Electric leakage detection system, electrical assembly and vehicle

Abstract

The application relates to an electric leakage detection system, an electric assembly and a vehicle, which are used for electric leakage detection of a power system in the vehicle, the power system comprising a battery pack, a plurality of loads and a power supply circuit electrically connected with the battery pack and the plurality of loads respectively; the electric leakage detection system comprises a plurality of circuit switch units and a plurality of first electric leakage detection units; the circuit switch unit is used for being electrically connected with the power supply circuit and a corresponding load and controlling the on-off between the power supply circuit and the load; the first electric leakage detection unit is used for being electrically connected with the corresponding load and detecting a first electric leakage result of the load after the load is disconnected from the power supply circuit. The electric leakage detection system in the application sets the corresponding circuit switch unit and the first electric leakage detection unit for each load, in the running process of the vehicle, any load can be disconnected from the power supply circuit and the electric leakage detection of the load is carried out, so that the electric leakage detection of the load can be realized without affecting the running of other loads.

Description

Technical Field

[0001] This application relates to the field of electrical safety technology, and in particular to a leakage current detection system, an electrical assembly, and a vehicle. Background Technology

[0002] With the continuous development of the automotive industry, the number of electric vehicles on the road is increasing, and the voltage level of the high-voltage platform of the vehicle is also constantly increasing. The high-voltage loads involved in electric vehicles include air conditioning, drive system, OBC (on-board charger), and DC-DC (direct current converter), etc., and these high-voltage loads all involve high-voltage insulation issues.

[0003] With the continuous use of high-voltage loads, changes in working conditions, vibration, temperature, and humidity may cause insulation aging in the high-voltage loads, leading to a reduction in the overall vehicle insulation performance and affecting the normal operation of the high-voltage loads. Leakage caused by insulation aging can also endanger the personal safety of the driver.

[0004] During vehicle operation, existing technologies can typically only perform overall leakage detection on the power supply circuits connecting the battery pack and each high-voltage load. Utility Model Content

[0005] This application provides a leakage current detection system, an electrical assembly, and a vehicle. For each load, a corresponding circuit switch unit and a first leakage current detection unit are set. During the operation of the vehicle, any load can be disconnected from the power supply circuit and leakage current detection can be performed on that load. This achieves leakage current detection of a certain load without affecting the operation of other loads, thereby at least partially solving the above-mentioned technical problems.

[0006] To achieve the above objectives, according to a first aspect of this application, a leakage current detection system is provided for detecting leakage current in a power system of a vehicle. The power system includes a battery pack, multiple loads, and power supply circuits electrically connected to the battery pack and the multiple loads respectively. The leakage current detection system includes multiple circuit switching units and multiple first leakage current detection units. The circuit switch unit is used to electrically connect to the power supply circuit and the corresponding load, and to control the on / off connection between the power supply circuit and the load. The first leakage current detection unit is used to electrically connect to the corresponding load and detect the first leakage current result of the load after the load is disconnected from the power supply circuit.

[0007] Optionally, the circuit switch unit includes a positive circuit switch and a negative circuit switch; The positive circuit switch is used to electrically connect to the positive terminal of the power supply circuit and the corresponding positive terminal of the load, while the negative circuit switch is used to electrically connect to the negative terminal of the power supply circuit and the corresponding negative terminal of the load.

[0008] Optionally, the first leakage detection unit is used to electrically connect to the positive and negative terminals of the corresponding load and detect the first positive leakage result and the first negative leakage result of the load after the load is disconnected from the power supply circuit. The first leakage result includes the first positive leakage result and the first negative leakage result.

[0009] Optionally, the first leakage current detection unit includes a detection power supply, a first resistor, a second resistor, a third resistor, and a first switching switch; The positive terminal of the detection power supply is electrically connected to the first end of the first resistor and is used to connect to the positive terminal of the corresponding load. The second end of the first resistor is electrically connected to the first end of the first switch and the first end of the second resistor. The second end of the second resistor and the first end of the third resistor are used to ground. The second end of the third resistor and the second end of the first switch are electrically connected to the negative terminal of the detection power supply. The negative terminal of the detection power supply is used to connect to the negative terminal of the corresponding load. The voltage across the third resistor represents the first leakage current result of the corresponding load.

[0010] Optionally, each first leakage current detection unit shares a detection power supply, a first resistor, a second resistor, a third resistor, and a first switching switch; the first leakage current detection unit also includes a positive control switch and a negative control switch; The positive control switch is electrically connected to the positive terminal of the detection power supply and the corresponding positive terminal of the load, while the negative control switch is electrically connected to the negative terminal of the detection power supply and the corresponding negative terminal of the load.

[0011] Optionally, the leakage current detection system may also include a second leakage current detection unit; The second leakage current detection unit is used to be electrically connected to the power supply circuit and to detect the second leakage current result of the power supply circuit.

[0012] Optionally, the second leakage detection unit is electrically connected to the positive and negative terminals of the power supply circuit respectively and detects the second positive leakage result and the second negative leakage result of the power supply circuit. The second leakage result includes the second positive leakage result and the second negative leakage result.

[0013] Optionally, the second leakage detection unit includes a fourth resistor, a fifth resistor, a sixth resistor, and a second switching switch; The first end of the fourth resistor is used to connect to the positive terminal of the power supply circuit. The second end of the fourth resistor is connected to the first end of the second switch and the first end of the fifth resistor. The second end of the fifth resistor and the first end of the sixth resistor are used to ground. The second end of the sixth resistor and the second end of the second switch are used to connect to the negative terminal of the power supply circuit. The voltage across the sixth resistor characterizes the second leakage result.

[0014] According to a second aspect of this application, an electrical assembly is provided, including the leakage current detection system in any of the above embodiments.

[0015] According to a third aspect of this application, a vehicle is provided that includes the leakage current detection system of any of the above embodiments, or includes the electrical assembly of any of the above embodiments.

[0016] The leakage current detection system in this application sets up a corresponding circuit switch unit and a first leakage current detection unit for each load. During the operation of the vehicle, it can disconnect any load from the power supply circuit and perform leakage current detection on that load, thereby realizing leakage current detection of a certain load without affecting the operation of other loads.

[0017] Other features and advantages of this application will be described in detail in the following detailed description section. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] To gain a more complete understanding of this application and its beneficial effects, the following description will be provided in conjunction with the accompanying drawings, wherein the same reference numerals in the following description denote the same parts.

[0020] Figure 1 This is a schematic diagram of the leakage current detection system and power system provided in an exemplary embodiment of this application; Figure 2 This is a schematic diagram of the structure of the leakage current detection system provided in the exemplary embodiment of this application, which also includes a second leakage current detection unit; Figure 3 This is a schematic diagram showing various specific types of loads provided in an exemplary embodiment of this application; Figure 4 This is a schematic diagram of the structure of the first leakage current detection unit provided in an exemplary embodiment of this application; Figure 5 This is provided in an exemplary embodiment of this application. Figure 4 Equivalent schematic diagram when the first switching switch is in the off state; Figure 6 This is provided in an exemplary embodiment of this application. Figure 4 Equivalent schematic diagram when the first switching switch is in the ON state; Figure 7This is a schematic diagram of the structure of each first leakage current detection unit in the exemplary embodiment of this application when a common device is used; Figure 8 This is a schematic diagram of the structure of the second leakage current detection unit provided in an exemplary embodiment of this application. Detailed Implementation

[0021] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the protection scope of this application.

[0022] According to the first aspect of this application, Figure 1 As shown, a leakage current detection system is provided for detecting leakage current in the power system of a vehicle. The power system includes a battery pack, multiple loads, and power supply circuits electrically connected to the battery pack and the multiple loads respectively. The leakage current detection system includes multiple circuit switching units and multiple first leakage current detection units.

[0023] Among them, the power supply circuit is Figure 1 The battery pack includes a positive terminal and a negative terminal, with the positive terminal represented by a thick red solid line and the negative terminal represented by a thick black solid line. The positive terminal of the battery pack is electrically connected to the positive terminal of the power supply circuit, and the negative terminal of the battery pack is electrically connected to the negative terminal of the power supply circuit. The positive and negative terminals of the power supply circuit are electrically connected to the positive and negative terminals of the corresponding loads through a circuit switching unit.

[0024] The battery pack can discharge to the corresponding load via the power supply circuit, enabling the load to perform its function based on the power provided by the battery pack; in this state, the battery pack is in a discharging state. Conversely, the corresponding load can also charge the battery pack via the power supply circuit, allowing the battery pack to replenish its power based on the power provided by the load; in this state, the battery pack is in a charging state. In other words, the power supply circuit is not limited to discharging the battery pack; it can also charge it. Furthermore, the load electrically connected to the power supply load is not limited to consuming the battery pack's power; it can also replenish the battery pack's power.

[0025] The circuit switch unit is used to electrically connect to the power supply circuit and the corresponding load and to control the on / off state between the power supply circuit and the load.

[0026] As mentioned above, the power supply circuit includes a positive and a negative terminal and is electrically connected to the positive and negative terminals of the corresponding load through a circuit switch unit. It can be understood that when the positive terminal of the power supply circuit and the positive terminal of the load are disconnected, the power supply circuit and the load are in a disconnected state, so that the load can no longer transfer electrical energy to the power supply circuit. Therefore, the circuit switch unit can only be used to control the connection and disconnection between the positive terminal of the power supply circuit and the positive terminal of the corresponding load.

[0027] The first leakage current detection unit is used to electrically connect to the corresponding load and detect the first leakage current result of the load after the load is disconnected from the power supply circuit.

[0028] The first leakage detection unit typically detects leakage by measuring the insulation resistance between the load and ground. If the insulation resistance is lower than a target value for the load, leakage is considered present; otherwise, if the insulation resistance is above the target value, leakage is not considered. However, when the load is connected to the power supply circuit, it is connected in parallel with other loads connected to the power supply circuit. This means the actual insulation resistance of the load is the parallel resistance of all loads connected to the power supply circuit, making leakage detection impossible. Therefore, in this embodiment, a circuit breaker unit is added. When leakage detection is needed, the corresponding circuit breaker unit is disconnected, disconnecting the load from the power supply circuit. The detected insulation resistance is the load's own insulation resistance, thus achieving leakage detection.

[0029] It is understandable that when the load is disconnected from the power supply circuit, it can no longer obtain power from the power supply circuit, so there is no possibility of leakage. Therefore, the first leakage result is to characterize whether the load has a leakage problem, rather than whether the load is currently leaking.

[0030] Specifically, a circuit breaker unit can be used to disconnect loads that are not currently in operation from the power supply circuit. For a specific load: When the first leakage detection unit detects a first leakage result indicating that the load has no leakage problem (i.e., the corresponding insulation resistance value is not lower than the corresponding target value), the load is considered to have no leakage risk. Subsequently, when the load needs to operate, it can be connected to the power supply circuit through the corresponding circuit switch unit.

[0031] When the first leakage detection unit detects a leakage result indicating that the load has a leakage problem (i.e., the corresponding insulation resistance value is lower than the corresponding target value), it considers the load to have a leakage risk and issues an alarm. Subsequently, when the load needs to operate, it is still disconnected from the power supply circuit through the corresponding circuit switch unit.

[0032] The leakage current detection system in this application sets up a corresponding circuit switch unit and a first leakage current detection unit for each load. During the operation of the vehicle, it can disconnect any load from the power supply circuit and perform leakage current detection on that load, thereby realizing leakage current detection of a certain load without affecting the operation of other loads.

[0033] like Figure 2 As shown, optionally, the leakage current detection system may also include a second leakage current detection unit.

[0034] The second leakage current detection unit is used to be electrically connected to the power supply circuit and to detect the second leakage current result of the power supply circuit.

[0035] Similar to the first leakage detection unit in the above embodiment, the second leakage detection unit also typically detects leakage in the power supply circuit by detecting the insulation resistance between the power supply circuit and ground. When the insulation resistance is lower than the target value corresponding to the power supply circuit, it is considered that there is a leakage problem in the power supply circuit; conversely, when the insulation resistance is not lower than the target value corresponding to the power supply circuit, it is considered that there is no leakage problem in the power supply circuit.

[0036] It should be noted that since the power supply circuit is electrically connected to the load, the second leakage result of the power supply circuit is actually the leakage result of all loads connected to the power supply circuit. When the second leakage result indicates that there is a leakage problem in the power supply circuit, it means that at least one of the loads connected to the power supply circuit has a leakage problem. When the second leakage result indicates that there is no leakage problem in the power supply circuit, it means that no load has a leakage problem among all the loads connected to the power supply circuit.

[0037] Based on the above analysis, in practical applications, the power supply circuit can be detected as a whole by the second leakage detection unit. If a leakage problem is found, the first leakage detection unit can be used to detect the leakage of each load individually, thereby locating the load with the leakage problem. Conversely, if there is no leakage problem, it is not necessary to use the first leakage detection unit to locate the load with the leakage problem.

[0038] Optionally, a second leakage detection unit and each circuit switching unit can be used to locate the load with leakage problems. In this embodiment, the multiple loads can be the air conditioner, OBC, DC-DC converter, and drive assembly. This is provided that the air conditioner, OBC, DC-DC converter, and drive assembly are all connected to the power supply circuit: When the second leakage detection unit detects that the second leakage result of the power supply circuit indicates that there is no leakage problem in the power supply circuit (i.e., the corresponding insulation resistance value is not lower than the corresponding target value), it is considered that the air conditioner, OBC, DCDC and drive assembly are working normally and there is no risk of leakage, and the switching units of each circuit can be kept in the conducting state.

[0039] When the second leakage detection unit detects a second leakage result in the power supply circuit indicating a leakage problem (i.e., the corresponding insulation resistance value is lower than the corresponding target value), it considers at least one of the air conditioner, OBC, DC-DC, and drive assembly to have a leakage risk and issues an alarm. According to priority, each load is disconnected from the power supply circuit sequentially through each circuit switching unit until the second leakage detection unit detects a second leakage result in the power supply circuit indicating no leakage problem. Then, the last disconnected load can be identified as the load with a leakage problem.

[0040] Specifically, during charging, the priority for disconnecting from the power supply circuit is OBC > DC-DC > drive assembly > air conditioning; during discharging, the priority for disconnecting from the power supply circuit is drive assembly > DC-DC > OBC > air conditioning.

[0041] Optionally, the loop switch unit includes a positive loop switch and a negative loop switch.

[0042] The positive circuit switch is used to electrically connect to the positive terminal of the power supply circuit and the corresponding positive terminal of the load, while the negative circuit switch is used to electrically connect to the negative terminal of the power supply circuit and the corresponding negative terminal of the load.

[0043] Specifically, such as Figure 3 As shown, the multiple loads can be air conditioning, OBC, DC-DC and drive assembly, and the drive assembly further includes a motor controller and a transmission.

[0044] The power system also includes a positive battery switch K1 and a negative battery switch K2. The positive terminal of the battery pack is electrically connected to the positive terminal of the power supply circuit through the positive battery switch K1, and the negative terminal of the battery pack is electrically connected to the negative terminal of the power supply circuit through the negative battery switch K2.

[0045] The positive terminal of the air conditioner is electrically connected to the positive terminal of the power supply circuit through the positive terminal circuit switch K3, and the negative terminal of the air conditioner is electrically connected to the negative terminal of the power supply circuit through the negative terminal circuit switch K4.

[0046] The positive terminal of the OBC is electrically connected to the positive terminal of the power supply circuit through the positive terminal circuit switch K5, and the negative terminal of the OBC is electrically connected to the negative terminal of the power supply circuit through the negative terminal circuit switch K6.

[0047] The positive terminal of the DC-DC converter is electrically connected to the positive terminal of the power supply circuit through the positive terminal circuit switch K7, and the negative terminal of the DC-DC converter is electrically connected to the negative terminal of the power supply circuit through the negative terminal circuit switch K8.

[0048] The positive terminal of the motor controller in the drive assembly is electrically connected to the positive terminal of the power supply circuit through the positive terminal circuit switch K9, and the negative terminal of the motor controller in the drive assembly is electrically connected to the negative terminal of the power supply circuit through the negative terminal circuit switch K10.

[0049] Setting separate switches for the positive and negative terminals can improve the reliability of on / off control.

[0050] In this embodiment, the second leakage detection unit can be integrated into the vehicle's BMS (BATTERY MANAGEMENT SYSTEM), and the positive battery switch K1 and negative battery switch K2 can also be controlled by the BMS. Furthermore, the "positive circuit switch K3 and negative circuit switch K4", "positive circuit switch K5 and negative circuit switch K6", "positive circuit switch K7 and negative circuit switch K8", and "positive circuit switch K9 and negative circuit switch K10" can be controlled by their respective control units, or they can be controlled by the same control unit.

[0051] Among them, the positive battery switch K1, negative battery switch K2, positive circuit switch K3, negative circuit switch K4, positive circuit switch K5, negative circuit switch K6, positive circuit switch K7, negative circuit switch K8, positive circuit switch K9 and negative circuit switch K10 mentioned above can be in the form of relays or contactors.

[0052] Optionally, the first leakage detection unit is used to electrically connect to the positive and negative terminals of the corresponding load and detect the first positive leakage result and the first negative leakage result of the load after the load is disconnected from the power supply circuit. The first leakage result includes the first positive leakage result and the first negative leakage result.

[0053] Specifically, such as Figure 3 As shown, the first leakage detection unit corresponding to the air conditioner is electrically connected to the positive and negative terminals of the air conditioner, the first leakage detection unit corresponding to the OBC is electrically connected to the positive and negative terminals of the OBC, the first leakage detection unit corresponding to the DC-DC converter is electrically connected to the positive and negative terminals of the DC-DC converter, and the first leakage detection unit corresponding to the drive assembly is electrically connected to the positive and negative terminals of the motor controller in the drive assembly.

[0054] Leakage detection is performed on both the positive and negative terminals of the load separately, which improves the comprehensiveness of leakage detection.

[0055] like Figure 4 As shown, optionally, the first leakage current detection unit includes a detection power supply, a first resistor R1, a second resistor R2, a third resistor R3, and a first switching switch Kb.

[0056] The positive terminal of the detection power supply is electrically connected to the first end of the first resistor R1. The second end of the first resistor R1 is electrically connected to the first end of the first switch Kb and the first end of the second resistor R2. The second end of the second resistor R2 and the first end of the third resistor R3 are respectively used for grounding. The second end of the third resistor R3 and the second end of the first switch Kb are respectively electrically connected to the negative terminal of the detection power supply. The negative terminal of the detection power supply is used to connect to the negative terminal of the corresponding load.

[0057] The positive terminal of the detection power supply is used to connect electrically to the positive terminal of the corresponding load. The insulation between the positive terminal of the load and ground can be represented as the positive insulation resistance Rn+. The negative terminal of the detection power supply is used to connect electrically to the negative terminal of the corresponding load. The insulation between the negative terminal of the load and ground can be represented as the negative insulation resistance Rn-.

[0058] The voltage across the third resistor R3 represents the first leakage current result of the corresponding load.

[0059] Among them, based on the different switching states of the first switching switch Kb, the terminal voltage of the third resistor R3 has different values, so the positive insulation resistance Rn+ (which can be understood as the first positive leakage detection result) and the negative insulation resistance Rn- (which can be understood as the first negative leakage detection result) can be determined based on the terminal voltage of the third resistor R3.

[0060] Specifically, when the first switching switch Kb is in the off state, Figure 4 The circuit shown can be equivalent to Figure 5 Based on the current consistency, the circuit shown in the figure can be used to derive: (1) Where Up is the voltage of the detection power supply, and U1 is the terminal voltage of the third resistor R3 when the first switching switch Kb is in the open state.

[0061] When the first switching switch Kb is in the ON state Figure 4 The circuit shown can be equivalent to Figure 6 Based on the current consistency, the circuit shown in the figure can be used to derive: (2) Wherein, U2 is the terminal voltage of the third resistor R3 when the first switching switch Kb is in the on state.

[0062] Combining formulas (1) and (2), all quantities except the positive insulation resistance Rn+ and the negative insulation resistance Rn- are known, so the positive insulation resistance Rn+ and the negative insulation resistance Rn- can be obtained, and then the corresponding first positive leakage current result and the first negative leakage current result can be obtained.

[0063] Optionally, each first leakage current detection unit shares a detection power supply, a first resistor, a second resistor, a third resistor, and a first switching switch; the first leakage current detection unit also includes a positive control switch and a negative control switch.

[0064] The positive control switch is electrically connected to the positive terminal of the detection power supply and the corresponding positive terminal of the load, while the negative control switch is electrically connected to the negative terminal of the detection power supply and the corresponding negative terminal of the load.

[0065] Since the detection principle of each first leakage current detection unit is the same and the required components are also the same, the components used can be shared to improve the system integration.

[0066] It should be noted that when shared components are used, the loads will be connected in parallel, making it impossible to detect leakage current in a single load. Therefore, in this embodiment, additional positive and negative control switches are provided for each load to address this issue. When leakage current detection is required for a certain load, the corresponding positive and negative control switches are turned on.

[0067] Specifically, such as Figure 7 As shown, the first leakage detection unit corresponding to the air conditioner includes a positive control switch S3 and a negative control switch S4; the first leakage detection unit corresponding to the OBC includes a positive control switch S5 and a negative control switch S6; the first leakage detection unit corresponding to the DC-DC converter includes a positive control switch S7 and a negative control switch S8; and the first leakage detection unit corresponding to the drive assembly includes a positive control switch S9 and a negative control switch S10.

[0068] The positive terminal of the detection power supply is used to connect to the positive terminal of the air conditioner via the positive control switch S3. The insulation between the positive terminal of the air conditioner and ground can be represented as the positive insulation resistance Ra+. The negative terminal of the detection power supply is used to connect to the negative terminal of the air conditioner via the negative control switch S4. The insulation between the negative terminal of the air conditioner and ground can be represented as the negative insulation resistance Ra-.

[0069] The positive terminal of the detection power supply is used to connect to the positive terminal of the OBC via the positive control switch S5. The insulation between the positive terminal of the OBC and ground can be represented as the positive insulation resistance Ro+. The negative terminal of the detection power supply is used to connect to the negative terminal of the OBC via the negative control switch S6. The insulation between the negative terminal of the OBC and ground can be represented as the negative insulation resistance Ro-.

[0070] The positive terminal of the detection power supply is used to connect to the positive terminal of the DC-DC converter via the positive control switch S7. The insulation between the positive terminal of the DC-DC converter and ground can be represented as the positive insulation resistance Rd+. The negative terminal of the detection power supply is used to connect to the negative terminal of the DC-DC converter via the negative control switch S8. The insulation between the negative terminal of the DC-DC converter and ground can be represented as the negative insulation resistance Rd-.

[0071] The positive terminal of the detection power supply is used to electrically connect to the positive terminal of the drive assembly through the positive control switch S9. The insulation between the positive terminal of the drive assembly and ground can be expressed as the positive insulation resistance Rm+. The negative terminal of the detection power supply is used to electrically connect to the negative terminal of the drive assembly through the negative control switch S10. The insulation between the negative terminal of the drive assembly and ground can be expressed as the negative insulation resistance Rm-.

[0072] The leakage current detection of the air conditioner, OBC, DC-DC converter, and drive assembly can be referred to the above embodiments, and will not be repeated here.

[0073] Optionally, the second leakage detection unit is electrically connected to the positive and negative terminals of the power supply circuit respectively and detects the second positive leakage result and the second negative leakage result of the power supply circuit. The second leakage result includes the second positive leakage result and the second negative leakage result.

[0074] Similar to the first leakage detection unit, the second leakage detection unit performs leakage detection on the positive and negative terminals of the power supply circuit, thereby improving the comprehensiveness of leakage detection.

[0075] like Figure 8 As shown, optionally, the second leakage detection unit includes a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, and a second switching switch Ks.

[0076] The first end of the fourth resistor R4 is used to connect to the positive terminal of the power supply circuit (i.e., to the positive terminal of the battery pack via the positive battery switch K1). The second end of the fourth resistor R4 is connected to the first end of the second switching switch Ks and the first end of the fifth resistor R5. The second end of the fifth resistor R5 and the first end of the sixth resistor R6 are used to ground. The second end of the sixth resistor R6 and the second end of the second switching switch Ks are used to connect to the negative terminal of the power supply circuit (i.e., to the negative terminal of the battery pack via the negative battery switch K2).

[0077] The insulation between the positive terminal of the power supply circuit and ground can be represented as the positive insulation resistance R+, and the insulation between the negative terminal of the power supply circuit and ground can be represented as the negative insulation resistance R-.

[0078] The voltage across the sixth resistor R6 characterizes the second leakage current result.

[0079] Based on the different switching states of the second switching switch Ks, the terminal voltage of the sixth resistor R6 has different values, so the positive insulation resistance R+ (which can be understood as the second positive leakage detection result) and the negative insulation resistance R- (which can be understood as the second negative leakage detection result) can be determined based on the terminal voltage of the sixth resistor R3.

[0080] The specific principle of the second leakage current detection unit can be referred to the first leakage current detection unit mentioned above, and will not be repeated here.

[0081] According to a second aspect of this application, an electrical assembly is provided, including the leakage current detection system in any of the above embodiments.

[0082] The leakage detection system included in the electrical assembly of this application is equipped with a corresponding circuit switch unit and a first leakage detection unit for each load. During the operation of the vehicle, any load can be disconnected from the power supply circuit and leakage detection can be performed on that load, thereby realizing leakage detection of a certain load without affecting the operation of other loads.

[0083] According to a third aspect of this application, a vehicle is provided that includes the leakage current detection system of any of the above embodiments, or includes the electrical assembly of any of the above embodiments.

[0084] The leakage detection system included in the vehicle of this application is equipped with a corresponding circuit switch unit and a first leakage detection unit for each load. During the operation of the vehicle, any load can be disconnected from the power supply circuit and leakage detection can be performed on that load, thereby realizing leakage detection of a certain load without affecting the operation of other loads.

[0085] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more features. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0086] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0087] The embodiments, implementation methods, and related technical features of this application can be combined and substituted for each other without conflict.

[0088] The above are merely preferred embodiments of this application and are not intended to limit this application in any way. In the embodiments of this application, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant content of other embodiments. Any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of this application without departing from the content of the technical solution of this application shall still fall within the scope of the technical solution of this application.

Claims

1. A leakage current detection system, characterized in that, For detecting leakage current in the power system of a vehicle, the power system includes a battery pack, multiple loads, and power supply circuits electrically connected to the battery pack and the multiple loads respectively; the leakage current detection system includes multiple circuit switching units and multiple first leakage current detection units. The circuit switch unit is used to electrically connect to the power supply circuit and the corresponding load, and to control the on / off connection between the power supply circuit and the load. The first leakage current detection unit is used to be electrically connected to the corresponding load and to detect the first leakage current result of the load after the load is disconnected from the power supply circuit.

2. The leakage current detection system according to claim 1, characterized in that, The circuit switch unit includes a positive circuit switch and a negative circuit switch; The positive circuit switch is used to electrically connect to the positive terminal of the power supply circuit and the positive terminal of the corresponding load, and the negative circuit switch is used to electrically connect to the negative terminal of the power supply circuit and the negative terminal of the corresponding load.

3. The leakage current detection system according to claim 2, characterized in that, The first leakage detection unit is used to electrically connect to the positive and negative terminals of the corresponding load and detect the first positive leakage result and the first negative leakage result of the load after the load is disconnected from the power supply circuit. The first leakage result includes the first positive leakage result and the first negative leakage result.

4. The leakage current detection system according to claim 3, characterized in that, The first leakage current detection unit includes a detection power supply, a first resistor, a second resistor, a third resistor, and a first switching switch; The positive terminal of the detection power supply is electrically connected to the first end of the first resistor and is used to connect to the positive terminal of the corresponding load. The second end of the first resistor is electrically connected to the first end of the first switch and the first end of the second resistor. The second end of the second resistor and the first end of the third resistor are used to ground. The second end of the third resistor and the second end of the first switch are electrically connected to the negative terminal of the detection power supply. The negative terminal of the detection power supply is used to connect to the negative terminal of the corresponding load. The terminal voltage of the third resistor characterizes the first leakage current result of the corresponding load.

5. The leakage current detection system according to claim 4, characterized in that, Each of the first leakage current detection units shares the detection power supply, the first resistor, the second resistor, the third resistor, and the first switching switch; the first leakage current detection unit also includes a positive control switch and a negative control switch; The positive control switch is electrically connected to the positive terminal of the detection power supply and the positive terminal of the corresponding load, and the negative control switch is electrically connected to the negative terminal of the detection power supply and the negative terminal of the corresponding load.

6. The leakage current detection system according to any one of claims 1 to 5, characterized in that, The leakage current detection system also includes a second leakage current detection unit; The second leakage detection unit is used to be electrically connected to the power supply circuit and to detect the second leakage result of the power supply circuit.

7. The leakage current detection system according to claim 6, characterized in that, The second leakage detection unit is electrically connected to the positive and negative terminals of the power supply circuit and detects the second positive leakage result and the second negative leakage result of the power supply circuit. The second leakage result includes the second positive leakage result and the second negative leakage result.

8. The leakage current detection system according to claim 7, characterized in that, The second leakage detection unit includes a fourth resistor, a fifth resistor, a sixth resistor, and a second switching switch; The first end of the fourth resistor is used to be electrically connected to the positive terminal of the power supply circuit. The second end of the fourth resistor is electrically connected to the first end of the second switching switch and the first end of the fifth resistor, respectively. The second end of the fifth resistor and the first end of the sixth resistor are used to be grounded, respectively. The second end of the sixth resistor and the second end of the second switching switch are used to be electrically connected to the negative terminal of the power supply circuit. The terminal voltage of the sixth resistor characterizes the second leakage result.

9. An electrical assembly, characterized in that, Includes the leakage current detection system according to any one of claims 1 to 8.

10. A vehicle, characterized in that, It includes the leakage current detection system according to any one of claims 1 to 8, or the electrical assembly according to claim 9.

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