Method for output abnormality diagnosis of a dc / dc converter, dc / dc device and computer program product
By collecting the output current and voltage difference of the DC/DC converter, abnormalities are diagnosed, solving the problem of difficult-to-diagnose DC/DC converter output abnormalities, achieving efficient and accurate abnormality diagnosis, and avoiding excessive power consumption.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- BOSCH AUTOMOTIVE SYSTEMS (WUXI) CO LTD
- Filing Date
- 2025-01-06
- Publication Date
- 2026-07-07
AI Technical Summary
In the existing technology, it is difficult to diagnose the output abnormality of DC/DC converters in a timely manner, causing the vehicle's low-voltage power supply network to continue to consume battery power until the battery is low enough to restart charging, resulting in excessive power consumption.
By collecting the output current of the DC/DC converter and identifying sudden current drops, and combining the target output voltage with the difference between the collected positive output voltage, the output abnormalities of the DC/DC converter can be quickly diagnosed. The abnormalities can be diagnosed using the rate of change of current and the voltage difference, thus avoiding excessive power consumption.
It enables efficient and accurate diagnosis of DC/DC converter output abnormalities, avoiding excessive battery power consumption during abnormal situations and improving the efficiency and accuracy of diagnosis.
Smart Images
Figure CN122345809A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of DC / DC converters, and more particularly to a method for diagnosing output anomalies in a DC / DC converter, a DC / DC device, and a computer program product for at least assisting in implementing the steps of the method according to this application. Background Technology
[0002] In the power supply network of electric vehicles, a DC / DC converter transforms the high voltage of the power battery into a low voltage to charge the battery and / or supply power to low-voltage components. For example... Figure 1 The diagram shown is a partial schematic of an on-board power supply network according to the prior art. The positive output terminal B+ of the DC / DC converter 11 is connected to the positive terminal of the battery 2, and the negative output terminal B- of the DC / DC converter 11 is connected to the negative terminal of the battery 2. Since the positive output terminal B+ of the DC / DC converter 11 remains connected to the positive terminal of the battery 2, when the DC / DC converter 11 malfunctions and stops outputting power, the positive output voltage U of the DC / DC converter 11... B+ The voltage remains equal to the positive terminal voltage of battery 2 (e.g., 24V), making it difficult to diagnose abnormalities in the output of DC / DC converter 11 in a timely manner. The vehicle's low-voltage power supply network continues to consume the electrical energy of battery 2 until a power failure occurs when battery 2 is low, at which point the charging process for battery 2 can be restarted.
[0003] Therefore, how to efficiently and accurately diagnose output abnormalities of DC / DC converters has become a technical challenge that needs to be solved. Summary of the Invention
[0004] The purpose of this application is to provide a method for diagnosing output anomalies in a DC / DC converter, a DC / DC device, and a computer program product, to at least partially solve the problems in the prior art.
[0005] According to a first aspect of this application, a method for diagnosing output anomalies in a DC / DC converter is provided, the method comprising:
[0006] - Acquire the output current of the DC / DC converter under vehicle operating conditions and determine whether a sudden drop in output current occurs; and
[0007] - In the event of a sudden drop in output current, the output abnormality of the DC / DC converter is diagnosed based on the target output voltage of the DC / DC converter and the acquired positive output voltage of the DC / DC converter.
[0008] The core concept of this application is to quickly eliminate the long-term low-power operation of the vehicle's low-voltage power supply network by using the collected output current of the DC / DC converter. When the output current drops sharply, the difference between the target output voltage of the DC / DC converter and the collected positive output voltage can be used to diagnose the output abnormality of the DC / DC converter efficiently, accurately and with low technical overhead, thereby avoiding excessive consumption of battery power when the DC / DC converter output is abnormal.
[0009] According to a second aspect of this application, a DC / DC device is provided, which may include the following components:
[0010] -DC / DC converter;
[0011] - Current acquisition unit, which is configured to acquire the output current of the DC / DC converter;
[0012] - Voltage acquisition unit, which is configured to acquire the positive output voltage of the DC / DC converter;
[0013] and
[0014] - A control unit configured to perform the method according to this application.
[0015] According to a third aspect of this application, a computer program product, such as a computer-readable program carrier, is provided, comprising computer program instructions that, when executed by a processor, at least assist in implementing the steps of the method according to this application. Attached Figure Description
[0016] The principles, features, and advantages of this application will be better understood below with reference to the accompanying drawings. The drawings include:
[0017] Figure 1 A partial schematic diagram of an on-board power supply network according to the prior art is shown;
[0018] Figure 2 A flowchart illustrating a method for diagnosing output anomalies in a DC / DC converter according to an exemplary embodiment of this application is shown.
[0019] Figure 3 A flowchart illustrating a method for diagnosing output anomalies in a DC / DC converter according to another exemplary embodiment of this application is shown; and
[0020] Figure 4 A schematic diagram of the structure of a DC / DC device according to an exemplary embodiment of this application is shown. Detailed Implementation
[0021] To make the technical problems to be solved, the technical solutions, and the beneficial technical effects of this application clearer, the application will be further described in detail below with reference to the accompanying drawings and several exemplary embodiments. It should be understood that the specific embodiments described herein are only for explaining this application and are not intended to limit the scope of protection of this application.
[0022] Figure 2 A flowchart illustrating a method for diagnosing output anomalies in a DC / DC converter according to an exemplary embodiment of this application is shown. The following exemplary embodiments describe the method according to this application in more detail.
[0023] like Figure 2 As shown, the method may include steps S1 and S2. In step S1, the output current of the DC / DC converter 11 is acquired under the vehicle's operating conditions, and it is determined whether a sudden drop in the output current occurs. In the current embodiment of this application, the DC / DC converter 11 can step down the high voltage of the power battery, for example, several hundred volts, to a low voltage for charging, for example, a 24V battery 2, and / or for supplying power to low-voltage vehicle electrical appliances. The DC / DC converter 11 can be configured as a Buck converter or a Buck-Boost converter and operate in buck mode. Figure 4 The schematic diagram shown illustrates the structure of a DC / DC device 1 according to an exemplary embodiment of this application. The positive output terminal B+ of the DC / DC converter 11 is connected to the positive terminal of, for example, a 24V battery 2, and the negative output terminal B- of the DC / DC converter 11 is connected to the negative terminal of the battery 2. The negative voltage of the battery 2 is set to a reference voltage of 0V, and the negative output voltage of the DC / DC converter 11 is also set to a reference voltage of 0V. Under normal operating conditions, the positive output voltage U of the DC / DC converter 11 is... B+ The voltage typically varies within the range of 18V to 32V. Here, a current acquisition unit 12—for example, a current sensor—can be set at the positive output terminal B+ of the DC / DC converter 11 to acquire the output current of the DC / DC converter 11.
[0024] In the context of this application, "current sag" refers to a significant drop in the output current of the DC / DC converter 11 over a short period of time. This current sag occurs when components of the DC / DC converter 11 are de-energized—for example, when one or more power switching devices of the DC / DC converter 11 are shut off due to a fault, and / or when components connected to the DC / DC converter 11 are de-energized—for example, when there is an open circuit or poor contact in the wiring between the components in the DC / DC device 1. Under most operating conditions of the vehicle, the power demand of the on-board low-voltage power supply network is high, and the output current of the DC / DC converter 11 will be much higher than 2A; while under operating conditions where the power demand of the battery 2 and / or low-voltage on-board electrical appliances is low, the output current of the DC / DC converter 11 will be kept at a low level for a long time—for example, below 2A.
[0025] Here, the following method can be used to determine whether a sudden drop in output current has occurred: When the collected output current is lower than a pre-defined current threshold (e.g., 2A), the rate of change of the collected output current with respect to time can be calculated. Specifically, the change in the collected output current within each defined fixed time interval can be determined. When the output current decreases, the rate of change of the output current with respect to time is negative; the lower the rate of change, the faster the output current decreases. If the calculated rate of change is lower than a pre-defined rate of change threshold—which is set to negative—this means the output current is decreasing at a relatively rapid rate, indicating a sudden drop in output current. This allows for the quick and accurate exclusion of prolonged low-power operation conditions in the vehicle's low-voltage power supply network, as the output current is maintained at a low level for extended periods under such conditions.
[0026] In step S2, if a sudden drop in the output current occurs, the target output voltage U of the DC / DC converter 11 can be used as a reference. t The positive output voltage U of the acquired DC / DC converter 11 B+ Diagnose output abnormalities in DC / DC converter 11. Here, the target output voltage U of the DC / DC converter 11 is... tThe target output voltage U of the battery 2, which is powered by the DC / DC converter 11, can be determined by the upper-level system 3 (e.g., the vehicle controller) based on the vehicle's operating conditions and / or characteristic parameters of the battery 2. These characteristic parameters include, for example, the battery 2's state of health, state of charge, and / or open-circuit voltage. For instance, during vehicle startup, the battery 2, which has a low state of charge, needs to be charged via the DC / DC converter 11. Based on the battery 2's state of health, state of charge, and / or open-circuit voltage, the charging voltage and charging power of the battery 2 can be determined. Simultaneously, power is supplied to low-voltage vehicle electrical components—such as the starter motor, ignition system, and lighting devices—thereby determining the target output voltage U of the DC / DC converter 11. t For example, it is 28V.
[0027] like Figure 4 The schematic diagram of the DC / DC device 1 shown illustrates that after the vehicle is powered on, the upper-level system 3 will output the determined target voltage U. t The data is transmitted to the control unit 14 of the DC / DC device 1. A voltage acquisition unit 13—for example, a voltage sensor—can be installed at the positive output terminal B+ of the DC / DC converter 11, configured to acquire the positive output voltage U of the DC / DC converter 11. B+ .
[0028] Here, the target output voltage U of the DC / DC converter 11 can be calculated. t The positive output voltage U of the acquired DC / DC converter 11 B+ The difference. Under normal operating conditions of DC / DC converter 11, the target output voltage U of DC / DC converter 11. t Maintain the positive output voltage U of the acquired DC / DC converter 11 B+ —That is, both are equal to 28V, and the difference between them is zero. When the DC / DC converter 11 stops outputting power due to a fault at a certain moment, since the positive output terminal B+ of the DC / DC converter 11 remains connected to the positive terminal of the battery 2, the collected positive output voltage U of the DC / DC converter 11... B+ Equal to the positive terminal voltage of battery 2—that is, 24V, the target output voltage U t With positive output voltage U B+ The difference is equal to 4V. If the calculated difference exceeds a pre-defined voltage difference threshold—for example, 3V—it can be diagnosed that the DC / DC converter 11 has an output abnormality.
[0029] According to the current embodiment of this application, the long-term low-power operation of the vehicle low-voltage power supply network can be quickly eliminated by using the collected output current of the DC / DC converter. In the event of a sudden drop in output current, the output abnormality of the DC / DC converter can be diagnosed efficiently, accurately and with low technical overhead based on the difference between the target output voltage of the DC / DC converter and the collected positive output voltage, thereby avoiding excessive consumption of battery power when the DC / DC converter output is abnormal.
[0030] Figure 3 A flowchart illustrating a method for diagnosing output anomalies in a DC / DC converter according to another exemplary embodiment of this application is shown. The following only describes the method in relation to... Figure 2 The differences between the embodiments shown are omitted for brevity, and the same steps will not be repeated.
[0031] like Figure 3 As shown, the method may further include step S3. In step S3, if an output abnormality is diagnosed in the DC / DC converter 11, diagnostic information regarding the output abnormality of the DC / DC converter 11 can be sent. Here, the control unit 14 of the DC / DC device 1 can send the diagnostic information to the upper-level system 3 (e.g., the vehicle controller). The diagnostic information may include not only first diagnostic information regarding the output abnormality of the DC / DC converter, but also second diagnostic information regarding the cause of the fault in the DC / DC converter. Exemplarily, this may be based at least on the acquired output current and the target output voltage U of the DC / DC converter 11. t And / or the positive output voltage U of the acquired DC / DC converter 11 B+ The causes of output abnormalities in the DC / DC converter 11 are determined, and the correspondence between these causes and parameters can be pre-stored in the control unit 14, for example, in the form of a lookup table. Upon receiving the diagnostic information, the upper-level system 3 can take appropriate countermeasures based on the causes of the faults.
[0032] In addition, it should be noted that the step numbers described herein do not necessarily represent the order of steps, but are merely a reference numeral. The order may be changed depending on the specific circumstances, as long as the technical objective of this application can be achieved.
[0033] Figure 4 A schematic diagram of the structure of a DC / DC device according to an exemplary embodiment of this application is shown.
[0034] like Figure 4 As shown, the DC / DC device 1 may include the following components:
[0035] -DC / DC converter 11, which can be configured as a Buck converter or a Buck-Boost converter and operate in buck mode, for charging battery 2 and / or powering low-voltage vehicle electrical appliances (not shown);
[0036] - Current acquisition unit 12, which is configured to acquire the output current of DC / DC converter 11, for example, configured as a current sensor at the positive output terminal B+ of DC / DC converter 11;
[0037] - Voltage acquisition unit 13, which is configured to acquire the positive output voltage U of DC / DC converter 11 B+ For example, configured as the positive output terminal B+ of DC / DC converter 11
[0038] Voltage sensor at the location; and
[0039] - Control unit 14, configured to perform the method according to this application, wherein the control unit 14 can obtain the target output voltage U of the DC / DC converter 11 from the upper-level system 3 (e.g., vehicle controller). t .
[0040] It should be understood that in this document, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance, nor should they be construed as implicitly specifying the number of technical features indicated.
[0041] If an embodiment includes an "and / or" association between a first feature and a second feature, it should be interpreted as follows: according to one implementation, the embodiment has not only the first feature but also the second feature; according to another implementation, the embodiment has either only the first feature or only the second feature.
[0042] Although specific embodiments have been described above, these embodiments are not intended to limit the scope of this application, even when only a single embodiment is described with respect to a particular feature. The feature examples provided in this application are intended for illustrative purposes and not for limitation, unless otherwise stated. In practice, multiple features may be combined with each other as needed and where technically feasible. Various substitutions, modifications, and alterations are also conceived without departing from the spirit and scope of this application.
Claims
1. A method for diagnosing output anomalies in a DC / DC converter (11), the method comprising: The output current of the DC / DC converter (11) is collected under the vehicle's operating conditions, and it is determined whether the output current experiences a sudden drop. as well as In the event of a sudden drop in output current, the output abnormality of the DC / DC converter (11) is diagnosed based on the target output voltage of the DC / DC converter (11) and the acquired positive output voltage of the DC / DC converter (11).
2. The method according to claim 1, wherein, The difference between the target output voltage of the DC / DC converter (11) and the positive output voltage of the DC / DC converter (11) is calculated. If the calculated difference exceeds a pre-given voltage difference threshold, the DC / DC converter (11) is diagnosed as having an output abnormality.
3. The method according to claim 1 or 2, wherein, The following method is used to determine whether the output current has experienced a sudden drop: if the collected output current is lower than a pre-defined current threshold, the rate of change of the collected output current with respect to time is calculated. If the calculated rate of change is lower than a pre-defined rate of change threshold, then the output current has experienced a sudden drop.
4. The method according to any one of claims 1 to 3, wherein, The method further includes: If the output of the DC / DC converter (11) is diagnosed as abnormal, diagnostic information about the output abnormality of the DC / DC converter (11) is sent to the upper-level system (3).
5. The method according to any one of claims 1 to 4, wherein, The target output voltage of the DC / DC converter (11) is determined based on the vehicle's operating conditions and / or the characteristic parameters of the battery (2) powered by the DC / DC converter (11), wherein the characteristic parameters include the battery (2)'s health status, state of charge, and / or open-circuit voltage.
6. The method according to any one of claims 1 to 5, wherein, When the components of the DC / DC converter (11) and / or the components connected to the DC / DC converter (11) are de-energized, the output current of the DC / DC converter (11) experiences a sudden drop.
7. The method according to claim 4, wherein, The diagnostic information includes first diagnostic information about the output abnormality of the DC / DC converter, and / or second diagnostic information about the cause of the fault in the DC / DC converter output abnormality.
8. The method according to claim 7, wherein, The cause of the output abnormality of the DC / DC converter (11) can be determined at least based on the acquired output current, the target output voltage of the DC / DC converter (11) and / or the acquired positive output voltage of the DC / DC converter (11).
9. A DC / DC device (1), the DC / DC device (1) comprising the following components: DC / DC converter (11); A current acquisition unit (12) is configured to acquire the output current of the DC / DC converter (11); A voltage acquisition unit (13) is configured to acquire the positive output voltage of the DC / DC converter (11); and Control unit (14) configured to perform the method according to any one of claims 1 to 8.
10. A computer program product, such as a computer-readable program carrier, comprising computer program instructions that, when executed by a processor, at least partially implement the steps of the method according to any one of claims 1 to 8.