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 at least includes a series branch composed of a battery pack and a relay to be detected, and the equivalent capacitance of the circuit to be detected is greater than a preset capacitance; the relay adhesion diagnosis method includes: collecting the voltage difference between the two ends of the relay to be tested; when the voltage difference meets the first preset condition, obtaining two sampled voltages corresponding to the series branch collected within the preset diagnosis time; when the absolute value of the voltage difference between the two sampled voltages within the preset diagnosis time meets the second preset condition, determining that the relay to be tested is in a adhesion state. In this way, the robustness of the 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 special cases, the sampling voltage drops slowly, which can easily misreport a relay adhesion fault during voltage detection, 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 false positive 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, characterized in that it is applied to a circuit to be detected, the circuit to be detected at least includes a series branch consisting of a battery pack and a relay to be detected, and the equivalent capacitance of the circuit to be detected is greater than a preset capacitance; the relay adhesion diagnosis method includes:

[0007] Collect the voltage difference between the two ends of the relay to be tested;

[0008] When the voltage difference satisfies the first preset condition, two sampled voltages corresponding to the series branches collected within a preset diagnosis time are obtained;

[0009] When the absolute value of the voltage difference between the two sampled voltages within the preset diagnosis time satisfies a second preset condition, it is determined that the relay to be tested is in a sticking state.

[0010] Through the above technical means, after the voltage difference at both ends of the relay to be tested is collected, a preliminary judgment is first made based on whether the voltage difference meets the first preset condition, and then a further judgment is made based on whether the absolute value of the voltage difference between the two sampled voltages collected within the preset diagnostic time meets the second preset condition. In this way, since the equivalent capacitance of the circuit to be detected is greater than the preset capacitance (for example, several hundred nanofarads), the sampled voltage at the rear end of the relay to be tested drops relatively slowly, and when judging whether the voltage difference meets the first preset condition, a phenomenon of relay adhesion misjudgment is prone to occur; therefore, after the voltage difference at both ends of the relay to be tested is collected, a preliminary judgment is first made based on whether the voltage difference meets the first preset condition. Pre-judgment is made, when the voltage difference satisfies the first preset condition, and then further judgment is made based on whether the absolute value of the voltage difference between the two sampled voltages corresponding to the series branch collected within the preset diagnostic time meets the second preset condition. If the voltage drop between the two sampled voltages within the preset diagnostic time meets the second preset condition, then it can be determined that the relay to be tested is in a sticking state, thereby avoiding the problem of misjudgment of relay sticking due to the excessive equivalent capacitance of the circuit to be tested, 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, thereby improving circuit reliability.

[0011] In some embodiments, the two sampled voltages include: a maximum value and a minimum value of the sampled voltages collected within a preset diagnosis time.

[0012] Through the above-mentioned technical means, the maximum and minimum values ​​of the sampled voltages collected within the preset diagnostic time are used to judge whether the absolute value of the voltage difference between the two sampled voltages collected within the preset diagnostic time meets the second preset condition, so as to accurately determine whether the relay to be tested is in a sticking state, thereby avoiding the problem of misjudgment of sticking.

[0013] In some embodiments, the preset diagnostic time includes N detection times, and the relay adhesion diagnosis method also includes: obtaining the maximum and minimum values ​​of the sampled voltage collected within the i-th detection time; when the absolute value of the voltage difference between the maximum and minimum values ​​of the sampled voltage within the i-th detection time does not meet the second preset condition, determining that the relay to be tested is in a non-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.

[0014] Through the above technical means, taking the i-th detection time as an example, if the absolute value of the voltage difference between the maximum and minimum values ​​of the sampled voltage collected during the detection time does not meet the second preset condition, it can be determined that the relay to be tested is in a non-adhesive state, and the relay adhesion diagnosis process is directly exited at this time. Therefore, multiple quick inspections can be performed within the preset diagnosis time, which can not only shorten the diagnosis time and achieve adaptive quick detection, but also detect whether the relay has an adhesion fault in a timely manner. At the same time, double judgment can also avoid the problem of misjudgment of adhesion.

[0015] In some embodiments, the relay sticking diagnosis method further includes: when the absolute value of the voltage difference between the maximum value and the minimum value of the sampling voltage within the i-th detection time satisfies a second preset condition, performing an i plus one operation, until the absolute value of the voltage difference between the maximum value and the minimum value of the sampling voltage within N detection times all satisfies the second preset condition, and it is determined that the relay to be tested is in a sticking state.

[0016] Through the above technical means, still taking the i-th detection time as an example, if the absolute value of the voltage difference between the maximum value and the minimum value of the sampled voltage collected in the i-th detection time meets the second preset condition, then continue to judge whether the absolute value of the voltage difference between the maximum value and the minimum value of the sampled voltage collected in the next detection time meets the second preset condition, until the absolute value of the voltage difference between the maximum value and the minimum value of the sampled voltage in N detection times meets the second preset condition, 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. At the same time, double judgment can also avoid the problem of misjudgment of sticking.

[0017] In some embodiments, the two sampled voltages include: an initial value of the sampled voltage collected at a start time of a preset diagnosis time and an end value of the sampled voltage collected at an end time of the preset diagnosis time.

[0018] Through the above-mentioned technical means, the initial value and the end value of the sampled voltage collected within the preset diagnostic time are used to judge whether the absolute value of the voltage difference between the two sampled voltages collected within the preset diagnostic time meets the second preset condition, so as to accurately determine whether the relay to be tested is in a sticking state, thereby avoiding the problem of misjudgment of sticking.

[0019] In some embodiments, the preset diagnostic time includes N detection times; the relay adhesion diagnosis method also includes: obtaining the initial value of the sampled voltage collected at the start time of the i-th detection time, and the end value of the sampled voltage collected at the end time of the i-th detection time; when the absolute value of the voltage difference between the initial value and the end value of the sampled voltage within the i-th detection time does not meet the second preset condition, determining that the relay to be tested is in a non-adhesion state; when the absolute value of the voltage difference between the initial value and the end value of the sampled voltage within the i-th detection time meets the second preset condition, performing an i plus one operation until the absolute value of the voltage difference between the initial value and the end value of the sampled voltage within N detection times all meet the second preset condition, 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.

[0020] Through the above-mentioned technical means, still taking the i-th detection time as an example, it can be determined whether the absolute value of the voltage difference between the end value and the initial value of the sampling voltage within the detection time satisfies the second preset condition to determine whether the relay to be tested is in a sticking state; if the absolute value of the voltage difference between the end value and the initial value of the sampling voltage within the detection time does not meet the second preset condition, 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; if the absolute value of the voltage difference between the end value and the initial value of the sampling voltage within the current detection time meets the second preset condition, then the sticking judgment of the next detection time can be performed; thereby, multiple quick inspections can be performed within the preset diagnosis time, and adaptive quick detection can be realized, so as to timely detect whether the relay has a sticking fault; 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.

[0021] In some embodiments, the first preset condition is used to indicate that the voltage difference across the relay to be tested is less than a first voltage threshold and lasts for a first preset time, and the second preset condition is used to indicate that the absolute value of the voltage difference between the two sampled voltages is less than a second voltage threshold.

[0022] Through the above-mentioned technical means, a preliminary judgment is made based on whether the voltage difference across the relay to be tested 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 absolute value of the voltage difference between the two sampled voltages is less than the second voltage threshold. If the voltage difference across the relay to be tested is less than the first voltage threshold and lasts for the first preset time, and the absolute value of the voltage difference between the two sampled voltages is less than the second voltage threshold, then it can be determined that the relay to be tested is in a sticking state, thereby improving the accuracy of relay sticking diagnosis.

[0023] In some embodiments, the relay sticking diagnosis method further includes: determining that the relay to be tested is in a non-sticking state when a first sampled voltage collected within a preset diagnosis time is outside a preset voltage range and lasts for a second preset time.

[0024] Through the above-mentioned technical means, the first sampling voltage represents the sampling voltage at both ends of the series branch composed of the battery pack and the relay to be tested, which is collected at a certain moment within the preset diagnostic time. If the first sampling voltage collected within the preset diagnostic time is not within the preset voltage range and lasts for a 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's sticking diagnosis process can be exited, thereby shortening the diagnosis time and avoiding the problem of misjudgment of sticking.

[0025] In some embodiments, the relay sticking diagnosis method further includes: when the absolute value of the voltage difference between the two sampled voltages does not satisfy a second preset condition within a preset diagnosis time, determining that the relay to be tested is in a non-sticking state.

[0026] Through the above-mentioned technical means, if the absolute value of the voltage difference between the two sampling voltages within the preset diagnostic time does not meet the second preset condition, 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. In addition, 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.

[0027] 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 series branch consisting of a battery pack and a relay to be detected, and the equivalent capacitance of the circuit to be detected is greater than a preset capacitance; the relay adhesion diagnosis device includes:

[0028] A collection branch, the collection branch is connected to the circuit to be detected, and is used to collect the voltage difference between the two ends of the relay to be tested, and to collect the sampling voltage corresponding to the series branch within a preset diagnosis time;

[0029] A diagnostic branch, which is connected to the acquisition branch, is used to obtain two sampled voltages corresponding to the series branch acquired within a preset diagnostic time when the voltage difference meets a first preset condition; and to determine that the relay to be tested is in a sticky state when the absolute value of the voltage difference between the two sampled voltages within the preset diagnostic time meets a second preset condition.

[0030] Through the above-mentioned technical means, the relay adhesion diagnostic device includes a collection branch and a diagnostic branch; wherein the collection branch is connected to the circuit to be detected, and at this time the collection branch can be used to collect the voltage difference between the two ends of the relay to be tested, as well as the sampled voltage corresponding to the series branch within the preset diagnostic time; the diagnostic branch is connected to the collection branch, and at this time the diagnostic branch first makes a preliminary judgment based on whether the voltage difference between the two ends of the relay to be tested meets the first preset condition, and then makes a further judgment based on whether the absolute value of the voltage difference between the two sampled voltages collected within the preset diagnostic time meets the second preset condition. In this way, since the equivalent capacitance of the circuit to be detected is greater than the preset capacitance (for example, several hundred nanofarads), the sampled voltage at the rear end of the relay to be tested drops relatively slowly, and relay adhesion errors are prone to occur when judging whether the voltage difference meets the first preset condition. Therefore, after collecting the voltage difference between the two ends of the relay to be tested, a preliminary judgment is first made based on whether the voltage difference satisfies the first preset condition. When the voltage difference satisfies the first preset condition, a further judgment is made based on whether the absolute value of the voltage difference between the two sampled voltages corresponding to the series branch collected within the preset diagnostic time satisfies the second preset condition. If the voltage drop between the two sampled voltages within the preset diagnostic time satisfies the second preset condition, it can be determined that the relay to be tested is in a sticking state, thereby avoiding the problem of misjudgment of relay sticking due to the excessive equivalent capacitance of the circuit to be detected, 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, thereby improving circuit reliability.

[0031] In some embodiments, the preset diagnostic time includes N detection times: a diagnostic branch is also used to obtain the maximum and minimum values ​​of the sampled voltage collected within the i-th detection time; when the voltage difference between the maximum and minimum values ​​of the sampled voltage within the i-th detection time does not satisfy a second preset relationship, it is determined 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.

[0032] Through the above technical means, taking the i-th detection time as an example, if the diagnostic branch determines that the absolute value of the voltage difference between the maximum and minimum values ​​of the sampled voltage collected during the detection time does not satisfy the second preset relationship, it can be determined that the relay to be tested is in a non-adhesive state, and the relay adhesion diagnosis process is directly exited at this time. Therefore, multiple quick inspections can be performed within the preset diagnostic time, which can not only shorten the diagnostic time and achieve adaptive quick detection, but also detect whether the relay has an adhesion fault in a timely manner. At the same time, double judgment can also avoid the problem of misjudgment of adhesion.

[0033] 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.

[0034] Through the above-mentioned technical means, since the relay adhesion diagnosis system includes a relay adhesion diagnosis device, after the acquisition branch acquires the voltage difference across the relay to be tested, and acquires the sampled voltage corresponding to the series branch within the preset diagnosis time, the diagnosis branch first makes a preliminary judgment based on whether the voltage difference across the relay to be tested meets the first preset condition, and then makes a further judgment based on whether the absolute value of the voltage difference between the two sampled voltages acquired within the preset diagnosis time meets the second preset condition. In this way, since the equivalent capacitance of the circuit to be detected is greater than the preset capacitance (for example, several hundred nanofarads), the sampled voltage at the rear end of the relay to be tested drops relatively slowly, and when judging whether the voltage difference meets the first preset condition, it is easy to make a misjudgment of relay adhesion. Therefore, when the voltage difference across the relay to be tested is acquired, After obtaining the voltage difference, a preliminary judgment is first made based on whether the voltage difference satisfies a first preset condition. If the voltage difference satisfies the first preset condition, a further judgment is then made based on whether the absolute value of the voltage difference between the two sampled voltages corresponding to the series branch collected within the preset diagnostic time satisfies a second preset condition. If the voltage drop between the two sampled voltages within the preset diagnostic time satisfies the second preset condition, it can be determined that the relay to be tested is in a sticking state, thereby avoiding the problem of misjudgment of relay sticking due to excessive equivalent capacitance of the circuit to be tested, improving the accuracy of relay sticking diagnosis, and being able to take remedial measures in time when a relay sticking fault is detected. Moreover, the double judgment can also improve the robustness of the relay sticking diagnosis, thereby improving the circuit reliability.

[0035] 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

[0036] Figure 1 It is a schematic diagram of the architecture of the relay sticking diagnosis circuit;

[0037] Figure 2 It is a schematic diagram of the Y capacitor equivalent circuit of the relay adhesion diagnosis circuit;

[0038] Figure 3 A schematic diagram of the measured data of the sampling voltage corresponding to the main positive relay and the main negative relay;

[0039] Figure 4A schematic diagram of the structure of a circuit to be detected provided in an embodiment of the present application;

[0040] Figure 5 A schematic diagram of a relay adhesion diagnosis method provided in an embodiment of the present application Figure 1 ;

[0041] Figure 6 A schematic diagram of a relay adhesion diagnosis method provided in an embodiment of the present application Figure 2 ;

[0042] Figure 7 A schematic diagram of a relay adhesion diagnosis method provided in an embodiment of the present application Figure 3 ;

[0043] Figure 8 A schematic diagram of a relay adhesion diagnosis method provided in an embodiment of the present application Figure 4 ;

[0044] Fig. 9 A timing diagram of a relay adhesion diagnosis to be tested provided in an embodiment of the present application;

[0045] Fig.10 A schematic diagram of a variation trend of a sampling voltage provided in an embodiment of the present application;

[0046] Fig.11 A schematic diagram of the structure of a relay adhesion diagnosis device provided in an embodiment of the present application;

[0047] Fig.12 A schematic diagram of the composition structure of a relay adhesion diagnosis system provided in an embodiment of the present application. DETAILED DESCRIPTION

[0048] 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.

[0049] 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.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] The following is an introduction to the related technologies of this application.

[0054] 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 areas such as energy storage.

[0055] 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.

[0056] 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 continuously used by activating the active material by charging after the battery cell is discharged. 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 in the embodiments of the present disclosure.

[0057] 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.

[0058] 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.

[0059] 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.

[0060] 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 acquisition branch corresponding to U2 and U3 becomes larger, see Figure 2 shown.

[0061] 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 acquisition branch may include a first acquisition branch and a second acquisition branch. The first acquisition branch may be used to acquire the battery voltage of the battery pack B1, i.e., the voltage U1 across the battery pack B1. The second acquisition branch may include a second first acquisition branch and a second second acquisition branch. Figure 2As shown, the second first acquisition branch includes a first switch EN3, a third resistor R3 and a fourth resistor R4, which are used to acquire a sampled voltage U3 at both ends of the main negative relay K3 and the battery pack B1 in series, and the second second acquisition branch includes a second switch EN2, a fifth resistor R5 and a sixth resistor R6, which are used to acquire a sampled 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 second first acquisition branch, and a second equivalent capacitor C2 is connected in parallel at both ends of the second second acquisition branch.

[0062] 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.

[0063] 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.

[0064] 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.

[0065] 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 or U3 will decrease slowly.

[0066] 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.

[0067] That is, 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 acquisition branch corresponding to U2 and U3 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.

[0068] Based on this, the embodiments of the present application provide a relay adhesion diagnosis method, device and system, which first collects the voltage difference between the two ends of the relay to be tested; then, when the voltage difference meets the first preset condition, obtains the two sampled voltages corresponding to the series branch collected within the preset diagnostic time; then, when the absolute value of the voltage difference between the two sampled voltages collected within the preset diagnostic time meets the second preset condition, determines that the relay to be tested is in a adhesion state. In this way, after collecting the voltage difference between the two ends of the relay to be tested, firstly make a preliminary judgment based on whether the voltage difference meets the first preset condition, and then make a further judgment based on whether the absolute value of the voltage difference between the two sampled voltages collected within the preset diagnostic time meets the second preset condition. In this way, since the equivalent capacitance of the circuit to be detected is greater than the preset capacitance (for example, a few hundred nanofarads), the sampled voltage at the rear end of the relay to be tested drops relatively slowly, and when judging based on whether the voltage difference meets the first preset condition, it is easy to make a misjudgment of relay adhesion; therefore, after collecting the voltage difference between the two ends of the relay to be tested, firstly make a preliminary judgment based on whether the voltage difference meets the first preset condition. A condition is set to make a preliminary judgment. When the voltage difference meets the first preset condition, and then further judgement is made based on whether the absolute value of the voltage difference between the two sampled voltages corresponding to the series branch collected within the preset diagnosis time meets the second preset condition. 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 avoiding the problem of misjudgment of relay sticking due to the excessive equivalent capacitance of the circuit to be detected, 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, thereby improving the reliability of the circuit.

[0069] The present application is further described in detail below through the accompanying drawings and specific embodiments.

[0070] 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 include at least: a battery pack B1 and a relay to be tested, and the battery pack B1 and the relay to be tested form a series branch. Figure 4 One of the pre-charge relay K1, main positive relay K2 and main negative relay K3 shown.

[0071] 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.

[0072] 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 As 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 battery voltage corresponding to the battery pack B1, that is, the voltage corresponding to the two ends of the battery pack B1, U2 is the sampling voltage corresponding to the two ends of the series branch composed of the battery pack B1 and the main positive relay K2, and U3 is the sampling voltage corresponding to the two ends of the series branch composed of the battery pack B1 and the main negative relay K3.

[0073] 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.

[0074] 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.

[0075] 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; 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.

[0076] 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 may include:

[0077] S501, collecting the voltage difference between the two ends of the relay to be tested.

[0078] 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.

[0079] 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.

[0080] In some embodiments, collecting the voltage difference across the relay to be tested includes: collecting the battery voltage of the battery pack and collecting the sampled voltage corresponding to the series branch; and determining the voltage difference across the relay to be tested based on the battery voltage and the sampled voltage.

[0081] In the embodiment of the present application, the battery voltage can be referred to as the first voltage, which can be represented by V1, and can be obtained by sampling the voltage at both ends of the battery pack by the acquisition branch; the sampled voltage can be referred to as the second voltage, which can be represented by V2, and can be obtained by sampling the voltage at both ends of the series branch formed by the battery pack and the relay to be tested by the acquisition branch. In the embodiment of the present application, the relay to be tested can include the main positive relay K2 and / or the main negative relay K3. For example, Figure 4 For example, the battery voltage V1 can be Figure 4 U1 in the figure is the voltage corresponding to both ends of the battery pack B1; when the relay to be tested is the main positive relay K2, the sampling voltage V2 can be Figure 4 U2 in the figure is the sampling voltage at both ends of the series branch composed of the battery pack B1 and the main positive relay K2; when the relay to be tested is the main negative relay K3, the sampling voltage V2 can be Figure 4 U3 in the figure is the sampling voltage corresponding to the two ends of the series branch composed of the battery pack B1 and the main negative relay K3.

[0082] S502, when the voltage difference satisfies a first preset condition, obtaining two sampled voltages corresponding to the series branches collected within a preset diagnosis time.

[0083] It should be noted that in the embodiment of the present application, the equivalent capacitance of the circuit to be detected is greater than the preset capacitance. The preset capacitance here is a measure for judging whether the equivalent capacitance of the circuit to be detected is too large. Exemplarily, the preset capacitance can be set to several hundred nF, but is not specifically limited.

[0084] It should also be noted that, in the embodiment of the present application, the sampling voltage corresponding to the series branch may refer to the sampling voltage at the rear end of the relay to be tested. Since the equivalent capacitance of the circuit to be tested is greater than the preset capacitance, the sampling voltage at the rear end of the relay to be tested decreases slowly, and when the relay adhesion judgment is performed based on whether the voltage difference between the two ends of the relay to be tested meets the first preset condition, the phenomenon of relay adhesion misjudgment is prone to occur.

[0085] Exemplarily, when performing relay adhesion diagnosis, the voltage difference between the two ends of the relay to be tested is obtained in the relevant technology to determine whether the voltage difference is less than a certain threshold value. If the voltage difference is less than a certain threshold value, it is determined that the relay to be tested is in a state of adhesion. However, since the equivalent capacitance of the circuit to be tested is greater than the preset capacitance, that is, the equivalent capacitance of the circuit to be tested is too large, the sampled voltage at the rear end of the relay to be tested drops slowly. By judging whether the voltage difference between the two ends of the relay meets the first preset condition, it is not possible to determine that the relay to be tested is adhered. Therefore, it is necessary to further obtain the two sampled voltages corresponding to the series branch collected within the preset diagnostic time, and then make further judgments based on the voltage drop within the preset diagnostic time.

[0086] In the embodiment of the present application, a preset diagnostic time can be set here, and the size of the preset diagnostic time can be obtained by adding the minimum sampling time to the margin time. In other words, the preset diagnostic time can be represented by T, which is the minimum sampling time required for the drop to be greater than a certain threshold value calculated based on the size of the Y capacitor 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 diagnostic time is greater than a certain threshold value.

[0087] In some embodiments, the first preset condition is used to indicate that the voltage difference between the two ends of the relay to be tested is less than a first voltage threshold and lasts for a first preset time.

[0088] In the embodiment of the present application, judging whether the voltage difference between the two ends of the relay to be tested is less than the first voltage threshold and lasts for the first preset time can be performed within a preset diagnosis time. That is, if the voltage difference between the two ends of the relay to be tested is less than the first voltage threshold and lasts for the first preset time within the preset diagnosis time, it can be determined that the relay to be tested may be stuck.

[0089] In addition, in the embodiments of the present application, when the relay under test is in an adhesive state, in a rational situation, the sampling voltage corresponding to the series branch is equal to the battery voltage. However, due to factors such as measurement error, the internal resistance of the battery pack, the internal resistance of the relay under test, and the accuracy of the measurement device, the sampling voltage may not be equal to the battery voltage. Therefore, it is determined whether the relay under test is adhesive by whether the absolute value of the voltage difference between the battery voltage and the sampling voltage (i.e., the voltage difference across the relay under test) is less than a certain threshold. Here, the voltage difference across the relay under test is the absolute value of the voltage difference between the battery voltage and the sampling voltage, which can be represented by |V1 - V2|, and the first voltage threshold can be represented by Vth1. In this way, for the voltage difference across the relay under test to be less than the first voltage threshold, it can mean |V1 - V2| < Vth1.

[0090] That is to say, if |V1 - V2| < Vth1 and lasts for the first preset time within the preset diagnosis time, it can be determined that the relay under test may be adhesive. At this time, further adhesive diagnosis is required, and two sampling voltages corresponding to the series branch collected within the preset diagnosis time are obtained for further judgment.

[0091] Exemplarily, the first voltage threshold can be set to 5% * V1, and the first preset time can be set to 700 ms. Thus, if |V1 - V2| < 5% * V1 and lasts for 700 ms, it can be determined that the relay under test may be adhesive. At this time, two sampling voltages corresponding to the series branch collected within the preset diagnosis time are obtained for further judgment for further adhesive diagnosis.

[0092] S503, when the absolute value of the voltage difference between the two sampling voltages within the diagnosis time satisfies the second preset condition, it is determined that the relay under test is in an adhesive state.

[0093] In the embodiments of the present application, the second preset condition is used to represent that the absolute value of the voltage difference between the two sampling voltages is less than the second voltage threshold.

[0094] In the embodiments of the present application, the sampling voltage here refers to the sampling voltage at the rear end of the relay under test, and the two sampling voltages refer to the sampling voltages collected at different times within the preset diagnosis time. Among them, the two sampling voltages can be represented by V21 and V22, and the absolute value of the voltage between the two sampling voltages can be represented by |V21 - V22|. The second voltage threshold can be represented by Vth2. Then here, it is judged whether |V21 - V22| is less than Vth2. Exemplarily, the value of Vth2 can be set to 10 V, but there is no limitation.

[0095] In addition, for the two sampling voltages corresponding to the series branch within the preset diagnostic time, they can be any two values ​​of the sampling voltages corresponding to the series branch collected within the preset diagnostic time, or they can be the initial value of the sampling voltage collected at the start time of the preset diagnostic time and the end value of the sampling voltage collected at the end time of the preset diagnostic time, or they can be the maximum value and minimum value of the sampling voltages corresponding to the series branch collected within the preset diagnostic time, and there is no specific limitation on this.

[0096] It should also be noted that when obtaining two sampled voltages corresponding to the series branch collected within the preset diagnostic time, it can be periodic or non-periodic collection within the preset diagnostic time, and then the sampled voltages corresponding to the series branch obtained at two different times are selected, and whether the relay to be tested is stuck is further determined based on the voltage drop between the two sampled voltages. It should be understood that the preset diagnostic time may include multiple sampling moments, and the sampling moments may be set at equal intervals (for example, 10ms is a sampling moment, 20ms is a sampling moment), or may be set at unequal intervals (for example, 10ms is a sampling moment, 15ms is a sampling moment); the sampling moments here can be set according to actual conditions, and no limitation is imposed on this.

[0097] In some embodiments, the relay sticking diagnosis method further includes: when the absolute value of the voltage difference between the two sampled voltages does not satisfy a second preset condition within a preset diagnosis time, determining that the relay to be tested is in a non-sticking state.

[0098] In an embodiment of the present application, if the absolute value of the voltage difference between the two sampling voltages within the preset diagnostic time does not meet the second preset condition, 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. In addition, 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.

[0099] 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.

[0100] The embodiment of the present application provides a relay adhesion diagnosis method, which firstly performs a preliminary judgment based on whether the voltage difference satisfies a first preset condition after the voltage difference value at both ends of the relay to be tested is collected, and then further judges based on whether the absolute value of the voltage difference between the two sampled voltages collected within the preset diagnosis time satisfies a second preset condition. In this way, since the equivalent capacitance of the circuit to be tested is greater than the preset capacitance (for example, several hundred nanofarads), the sampled voltage at the rear end of the relay to be tested drops relatively slowly, and the phenomenon of relay adhesion misjudgment is prone to occur when judging based on whether the voltage difference value satisfies the first preset condition. Therefore, after the voltage difference value at both ends of the relay to be tested is collected, firstly performs a preliminary judgment based on whether the voltage difference value satisfies a second preset condition. The first preset condition is used for preliminary judgment. When the voltage difference meets the first preset condition, further judgment is made based on whether the absolute value of the voltage difference between the two sampled voltages collected within the preset diagnostic time meets the second preset condition. If the voltage drop between the two sampled voltages within the preset diagnostic time meets the second preset condition, it can be determined that the relay to be tested is in a sticking state, thereby avoiding the problem of misjudgment of relay sticking due to excessive equivalent capacitance of the circuit to be tested, 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, thereby improving circuit reliability.

[0101] 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.

[0102] 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.

[0103] 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 disconnected after the relay to be tested is disconnected. It should also be noted that, considering that the acquisition 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 acquisition branch is completed, and a valid sampling voltage can be acquired at this time.

[0104] 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.

[0105] In an embodiment of the present application, the relay adhesion diagnosis method also includes: obtaining two sampled voltages corresponding to the series branch collected within the i-th detection time; when the absolute value of the voltage difference between the two sampled voltages within the i-th detection time does not meet the second preset condition, determining that the relay to be tested is in a non-adhesion state; when the absolute value of the voltage difference between the two sampled voltages within the i-th detection time meets the second preset condition, performing an i plus one operation until the absolute value of the voltage difference between the initial value and the end value of the sampled voltage within N detection times meets the second preset condition, 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.

[0106] In an embodiment of the present application, the preset diagnostic time can be divided into multiple detection times. If the absolute value of the voltage difference between two sampled voltages collected within a certain detection time does not meet the second preset condition, it can be directly determined that the relay to be tested is in a non-sticky state. At this time, the relay sticking diagnosis process is directly exited, thereby shortening the diagnosis time and realizing adaptive rapid detection.

[0107] In some embodiments, the two sampled voltages include: a maximum value and a minimum value of the sampled voltages collected within a preset diagnosis time.

[0108] In the embodiment of the present application, within the preset diagnosis time, the maximum value of the sampled voltage can be represented by V2max, and the minimum value of the sampled voltage can be represented by V2min. The absolute value of the voltage difference between the maximum value and the minimum value of the sampled voltage within the preset diagnosis time can be represented by |V2max-V2min|.

[0109] In some embodiments, the relay sticking diagnosis method may further include:

[0110] Obtain the maximum and minimum values ​​of the sampled voltage collected within the i-th detection time; when the absolute value of the voltage difference between the maximum and minimum values ​​of the sampled voltage within the i-th detection time does not meet the second preset condition, determine that the relay to be tested is in a non-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.

[0111] That is to say, in the embodiment of the present application, if the absolute value of the voltage difference between the maximum and minimum values ​​of the sampled voltage collected within a certain detection time does not meet the second preset condition (that is, the absolute value of the voltage difference between the maximum and minimum values ​​of the sampled voltage within the fast detection time is greater than the second voltage threshold), it can be determined that the relay to be tested is in a non-adhesive state, and the relay adhesion diagnosis process is directly exited at this time. Therefore, multiple fast inspections can be performed within the preset diagnostic time, which can not only shorten the diagnosis time and realize adaptive fast detection, but also detect whether the relay has an adhesion fault in time. At the same time, double judgment can also avoid the problem of misjudgment of adhesion.

[0112] In some embodiments, the relay sticking diagnosis method may further include: when the absolute value of the voltage difference between the maximum value and the minimum value of the sampling voltage within the i-th detection time satisfies a second preset condition, performing an i plus one operation, until the absolute value of the voltage difference between the maximum value and the minimum value of the sampling voltage within N detection times all satisfies the second preset condition, and determining that the relay to be tested is in a sticking state.

[0113] That is to say, in the embodiment of the present application, taking the i-th detection time as an example, if the absolute value of the voltage difference between the maximum value and the minimum value of the sampled voltage collected in the i-th detection time satisfies the second preset condition (i.e., the absolute value of the voltage difference between the maximum value and the minimum value of the sampled voltage in the fast detection time is less than the second voltage threshold), then continue to judge whether the absolute value of the voltage difference between the maximum value and the minimum value of the sampled voltage collected in the next detection time satisfies the second preset condition, until the absolute value of the voltage difference between the maximum value and the minimum value of the sampled voltage in N detection times all satisfies the second preset condition, 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, double judgment can also avoid the problem of misjudgment of sticking.

[0114] In one possible embodiment, 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:

[0115] S601, when the voltage difference across the relay to be tested is less than a first voltage threshold and lasts for a first preset time, obtaining the maximum and minimum values ​​of the sampled voltages collected within an i-th detection time.

[0116] S602, determining whether the absolute value of the voltage difference between the maximum value and the minimum value of the sampling voltage within the i-th detection time is less than a second voltage threshold.

[0117] S603, determining that the relay to be tested is in a non-sticky state.

[0118] S604, i=i+1.

[0119] S605: When the absolute value of the voltage difference between the maximum value and the minimum value of the sampled voltage within the N detection times is less than the second voltage threshold, it is determined that the relay to be tested is in a sticking state.

[0120] In the embodiment of the present application, for step S602, if the judgment result is no, that is, |V2max-V2min| is greater than the second voltage threshold within the i-th detection time, then step S603 can be executed; if the judgment result is yes, that is, |V2max-V2min| is less than the second voltage threshold within the i-th detection time, then step S604 can be executed, that is, i is executed to add one, and return to step S602 to determine whether |V2max-V2min| is less than the second voltage threshold within the next detection time. Until i is equal to N, if |V2max-V2min| is less than the second voltage threshold within N detection times, it is determined that the relay to be tested is in a sticking state.

[0121] In addition, in the embodiment of the present application, if |V2max-V1min| is less than Vth2, then it can be determined that the relay to be tested is in a sticking state; if |V2max-V1min| is greater than Vth2, then it can be determined that the relay to be tested is in a non-sticking state. In addition, for the case where |V2max-V1min| is equal to Vth2, then it can be determined that the relay to be tested is in a sticking state, or it can also be determined that the relay to be tested is in a non-sticking state, and no limitation is made here.

[0122] Thus, in the embodiment of the present application, if the absolute value of the voltage difference between the maximum value and the minimum value of the sampling voltage within a certain detection time is greater than the second voltage threshold, it can be determined that the relay to be tested is in a non-adhesive state, and the relay adhesion diagnosis process is directly exited at this time; otherwise, if the absolute value of the voltage difference between the maximum value and the minimum value of the sampling voltage within a certain detection time is less than the second voltage threshold, it is continued to determine whether the absolute value of the voltage difference between the maximum value and the minimum value of the sampling voltage within the next detection time is greater than the second voltage threshold, until the absolute value of the voltage difference between the maximum value and the minimum value of the sampling voltage within N detection times is less than the second voltage threshold, it is determined that the relay to be tested is in an 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.

[0123] In some embodiments, the initial value of the sampled voltage collected at the start time of the preset diagnosis time and the end value of the sampled voltage collected at the end time of the preset diagnosis time are preset.

[0124] It should be noted that at the beginning of the preset diagnosis time, the initial value of the sampled voltage collected is represented by V2init; at the end of the preset diagnosis time, the final value of the sampled voltage collected can be represented by V2final.

[0125] It should also be noted that the absolute value of the voltage difference between the initial value of the sampling voltage and the final value of the sampling voltage within the preset diagnosis time can be represented by |V2final-V2init|, and the second voltage threshold can be represented by Vth2.

[0126] In another possible implementation, 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:

[0127] S701, when the voltage difference across the relay to be tested satisfies a first preset relationship, obtaining an initial value of the sampled voltage collected at the start time of a preset diagnosis time, and an end value of the sampled voltage collected at the end time of the preset diagnosis time.

[0128] S702: When the absolute value of the voltage difference between the initial value and the end value of the sampled voltage within the preset diagnosis time satisfies a second preset condition, it is determined that the relay to be tested is in a sticking state.

[0129] S703: When the absolute value of the voltage difference between the initial value and the end value of the sampled voltage within the preset diagnosis time does not satisfy a second preset condition, determine that the relay to be tested is in a non-sticking state.

[0130] In an embodiment of the present application, when the voltage difference across the two ends of the relay to be tested satisfies the first preset relationship, that is, |V1-V2| is less than the first voltage threshold and lasts for a first preset time, if the absolute value of the voltage difference between the initial value and the end value of the sampled voltage within the preset diagnostic time satisfies the second preset relationship, that is, |V2final-V2init| is less than the second voltage threshold, then it can be determined that the relay to be tested is in a sticking state; otherwise, if the absolute value of the voltage difference between the initial value and the end value of the sampled voltage within the preset diagnostic time does not satisfy the second preset relationship, that is, |V2final-V2init| is greater than the second voltage threshold, then it can be determined that the relay to be tested is in a non-sticking state.

[0131] Thus, in an embodiment of the present application, when it is detected that the voltage difference across the two ends of the relay to be tested satisfies the first preset condition (i.e., the voltage difference across the two ends of the relay to be tested 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 initial value and the end value of the sampling voltage corresponding to the start time and the end time of the preset diagnosis time are obtained, and then it is determined whether the absolute value of the voltage difference between the initial value and the end value of the sampling voltage satisfies the second preset condition (i.e., whether the absolute value of the voltage difference between the initial value and the end value of the sampling voltage is less than the second voltage threshold); if the initial value and the end value of the sampling voltage satisfy the second preset condition, 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.

[0132] In yet another possible implementation, the preset diagnosis time may include N detection times. 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:

[0133] S801, acquiring an initial value of a sampled voltage collected at a start time of an i-th detection time, and an end value of a sampled voltage collected at an end time of an i-th detection time.

[0134] 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, whether the relay to be tested is stuck is determined based on the collected initial value V2init and final value V2final of the sampled voltage, that is, based on the absolute value of the voltage difference between the initial value and the final value of the sampled voltage |V2final-V2init|.

[0135] S802: Determine whether the absolute value of the voltage difference between the initial value and the end value of the sampling voltage corresponding to the i-th detection time is less than a second voltage threshold.

[0136] S803, determining that the relay to be tested is in a non-sticky state.

[0137] S804, i=i+1.

[0138] S805, when the absolute value of the voltage difference between the initial value and the end value of the sampled voltage 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.

[0139] In this magical embodiment, for step S802, if the judgment result is no, that is, |V2final-V2init| corresponding to the i-th detection time is greater than the second voltage threshold, then step S803 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, |V2final-V2init| corresponding to the i-th detection time is less than the second voltage threshold, then step S804 can be executed, that is, i is executed to add one, and return to step S802 to determine whether |V2final-V2init| corresponding to the next detection time is less than the second voltage threshold. Until i is equal to N, if |V2final-V2init| is less than the second voltage threshold in N detection times, it can be determined that the relay to be tested is in a sticky state.

[0140] In addition, in the embodiment of the present application, if |V2final-V2init| is less than Vth2, then it can be determined that the relay to be tested is in a sticking state; if |V2final-V2init| is greater than Vth2, then it can be determined that the relay to be tested is in a non-sticking state. In addition, for the case where |V2final-V2init| is equal to Vth2, then it can be determined that the relay to be tested is in a sticking state, or it can also be determined that the relay to be tested is in a non-sticking state, and no limitation is made here.

[0141] In this way, still taking the i-th detection time as an example, it can be determined by first determining whether the absolute value of the voltage difference between the end value and the initial value of the sampling voltage within the detection time satisfies the second preset relationship (that is, whether the absolute value of the voltage difference between the end value and the initial value of the sampling voltage within the detection time is less than the second voltage threshold); in this way, when the absolute value of the voltage difference between the end value and the initial value of the sampling voltage within the detection time is greater than the second voltage threshold, 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 voltage difference between the end value and the initial value of the sampling voltage within the current detection time is greater than the second voltage threshold, 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.

[0142] 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 a first sampled voltage collected within a preset diagnosis time is outside a preset voltage range and lasts for a second preset time.

[0143] In the embodiment of the present application, the first sampled voltage may represent the voltage across the series branch consisting of the battery pack and the relay to be tested collected at a certain moment within the preset diagnostic time. The preset voltage range may be related to the battery voltage V1, for example, the preset voltage may be represented by [(100-x)%*V1, (100+x)%*V1], then if the sampled voltage collected within the preset diagnostic time is not within the 100±x% interval and lasts for a second preset time, it is considered that the relay is in a non-adhesive state.

[0144] 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.

[0145] That is to say, in the embodiment of the present application, for the sampled voltage collected, if the sampled voltage collected at the preset diagnostic time is not within the preset voltage range and continues for a 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's sticking diagnosis process can be exited, thereby shortening the diagnosis time and avoiding the problem of misjudgment of sticking.

[0146] 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:

[0147] (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.

[0148] (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. A certain margin time is reserved on the basis of the minimum sampling time to ensure that the sampling voltage drop within T time is greater than Vth). There are multiple fast detection times (i.e., detection time) within the preset diagnostic time. Here, each fast detection time can be 0.1T. If the sampling voltage drop within a certain fast detection time is greater than ±Vth or the sampling voltage drop within the preset diagnostic time is greater than Vth, then it can be considered that the relay to be tested is not sticking. If the non-sticking condition is met, the relay sticking diagnosis can be exited immediately. Otherwise, the relay to be tested is in a sticking state.

[0149] by Figure 1 For example, for Figure 1The 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 .

[0150] In yet another embodiment of the present application, based on the relay adhesion diagnosis method of the above embodiment, combined with 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.

[0151] In the embodiments of the present application, Fig. 9 A timing diagram of a relay adhesion diagnosis to be tested provided in an embodiment of the present application. Fig. 9 As 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 acquisition 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 represents that the response time t11 of the second acquisition 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. 9 As shown, a quick check time may be the diagnosis time t12 between time T0.1 and time T0.2.

[0152] It should be noted that, continue to refer to Fig. 9, 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 acquisition 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. 9 As shown, a quick check time may be the diagnosis time t22 between time T1.1 and time T1.2.

[0153] It should 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, the quick detection time can be 150ms each time, and the response time of the acquisition branch can be 20ms.

[0154] 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.

[0155] In the embodiment of the present application, the diagnosis process of the main positive relay K2 and the main negative relay K3 is the same, and here, the adhesion diagnosis of the main positive relay K2 is used for explanation.

[0156] Judgment condition 1: During the diagnosis time between time T0 and time T1, if |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.

[0157] In the embodiment of the present application, the first preset time may be 700 ms, but is not limited thereto.

[0158] Here, if during the diagnosis time between T0 and T1, if |U1-U2|<5%*U1 does not exist and lasts for the first preset time, it is judged that the main positive relay K2 is in a non-sticky state, that is, the main positive relay K2 is normal. At this time, the adhesion diagnosis of the main positive relay K2 can be ended in advance.

[0159] Judgment condition 2 (adaptive fast detection): During the diagnosis time between T0 and T1, if any of the following conditions is met, the program will jump directly to T1, thus ending the adhesion diagnosis of the main positive relay K2.

[0160] Determination condition 2.1: If U2 is within the preset voltage range and lasts for the second preset time, it is determined that the main positive relay K2 is in a sticking state.

[0161] In the embodiment of the present application, that is, when |U1-U2|<5%*U1 lasts for 150ms, it is considered that the main positive relay K2 is stuck, the preset voltage range can be [95%*U1, 105%*U1], and the second preset time can be 150 milliseconds, but no limitation is made here.

[0162] That is to say, when |U1-U2|<5%*U1 lasts for 150ms, it is considered that the main negative relay is stuck.

[0163] In the embodiment of the present application, Figure 1 For example, when the positive relay K2 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.10 As shown, the horizontal axis represents time, and the vertical axis represents the voltage value of the sampling voltage U2. Among them, 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 positive relay K2 is adhered. Fig.10 In the case of a large Y capacitor in the battery pack, the voltage drops slowly. At this time, when the sampling voltage U2 is at [95%*U1, 105%*U1] and lasts for 60ms, it is easy to falsely report that the relay is sticking. Here, when the relay 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 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 sampled voltage U2 is outside [95%*U1, 105%*U1] and lasts for the second preset time.

[0164] Judgment condition 2.2: 20ms after closing the sampling switch of the main positive relay K2, within the diagnostic time between time Ta and time T1, if the voltage difference between the maximum and minimum values ​​corresponding to U2 is less than 10V (i.e.: U2max-U2min<10V), then it is judged that the main positive relay K2 is in a sticking state.

[0165] Here, the maximum and minimum values ​​corresponding to U2 need to be greater than 50% of the battery pack voltage. At this time, the voltage data collected by the main positive relay K2 needs to be confirmed to be normal.

[0166] It should be noted that, during the diagnosis time between T0.1 and T0.2, if U2max-U2min>10V exists, it is determined that the main positive relay K2 is in a non-adhesive state. If U2max-U2min<10V, then at the next detection time, it is determined whether the voltage difference between the maximum value and the minimum value corresponding to U2 is greater than 10V. Similarly, if the voltage difference between the maximum value and the minimum value of U2 corresponding to each detection time is less than 10V, then it is determined whether the voltage difference between the maximum value and the minimum value of U2 within the preset diagnosis time is less than 10V to further determine whether the main positive relay K2 is in a sticky state.

[0167] In a possible implementation, the diagnostic strategy of the present application 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.

[0168] The embodiment of the present application provides a relay adhesion diagnosis method. The above embodiment describes the specific implementation of the above embodiment in detail, from which it can be seen that the double judgment can also improve the robustness of the relay adhesion diagnosis, avoid the problem of misjudgment of adhesion, and thus improve the reliability of the circuit.

[0169] Based on the same inventive concept as the above embodiments, Fig.11 A schematic diagram of the structure of a relay adhesion diagnosis device provided in an embodiment of the present application. Fig.11 As shown, the relay adhesion diagnosis device 110 may include a collection branch 1101 and a diagnosis branch 1102. The relay adhesion diagnosis device 110 is applied to a circuit to be detected, the circuit to be detected at least includes a series branch consisting of a battery pack and a relay to be detected, and the equivalent capacitance of the circuit to be detected is greater than a preset capacitance;

[0170] The acquisition branch 1101 is connected to the circuit to be detected, and is used to acquire the voltage difference between the two ends of the relay to be tested, and to acquire the sampling voltage corresponding to the series branch within a preset diagnosis time;

[0171] The diagnostic branch 1102 is connected to the acquisition branch 1101, and is used to obtain two sampled voltages corresponding to the series branch collected within a preset diagnostic time when the voltage difference meets a first preset condition; and when the absolute value of the voltage difference between the two sampled voltages within the preset diagnostic time meets a second preset condition, determine that the relay to be tested is in a sticking state.

[0172] In some embodiments, Fig.11 As shown, the acquisition branch 1101 may include a first acquisition branch a1 and a second acquisition branch a2; wherein the first acquisition branch a1 is used to acquire the battery voltage of the battery pack, and the second acquisition branch a2 is used to acquire the sampling voltage corresponding to the two ends of the series branch.

[0173] In some embodiments, the two sampled voltages include: a maximum value and a minimum value of the sampled voltages collected within a preset diagnosis time.

[0174] In some embodiments, the preset diagnostic time includes N detection times; the diagnostic branch 1102 is also used to obtain the maximum and minimum values ​​of the sampled voltage collected within the i-th detection time; when the absolute value of the voltage difference between the maximum and minimum values ​​of the sampled voltage within the i-th detection time does not meet the second preset condition, it is determined 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.

[0175] In some embodiments, the diagnostic branch 1102 is also used to perform an i plus one operation when the absolute value of the voltage difference between the maximum value and the minimum value of the sampling voltage within the i-th detection time satisfies a second preset relationship, until the absolute values ​​of the voltage difference between the maximum value and the minimum value of the sampling voltage within N detection times all satisfy the preset relationship, thereby determining that the relay to be tested is in a sticking state.

[0176] In some implementations, the two sampled voltages include: an initial value of the sampled voltage collected at a start time of a preset diagnosis time and an end value of the sampled voltage collected at an end time of the preset diagnosis time.

[0177] In some embodiments, the preset diagnostic time includes N detection times; the diagnostic module 1103 is also used to obtain the initial value of the sampled voltage collected at the start time of the i-th detection time, and the end value of the sampled voltage collected at the end time of the i-th detection time; when the absolute value of the voltage difference between the initial value and the end value of the sampled voltage in the i-th detection time does not satisfy the second preset relationship, it is determined that the relay to be tested is in a non-sticky state; when the absolute value of the voltage difference between the initial value and the end value of the sampled voltage in the i-th detection time satisfies the second preset relationship, an i plus one operation is performed until the absolute value of the voltage difference between the initial value and the end value of the second voltage in N detection times all satisfy the second preset relationship, and it is determined that the relay to be tested is in a 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.

[0178] In some embodiments, the first preset condition is used to indicate that the voltage difference across the relay to be tested is less than a first voltage threshold and lasts for a first preset time, and the second preset condition is used to indicate that the absolute value of the voltage difference between the two sampled voltages is less than a second voltage threshold.

[0179] In some embodiments, the diagnostic branch 1102 is further used to determine that the relay to be tested is in a non-sticking state when the absolute value of the voltage difference between the maximum value and the minimum value of the sampled voltage within the preset diagnostic time does not satisfy a second preset relationship.

[0180] In some embodiments, the diagnostic branch 1102 is further used to determine that the relay to be tested is in a non-sticking state when the first sampled voltage collected within the preset diagnostic time is outside the preset voltage range and lasts for a second preset time.

[0181] It should be noted that those skilled in the art should understand that the relevant description of the relay adhesion diagnosis device 110 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.

[0182] 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 acquisition branch 1101 may include a first acquisition branch a1 and a second acquisition branch a2, and the second acquisition branch a2 may include a second-first acquisition branch and a second-second acquisition branch, wherein the second-first acquisition branch is used to acquire the sampled voltage U3 at both ends of the series branch formed by the main negative relay K3 and the battery pack B1, and the second-second acquisition branch is used to acquire the sampled voltage U2 at both ends of the series branch formed by the main positive relay K2 and the battery pack B1.

[0183] The embodiment of the present application provides a relay adhesion diagnosis device, which may specifically include an acquisition branch and a diagnostic branch. In this way, the acquisition branch is connected to the circuit to be detected, and the acquisition branch can be used to collect the voltage difference between the two ends of the relay to be tested, as well as the sampled voltage corresponding to the series branch within the preset diagnostic time; the diagnostic branch is connected to the acquisition branch, and the diagnostic branch first makes a preliminary judgment based on whether the voltage difference between the two ends of the relay to be tested meets the first preset condition, and then makes a further judgment based on whether the absolute value of the voltage difference between the two sampled voltages collected within the preset diagnostic time meets the second preset condition. In this way, since the equivalent capacitance of the circuit to be detected is greater than the preset capacitance (for example, several hundred nanofarads), the sampled voltage at the rear end of the relay to be tested drops relatively slowly, and when judging whether the voltage difference meets the first preset condition, it is easy to misjudge the relay adhesion; therefore, after collecting the voltage difference of the relay to be tested, the diagnostic branch will make a preliminary judgment based on whether the voltage difference between the two ends of the relay to be tested meets the first preset condition. After determining the voltage difference between the two ends, a preliminary judgment is first made based on whether the voltage difference satisfies a first preset condition. If the voltage difference satisfies the first preset condition, a further judgment is then made based on whether the absolute value of the voltage difference between the two sampled voltages corresponding to the series branch collected within the preset diagnostic time satisfies a second preset condition. If the voltage drop between the two sampled voltages within the preset diagnostic time satisfies the second preset condition, it can be determined that the relay to be tested is in a sticking state, thereby avoiding the problem of misjudgment of relay sticking due to excessive equivalent capacitance of the circuit to be tested, improving the accuracy of relay sticking diagnosis, and being able to take remedial measures in time when a relay sticking fault is detected. Moreover, the double judgment can also improve the robustness of the relay sticking diagnosis, thereby improving the circuit reliability.

[0184] In yet another embodiment of the present application, Fig.12 A schematic diagram of the structure of a relay adhesion diagnosis system provided in an embodiment of the present application. Fig.12 As shown, the relay sticking diagnosis system 120 may include a circuit to be detected 40 and a relay sticking diagnosis device 110 according to any one of the above embodiments.

[0185] In an embodiment of the present application, the circuit to be tested 40 is composed of a battery pack and a relay to be tested, and the battery pack and the relay to be tested are respectively connected to a relay adhesion diagnosis device 110, which is used to execute a relay adhesion diagnosis method as described in any one of the above embodiments.

[0186] The embodiment of the present application provides a relay adhesion diagnosis system. Since the relay adhesion diagnosis system includes a relay adhesion diagnosis device, after the acquisition branch acquires the voltage difference between the two ends of the relay to be tested and acquires the sampled voltage corresponding to the series branch within the preset diagnosis time, the diagnosis branch first makes a preliminary judgment based on whether the voltage difference between the two ends of the relay to be tested meets a first preset condition, and then makes a further judgment based on whether the absolute value of the voltage difference between the two sampled voltages acquired within the preset diagnosis time meets a second preset condition. In this way, since the equivalent capacitance of the circuit to be detected is greater than the preset capacitance (for example, several hundred nanofarads), the sampled voltage at the rear end of the relay to be tested drops relatively slowly, and the phenomenon of relay adhesion misjudgment is prone to occur when judging whether the voltage difference meets the first preset condition. Therefore, when the voltage difference of the relay to be tested is acquired, the voltage difference between the two sampled voltages acquired within the preset diagnosis time is further judged. After measuring the voltage difference across the relay, a preliminary judgment is first made based on whether the voltage difference satisfies a first preset condition. When the voltage difference satisfies the first preset condition, a further judgment is made based on whether the absolute value of the voltage difference between the two sampled voltages corresponding to the series branch collected within the preset diagnostic time satisfies a second preset condition. If the voltage drop between the two sampled voltages within the preset diagnostic time satisfies the second preset condition, it can be determined that the relay to be tested is in a sticking state, thereby avoiding the problem of misjudgment of relay sticking due to excessive equivalent capacitance of the circuit to be detected, improving the accuracy of relay sticking diagnosis, and being able to take remedial measures in time when a relay sticking fault is detected. Moreover, the double judgment can also improve the robustness of relay sticking diagnosis, thereby improving circuit reliability.

[0187] In yet another embodiment of the present application, the embodiment of the present application provides a computer-readable storage medium, which stores a computer program. When the computer program is executed by at least one processor, the relay adhesion diagnosis method described in any one of the aforementioned embodiments is implemented.

[0188] 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 by a processor, implements the relay adhesion diagnosis method as described in any one of the aforementioned embodiments.

[0189] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, devices, equipment, 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-usable storage media (including but not limited to disk storage and optical storage, etc.) containing computer-usable program codes.

[0190] 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.

[0191] These computer program instructions may also be stored in a computer readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture including an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0192] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0193] It should 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, product 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, product or device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the existence of other identical elements in the process, method, product or device including the element.

[0194] 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.

[0195] The methods disclosed in several method embodiments provided in this application can be arbitrarily combined without conflict to obtain new method embodiments.

[0196] The features disclosed in several product embodiments provided in this application can be arbitrarily combined without conflict to obtain new product embodiments.

[0197] 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.

[0198] 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 detected, the circuit to be detected at least includes a series branch consisting of a battery pack and a relay to be detected, and the equivalent capacitance of the circuit to be detected is greater than a preset capacitance; the relay adhesion diagnosis method includes: Collecting the voltage difference between the two ends of the relay to be tested; When the voltage difference satisfies a first preset condition, obtaining two sampled voltages corresponding to the series branch collected within a preset diagnosis time; When the absolute value of the voltage difference between the two sampled voltages within the preset diagnosis time satisfies a second preset condition, determining that the relay to be tested is in a sticking state; Wherein, the preset diagnosis time includes N detection times; and the relay adhesion diagnosis method further includes: Obtaining two sampled voltages corresponding to the series branch collected within the i-th detection time; When the absolute value of the voltage difference between the two sampled voltages does not satisfy a second preset condition within the i-th detection time, determining that the relay to be tested is in a non-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.

2. The relay adhesion diagnosis method according to claim 1, characterized in that: The two sampled voltages include: a maximum value and a minimum value of the sampled voltages collected within the preset diagnosis time.

3. The relay adhesion diagnosis method according to claim 2, characterized in that: The relay adhesion diagnosis method further includes: Obtaining the maximum and minimum values ​​of the sampled voltage collected within the i-th detection time; When the absolute value of the voltage difference between the maximum value and the minimum value of the sampling voltage within the i-th detection time does not satisfy the second preset condition, it is determined that the relay to be tested is in a non-sticking state.

4. The relay adhesion diagnosis method according to claim 3, characterized in that: The relay adhesion diagnosis method further includes: When the absolute value of the voltage difference between the maximum value and the minimum value of the sampling voltage within the i-th detection time satisfies the second preset condition, an i plus one operation is performed until the absolute values ​​of the voltage difference between the maximum value and the minimum value of the sampling voltage within the N detection times all meet the second preset condition, and it is determined that the relay to be tested is in a sticking state.

5. The relay adhesion diagnosis method according to claim 1, characterized in that: The two sampled voltages include: an initial value of the sampled voltage collected at the start time of the preset diagnosis time and an end value of the sampled voltage collected at the end time of the preset diagnosis time.

6. The relay adhesion diagnosis method according to claim 5, characterized in that: The relay adhesion diagnosis method further includes: Acquire an initial value of the sampled voltage collected at a start time of the i-th detection time, and an end value of the sampled voltage collected at an end time of the i-th detection time; When the absolute value of the voltage difference between the initial value and the end value of the sampling voltage within the i-th detection time does not satisfy the second preset condition, determining that the relay to be tested is in a non-adhesion state; When the absolute value of the voltage difference between the initial value and the end value of the sampling voltage within the i-th detection time satisfies the second preset condition, an i plus one operation is performed until the absolute values ​​of the voltage difference between the initial value and the end value of the sampling voltage within the N detection times all meet the second preset condition, and it is determined that the relay to be tested is in a sticking state.

7. The relay adhesion diagnosis method according to any one of claims 1 to 6, characterized in that: The first preset condition is used to indicate that the voltage difference between the two ends of the relay to be tested is less than a first voltage threshold and lasts for a first preset time; The second preset condition is used to indicate that the absolute value of the voltage difference between the two sampled voltages is less than a second voltage threshold.

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 first sampling voltage collected within the preset diagnosis time 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. 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 absolute value of the voltage difference between the two sampled voltages does not satisfy the second preset condition within the preset diagnosis time, it is determined that the relay to be tested is in a non-sticking state.

10. A relay adhesion diagnosis device, characterized in that: Applied to a circuit to be detected, the circuit to be detected at least includes a series branch consisting of a battery pack and a relay to be detected, and the equivalent capacitance of the circuit to be detected is greater than a preset capacitance; the relay adhesion diagnosis device includes: A collection branch, the collection branch is connected to the circuit to be detected, and is used to collect the voltage difference between the two ends of the relay to be tested, and to collect the sampled voltage corresponding to the series branch within a preset diagnosis time; A diagnostic branch, the diagnostic branch is connected to the acquisition branch, and is used to obtain two sampled voltages corresponding to the series branch acquired within a preset diagnostic time when the voltage difference meets a first preset condition; and determine that the relay to be tested is in a sticking state when the absolute value of the voltage difference between the two sampled voltages within the preset diagnostic time meets a second preset condition; Wherein, the preset diagnosis time includes N detection times; The diagnostic branch is also used to obtain two sampled voltages corresponding to the series branch collected within the i-th detection time; when the absolute value of the voltage difference between the two sampled voltages within the i-th detection time does not meet the second preset condition, it is determined 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.

11. The relay adhesion diagnosis device according to claim 10, characterized in that: The diagnostic branch is also used to obtain the maximum value and the minimum value of the sampled voltage collected within the i-th detection time; when the absolute value of the voltage difference between the maximum value and the minimum value of the sampled voltage within the i-th detection time does not meet the second preset condition, it is determined that the relay to be tested is in a non-sticky 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 9.

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