Relay fault detection method and device, battery management system and medium

Abstract

The invention provides a relay fault detection method and device, a battery management system and a medium. The method comprises the following steps: acquiring a current charging scheme and a current charging electrical stage; in each charging electrical stage, the following operations are executed: a relay to be detected corresponding to the current charging electrical stage is determined according to a current charging scheme and a battery pack-relay circuit topological relation; for each to-be-detected relay, obtaining detection voltage values at the two ends of the to-be-detected relay according to the circuit topological relation; and obtaining a fault detection result of the to-be-detected relay according to the detection voltage value and an expected voltage value of the to-be-detected relay in the current charging electrical stage. According to the invention, on the premise of satisfying the function safety voltage sampling ASIL C diagnosis coverage rate, the diagnosis robustness of the battery management system is improved, and fault false alarms are reduced; and the position of the virtual connection sampling line can be accurately positioned, and the troubleshooting difficulty is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of battery management, and in particular to a relay fault detection method, device, battery management system and medium. Background Art

[0002] With the popularity of electric vehicles, the requirements for electric vehicle safety are getting higher and higher. Electric vehicles use the battery management system (BMS) to control the opening and closing of the high-voltage relay in the battery pack to manage the high-voltage power on and off of the entire vehicle. Taking the split-pack charging solution as an example, the BMS needs to control and diagnose the relevant relays in the split-pack charging solution and make corresponding fault responses to ensure that the battery operates in a safe environment. Fault diagnosis includes driver-level diagnosis and contact diagnosis of the relay on the charging side, thereby ensuring the normal use of the relay and the safety of the battery pack, thereby ensuring the high-voltage power distribution and functional safety of the entire vehicle.

[0003] However, during the frequent power-on and power-off of electric vehicles, relays are subject to high temperatures, vibrations, high current shocks, etc., which may cause electrical failures in the relays or even cause the relays to malfunction. When an electrical failure or contact failure occurs in the relay, the relay's erroneous response will cause serious damage to the entire high-voltage system. Therefore, there are high requirements for system robustness and diagnostic coverage. How to provide a relay fault detection method to detect whether the relay has adhesion or jamming failures is becoming one of the technical problems that technicians in this field need to solve.

[0004] It should be noted that the information disclosed in the background technology section of the invention is only intended to deepen the understanding of the general background technology of the invention, and should not be regarded as an admission or suggestion in any form that the information constitutes prior art already known to those skilled in the art. Summary of the invention

[0005] The purpose of the present invention is to provide a relay fault detection method, device, battery management system and medium. The present invention can improve the diagnostic robustness of the battery management system and reduce false fault alarms while meeting the ASIL C diagnostic coverage of functional safety voltage sampling; and can accurately locate the position of the virtual connection sampling line, reduce the difficulty of troubleshooting, and save manpower and material costs.

[0006] In order to achieve the above object, the present invention is implemented by the following technical scheme: a relay fault detection method is used to detect whether the relay is faulty when the battery management system controls the relay to be turned on and / or off to cut the battery pack, and the relay fault detection method includes:

[0007] Obtaining the current charging scheme and the current charging electrical stage; the charging electrical stage includes the upper high-voltage charging pre-stage, the upper high-voltage charging stage, and the charging completion stage;

[0008] In each of the charging electrical phases, the following operations are performed:

[0009] Determine the relay to be detected corresponding to the current charging electrical stage according to the current charging scheme and the circuit topology relationship between the battery pack and the relay;

[0010] For each of the relays to be detected, the detection voltage values ​​at both ends of the relay to be detected are obtained according to the circuit topology relationship; and the fault detection result of the relay to be detected is obtained according to the detection voltage value and the expected voltage value of the relay to be detected in the current charging electrical stage.

[0011] Optionally, the relay fault detection method further includes:

[0012] Determining the current charging scheme according to the battery pack cutting instruction of the battery management system;

[0013] The current electrical charging stage is determined according to the current charging scheme and the relay switch control instruction of the battery management system.

[0014] Optionally, the circuit topology of the battery pack-relay includes two relays for connecting the positive charging electrode and the negative charging electrode, respectively, and at least three relays for connecting the battery pack; the on and / or off states of the at least three relays for connecting the battery pack are used to change the connection state between the battery packs to achieve at least two different charging schemes;

[0015] The step of determining the relay to be detected corresponding to the current charging electrical stage according to the current charging scheme and the circuit topology relationship between the battery pack and the relay includes:

[0016] In the pre-high voltage charging stage, a relay used to connect the battery pack is used as the relay to be detected;

[0017] In the upper high-voltage charging stage and the charging completion stage, the relay used to connect the charging positive electrode and the charging negative electrode, and the relay used to connect the battery pack that is in a conductive state during the charging process of the current charging scheme are used as the relays to be detected.

[0018] Optionally, obtaining a fault detection result of the relay to be detected according to the detection voltage value and an expected voltage value of the relay to be detected in the current charging electrical stage includes:

[0019] If the current charging electrical stage is the upper high-voltage charging pre-stage or the charging completion stage, it is determined whether the absolute value of the difference between the detection voltage value and the expected voltage value is less than a first preset value, and if so, the relay to be detected has a sticking fault;

[0020] If the current charging electrical stage is the upper high-voltage charging stage, it is determined whether the absolute value of the difference between the detected voltage value and the expected voltage value is greater than a second preset value. If so, the relay to be detected has a stuck fault.

[0021] In order to achieve the above object, the present invention further provides a relay fault detection device, which is used to detect whether the relay has a fault when the battery management system controls the relay to be turned on and / or off to perform battery pack switching. The relay fault detection device includes:

[0022] A charging scheme and charging stage acquisition unit is configured to acquire the current charging scheme and the current charging electrical stage; the charging electrical stage includes a stage before upper high-voltage charging, an upper high-voltage charging stage, and a charging completion stage;

[0023] The fault detection execution unit is configured to perform the following operations in each of the charging electrical stages:

[0024] Determine the relay to be detected corresponding to the current charging electrical stage according to the current charging scheme and the circuit topology relationship between the battery pack and the relay;

[0025] For each of the relays to be detected, the detection voltage values ​​at both ends of the relay to be detected are obtained according to the circuit topology relationship; and the fault detection result of the relay to be detected is obtained according to the detection voltage value and the expected voltage value of the relay to be detected in the current charging electrical stage.

[0026] Optionally, the circuit topology relationship of the battery pack-relay includes a first battery pack, a second battery pack, a first relay, a second relay, a third relay, a fourth relay and a fifth relay; the fault detection execution unit includes a first voltage detection unit, a second voltage detection unit, a third voltage detection unit, a fourth voltage detection unit and a fifth voltage detection unit for obtaining the detection voltage value; the first end of the first battery pack, the first end of the first relay and the first end of the second relay are coupled to a first node, and the first voltage detection unit is set at the first node; the second end of the second relay, the first end of the second battery pack and the first end of the third relay are coupled to a second node, and the second voltage detection unit is set at the second node; the second end of the first relay, the second end of the second battery pack and the first end of the fourth relay are coupled to a third node, and the third voltage detection unit is set at the third node; the second end of the fourth relay is coupled to the positive charging electrode at a fourth node, and the fourth voltage detection unit is set at the fourth node; the second end of the first battery pack and the second end of the third relay are coupled to the first end of the fifth relay, the second end of the fifth relay is coupled to the negative charging electrode at a fifth node, and the fifth voltage detection unit is set at the fifth node.

[0027] Optionally, the circuit topology relationship of the battery pack-relay is configured to implement a first voltage charging scheme when the first relay is turned on, the third relay is turned on, and the second relay is turned off; and implement a second voltage charging scheme when the first relay is turned off, the third relay is turned off, and the second relay is turned on;

[0028] The fault detection execution unit is configured to obtain, for each of the relays to be detected, a detection voltage value at both ends of the relay to be detected according to the circuit topology relationship, including:

[0029] Acquire detection voltage values ​​at both ends of the first relay and / or the third relay according to the voltage values ​​collected by the first voltage detection unit and the third voltage detection unit;

[0030] Acquire detection voltage values ​​at both ends of the second relay according to the voltage values ​​collected by the first voltage detection unit and the second voltage detection unit;

[0031] Acquire detection voltage values ​​at both ends of the fourth relay according to the voltage values ​​collected by the first voltage detection unit and the fourth voltage detection unit;

[0032] The detection voltage value of the fifth relay is obtained according to the voltage value collected by the fourth voltage detection unit to detect whether the fifth relay has a sticking fault; the detection voltage value of the fifth relay is obtained according to the voltage values ​​collected by the fourth voltage detection unit and the fifth voltage detection unit to detect whether the fifth relay has a adhesion fault.

[0033] In order to achieve the above object, the present invention further provides a battery management system, which includes any one of the relay fault detection devices described above.

[0034] Optionally, the battery management system also includes a main controller and at least two slave controllers, and the main controller and the slave controllers are connected in a daisy chain manner; the main controller is used to control the on / off state of the relay to perform battery pack cutting; the slave controller is used to obtain the cell voltage of the battery pack corresponding to the slave controller and the temperature of each battery module in each of the battery packs.

[0035] In order to achieve the above object, the present invention further provides a readable storage medium, wherein the readable storage medium stores a computer program, and when the computer program is executed by a processor, any of the above relay fault detection methods is implemented.

[0036] Compared with the prior art, the relay fault detection method, device, battery management system and medium provided by the present invention have the following advantages:

[0037] The relay fault detection method provided by the present invention, the relay fault detection method provided by the present invention, first obtains the current charging scheme and the current charging electrical stage, and the charging electrical stage includes the upper high-voltage charging pre-stage, the upper high-voltage charging stage and the charging completion stage. Thus, a solid foundation is laid for determining the relay to be detected for different charging schemes and different charging stages. Then, in each of the charging electrical stages, the relay to be detected corresponding to the current charging electrical stage is determined according to the current charging scheme and the circuit topology relationship between the battery pack and the relay. Thus, the leakage detection of the relay during the battery pack cutting process can be avoided, so that the detection coverage can be guaranteed. Finally, for each of the relays to be detected, the detection voltage values ​​at both ends of the relay to be detected are obtained according to the circuit topology relationship; and the fault detection result of the relay to be detected is obtained according to the detection voltage value and the expected voltage value of the relay to be detected in the current charging electrical stage. Thus, the present invention can improve the diagnostic robustness of the battery management system and reduce false fault alarms under the premise of meeting the diagnostic coverage of functional safety voltage sampling ASIL C; and can accurately locate the position of the virtual connection sampling line, reduce the difficulty of troubleshooting, and save manpower and material costs.

[0038] Since the relay fault detection device, battery management system and medium provided by the present invention belong to the same inventive concept as the relay fault detection method provided by the present invention, the relay fault detection device, battery management system and medium provided by the present invention at least have all the advantages of the relay fault detection method provided by the present invention. For details about the beneficial effects of the relay fault detection device, battery management system and medium provided by the present invention, please refer to the above description of the beneficial effects of the relay fault detection method provided by the present invention, and no further details will be given here. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 A schematic diagram of the overall flow of a relay fault detection method provided in Embodiment 1 of the present invention;

[0040] Figure 2 A schematic diagram of a circuit topology relationship between a battery pack and a relay using the relay fault detection method provided by the present invention;

[0041] Figure 3 A structural block diagram of a relay fault detection device provided by a second embodiment of the present invention;

[0042] Figure 4 A schematic diagram of a circuit topology relationship between a battery pack and a relay using the relay fault detection device provided by the present invention;

[0043] Figure 5 A schematic block diagram of a battery management system provided in a third embodiment of the present invention;

[0044] The reference numerals are as follows:

[0045] Battery pack-B01, B02, B03, B0n; Relay-S01, S02, S03, S04, S05, S07, Sp, Sn;

[0046] Relay fault detection device-100, charging scheme and charging stage acquisition unit-110, fault detection execution unit-120;

[0047] First battery pack-B11, second battery pack-B12, first relay-S11, second relay-S12, third relay-S13, fourth relay-S14, fifth relay-S15;

[0048] Fuses-F11, F12, current sensing units-CS1, CS2;

[0049] A first voltage detection unit-V11, a second voltage detection unit-V12, a third voltage detection unit-V13, a fourth voltage detection unit-V14, and a fifth voltage detection unit-V15;

[0050] Master controller-210, slave controller-220. DETAILED DESCRIPTION

[0051] The following is a further detailed description of a relay fault detection method, device, battery management system and medium proposed by the present invention in conjunction with the accompanying drawings. According to the following description, the advantages and features of the present invention will be clearer. It should be noted that the drawings are in a very simplified form and all use non-precise proportions, which are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present invention. In order to make the purposes, features and advantages of the present invention more obvious and easy to understand, please refer to the accompanying drawings. It should be noted that the structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present invention. Any modification of the structure, change in the proportional relationship or adjustment of the size, in the case of the same or similar effects and purposes that can be achieved by the present invention, should still fall within the scope of the technical content disclosed by the present invention. The specific design features of the present invention disclosed herein include, for example, specific dimensions, directions, positions and shapes, which will be determined in part by the specific environment to be applied and used. And, in the embodiments described below, sometimes the same figure mark is used in common between different drawings to represent the same part or part with the same function, and its repeated description is omitted. In this specification, similar reference numerals and letters are used to refer to similar items, and therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures. In addition, if the method described herein includes a series of steps, the order of these steps presented herein is not necessarily the only order in which these steps can be performed, and some of the steps described may be omitted and / or some other steps not described herein may be added to the method.

[0052] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements. The singular forms "a", "an" and "the" include plural objects, the term "or" is generally used in a sense including "and / or", the term "several" is generally used in a sense including "at least one", and the term "at least two" is generally used in a sense including "two or more". In addition, the terms "first", "second" and "third" are used for descriptive purposes only and are not to be understood as indicating or suggesting relative importance or implicitly indicating the number of the indicated technical features.

[0053] It should be understood that when an element is referred to as being "connected to" or "coupled to" another element, it may be directly connected to the other element or there may be intervening elements. Conversely, when an element is referred to as being "directly connected to" another element, there are no intervening elements.

[0054] The core idea of ​​the present invention is to provide a relay fault detection method, device, battery management system and medium. The present invention can improve the diagnostic robustness of the battery management system and reduce false fault alarms while meeting the ASIL C diagnostic coverage of functional safety voltage sampling; and can accurately locate the position of the virtual connection sampling line, reduce the difficulty of troubleshooting, and save manpower and material costs.

[0055] It should be noted that the relay fault detection method and readable storage medium provided by the present invention can be applied to the relay fault detection device and battery management system provided by the present invention, and the relay fault detection method, device, battery management system and medium provided by the present invention can be applied to vehicles. It should be understood that the terms "vehicle" or "vehicle" or other similar terms used herein include general motor vehicles, such as passenger vehicles including sports utility vehicles (SUVs), buses, trucks, various commercial vehicles, and hybrid vehicles, electric vehicles, plug-in hybrid electric vehicles, and fuel cell vehicles.

[0056] Embodiment 1

[0057] This embodiment provides a relay fault detection method. It is used to detect whether the relay is faulty when the battery management system controls the relay to be turned on and / or off to perform battery pack switching. For details, see Figure 1 , Figure 1 The overall flow chart of the relay fault detection method provided by the first embodiment of the present invention is as follows. Figure 1 It can be seen that the relay fault detection method comprises:

[0058] S100: Obtaining the current charging scheme and the current charging electrical stage; the charging electrical stage includes a stage before upper high-voltage charging, an upper high-voltage charging stage, and a charging completion stage;

[0059] S200: In each of the charging electrical stages, the following operations are performed:

[0060] Determine the relay to be detected corresponding to the current charging electrical stage according to the current charging scheme and the circuit topology relationship between the battery pack and the relay;

[0061] For each of the relays to be detected, the detection voltage values ​​at both ends of the relay to be detected are obtained according to the circuit topology relationship; and the fault detection result of the relay to be detected is obtained according to the detection voltage value and the expected voltage value of the relay to be detected in the current charging electrical stage.

[0062] It can be seen that the relay fault detection method provided by the present invention first obtains the current charging scheme and the current charging electrical stage, and the charging electrical stage includes the upper high-voltage charging pre-stage, the upper high-voltage charging stage and the charging completion stage. Thus, a solid foundation is laid for determining the relay to be detected for different charging schemes and different charging stages. Then, in each of the charging electrical stages, the relay to be detected corresponding to the current charging electrical stage is determined according to the current charging scheme and the circuit topology relationship between the battery pack and the relay. Thus, the leakage detection of the relay during the battery pack cutting process can be avoided, so that the detection coverage can be guaranteed. Finally, for each of the relays to be detected, the detection voltage values ​​at both ends of the relay to be detected are obtained according to the circuit topology relationship; and the fault detection result of the relay to be detected is obtained according to the detection voltage value and the expected voltage value of the relay to be detected in the current charging electrical stage. Thus, the present invention can improve the diagnostic robustness of the battery management system and reduce false fault alarms under the premise of meeting the diagnostic coverage of functional safety voltage sampling ASIL C; and can accurately locate the position of the virtual connection sampling line, reduce the difficulty of troubleshooting, and save manpower and material costs.

[0063] Preferably, in some exemplary embodiments, the relay fault detection method further includes obtaining the current charging scheme and the current charging electrical stage in the following manner:

[0064] Determining the current charging scheme according to the battery pack cutting instruction of the battery management system;

[0065] The current electrical charging stage is determined according to the current charging scheme and the relay switch control instruction of the battery management system.

[0066] Therefore, the relay fault detection method provided by the present invention determines the current charging scheme according to the battery pack cutting instruction of the battery management system, and determines the charging electrical stage according to the current charging scheme and the relay switch control instruction, which can not only further improve the diagnostic efficiency of the present invention, but also lay a solid foundation for more effectively determining the relay to be detected.

[0067] Preferably, in some of the exemplary embodiments, please refer to the attached Figure 2 , Figure 2 The figure is a schematic diagram of a circuit topology relationship between a battery pack and a relay using the relay fault detection method provided by the present invention. Figure 2 It can be seen that the circuit topology relationship of the battery pack-relay includes two relays Sp and Sn for connecting the positive charging pole and the negative charging pole respectively, and at least three relays B01, B02, B03, ..., B0n (for example, when battery packs B01 and B02 are included, including relays S01, S04 and S06) for connecting the battery pack; by changing the on and / or off state of the relays for connecting the battery pack, at least two different charging schemes can be realized.

[0068] The step of determining the relay to be detected corresponding to the current charging electrical stage according to the current charging scheme and the circuit topology relationship between the battery pack and the relay includes:

[0069] In the pre-high voltage charging stage, a relay used to connect the battery pack is used as the relay to be detected;

[0070] In the upper high-voltage charging stage and the charging completion stage, the relay used to connect the charging positive electrode and the charging negative electrode, and the relay used to connect the battery pack that is in a conductive state during the charging process of the current charging scheme are used as the relays to be detected.

[0071] like Figure 2As shown, illustratively, in one specific example, if battery pack B01, battery pack B02 and battery pack B03 are connected in parallel to implement one of the charging schemes, the relays connecting battery pack B01, battery pack B02 and battery pack B03 are S01, S02, S03, S04, S05, S06 and S07, and the relays used to connect the positive charging pole and the negative charging pole are Sp and Sn respectively. In the pre-high-voltage charging stage, the relays to be detected are S01, S02, S03, S04, S05, S06 and S07; in the high-voltage charging stage and the charging completion stage, the relays to be detected are Sp, Sn and the relays S01, S02, S03, S06 and S07 that are in the on state during the charging process of the charging scheme.

[0072] It should be noted that, as can be understood by those skilled in the art, the present invention does not impose too many restrictions on the circuit topology relationship of the battery pack-relay and the number of charging schemes that can be implemented. For ease of understanding and description, the following description is based on an example in which the circuit topology relationship of the battery pack-relay includes a first battery pack and a second battery pack.

[0073] Preferably, in some exemplary embodiments, obtaining the fault detection result of the relay to be detected according to the detection voltage value and the expected voltage value of the relay to be detected in the current charging electrical stage includes:

[0074] If the current charging electrical stage is the upper high-voltage charging pre-stage or the charging completion stage, it is determined whether the absolute value of the difference between the detection voltage value and the expected voltage value is less than a first preset value, and if so, the relay to be detected has a sticking fault;

[0075] If the current charging electrical stage is the upper high-voltage charging stage, it is determined whether the absolute value of the difference between the detected voltage value and the expected voltage value is greater than a second preset value. If so, the relay to be detected has a stuck fault.

[0076] Configured in this way, the relay fault detection method provided by the present invention can timely detect relay faults and effectively avoid overcharging of the battery pack by judging whether the relay to be detected has a sticking fault in the pre-high-voltage charging stage and in the charging completion stage, thereby better protecting the safety of the battery pack and extending its service life. By detecting whether the relay to be detected has a stuck fault in the high-voltage charging stage, relay faults can be timely detected and the normal charging of the battery pack can be ensured. It can be seen that the relay fault detection method provided by the present invention can ensure the normal use of the relay and the safety of the battery pack.

[0077] Embodiment 2

[0078] Based on the same inventive concept, this embodiment provides a relay fault detection device for detecting whether the relay is faulty when the battery management system controls the relay to be turned on and / or off to perform battery pack switching. Figure 3 ,like Figure 3 As shown, the relay fault detection device includes a charging scheme and charging stage acquisition unit 110 and a fault detection execution unit 120. Specifically, the charging scheme and charging stage acquisition unit 110 is configured to acquire the current charging scheme and the current charging electrical stage; the charging electrical stage includes the upper high-voltage charging pre-stage, the upper high-voltage charging stage and the charging completion stage. The fault detection execution unit 120 is configured to perform the following operations in each of the charging electrical stages: determine the relay to be detected corresponding to the current charging electrical stage according to the current charging scheme and the circuit topology relationship between the battery pack and the relay; for each of the relays to be detected, obtain the detection voltage value at both ends of the relay to be detected according to the circuit topology relationship; and obtain the fault detection result of the relay to be detected according to the detection voltage value and the expected voltage value of the relay to be detected in the current charging electrical stage.

[0079] Therefore, the relay fault detection device provided by the present invention can improve the diagnostic robustness of the battery management system and reduce false fault alarms while meeting the ASIL C diagnostic coverage of functional safety voltage sampling; and can accurately locate the position of the virtual connection sampling line, reduce the difficulty of troubleshooting, and save manpower and material costs.

[0080] Since the relay fault detection device provided by the present invention has the same basic principle as the relay fault detection method provided by the present invention, for the parts not mentioned in this embodiment, please refer to the relevant description of the first embodiment for adaptive understanding.

[0081] See also Figure 4 , Figure 4 FIG. 1 is a schematic diagram of a circuit topology relationship between a battery pack and a relay using the relay fault detection device provided in this embodiment. Figure 4It can be seen that in this example, the circuit topology relationship of the battery pack-relay includes a first battery pack B11 and a second battery pack B12, and a first relay S11, a second relay S12, a third relay S13, a fourth relay S14 and a fifth relay S15; the fault detection execution unit 120 includes a first voltage detection unit V11, a second voltage detection unit V12, a third voltage detection unit V13, a fourth voltage detection unit V14 and a fifth voltage detection unit V15 for obtaining the detection voltage value; a first end of the first battery pack B11, a first end of the first relay S11 and a first end of the second relay S12 are coupled to a first node, and the first voltage detection unit V11 is set at the first node; a second end of the second relay S12, a second end of the second battery pack B11, a first end of the first relay S11 and a first end of the second relay S12 are coupled to a first node, and the first voltage detection unit V11 is set at the first node; a second end of the second relay S12, a second end of the second battery pack B11, a second end of the second relay S12, a third end of the second relay S13, a fourth relay S14 and a fifth relay S15 The first end of the battery pack B12 and the first end of the third relay S13 are coupled to the second node, and the second voltage detection unit V12 is set at the second node; the second end of the first relay S11, the second end of the second battery pack B12 and the first end of the fourth relay S14 are coupled to the third node, and the third voltage detection unit V13 is set at the third node; the second end of the fourth relay S14 is coupled to the positive charging electrode at the fourth node, and the fourth voltage detection unit V14 is set at the fourth node; the second end of the first battery pack B11 and the second end of the third relay S13 are coupled to the first end of the fifth relay S15, the second end of the fifth relay S15 is coupled to the negative charging electrode at the fifth node, and the fifth voltage detection unit V15 is set at the fifth node.

[0082] More specifically, as a preferred embodiment, Figure 4 As shown, the circuit topology of the battery pack-relay also includes fuses F11, F12 and current detection units CS1, CS2, etc., thereby further ensuring the safe use of the relay and the battery pack.

[0083] Preferably, in some exemplary embodiments, the circuit topology relationship of the battery pack-relay is configured to implement a first voltage charging scheme when the first relay S11 is turned on, the third relay S13 is turned on, and the second relay S12 is turned off; and to implement a second voltage charging scheme when the first relay S11 is turned off, the third relay S13 is turned off, and the second relay S12 is turned on.

[0084] Correspondingly, the fault detection execution unit 120 is configured to obtain, for each of the relays to be detected, a detection voltage value across the relay to be detected according to the circuit topology relationship, including:

[0085] Acquire detection voltage values ​​across the first relay S11 and / or the third relay S13 according to the voltage values ​​collected by the first voltage detection unit V11 and the third voltage detection unit V13;

[0086] Acquire detection voltage values ​​at both ends of the second relay S12 according to the voltage values ​​collected by the first voltage detection unit V11 and the second voltage detection unit V12;

[0087] Acquire detection voltage values ​​at both ends of the fourth relay S14 according to the voltage values ​​collected by the first voltage detection unit V11 and the fourth voltage detection unit V14;

[0088] The detection voltage value of the fifth relay S15 is obtained according to the voltage value collected by the fourth voltage detection unit V14 to detect whether the fifth relay S15 has a sticking fault; the detection voltage value of the fifth relay S15 is obtained according to the voltage values ​​collected by the fourth voltage detection unit V14 and the fifth voltage detection unit V15 to detect whether the fifth relay S15 has a sticking fault.

[0089] For example, if the full charge voltage of the first battery pack B11 and the second battery pack B12 are both 400V, then Figure 4 The circuit topology shown can realize two charging schemes of 400V (the first battery pack B11 and the second battery pack B12 are connected in parallel to realize the first charging scheme) and 800V (the first battery pack B11 and the second battery pack B12 are connected in series to realize the second charging scheme). The following respectively describes the different charging electrical stages of the two different charging schemes of 400V and 800V as follows:

[0090] 1. 400V charging solution (i.e., the first battery pack B11 and the second battery pack B12 are connected in parallel)

[0091] (1) Stage before high-voltage charging

[0092] The first voltage detection unit V11 and the third voltage detection unit V13 are used to respectively determine whether the first relay S11 and the third relay S13 have a sticking fault: that is, if the absolute value of the difference between the detection voltage value detected by the first voltage detection unit V11 and the detection voltage value detected by the third voltage detection unit V13 is less than the first preset value, then the first relay S11 or the third relay S13 has a sticking fault; if not, then the first relay S11 and the third relay S13 do not have a sticking fault. Similarly, the first voltage detection unit V11 and the second voltage detection unit V12 are used to determine whether the second relay S12 has a sticking fault: that is, if the absolute value of the difference between the detection voltage value detected by the first voltage detection unit V11 and the detection voltage value detected by the second voltage detection unit V12 is less than the first preset value, then the second relay S12 has a sticking fault; if not, then the second relay S12 does not have a sticking fault.

[0093] (2) High-voltage charging stage

[0094] The first voltage detection unit V11 and the third voltage detection unit V13 are used to respectively determine whether the first relay S11 and the third relay S13 have a stuck fault: that is, if the absolute value of the difference between the detection voltage value detected by the first voltage detection unit V11 and the detection voltage value detected by the third voltage detection unit V13 is greater than the second preset value, the first relay S11 or the third relay S13 has a stuck fault; if not, the first relay S11 and the third relay S13 do not have a stuck fault. Similarly, the first voltage detection unit V11 and the fourth voltage detection unit V14 are used to determine whether the fourth relay S14 has a stuck fault: that is, if the absolute value of the difference between the detection voltage value detected by the first voltage detection unit V11 and the detection voltage value detected by the fourth voltage detection unit V14 is greater than the second preset value, the fourth relay S14 has a stuck fault; if not, the fourth relay S14 does not have a stuck fault.

[0095] In addition, the fourth voltage detection unit V14 is used to determine whether the fifth relay S15 has a stuck fault: that is, if the voltage value detected by the fourth voltage detection unit V14 is greater than the expected voltage value, the fifth relay S15 has a stuck fault; if not, the fifth relay S15 does not have a stuck fault.

[0096] (3) Charging completion stage

[0097] The fourth voltage detection unit V14 and the fifth voltage detection unit V15 are used to determine whether the fifth relay S15 has a sticking fault: that is, if the absolute value of the difference between the detection voltage value detected by the fourth voltage detection unit V14 and the detection voltage value detected by the fifth voltage detection unit V15 is less than the first preset value, the fifth relay S15 has a sticking fault; if not, the fifth relay S15 does not have a sticking fault. Similarly, the first voltage detection unit V11 and the fourth voltage detection unit V14 are used to determine whether the fourth relay S14 has a sticking fault: that is, if the absolute value of the difference between the detection voltage value detected by the first voltage detection unit V11 and the detection voltage value detected by the fourth voltage detection unit V14 is less than the first preset value, the fourth relay S14 has a sticking fault; if not, the fourth relay S14 does not have a sticking fault. The first voltage detection unit V11 and the third voltage detection unit V13 are used to respectively determine whether the first relay S11 and the third relay S13 have a sticking fault: that is, if the absolute value of the difference between the detection voltage value detected by the first voltage detection unit V11 and the detection voltage value detected by the third voltage detection unit V13 is less than a first preset value, then the first relay S11 or the third relay S13 has a sticking fault; if not, then the first relay S11 and the third relay S13 do not have a sticking fault.

[0098] 2. 800V charging solution (i.e., the first battery pack B11 and the second battery pack B12 are connected in series)

[0099] (1) Stage before high-voltage charging

[0100] The first voltage detection unit V11 and the third voltage detection unit V13 are used to respectively determine whether the first relay S11 and the third relay S13 have a sticking fault: that is, if the absolute value of the difference between the detection voltage value detected by the first voltage detection unit V11 and the detection voltage value detected by the third voltage detection unit V13 is less than the first preset value, then the first relay S11 or the third relay S13 has a sticking fault; if not, then the first relay S11 and the third relay S13 do not have a sticking fault. Similarly, the first voltage detection unit V11 and the second voltage detection unit V12 are used to determine whether the second relay S12 has a sticking fault: that is, if the absolute value of the difference between the detection voltage value detected by the first voltage detection unit V11 and the detection voltage value detected by the second voltage detection unit V12 is less than the first preset value, then the second relay S12 has a sticking fault; if not, then the second relay S12 does not have a sticking fault.

[0101] (2) High-voltage charging stage

[0102] The first voltage detection unit V11 and the second voltage detection unit V12 are used to determine whether the second relay S12 has a stuck fault: that is, if the absolute value of the difference between the detection voltage value detected by the first voltage detection unit V11 and the detection voltage value detected by the second voltage detection unit V12 is greater than the second preset value, the second relay S12 has a stuck fault; if not, the second relay S12 does not have a stuck fault. Similarly, the first voltage detection unit V11 and the fourth voltage detection unit V14 are used to determine whether the fourth relay S14 has a stuck fault: that is, if the absolute value of the difference between the detection voltage value detected by the first voltage detection unit V11 and the detection voltage value detected by the fourth voltage detection unit V14 is greater than the second preset value, the fourth relay S14 has a stuck fault; if not, the fourth relay S14 does not have a stuck fault.

[0103] In addition, the fourth voltage detection unit V14 is used to determine whether the fifth relay S15 has a stuck fault: that is, if the voltage value detected by the fourth voltage detection unit V14 is greater than the expected voltage value, the fifth relay S15 has a stuck fault; if not, the fifth relay S15 does not have a stuck fault.

[0104] (3) Charging completion stage

[0105] The fourth voltage detection unit V14 and the fifth voltage detection unit V15 are used to determine whether the fifth relay S15 has a sticking fault: that is, if the absolute value of the difference between the detection voltage value detected by the fourth voltage detection unit V14 and the detection voltage value detected by the fifth voltage detection unit V15 is less than the first preset value, the fifth relay S15 has a sticking fault; if not, the fifth relay S15 does not have a sticking fault. Similarly, the first voltage detection unit V11 and the fourth voltage detection unit V14 are used to determine whether the fourth relay S14 has a sticking fault: that is, if the absolute value of the difference between the detection voltage value detected by the first voltage detection unit V11 and the detection voltage value detected by the fourth voltage detection unit V14 is less than the first preset value, the fourth relay S14 has a sticking fault; if not, the fourth relay S14 does not have a sticking fault. The first voltage detection unit V11 and the second voltage detection unit V12 are used to determine whether the second relay S12 has a adhesion fault: that is, if the absolute value of the difference between the detection voltage value detected by the first voltage detection unit V11 and the detection voltage value detected by the second voltage detection unit V12 is less than the first preset value, then the second relay S12 has a adhesion fault; if not, then the second relay S12 does not have a adhesion fault.

[0106] It should be noted that, as those skilled in the art can understand, the present invention does not limit the specific values ​​of the first preset value, the second preset value and the expected voltage value, and the specific values ​​of the first preset value, the second preset value and the expected voltage value should be reasonably set according to actual needs.

[0107] Embodiment 3

[0108] Based on the same inventive concept, this embodiment provides a battery management system, which includes the relay fault detection device 100 described in any of the above embodiments.

[0109] Since the battery management system provided by the present invention and the relay fault detection device provided by the present invention belong to the same inventive concept, the battery management system provided by the present invention at least has all the advantages of the relay fault detection device provided by the present invention. For details on the beneficial effects of the battery management system provided by the present invention, please refer to the above description of the beneficial effects of the relay fault detection device provided by the present invention, and no further details will be given here.

[0110] Preferably, in one exemplary embodiment, see Figure 5 , Figure 5 Figure 5 The block diagram of the battery management system provided in this embodiment. Figure 5 It can be seen that the battery management system provided in this embodiment also includes a main controller 210 and at least two slave controllers 220, the main controller 210 and the slave controllers 220 are connected in a daisy chain manner; the main controller 210 is used to control the on / off state of the relay to perform battery pack cutting; the slave controller 220 is used to obtain the cell voltage of the battery pack corresponding to the slave controller 220 and the temperature of each battery module in each battery pack. Preferably, the performance of the battery management system can be further improved.

[0111] Embodiment 4

[0112] Based on the same inventive concept, this embodiment provides a readable storage medium, in which a computer program is stored. When the computer program is executed by a processor, the relay fault detection method described in any of the above embodiments is implemented. Since the readable storage medium provided by the present invention and the relay fault detection method provided by the present invention belong to the same inventive concept, the readable storage medium provided by the present invention at least has all the advantages of the relay fault detection method provided by the present invention. For details of the beneficial effects of the readable storage medium provided by the present invention, please refer to the above description of the beneficial effects of the relay fault detection method provided by the present invention, which will not be repeated here.

[0113] The readable storage medium of the embodiment of the present invention can adopt any combination of one or more computer-readable media. The readable medium can be a computer-readable signal medium or a computer-readable storage medium. The computer-readable storage medium can be, for example, but not limited to, a system, device or device of electricity, magnetism, light, electromagnetic, infrared or semiconductor, or any combination of the above. More specific examples (non-exhaustive examples) of computer-readable storage media include: an electrical connection with one or more wires, a portable computer hard disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In this article, a computer-readable storage medium can be any tangible medium containing or storing a program, which can be used by an instruction execution system, a device or a device or used in combination with it.

[0114] Computer-readable signal media may include data signals propagated in baseband or as part of a carrier wave, which carry computer-readable program code. Such propagated data signals may take a variety of forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination of the above. Computer-readable signal media may also be any computer-readable medium other than a computer-readable storage medium, which may send, propagate, or transmit a program for use by or in conjunction with an instruction execution system, apparatus, or device.

[0115] Computer program code for performing the operation of the present invention may be written in one or more programming languages ​​or a combination thereof, including object-oriented programming languages ​​such as Java, Smalltalk, C++, and conventional procedural programming languages ​​such as "C" or similar programming languages. The program code may be executed entirely on the user's computer, partially on the user's computer, as a separate software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In the case of a remote computer, the remote computer may be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computer (e.g., via the Internet using an Internet service provider).

[0116] Compared with the prior art, the relay fault detection method, device, battery management system and medium provided by the present invention have the following advantages:

[0117] The relay fault detection method provided by the present invention, the relay fault detection method provided by the present invention, first obtains the current charging scheme and the current charging electrical stage, and the charging electrical stage includes the upper high-voltage charging pre-stage, the upper high-voltage charging stage and the charging completion stage. Thus, a solid foundation is laid for determining the relay to be detected for different charging schemes and different charging stages. Then, in each of the charging electrical stages, the relay to be detected corresponding to the current charging electrical stage is determined according to the current charging scheme and the circuit topology relationship between the battery pack and the relay. Thus, the leakage detection of the relay during the battery pack cutting process can be avoided, so that the detection coverage can be guaranteed. Finally, for each of the relays to be detected, the detection voltage values ​​at both ends of the relay to be detected are obtained according to the circuit topology relationship; and the fault detection result of the relay to be detected is obtained according to the detection voltage value and the expected voltage value of the relay to be detected in the current charging electrical stage. Thus, the present invention can improve the diagnostic robustness of the battery management system and reduce false fault alarms under the premise of meeting the diagnostic coverage of functional safety voltage sampling ASIL C; and can accurately locate the position of the virtual connection sampling line, reduce the difficulty of troubleshooting, and save manpower and material costs.

[0118] Since the relay fault detection device, battery management system and medium provided by the present invention belong to the same inventive concept as the relay fault detection method provided by the present invention, the relay fault detection device, battery management system and medium provided by the present invention at least have all the advantages of the relay fault detection method provided by the present invention. For details about the beneficial effects of the relay fault detection device, battery management system and medium provided by the present invention, please refer to the above description of the beneficial effects of the relay fault detection method provided by the present invention, and no further details will be given here.

[0119] It should be noted that the devices and methods disclosed in the embodiments of this article can also be implemented in other ways. The device implementation described above is only schematic. For example, the flowcharts and block diagrams in the accompanying drawings show the possible architecture, functions and operations of the devices, methods and computer program products according to multiple embodiments of this article. In this regard, each box in the flowchart or block diagram can represent a part of a module, program or code, and the module, program segment or part of the code contains one or more executable instructions for implementing the specified logical function, and the module, program segment or part of the code contains one or more executable instructions for implementing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in a different order from the order marked in the accompanying drawings. For example, two consecutive boxes can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram and / or flowchart, and the combination of boxes in the block diagram and / or flowchart can be implemented by a dedicated hardware-based system for performing a specified function or action, or can be implemented by a combination of dedicated hardware and computer instructions.

[0120] In addition, the functional modules in the various embodiments of this document may be integrated together to form an independent part, or each module may exist independently, or two or more modules may be integrated to form an independent part.

[0121] The above description is only a description of a preferred embodiment of a relay fault detection method, device, battery management system and medium provided by the present invention, and is not any limitation on the scope of the present invention. Any changes and modifications made by ordinary technicians in the field of the present invention based on the above disclosure content belong to the protection scope of the present invention. Obviously, technicians in this field can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations fall within the scope of the present invention and its equivalent technology, the present invention is also intended to include these modifications and variations.

Claims

1. A relay fault detection method, characterized in that: The method is used to detect whether the relay is faulty when the battery management system controls the relay to be turned on and / or off to perform battery pack switching. The relay fault detection method includes: Obtaining the current charging scheme and the current charging electrical stage; the charging electrical stage includes the upper high-voltage charging pre-stage, the upper high-voltage charging stage, and the charging completion stage; In each of the charging electrical phases, the following operations are performed: Determine the relay to be detected corresponding to the current charging electrical stage according to the current charging scheme and the circuit topology relationship between the battery pack and the relay; For each of the relays to be detected, the detection voltage values ​​at both ends of the relay to be detected are obtained according to the circuit topology relationship; and the fault detection result of the relay to be detected is obtained according to the detection voltage value and the expected voltage value of the relay to be detected in the current charging electrical stage.

2. The relay fault detection method according to claim 1, characterized in that: The relay fault detection method further comprises: Determining the current charging scheme according to the battery pack cutting instruction of the battery management system; The current electrical charging stage is determined according to the current charging scheme and the relay switch control instruction of the battery management system.

3. The relay fault detection method according to claim 1, characterized in that: The circuit topology of the battery pack-relay includes two relays for connecting the positive charging electrode and the negative charging electrode, respectively, and at least three relays for connecting the battery pack; the on and / or off states of the at least three relays for connecting the battery pack are used to change the connection state between the battery packs to achieve at least two different charging schemes; The step of determining the relay to be detected corresponding to the current charging electrical stage according to the current charging scheme and the circuit topology relationship between the battery pack and the relay includes: In the pre-high voltage charging stage, the relay used to connect the battery pack is used as the relay to be detected; In the upper high-voltage charging stage and the charging completion stage, the relay used to connect the charging positive electrode and the charging negative electrode, and the relay used to connect the battery pack that is in a conductive state during the charging process of the current charging scheme are used as the relays to be detected.

4. The relay fault detection method according to claim 1, characterized in that: The method of obtaining a fault detection result of the relay to be detected according to the detection voltage value and the expected voltage value of the relay to be detected in the current charging electrical stage includes: If the current charging electrical stage is the upper high-voltage charging pre-stage or the charging completion stage, it is determined whether the absolute value of the difference between the detection voltage value and the expected voltage value is less than a first preset value, and if so, the relay to be detected has a sticking fault; If the current charging electrical stage is the upper high-voltage charging stage, it is determined whether the absolute value of the difference between the detected voltage value and the expected voltage value is greater than a second preset value. If so, the relay to be detected has a stuck fault.

5. A relay fault detection device, characterized in that: The relay fault detection device is used to detect whether the relay is faulty when the battery management system controls the relay to be turned on and / or off to perform battery pack switching. The relay fault detection device includes: A charging scheme and charging stage acquisition unit is configured to acquire the current charging scheme and the current charging electrical stage; the charging electrical stage includes a stage before upper high-voltage charging, an upper high-voltage charging stage, and a charging completion stage; The fault detection execution unit is configured to perform the following operations in each of the charging electrical stages: Determine the relay to be detected corresponding to the current charging electrical stage according to the current charging scheme and the circuit topology relationship between the battery pack and the relay; For each of the relays to be detected, the detection voltage values ​​at both ends of the relay to be detected are obtained according to the circuit topology relationship; and the fault detection result of the relay to be detected is obtained according to the detection voltage value and the expected voltage value of the relay to be detected in the current charging electrical stage.

6. The relay fault detection device according to claim 5, characterized in that: The circuit topology of the battery pack-relay includes a first battery pack, a second battery pack, a first relay, a second relay, a third relay, a fourth relay and a fifth relay; the fault detection execution unit includes a first voltage detection unit, a second voltage detection unit, a third voltage detection unit, a fourth voltage detection unit and a fifth voltage detection unit for obtaining the detection voltage value; the first end of the first battery pack, the first end of the first relay and the first end of the second relay are coupled to a first node, and the first voltage detection unit is set at the first node; the second end of the second relay, the first end of the second battery pack and the first end of the third relay are coupled to a second node, and the second voltage detection unit is set at the second node; the second end of the first relay, the second end of the second battery pack and the first end of the fourth relay are coupled to a third node, and the third voltage detection unit is set at the third node; the second end of the fourth relay is coupled to the positive charging electrode at a fourth node, and the fourth voltage detection unit is set at the fourth node; the second end of the first battery pack and the second end of the third relay are coupled to the first end of the fifth relay, the second end of the fifth relay is coupled to the negative charging electrode at a fifth node, and the fifth voltage detection unit is set at the fifth node.

7. The relay fault detection device according to claim 6, characterized in that: The circuit topology relationship of the battery pack-relay is configured to implement a first voltage charging scheme when the first relay is turned on, the third relay is turned on, and the second relay is turned off; and implement a second voltage charging scheme when the first relay is turned off, the third relay is turned off, and the second relay is turned on; The fault detection execution unit is configured to obtain, for each of the relays to be detected, a detection voltage value at both ends of the relay to be detected according to the circuit topology relationship, including: Acquire detection voltage values ​​at both ends of the first relay and / or the third relay according to the voltage values ​​collected by the first voltage detection unit and the third voltage detection unit; Acquire detection voltage values ​​at both ends of the second relay according to the voltage values ​​collected by the first voltage detection unit and the second voltage detection unit; Acquire detection voltage values ​​at both ends of the fourth relay according to the voltage values ​​collected by the first voltage detection unit and the fourth voltage detection unit; The detection voltage value of the fifth relay is obtained according to the voltage value collected by the fourth voltage detection unit to detect whether the fifth relay has a sticking fault; the detection voltage value of the fifth relay is obtained according to the voltage values ​​collected by the fourth voltage detection unit and the fifth voltage detection unit to detect whether the fifth relay has a adhesion fault.

8. A battery management system, characterized in that: It comprises a relay fault detection device as claimed in any one of claims 5 to 7.

9. The battery management system according to claim 8, characterized in that: It also includes a main controller and at least two slave controllers, the main controller and the slave controllers are connected in a daisy chain manner; the main controller is used to control the on / off state of the relay to perform battery pack cutting; the slave controller is used to obtain the cell voltage of the battery pack corresponding to the slave controller and the temperature of each battery module in each battery pack.

10. A readable storage medium, characterized in that: The readable storage medium stores a computer program, and when the computer program is executed by a processor, the relay fault detection method according to any one of claims 1 to 4 is implemented.

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