated value when the lithium battery is in normal charging state.

[0062] Figure 2 A schematic diagram showing a normal charging state of the vehicle-mounted lithium battery provided in an embodiment of the present application is shown. Figure 2 As shown in the figure, this is a normal charging data diagram of a 12V battery. As the current cumulative time continues to increase, the SOC continues to increase, indicating that the lithium battery is in a normal charging state. At this time, the requested charging current remains basically unchanged, and the cumulative requested charging power increases linearly. The cumulative requested charging power is the cumulative value of the requested charging current. The actual charging current is constantly changing around the requested charging current, and the cumulative actual charging power also increases linearly. The cumulative actual charging power is the actual charging current.

[0063] On the contrary, if it is less than or equal to the second set current threshold, it means that the actual charging capacity of the lithium battery does not meet the requirements, and it is determined that the charging state of the lithium battery is abnormal. Figure 3 The following is a data curve showing the actual charging current accumulated value and the requested charging current accumulated value when the lithium battery charging status is abnormal.

[0064] Figure 3 A schematic diagram showing an abnormal charging state of a vehicle-mounted lithium battery provided in an embodiment of the present application is shown. Figure 3 As shown in the figure, this is a 12V battery abnormal charging data diagram. As the current cumulative time continues to increase, the SOC remains unchanged, indicating that the lithium battery is in an abnormal charging state. At this time, the requested charging current and the actual charging current remain basically unchanged, and the cumulative requested charging capacity increases linearly. The cumulative requested charging capacity is the cumulative value of the requested charging current. However, the cumulative actual charging capacity does not increase linearly, and the cumulative actual charging capacity is the actual charging current.

[0065] In one example, under different SOCs, the current requested by the lithium battery controller to the DC-DC converter is different. The requested charging current is higher under low SOC, and lower under high SOC. To this end, different remaining power corresponds to different set time thresholds, and the set time threshold is proportional to the remaining power. The higher the remaining power, the higher the set time threshold; the lower the remaining power, the lower the set time threshold; so that the 12V lithium battery can detect faults faster at low SOC, and have a longer judgment time at high SOC, improving diagnostic reliability.

[0066] Based on the same inventive concept, an on-vehicle low-voltage battery charging status detection device corresponding to the on-vehicle low-voltage battery charging status detection method is also provided in the embodiment of the present application. Since the principle of solving the problem by the device in the embodiment of the present application is similar to the above-mentioned on-vehicle low-voltage battery charging status detection method in the embodiment of the present application, the implementation of the device can refer to the implementation of the method, and the repeated parts will not be repeated.

[0067] See also Figure 4 , Figure 4 This is a schematic diagram of the structure of a vehicle-mounted low-voltage battery charging status detection device provided in an embodiment of the present application. Figure 4 As shown in the figure, the vehicle-mounted low-voltage battery charging state detection device 200 includes:

[0068] The parameter acquisition module 201 is used to acquire a first parameter corresponding to the low-voltage battery and a second parameter corresponding to the DC-DC converter when the DC-DC converter charges the low-voltage battery, wherein the first parameter is used to characterize the charging condition of the low-voltage battery, and the second parameter is used to characterize the discharging condition of the DC-DC converter;

[0069] A condition determination module 202, configured to determine whether a diagnosis enabling condition is met according to a first parameter and a second parameter;

[0070] The charging status detection module 203 is used to accumulate the charging request current and the actual charging current of the low-voltage battery if the diagnosis enabling condition is met, and determine whether the charging status of the low-voltage battery is normal based on the accumulated value of the requested charging current and the accumulated value of the actual charging current.

[0071] See also Figure 5 , Figure 5 This is a schematic diagram of the structure of a vehicle provided in an embodiment of the present application. Figure 5 As shown in , the vehicle 300 includes a vehicle controller 310 , a low-voltage battery 320 and a DC-DC converter 330 .

[0072] The vehicle controller 310 is used to execute the above Figure 1 The steps of the method for detecting the charging state of a vehicle-mounted low-voltage battery in the method embodiment shown;

[0073] The low-voltage battery 320 is used to send a first parameter representing the charging status of the low-voltage battery to the vehicle controller;

[0074] The DC-DC converter 330 is used to send a second parameter representing the discharge condition of the DC-DC converter to the vehicle controller.

[0075] The present application also provides a computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, the computer program can execute the above-mentioned Figure 1 The steps of the method for detecting the charging status of a vehicle-mounted low-voltage battery in the method embodiment shown in the embodiment and the specific implementation thereof can be referred to the method embodiment, which will not be described in detail here.

[0076] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0077] 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 merely schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some communication interfaces, and the indirect coupling or communication connection of devices or units can be electrical, mechanical or other forms.

[0078] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0079] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0080] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a non-volatile computer-readable storage medium that is executable by a processor. Based on this understanding, the technical solution of the present application can essentially be embodied in the form of a software product, or in other words, the part that contributes to the prior art or the part of the technical solution. The computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0081] Finally, it should be noted that the above-described embodiments are only specific implementation methods of the present application, which are used to illustrate the technical solutions of the present application, rather than to limit them. The protection scope of the present application is not limited thereto. Although the present application is described in detail with reference to the above-mentioned embodiments, ordinary technicians in the field should understand that any technician familiar with the technical field can still modify the technical solutions recorded in the above-mentioned embodiments within the technical scope disclosed in the present application, or can easily think of changes, or make equivalent replacements for some of the technical features therein; and these modifications, changes or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A method for detecting the charging state of a vehicle-mounted low-voltage battery, characterized in that: include: When the DC-DC converter charges the low-voltage battery, obtaining a first parameter corresponding to the low-voltage battery and a second parameter corresponding to the DC-DC converter, wherein the first parameter is used to characterize the charging condition of the low-voltage battery, and the second parameter is used to characterize the discharging condition of the DC-DC converter; Determining whether a diagnosis enabling condition is met according to the first parameter and the second parameter; If the diagnosis enabling condition is met, the charging request current and the actual charging current of the low-voltage battery are accumulated, and based on the accumulated value of the requested charging current and the accumulated value of the actual charging current, it is determined whether the charging state of the low-voltage battery is normal.

2. The method according to claim 1, characterized in that: The first parameter includes a charging mode, a remaining power, and an actual charging voltage; the second parameter includes a converter state, a maximum allowable output current, an output voltage, and an output current; and the diagnostic enabling conditions include: the charging mode is a constant current charging mode, the remaining power is less than a set power threshold, the converter state is a working state, the output voltage is greater than the sum of the actual charging voltage and a voltage compensation value, and the maximum allowable output current is greater than the sum of the output current and a current compensation value.

3. The method according to claim 1, characterized in that The step of determining whether the charging state of the low-voltage battery is normal based on the requested charging current accumulated value and the actual charging current accumulated value includes: Comparing the requested charging current accumulated value with a first set current threshold; If it is greater than the first set current threshold, comparing the actual charging current accumulated value with the second set current threshold; If it is greater than the second set current threshold, it is determined that the charging state of the low-voltage battery is normal.

4. The method according to claim 3, characterized in that After comparing the requested charging current accumulated value with the first set current threshold, the method further includes: If the requested charging current accumulated value is less than or equal to the first set current threshold and the current accumulated time is less than the set time threshold, the current accumulated time, the actual charging current and the requested charging current continue to be accumulated.

5. The method according to claim 3, characterized in that: After comparing the requested charging current accumulated value with the first set current threshold, the method further includes: If the cumulative value of the requested charging current is less than or equal to the first set current threshold and the current cumulative duration is equal to the set duration threshold, the charging state detection for the low-voltage battery is exited.

6. The method according to claim 3, characterized in that: After determining whether the actual charging current accumulated value is greater than the second set current threshold, the method further includes: If it is less than or equal to the second set current threshold, it is determined that the charging state of the low-voltage battery is abnormal.

7. The method according to claim 3, characterized in that The method further comprises: The current accumulated time is compared with the set time threshold, so as to compare the requested charging current accumulated value with the first set current threshold according to the time comparison result.

8. The method according to claim 4 or 5, characterized in that: Different remaining power levels correspond to different set time thresholds, and the set time thresholds are proportional to the remaining power levels.

9. A vehicle-mounted low-voltage battery charging state detection device, characterized in that: include: A parameter acquisition module, used for acquiring a first parameter corresponding to the low-voltage battery and a second parameter corresponding to the DC-DC converter when the DC-DC converter charges the low-voltage battery, wherein the first parameter is used to characterize the charging condition of the low-voltage battery, and the second parameter is used to characterize the discharging condition of the DC-DC converter; A condition judgment module, used for determining whether a diagnosis enabling condition is met according to the first parameter and the second parameter; The charging status detection module is used to accumulate the charging request current and the actual charging current of the low-voltage battery if the diagnosis enabling condition is met, and determine whether the charging status of the low-voltage battery is normal based on the cumulative value of the requested charging current and the cumulative value of the actual charging current.

10. A vehicle, characterized in that: Including vehicle controller, low voltage battery and DC-DC converter; The vehicle controller is used to perform the steps of the vehicle-mounted low-voltage battery charging state detection method according to any one of claims 1 to 8; The low-voltage battery is used to send a first parameter representing the charging status of the low-voltage battery to the vehicle controller; The DC-DC converter is used to send a second parameter representing the discharge condition of the DC-DC converter to the vehicle controller.

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