Relay adhesion detection method and device, battery management system and battery equipment

Abstract

The invention relates to a relay adhesion detection method, a relay adhesion detection device, a battery management system and battery equipment, under the conditions that a relay is triggered to be turned off, a first sampling circuit is controlled to act, and a second sampling circuit is maintained to be turned on, if a sampling voltage is detected to suddenly change along with the action of a switch, it is considered that a second relay is actually turned off. And if it is detected that the sampling voltage does not suddenly change along with the switching action, further combining the sampling voltage and a preset voltage range to determine a detection result whether the second relay is adhered or not. According to the scheme, by controlling the on-off action of the first sampling circuit and maintaining the conduction of the second sampling circuit, the sampling voltage suddenly changes when the second relay is not adhered and jumps out of the preset voltage range. Therefore, the phenomenon that the adhesion of the second relay is misreported due to the fact that the equivalent capacitor of the load connected to the load end of the relay does not completely discharge the voltage and the second sampling circuit obtains the discharge voltage through voltage division can be effectively relieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of battery, in particular to a relay sticking detection method and device, a battery management system and a battery equipment. BACKGROUND

[0002] With the rapid development of new energy technology, secondary batteries represented by lithium batteries are gradually applied to energy storage systems, electric vehicles and aerospace, etc., bringing great convenience to people's daily production and life. The battery management system (BMS) is the core component of monitoring, protecting and managing the battery. The relay in the battery management system is a key executive element, and its reliable on-off is directly related to the safe operation of the load.

[0003] However, in the related art, when detecting the on-off of the relay in the battery management system, the phenomenon of misjudging sticking is prone to occur. SUMMARY

[0004] Therefore, it is necessary to provide a relay sticking detection method and device, a battery management system and a battery equipment to alleviate the phenomenon of misjudging sticking when detecting the on-off of the relay and improve the accuracy of identifying sticking of the relay.

[0005] In a first aspect, the present application provides a relay sticking detection method, which comprises: in the case that a relay is triggered to turn off, controlling a first sampling circuit switch action and maintaining a second sampling circuit conduction; wherein two ends of the first sampling circuit are connected with a first relay and a reference source respectively, two ends of the second sampling circuit are connected with a second relay and the reference source respectively, the first relay is further connected with the reference source through a third sampling circuit, and the second relay is further connected with the reference source; in the case that a voltage change rate of a sampling voltage of the second sampling circuit follows the switch action and exceeds a preset change threshold, determining that the second relay does not occur sticking; and in the case that the voltage change rate of the sampling voltage does not follow the switch action and does not exceed the preset change threshold, determining a sticking detection result of the second relay according to the sampling voltage and a preset voltage range.

[0006] The relay sticking detection method, in the case that the second relay is actually turned off between the reference source and the second sampling circuit, controls the first sampling circuit to operate and maintains the second sampling circuit to be in conduction, which causes the sampling voltage of the second sampling circuit to suddenly change, i.e., the voltage change rate of the sampling voltage exceeds the preset change threshold, so as to jump out of the preset voltage range. Therefore, in the case that the relay is triggered to be turned off and the above control mode is performed, if it is detected that the sampling voltage suddenly changes following the switching action, it is considered that the second relay is actually turned off, i.e., there is no sticking. If it is detected that the sampling voltage does not suddenly change following the switching action, the detection result of whether the second relay is stuck is determined by combining the sampling voltage and the preset voltage range. The above scheme causes the sampling voltage to suddenly change and jump out of the preset voltage range when the second relay is not stuck, which effectively alleviates the phenomenon that the second sampling circuit divides the discharge voltage due to the fact that the equivalent capacitance of the load connected to the load end of the relay is not completely discharged, and improves the accuracy of the sticking identification of the relay.

[0007] In some embodiments, the controlling the switching action of the first sampling circuit and maintaining the second sampling circuit to be in conduction in the case that the relay is triggered to be turned off comprises: obtaining a preliminary result of the relay sticking detection in the case that the relay is triggered to be turned off; and controlling the switching action of the first sampling circuit and maintaining the second sampling circuit to be in conduction in the case that the preliminary result includes the sticking of the second relay.

[0008] The above scheme first performs preliminary sticking diagnosis on the first relay and the second relay in the case that the relay is triggered to be turned off, and controls the switching action of the first sampling circuit and maintains the second sampling circuit to be in conduction in the case that the preliminary result includes the sticking of the second relay, so as to verify the preliminary diagnosis result of the sticking of the second relay, thereby alleviating the misdiagnosis phenomenon in the preliminary sticking diagnosis and improving the accuracy of the sticking diagnosis of the second relay.

[0009] In some embodiments, the controlling the switching action of the first sampling circuit comprises: controlling the switch of the first sampling circuit to be turned off to disconnect the first sampling circuit.

[0010] The above scheme controls the switch of the first sampling circuit to be turned off to disconnect the first sampling circuit, which realizes the switching action control of the first sampling circuit, changes the current flow direction of the second sampling circuit, and further causes the sampling voltage to suddenly change to negative voltage, thereby having the advantage of high accuracy of the sampling voltage sudden change control.

[0011] In some embodiments, the controlling the switching action of the first sampling circuit comprises: periodically controlling the switch of the first sampling circuit to be turned on and turned off.

[0012] The above scheme, by periodically controlling the on-off of the switch of the first sampling circuit, makes the sampling voltage periodically change in positive and negative pressure, effectively reducing the switching loss of the first sampling circuit while making the sampling voltage change abruptly.

[0013] In some embodiments, the second relay adhesion detection result is determined according to the sampling voltage and the preset voltage range, including: in the case of determining that the preset adhesion condition is met according to the sampling voltage and the preset voltage range, it is determined that the second relay is stuck; in the case of determining that the preset adhesion condition is not met according to the sampling voltage and the preset voltage range, it is determined that the second relay is not stuck.

[0014] The above scheme is configured with a preset adhesion condition for adhesion detection, and the sampling voltage and the preset voltage range are analyzed to determine whether the preset adhesion condition is met, thereby realizing the adhesion diagnosis of the second relay, which has the advantages of high diagnosis efficiency and accurate diagnosis result.

[0015] In some embodiments, the method further comprises: in the case where the first duration of the sampling voltage being in the preset voltage range reaches a first preset duration, it is determined that the preset adhesion condition is met.

[0016] The above scheme uses the first preset duration of the sampling voltage being in the preset voltage range as the preset adhesion condition to analyze whether the relay is stuck, which has a high adhesion judgment efficiency.

[0017] In some embodiments, the method further comprises: obtaining a first ground voltage of a first insulation detection circuit and a second ground voltage of a second insulation detection circuit; wherein the first insulation detection circuit is connected to the first relay and the third sampling circuit, and the second insulation detection circuit is connected to the second relay and the reference source; determining a voltage ratio of the first ground voltage and the second ground voltage; in the case where the first duration of the sampling voltage being in the preset voltage range reaches a first preset duration, and in the preset interval of the first duration, the voltage ratio is less than a preset ratio for a second duration of a second preset duration, it is determined that the preset adhesion condition is met.

[0018] The above scheme further combines the first ground voltage of the first insulation detection circuit arranged between the battery end of the first relay and the battery, and the second ground voltage of the second insulation detection circuit arranged between the battery end of the second relay and the battery, to comprehensively analyze whether the preset adhesion condition is met, which has a very high adhesion judgment accuracy.

[0019] The application also provides a relay sticking detection device, which comprises a switch control component, a following verification component and a sticking detection component.

[0020] The application also provides a battery management system, which comprises a reference source, a first relay, a second relay, a first sampling circuit, a second sampling circuit, a third sampling circuit, a first insulation detection circuit, a second insulation detection circuit and a controller.

[0021] The application also provides a battery device, which comprises a battery and the above-mentioned battery management system.

[0022] The application also provides a computer device, which comprises a memory and a processor, the memory stores a computer program, and the processor implements the steps of the above-mentioned relay sticking detection method when executing the computer program.

[0023] The application also provides a computer readable storage medium, which stores a computer program, and the computer program implements the steps of the above-mentioned relay sticking detection method when being executed by a processor. BRIEF DESCRIPTION OF DRAWINGS

[0024] Various other advantages and benefits will become apparent to those of ordinary skill in the art, upon reading the following detailed description of the preferred embodiment. The accompanying drawings are included to provide a better understanding of the preferred embodiment, and are not intended to restrict the application of the application. Moreover, in the drawings, like reference numerals refer to similar components, and in the accompanying sequences that follow, initial letters are used to distinguish between components. In the drawings:

[0025] Figure 1 A schematic diagram of a BJB structure of a battery management system in some embodiments of the application;

[0026] Figure 2 A schematic diagram of a relay sticking detection method in some embodiments of the application;

[0027] Figure 3 A schematic diagram of a BJB topology equivalent circuit in some embodiments of the application;

[0028] Figure 4 A schematic diagram of a BJB topology equivalent circuit in some other embodiments of the application;

[0029] Figure 5 A schematic diagram of a relay sticking detection method in some other embodiments of the application;

[0030] Figure 6 A schematic diagram of a sticking diagnosis process in some embodiments of the application;

[0031] Figure 7 A schematic diagram of a sampling voltage waveform in some embodiments of the application;

[0032] Figure 8 A schematic diagram of a sampling voltage waveform in some other embodiments of the application;

[0033] Figure 9 A schematic diagram of a relay sticking detection device structure in some embodiments of the application. DETAILED DESCRIPTION

[0034] The embodiments of the technical solution of the application will be described in detail below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the application, and therefore only serve as examples, and cannot limit the protection scope of the application.

[0035] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the application; the terms "include" and "have" and any variations thereof in the specification and claims of the application and the above description of drawings are intended to cover non-exclusive inclusion.

[0036] In the description of the embodiments of the present application, the technical terms "first", "second" and the like are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise explicitly specified and limited.

[0037] Reference to "embodiments" herein means that the specific features, structures or properties described in conjunction with the embodiments can be included in at least one embodiment of the present application. The appearance of this phrase at various places in the specification does not necessarily mean the same embodiment, nor is it an independent or alternative embodiment to other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0038] In the description of the embodiments of the present application, the term "and / or" is only used to describe the association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B, which can represent the three cases of A alone, A and B together, and B alone. In addition, the character " / " herein generally represents an "or" relationship between the associated objects before and after it.

[0039] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two), and similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0040] In the description of the embodiments of the present application, unless otherwise explicitly specified and limited, the technical terms "mounting", "connection", "connection", "fixing" and the like should be understood in a broad sense, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanical connection, or it can be electrical connection; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0041] At present, from the development of market situation, the application of battery is more and more widely. Not only is it applied to energy storage power supply systems such as hydroelectric, thermal, wind and solar power stations, but also is widely used in electric bicycles, electric motorcycles, electric vehicles and other electric vehicles, as well as aerospace and other fields. With the continuous expansion of the application field of battery, the demand of its market is also increasing.

[0042] In some scenarios such as electric vehicles, the voltage platform of the battery is relatively high (for example, 400-volt high-voltage platform, 800-volt high-voltage platform, etc.), and if voltage leakage occurs, it will cause electric shock and other accidents, seriously endangering user safety. In the battery management system, the relay as a key executive element, its reliable on-off is directly related to the high-voltage safety of the whole vehicle, and the sticking of the relay refers to the phenomenon that the contact cannot be normally separated due to arc ablation, mechanical jamming and other reasons, and the sticking of the relay is the main factor of voltage leakage.

[0043] Therefore, at present, in the scenarios such as power-on (high-voltage) and power-off (high-voltage) of the battery management system, the sticking detection of the relay is often needed to maintain the relay in a non-sticking operating state. However, the current relay sticking diagnosis scheme is prone to false positives of sticking.

[0044] In Figure 1 In the BJB (Battery Junction Box, battery junction box) high-voltage sampling architecture of the battery management system shown in the figure, the false-positive-sticking relay is often the second relay K2, that is, the relay arranged between the reference source S and the second sampling circuit 12.

[0045] Taking an electric vehicle as an example, it is found through in-depth research that after the whole vehicle is powered off, the equivalent capacitance (that is, Cx shown in the figure) of the load is not completely discharged (usually there is a residual voltage of 30 volts), and when the battery management system wakes up and is powered on again, the first sampling circuit 11 and the second sampling circuit 12 are closed at the same time for sticking diagnosis, which will make the first sampling circuit 11 and the second sampling circuit 12 respectively divide a part of the residual voltage (for example, if the resistances of the two are consistent, then half of the residual voltage is respectively divided), and the voltage will gradually decrease. Since the second sampling circuit 12 is connected in parallel across the reference source S, even if the second relay K2 is off, the sampling voltage of the second sampling circuit 12 will still be within the preset voltage range (usually near the voltage of the reference source S), and finally after diagnosis and analysis, the diagnosis result of the sticking of the second relay K2 is output, resulting in false positive of the sticking of the second relay K2.

[0046] To alleviate the above phenomenon and reduce the false positive of the sticking of the second relay K2, the sampling voltage of the second sampling circuit 12 can be adjusted so that when the second relay K2 does not stick, the sampling voltage changes abruptly and avoids the voltage range of the preset voltage range of the sticking detection, thereby reducing the possibility of false positive of the sticking and performing sticking diagnosis.

[0047] Based on the above considerations, the application provides a relay sticking detection method. In the case that the second relay is actually turned off between the reference source S and the second sampling circuit, the first sampling circuit is controlled to operate, and the second sampling circuit is maintained in a conduction mode. The voltage change rate of the sampling voltage of the second sampling circuit exceeds the preset change threshold, that is, the sampling voltage changes suddenly, so as to jump out of the preset voltage range. Therefore, in the case that the relay is triggered to be turned off and the above control mode is executed, if it is detected that the sampling voltage changes suddenly following the switching action, it is considered that the second relay is actually turned off, that is, there is no sticking. If it is detected that the sampling voltage does not change suddenly following the switching action, the sampling voltage and the preset voltage range are further combined to determine the detection result of whether the second relay is stuck.

[0048] The above scheme controls the switching action of the first sampling circuit and maintains the conduction of the second sampling circuit, so that the sampling voltage of the second relay changes suddenly when the second relay is not stuck, and jumps out of the preset voltage range. In this way, the phenomenon that the second relay is mistakenly reported to be stuck due to the fact that the equivalent capacitance of the load connected to the load end of the relay is not completely discharged, and the discharge voltage is obtained by the voltage division of the second sampling circuit, can be effectively alleviated, and the sticking recognition accuracy of the relay is improved.

[0049] The relay sticking detection method of the system embodiment of the application is applied to Figure 1 The BJB high-voltage sampling architecture of the battery management system shown in the figure. The BJB high-voltage sampling architecture includes a reference source S, a first relay K1, a second relay K2, a first sampling circuit 11, a second sampling circuit 12, a third sampling circuit 13, a first insulation detection circuit 14, a second insulation detection circuit 15, and a controller (not shown in the figure); the first sampling circuit 11 is arranged between the load end of the first relay K1 and the first pole of the reference source S, that is, the two ends of the first sampling circuit 11 are connected to the load end of the first relay K1 and the first pole of the reference source S, respectively; the second sampling circuit 12 is arranged between the load end of the second relay K2 and the first pole of the reference source S, that is, the two ends of the second sampling circuit 12 are connected to the load end of the second relay K2 and the first pole of the reference source S, respectively.

[0050] The battery end of the first relay K1 is also connected to the first pole of the reference source S through the third sampling circuit 13, the battery end of the second relay K2 is also connected to the second pole of the reference source S, the first end of the first insulation detection circuit 14 is connected to the first pole of the battery and the battery end of the first relay K1, the first end of the second insulation detection circuit 15 is connected to the second pole of the battery and the battery end of the second relay K2, the load end of the first relay K1 and the load end of the second relay K2 are also connected to the load, and the second end of the first insulation detection circuit 14 and the second end of the second insulation detection circuit 15 are grounded; the first relay K1, the second relay K2, the first sampling circuit 11 (through the ADC1 port in the figure), the second sampling circuit 12 (through the ADC2 port in the figure), the third sampling circuit 13 (through the ADC3 port in the figure), the first insulation detection circuit 14 (through the ADC4 port in the figure) and the second insulation detection circuit 15 (through the ADC5 port in the figure) are respectively connected to the controller.

[0051] Further, for the convenience of understanding, in the BJB high-voltage sampling architecture, the remaining devices or circuits between the first insulation detection circuit 14 and the first pole of the battery are equivalent to the resistance Rp1 and the capacitor Cp1; the remaining devices or circuits between the second insulation detection circuit 15 and the second pole of the battery are equivalent to the resistance Rn1 and the capacitor Cn1. The load connected to the BJB architecture is equivalent to the load capacitor Cx and the equivalent impedance Rx, the other devices or circuits between the load end of the first relay K1 and the load are equivalent to the resistance Rp2 and the capacitor Cp2, the other devices or circuits between the load end of the second relay K2 and the load are equivalent to the resistance Rn2 and the capacitor Cn2, and finally the equivalent architecture diagram shown in the figure is obtained. Figure 1 Battery+ in the figure represents the first pole of the battery, Battery- in the figure represents the second pole of the battery, Link+ and Link- are the ports for connecting the load; U2 represents the sampling voltage of the first sampling circuit 11, U7 represents the sampling voltage of the second sampling circuit 12, Up1 represents the first voltage to ground, and Un1 represents the second voltage to ground.

[0052] It can be understood that the battery management system of the present application can be applied to electric vehicles such as electric cars, electric motorcycles, electric bicycles, etc., and can also be applied to energy storage power systems, aerospace, etc., and the specific application is not limited. In order to facilitate the understanding of the technical solutions of the present application, the following will be explained and described by taking the application of the battery management system in electric vehicles as an example.

[0053] It should be noted that the types of the first relay K1 and the second relay K2 are not unique. In one embodiment, the first relay K1 can be a main positive relay, and the second relay K2 can be a main negative relay. In this case, the first pole of the battery is positive, and the second pole of the battery is negative. In this case, the sticking detection of the main negative relay can be implemented. In another embodiment, the first relay K1 can be a main negative relay, and the second relay K2 can be a main positive relay. In this case, the first pole of the battery is negative, and the second pole of the battery is positive. In this case, the sticking detection of the main positive relay can be implemented. In order to facilitate the understanding of the technical solutions of the present application, the following embodiments can be considered that the first relay K1 is a main positive relay, and the second relay K2 is a main negative relay.

[0054] Referring to Figure 2 , in a first aspect, the present application provides a relay sticking detection method, which comprises steps 202, 204 and 206.

[0055] In step 202, in the case that the relay is triggered to be turned off, the first sampling circuit is controlled to be switched and the second sampling circuit is maintained to be turned on.

[0056] Specifically, the BJB structure of the battery management system is as shown in Figure 1 . Details are not described hereinafter. In some embodiments, the first sampling circuit 11 is arranged between the load end of the first relay K1 and the first pole of the reference source S, the second sampling circuit 12 is arranged between the load end of the second relay K2 and the first pole of the reference source S, the battery end of the first relay K1 is further connected to the first pole of the reference source S through the third sampling circuit 13, and the battery end of the second relay K2 is further connected to the second pole of the reference source S.

[0057] The battery end refers to the end of the relay close to the battery in electrical connection, and the load end refers to the end of the relay close to the load in electrical connection. The relay is triggered to be turned off, which means that the relay receives a turn-off instruction from the controller and controls the contact to be disconnected under the action of the turn-off instruction. The sticking of the relay refers to the phenomenon that the contact cannot be normally separated due to arc ablation, mechanical jamming and the like. Therefore, it is usually necessary to perform sticking diagnosis in the case that the relay is triggered to be turned off. The control of the switching of the first sampling circuit 11 refers to the control of the turning on and turning off of the switching device in the first sampling circuit 11, so as to change the access state of the first sampling circuit 11 in the BJB architecture.

[0058] The first sampling circuit 11 is arranged between the load end of the first relay K1 and the first pole of the reference source S, and is used to sample the voltage between the load end of the first relay K1 and the reference source S. The second sampling circuit 12 is arranged between the load end of the second relay K2 and the first pole of the reference source S, and is used to sample the voltage between the load end of the second relay K2 and the reference source S. The third sampling circuit 13 is arranged between the battery end of the first relay K1 and the first pole of the reference source S, and is used to sample the voltage between the battery end of the first relay K1 and the reference source S.

[0059] The reference source S is also called a reference source or a reference voltage source, which is used to provide a stable and accurate voltage output, and is used to calibrate and compare other voltage signals to maintain the stable operation of the BJB architecture. It can be understood that the voltage of the reference source S is not unique, and can be selected according to actual needs. In a more detailed embodiment, the reference source S is a voltage source providing a 5V voltage.

[0060] It should be pointed out that the structures of the first sampling circuit 11, the second sampling circuit 12 and the third sampling circuit 13 are not unique. In an embodiment, the above-mentioned sampling circuits can be built by using a voltage dividing circuit. Specifically, in actual scenarios, the first sampling circuit 11 and the second sampling circuit 12 need to be controlled according to actual needs, so the structures of the first sampling circuit 11 and the second sampling circuit 12 are similar, and each includes two resistors and a switching device connected in series, that is, the first sampling circuit 11 includes a first resistor R1, a first switching device S1 and a second resistor R2 connected in series, and the second sampling circuit 12 includes a third resistor R3, a second switching device S2 and a fourth resistor R4 connected in series. The third sampling circuit 13 needs to maintain a conduction state, so the third sampling circuit 13 does not need to be configured with a switching device, and can include a fifth resistor R5 and a sixth resistor R6 connected in series.

[0061] Therefore, in an embodiment, the controller can control the switching action of the first sampling circuit 11 by controlling the action (that is, the on-off) of the first switching device S1, and can control the second sampling circuit 12 to maintain a conduction state by controlling the conduction of the second switching device S2.

[0062] It can be understood that the types of the above-mentioned first switching device and the second switching device are not unique, and the types of the two can be the same or different. In an embodiment, a transistor, a field effect transistor or an insulated gate bipolar transistor can be used as a switching device, and the specific type is not limited.

[0063] In step 204, if the voltage variation rate of the sampling voltage of the second sampling circuit exceeds the preset variation threshold following the switching action, it is determined that the second relay does not stick.

[0064] Specifically, the equivalent architecture of the BJB can refer to Figure 1 The remaining devices or circuits can be represented in the form of equivalent resistance and equivalent capacitance. The voltage change rate is the change amplitude of the sampling voltage when the first sampling circuit 11 is switched (denoted as the real-time sampling voltage) relative to the sampling voltage when the first sampling circuit 11 is not switched (denoted as the initial sampling voltage). Exceeding the preset change threshold, that is, greater than or equal to the preset change threshold; the preset change threshold is a threshold that the voltage change rate can reach when the second relay K2 is actually turned off. The size of the preset change threshold is not unique, which is not limited here, and can be configured in combination with the actual scene. For example, in an embodiment, the preset change threshold can be configured as 60%, and in another embodiment, it can also be configured to be greater than 60% or less than 60%, which is not limited in detail.

[0065] In more detail, in an embodiment, the absolute value of the difference between the real-time sampling voltage and the initial sampling voltage can be divided by the initial sampling voltage to obtain the voltage change rate.

[0066] It can be understood that in an embodiment, after the first sampling circuit 11 is switched, the sampling voltage of the second sampling circuit 12 is collected in real time, and each time a sampling voltage is collected, it can be calculated with the sampling voltage when the first sampling circuit 11 is not switched to obtain the voltage change rate.

[0067] The first sampling circuit 11 and the second sampling circuit 12 are both turned on, and in the case that the load is not completely discharged, if the resistance values of the first sampling circuit 11 and the second sampling circuit 12 are the same, then the first sampling circuit 11 and the second sampling circuit 12 will respectively divide the voltage of half of the equivalent capacitance of the load, which will easily cause the sampling voltage of the second sampling circuit 12 to be in the preset voltage range, and then the diagnosis result of the second relay K2 sticking is obtained in the sticking diagnosis logic, which is easy to misjudge the sticking.

[0068] The scheme of the present embodiment, if the second relay K2 does not stick, then in the case that the first sampling circuit 11 and the second sampling circuit 12 are both turned on, the current flow direction of the equivalent architecture can refer to Figure 3 At this time, the current flow through the second sampling circuit 12 is shown as I1 in the figure. And in the case that the first sampling circuit 11 is switched to turn off the first sampling circuit 11 while maintaining the second sampling circuit 12 to be turned on, the current flow direction will be changed to Figure 4The I2 direction shown will cause the sampling voltage of the second sampling circuit 12 to change abruptly, and no longer be within the preset voltage range, reducing the possibility of false adhesion. If the second relay K2 is stuck at this time, there will be a second sampling circuit 12-second relay K2-reference source S second pole line, at this time the above-mentioned voltage abrupt change phenomenon (i.e. the voltage change rate of the sampling voltage exceeds the preset change threshold) will not occur.

[0069] Therefore, after the controller controls the switching action of the first sampling circuit 11 and maintains the conduction of the second sampling circuit 12, it needs to receive the sampling voltage collected by the second sampling circuit 12 in real time to determine whether the voltage changes abruptly, and obtain the adhesion diagnosis result of the second relay K2.

[0070] Step 206, in the case that the voltage change rate of the sampling voltage does not exceed the preset change threshold following the switching action, the adhesion detection result of the second relay is determined according to the sampling voltage and the preset voltage range.

[0071] Specifically, the preset voltage range refers to the voltage threshold range that can be reached between the load end of the second relay K2 and the first pole of the reference source S in the case that the second relay K2 is stuck. When the sampling voltage changes abruptly following the switching action, the controller will directly determine that the second relay K2 is not stuck, and in the case that the sampling voltage does not change abruptly following the switching action, the final adhesion detection result needs to be output in combination with the current state of the sampling voltage and the preset voltage range.

[0072] The above-mentioned relay adhesion detection method, in the case that the second relay K2 is truly turned off between the reference source S and the second sampling circuit 12, controls the action of the first sampling circuit 11 to maintain the conduction of the second sampling circuit 12, which will cause the sampling voltage of the second sampling circuit 12 to change abruptly and thus jump out of the preset voltage range. Therefore, in the case that the relay is triggered to turn off and the above-mentioned control method is executed, if it is detected that the sampling voltage changes abruptly following the switching action, it is considered that the second relay K2 is truly turned off, i.e. there is no adhesion. If it is detected that the sampling voltage does not change abruptly following the switching action, the detection result of whether the second relay K2 is stuck is determined in combination with the sampling voltage and the preset voltage range. The above-mentioned scheme controls the switching action of the first sampling circuit 11 and maintains the conduction of the second sampling circuit 12, which causes the sampling voltage of the second relay K2 to change abruptly when the second relay K2 is not stuck and thus jumps out of the preset voltage range. In this way, the phenomenon that the second sampling circuit 12 divides the discharged voltage due to the fact that the equivalent capacitance of the load connected to the load end of the relay is not completely discharged, and thus falsely reports that the second relay K2 is stuck, can be effectively alleviated, and the adhesion recognition accuracy of the relay is improved.

[0073] Please refer to Figure 5 In some embodiments, step 202 comprises step 502 and step 504.

[0074] Step 502, in the case of relay triggering off, obtaining the preliminary result of the relay sticking detection.

[0075] Step 504, in the case of the preliminary result including the second relay sticking, controlling the switching action of the first sampling circuit and maintaining the second sampling circuit conduction.

[0076] Specifically, the scheme of the present embodiment, in the case of relay triggering off, can first perform preliminary diagnosis on the first relay K1 and the second relay K2 respectively. Since in actual scenarios, the misjudgment of sticking often occurs in the second relay K2, the preliminary detection result of the first relay K1 sticking can be directly used as the sticking detection result of the first relay K1.

[0077] As for the second relay K2, since it is arranged between the second sampling circuit 12 and the reference source S, in the case of sticking, the second sampling circuit 12 is arranged in parallel between the first pole and the second pole of the reference source S, and the sampling voltage thereof will be the same or substantially the same as the voltage of the reference source S. If there is residual voltage in the equivalent capacitance of the load during the preliminary diagnosis process, and the voltage obtained by the second sampling circuit 12 is also the same or substantially the same as the voltage of the reference source S, even if the second relay K2 does not stick, at this time, it will be considered that this kind of voltage state is caused by the sticking of the second relay K2, that is, the misreporting of sticking occurs.

[0078] Therefore, after the preliminary sticking diagnosis of the first relay K1 and the second relay K2 is performed, and the preliminary result of the second relay K2 sticking is obtained, the second relay K2 cannot be directly determined to stick. Instead, the scheme of the present embodiment is combined to control the switching action of the first sampling circuit 11 and maintain the conduction of the second sampling circuit 12, and then perform secondary sticking diagnosis on the sampling voltage of the second sampling circuit 12 and the preset voltage range, so as to use the result of the secondary sticking diagnosis as the sticking diagnosis result of the second relay K2.

[0079] The above scheme, in the case of relay triggering off, first performs preliminary sticking diagnosis on the first relay K1 and the second relay K2. If the preliminary result includes the second relay K2 sticking, the action of controlling the switching action of the first sampling circuit 11 and maintaining the conduction of the second sampling circuit 12 will be performed to verify the preliminary diagnosis result of the second relay K2 sticking, thereby relieving the misdiagnosis phenomenon during the preliminary sticking diagnosis and improving the sticking diagnosis detection accuracy of the second relay K2.

[0080] It should be noted that the above-mentioned preliminary sticking diagnosis of the relay is not the only one, and in an embodiment, the first sampling circuit 11 and the second sampling circuit 12 can be controlled to be turned on, and by obtaining the sampling voltage of the first sampling circuit 11 and the sampling voltage of the second sampling circuit 12, and combining the pre-set sticking diagnosis logic respectively to analyze and judge, a preliminary result can be obtained.

[0081] Specifically, in an embodiment, for the first relay K1, whether it sticks can be judged by detecting the size of the sampling voltage. If the first relay K1 sticks, a path will be formed between the first sampling circuit 11 and the third sampling circuit 13 through the first relay K1, at this time, the first sampling circuit 11 and the third sampling circuit 13 are equivalent to be connected in parallel. In the BJB architecture, the sum of the sampling voltage of the third sampling circuit 13 and the voltage of the reference source S is equal to the battery voltage, at this time, the sampling voltage of the first sampling circuit 11 will be relatively large. When the first relay K1 does not stick, even if there is a voltage division of the equivalent capacitance of the load, only a small voltage (such as zero if there is no voltage division) will be sampled at the first sampling circuit 11. Based on this, the sticking detection of the first relay K1 can be realized.

[0082] For the second relay K2, a pre-set voltage range can be set according to the voltage of the reference source S, for example, a 5V reference source S, a pre-set voltage range of 3V-7V can be set (other embodiments can also be set to other sizes, such as 4V-6V, etc.). At this time, if it is detected that the sampling voltage of the second sampling circuit 12 is not in the pre-set voltage range, it is considered that the second relay K2 does not stick; if it is in the pre-set voltage range, it may be that the second relay K2 sticks, or there may be a voltage division of the equivalent capacitance of the load to the second sampling circuit 12.

[0083] In some embodiments, the control of the switching action of the first sampling circuit 11 includes: controlling the switch of the first sampling circuit 11 to be turned off to disconnect the first sampling circuit 11.

[0084] Specifically, in the case of the first sampling circuit 11 being turned off, if the second relay K2 does not stick, it will cause the current of the second sampling circuit 12 to be reversed, and accordingly, the sampling voltage will have a sudden change from positive voltage to negative voltage. The absolute value of the difference between the real-time sampling voltage (negative voltage) and the initial sampling voltage (positive voltage) divided by the initial sampling voltage will obtain a change rate greater than 1, which will be greater than a pre-set change threshold, that is, the sampling voltage has a sudden change. Therefore, the first sampling circuit 11 can be controlled to be in a turned-off state for a long time to detect the sticking of the second relay K2.

[0085] The above scheme, in a manner of controlling the switch of the first sampling circuit 11 to be off so that the first sampling circuit 11 is disconnected, realizes the switch action control of the first sampling circuit 11, changes the current direction of the second sampling circuit 12, and further makes the sampling voltage suddenly change to negative voltage, and has the advantage of high accuracy of sampling voltage sudden change control.

[0086] In some embodiments, the switch action of the first sampling circuit 11 includes: periodically controlling the switch of the first sampling circuit 11 to be on and off.

[0087] Specifically, unlike the sampling voltage of the second sampling circuit 12 being maintained at negative voltage in the above-mentioned embodiments, the scheme of the present embodiment can periodically control the switch of the first sampling circuit 11 to be on and off, that is, in a period, the first sampling circuit 11 performs one off operation and one on operation. In this way, if the second relay K2 does not stick, the sampling voltage of the second sampling circuit 12 will also change periodically, and in this way, the sticking diagnosis of the second relay K2 can also be realized.

[0088] It can be understood that the periodic control of the switch of the first sampling circuit 11 to be on and off is not unique, and in an embodiment, a pulse width modulation signal (PWM) can be used to drive the switch device of the first sampling circuit 11 to operate. In another embodiment, a switch-off trigger pulse can be sent to the switch device of the first sampling circuit 11 every certain time interval to make it periodically off.

[0089] The above scheme, by periodically controlling the switch of the first sampling circuit 11 to be on and off, makes the sampling voltage change periodically between positive voltage and negative voltage, effectively reducing the switching loss of the first sampling circuit while making the sampling voltage change suddenly.

[0090] In some embodiments, the sticking detection result of the second relay is determined according to the sampling voltage and the preset voltage range, including: in a case where it is determined that the preset sticking condition is met according to the sampling voltage and the preset voltage range, it is determined that the second relay sticks; and in a case where it is determined that the preset sticking condition is not met according to the sampling voltage and the preset voltage range, it is determined that the second relay does not stick.

[0091] Specifically, the preset sticking condition refers to a condition that needs to be met between the sampling voltage of the second sampling circuit 12 and the preset voltage range in a case where the second relay K2 sticks. The controller pre-stores the preset sticking condition, and after the switch action of the first sampling circuit 11 is controlled to obtain the sampling voltage of the second sampling circuit 12, the sampling voltage is compared and analyzed with the preset voltage range to determine whether the preset sticking condition is met, so as to determine whether the second relay K2 sticks according to the determination result.

[0092] The scheme has the advantages that the preset adhesion condition is configured for adhesion detection, the preset adhesion condition is analyzed in combination with the sampling voltage and the preset voltage range, the adhesion diagnosis of the second relay K2 is realized, and the diagnosis efficiency is high and the diagnosis result is accurate.

[0093] In some embodiments, the method further includes: in a case where the sampling voltage is in the preset voltage range for a first duration that reaches a first preset duration, determining that the preset adhesion condition is met.

[0094] Specifically, the preset voltage range is determined according to the voltage of the reference source S, and the size of the preset voltage range is not unique. As long as the adhesion range contains the voltage of the reference source S, the upper limit value is greater than the voltage of the reference source S, and the lower limit value is less than the voltage of the reference source S. For example, in one embodiment, the preset voltage range can be set to 3V-7V as in the above embodiment; in another embodiment, it can also be 4V-6V, 3.5V-6.5V, etc., and the specific value is not limited.

[0095] The first duration is the duration that the sampling voltage is in the preset voltage range. The size of the first preset duration is not unique, and can be configured in combination with the actual scene and demand. For example, in one embodiment, the first preset duration can be set to 1000ms (milliseconds), and in another embodiment, it can also be configured to other sizes, such as any value within 500ms-1500ms, and the specific value is not limited.

[0096] The controller obtains the sampling voltage of the second sampling circuit 12 and compares it with the preset voltage range. If the sampling voltage is in the preset voltage range, timing starts. If the sampling voltage still maintains in the preset voltage range when the timing reaches the first preset duration, it is considered that the preset adhesion condition is met at this time.

[0097] The above scheme uses the duration that the sampling voltage is in the preset voltage range to reach the first preset duration as the preset adhesion condition to analyze whether the relay is stuck, and has high adhesion judgment efficiency.

[0098] Further, in another embodiment, it is considered that the preset adhesion condition is met when it is detected that the sampling voltage is in the preset voltage range, and the specific value is not limited.

[0099] Please refer to Figure 6 In some embodiments, the method further includes steps 602, 604 and 606.

[0100] Step 602: obtaining a first ground voltage of a first insulation detection circuit and a second ground voltage of a second insulation detection circuit.

[0101] Step 604, determine the voltage ratio of the first ground voltage and the second ground voltage.

[0102] Step 606, determine that the preset adhesion condition is met in a case that the sampling voltage is in the preset voltage range for a first duration reaching a first preset duration, and in a preset interval of the first duration, the voltage ratio is less than a preset ratio for a second duration reaching a second preset duration.

[0103] Specifically, the first insulation detection circuit 14 is connected to the battery end of the first relay K1, and the second insulation detection circuit 15 is connected to the battery end of the second relay K2. The first insulation detection circuit 14 is a circuit arranged between the first pole of the battery and the ground, used to detect the insulation performance of the first pole of the battery to the ground; the second insulation detection circuit 15 is a circuit arranged between the second pole of the battery and the ground, used to detect the insulation performance of the second pole of the battery to the ground. The first ground voltage is the voltage between the first insulation detection circuit 14 and the ground; the second ground voltage is the voltage between the second insulation detection circuit 15 and the ground. The second duration refers to the duration that the voltage ratio is less than the preset ratio.

[0104] In actual scenarios, reference can be made to Figure 1 If a unilateral insulation fault occurs in the BJB, a large difference in voltage distribution between the first ground voltage Up1 and the second ground voltage Un1 will occur, resulting in a large proportional difference in the voltage ratio Up1 / Un1. Specifically, if an insulation fault occurs between the second insulation detection circuit 15 and the second pole of the battery, and the resistance Rn1 has a resistance value less than a set value (e.g., 5 kΩ), the second ground voltage Un1 will tend to 0, which will also easily cause the sampling voltage of the second sampling circuit 12 to approach the preset voltage range, thereby causing a false adhesion report.

[0105] Therefore, in the case that the first duration of the sampling voltage in the preset voltage range reaches the first preset duration, the voltage ratio of the first ground voltage and the second ground voltage needs to be further analyzed to consider the influence of unilateral insulation fault on adhesion diagnosis.

[0106] Finally, in a case that the voltage ratio is less than the preset ratio within a certain interval of the first duration of the sampling voltage in the preset voltage range, and the duration of this state reaches the second preset duration, it is considered that the preset adhesion condition is met.

[0107] It can be understood that the setting of the preset interval is not unique, and it can be set in combination with the first preset duration, and any segment in the first preset duration is selected as the preset interval. For example, in an embodiment, the first preset duration is set to 1000 ms, and correspondingly, the interval of 350 ms-500 ms in the first preset duration can be set as the preset interval.

[0108] At the beginning of the preset interval, the voltage ratio is compared with the preset ratio, and if the voltage ratio is less than the preset ratio, the timing is started. Finally, when the timing reaches the second preset time length in the preset interval, and the first continuous time length of the sampling voltage in the preset voltage range also reaches the first preset time length, it is considered that the preset adhesion condition is met.

[0109] It should be pointed out that the size of the preset ratio and the second preset time length is not unique, the second preset time length needs to be set to be less than the length of the set interval, and the preset ratio is determined in combination with the set insulation fault boundary resistance value. For example, in a more detailed embodiment, the set interval is 350ms-500ms, and the length of the set interval is 150ms. The second preset time length can be set to 100ms.

[0110] For reference Figure 1 In an embodiment, the first insulation detection circuit 14 includes a first main switch S01, and a first bridge arm circuit and a first main detection circuit connected in parallel. The structure formed by the first bridge arm circuit and the first main detection circuit is connected in series with the first main switch S01. The second insulation detection circuit 15 includes a second main switch S02, and a second bridge arm circuit and a second main detection circuit connected in parallel. The structure formed by the second bridge arm circuit and the second main detection circuit is connected in series with the second main switch S02.

[0111] Further, the first main detection circuit includes a resistor R7 and a resistor R8 connected in series, the first bridge arm circuit includes a third switching device S3 and a resistor R9 connected in series, the second main detection circuit includes a resistor R10 and a resistor R11 connected in series, and the second bridge arm circuit includes a fourth switching device S4 and a resistor R12 connected in series. Accordingly, Up1 / Un1=(R7+R8) / ((R10+R11) / / Rn1) can be obtained. In a more detailed embodiment, the insulation fault boundary resistance value is set to 5kΩ, and the preset ratio is calculated by substituting the above formula to obtain 379.

[0112] The above scheme also comprehensively analyzes whether the preset adhesion condition is met by combining the first ground voltage of the first insulation detection circuit 14 arranged between the battery end of the first relay K1 and the battery, and the second ground voltage of the second insulation detection circuit 15 arranged between the battery end of the second relay K2 and the battery, which has extremely high adhesion judgment accuracy.

[0113] In order to facilitate understanding of the technical scheme of the present application, the present application will be explained and described in detail below in combination with more detailed embodiments.

[0114] The BJB architecture of the battery management system is as follows Figure 1As shown, under the condition of high voltage of the whole vehicle, the first relay K1 and the second relay K2 are controlled to be turned off, so that the equivalent impedance of the load discharges the voltage stored in the equivalent capacitor of the load. When the BMS wakes up again to turn on the high voltage, the first sampling circuit 11 and the second sampling circuit 12 are both controlled to be closed, the first insulation detection circuit 14 and the second insulation detection circuit 15 are maintained to be connected to operate, and the first relay K1 and the second relay K2 are preliminarily diagnosed to obtain a preliminary result.

[0115] For reference Figure 7 The abscissa represents time and the ordinate represents voltage. If the second relay K2 does not actually stick, but the residual voltage of the load capacitor is obtained by the voltage division of the second sampling circuit 12, at this time, the sampling voltage is within the preset voltage range, and the sticking is falsely reported. Therefore, in the preliminary result including the sticking of the second relay K2, the controller controls the switching device of the first sampling circuit 11 to be turned off, maintains the second sampling circuit 12 to be turned on, and obtains the sampling voltage of the second sampling circuit 12.

[0116] For reference Figure 8 The abscissa represents time and the ordinate represents voltage. If the second relay K2 does not actually stick, through the above-mentioned action, the sampling voltage will suddenly change to negative voltage. Therefore, if the sampling voltage suddenly changes from positive voltage to negative voltage following the turning-off action of the first sampling circuit 11, the diagnostic result that the second relay K2 does not stick is output (that is, the preliminary result is inaccurate at this time). If the sampling voltage does not suddenly change following the turning-off action of the first sampling circuit 11, the sampling voltage and the preset voltage range are further analyzed.

[0117] If the analysis result is that the sampling voltage is within the preset voltage range of 3V-7V and the first duration reaches 350ms, the controller collects the first voltage to ground and the second voltage to ground, and calculates the voltage ratio. The voltage ratio is compared with the preset ratio (such as 379). If the voltage ratio is less than the preset ratio, the timing starts. Finally, under the condition that the voltage ratio is less than the preset ratio for a second duration reaching a second preset time (such as 100ms) and the first duration reaches a first preset time (such as 1000ms) within the preset interval of 350ms-500ms, it is considered that the second relay K2 sticks. Otherwise, it is considered that the second relay K2 does not stick.

[0118] It can be understood that, in the scheme of the embodiments of the present application, the first insulation detection circuit 14 and the second insulation detection circuit 15 continuously operate in the on state, specifically, the first main switch S01 of the first insulation detection circuit 14 is maintained in the on state, the first bridge arm circuit is maintained in the off state, the second main switch S02 of the second insulation detection circuit 15 is maintained in the on state, and the second bridge arm circuit is maintained in the off state. Moreover, the second sampling circuit 12 also operates in the on state, and when the sticking detection of the second relay K2 is performed, only the switching action of the first sampling circuit 11 needs to be controlled.

[0119] It should be understood that, although each step in the flowchart involved in each of the above-described embodiments is shown in sequence according to the arrow, these steps are not necessarily executed in the order indicated by the arrow. Unless otherwise specified herein, the execution of these steps is not strictly limited in sequence, and these steps can be executed in other orders. Moreover, at least part of the steps in the flowchart involved in each of the above-described embodiments can include multiple steps or stages, which are not necessarily executed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily sequential, but can be alternately or alternately executed with at least part of other steps or steps or stages in other steps. It can be understood that the steps in different embodiments can be freely combined as needed, and various non-contradictory schemes formed by the combination are within the scope of protection of the present application.

[0120] Based on the same inventive concept, the embodiments of the present application also provide a relay sticking detection device for implementing the above-mentioned relay sticking detection method. The implementation scheme for solving the problem provided by the device is similar to the implementation scheme described in the above method, so the specific limitations in one or more relay sticking detection device embodiments provided below can refer to the limitations of the relay sticking detection method in the above text, which will not be repeated here.

[0121] Please refer to Figure 9 The present application also provides a relay sticking detection device, which comprises a switch control component 702, a following verification component 704, and a sticking detection component 706.

[0122] The switch control component 702 is used to control the switching action of the first sampling circuit and maintain the on state of the second sampling circuit when the relay is triggered off. The following verification component 704 is used to determine that the second relay does not stick when the voltage change rate of the sampling voltage of the second sampling circuit and the switching action follow the preset change threshold. The sticking detection component 706 is used to determine the sticking detection result of the second relay according to the sampling voltage and the preset voltage range when the voltage change rate of the sampling voltage and the switching action do not follow the preset change threshold.

[0123] In some embodiments, the switch control component 702 is further configured to obtain a preliminary result of the relay sticking detection in the case that the relay is triggered to turn off, and control the first sampling circuit switch to turn off and maintain the second sampling circuit to turn on in the case that the preliminary result includes the second relay sticking.

[0124] In some embodiments, the switch control component 702 is further configured to control the first sampling circuit switch to turn off to disconnect the first sampling circuit.

[0125] In some embodiments, the switch control component 702 is further configured to periodically control the first sampling circuit switch to turn on and turn off.

[0126] In some embodiments, the sticking detection component 706 is further configured to determine that the second relay sticks in the case that the preset sticking condition is met according to the sampling voltage and the preset voltage range, and determine that the second relay does not stick in the case that the preset sticking condition is not met according to the sampling voltage and the preset voltage range.

[0127] In some embodiments, the sticking detection component 706 is further configured to determine that the preset sticking condition is met in the case that the first duration of the sampling voltage being in the preset voltage range reaches the first preset time length.

[0128] In some embodiments, the sticking detection component 706 is further configured to obtain a first ground voltage of the first insulation detection circuit and a second ground voltage of the second insulation detection circuit, determine a voltage ratio of the first ground voltage and the second ground voltage, and determine that the preset sticking condition is met in the case that the first duration of the sampling voltage being in the preset voltage range reaches the first preset time length, and the voltage ratio is less than a preset ratio for a second preset time length in a preset interval of the first duration.

[0129] The above components of the relay sticking detection apparatus can be all or partially implemented by software, hardware, and combinations thereof. The above components can be embedded in or independent of a processor in a computer device in hardware form, or stored in a memory in the computer device in software form, so as to be called and executed by a processor to perform the operations corresponding to the above components.

[0130] The relay sticking detection device, in the case of the second relay K2 being actually turned off between the reference source S and the second sampling circuit 12, by controlling the first sampling circuit 11 to act, the second sampling circuit 12 is maintained in the on state, so that the sampling voltage of the second sampling circuit 12 is suddenly changed, so as to jump out of the preset voltage range. Therefore, in the case of the relay being triggered to turn off and the above-mentioned control mode being executed, if it is detected that the sampling voltage suddenly changes following the switching action, it is considered that the second relay K2 is actually turned off, that is, there is no sticking. If it is detected that the sampling voltage does not suddenly change following the switching action, the detection result of whether the second relay K2 is stuck is determined by further combining the sampling voltage and the preset voltage range. The above-mentioned scheme, by controlling the switching action of the first sampling circuit 11 and maintaining the on state of the second sampling circuit 12, makes the sampling voltage of the second relay K2 suddenly change when the second relay K2 is not stuck, and jumps out of the preset voltage range. In this way, the phenomenon that the second relay K2 is stuck due to the fact that the equivalent capacitance of the load connected to the load end of the relay is not completely discharged voltage, so that the second sampling circuit 12 divides the discharged voltage, and the phenomenon that the second relay K2 is stuck is effectively alleviated, and the sticking recognition accuracy of the relay is improved.

[0131] Please refer to Figure 1 The application also provides a battery management system, comprising a reference source S, a first relay K1, a second relay K2, a first sampling circuit 11, a second sampling circuit 12, a third sampling circuit 13, a first insulation detection circuit 14, a second insulation detection circuit 15 and a controller; the two ends of the first sampling circuit 11 are connected with the first relay K1 and the reference source S respectively, the two ends of the second sampling circuit 12 are connected with the second relay K2 and the reference source S respectively, the first relay K1 is further connected with the reference source S through the third sampling circuit 13, the second relay K2 is further connected with the reference source S, the first insulation detection circuit 14 is connected with the first pole of the battery and the first relay K1, the second insulation detection circuit 15 is connected with the battery and the second relay K2, the first relay K1 and the second relay K2 are further connected with the load, and the first insulation detection circuit 14 and the second insulation detection circuit 15 are grounded; the first relay K1, the second relay K2, the first sampling circuit 11, the second sampling circuit 12, the first insulation detection circuit 14 and the second insulation detection circuit 15 are connected with the controller respectively, and the controller is used for executing the steps of the above-mentioned relay sticking detection method.

[0132] Specifically, the implementation of the relay sticking detection method is as shown in the above various embodiments and the accompanying drawings, which will not be described here. In some embodiments, the first sampling circuit 11 is arranged between the load end of the first relay K1 and the first pole (e.g., the positive pole) of the reference source S, the second sampling circuit 12 is arranged between the load end of the second relay K2 and the first pole of the reference source S, the battery end of the first relay K1 is further connected to the first pole of the reference source S through the third sampling circuit 13, the battery end of the second relay K2 is further connected to the second pole (e.g., the negative pole) of the reference source S, the first end of the first insulation detection circuit 14 is connected to the first pole (e.g., the positive pole) of the battery and the battery end of the first relay K1, the first end of the second insulation detection circuit 15 is connected to the second pole (e.g., the negative pole) of the battery and the battery end of the second relay K2, the load end of the first relay K1 and the load end of the second relay K2 are further connected to the load, and the second end of the first insulation detection circuit 14 and the second end of the second insulation detection circuit 15 are grounded.

[0133] In the above battery management system, in the case that the second relay K2 is actually turned off between the reference source S and the second sampling circuit 12, the first sampling circuit 11 is controlled to be turned on to maintain the second sampling circuit 12 in the on state, which causes the sampling voltage of the second sampling circuit 12 to suddenly change and jump out of the preset voltage range. Therefore, in the case that the relay is triggered to be turned off and the above control mode is performed, if it is detected that the sampling voltage suddenly changes following the switching action, it is considered that the second relay K2 is actually turned off, i.e., there is no sticking. If it is detected that the sampling voltage does not suddenly change following the switching action, the detection result of whether the second relay K2 is stuck is determined by further combining the sampling voltage and the preset voltage range. In the above scheme, the sampling voltage of the second relay K2 suddenly changes and jumps out of the preset voltage range when the second relay K2 is not stuck by controlling the switching action of the first sampling circuit 11 and maintaining the second sampling circuit 12 in the on state. In this way, the phenomenon that the second sampling circuit 12 obtains the discharge voltage by dividing the voltage due to the fact that the equivalent capacitance of the load connected to the load end of the relay is not completely discharged, and the second relay K2 is falsely reported to be stuck, can be effectively alleviated, and the accuracy of the identification of the sticking of the relay is improved.

[0134] The application also provides a battery device comprising a battery and the above battery management system.

[0135] The structure of the battery management system, i.e., the implementation manner, is shown in the above embodiments, and will not be described herein again. In the case that the second relay K2 is actually turned off between the reference source S and the second sampling circuit 12, the battery device maintains the second sampling circuit 12 in the on state by controlling the first sampling circuit 11 to operate, which causes the sampling voltage of the second sampling circuit 12 to suddenly change, thereby jumping out of the preset voltage range. Therefore, in the case that the relay is triggered to be turned off and the above control manner is performed, if it is detected that the sampling voltage suddenly changes following the switching operation, it is considered that the second relay K2 is actually turned off, i.e., there is no sticking. If it is detected that the sampling voltage does not suddenly change following the switching operation, the detection result of whether the second relay K2 is stuck is determined in combination with the sampling voltage and the preset voltage range. The above scheme causes the sampling voltage to suddenly change when the second relay K2 is not stuck, and jumps out of the preset voltage range. In this way, the phenomenon that the second relay K2 is stuck due to the fact that the equivalent capacitance of the load connected to the load end of the relay is not completely discharged, and the second sampling circuit 12 obtains the discharge voltage through voltage division, thereby falsely reporting that the second relay K2 is stuck, can be effectively alleviated, and the accuracy of the sticking identification of the relay is improved.

[0136] The application also provides a computer device, comprising a memory and a processor, the memory stores a computer program, and the processor implements the steps of the above relay sticking detection method when executing the computer program.

[0137] In the case that the relay is triggered to be turned off, the switching operation of the first sampling circuit 11 is controlled and the second sampling circuit 12 is maintained in the on state; in the case that the voltage change rate of the sampling voltage of the second sampling circuit 12 follows the switching operation and exceeds a preset change threshold, it is determined that the second relay K2 is not stuck; and in the case that the voltage change rate of the sampling voltage does not follow the switching operation and exceeds the preset change threshold, the sticking detection result of the second relay K2 is determined according to the sampling voltage and the preset voltage range.

[0138] In some embodiments, the processor further implements the following steps when executing the computer program: in the case that the relay is triggered to be turned off, a preliminary result of the relay sticking detection is obtained; and in the case that the preliminary result includes that the second relay K2 is stuck, the switching operation of the first sampling circuit 11 is controlled and the second sampling circuit 12 is maintained in the on state.

[0139] In some embodiments, the processor further implements the following steps when executing the computer program: the switching of the first sampling circuit 11 is controlled to be turned off to disconnect the first sampling circuit 11.

[0140] In some embodiments, the processor further implements the following steps when executing the computer program: the switching of the first sampling circuit 11 is periodically controlled to be turned on and off.

[0141] In some embodiments, the processor, when executing the computer program, further implements the following steps: determining that the second relay K2 is stuck in the case that the preset sticking condition is met according to the sampling voltage and the preset voltage range; and determining that the second relay K2 is not stuck in the case that the preset sticking condition is not met according to the sampling voltage and the preset voltage range.

[0142] In some embodiments, the processor, when executing the computer program, further implements the following steps: determining that the preset sticking condition is met in the case that the first duration of the sampling voltage being in the preset voltage range reaches the first preset duration.

[0143] In some embodiments, the processor, when executing the computer program, further implements the following steps: obtaining a first ground voltage of the first insulation detection circuit 14 and a second ground voltage of the second insulation detection circuit 15; determining a voltage ratio of the first ground voltage and the second ground voltage; and determining that the preset sticking condition is met in the case that the first duration of the sampling voltage being in the preset voltage range reaches the first preset duration, and the voltage ratio is less than a preset ratio for a second preset duration in a preset interval of the first duration.

[0144] The application also provides a computer readable storage medium having a computer program stored thereon, the computer program being executed by a processor to implement the steps of the relay sticking detection method.

[0145] In the case that the relay is triggered to be turned off, the first sampling circuit 11 is controlled to switch and the second sampling circuit 12 is maintained to be turned on; in the case that the voltage change rate of the sampling voltage of the second sampling circuit 12 exceeds a preset change threshold following the switching, it is determined that the second relay K2 is not stuck; and in the case that the voltage change rate of the sampling voltage does not exceed the preset change threshold following the switching, the sticking detection result of the second relay K2 is determined according to the sampling voltage and the preset voltage range.

[0146] In some embodiments, the computer program, when executed by the processor, further implements the following steps: obtaining a preliminary result of the relay sticking detection in the case that the relay is triggered to be turned off; and controlling the first sampling circuit 11 to switch and the second sampling circuit 12 to be turned on in the case that the preliminary result includes that the second relay K2 is stuck.

[0147] In some embodiments, the computer program, when executed by the processor, further implements the following steps: controlling the switch of the first sampling circuit 11 to be turned off to disconnect the first sampling circuit 11.

[0148] In some embodiments, the computer program, when executed by the processor, further implements the following steps: periodically controlling the switch of the first sampling circuit 11 to be turned on and off.

[0149] In some embodiments, the computer program, when executed by the processor, further implements the following steps: determining that the second relay K2 is stuck in the case where it is determined that the preset sticking condition is met according to the sampling voltage and the preset voltage range; and determining that the second relay K2 is not stuck in the case where it is determined that the preset sticking condition is not met according to the sampling voltage and the preset voltage range.

[0150] In some embodiments, the computer program, when executed by the processor, further implements the following steps: determining that the preset sticking condition is met in the case where the sampling voltage is in the preset voltage range for a first duration that reaches a first preset duration.

[0151] In some embodiments, the computer program, when executed by the processor, further implements the following steps: obtaining a first ground voltage of the first insulation detection circuit 14 and a second ground voltage of the second insulation detection circuit 15; determining a voltage ratio of the first ground voltage and the second ground voltage; and determining that the preset sticking condition is met in the case where the sampling voltage is in the preset voltage range for a first duration that reaches a first preset duration, and the voltage ratio is less than a preset ratio for a second duration that reaches a second preset duration within a preset interval of the first duration.

[0152] In some embodiments, the present application further provides a computer program product comprising a computer program which, when executed by a processor, implements the following steps:

[0153] In the case where the relay is triggered to turn off, the first sampling circuit 11 is controlled to switch off and the second sampling circuit 12 is controlled to remain on; in the case where a voltage change rate of the sampling voltage of the second sampling circuit 12 exceeds a preset change threshold following the switching, it is determined that the second relay K2 is not stuck; and in the case where the voltage change rate of the sampling voltage does not exceed the preset change threshold following the switching, a sticking detection result of the second relay K2 is determined according to the sampling voltage and the preset voltage range.

[0154] In some embodiments, the computer program, when executed by the processor, further implements the following steps: obtaining a preliminary result of the relay sticking detection in the case where the relay is triggered to turn off; and controlling the first sampling circuit 11 to switch off and the second sampling circuit 12 to remain on in the case where the preliminary result includes that the second relay K2 is stuck.

[0155] In some embodiments, the computer program, when executed by the processor, further implements the following steps: controlling the switch of the first sampling circuit 11 to turn off to disconnect the first sampling circuit 11.

[0156] In some embodiments, the computer program, when executed by the processor, further implements the following steps: periodically controlling the switch of the first sampling circuit 11 to turn on and off.

[0157] In some embodiments, the computer program, when executed by the processor, further implements the following steps: determining that the second relay K2 is stuck in the case that the preset sticking condition is met according to the sampling voltage and the preset voltage range; and determining that the second relay K2 is not stuck in the case that the preset sticking condition is not met according to the sampling voltage and the preset voltage range.

[0158] In some embodiments, the computer program, when executed by the processor, further implements the following steps: determining that the preset sticking condition is met in the case that the first duration of the sampling voltage being in the preset voltage range reaches the first preset duration.

[0159] In some embodiments, the computer program, when executed by the processor, further implements the following steps: obtaining a first ground voltage of the first insulation detection circuit 14 and a second ground voltage of the second insulation detection circuit 15; determining a voltage ratio of the first ground voltage and the second ground voltage; and determining that the preset sticking condition is met in the case that the first duration of the sampling voltage being in the preset voltage range reaches the first preset duration, and the voltage ratio is less than a preset ratio for a second duration reaching a second preset duration in a preset interval of the first duration.

[0160] The computer device, the storage medium and the computer program product described above, in the case that the second relay K2 is actually turned off between the reference source S and the second sampling circuit 12, the sampling voltage of the second sampling circuit 12 will be changed abruptly by controlling the first sampling circuit 11 to act and maintaining the second sampling circuit 12 to be in conduction, so as to jump out of the preset voltage range. Therefore, in the case that the relay is triggered to be turned off and the above control mode is executed, if it is detected that the sampling voltage is changed abruptly following the switching action, it is considered that the second relay K2 is actually turned off, that is, there is no sticking. If it is detected that the sampling voltage is not changed abruptly following the switching action, the detection result of whether the second relay K2 is stuck is determined by further combining the sampling voltage and the preset voltage range. The above scheme makes the sampling voltage of the second relay K2 change abruptly and jump out of the preset voltage range in the case that the second relay K2 is not stuck by controlling the switching action of the first sampling circuit 11 and maintaining the second sampling circuit 12 to be in conduction. In this way, the phenomenon that the second relay K2 is stuck is effectively alleviated due to the fact that the equivalent capacitance of the load connected to the load end of the relay is not completely discharged, so that the discharge voltage is obtained by the second sampling circuit 12, and the sticking recognition accuracy of the relay is improved.

[0161] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a non-volatile computer readable storage medium, and when executed, can include the processes of the above-mentioned embodiment methods. In the embodiments provided in the present application, any reference to memory, database or other medium can include at least one of non-volatile memory and volatile memory. The non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical storage, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetoresistive random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. The volatile memory can include random access memory (RAM) or external cache memory, etc. As an illustration but not limitation, the RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM), etc. The database involved in the embodiments provided in the present application can include at least one of a relational database and a non-relational database. The non-relational database can include a distributed database based on a block chain, etc., without being limited thereto. The processor involved in the embodiments provided in the present application can be a general processor, a central processing unit, a graphics processing unit, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, an artificial intelligence (AI) processor, etc., without being limited thereto.

[0162] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than limit them. Although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that the technical solutions recorded in the foregoing embodiments can be modified, or some or all of the technical features can be replaced equivalently. Such modifications or replacements do not change the essence of the corresponding technical solutions, which should be covered in the scope of the claims and the specification of the present application. In particular, the technical features mentioned in each embodiment can be combined in any manner as long as there is no structural conflict. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A method for detecting relay adhesion, characterized in that, The method includes: When the relay is triggered to turn off, the first sampling circuit is controlled to switch on and the second sampling circuit is kept on. The two ends of the first sampling circuit are respectively connected to the first relay and the reference source, the two ends of the second sampling circuit are respectively connected to the second relay and the reference source, the first relay is also connected to the reference source through the third sampling circuit, and the second relay is also connected to the reference source. If the rate of change of the sampling voltage of the second sampling circuit exceeds a preset threshold following the switching action, it is determined that the second relay has not stuck. If the rate of change of the sampled voltage does not exceed a preset threshold following the switching action, the adhesion detection result of the second relay is determined based on the sampled voltage and the preset voltage range.

2. The relay adhesion detection method according to claim 1, characterized in that, The step of controlling the first sampling circuit to switch on and maintaining the second sampling circuit on when the relay is triggered to turn off includes: When the relay is triggered and turned off, obtain preliminary results of the relay sticking detection; If the preliminary results include the second relay sticking, the first sampling circuit is controlled to switch on and the second sampling circuit is kept on.

3. The relay adhesion detection method according to claim 1, characterized in that, The control of the first sampling circuit switch operation includes: The switch of the first sampling circuit is turned off to disconnect the first sampling circuit.

4. The relay adhesion detection method according to claim 1, characterized in that, The control of the first sampling circuit switch operation includes: The switching on and off of the first sampling circuit is controlled periodically.

5. The relay adhesion detection method according to any one of claims 1-4, characterized in that, The step of determining the adhesion detection result of the second relay based on the sampled voltage and the preset voltage range includes: If, based on the sampling voltage and the preset voltage range, the preset adhesion condition is met, it is determined that the second relay has become stuck. If, based on the sampled voltage and the preset voltage range, it is determined that the preset adhesion condition is not met, then it is determined that the second relay has not adhered.

6. The relay adhesion detection method according to claim 5, characterized in that, The method further includes: If the sampling voltage is within the preset voltage range for a first duration that reaches a first preset duration, it is determined that the preset adhesion condition is met.

7. The relay adhesion detection method according to claim 5, characterized in that, The method further includes: The first voltage to ground of the first insulation detection circuit and the second voltage to ground of the second insulation detection circuit are obtained; wherein the first insulation detection circuit is connected to the first relay and the third sampling circuit, and the second insulation detection circuit is connected to the second relay and the reference source; Determine the voltage ratio between the first voltage to ground and the second voltage to ground; If the sampling voltage is within the preset voltage range for a first duration of a first preset duration, and the voltage ratio is less than the preset ratio for a second duration within a preset interval of the first duration, then the preset adhesion condition is determined to be satisfied.

8. A relay adhesion detection device, characterized in that, The device includes: A switch control component is used to control the switching action of a first sampling circuit and maintain the conduction of a second sampling circuit when the relay is triggered to turn off; wherein, the two ends of the first sampling circuit are respectively connected to a first relay and a reference source, the two ends of the second sampling circuit are respectively connected to a second relay and the reference source, the first relay is also connected to the reference source through a third sampling circuit, and the second relay is also connected to the reference source; A follow-up verification component is used to determine that the second relay has not stuck when the rate of change of the sampled voltage of the second sampling circuit exceeds a preset change threshold following the switching action; An adhesion detection component is used to determine the adhesion detection result of the second relay based on the sampled voltage and a preset voltage range, provided that the voltage change rate of the sampled voltage does not exceed a preset change threshold in accordance with the switching action.

9. A battery management system, characterized in that, It includes a reference source, a first relay, a second relay, a first sampling circuit, a second sampling circuit, a third sampling circuit, a first insulation detection circuit, a second insulation detection circuit, and a controller; The first sampling circuit is connected to the first relay and the reference source at both ends, the second sampling circuit is connected to the second relay and the reference source at both ends, the first relay is also connected to the reference source through the third sampling circuit, the second relay is also connected to the reference source, the first insulation detection circuit is connected to the battery and the first relay, the second insulation detection circuit is connected to the battery and the second relay, the first relay and the second relay are also connected to the electrical load, and the first insulation detection circuit and the second insulation detection circuit are grounded. The first relay, the second relay, the first sampling circuit, the second sampling circuit, the first insulation detection circuit, and the second insulation detection circuit are respectively connected to the controller, and the controller is used to execute the steps of the relay adhesion detection method according to any one of claims 1 to 7.

10. A battery device, characterized in that, Includes a battery and the battery management system as described in claim 9.

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