Relay adhesion diagnosis method, device and system

Abstract

The present application discloses a relay adhesion diagnosis method, device and system, wherein the circuit to be detected includes at least a battery pack and a relay to be tested, and the battery pack and the relay to be tested are connected in series; the relay adhesion diagnosis method includes: detecting a first voltage at both ends of the battery pack, and detecting a second voltage at both ends of the battery pack and the relay to be tested in series; when the absolute value of the voltage difference between the first voltage and the second voltage is less than the first voltage threshold and lasts for a first preset time, obtaining a threshold voltage combination corresponding to the first voltage and the second voltage collected within the preset diagnosis time; when the threshold voltage combination corresponding to the first voltage and the second voltage within the preset diagnosis time satisfies a preset relationship, determining that the relay to be tested is in a adhesion state. In this way, the robustness of relay adhesion diagnosis can be improved, and the problem of false positive adhesion can be avoided.

Description

Technical Field

[0001] The present application relates to the technical field of relay diagnosis, and in particular to a relay adhesion diagnosis method, device and system. Background Art

[0002] In electric vehicles, relays are used to control the opening and closing of high-voltage circuits. In order to ensure the safety of high-voltage circuits, it is usually necessary to detect whether the relay is sticking before closing the relay. The technology used for detection here is relay diagnostic technology.

[0003] However, the detection circuits in the related art are basically implemented by voltage detection. However, in some cases, the sampled voltage may drop slowly, which may easily misreport the relay adhesion fault during voltage detection, and the robustness of adhesion diagnosis is poor, resulting in misjudgment. Summary of the invention

[0004] The present application proposes a relay adhesion diagnosis method, device and system, which can improve the robustness of relay adhesion diagnosis and avoid the problem of misjudgment of adhesion.

[0005] The technical solution of this application is implemented as follows:

[0006] In a first aspect, an embodiment of the present application provides a relay adhesion diagnosis method, which is applied to a circuit to be detected, wherein the circuit to be detected includes at least a battery pack and a relay to be tested, and the battery pack and the relay to be tested are connected in series; the relay adhesion diagnosis method includes:

[0007] Detecting a first voltage across the battery pack, and detecting a second voltage across the battery pack connected in series with a relay to be tested;

[0008] When the absolute value of the voltage difference between the first voltage and the second voltage is less than the first voltage threshold and lasts for a first preset time, obtaining a threshold voltage combination corresponding to the first voltage and the second voltage collected within a preset diagnosis time;

[0009] When a threshold voltage combination corresponding to the first voltage and the second voltage within a preset diagnosis time satisfies a preset relationship, determining that the relay to be tested is in a sticking state;

[0010] Wherein, the threshold voltage combination includes: the maximum value of the first voltage, the minimum value of the first voltage, the maximum value of the second voltage, and the minimum value of the second voltage;

[0011] Alternatively, the threshold voltage combination includes: a maximum voltage difference between the first voltage and the second voltage and a minimum voltage difference between the first voltage and the second voltage;

[0012] Alternatively, the threshold voltage combination includes: an initial value of the first voltage and an initial value of the second voltage collected at the start time of the preset diagnosis time, and an end value of the first voltage and an end value of the second voltage collected at the end time of the preset diagnosis time.

[0013] Through the above-mentioned technical means, after detecting the first voltage at both ends of the battery pack and the second voltage at both ends of the battery pack and the battery pack to be tested in series, it is judged whether the relay to be tested is stuck according to the size of the first voltage and the second voltage. First, a preliminary judgment is made based on whether the absolute value of the voltage difference between the first voltage and the second voltage is less than the first voltage threshold and lasts for a first preset time. Then, a further judgment is made based on whether the threshold voltage combination corresponding to the first voltage and the second voltage collected within the preset diagnosis time satisfies the preset relationship. In this way, if the absolute value of the voltage difference between the first voltage and the second voltage is less than the first voltage threshold and lasts for the first preset time, and the threshold voltage combination corresponding to the first voltage and the second voltage collected within the preset diagnosis time satisfies the preset relationship, then it can be determined that the relay to be tested is in a sticking state, thereby improving the accuracy of the relay sticking diagnosis, and timely taking remedial measures when a relay sticking fault is detected. Moreover, the double judgment can also improve the robustness of the relay sticking diagnosis, avoid the problem of misjudgment of sticking, and thereby improve the circuit reliability.

[0014] In some embodiments, the preset diagnostic time includes N detection times, and the relay adhesion diagnosis method also includes: obtaining a threshold voltage combination corresponding to the first voltage and the second voltage collected within the i-th detection time; when the threshold voltage combination corresponding to the first voltage and the second voltage within the i-th detection time does not satisfy a preset relationship, determining that the relay to be tested is in a non-adhesion state; when the threshold voltage combination corresponding to the first voltage and the second voltage within the i-th detection time satisfies a preset relationship, performing an i plus one operation until the threshold voltage combination corresponding to the first voltage and the second voltage within N detection times all satisfy the preset relationship, determining that the relay to be tested is in a adhesion state; wherein N is a positive integer, and i is an integer greater than or equal to 1 and less than or equal to N.

[0015] Through the above technical means, taking the i-th detection time as an example, if the threshold voltage combination corresponding to the first voltage and the second voltage collected during the detection time does not satisfy the preset relationship, it can be determined that the relay to be tested is in a non-adhesion state, and the relay adhesion diagnosis process is directly exited at this time; otherwise, if the threshold voltage combination corresponding to the first voltage and the second voltage collected during the detection time satisfies the preset relationship, then continue to judge whether the threshold voltage combination corresponding to the first voltage and the second voltage collected during the next detection time satisfies the preset relationship, until the threshold voltage combination corresponding to the first voltage and the second voltage in N detection times all satisfies the preset relationship, then it is determined that the relay to be tested is in a adhesion state. Therefore, multiple quick inspections can be performed within the preset diagnosis time, which can not only shorten the diagnosis time and realize adaptive quick detection, but also timely detect whether the relay has an adhesion failure. At the same time, double judgment can also avoid the problem of misjudgment of adhesion.

[0016] In some embodiments, the relay adhesion diagnosis method also includes: determining a first difference between the maximum value of the first voltage and the minimum value of the first voltage within the i-th detection time and a second difference between the maximum value of the second voltage and the minimum value of the second voltage; when the absolute value of the first voltage difference between the first difference and the second difference is less than the second voltage threshold, determining that the threshold voltage combination corresponding to the first voltage and the second voltage within the i-th detection time satisfies a preset relationship; when the absolute value of the first voltage difference between the first difference and the second difference is greater than the second voltage threshold, determining that the threshold voltage combination corresponding to the first voltage and the second voltage within the i-th detection time does not satisfy the preset relationship.

[0017] Through the above-mentioned technical means, still taking the i-th detection time as an example, when the threshold voltage combination includes the maximum value of the first voltage, the minimum value of the first voltage, the maximum value of the second voltage and the minimum value of the second voltage, whether the threshold voltage combination corresponding to the first voltage and the second voltage within the detection time satisfies the preset relationship can be first determined. The first difference between the maximum value of the first voltage and the minimum value of the first voltage and the second difference between the maximum value of the second voltage and the minimum value of the second voltage within the detection time, and then determined according to whether the absolute value of the first voltage difference between the first difference and the second difference is less than the second voltage threshold; in this way, when the absolute value of the first voltage difference between the first difference and the second difference is greater than the second voltage threshold, it indicates that the threshold voltage combination does not satisfy the preset relationship, then it can be determined that the relay to be tested is in a non-sticking state, and the relay sticking diagnosis process can be directly exited at this time, so that multiple quick inspections can be performed within the preset diagnosis time, and adaptive quick detection can be achieved, so as to detect whether the relay has a sticking failure in time.

[0018] In some embodiments, the relay adhesion diagnosis method also includes: determining the maximum voltage difference between the first voltage and the second voltage and the minimum voltage difference between the first voltage and the second voltage collected within the i-th detection time; when the absolute value of the second voltage difference between the maximum voltage difference and the minimum voltage difference is less than the second voltage threshold, determining that the threshold voltage combination corresponding to the first voltage and the second voltage within the i-th detection time satisfies a preset relationship; when the absolute value of the second voltage difference between the maximum voltage difference and the minimum voltage difference is greater than the second voltage threshold, determining that the threshold voltage combination corresponding to the first voltage and the second voltage within the i-th detection time does not satisfy the preset relationship.

[0019] Through the above-mentioned technical means, still taking the i-th detection time as an example, when the threshold voltage combination includes the maximum voltage difference between the first voltage and the second voltage and the minimum voltage difference between the first voltage and the second voltage, whether the threshold voltage combination corresponding to the first voltage and the second voltage within the detection time satisfies the preset relationship can be first determined according to the maximum voltage difference between the first voltage and the second voltage and the minimum voltage difference between the first voltage and the second voltage collected within the detection time, and then determined according to whether the absolute value of the second voltage difference between the maximum voltage difference and the minimum voltage difference is less than the second voltage threshold value; in this way, when the absolute value of the second voltage difference between the maximum voltage difference and the minimum voltage difference is greater than the second voltage threshold value, it indicates that the threshold voltage combination does not satisfy the preset relationship, then it can also be determined that the relay to be tested is in a non-sticking state, and at this time, the relay sticking diagnosis process can be directly exited, so that multiple quick inspections can be performed within the preset diagnosis time, and adaptive quick detection can be achieved, so as to timely detect whether the relay has a sticking failure.

[0020] In some embodiments, the relay adhesion diagnosis method also includes: when the absolute value of the voltage difference between the first voltage and the second voltage is less than a first voltage threshold and lasts for a first preset time, obtaining the initial value of the first voltage and the initial value of the second voltage collected at the start time of the preset diagnosis time, and the ending value of the first voltage and the ending value of the second voltage collected at the end time of the preset diagnosis time; when the initial value of the first voltage, the ending value of the first voltage, the initial value of the second voltage and the ending value of the second voltage within the preset diagnosis time satisfy a preset relationship, it is determined that the relay to be tested is in a adhesion state.

[0021] Through the above technical means, when the threshold voltage combination includes the initial value of the first voltage and the initial value of the second voltage collected at the start time of the preset diagnosis time, and the end value of the first voltage and the end value of the second voltage collected at the end time of the preset diagnosis time, when it is detected that the absolute value of the voltage difference between the first voltage and the second voltage is less than the first voltage threshold and lasts for the first preset time, it is determined that the relay to be tested may be stuck; then the first voltage and the second voltage corresponding to the start time and the end time of the preset diagnosis time are obtained (that is, the four values ​​of the initial value of the first voltage, the end value of the first voltage, the initial value of the second voltage and the end value of the second voltage), and then it is determined whether the four values ​​satisfy the preset relationship. If the four values ​​collected at the start time and the end time of the preset diagnosis time satisfy the preset relationship, it can be determined that the relay to be tested is in a stuck state, thereby improving the accuracy of the relay sticking diagnosis, and timely taking remedial measures when a relay sticking fault is detected; and the double judgment can also improve the robustness of the relay sticking diagnosis, avoid the problem of misjudgment of sticking, and thus improve the circuit reliability.

[0022] In some embodiments, the preset diagnostic time includes N detection times; the relay adhesion diagnosis method also includes: obtaining the initial value of the first voltage and the initial value of the second voltage collected at the start time of the i-th detection time, and the end value of the first voltage and the end value of the second voltage collected at the end time of the i-th detection time; when the initial value of the first voltage, the end value of the first voltage, the initial value of the second voltage and the end value of the second voltage in the i-th detection time do not satisfy the preset relationship, it is determined that the relay to be tested is in a non-adhesion state; when the initial value of the first voltage, the end value of the first voltage, the initial value of the second voltage and the end value of the second voltage in the i-th detection time satisfy the preset relationship, perform an i plus one operation until the initial value of the first voltage, the end value of the first voltage, the initial value of the second voltage and the end value of the second voltage in N detection times all satisfy the preset relationship, and it is determined that the relay to be tested is in a adhesion state; wherein N is a positive integer, and i is an integer greater than or equal to 1 and less than or equal to N.

[0023] Through the above-mentioned technical means, still taking the i-th detection time as an example, the third difference between the end value of the first voltage and the initial value of the first voltage and the fourth difference between the end value of the second voltage and the initial value of the second voltage within the detection time can be first determined, and then determined based on whether the absolute value of the third voltage difference between the third difference and the fourth difference is less than the second voltage threshold; in this way, when the absolute value of the third voltage difference between the third difference and the fourth difference is greater than the second voltage threshold, it indicates that the four values ​​do not satisfy the preset relationship, then it can be determined that the relay to be tested is in a non-sticky state, and the relay sticking diagnosis process can be directly exited at this time; if the absolute value of the third voltage difference between the third difference and the fourth difference within the current detection time is greater than the second voltage threshold, it indicates that the four values ​​satisfy the preset relationship, then the sticking judgment of the next detection time can be performed; thereby, multiple quick inspections can be performed within the preset diagnosis time, adaptive quick detection can be achieved, and whether the relay has a sticking fault can be detected in time; and the double judgment can also improve the robustness of the relay sticking diagnosis, avoid the problem of misjudgment of sticking, and thereby improve the circuit reliability.

[0024] In some embodiments, the relay sticking diagnosis method further includes: when a maximum and minimum voltage relationship between the first voltage and the second voltage within a preset diagnosis time does not satisfy a preset relationship, determining that the relay to be tested is in a non-sticking state.

[0025] Through the above-mentioned technical means, if the maximum and minimum voltage relationship between the first voltage and the second voltage within the preset diagnostic time does not satisfy the preset relationship, it is considered that the change trends on both sides of the relay to be tested are inconsistent, then it can be determined that the relay to be tested is in a non-sticking state, and the relay's sticking diagnosis process is exited, thereby shortening the diagnosis time, and the double judgment can also improve the robustness of the relay sticking diagnosis, avoid the problem of misjudgment of sticking, and thereby improve the circuit reliability.

[0026] In some embodiments, the relay sticking diagnosis method further includes: determining that the relay to be tested is in a non-sticking state when the second voltage is outside a preset voltage range and lasts for a second preset time.

[0027] Through the above-mentioned technical means, the second voltage represents the sampled voltage at both ends of the battery pack and the relay to be tested in series. If the second voltage is not within the preset voltage range and lasts for the second preset time, it can be determined that the relay to be tested is in a non-sticky state. At this time, the relay's sticking diagnosis process can be exited, thereby shortening the diagnosis time and avoiding the problem of misjudgment of sticking.

[0028] In a second aspect, an embodiment of the present application provides a relay adhesion diagnosis device, which is applied to a circuit to be detected, wherein the circuit to be detected includes at least a battery pack and a relay to be detected, and the battery pack and the relay to be detected are connected in series; the relay adhesion diagnosis device includes:

[0029] A first detection branch connected between a first end of the battery pack and a second end of the battery pack, and configured to detect a first voltage across the two ends of the battery pack;

[0030] A second detection branch, wherein the second detection branch is connected between the second end of the battery pack and the second end of the relay to be tested, and is used to detect a second voltage between the two ends of the battery pack and the relay to be tested in series;

[0031] A diagnostic module, configured to obtain a threshold voltage combination corresponding to the first voltage and the second voltage collected within a preset diagnostic time when the absolute value of the voltage difference between the first voltage and the second voltage is less than a first voltage threshold value and lasts for a first preset time; and to determine that the relay to be tested is in a sticking state when the threshold voltage combination corresponding to the first voltage and the second voltage within the preset diagnostic time satisfies a preset relationship;

[0032] Wherein, the threshold voltage combination includes: the maximum value of the first voltage, the minimum value of the first voltage, the maximum value of the second voltage, and the minimum value of the second voltage;

[0033] Alternatively, the threshold voltage combination includes: a maximum voltage difference between the first voltage and the second voltage and a minimum voltage difference between the first voltage and the second voltage;

[0034] Alternatively, the threshold voltage combination includes: an initial value of the first voltage and an initial value of the second voltage collected at the start time of the preset diagnosis time, and an end value of the first voltage and an end value of the second voltage collected at the end time of the preset diagnosis time.

[0035] Through the above-mentioned technical means, the first voltage at both ends of the battery pack is collected through the first detection branch, and the second voltage at both ends of the battery pack and the relay to be tested in series is collected through the second detection branch; then a preliminary judgment is made based on whether the absolute value of the voltage difference between the first voltage and the second voltage is less than the first voltage threshold and lasts for a first preset time, and then a further judgment is made based on whether the threshold voltage combination corresponding to the first voltage and the second voltage collected within the preset diagnosis time satisfies the preset relationship. In this way, if the absolute value of the voltage difference between the first voltage and the second voltage is less than the first voltage threshold and lasts for the first preset time, and the threshold voltage combination corresponding to the first voltage and the second voltage collected within the preset diagnosis time satisfies the preset relationship, then it can be determined that the relay to be tested is in a sticking state, thereby improving the accuracy of the relay sticking diagnosis, and timely taking remedial measures when a relay sticking fault is detected; and the double judgment can also improve the robustness of the relay sticking diagnosis, avoid the problem of misjudgment of sticking, and thereby improve the circuit reliability.

[0036] In some embodiments, the preset diagnostic time includes N detection times; the diagnostic module is also used to obtain a threshold voltage combination corresponding to the first voltage and the second voltage collected within the i-th detection time when the absolute value of the voltage difference between the first voltage and the second voltage is less than the first voltage threshold and lasts for a first preset time; and when the threshold voltage combination corresponding to the first voltage and the second voltage within the i-th detection time does not satisfy a preset relationship, determine that the relay to be tested is in a non-sticky state; wherein N is a positive integer, and i is an integer greater than or equal to 1 and less than or equal to N.

[0037] Through the above-mentioned technical means, taking the i-th detection time as an example, if the threshold voltage combination corresponding to the first voltage and the second voltage collected within the detection time does not satisfy the preset relationship, it is considered that the change trends on both sides of the relay to be tested are inconsistent, and then it is determined that the relay to be tested is in a non-sticking state. At this time, the relay sticking diagnosis process is directly exited, which can not only realize adaptive rapid detection, shorten the diagnosis time, and timely detect whether the relay has a sticking fault, but also avoid the problem of misjudgment of sticking.

[0038] In some embodiments, the diagnostic module is also used to perform an i plus one operation when the threshold voltage combination corresponding to the first voltage and the second voltage within the i-th detection time satisfies a preset relationship, until the threshold voltage combination corresponding to the first voltage and the second voltage within N detection times all satisfies the preset relationship, thereby determining that the relay to be tested is in a sticking state.

[0039] Through the above technical means, still taking the i-th detection time as an example, if the threshold voltage combination corresponding to the first voltage and the second voltage collected in the detection time satisfies the preset relationship, then continue to judge whether the threshold voltage combination corresponding to the first voltage and the second voltage collected in the next detection time satisfies the preset relationship, until the threshold voltage combination corresponding to the first voltage and the second voltage in N detection times all satisfies the preset relationship, then it is determined that the relay to be tested is in a sticking state. Therefore, multiple fast inspections can be performed within the preset diagnosis time, which can not only shorten the diagnosis time and realize adaptive fast detection, but also timely detect whether the relay has a sticking fault, and at the same time avoid the problem of misjudgment of sticking.

[0040] In a third aspect, an embodiment of the present application provides a relay adhesion diagnosis system, which includes a circuit to be detected consisting of a battery pack and a relay to be tested, and a relay adhesion diagnosis device, wherein the battery pack and the relay to be tested are respectively connected to the relay adhesion diagnosis device, and the relay adhesion diagnosis device is used to execute a relay adhesion diagnosis method as described in any one of the first aspects.

[0041] Through the above-mentioned technical means, after the relay adhesion diagnosis device collects the first voltage at both ends of the battery pack and the second voltage at both ends of the battery pack and the relay to be tested in series, if the absolute value of the voltage difference between the first voltage and the second voltage is less than the first voltage threshold and lasts for a first preset time, and the threshold voltage combination corresponding to the first voltage and the second voltage collected within the preset diagnosis time satisfies the preset relationship, indicating that the voltage change trends on both sides of the relay to be tested are basically the same, then it can be determined that the relay to be tested is in a adhesion state, thereby improving the accuracy of the relay adhesion diagnosis, and being able to take remedial measures in time when a relay adhesion fault is detected; and the double judgment can also improve the robustness of the relay adhesion diagnosis, avoid the problem of misjudgment of adhesion, and thereby improve the circuit reliability.

[0042] It should be understood that the above general description and the following detailed description are merely exemplary and explanatory, and are not intended to limit the technical solutions of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 It is a schematic diagram of the architecture of the relay sticking diagnosis circuit;

[0044] Figure 2 It is the schematic diagram of the Y capacitor equivalent circuit of the relay adhesion diagnosis circuit;

[0045] Figure 3 A schematic diagram of the measured data of the sampling voltage corresponding to the main positive relay and the main negative relay;

[0046] Figure 4A schematic diagram of the structure of a circuit to be detected provided in an embodiment of the present application;

[0047] Figure 5 A schematic diagram of a relay adhesion diagnosis method provided in an embodiment of the present application Figure 1 ;

[0048] Figure 6 A schematic diagram of a relay adhesion diagnosis method provided in an embodiment of the present application Figure 2 ;

[0049] Figure 7 A schematic diagram of a relay adhesion diagnosis method provided in an embodiment of the present application Figure 3 ;

[0050] Figure 8 A schematic diagram of a relay adhesion diagnosis method provided in an embodiment of the present application Figure 4 ;

[0051] Fig. 9 A schematic diagram of a relay adhesion diagnosis method provided in an embodiment of the present application Figure 5 ;

[0052] Fig.10 A schematic diagram of a variation trend of a sampling voltage provided in an embodiment of the present application;

[0053] Fig.11 A timing diagram of a relay adhesion diagnosis to be tested provided in an embodiment of the present application;

[0054] Fig.12 A schematic diagram of the structure of a relay adhesion diagnosis device provided in an embodiment of the present application;

[0055] Fig.13 A schematic diagram of the composition structure of a relay adhesion diagnosis system provided in an embodiment of the present application. DETAILED DESCRIPTION

[0056] In order to enable a more detailed understanding of the features and technical contents of the embodiments of the present application, the implementation of the embodiments of the present application is described in detail below in conjunction with the accompanying drawings. The attached drawings are for reference only and are not used to limit the embodiments of the present application.

[0057] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein are only for the purpose of describing the embodiments of this application and are not intended to limit this application.

[0058] In the following description, reference is made to “some embodiments”, which describe a subset of all possible embodiments, but it will 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.

[0059] It should also be pointed out that the terms "first\second\third" involved in the embodiments of the present application are only 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 here can be implemented in an order other than that illustrated or described here.

[0060] In addition, the reference to "embodiment" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiment may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0061] The following is an introduction to the related technologies of this application.

[0062] Battery cells are an important part of batteries. New energy batteries are being used more and more widely in life and industry. For example, new energy vehicles equipped with batteries have been widely used. In addition, batteries are also being increasingly used in the field of energy storage.

[0063] At present, new energy batteries are increasingly used in life and industry. New energy batteries are not only used in energy storage power systems such as hydropower, thermal power, wind power and solar power stations, but are also widely used in electric vehicles such as electric bicycles, electric motorcycles, electric cars, as well as aerospace and other fields. With the continuous expansion of the application field of power batteries, the market demand is also constantly expanding.

[0064] In the embodiments of the present application, the battery may be a battery cell, or may be a battery pack (Pack) composed of multiple battery cells. A battery cell refers to a basic unit that can realize the mutual conversion of chemical energy and electrical energy, and can be used to make a battery module or a battery pack, so as to supply power to an electrical device. A battery cell may be a secondary battery, which refers to a battery cell that can be activated by charging the active material after the battery cell is discharged and can continue to be used. The battery cell may be a lithium-ion battery, a sodium-ion battery, a sodium-lithium-ion battery, a lithium metal battery, a sodium metal battery, a lithium-sulfur battery, a magnesium-ion battery, a nickel-hydrogen battery, a nickel-cadmium battery, a lead-acid battery, etc., which is not limited here.

[0065] In the embodiment of the present application, the battery may also be a single physical module including one or more battery cells to provide higher voltage and capacity. When there are multiple battery cells, the multiple battery cells are connected in series, in parallel or in hybrid connection through a busbar component.

[0066] Furthermore, with the widespread application of batteries in the field of power batteries and energy storage, the country has vigorously promoted the development of new energy vehicles (such as electric cars, power cars, electric motorcycles, etc.). Since the power battery voltage platform used in new energy vehicles is relatively high, if it is not handled properly, it may cause electric shock accidents. Therefore, it is necessary to accurately and reliably detect the relay state on the bus voltage of the power battery to prevent high voltage leakage to the subsequent high voltage connector, thereby posing a risk to personal safety.

[0067] In the related art, Figure 1 Figure 1 is a schematic diagram of the relay adhesion diagnosis circuit. Figure 1 As shown, the relay adhesion diagnostic circuit includes a battery pack 101 and a load module 102. The battery pack 101 may include a battery pack B1, a pre-charging relay K1, a pre-charging resistor R1, a main positive relay K2 and a main negative relay K3. In addition, the battery pack 101 may also include a first positive side equivalent resistor Rp1, a first negative side equivalent resistor Rn1, a first capacitor Y1 and a second capacitor Y2. The load module 102 may be a high-voltage load corresponding to the vehicle, and the load module 102 may include a second resistor R2, a third capacitor Y3, a fourth capacitor Y4, a fifth capacitor X, a second positive side equivalent resistor Rp2 and a second negative side equivalent resistor Rn2. Among them, the first capacitor Y1, the second capacitor Y2, the third capacitor Y3 and the fourth capacitor Y4 are Y capacitors, and the fifth capacitor X is an X capacitor; and the first capacitor Y1 and the second capacitor Y2 are parasitic Y capacitors in the battery pack 101, and the third capacitor Y3 and the fourth capacitor Y4 are physical Y capacitors in the load module 102.

[0068] For example, Figure 1 For example, since the parasitic Y capacitor in the battery pack 101 with a large area of ​​water cooling plate is large, such as the first capacitor Y1 and the second capacitor Y2 are about several hundred nanofarads (Nano Farad, nF); they are connected in series and parallel with the third capacitor Y3 and the fourth capacitor Y4 in the load module 102, so that the equivalent capacitance at both ends of the U2 and U3 sampling branches becomes larger, see Figure 2 shown.

[0069] Here, U1 refers to the sampled voltage across the battery pack B1, U2 refers to the sampled voltage across the main positive relay K2 and the battery pack B1 in series, and U3 refers to the sampled voltage across the main negative relay K3 and the battery pack B1 in series. The first detection branch can be used to collect the sampled voltage U1 across the battery pack B1, and the second detection branch can include a first sampling branch and a second sampling branch. Figure 2As shown, the first sampling branch includes a first switch EN3, a third resistor R3 and a fourth resistor R4, which are used to collect the sampling voltage U3 at both ends of the main negative relay K3 and the battery pack B1 in series, and the second sampling branch includes a second switch EN2, a fifth resistor R5 and a sixth resistor R6, which are used to collect the sampling voltage U2 at both ends of the main positive relay K2 and the battery pack B1 in series. In addition, a first equivalent capacitor C1 is connected in parallel at both ends of the first sampling branch, and a second equivalent capacitor C2 is connected in parallel at both ends of the second sampling branch.

[0070] It should be noted that if the main negative relay K3 performs adhesion diagnosis, the first switch EN3 is closed and the second switch EN2 is opened; if the main positive relay K2 performs adhesion diagnosis, the first switch EN3 is opened and the second switch EN2 is closed. Figure 2 A Y capacitor equivalent circuit is provided in the case of a sticking diagnosis of the main negative relay K3, when the first switch EN3 is closed and the second switch EN2 is open.

[0071] It should also be noted that, considering that the pre-charge resistor R1 and the pre-charge relay K1 are connected in parallel at both ends of the main positive relay K2, when the relay adhesion diagnosis is performed according to the sampled voltage U2, if no relay adhesion occurs, it can be determined that neither the pre-charge relay K1 nor the main positive relay K2 is adhered; if relay adhesion occurs, it is possible that the pre-charge relay K1 is adhered or the main positive relay K2 is adhered. Among them, for the occurrence of relay adhesion, it is not distinguished here whether it is the pre-charge relay K1 or the main positive relay K2 that is adhered. When the embodiment of the present application performs relay adhesion diagnosis according to the sampled voltage U2, only the main positive relay K2 is used as an example for relevant description.

[0072] It should also be noted that Figure 3 This is a schematic diagram of the measured data of the sampling voltage corresponding to the main positive relay and the main negative relay. Figure 3 , the horizontal axis represents time, and the vertical axis represents voltage. 301 represents the sticking diagnosis of the main negative relay K3, which corresponds to the voltage value of U3; 302 represents the sticking diagnosis of the main positive relay K2, which corresponds to the voltage value of U2.

[0073] For example, Figure 3As shown, when the main negative relay K3 is in a closed state, the voltage value of U3 is about 800V; if the main negative relay K3 is disconnected, the voltage value of U3 begins to decrease and drops to 0 after t1 time. When the main positive relay K2 is in a closed state, the voltage value of U2 is about 800V; if the main positive relay K2 is disconnected, the voltage value of U2 begins to decrease and drops to 0 after t2 time. Among them, the size of t1 time and t2 time is related to the parasitic capacitance in the battery pack 101. If the parasitic capacitance is too large, the voltage value of U2 / U3 will decrease slowly.

[0074] It should also be noted that the main positive relay K2 and the main negative relay K3 are disconnected at the same time, but the diagnostic process has a sequence. For example, the diagnostic test of the main negative relay K3 can be performed first, and then the diagnostic test of the main positive relay K2; or the diagnostic test of the main positive relay K2 can be performed first, and then the diagnostic test of the main negative relay K3, without any limitation here.

[0075] That is to say, the adhesion diagnosis circuit in the related art may cause the sampling voltage to drop slowly in some cases, such as Figure 1 The parasitic Y capacitor in the battery pack is large (Y1 and Y2 are several hundred nF), which is connected in series and parallel with the third capacitor Y3 and the fourth capacitor Y4 in the load module, making the equivalent capacitance at both ends of the U2 and U3 sampling branches larger, resulting in a slow drop in the sampling voltage. For example, when the sampling voltage is in the range of 95%~105%×U1 and lasts for 60 milliseconds (millisecond, ms), a relay adhesion fault will be falsely reported. In short, the robustness of adhesion diagnosis in the existing detection circuit is poor, and the phenomenon of false adhesion will occur.

[0076] Based on this, an embodiment of the present application provides a relay adhesion diagnosis method, device and system, which first detects a first voltage at both ends of a battery pack, and detects a second voltage at both ends of a battery pack connected in series with a relay to be tested; then, when the absolute value of the voltage difference between the first voltage and the second voltage is less than a first voltage threshold and lasts for a first preset time, a threshold voltage combination corresponding to the first voltage and the second voltage collected within the preset diagnostic time is obtained; when the threshold voltage combination corresponding to the first voltage and the second voltage within the preset diagnostic time satisfies a preset relationship, it is determined that the relay to be tested is in a adhesion state. In this way, after detecting the first voltage at both ends of the battery pack and the second voltage at both ends of the battery pack and the battery pack connected in series with the relay to be tested, it is judged whether the relay to be tested is stuck according to the size of the first voltage and the second voltage. First, a preliminary judgment is made based on whether the absolute value of the voltage difference between the first voltage and the second voltage is less than the first voltage threshold and lasts for a first preset time. Then, a further judgment is made based on whether the threshold voltage combination corresponding to the first voltage and the second voltage collected within the preset diagnostic time satisfies a preset relationship. In this way, when the two judgment conditions are met at the same time, it can be determined that the relay to be tested is in a sticking state; thereby, the accuracy of the relay sticking diagnosis can be improved, and remedial measures can be taken in time when a relay sticking fault is detected; and the double judgment can also improve the robustness of the relay sticking diagnosis, avoid the problem of misjudgment of sticking, and thereby improve the circuit reliability.

[0077] The various embodiments of the present application will be described in detail below with reference to the accompanying drawings.

[0078] In one embodiment of the present application, Figure 4 The following is a schematic diagram of the structure of a circuit to be detected provided in an embodiment of the present application. Figure 4 As shown, the circuit 40 to be tested may at least include: a battery pack B1 and a relay to be tested, and the battery pack B1 and the relay to be tested are connected in series. Figure 4 One of the pre-charge relay K1, main positive relay K2 and main negative relay K3 shown.

[0079] In the embodiments of the present application, Figure 4 As shown, the circuit to be tested 40 further includes a load module 102, that is, the circuit to be tested 40 may be a circuit formed by the battery pack B1, the relay to be tested and the load module 102 connected in series. The relay to be tested is connected to the first end of the battery pack B1.

[0080] In the embodiment of the present application, the relay to be tested may include a main positive relay K2 and / or a main negative relay K3. Figure 4As shown, when the first end of the battery pack B1 is the positive terminal, the relay to be tested is the main positive relay K2, and the relay to be tested is connected to the positive terminal of the battery pack B1; when the first end of the battery pack B1 is the negative terminal, the relay to be tested is the main negative relay K3, and the relay to be tested is connected to the negative terminal of the battery pack B1. In addition, U1 is the sampling voltage corresponding to the two ends of the battery pack B1, U2 is the sampling voltage corresponding to the two ends of the battery pack B1 and the main positive relay K2 in series, and U3 is the sampling voltage corresponding to the two ends of the battery pack B1 and the main negative relay K3 in series.

[0081] In the embodiments of the present application, Figure 4 As shown, considering the pre-charging function, the circuit 40 to be detected also includes a pre-charging resistor R1 and a pre-charging relay K1, and the pre-charging resistor R1 and the pre-charging relay K1 form a series branch, and the series branch is connected in parallel with the main positive relay K2. In this way, when the relay adhesion diagnosis is performed according to the sampled voltage U2, it can be used to determine whether the pre-charging relay K1 or the main positive relay K2 is adhered. Among them, if relay adhesion occurs, it is possible that the pre-charging relay K1 is adhered or the main positive relay K2 is adhered. Among them, for the occurrence of relay adhesion, it is not distinguished here whether it is the pre-charging relay K1 or the main positive relay K2 that is adhered. When the relay adhesion diagnosis is performed according to the sampled voltage U2, the following only takes the main positive relay K2 as an example for relevant description.

[0082] It can be understood that in the embodiment of the present application, the relay adhesion diagnosis method can be applied to the main positive relay K2 and / or the main negative relay K3. That is to say, the relay adhesion diagnosis method can be applied to the main positive relay K2, or can also be applied to the main negative relay K3, or can even be applied to the various on-off control relays in the high-voltage circuit of the electric vehicle for adhesion diagnosis, without any limitation here.

[0083] In addition, in the embodiment of the present application, when the adhesion diagnosis is performed on the main positive relay K2 and the main negative relay K3, the diagnosis process has a sequence, and the adhesion diagnosis of the main positive relay K2 may be performed first, and then the adhesion diagnosis of the main negative relay K3 may be performed; or the adhesion diagnosis of the main negative relay K3 may be performed first, and then the adhesion diagnosis of the main positive relay K2 may be performed, and no limitation is made here.

[0084] In some embodiments, based on Figure 4 The circuit 40 to be detected is shown, Figure 5 A schematic diagram of a relay adhesion diagnosis method provided in an embodiment of the present application Figure 1 .like Figure 5 As shown, the relay sticking diagnosis method includes:

[0085] S501, detecting a first voltage across the battery pack, and detecting a second voltage across the battery pack connected in series with a relay to be tested.

[0086] It should be noted that in the embodiment of the present application, the circuit to be detected 40 can be a high-voltage circuit, such as the high-voltage circuit of an electric vehicle, the high-voltage circuit where a battery pack is located, etc. Here, the adhesion diagnosis is mainly performed on each on-off control relay in the high-voltage circuit, such as the main positive relay, the main negative relay, etc.

[0087] In addition, in this field, the concepts of high voltage and low voltage are relative. For example, if the voltage of the device to the ground is below the preset threshold value, it can be called low voltage (referred to as "low voltage"); if the voltage of the device to the ground is above the preset threshold value, it can be called high voltage (referred to as "high voltage"). Here, the preset threshold value can be set to 1000V. At this time, high voltage generally refers to bus voltage, battery voltage, etc. above 1000V, but it is not limited to any.

[0088] It should also be noted that, in the embodiment of the present application, the first voltage can be represented by V1, which is obtained by the first detection branch sampling the voltage at both ends of the battery pack; the second voltage can be represented by V2, which is obtained by the second detection branch sampling the voltage at both ends of the battery pack connected in series with the relay to be tested.

[0089] In the embodiment of the present application, the relay to be tested may include a main positive relay K2 and / or a main negative relay K3. Figure 4 For example, the first voltage V1 can be Figure 4 U1 in the figure is the sampling voltage corresponding to both ends of the battery pack B1; when the relay to be tested is the main positive relay K2, the second voltage V2 can be Figure 4 U2 in the figure is the sampling voltage corresponding to the two ends of the battery pack B1 and the main positive relay K2 in series; when the relay to be tested is the main negative relay K3, the second voltage V2 can be Figure 4 U3 in the figure is the sampling voltage corresponding to the two ends of the battery pack B1 and the main negative relay K3 connected in series.

[0090] S502, when the absolute value of the voltage difference between the first voltage and the second voltage is less than a first voltage threshold and lasts for a first preset time, obtaining a threshold voltage combination corresponding to the first voltage and the second voltage collected within a preset diagnosis time.

[0091] In the embodiment of the present application, a preset diagnosis time can be set here. The size of the preset diagnosis time can be obtained by adding a margin time to the minimum sampling time. That is to say, the preset diagnosis time can be represented by T. T is the minimum sampling time required to calculate the voltage drop greater than a certain threshold according to the size of the Y capacitors inside and outside the battery pack, and a certain margin time is reserved on the basis of the minimum sampling time, so as to ensure that the sampling voltage drop within the preset diagnosis time is greater than a certain threshold.

[0092] It should also be noted that the judgment that the absolute value of the voltage difference between the first voltage and the second voltage is less than the first voltage threshold and lasts for the first preset time can be specifically carried out within the preset diagnosis time. That is to say, if within the preset diagnosis time, there is an absolute value of the voltage difference between the first voltage and the second voltage that is less than the first voltage threshold and lasts for the first preset time, then it can be determined that the relay to be tested may be stuck.

[0093] In addition, in the embodiment of the present application, the absolute value of the voltage difference between the first voltage V1 and the second voltage V2 can be represented by |V1 - V2|, and the first voltage threshold can be represented by Vth1. In this way, for the absolute value of the voltage difference between the first voltage and the second voltage being less than the first voltage threshold, it can mean |V1 - V2| < Vth1.

[0094] That is to say, if within the preset diagnosis time, there is |V1 - V2| < Vth1 and it lasts for the first preset time, then it can be determined that the relay to be tested may be stuck. At this time, further adhesion diagnosis is required. At this time, the threshold voltage combination corresponding to the first voltage and the second voltage collected within the preset diagnosis time is obtained.

[0095] Exemplarily, the first voltage threshold can be set to 5% * V1, and the first preset time can be set to 700 ms. Thus, if there is |V1 - V2| < 5% * V1 and it lasts for 700 ms, then it can be determined that the relay to be tested may be stuck. At this time, the threshold voltage combination corresponding to the first voltage and the second voltage collected within the preset diagnosis time is obtained for further adhesion diagnosis.

[0096] In the embodiment of the present application, for the threshold voltage combination, it can include: the maximum value of the first voltage, the minimum value of the first voltage, the maximum value of the second voltage, and the minimum value of the second voltage; or, it can also include: the maximum value of the voltage difference between the first voltage and the second voltage and the minimum value of the voltage difference between the first voltage and the second voltage; or, it can further include: the initial value of the first voltage and the initial value of the second voltage collected at the start time of the preset diagnosis time, and the end value of the first voltage and the end value of the second voltage collected at the end time of the preset diagnosis time

[0097] That is to say, in the embodiment of the present application, the threshold voltage combination here can be distinguished into two dimensions: one dimension is the voltage threshold, for example, obtaining the maximum and minimum values ​​corresponding to the first voltage and the second voltage respectively collected, or it can also be obtaining the maximum and minimum values ​​of the voltage difference between the first voltage and the second voltage collected; the other dimension is the time dimension, for example, within the preset diagnosis time, the voltage values ​​corresponding to the first voltage and the second voltage collected at the first threshold moment (for example, the starting moment of the preset diagnosis time) can be obtained, and the voltage values ​​corresponding to the first voltage and the second voltage collected at the second threshold moment (for example, the end moment of the preset diagnosis time) can be obtained. The following will combine the threshold voltage combination of these two dimensions to explain the adhesion diagnosis of the relay in detail.

[0098] S503: When a threshold voltage combination corresponding to the first voltage and the second voltage within a preset diagnosis time satisfies a preset relationship, it is determined that the relay to be tested is in a sticking state.

[0099] In an embodiment of the present application, the threshold voltage combination within the preset diagnostic time may include the maximum value V1max of the first voltage, the minimum value V1min of the first voltage, the maximum value V2max of the second voltage, and the minimum value V2min of the second voltage; or, the threshold voltage combination may also include the maximum value (V2-V1)max of the voltage difference between the first voltage and the second voltage, and the minimum value (V2-V1)min of the voltage difference between the first voltage and the second voltage; or, the threshold voltage combination may also include the voltage values ​​corresponding to the start and end times of the preset diagnostic time, and no limitation is made here.

[0100] In this way, after obtaining the threshold voltage combination corresponding to the first voltage and the second voltage within the preset diagnostic time, it is determined that the threshold voltage combination corresponding to the first voltage and the second voltage within the preset diagnostic time satisfies the preset relationship. If the threshold voltage combination corresponding to the first voltage and the second voltage within the preset diagnostic time satisfies the preset relationship, it is considered that the change trends on both sides of the relay to be tested are basically the same, and then it can be determined that the relay to be tested is in a sticking state.

[0101] In some embodiments, the relay sticking diagnosis method may further include: determining that the relay to be tested is in a non-sticking state when a maximum-minimum voltage relationship between the first voltage and the second voltage within a preset diagnosis time does not satisfy a preset relationship.

[0102] In an embodiment of the present application, if the maximum and minimum voltage relationship between the first voltage and the second voltage within the preset diagnostic time does not satisfy the preset relationship, it is considered that the change trends on both sides of the relay to be tested are inconsistent, then it can be determined that the relay to be tested is in a non-sticky state, and the relay's sticking diagnosis process is exited, thereby shortening the diagnosis time, and the double judgment can also improve the robustness of the relay sticking diagnosis, avoid the problem of misjudgment of sticking, and thereby improve the circuit reliability.

[0103] It can also be understood that in the embodiment of the present application, the state of the relay may include a sticking state and a non-sticking state. Among them, since the voltage platform of the power battery used in electric vehicles is relatively high, when the relay to be tested needs to be disconnected, if it is not disconnected in time, it may cause an electric shock accident. Here, if it is detected that the relay to be tested is in a non-sticking state, it indicates that the relay to be tested has been disconnected normally; if it is detected that the relay to be tested is in a sticking state, it indicates that the relay to be tested has a sticking failure, and it is necessary to remind the maintenance personnel in time to prevent high voltage leakage to the subsequent high voltage connector and thus bring risks to personal safety.

[0104] An embodiment of the present application provides a relay sticking diagnosis method, after detecting a first voltage V1 at both ends of a battery pack and a second voltage V2 at both ends of the battery pack and a relay to be tested that are connected in series, firstly, whether the relay to be tested is stuck is judged based on the absolute value of the voltage difference between the first voltage V1 and the second voltage V2, and then further judged based on whether a threshold voltage combination corresponding to the first voltage and the second voltage collected within a preset diagnosis time satisfies a preset relationship. In this way, if the absolute value of the voltage difference between the first voltage and the second voltage is less than a first voltage threshold and lasts for a first preset time, and the threshold voltage combination corresponding to the first voltage and the second voltage collected within the preset diagnosis time satisfies the preset relationship, then it can be determined that the relay to be tested is in a sticking state, thereby improving the accuracy of relay sticking diagnosis, and being able to take remedial measures in time when a relay sticking fault is detected; and the double judgment can also improve the robustness of relay sticking diagnosis, avoid the problem of misjudgment of sticking, and thereby improve circuit reliability.

[0105] In another embodiment of the present application, based on the relay sticking diagnosis method in the aforementioned embodiment, considering that the preset diagnosis time is relatively long, in order to shorten the diagnosis time of whether the relay is stuck, adaptive rapid detection can also be used here to improve detection efficiency.

[0106] In the embodiment of the present application, the preset diagnostic time includes N detection times, where N is a positive integer. Each detection time can be regarded as a quick check of the relay to be tested. That is to say, multiple quick checks can be performed within the preset diagnostic time T. For example, each quick check time (i.e., "detection time") can be set to 0.1T.

[0107] In an embodiment of the present application, the preset diagnostic time may be the diagnostic time from moment T0 to moment T1. Among them, moment T0 indicates the moment when the sampling switch of the relay to be tested is closed after the relay to be tested is disconnected, and moment T0 indicates the moment when the sampling switch of the relay to be tested is opened after the relay to be tested is disconnected. It should also be noted that, considering that the sampling branch needs to have a certain response time after the sampling switch of the relay to be tested is closed, the preset diagnostic time may also be the diagnostic time from moment Ta to moment T1. Among them, moment Ta indicates that the response time of the sampling branch is completed, and a valid sampling voltage can be collected at this time.

[0108] For example, assuming that the response time is 20ms, then the interval between time T0 and time Ta is 20ms, and a valid sampling voltage can be obtained after 20ms. In other words, the preset diagnosis time can refer to the diagnosis time between T0 and T1, or more precisely, it can also refer to the diagnosis time between Ta and T1. The size of the response time can be specifically set according to the actual situation of the circuit, and no limitation is made here.

[0109] In some embodiments, the relay adhesion diagnosis method may further include: when the absolute value of the voltage difference between the first voltage and the second voltage is less than the first voltage threshold and lasts for a first preset time, obtaining a threshold voltage combination corresponding to the first voltage and the second voltage collected within the i-th detection time; when the threshold voltage combination corresponding to the first voltage and the second voltage within the i-th detection time does not satisfy a preset relationship, determining that the relay to be tested is in a non-adhesion state; wherein i is an integer greater than or equal to 1 and less than or equal to N.

[0110] That is to say, in an embodiment of the present application, if the threshold voltage combination corresponding to the first voltage and the second voltage collected within a certain detection time does not satisfy the preset relationship, it is considered that the change trends on both sides of the relay to be tested are inconsistent, then it can be determined that the relay to be tested is in a non-sticky state, and at this time the relay sticking diagnosis process is directly exited, thereby not only achieving adaptive rapid detection, shortening the diagnosis time, and timely detecting whether the relay has a sticking fault, but also avoiding the problem of misjudgment of sticking.

[0111] In some embodiments, the relay adhesion diagnosis method may further include: when the threshold voltage combination corresponding to the first voltage and the second voltage within the i-th detection time satisfies a preset relationship, performing an i plus one operation, until the threshold voltage combination corresponding to the first voltage and the second voltage within N detection times all satisfies the preset relationship, determining that the relay to be tested is in a adhesion state.

[0112] That is to say, in the embodiment of the present application, taking the i-th detection time as an example, if the threshold voltage combination corresponding to the first voltage and the second voltage collected within the detection time does not satisfy the preset relationship, it can be determined that the relay to be tested is in a non-adhesion state, and the relay adhesion diagnosis process is directly exited at this time; otherwise, if the threshold voltage combination corresponding to the first voltage and the second voltage collected within the detection time satisfies the preset relationship, then continue to judge whether the threshold voltage combination corresponding to the first voltage and the second voltage collected within the next detection time satisfies the preset relationship, until the threshold voltage combination corresponding to the first voltage and the second voltage within N detection times all satisfies the preset relationship, then it is determined that the relay to be tested is in a adhesion state. Thus, multiple fast inspections can be performed within the preset diagnosis time, which can not only shorten the diagnosis time and realize adaptive fast detection, but also timely detect whether the relay has an adhesion fault, and at the same time, double judgment can also avoid the problem of misjudgment of adhesion.

[0113] In a possible implementation, the threshold voltage combination may include: a maximum value V1max of the first voltage, a minimum value V1min of the first voltage, a maximum value V2max of the second voltage, and a minimum value V2min of the second voltage. Figure 6 A schematic diagram of a relay adhesion diagnosis method provided in an embodiment of the present application Figure 2 .like Figure 6 As shown, after step S501, the relay adhesion diagnosis method may include:

[0114] S601, when the absolute value of the voltage difference between the first voltage and the second voltage is less than the first voltage threshold and lasts for a first preset time, obtain the maximum value of the first voltage, the minimum value of the first voltage, the maximum value of the second voltage, and the minimum value of the second voltage collected within the i-th detection time.

[0115] S602, determining a first difference between a maximum value of the first voltage and a minimum value of the first voltage and a second difference between a maximum value of the second voltage and a minimum value of the second voltage within an i-th detection time.

[0116] In the embodiment of the present application, i is an integer greater than or equal to 1 and less than or equal to N, and N is a positive integer. Taking the i-th detection time as an example, within the detection time, the first difference can be expressed as (V1max-V1min), and the second difference can be expressed as (V2max-V2min).

[0117] S603, determining whether an absolute value of a first voltage difference between the first difference and the second difference within the i-th detection time is less than a second voltage threshold.

[0118] In the embodiment of the present application, for the i-th detection time, the absolute value of the first voltage difference between the first difference and the second difference can be represented by |(V2max-V2min)-(V1max-V1min)|, and the second voltage threshold can be represented by Vth2, so here it can be determined whether |(V2max-V2min)-(V1max-V1min)| is less than Vth2. Exemplarily, the value of Vth2 can be set to 10V, but there is no limitation.

[0119] In some embodiments, after determining a first difference between a maximum value of the first voltage and a minimum value of the first voltage within the i-th detection time and a second difference between a maximum value of the second voltage and a minimum value of the second voltage, the relay adhesion diagnosis method may further include: determining that a threshold voltage combination corresponding to the first voltage and the second voltage within the i-th detection time satisfies a preset relationship when an absolute value of the first voltage difference between the first difference and the second difference is less than a second voltage threshold; and determining that a threshold voltage combination corresponding to the first voltage and the second voltage within the i-th detection time does not satisfy a preset relationship when an absolute value of the first voltage difference between the first difference and the second difference is greater than the second voltage threshold.

[0120] In an embodiment of the present application, if |(V2max-V2min)-(V1max-V1min)| is less than Vth2, then it can be determined that the threshold voltage combination corresponding to the first voltage and the second voltage within the i-th detection time satisfies the preset relationship; if |(V2max-V2min)-(V1max-V1min)| is greater than Vth2, then it can be determined that the threshold voltage combination corresponding to the first voltage and the second voltage within the i-th detection time does not satisfy the preset relationship.

[0121] In addition, in an embodiment of the present application, for the case where |(V2max-V2min)-(V1max-V1min)| is equal to Vth2, if the absolute value of the first voltage difference between the first difference and the second difference is equal to the second voltage threshold, then it can be determined that the threshold voltage combination corresponding to the first voltage and the second voltage within the i-th detection time satisfies the preset relationship, or it can be determined that the threshold voltage combination corresponding to the first voltage and the second voltage within the i-th detection time does not satisfy the preset relationship, and no limitation is made here.

[0122] That is to say, in the embodiment of the present application, still taking the i-th detection time as an example, as to whether the threshold voltage combination corresponding to the first voltage and the second voltage within the detection time satisfies the preset relationship, it can be first determined the first difference between the maximum value of the first voltage and the minimum value of the first voltage and the second difference between the maximum value of the second voltage and the minimum value of the second voltage within the detection time, and then determined based on whether the absolute value of the first voltage difference between the first difference and the second difference is less than the second voltage threshold; in this way, when the absolute value of the first voltage difference between the first difference and the second difference is greater than the second voltage threshold, it indicates that the threshold voltage combination does not satisfy the preset relationship, then it can be determined that the relay to be tested is in a non-sticky state, and at this time the relay sticking diagnosis process can be directly exited, so that multiple quick inspections can be performed within the preset diagnosis time, and adaptive quick detection can be achieved, so as to promptly detect whether the relay has a sticking failure.

[0123] S604, determining that the relay to be tested is in a non-sticky state.

[0124] S605, executing an i plus one operation.

[0125] S606: When the absolute values ​​of the first voltage difference between the first difference and the second difference within N detection times are both smaller than the second voltage threshold, it is determined that the relay to be tested is in a sticking state.

[0126] In the embodiment of the present application, for step S603, if the judgment result is no, that is, |(V2max-V2min)-(V1max-V1min)| in the i-th detection time is greater than the second voltage threshold, then step S604 can be executed, at this time, it is determined that the relay to be tested is in a non-adhesive state, and the relay adhesion diagnosis process can be directly exited; if the judgment result is yes, that is, |(V2max-V2min)-(V1max-V1min)| in the i-th detection time is less than the second voltage threshold, then step S605 can be executed, that is, i plus one operation is performed, and step S603 is returned to be executed to determine whether |(V2max-V2min)-(V1max-V1min)| in the next detection time is less than the second voltage threshold. Until i is equal to N, if |(V2max-V2min)-(V1max-V1min)| is less than the second voltage threshold in N detection times, it is determined that the relay to be tested is in a sticking state.

[0127] Thus, in the embodiment of the present application, if the absolute value of the first voltage difference between the first difference and the second difference within a certain detection time is greater than the second voltage threshold, that is, the threshold voltage combination corresponding to the collected first voltage and the second voltage does not satisfy the preset relationship, it can be determined that the relay to be tested is in a non-adhesion state, and the relay adhesion diagnosis process is directly exited at this time; otherwise, if the absolute value of the first voltage difference between the first difference and the second difference within a certain detection time is less than the second voltage threshold, that is, the threshold voltage combination corresponding to the collected first voltage and the second voltage satisfies the preset relationship, then continue to judge whether the absolute value of the first voltage difference between the first difference and the second difference within the next detection time is less than the second voltage threshold, until the absolute value of the first voltage difference between the first difference and the second difference within N detection times is less than the second voltage threshold, that is, the threshold voltage combination corresponding to the collected first voltage and the second voltage satisfies the preset relationship, then it is determined that the relay to be tested is in a adhesion state. Thus, multiple quick inspections can be performed within the preset diagnosis time, which can not only shorten the diagnosis time and realize adaptive quick detection, but also timely detect whether the relay has an adhesion fault, and at the same time, double judgment can also avoid the problem of misjudgment of adhesion.

[0128] In another possible implementation, the threshold voltage combination may include: a maximum voltage difference between the first voltage and the second voltage (V2-V1)max and a minimum voltage difference between the first voltage and the second voltage (V2-V1)min. Figure 7 A schematic diagram of a relay adhesion diagnosis method provided in an embodiment of the present application Figure 3 .like Figure 7 As shown, after step S501, the relay adhesion diagnosis method may include:

[0129] S701, when the absolute value of the voltage difference between the first voltage and the second voltage is less than the first voltage threshold and lasts for a first preset time, determine the maximum voltage difference between the first voltage and the second voltage and the minimum voltage difference between the first voltage and the second voltage collected within the i-th detection time.

[0130] In the embodiment of the present application, i is an integer greater than or equal to 1 and less than or equal to N, and N is a positive integer. Taking the i-th detection time as an example, within the detection time, the maximum voltage difference can be expressed as (V2-V1)max, and the minimum voltage difference can be expressed as (V2-V1)min.

[0131] S702: Determine whether the absolute value of a second voltage difference between a maximum voltage difference and a minimum voltage difference within an i-th detection time is less than a second voltage threshold.

[0132] In the embodiment of the present application, for the i-th detection time, the absolute value of the second voltage difference between the maximum voltage difference and the minimum voltage difference can be represented by |(V2-V1)max-(V2-V1)min|, and the second voltage threshold can be represented by Vth2, so here it can be determined whether |(V2-V1)max-(V2-V1)min| is less than Vth2. Exemplarily, the value of Vth2 can be set to 10V, but there is no limitation.

[0133] In some embodiments, after determining the maximum voltage difference between the first voltage and the second voltage and the minimum voltage difference between the first voltage and the second voltage collected within the i-th detection time, the relay adhesion diagnosis method may further include: when the absolute value of the second voltage difference between the maximum voltage difference and the minimum voltage difference is less than the second voltage threshold, determining that the threshold voltage combination corresponding to the first voltage and the second voltage within the i-th detection time satisfies a preset relationship; when the absolute value of the second voltage difference between the maximum voltage difference and the minimum voltage difference is greater than the second voltage threshold, determining that the threshold voltage combination corresponding to the first voltage and the second voltage within the i-th detection time does not satisfy the preset relationship.

[0134] In an embodiment of the present application, if |(V2-V1)max-(V2-V1)min| is less than Vth2, then it can be determined that the threshold voltage combination corresponding to the first voltage and the second voltage within the i-th detection time satisfies the preset relationship; if |(V2-V1)max-(V2-V1)min| is greater than Vth2, then it can be determined that the threshold voltage combination corresponding to the first voltage and the second voltage within the i-th detection time does not satisfy the preset relationship.

[0135] In addition, in an embodiment of the present application, for the case where |(V2-V1)max-(V2-V1)min| is equal to Vth2, if the absolute value of the second voltage difference between the maximum voltage difference and the minimum voltage difference is equal to the second voltage threshold, then it can be determined that the threshold voltage combination corresponding to the first voltage and the second voltage within the i-th detection time satisfies the preset relationship, or it can be determined that the threshold voltage combination corresponding to the first voltage and the second voltage within the i-th detection time does not satisfy the preset relationship, and no limitation is made here.

[0136] That is to say, in the embodiment of the present application, still taking the i-th detection time as an example, as to whether the threshold voltage combination corresponding to the first voltage and the second voltage within the detection time satisfies the preset relationship, it can be first determined according to the maximum voltage difference between the first voltage and the second voltage and the minimum voltage difference between the first voltage and the second voltage collected within the detection time, and then determined based on whether the absolute value of the second voltage difference between the maximum voltage difference and the minimum voltage difference is less than the second voltage threshold value; in this way, when the absolute value of the second voltage difference between the maximum voltage difference and the minimum voltage difference is greater than the second voltage threshold value, it indicates that the threshold voltage combination does not satisfy the preset relationship, then it can also be determined that the relay to be tested is in a non-sticky state, and at this time, the relay sticking diagnosis process can be directly exited, so that multiple quick inspections can be performed within the preset diagnosis time, and adaptive quick detection can be achieved, so as to detect in time whether the relay has a sticking failure.

[0137] S703, determining that the relay to be tested is in a non-sticky state.

[0138] S704, executing an i plus one operation.

[0139] S705: When the absolute value of the second voltage difference between the maximum voltage difference and the minimum voltage difference within N detection times is less than the second voltage threshold, it is determined that the relay to be tested is in a sticking state.

[0140] In the embodiment of the present application, for step S702, if the judgment result is no, that is, |(V2-V1)max-(V2-V1)min| is greater than the second voltage threshold value during the i-th detection time, then step S703 can be executed, at which time it is determined that the relay to be tested is in a non-adhesive state, and the relay adhesion diagnosis process can be directly exited; if the judgment result is yes, that is, |(V2-V1)max-(V2-V1)min| is less than the second voltage threshold value during the i-th detection time, then step S704 can be executed, that is, i plus one operation is performed, and step S702 is returned to be executed to determine whether |(V2-V1)max-(V2-V1)min| is less than the second voltage threshold value during the next detection time. Until i is equal to N, if |(V2-V1)max-(V2-V1)min| is less than the second voltage threshold value during N detection times, it is determined that the relay to be tested is in a sticky state.

[0141] Thus, in the embodiment of the present application, if the absolute value of the second voltage difference between the maximum voltage difference and the minimum voltage difference in a certain detection time is greater than the second voltage threshold, that is, the threshold voltage combination corresponding to the collected first voltage and the second voltage does not satisfy the preset relationship, it can be determined that the relay to be tested is in a non-adhesion state, and the relay adhesion diagnosis process is directly exited at this time; otherwise, if the absolute value of the second voltage difference between the maximum voltage difference and the minimum voltage difference in a certain detection time is less than the second voltage threshold, that is, the threshold voltage combination corresponding to the collected first voltage and the second voltage satisfies the preset relationship, then continue to judge whether the absolute value of the second voltage difference between the maximum voltage difference and the minimum voltage difference in the next detection time is less than the second voltage threshold, until the absolute value of the second voltage difference between the maximum voltage difference and the minimum voltage difference in N detection times is less than the second voltage threshold, that is, the threshold voltage combination corresponding to the collected first voltage and the second voltage satisfies the preset relationship, then it is determined that the relay to be tested is in a adhesion state. Thus, multiple quick inspections can be performed within the preset diagnosis time, which can not only shorten the diagnosis time and realize adaptive quick detection, but also detect whether the relay has adhesion failure in time, and at the same time, double judgment can also avoid the problem of misjudgment of adhesion.

[0142] In another possible implementation, the threshold voltage combination may include voltage values ​​corresponding to the start time and the end time of the preset diagnosis time. Exemplarily, the threshold voltage combination may include: an initial value of the first voltage and an initial value of the second voltage collected at the start time of the preset diagnosis time, and an end value of the first voltage and an end value of the second voltage collected at the end time of the preset diagnosis time.

[0143] Figure 8 A schematic diagram of a relay adhesion diagnosis method provided in an embodiment of the present application Figure 4 .like Figure 8 As shown, after step S501, the relay adhesion diagnosis method may include:

[0144] S801, when the absolute value of the voltage difference between the first voltage and the second voltage is less than the first voltage threshold and lasts for a first preset time, obtain the initial value of the first voltage and the initial value of the second voltage collected at the start time of the preset diagnostic time, and the end value of the first voltage and the end value of the second voltage collected at the end time of the preset diagnostic time.

[0145] It should be noted that at the initial moment of the preset diagnostic time, the initial value of the first voltage collected can be represented by V1init, and the initial value of the second voltage collected can be represented by V2init; at the end moment of the preset diagnostic time, the end value of the first voltage collected can be represented by V1final, and the end value of the second voltage collected can be represented by V2final.

[0146] In some embodiments, determining whether a preset relationship is satisfied among an initial value of a first voltage, an end value of the first voltage, an initial value of a second voltage, and an end value of the second voltage within a preset diagnostic time may include: determining a third difference between the end value of the first voltage and the initial value of the first voltage within the preset diagnostic time and a fourth difference between the end value of the second voltage and the initial value of the second voltage; and determining whether an absolute value of a third voltage difference between the third difference and the fourth difference within the preset diagnostic time is less than a second voltage threshold.

[0147] It should also be noted that, in the embodiment of the present application, the third difference can be represented by (V1final-V1init), the fourth difference can be represented by (V2final-V2init), the absolute value of the third voltage difference between the third difference and the fourth difference can be represented by |(V2final-V2init)-(V1final-V1init)|, and the second voltage threshold can be represented by Vth2. Exemplarily, the value of Vth2 can be set to 10V, but no limitation is made.

[0148] That is to say, in the embodiment of the present application, it can be determined whether |(V2final-V2init)-(V1final-V1init)| is less than the second voltage threshold, so as to determine whether the initial value V1init of the first voltage, the final value V1final of the first voltage, the initial value V2init of the second voltage and the final value V2final of the second voltage within the preset diagnosis time satisfy the preset relationship. If |(V2final-V2init)- (V1final-V1init)| is equal to the second voltage threshold, then it can be considered that it satisfies the preset relationship, or it can be considered that it does not satisfy the preset relationship, which is not specifically limited here.

[0149] S802, when a preset relationship is satisfied among an initial value of the first voltage, an end value of the first voltage, an initial value of the second voltage, and an end value of the second voltage within a preset diagnosis time, determining that the relay to be tested is in a sticking state.

[0150] S803, when the initial value of the first voltage, the end value of the first voltage, the initial value of the second voltage and the end value of the second voltage within the preset diagnosis time do not satisfy a preset relationship, determine that the relay to be tested is in a non-sticking state.

[0151] It should also be noted that when |V1-V2| is less than the first voltage threshold and lasts for the first preset time, if |(V2final-V2init)-(V1final-V1init)| within the preset diagnostic time is less than the second voltage threshold, that is, the initial value of the first voltage, the end value of the first voltage, the initial value of the second voltage and the end value of the second voltage within the preset diagnostic time satisfy the preset relationship, then it can be determined that the relay to be tested is in a sticking state; otherwise, if |(V2final-V2init)-(V1final-V1init)| within the preset diagnostic time is greater than the second voltage threshold, that is, the initial value of the first voltage, the end value of the first voltage, the initial value of the second voltage and the end value of the second voltage within the preset diagnostic time do not satisfy the preset relationship, then it can be considered that the change trends on both sides of the relay to be tested are inconsistent, then it can be determined that the relay to be tested is in a non-sticking state.

[0152] Thus, in an embodiment of the present application, when it is detected that the absolute value of the voltage difference between the first voltage and the second voltage is less than the first voltage threshold and lasts for a first preset time, it is determined that the relay to be tested may be stuck; then the first voltage and the second voltage corresponding to the start time and the end time of the preset diagnosis time are obtained (i.e., the four values ​​of the initial value of the first voltage, the end value of the first voltage, the initial value of the second voltage, and the end value of the second voltage), and then it is determined whether the four values ​​satisfy the preset relationship. If the four values ​​collected at the start time and the end time of the preset diagnosis time satisfy the preset relationship, it can be determined that the relay to be tested is in a stuck state, thereby improving the accuracy of the relay sticking diagnosis, and timely taking remedial measures when a relay sticking fault is detected; and the double judgment can also improve the robustness of the relay sticking diagnosis, avoid the problem of misjudgment of sticking, and thereby improve the circuit reliability.

[0153] In another possible implementation, the preset diagnosis time may include N detection times, and the threshold voltage combination may include: voltage values ​​corresponding to the start time and the end time of the i-th detection time. Exemplarily, the threshold voltage combination may include: an initial value of the first voltage and an initial value of the second voltage collected at the start time of the i-th detection time, and an end value of the first voltage and an end value of the second voltage collected at the end time of the i-th detection time.

[0154] Fig. 9 A schematic diagram of a relay adhesion diagnosis method provided in an embodiment of the present application Figure 5 .like Fig. 9 As shown, after step S501, the relay adhesion diagnosis method may include:

[0155] S901, acquiring an initial value of a first voltage and an initial value of a second voltage collected at a start time of an i-th detection time, and an end value of the first voltage and an end value of the second voltage collected at an end time of an i-th detection time.

[0156] S902 , determining a third difference between an end value of the first voltage and an initial value of the first voltage and a fourth difference between an end value of the second voltage and an initial value of the second voltage within an i-th detection time.

[0157] In the embodiment of the present application, i is an integer greater than or equal to 1 and less than or equal to N, and N is a positive integer. Taking the i-th detection time as an example, according to the collected initial value V1init of the first voltage, the initial value V2init of the second voltage, the final value V1final of the first voltage, and the final value V2final of the second voltage, the third difference can be obtained as (V1final-V1init) and the fourth difference can be obtained as (V2final-V2init).

[0158] S903, determining whether an absolute value of a third voltage difference between the third difference and the fourth difference corresponding to the i-th detection time is less than a second voltage threshold.

[0159] In the embodiment of the present application, for the i-th detection time, the absolute value of the third voltage difference between the third difference and the fourth difference can be represented by |(V2final-V2init)-(V1final-V1init)|, and the second voltage threshold can be represented by Vth2, so here it can be determined whether |(V2final-V2init)-(V1final-V1init)| is less than Vth2. Exemplarily, the value of Vth2 can be set to 10V, but there is no limitation.

[0160] In some embodiments, after determining the third difference between the end value of the first voltage and the initial value of the first voltage within the i-th detection time and the fourth difference between the end value of the second voltage and the initial value of the second voltage, the relay adhesion diagnosis method may further include: when the absolute value of the third voltage difference between the third difference and the fourth difference is less than the second voltage threshold, determining that the initial value of the first voltage, the end value of the first voltage, the initial value of the second voltage, and the end value of the second voltage within the i-th detection time satisfy a preset relationship; when the absolute value of the third voltage difference between the third difference and the fourth difference is greater than the second voltage threshold, determining that the initial value of the first voltage, the end value of the first voltage, the initial value of the second voltage, and the end value of the second voltage within the i-th detection time do not satisfy the preset relationship.

[0161] In an embodiment of the present application, if |(V2final-V2init)-(V1final-V1init)| is less than Vth2, it can be determined that the initial value of the first voltage, the end value of the first voltage, the initial value of the second voltage, and the end value of the second voltage within the i-th detection time satisfy a preset relationship; if |(V2final- V2init)-(V1final-V1init)| is greater than Vth2, it can be determined that the initial value of the first voltage, the end value of the first voltage, the initial value of the second voltage, and the end value of the second voltage within the i-th detection time do not satisfy the preset relationship.

[0162] In addition, in the embodiment of the present application, for the case where |(V2final-V2init)-(V1final-V1init)| is equal to Vth2, if the absolute value of the third voltage difference between the third difference and the fourth difference is equal to the second voltage threshold, then it can be determined that the four values ​​satisfy the preset relationship, or it can be determined that the four values ​​do not satisfy the preset relationship, and no limitation is made here.

[0163] S904, determining that the relay to be tested is in a non-sticky state.

[0164] S905, executing an i plus one operation.

[0165] S906: When the absolute value of the third voltage difference between the third difference and the fourth difference within N detection times is less than the second voltage threshold, it is determined that the relay to be tested is in a sticking state.

[0166] In the embodiment of the present application, for step S903, if the judgment result is no, that is, the |(V2final-V2init)-(V1final-V1init)| corresponding to the i-th detection time is greater than the second voltage threshold, then step S904 can be executed, and it is determined that the relay to be tested is in a non-adhesive state at this time, and the relay adhesion diagnosis process can be directly exited; if the judgment result is yes, that is, the |(V2max-V2min)- (V1max-V1min)| corresponding to the i-th detection time is less than the second voltage threshold, then step S905 can be executed, that is, i plus one operation is performed, until the initial value of the first voltage, the end value of the first voltage, the initial value of the second voltage, and the end value of the second voltage within N detection times all meet the preset relationship, it is determined that the relay to be tested is in a sticking state. In other words, i is added by one, and step S903 is returned to be executed to determine whether the |(V2final-V2init)-(V1final-V1init)| corresponding to the next detection time is less than the second voltage threshold. Until i is equal to N, if |(V2final-V2init)-(V1final-V1init)| is less than the second voltage threshold value within N detection times, it can be determined that the relay to be tested is in a sticking state.

[0167] That is to say, in an embodiment of the present application, if |(V2final-V2init)-(V1final-V1init)| corresponding to the i-th detection time is greater than the second voltage threshold, that is, the initial value of the first voltage, the end value of the first voltage, the initial value of the second voltage and the end value of the second voltage within the i-th detection time do not satisfy the preset relationship, then it can be determined that the relay to be tested is in a non-sticky state; if |(V2final-V2init)- (V1final-V1init)| corresponding to the i-th detection time is less than the second voltage threshold, then the adhesion judgment of the next detection time can be performed, until |(V2final-V2init)-(V1final-V1init)| within N detection times is less than the second voltage threshold, that is, the initial value of the first voltage, the end value of the first voltage, the initial value of the second voltage and the end value of the second voltage within N detection times all satisfy the preset relationship, then it can be determined that the relay to be tested is in a sticky state.

[0168] Thus, in the embodiment of the present application, still taking the i-th detection time as an example, to determine whether the four values ​​satisfy the preset relationship, the third difference between the end value of the first voltage and the initial value of the first voltage and the fourth difference between the end value of the second voltage and the initial value of the second voltage within the detection time can be first determined, and then determined based on whether the absolute value of the third voltage difference between the third difference and the fourth difference is less than the second voltage threshold; in this way, when the absolute value of the third voltage difference between the third difference and the fourth difference is greater than the second voltage threshold, it indicates that the four values ​​do not satisfy the preset relationship, then it can be determined that the relay to be tested is in a non-adhesion state, and the relay adhesion diagnosis process can be directly exited at this time; if the absolute value of the third voltage difference between the third difference and the fourth difference within the current detection time is greater than the second voltage threshold, it indicates that the four values ​​satisfy the preset relationship, then the adhesion judgment of the next detection time can be performed; thereby, multiple quick inspections can be performed within the preset diagnosis time, adaptive quick detection can be achieved, and whether the relay has a adhesion fault can be detected in time; and the double judgment can also improve the robustness of the relay adhesion diagnosis, avoid the problem of misjudgment of adhesion, and thereby improve the circuit reliability.

[0169] In yet another possible implementation, the relay sticking diagnosis method may further include: determining that the relay to be tested is in a non-sticking state when the second voltage is outside a preset voltage range and lasts for a second preset time.

[0170] In the embodiment of the present application, the second voltage V2 represents the sampled voltage at both ends of the battery pack and the relay to be tested in series. The preset voltage range can be represented by [(100-x)%*V1, (100+x)%*V1]. If the collected second voltage V2 is not within the interval of (100±x)%*V1 and lasts for the second preset time, it is considered that the relay is in a non-adhesive state.

[0171] In addition, in the embodiment of the present application, x is a preset value, and the value of x can be set according to the sampling accuracy. For example, the value of x can be 5, then the preset voltage range can be [95%*V1, 105%*V1], which is not specifically limited here.

[0172] For example, Figure 1 For example, when the relay to be tested is disconnected, the variation trend of the sampled voltage is always a downward trend. Among them, the smaller the Y capacitor in the battery pack 101, the greater the degree of voltage mutation. Fig.10 A schematic diagram of a variation trend of a sampling voltage provided in an embodiment of the present application. Fig.10As shown, the horizontal axis represents time, and the vertical axis represents the voltage magnitude of the second voltage V2. 1001 represents the sampling voltage curve when the Y capacitor in the battery pack is small, 1002 represents the sampling voltage curve when the Y capacitor in the battery pack is large, and 1003 represents the sampling voltage curve when the relay to be tested is stuck.

[0173] exist Fig.10 In the case of a large Y capacitor in the battery pack, the voltage drops slowly. At this time, when the second sampling voltage V2 is at [95%*V1, 105%*V1] and lasts for 60ms, it is easy to falsely report that the relay is sticking. Here, when the relay to be tested is sticking, the on-resistance is in the milliohm level, and the sampling resistance is in the megohm level. Therefore, as long as the potentials on both sides of the relay contacts to be tested are equal, the sampling voltage remains constant. Fig.10 As shown in 1003. Therefore, the embodiment of the present application can judge based on whether the second voltage V2 is outside [95%*V1, 105%*V1] and lasts for the second preset time.

[0174] That is to say, in an embodiment of the present application, for the collected second voltage, if the second voltage is not within the preset voltage range and lasts for the second preset time, then it can be determined that the relay to be tested is in a non-sticky state. At this time, the relay sticking diagnosis process can be exited, thereby shortening the diagnosis time and avoiding the problem of misjudgment of sticking.

[0175] In an embodiment of the present application, a relay adhesion diagnosis method is provided, in which a preset diagnosis time includes multiple detection times, so that multiple quick inspections can be performed within the preset diagnosis time, which can not only shorten the diagnosis time and realize adaptive quick detection, but also timely detect whether the relay has a adhesion fault. At the same time, double judgment can also avoid the problem of misjudgment of adhesion, thereby improving circuit reliability.

[0176] In another embodiment of the present application, based on the relay adhesion diagnosis method in the foregoing embodiment, an adaptive detection solution is provided, which may include:

[0177] (1) If the sample voltage V2 for diagnosis is not in the range of (100±5)%*V1 and lasts for time t, it can be considered that the relay is not sticking.

[0178] (2) Adaptive fast detection: Set a maximum preset diagnostic time T (T can be calculated based on the size of the Y capacitor inside and outside the battery pack to calculate the minimum sampling time required for the voltage drop to be greater than a certain voltage threshold Vth, and reserve a certain margin time on the basis of the minimum sampling time to ensure that the sampling voltage drop within the T time is greater than Vth). Based on the preset diagnostic time, calculate whether the difference between the maximum and minimum amplitudes of the sampled voltages on both sides of the relay to be tested is consistent. If the difference is greater than ±Vth, it can be considered that the change trends on both sides of the relay to be tested are inconsistent, that is, the relay to be tested is in a non-sticking state, and then exit the relay sticking diagnosis process. Otherwise, it is considered that the relay to be tested is in a sticking state.

[0179] by Figure 1 For example, for Figure 1 The voltage waveform characteristics of the sampling voltage U2 / U3 in the battery pack are as follows: the smaller the Y capacitor in the battery pack, the greater the voltage mutation, and the voltage change trend is downward; when the relay is stuck, the on-resistance is in the milliohm level, and the sampling resistance is in the megohm level, so as long as the potential on both sides of the relay contact is equal, the sampling voltage remains constant. Fig.10 .

[0180] Combine the following Figure 1 The relay adhesion diagnosis method provided in the embodiment of the present application is described. Here, in the case of relay adhesion, it is not distinguished whether the pre-charging relay K1 or the main positive relay K2 is adhered. When the embodiment of the present application performs relay adhesion diagnosis according to the sampled voltage U2, only the main positive relay K2 is used as an example for relevant description. In addition, the main positive relay K2 and the main negative relay K3 are disconnected at the same time, but the diagnostic process has a sequence. For example, the diagnostic test of the main positive relay K2 can be performed first, and then the diagnostic test of the main negative relay K3 can be performed.

[0181] In the embodiments of the present application, Fig.11 A timing diagram of a relay adhesion diagnosis to be tested provided in an embodiment of the present application. Fig.11As shown, the preset diagnostic time corresponding to the main positive relay K2 can be the diagnostic time from time T0 to time T1. Among them, after the main positive relay K2 and the main negative relay K3 are disconnected, time T0 represents the moment of closing the sampling switch of the main positive relay K2, and time T1 represents the moment of opening the sampling switch of the main positive relay K2 and closing the sampling switch of the main negative relay K3. It should also be noted that, considering that the sampling branch needs to have a certain response time t11 after the sampling switch of the main positive relay K2 is closed, the preset diagnostic time can also be the diagnostic time from time Ta to time T1. Among them, time Ta indicates that the response time t11 of the first sampling branch is completed, and the valid sampling voltage can be collected at this time. In addition, the preset diagnostic time corresponding to the main positive relay K2 can include N detection times, where N is a positive integer. Among them, each detection time can be regarded as a quick check on the relay to be tested. That is to say, multiple quick checks can be performed within the preset diagnostic time T. For example, each quick check time (ie, "detection time") can be set to 0.1T, such as Fig.11 As shown, a quick check time may be the diagnosis time t12 between time T0.1 and time T0.2.

[0182] It should be noted that, continue to refer to Fig.11 , the preset diagnostic time corresponding to the main negative relay K3 can be the diagnostic time from moment T1 to moment T2. At this time, moment T1 represents the moment when the sampling switch of the main positive relay K2 is disconnected and the sampling switch of the main negative relay K3 is closed. Among them, moment Tb represents the completion of the response time t21 of the second sampling branch, at which time a valid sampling voltage can be collected, then the preset diagnostic time can also be the diagnostic time from moment Tb to moment T2, and the preset diagnostic time corresponding to the main negative relay K3 can include N detection times. Among them, each detection time can be regarded as a quick check of the relay to be tested. Exemplarily, each quick check time (ie "detection time") can be set to 0.1T, such as Fig.11 As shown, a quick check time may be the diagnosis time t22 between time T1.1 and time T1.2.

[0183] It should also be noted that, whether it is the sampling switch of the main positive relay K2 or the sampling switch of the main negative relay K3, the sampling switch can be a metal-oxide-semiconductor field-effect transistor (Metal-Oxide-SemiconductorField-Effect Transistor, MOSFET or MOS tube for short), a switch tube, a triode, a transistor, a relay switch, etc., without any limitation here.

[0184] It should also be noted that the preset diagnosis time and detection time corresponding to the adhesion diagnosis of the main positive relay K2 and the main negative relay K3 can be the same or different, depending on the actual situation. For example, the preset diagnosis time and detection time corresponding to the adhesion diagnosis of the main positive relay K2 and the main negative relay K3 are set to be the same for exemplary description. The preset diagnosis time can be 1000ms, each fast detection time can be 150ms, and the response time of each sampling branch can be 20ms.

[0185] In the embodiment of the present application, the diagnosis process of the main positive relay K2 is the same as that of the main negative relay K3. Here, the diagnosis process of the main positive relay K2 is used for explanation.

[0186] Judgment condition 1: during the period from T0 to T1, when |U1-U2|<5%*U1 exists and lasts for the first preset time, it is determined that the main positive relay K2 is in a sticking state, that is, the main positive relay K2 has a sticking fault.

[0187] In the embodiment of the present application, the first preset time may be 700 ms, but is not limited thereto.

[0188] Here, if |U1-U2|<5%*U1 does not exist during the period from T0 to T1 and lasts for the first preset time, it is determined that the main positive relay K2 is in a non-sticky state, that is, the main positive relay K2 is normal, and the sticking diagnosis of the main positive relay K2 is terminated in advance.

[0189] Judgment condition 2 (adaptive fast detection): During T0-T1 (T0.1-T0.2), if any of the following conditions is met, it will jump directly to T1, thus ending the adhesion diagnosis of the main positive relay K2.

[0190] Judgment condition 2.1: If |U1-U2|<5%*U1 exists and lasts for the second preset time, it is determined that the main positive relay K2 is in a sticking state.

[0191] Here, the second preset time may be 150 milliseconds, but there is no limitation here.

[0192] Judgment condition 2.2: 20ms after closing the sampling switch of the main positive relay K2, during the period from Ta to T1, if |(U2max-U2min)-(U1max-U1min)|<10V, it is judged that the main positive relay K2 has no abnormality.

[0193] Here, the maximum and minimum values ​​corresponding to U2 need to be greater than 50% of the battery voltage. At this time, the voltage data collected by the main positive relay K2 needs to be confirmed to be normal.

[0194] That is to say, in the embodiment of the present application, the diagnostic strategy of the present technical solution is: voltage drop + adaptive detection. The determination strategy here needs to satisfy determination condition 1 and determination condition 2 at the same time, and then the relay is considered to be in a sticking state.

[0195] Here, if the diagnostic sampling voltage is not in the range of (100±x)%*V1 for a period of t, then it can be considered that the relay is not sticking; wherein the x parameter is set according to the sampling accuracy.

[0196] In addition, in an embodiment of the present application, adaptive fast detection: a longest diagnostic time T is set (T can be calculated based on the size of the Y capacitor inside and outside the package. The minimum sampling time required for the drop to be greater than a certain threshold Vth is obtained by reserving a certain margin time on the basis of the minimum sampling time to ensure that the sampling voltage drop within the T time>Vth), there are multiple fast inspections within the preset diagnostic time T, and each fast inspection time can be set to 0.1T. By calculating whether the difference between the maximum and minimum amplitudes of the sampled voltage on both sides of the relay to be tested is consistent, if the difference is greater than ±Vth, it is considered that the voltage change trends on both sides of the relay are inconsistent, that is, the relay is not sticking. At this time, if the non-sticking condition is met, the relay sticking diagnosis process can be exited immediately, otherwise the relay is considered to be stuck.

[0197] It can be understood that in the embodiment of the present application, if both judgment condition 1 and judgment condition 2 are satisfied, the relay is considered to be stuck. Among them, for judgment condition 2.2, the judgment condition of sticking in each fast detection time from Ta to T1 |(U2max-U2min)-(U1max-U1min)|<10V can be expanded to:

[0198] (1) |(U2-U2init)- (U1-U1init)|<10V, U2 and U1 are the end voltages of the diagnosis completion time from Ta to T1 or the voltages at the end of each quick test, and U3init and U1init are the initial voltages at Ta. Calculate whether the difference in amplitude between the end and start time of the sampling voltages on both sides of the relay is consistent within the preset diagnosis time. If the difference is greater than ±Vth, it is considered that the change trends on both sides of the relay are inconsistent, and the relay is not stuck at this time, and then exit the relay sticking diagnosis process, otherwise it is considered that the relay is stuck.

[0199] (2) |(U2-U1)max-(U2-U1)min|<10V, (U2-U1)max is the maximum value calculated by real-time sampling during each fast detection time, and (U2-U1)min is the minimum value calculated by real-time sampling during each fast detection time. The difference in the amplitude of the sampled voltages on both sides of the relay is calculated in real time within the preset diagnostic time to see if it is consistent. If the difference is greater than ±Vth, it is considered that the change trends on both sides of the relay are inconsistent. At this time, the relay is not stuck, and then the relay sticking diagnosis process is exited. Otherwise, the relay is considered to be stuck.

[0200] The embodiment of the present application provides a relay adhesion diagnosis method, and the specific implementation of the aforementioned embodiment is elaborated in detail through the above embodiment. It can be seen that according to the technical scheme of the aforementioned embodiment, a preliminary judgment is first made based on whether the absolute value of the voltage difference between the first voltage and the second voltage is less than the first voltage threshold and lasts for a first preset time, and then a further judgment is made based on whether the threshold voltage combination corresponding to the first voltage and the second voltage collected within the preset diagnosis time satisfies a preset relationship. In this way, when the two judgment conditions are met at the same time, it can be determined that the relay to be tested is in a adhesion state; thereby, the accuracy of relay adhesion diagnosis can be improved, and adaptive rapid detection can be achieved, shortening the adhesion diagnosis time, so that remedial measures can be taken in time when a relay adhesion failure occurs; in addition, the double judgment here can also improve the robustness of relay adhesion diagnosis, avoid the problem of misjudgment of adhesion, and thereby improve circuit reliability.

[0201] In another embodiment of the present application, based on the relay adhesion diagnosis method in the foregoing embodiment, Fig.12 The schematic diagram of the structure of a relay adhesion diagnosis device provided in an embodiment of the present application. The relay adhesion diagnosis device is applied to a circuit 40 to be detected, and the circuit 40 to be detected at least includes a battery pack and a relay to be detected, and the battery pack and the relay to be detected are connected in series. Fig.12 As shown, the relay sticking diagnostic device 120 may include:

[0202] A first detection branch 1201, wherein the first detection branch is connected between a first end of the battery pack and a second end of the battery pack, and is used to detect a first voltage across the two ends of the battery pack;

[0203] A second detection branch 1202, wherein the second detection branch is connected between the second end of the battery pack and the second end of the relay to be tested, and is used to detect a second voltage between the two ends of the battery pack and the relay to be tested in series;

[0204] The diagnostic module 1203 is used to obtain a threshold voltage combination corresponding to the first voltage and the second voltage collected within a preset diagnostic time when the absolute value of the voltage difference between the first voltage and the second voltage is less than a first voltage threshold and lasts for a first preset time; and to determine that the relay to be tested is in a sticking state when the threshold voltage combination corresponding to the first voltage and the second voltage within the preset diagnostic time satisfies a preset relationship.

[0205] Wherein, the threshold voltage combination may include: the maximum value of the first voltage, the minimum value of the first voltage, the maximum value of the second voltage, and the minimum value of the second voltage. Alternatively, the threshold voltage combination may include: the maximum value of the voltage difference between the first voltage and the second voltage, and the minimum value of the voltage difference between the first voltage and the second voltage. Alternatively, the threshold voltage combination may include: the initial value of the first voltage and the initial value of the second voltage collected at the start time of the preset diagnosis time, and the end value of the first voltage and the end value of the second voltage collected at the end time of the preset diagnosis time.

[0206] In an embodiment of the present application, a first voltage across the battery pack is collected through a first detection branch 1201, and a second voltage across the battery pack and a relay to be tested in series is collected through a second detection branch 1202; then in the diagnostic module 1203, a preliminary judgment is first made based on whether the absolute value of the voltage difference between the first voltage and the second voltage is less than a first voltage threshold and lasts for a first preset time, and then a further judgment is made based on whether a threshold voltage combination corresponding to the first voltage and the second voltage collected within the preset diagnostic time satisfies a preset relationship. In this way, if the absolute value of the voltage difference between the first voltage and the second voltage is less than the first voltage threshold and lasts for a first preset time, and the threshold voltage combination corresponding to the first voltage and the second voltage collected within the preset diagnostic time satisfies the preset relationship, then it can be determined that the relay to be tested is in a sticking state, thereby improving the accuracy of the relay sticking diagnosis, and timely taking remedial measures when a relay sticking fault is detected; and the double judgment can also improve the robustness of the relay sticking diagnosis, avoid the problem of misjudgment of sticking, and thereby improve the circuit reliability.

[0207] In some embodiments, the preset diagnostic time includes N detection times; the diagnostic module 1203 is also used to obtain a threshold voltage combination corresponding to the first voltage and the second voltage collected within the i-th detection time when the absolute value of the voltage difference between the first voltage and the second voltage is less than the first voltage threshold and lasts for a first preset time; and when the threshold voltage combination corresponding to the first voltage and the second voltage within the i-th detection time does not satisfy a preset relationship, determine that the relay to be tested is in a non-sticking state; wherein N is a positive integer, and i is an integer greater than or equal to 1 and less than or equal to N.

[0208] In an embodiment of the present application, taking the i-th detection time as an example, if the threshold voltage combination corresponding to the first voltage and the second voltage collected within the detection time does not satisfy the preset relationship, it is considered that the change trends on both sides of the relay to be tested are inconsistent, then it is determined that the relay to be tested is in a non-sticky state, and the relay sticking diagnosis process is directly exited at this time, thereby not only realizing adaptive rapid detection, shortening the diagnosis time, and timely detecting whether the relay has a sticking fault, but also avoiding the problem of misjudgment of sticking.

[0209] In some embodiments, the diagnostic module 1203 is also used to perform an i plus one operation when the threshold voltage combination corresponding to the first voltage and the second voltage within the i-th detection time satisfies a preset relationship, until the threshold voltage combination corresponding to the first voltage and the second voltage within N detection times all satisfies the preset relationship, thereby determining that the relay to be tested is in a sticking state.

[0210] In the embodiment of the present application, still taking the i-th detection time as an example, if the threshold voltage combination corresponding to the first voltage and the second voltage collected in the detection time satisfies the preset relationship, then continue to judge whether the threshold voltage combination corresponding to the first voltage and the second voltage collected in the next detection time satisfies the preset relationship, until the threshold voltage combination corresponding to the first voltage and the second voltage in N detection times all satisfies the preset relationship, then it is determined that the relay to be tested is in a sticking state. Thus, multiple fast inspections can be performed within the preset diagnosis time, which can not only shorten the diagnosis time and realize adaptive fast detection, but also timely detect whether the relay has a sticking fault, and at the same time avoid the problem of misjudgment of sticking.

[0211] In some embodiments, the threshold voltage combination includes: the maximum value of the first voltage, the minimum value of the first voltage, the maximum value of the second voltage, and the minimum value of the second voltage; accordingly, the diagnostic module 1203 is also used to determine a first difference between the maximum value of the first voltage and the minimum value of the first voltage within the i-th detection time and a second difference between the maximum value of the second voltage and the minimum value of the second voltage; when the absolute value of the first voltage difference between the first difference and the second difference is less than the second voltage threshold, it is determined that the threshold voltage combination corresponding to the first voltage and the second voltage within the i-th detection time satisfies the preset relationship; when the absolute value of the first voltage difference between the first difference and the second difference is greater than the second voltage threshold, it is determined that the threshold voltage combination corresponding to the first voltage and the second voltage within the i-th detection time does not satisfy the preset relationship.

[0212] In some embodiments, the threshold voltage combination includes: a maximum voltage difference between the first voltage and the second voltage and a minimum voltage difference between the first voltage and the second voltage; accordingly, the diagnostic module 1203 is also used to determine the maximum voltage difference between the first voltage and the second voltage and the minimum voltage difference between the first voltage and the second voltage collected within the i-th detection time; when the absolute value of the second voltage difference between the maximum voltage difference and the minimum voltage difference is less than the second voltage threshold, it is determined that the threshold voltage combination corresponding to the first voltage and the second voltage within the i-th detection time satisfies a preset relationship; when the absolute value of the second voltage difference between the maximum voltage difference and the minimum voltage difference is greater than the second voltage threshold, it is determined that the threshold voltage combination corresponding to the first voltage and the second voltage within the i-th detection time does not satisfy the preset relationship.

[0213] In some embodiments, the threshold voltage combination includes: an initial value of the first voltage and an initial value of the second voltage collected at the start time of a preset diagnostic time, and an end value of the first voltage and an end value of the second voltage collected at the end time of the preset diagnostic time; accordingly, the diagnostic module 1203 is also used to obtain the initial value of the first voltage and the initial value of the second voltage collected at the start time of the preset diagnostic time, and the end value of the first voltage and the end value of the second voltage collected at the end time of the preset diagnostic time when the absolute value of the voltage difference between the first voltage and the second voltage is less than the first voltage threshold and lasts for a first preset time; when the initial value of the first voltage, the end value of the first voltage, the initial value of the second voltage and the end value of the second voltage within the preset diagnostic time satisfy a preset relationship, it is determined that the relay to be tested is in a sticking state.

[0214] In some embodiments, the diagnostic module 1203 is also used to obtain the initial value of the first voltage and the initial value of the second voltage collected at the starting time of the i-th detection time, as well as the ending value of the first voltage and the ending value of the second voltage collected at the ending time of the i-th detection time; when the initial value of the first voltage, the ending value of the first voltage, the initial value of the second voltage and the ending value of the second voltage within the i-th detection time do not satisfy a preset relationship, it is determined that the relay to be tested is in a non-sticky state; when the initial value of the first voltage, the ending value of the first voltage, the initial value of the second voltage and the ending value of the second voltage within the i-th detection time satisfy a preset relationship, perform an i plus one operation until the initial value of the first voltage, the ending value of the first voltage, the initial value of the second voltage and the ending value of the second voltage within N detection times all satisfy the preset relationship, and it is determined that the relay to be tested is in a sticky state.

[0215] In some embodiments, the diagnosis module 1203 is further configured to determine that the relay to be tested is in a non-sticking state when a maximum and minimum voltage relationship between the first voltage and the second voltage within a preset diagnosis time does not satisfy a preset relationship.

[0216] In some embodiments, the diagnostic module 1203 is further configured to determine that the relay to be tested is in a non-sticking state when the second voltage is outside a preset voltage range and lasts for a second preset time.

[0217] It should be noted that those skilled in the art should understand that the relevant description of the relay adhesion diagnosis device 120 in the embodiment of the present application can be understood by referring to the relevant description of the relay adhesion diagnosis method described in the aforementioned embodiment.

[0218] It should also be noted that in the embodiment of the present application, the relay to be tested may include Figure 4 The main positive relay K2 and the main negative relay K3 are shown. Accordingly, the second detection branch 1202 may include a first sampling branch and a second sampling branch, wherein the first sampling branch is used to collect a sampling voltage U3 at both ends of the main negative relay K3 and the battery pack B1 in series, and the second sampling branch is used to collect a sampling voltage U2 at both ends of the main positive relay K2 and the battery pack B1 in series.

[0219] In yet another embodiment of the present application, Fig.13 A schematic diagram of the structure of a relay adhesion diagnosis system provided in an embodiment of the present application. Fig.13 As shown, the relay adhesion diagnosis system 130 may include a circuit to be detected 40 consisting of a battery pack and a relay to be tested, and a relay adhesion diagnosis device 120. The battery pack and the relay to be tested are respectively connected to the relay adhesion diagnosis device 120. The relay adhesion diagnosis device 120 is used to execute the relay adhesion diagnosis method as described in any of the aforementioned embodiments.

[0220] In an embodiment of the present application, after the relay adhesion diagnosis device 120 collects the first voltage at both ends of the battery pack and the second voltage at both ends of the battery pack and the relay to be tested in series, if the absolute value of the voltage difference between the first voltage and the second voltage is less than the first voltage threshold and lasts for a first preset time, and the threshold voltage combination corresponding to the first voltage and the second voltage collected within the preset diagnosis time satisfies the preset relationship, indicating that the voltage change trends on both sides of the relay to be tested are basically the same, then it can be determined that the relay to be tested is in a adhesion state, thereby improving the accuracy of the relay adhesion diagnosis, and being able to take remedial measures in time when a relay adhesion fault is detected; and the double judgment can also improve the robustness of the relay adhesion diagnosis, avoid the problem of misjudgment of adhesion, and thereby improve the circuit reliability.

[0221] In yet another embodiment of the present application, the embodiment of the present application provides a computer-readable storage medium having a computer program stored thereon, and when the computer program is executed, the relay adhesion diagnosis method described in any one of the aforementioned embodiments is implemented.

[0222] In yet another embodiment of the present application, the embodiment of the present application further provides a computer program product, including a computer program or instructions, which, when executed, implements the relay adhesion diagnosis method as described in any one of the aforementioned embodiments.

[0223] It should be noted that the embodiments of the present application may be provided as methods, devices, systems or computer program products. Therefore, the present application may take the form of hardware embodiments, software embodiments, or embodiments combining software and hardware. Moreover, the present application may take the form of a computer program product implemented on one or more computer-readable storage media (including but not limited to disk storage and optical storage, etc.) containing computer-usable program codes.

[0224] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0225] It should also be noted that in this application, the terms "include", "comprises" or any other variants 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 "comprises a ..." does not exclude the presence of other identical elements in the process, method, article or device including the element.

[0226] The serial numbers of the above-mentioned embodiments of the present application are for description only and do not represent the advantages or disadvantages of the embodiments.

[0227] The methods disclosed in several method embodiments provided in this application can be arbitrarily combined without conflict to obtain new method embodiments.

[0228] The features disclosed in several product embodiments provided in this application can be arbitrarily combined without conflict to obtain new product embodiments.

[0229] The features disclosed in several method or device embodiments provided in this application can be arbitrarily combined without conflict to obtain new method embodiments or device embodiments.

[0230] The above description is only a specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application.

Claims

1. A relay adhesion diagnosis method, characterized in that: Applied to a circuit to be tested, the circuit to be tested at least includes a battery pack and a relay to be tested, and the battery pack and the relay to be tested are connected in series; the relay adhesion diagnosis method includes: Detecting a first voltage across the battery pack, and detecting a second voltage across the battery pack connected in series with the relay to be tested; When the absolute value of the voltage difference between the first voltage and the second voltage is less than a first voltage threshold and lasts for a first preset time, acquiring a threshold voltage combination corresponding to the first voltage and the second voltage collected within a preset diagnosis time; When a threshold voltage combination corresponding to the first voltage and the second voltage within the preset diagnosis time satisfies a preset relationship, determining that the relay to be tested is in a sticking state; Wherein, the threshold voltage combination includes: the maximum value of the first voltage, the minimum value of the first voltage, the maximum value of the second voltage and the minimum value of the second voltage; Alternatively, the threshold voltage combination includes: a maximum voltage difference between the first voltage and the second voltage and a minimum voltage difference between the first voltage and the second voltage; Alternatively, the threshold voltage combination includes: an initial value of the first voltage and an initial value of the second voltage collected at the start time of the preset diagnostic time, and an end value of the first voltage and an end value of the second voltage collected at the end time of the preset diagnostic time.

2. The relay adhesion diagnosis method according to claim 1, characterized in that: The preset diagnosis time includes N detection times; The relay adhesion diagnosis method further includes: Acquire a threshold voltage combination corresponding to the first voltage and the second voltage collected within an i-th detection time; When a threshold voltage combination corresponding to the first voltage and the second voltage within the i-th detection time does not satisfy a preset relationship, determining that the relay to be tested is in a non-sticking state; When the threshold voltage combination corresponding to the first voltage and the second voltage in the i-th detection time satisfies a preset relationship, performing an i plus one operation until the threshold voltage combination corresponding to the first voltage and the second voltage in the N detection times all satisfies a preset relationship, determining that the relay to be tested is in a sticking state; Wherein, N is a positive integer, and i is an integer greater than or equal to 1 and less than or equal to N.

3. The relay adhesion diagnosis method according to claim 2, characterized in that: The relay adhesion diagnosis method further includes: determining a first difference between a maximum value of the first voltage and a minimum value of the first voltage and a second difference between a maximum value of the second voltage and a minimum value of the second voltage within an i-th detection time; When an absolute value of a first voltage difference between the first difference and the second difference is less than a second voltage threshold, determining that a threshold voltage combination corresponding to the first voltage and the second voltage within the i-th detection time satisfies a preset relationship; When the absolute value of a first voltage difference between the first difference and the second difference is greater than a second voltage threshold, it is determined that a threshold voltage combination corresponding to the first voltage and the second voltage within the i-th detection time does not satisfy a preset relationship.

4. The relay adhesion diagnosis method according to claim 2, characterized in that: The relay adhesion diagnosis method further includes: Determine a maximum voltage difference between the first voltage and the second voltage and a minimum voltage difference between the first voltage and the second voltage collected within an i-th detection time; When an absolute value of a second voltage difference between the maximum voltage difference and the minimum voltage difference is less than a second voltage threshold, determining that a threshold voltage combination corresponding to the first voltage and the second voltage within the i-th detection time satisfies a preset relationship; When the absolute value of a second voltage difference between the maximum voltage difference and the minimum voltage difference is greater than a second voltage threshold, it is determined that a threshold voltage combination corresponding to the first voltage and the second voltage within the i-th detection time does not satisfy a preset relationship.

5. The relay adhesion diagnosis method according to claim 1, characterized in that: The relay adhesion diagnosis method further includes: When the absolute value of the voltage difference between the first voltage and the second voltage is less than a first voltage threshold and lasts for a first preset time, acquiring an initial value of the first voltage and an initial value of the second voltage collected at a start time of the preset diagnosis time, and an end value of the first voltage and an end value of the second voltage collected at an end time of the preset diagnosis time; When a preset relationship is satisfied among an initial value of the first voltage, an end value of the first voltage, an initial value of the second voltage, and an end value of the second voltage within the preset diagnosis time, it is determined that the relay to be tested is in a sticking state.

6. The relay adhesion diagnosis method according to claim 5, characterized in that: The preset diagnosis time includes N detection times; The relay adhesion diagnosis method further includes: Acquire an initial value of the first voltage and an initial value of the second voltage collected at a start time of an i-th detection time, and an end value of the first voltage and an end value of the second voltage collected at an end time of the i-th detection time; When the initial value of the first voltage, the end value of the first voltage, the initial value of the second voltage and the end value of the second voltage within the i-th detection time do not satisfy a preset relationship, determining that the relay to be tested is in a non-adhesion state; When the initial value of the first voltage, the end value of the first voltage, the initial value of the second voltage and the end value of the second voltage within the i-th detection time satisfy a preset relationship, perform an i plus one operation until the initial value of the first voltage, the end value of the first voltage, the initial value of the second voltage and the end value of the second voltage within the N detection times all satisfy a preset relationship, and determine that the relay to be tested is in a sticking state; Wherein, N is a positive integer, and i is an integer greater than or equal to 1 and less than or equal to N.

7. The relay adhesion diagnosis method according to any one of claims 1 to 6, characterized in that: The relay adhesion diagnosis method further includes: When the maximum and minimum voltage relationship between the first voltage and the second voltage within the preset diagnosis time does not satisfy a preset relationship, it is determined that the relay to be tested is in a non-sticking state.

8. The relay adhesion diagnosis method according to any one of claims 1 to 6, characterized in that: The relay adhesion diagnosis method further includes: When the second voltage is outside the preset voltage range and lasts for a second preset time, it is determined that the relay to be tested is in a non-sticking state.

9. A relay adhesion diagnosis device, characterized in that: Applied to a circuit to be tested, the circuit to be tested at least includes a battery pack and a relay to be tested, and the battery pack and the relay to be tested are connected in series; the relay adhesion diagnosis device includes: A first detection branch connected between a first end of the battery pack and a second end of the battery pack, and configured to detect a first voltage across the battery pack; A second detection branch, wherein the second detection branch is connected between the second end of the battery pack and the second end of the relay to be tested, and is used to detect a second voltage between the two ends of the battery pack and the relay to be tested in series; A diagnostic module, configured to obtain a threshold voltage combination corresponding to the first voltage and the second voltage collected within a preset diagnostic time when the absolute value of the voltage difference between the first voltage and the second voltage is less than a first voltage threshold value and lasts for a first preset time; and to determine that the relay to be tested is in a sticking state when the threshold voltage combination corresponding to the first voltage and the second voltage within the preset diagnostic time satisfies a preset relationship; Wherein, the threshold voltage combination includes: the maximum value of the first voltage, the minimum value of the first voltage, the maximum value of the second voltage and the minimum value of the second voltage; Alternatively, the threshold voltage combination includes: a maximum voltage difference between the first voltage and the second voltage and a minimum voltage difference between the first voltage and the second voltage; Alternatively, the threshold voltage combination includes: an initial value of the first voltage and an initial value of the second voltage collected at the start time of the preset diagnostic time, and an end value of the first voltage and an end value of the second voltage collected at the end time of the preset diagnostic time.

10. The relay adhesion diagnosis device according to claim 9, characterized in that: The preset diagnosis time includes N detection times; The diagnostic module is further used to obtain a threshold voltage combination corresponding to the first voltage and the second voltage collected within the i-th detection time when the absolute value of the voltage difference between the first voltage and the second voltage is less than a first voltage threshold and lasts for a first preset time; and to determine that the relay to be tested is in a non-sticky state when the threshold voltage combination corresponding to the first voltage and the second voltage within the i-th detection time does not satisfy a preset relationship; wherein N is a positive integer, and i is an integer greater than or equal to 1 and less than or equal to N.

11. The relay adhesion diagnosis device according to claim 10, characterized in that: The diagnostic module is also used to perform an i plus one operation when a threshold voltage combination corresponding to the first voltage and the second voltage within the i-th detection time satisfies a preset relationship, until the threshold voltage combinations corresponding to the first voltage and the second voltage within the N detection times all satisfy the preset relationship, thereby determining that the relay to be tested is in a sticking state.

12. A relay adhesion diagnosis system, characterized in that: The relay adhesion diagnosis system includes a circuit to be detected consisting of a battery pack and a relay to be tested, and a relay adhesion diagnosis device, wherein the battery pack and the relay to be tested are respectively connected to the relay adhesion diagnosis device, and the relay adhesion diagnosis device is used to execute the relay adhesion diagnosis method as described in any one of claims 1 to 8.

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