High-voltage sampling circuit, fault positioning circuit, electric equipment and fault positioning method

Abstract

The invention relates to a high-voltage sampling circuit, a fault positioning circuit, electric equipment and a fault positioning method. The high-voltage sampling circuit comprises a sampling driving circuit, a sampling feedback circuit and a voltage sampling circuit; a micro-control unit outside the high-voltage sampling circuit is respectively connected with the sampling driving circuit, the sampling feedback circuit and the voltage sampling circuit; the voltage sampling circuit is used for collecting voltage at one end of the relay; the sampling driving circuit is also respectively connected with one end of the relay and the sampling feedback circuit, and is used for conducting a high-voltage sampling loop according to the driving signal output by the micro-control unit; the sampling feedback circuit is also connected with the voltage sampling circuit and is used for outputting a self-checking signal to the micro-control unit; wherein the self-checking signal is used for representing whether the high-voltage sampling circuit is normal or not. According to the invention, the fault reason can be accurately positioned.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a high-voltage sampling circuit, a fault location circuit, an electrical device, and a fault location method. Background Art

[0002] With the development of new energy technologies, batteries are being used in an increasingly diverse range of applications. For example, new energy vehicles, intelligent robots, and drones are all powered by batteries. These battery packs typically include relays, a battery management system, and batteries. When the relay is on, the battery can power the load; when the relay is off, the battery stops supplying power.

[0003] Currently, when a relay fails to conduct, fault location is primarily based on the voltage across the relay. However, this method cannot distinguish whether the fault is a sampling circuit anomaly or a relay anomaly, resulting in inaccurate fault location. Summary of the Invention

[0004] Based on the above problems, the present application provides a high-voltage sampling circuit, a fault location circuit, an electrical device and a fault location method, which can accurately locate the cause of the fault.

[0005] In a first aspect, the present application provides a high-voltage sampling circuit, which includes a sampling drive circuit, a sampling feedback circuit, and a voltage sampling circuit;

[0006] The microcontrol unit outside the high-voltage sampling circuit is connected to the sampling drive circuit, the sampling feedback circuit and the voltage sampling circuit respectively; the voltage sampling circuit is used to collect the voltage at one end of the relay;

[0007] The sampling drive circuit is also connected to one end of the relay and the sampling feedback circuit respectively, and is used to conduct the high-voltage sampling loop according to the drive signal output by the micro control unit;

[0008] The sampling feedback circuit is also connected to the voltage sampling circuit to output a self-test signal to the microcontroller unit; wherein the self-test signal is used to indicate whether the high-voltage sampling circuit is normal;

[0009] Wherein, the sampling drive circuit includes a switching circuit and an isolation element;

[0010] A first end of the switch circuit is connected to the micro control unit, and a second end of the switch circuit is connected to a first end of the isolation element and a first end of the sampling feedback circuit respectively;

[0011] The second end of the isolation element is connected to one end of the relay, the third end of the isolation element is connected to the second end of the sampling feedback circuit, and the fourth end of the isolation element is connected to the first power supply end.

[0012] In some embodiments, when the self-test signal indicates that the high-voltage sampling circuit is normal, the sampling drive circuit conducts a connection between one end of the relay and the sampling feedback circuit, and the sampling feedback circuit conducts a connection between one end of the relay and the voltage sampling circuit, and the sampling voltage is the voltage at one end of the relay;

[0013] When the self-test signal indicates that the high-voltage sampling circuit is abnormal, the sampling drive circuit disconnects one end of the relay from the sampling feedback circuit, and the sampling voltage becomes an abnormal voltage.

[0014] In the technical solution provided in the embodiment of the present application, the sampling drive circuit, the sampling feedback circuit and the voltage sampling circuit cooperate with each other, which can not only realize the self-test of the high-voltage sampling circuit, but also perform voltage sampling on one end of the relay, providing a basis for accurately locating the cause of the relay failure to conduct.

[0015] In some embodiments, the switch circuit is turned on according to the driving signal output by the micro control unit, and the first end of the isolation element is grounded; the isolation element conducts the connection between one end of the relay and the sampling feedback circuit;

[0016] Alternatively, the isolation element disconnects one end of the relay from the sampling feedback circuit.

[0017] In some embodiments, the switch circuit includes a first resistor, a second resistor, and a switch tube;

[0018] The first end of the first resistor is connected to the micro control unit, and the second end of the first resistor is connected to the first end of the second resistor and the control electrode of the switch tube respectively;

[0019] The second end of the second resistor is grounded;

[0020] The first electrode of the switch tube is connected to the first end of the isolation element and the first end of the sampling feedback circuit respectively.

[0021] In the technical solution provided in the embodiment of the present application, the switch tube and the isolation element cooperate to drive the sampling feedback circuit to perform self-test feedback, and drive the voltage sampling circuit to perform voltage sampling, providing support for accurate fault location.

[0022] In some embodiments, the sampling drive circuit further includes a plurality of voltage dividing resistors, and the plurality of voltage dividing resistors are connected in series to form a series circuit;

[0023] The second end of the isolation element is connected to the first end of the series circuit, and the second end of the series circuit is connected to one end of the relay.

[0024] In the technical solution provided in the embodiment of the present application, the voltage divider resistor is used to reduce the current of the input isolation element, further reducing the current of the input sampling feedback circuit and the voltage sampling circuit, thereby protecting the sampling drive circuit, the sampling feedback circuit and the voltage sampling circuit.

[0025] In some embodiments, the sampling feedback circuit includes a signal generator and a signal receiver;

[0026] The first end of the signal generator is connected to the sampling drive circuit, and the second end of the signal generator is connected to the voltage sampling circuit;

[0027] The first end of the signal receiver is connected to the sampling drive circuit, the second end of the signal receiver is connected to the micro control unit, and the third end of the signal receiver is connected to the first power supply end;

[0028] If the sampling drive circuit conducts the connection between the signal generator and one end of the relay, the signal generator conducts the connection between the voltage sampling circuit and one end of the relay and outputs a feedback signal; the signal receiver receives the feedback signal and outputs a self-test signal indicating that the high-voltage sampling circuit is normal to the micro control unit;

[0029] If the sampling drive circuit fails to conduct the connection between the signal generator and one end of the relay, the signal receiver outputs a self-test signal indicating abnormality of the high-voltage sampling circuit to the micro control unit.

[0030] In the technical solution provided in the embodiment of the present application, the signal generator and the signal receiver cooperate with each other to realize the feedback of the self-test results of the sampling circuit, providing a basis for accurately locating the cause of the fault.

[0031] In some embodiments, the voltage sampling circuit includes an amplifier, a sampling chip, and a filter circuit;

[0032] The positive input terminal of the amplifier is connected to the sampling feedback circuit and the filtering circuit respectively, the negative input terminal of the amplifier is connected to the output terminal of the amplifier and the sampling chip respectively, the positive power supply terminal of the amplifier is connected to the second power supply terminal, and the negative power supply terminal of the amplifier is grounded.

[0033] In the technical solution provided in the embodiment of the present application, the amplifier and the sampling chip can perform voltage sampling on one end of the relay to obtain a first sampling voltage, which provides a basis for subsequently judging whether the relay is normal based on the first sampling voltage and the second sampling voltage, thereby helping to locate the fault.

[0034] In some embodiments, the filter circuit includes a filter resistor, a first capacitor, and a second capacitor;

[0035] The positive input terminal of the amplifier is connected to the first terminal of the filter resistor, the first terminal of the first capacitor, and the first terminal of the second capacitor respectively;

[0036] The second end of the filter resistor is connected to the second end of the second capacitor and the sampling chip respectively;

[0037] The second terminal of the first capacitor is grounded.

[0038] In a second aspect, the present application further provides a fault locating circuit, the fault locating circuit comprising a microcontroller unit and two high-voltage sampling circuits as described in any one of the first aspects;

[0039] Two high-voltage sampling circuits sample the voltage at both ends of the relay respectively;

[0040] The microcontrol unit obtains a fault location result based on the self-test signals of the two high-voltage sampling circuits and the two sampling voltages; the fault location result is used to indicate whether each high-voltage sampling circuit is normal and whether the relay is normal.

[0041] In a third aspect, the present application further provides an electrical device, which includes a relay, a battery, and the fault location circuit as described in the second aspect.

[0042] In a fourth aspect, the present application further provides a fault location method, which is applied to the fault location circuit as described in the second aspect, wherein the fault location circuit includes a microcontroller unit, a first high-voltage sampling circuit, and a second high-voltage sampling circuit; the method includes:

[0043] Performing self-test through a first high-voltage sampling circuit and sampling the voltage of a first end of the main positive relay to obtain a first self-test signal and a first sampling voltage;

[0044] Performing self-test through the second high-voltage sampling circuit and sampling the voltage of the second end of the main positive relay to obtain a second self-test signal and a second sampling voltage;

[0045] The microcontroller unit obtains a fault location result based on the first self-test signal, the second self-test signal, the first sampling voltage and the second sampling voltage; the fault location result is used to indicate whether the sampling circuit and the main positive relay are normal.

[0046] In the technical solution provided in the embodiment of the present application, the microcontroller unit, the first high-voltage sampling circuit and the second high-voltage sampling circuit cooperate with each other to realize self-test of the sampling circuit and voltage sampling at both ends of the main positive relay. It can be accurately determined based on the self-test situation and the sampling voltage whether the failure of the main positive relay to conduct is caused by an abnormality in the sampling circuit or an abnormality in the main positive relay itself. That is, the cause of the fault can be accurately located, providing a basis for the maintenance of the battery pack.

[0047] In some embodiments, the first high-voltage sampling circuit includes a sampling drive circuit, a sampling feedback circuit, and a voltage sampling circuit; performing self-testing by the first high-voltage sampling circuit and sampling the voltage of the first end of the relay to obtain a first self-test signal and a first sampled voltage includes:

[0048] The sampling drive circuit receives the driving signal output by the micro control unit, outputs a first self-test signal indicating whether the first high-voltage sampling circuit is normal to the micro control unit through the sampling feedback circuit, and outputs a first sampling voltage to the micro control unit through the voltage sampling circuit.

[0049] In some embodiments, receiving a drive signal output by a microcontroller unit through a sampling drive circuit, outputting a first self-test signal indicating whether a first high-voltage sampling circuit is normal to the microcontroller unit through a sampling feedback circuit, and outputting a first sampling voltage to the microcontroller unit through a voltage sampling circuit include:

[0050] The sampling drive circuit receives the drive signal output by the micro control unit, and connects the first end of the main positive relay to the sampling feedback circuit;

[0051] Outputting a first self-test signal indicating that the first high-voltage sampling circuit is normal to the micro control unit through the sampling feedback circuit, and conducting the connection between the first end of the main positive relay and the voltage sampling circuit;

[0052] The first sampling voltage is output to the micro control unit through the voltage sampling circuit; wherein the first sampling voltage is the voltage of the first end of the main positive relay.

[0053] In the technical solution provided in the embodiment of the present application, the sampling drive circuit, the sampling feedback circuit and the voltage sampling circuit cooperate with each other to realize self-test of the first sampling circuit and voltage sampling of the first end of the main positive relay, providing a basis for subsequent accurate positioning of the cause of the fault.

[0054] In some embodiments, receiving a drive signal output by a microcontroller unit through a sampling drive circuit and connecting the first end of the relay to the sampling feedback circuit includes:

[0055] When the switch circuit is turned on according to the driving signal output by the micro control unit, the switch circuit connects the isolation element to the ground, and the isolation element conducts the connection between the first end of the relay and the sampling feedback circuit.

[0056] In the technical solution provided in the embodiment of the present application, the switch tube and the isolation element cooperate to drive the sampling feedback circuit to perform self-test feedback and drive the voltage sampling circuit to perform voltage sampling, providing a basis for subsequent accurate positioning of the cause of the fault.

[0057] In some embodiments, the sampling feedback circuit includes a signal generator and a signal receiver, outputs a first self-test signal indicating that the first high-voltage sampling circuit is normal to the microcontroller unit through the sampling feedback circuit, and connects the first end of the relay to the voltage sampling circuit, including:

[0058] After being connected to the first end of the relay, the signal generator switches on the connection between the voltage sampling circuit and the first end of the relay and outputs a feedback signal;

[0059] The feedback signal is received through the signal receiver, and a first self-test signal is output to the micro control unit.

[0060] In the technical solution provided in the embodiment of the present application, the signal generator and the signal receiver cooperate with each other to implement self-test feedback, provide support for determining whether the sampling circuit is normal, and help accurately locate the cause of the fault.

[0061] In some embodiments, the voltage sampling circuit includes an amplifier and a sampling chip; outputting a first sampling voltage to the microcontroller unit through the voltage sampling circuit includes:

[0062] Following the voltage of the first terminal of the relay through the amplifier, and outputting a following voltage;

[0063] The following voltage is sampled by a sampling chip, and a first sampling voltage is output to the micro control unit.

[0064] In the technical solution provided in the embodiment of the present application, the amplifier forms a follower circuit, which can follow the voltage at the first end of the relay, so that the sampling chip can sample the voltage at the first end of the relay to obtain a first sampling voltage, which provides support for subsequent judgment of whether the relay is normal based on the first sampling voltage, and can help accurately locate the cause of the fault.

[0065] In some embodiments, receiving a drive signal output by a microcontroller unit through a sampling drive circuit, outputting a first self-test signal indicating whether a first high-voltage sampling circuit is normal to the microcontroller unit through a sampling feedback circuit, and outputting a first sampling voltage to the microcontroller unit through a voltage sampling circuit include:

[0066] receiving a driving signal through the sampling driving circuit and disconnecting the first end of the relay from the sampling feedback circuit;

[0067] Outputting a first self-test signal indicating an abnormality of the first high-voltage sampling circuit to the microcontroller unit through the sampling feedback circuit;

[0068] A first sampling voltage is output to the micro control unit through a voltage sampling circuit; wherein the first sampling voltage is an abnormal voltage.

[0069] In the technical solution provided in the embodiment of the present application, the sampling drive circuit, the sampling feedback circuit and the voltage sampling circuit cooperate with each other to realize self-test of the high-voltage sampling circuit and voltage sampling of the first end of the relay, providing a basis for subsequent accurate positioning of the cause of the fault.

[0070] In some embodiments, the sampling feedback circuit includes a signal generator and a signal receiver, and outputs a first self-test signal indicating an abnormality of the first high-voltage sampling circuit to the microcontroller unit through the sampling feedback circuit, including:

[0071] When the signal generator is not connected to the first end of the relay, the signal receiver outputs a first self-test signal indicating that the first high-voltage sampling circuit is abnormal to the micro control unit.

[0072] In the technical solution provided in the embodiment of the present application, the signal generator and the signal receiver cooperate with each other to implement self-test feedback, provide support for determining whether the sampling circuit is normal, and help accurately locate the cause of the fault. BRIEF DESCRIPTION OF THE DRAWINGS

[0073] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the optional embodiments below. The accompanying drawings are for illustration purposes only and are not to be considered as limiting the present application. The same reference numerals are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

[0074] Figure 1 This is one of the structural diagrams of the high-voltage sampling circuit according to one embodiment of the present application;

[0075] Figure 2 This is the second structural diagram of the high-voltage sampling circuit according to an embodiment of the present application;

[0076] Figure 3 This is the third structural diagram of the high-voltage sampling circuit according to an embodiment of the present application;

[0077] Figure 4 This is the fourth structural diagram of the high-voltage sampling circuit according to an embodiment of the present application;

[0078] Figure 5 This is the fifth structural diagram of the high-voltage sampling circuit according to one embodiment of the present application;

[0079] Figure 6 This is the sixth structural diagram of the high-voltage sampling circuit according to one embodiment of the present application;

[0080] Figure 7 This is the seventh structural diagram of the high-voltage sampling circuit according to one embodiment of the present application;

[0081] Figure 8is a structural diagram of a fault location circuit according to an embodiment of the present application;

[0082] Figure 9 This is a schematic structural diagram of an electrical device according to an embodiment of the present application;

[0083] Figure 10 This is a flowchart of a fault location method according to an embodiment of the present application;

[0084] Figure 11 1 is a flow chart of the self-test and voltage sampling steps of an embodiment of the present application;

[0085] Figure 12 1 is a flow chart of self-test feedback and conduction connection steps according to an embodiment of the present application;

[0086] Figure 13 1 is a flow chart of the step of outputting a first sampling voltage according to an embodiment of the present application;

[0087] Figure 14 It is a flowchart of the self-test and voltage sampling steps of another embodiment of the present application.

[0088] Description of reference numerals:

[0089] 10. Fault location circuit; 11. Micro control unit; 12. High-voltage sampling circuit;

[0090] K, relay; 121, sampling drive circuit; 1211, switching circuit; 1231, filter circuit;

[0091] 122, sampling feedback circuit; 123, voltage sampling circuit; R1, first resistor;

[0092] R2, second resistor; Q1, switch tube; G, isolation element; B, battery; R4, fourth resistor;

[0093] R5, fifth resistor; R6, sixth resistor; R7, seventh resistor; R8, eighth resistor;

[0094] F, signal generator; J, signal receiver; Op, amplifier; X, sampling chip;

[0095] R9, filter resistor; C1, first capacitor; C2, second capacitor; C3, third capacitor. DETAILED DESCRIPTION

[0096] The following embodiments of the technical solution of the present application will be described in detail with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application and are therefore only examples and are not intended to limit the scope of protection of the present application.

[0097] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned figure descriptions are intended to cover non-exclusive inclusions.

[0098] In the description of the embodiments of this application, the technical terms "first" and "second" are used only to distinguish different objects and should not be understood to indicate or imply relative importance or implicitly specify the quantity, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, the meaning of "plurality" is more than two, unless otherwise clearly and specifically defined.

[0099] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0100] In the description of the embodiments of this application, the term "and / or" is simply a description of the association relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent the following three situations: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this document generally indicates that the associated objects are in an "or" relationship.

[0101] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0102] In the description of the embodiments of the present application, unless otherwise expressly specified or limited, technical terms such as "installed," "connected," "connected," and "fixed" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; internal connections between two components or interactions between two components. Those skilled in the art can understand the specific meanings of the above terms in the embodiments of the present application based on specific circumstances.

[0103] With the development of new energy technologies, batteries are being used in an increasingly diverse range of applications. For example, new energy vehicles, intelligent robots, and drones are all powered by batteries. These battery packs typically include relays, a battery management system, and batteries. When the relay is on, the battery can power the load; when the relay is off, the battery stops supplying power.

[0104] In actual use, a relay failure occurs, and when the battery pack is returned for repair, the fault cannot be reproduced. Currently, fault location for relay failure is primarily based on the voltage across the relay. However, even if the voltage across the relay is abnormal, it is impossible to distinguish whether the relay failure is caused by an abnormal sampling circuit or the relay itself, making it difficult to accurately locate the cause of the fault.

[0105] To address the above-mentioned issues, an embodiment of the present application provides a high-voltage sampling circuit, which includes a sampling drive circuit, a sampling feedback circuit, and a voltage sampling circuit; the voltage sampling circuit collects the voltage at one end of the relay; the sampling drive circuit conducts the high-voltage sampling circuit according to the drive signal output by the microcontroller unit; the sampling feedback circuit outputs a self-test signal to the microcontroller unit; the self-test signal is used to indicate whether the high-voltage sampling circuit is normal. In the technical solution of the embodiment of the present application, the high-voltage sampling circuit can perform a self-test to determine whether it is normal. Therefore, during the fault location process, it can be accurately distinguished whether the abnormality is in the sampling circuit or in the relay itself, thereby accurately locating the cause of the relay's inability to conduct, thereby providing a basis for repairing the battery pack.

[0106] According to some embodiments of the present application, referring to Figure 1 The high-voltage sampling circuit 12 includes a sampling drive circuit 121, a sampling feedback circuit 122 and a voltage sampling circuit 123; the microcontroller unit 11 outside the high-voltage sampling circuit 12 is respectively connected to the sampling drive circuit 121, the sampling feedback circuit 122 and the voltage sampling circuit 123; the voltage sampling circuit 123 is used to collect the voltage at one end of the relay K; the sampling drive circuit 121 is also respectively connected to one end of the relay K and the sampling feedback circuit 122, and is used to turn on the high-voltage sampling loop according to the driving signal output by the microcontroller unit 11; the sampling feedback circuit 122 is also connected to the voltage sampling circuit 123; the sampling drive circuit 121 receives the driving signal output by the microcontroller unit 11, and is used to output a self-test signal to the microcontroller unit 11; wherein the self-test signal is used to indicate whether the high-voltage sampling circuit 12 is normal.

[0107] Among them, when the self-test signal indicates that the high-voltage sampling circuit is normal, the sampling drive circuit 121 connects the connection between one end of the relay K and the sampling feedback circuit 122, and the sampling feedback circuit 122 connects the connection between one end of the relay K and the voltage sampling circuit 123, and the sampling voltage is the voltage at one end of the relay K; when the self-test signal indicates that the high-voltage sampling circuit 12 is abnormal, the sampling drive circuit 121 disconnects the connection between one end of the relay K and the sampling feedback circuit 122, and the sampling voltage is the abnormal voltage.

[0108] In the embodiment of the present application, the high-voltage sampling circuit 12 includes a sampling drive circuit 121, a sampling feedback circuit 122, and a voltage sampling circuit 123. The microcontroller unit 11 is connected to the sampling drive circuit 121, the sampling feedback circuit 122, and the voltage sampling circuit 123, respectively. The sampling drive circuit 121 is also connected to one end of the relay K and the sampling feedback circuit 122, respectively. The sampling feedback circuit 122 is also connected to the voltage sampling circuit 123.

[0109] During the fault location process, the micro control unit 11 outputs a control signal to the relay K to control the relay K to be turned on; the micro control unit 11 also outputs a drive signal to the sampling drive circuit 121 .

[0110] When sampling drive circuit 121 is functioning normally, upon receiving a drive signal, sampling drive circuit 121 connects one end of relay K to sampling feedback circuit 122, thereby connecting one end of relay K to sampling feedback circuit 122. Sampling feedback circuit 122 outputs a self-test signal to microcontroller unit 11, indicating that high-voltage sampling circuit 12 is functioning normally. Furthermore, sampling feedback circuit 122 connects one end of relay K to voltage sampling circuit 123. Voltage sampling circuit 123 samples the voltage at one end of relay K and outputs the sampled voltage to microcontroller unit 11.

[0111] If sampling drive circuit 121 is abnormal, after receiving the drive signal, sampling drive circuit 121 cannot connect one end of relay K to sampling feedback circuit 122. In other words, one end of relay K cannot be connected to sampling feedback circuit 122. In this case, sampling feedback circuit 122 outputs a self-test signal to microcontroller unit 11. This self-test signal indicates an abnormality in high-voltage sampling circuit 12. Furthermore, because sampling feedback circuit 122 is not connected to one end of relay K, voltage sampling circuit 123 cannot be connected to one end of the relay. Consequently, the sampled voltage output by voltage sampling circuit 123 to microcontroller unit 11 is an abnormal voltage.

[0112] The microcontroller unit 11 receives a self-test signal and a sampled voltage. If the self-test signal indicates that the high-voltage sampling circuit 12 is functioning properly, the microcontroller unit 11 determines that the high-voltage sampling circuit 12 is functioning properly. Subsequently, if the other high-voltage sampling circuit 12 is also functioning properly, the microcontroller unit 11 determines whether relay K is functioning properly based on the two sampled voltages, thereby locating the fault. If the self-test signal indicates that the high-voltage sampling circuit 12 is abnormal, the microcontroller unit 11 directly determines that the sampling circuit is abnormal. This fault location result can serve as a basis for battery pack repair.

[0113] In the above embodiment, the high-voltage sampling circuit includes a sampling drive circuit, a sampling feedback circuit, and a voltage sampling circuit; when the sampling drive circuit is normal, the sampling feedback circuit outputs a self-test signal indicating that the high-voltage sampling circuit is normal to the micro-control unit, and the voltage sampling circuit outputs a sampled voltage corresponding to one end of the relay to the micro-control unit; when the sampling drive circuit is abnormal, the sampling feedback circuit outputs a self-test signal indicating that the high-voltage sampling circuit is abnormal to the micro-control unit, and the voltage sampling circuit outputs an abnormal voltage to the micro-control unit. In the technical solution provided in the embodiment of the present application, the sampling drive circuit, the sampling feedback circuit, and the voltage sampling circuit cooperate with each other, not only to realize the self-test of the high-voltage sampling circuit, but also to perform voltage sampling on one end of the relay, providing a basis for accurately locating the cause of the relay failure.

[0114] In some embodiments, reference Figure 2 The sampling drive circuit 121 includes a switch circuit 1211 and an isolation element G; a first end of the switch circuit 1211 is connected to the micro control unit 11, and a second end of the switch circuit 1211 is connected to the first end of the isolation element G and the first end of the sampling feedback circuit 122, respectively; a second end of the isolation element G is connected to one end of the relay K, a third end of the isolation element G is connected to the second end of the sampling feedback circuit 122, and a fourth end of the isolation element G is connected to the first power supply terminal VCC1; the switch circuit 1211 is turned on according to the drive signal output by the micro control unit 11, and the first end of the isolation element G is grounded; the isolation element G connects one end of the relay K to the sampling feedback circuit 122; or, the isolation element G disconnects one end of the relay K from the sampling feedback circuit 122.

[0115] In the embodiment of the present application, the sampling and driving circuit 121 includes a switch circuit 1211 and an isolation element G.

[0116] During the fault location process, the micro control unit 11 outputs a control signal to the relay K to control the relay K to be turned on; the micro control unit 11 also outputs a drive signal to the switch circuit 1211 .

[0117] If the switch circuit 1211 is functioning properly, the first terminal of the isolation element G is grounded to GND, and the first terminal of the sampling feedback circuit 122 is also grounded to GND. If the isolation element G is functioning properly, then with the first terminal grounded to GND and the fourth terminal connected to the first power supply terminal VCC1, the isolation element G can connect one terminal of the relay K to the second terminal of the sampling feedback circuit 122. The first terminal of the sampling feedback circuit 122 is grounded to GND. After being connected to one terminal of the relay K, the sampling feedback circuit 122 outputs a self-test signal to the microcontroller unit 11. This self-test signal indicates that the high-voltage sampling circuit 12 is functioning properly. Furthermore, the sampling feedback circuit 122 connects one terminal of the relay K to the voltage sampling circuit 123; the voltage sampling circuit 123 samples the voltage at one terminal of the relay K and outputs the sampled voltage to the microcontroller unit 11.

[0118] If the switch circuit 1211 is functioning properly, the first end of the isolation element G is grounded to GND, and the first end of the sampling feedback circuit 122 is also grounded to GND. However, if the isolation element G is abnormal, the isolation element G cannot connect one end of the relay K to the second end of the sampling feedback circuit 122. In other words, the isolation element G disconnects one end of the relay K from the sampling feedback circuit 122. In this case, the sampling feedback circuit 122 outputs a self-test signal to the microcontroller unit 11, indicating an abnormality in the high-voltage sampling circuit 12. Simultaneously, the sampling feedback circuit 122 cannot connect one end of the relay K to the voltage sampling circuit 123. Consequently, the voltage sampling circuit 123 outputs an abnormal voltage to the microcontroller unit 11.

[0119] If the switch circuit 1211 is abnormal, the first end of the isolation element G is disconnected from ground GND. In this case, the isolation element G cannot function properly and cannot connect one end of the relay K to the second end of the sampling feedback circuit 122. In other words, the isolation element G disconnects one end of the relay K from the sampling feedback circuit 122. As a result, the sampling feedback circuit 122 outputs a self-test signal to the microcontroller unit 11. This self-test signal indicates an abnormality in the high-voltage sampling circuit 12. Simultaneously, the sampling feedback circuit 122 cannot connect one end of the relay K to the voltage sampling circuit 123. Consequently, the voltage sampling circuit 123 outputs an abnormal voltage to the microcontroller unit 11.

[0120] In the above-mentioned embodiment, the sampling drive circuit includes a switching circuit and an isolation element. In the technical solution provided by the embodiment of the present application, the switching circuit and the isolation element cooperate to drive the sampling feedback circuit to perform self-test feedback and drive the voltage sampling circuit to perform voltage sampling, providing support for accurate fault location.

[0121] According to some embodiments of the present application, referring to Figure 3The switch circuit 1211 includes a first resistor R1, a second resistor R2, and a switch tube Q1; a first end of the first resistor R1 is connected to the micro control unit 11, and a second end of the first resistor R1 is respectively connected to a first end of the second resistor R2 and a control electrode of the switch tube Q1; a second end of the second resistor R2 is grounded GND; and a first electrode of the switch tube Q1 is respectively connected to a first end of the isolation element G and a first end of the sampling feedback circuit 122.

[0122] In the embodiment of the present application, the switch circuit 1211 includes a first resistor R1, a second resistor R2, and a switch Q1. A first end of the first resistor R1 is connected to the microcontroller unit 11, and a second end of the first resistor R1 is connected to a first end of the second resistor R2 and a control electrode of the switch Q1. A second end of the second resistor R2 is connected to ground GND. A first electrode of the switch Q1 is connected to a first end of an isolation element G and a first end of a sampling feedback circuit 122. A second end of the isolation element G is connected to one end of a relay K, a third end of the isolation element G is connected to a second end of the sampling feedback circuit 122, and a fourth end of the isolation element G is connected to a first power supply terminal VCC1.

[0123] During the fault location process, the micro control unit 11 outputs a control signal to the relay K to control the relay K to be turned on; the micro control unit 11 also outputs a drive signal to the first resistor R1, and the drive signal is transmitted to the control electrode of the switch tube Q1 through the first resistor R1.

[0124] If switch Q1 is functioning normally, the drive signal can turn on switch Q1, grounding the first terminal of isolation element G to GND, and the first terminal of sampling feedback circuit 122 to GND. If isolation element G is functioning normally, then with its first terminal connected to GND and its fourth terminal connected to the first power supply terminal VCC, isolation element G can connect one terminal of relay K to the second terminal of sampling feedback circuit 122. The first terminal of sampling feedback circuit 122 is grounded to GND. After connecting to one terminal of relay K, sampling feedback circuit 122 outputs a self-test signal to microcontroller unit 11. This self-test signal indicates that high-voltage sampling circuit 12 is functioning normally. Furthermore, sampling feedback circuit 122 connects one terminal of relay K to voltage sampling circuit 123; voltage sampling circuit 123 samples the voltage at one terminal of relay K and outputs a first sampled voltage to microcontroller unit 11.

[0125] If switch Q1 is normal, the drive signal turns on switch Q1, the first end of isolation element G is grounded to GND, and the first end of sampling feedback circuit 122 is grounded to GND. However, if isolation element G is abnormal, isolation element G cannot connect one end of relay K to the second end of sampling feedback circuit 122. In other words, isolation element G disconnects one end of relay K from sampling feedback circuit 122. In this case, sampling feedback circuit 122 outputs a self-test signal to microcontroller unit 11. This self-test signal indicates an abnormality in high-voltage sampling circuit 12. Simultaneously, sampling feedback circuit 122 cannot connect one end of relay K to voltage sampling circuit 123. Therefore, voltage sampling circuit 123 outputs an abnormal voltage to microcontroller unit 11.

[0126] If switch Q1 is abnormal and the drive signal fails to turn on switch Q1, the first end of isolation element G will be disconnected from ground GND. In this case, isolation element G will not function properly and will not be able to connect one end of relay K to the second end of sampling feedback circuit 122. In other words, isolation element G will disconnect one end of relay K from sampling feedback circuit 122. Consequently, sampling feedback circuit 122 will output a self-test signal to microcontroller unit 11. This self-test signal indicates an abnormality in high-voltage sampling circuit 12. Simultaneously, sampling feedback circuit 122 will also be unable to connect one end of relay K to voltage sampling circuit 123. Consequently, voltage sampling circuit 123 will output an abnormal voltage to microcontroller unit 11.

[0127] The first resistor R1 acts as a current limiter, preventing excessive current in the drive signal from damaging the switch Q1. The second resistor R2 shunts the drive signal, reducing the current flowing into the switch's gate and protecting it. Furthermore, the second resistor R2 acts as a voltage stabilizer, stabilizing the gate-source voltage of the switch Q1 based on the current flowing through it and its resistance.

[0128] In some embodiments, the isolation element G may be an optical coupler, a magnetic coupler, a capacitive isolator or other components.

[0129] In the above embodiment, the switching circuit includes a first resistor, a second resistor, and a switching tube; when the switching tube and the isolation element are normal, the switching tube is turned on according to the drive signal output by the microcontroller unit, grounding the first end of the isolation element, and the isolation element connects one end of the relay to the sampling feedback circuit; when the switch and / or the isolation element are abnormal, the isolation element disconnects the one end of the relay from the sampling feedback circuit. In the technical solution provided in the embodiment of the present application, the switching tube and the isolation element cooperate to drive the sampling feedback circuit to perform self-test feedback, and drive the voltage sampling circuit to perform voltage sampling, providing support for accurately locating faults.

[0130] According to some embodiments of the present application, referring to Figure 4 The sampling drive circuit 121 further includes a plurality of voltage-dividing resistors, including a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, and an eighth resistor R8. The fourth resistor R4, the fifth resistor R5, the sixth resistor R6, the seventh resistor R7, and the eighth resistor R8 are connected in series to form a series circuit. The second end of the isolation element G is connected to the first end of the series circuit, and the second end of the series circuit is connected to one end of the relay K.

[0131] In the embodiment of the present application, the sampling and driving circuit 121 further includes a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, and an eighth resistor R8, which are connected in series to form a series circuit. The isolation element G is not directly connected to one end of the relay K, but is connected to one end of the relay K via the series circuit.

[0132] In some embodiments, the isolation element G is not directly connected to the first power supply terminal VCC1, but is connected to the first power supply terminal VCC1 through a resistor R3. The resistor R3 can reduce the power supply voltage input to the isolation element G and the current input to the isolation element G, thereby protecting the isolation element G.

[0133] In some embodiments, the voltage of the first power terminal VCC1 is 5V.

[0134] In the above embodiment, the sampling drive circuit also includes multiple voltage-dividing resistors. In the technical solution provided in the embodiment of the present application, the voltage-dividing resistors can be used to reduce the current of the input isolation element, further reducing the current of the input sampling feedback circuit and the voltage sampling circuit, thereby protecting the sampling drive circuit, the sampling feedback circuit, and the voltage sampling circuit.

[0135] According to some embodiments of the present application, referring to Figure 5The sampling feedback circuit 122 includes a signal generator F and a signal receiver J; a first end of the signal generator F is connected to the sampling drive circuit 121, and a second end of the signal generator F is connected to the voltage sampling circuit 123; a first end of the signal receiver J is connected to the sampling drive circuit 121, a second end of the signal receiver J is connected to the micro control unit 11, and a third end of the signal receiver J is connected to the first power supply terminal VCC1; if the sampling drive circuit 121 conducts the connection between the signal generator F and one end of the relay K, the signal generator F conducts the connection between the voltage sampling circuit 123 and one end of the relay K and outputs a feedback signal; the signal receiver J receives the feedback signal and outputs a self-test signal to the micro control unit 11 indicating that the high-voltage sampling circuit 12 is normal; if the sampling drive circuit 121 does not conduct the connection between the signal generator F and one end of the relay K, the signal receiver J outputs a self-test signal to the micro control unit 11 indicating that the high-voltage sampling circuit 12 is abnormal.

[0136] In the embodiment of the present application, the sampling feedback circuit 122 includes a signal generator F and a signal receiver J; a first end of the signal generator F is connected to the sampling drive circuit 121, and a second end of the signal generator F is connected to the voltage sampling circuit 123; a first end of the signal receiver J is connected to the sampling drive circuit 121, a second end of the signal receiver J is connected to the micro control unit 11, and a third end of the signal receiver J is connected to the first power supply terminal VCC1.

[0137] During the fault location process, the micro control unit 11 outputs a control signal to the relay K to control the relay K to be turned on; the micro control unit 11 also outputs a drive signal to the first resistor R1, and the drive signal is transmitted to the control electrode of the switch tube Q1 through the first resistor R1.

[0138] If both the switch Q1 and the isolation element G are functioning properly, one end of the relay K can be connected to the first end of the signal generator F. After the signal generator F is connected to one end of the relay K, it outputs a feedback signal, and one end of the relay K is connected to the voltage sampling circuit 123. The signal receiver J receives the feedback signal and outputs a self-test signal to the microcontroller unit 11. This self-test signal indicates that the high-voltage sampling circuit 12 is functioning properly.

[0139] If switch Q1 or isolation element G is abnormal, signal generator F is disconnected from one end of relay K and no feedback signal is output. Signal receiver J, not receiving the feedback signal, outputs a self-test signal to microcontroller unit 11. This self-test signal indicates an abnormality in high-voltage sampling circuit 12. Since signal generator F is disconnected from one end of relay K, voltage sampling circuit 123 is also disconnected from one end of relay K, and thus outputs an abnormal voltage to the microcontroller unit.

[0140] In some embodiments, the signal generator F can be an infrared generator, and the signal receiver J can be an infrared receiver. An infrared generator is a device that emits light within a certain range through an infrared emitting tube. An infrared receiver is a device that receives infrared signals and independently generates output compatible with TTL electrical frequency signals.

[0141] In the above embodiment, the sampling feedback circuit includes a signal generator and a signal receiver; when the sampling drive circuit is normal, the signal generator sends a feedback signal, the signal receiver receives the feedback signal and outputs a self-test signal indicating that the high-voltage sampling circuit is normal to the micro-control unit; when the sampling drive circuit is normal, the signal generator sends a feedback signal, the signal receiver receives the feedback signal and outputs a self-test signal indicating that the high-voltage sampling circuit is normal to the micro-control unit; when the sampling drive circuit is abnormal, the signal generator cannot send a feedback signal, and the signal receiver does not receive the feedback signal and outputs a self-test signal indicating that the high-voltage sampling circuit is abnormal to the micro-control unit. In the technical solution provided in the embodiment of the present application, the signal generator and the signal receiver cooperate with each other to realize the feedback of the self-test results of the sampling circuit, providing a basis for accurately locating the cause of the fault.

[0142] According to some embodiments of the present application, referring to Figure 6 The voltage sampling circuit 123 includes an amplifier Op, a sampling chip X, and a filter circuit 1231; the positive input terminal of the amplifier Op is connected to the sampling feedback circuit 122 and the filter circuit 1231 respectively, the negative input terminal of the amplifier Op is connected to the output terminal of the amplifier Op and the sampling chip X respectively, the positive power supply terminal of the amplifier Op is connected to the second power supply terminal VCC2, and the negative power supply terminal of the amplifier is grounded GND.

[0143] In the embodiment of the present application, the voltage sampling circuit 123 includes an amplifier Op, a sampling chip X, and a filter circuit 1231; the positive input terminal of the amplifier Op is connected to the sampling feedback circuit 122 and the filter circuit 1231, respectively, and the negative input terminal of the amplifier Op is connected to the output terminal of the amplifier Op and the sampling chip X, respectively.

[0144] During the fault location process, the micro control unit 11 outputs a control signal to the relay K to control the relay K to be turned on; the micro control unit 11 also outputs a drive signal to the first resistor R1, and the drive signal is transmitted to the control electrode of the switch tube Q1 through the first resistor R1.

[0145] If both switch Q1 and isolation element G are functioning properly, one end of relay K can be connected to the first end of signal generator F. After signal generator F is connected to one end of relay K, it outputs a feedback signal and connects one end of relay K to the positive input of amplifier Op. Because the negative input of amplifier Op is connected to its output, a voltage follower circuit is formed, whereby the output voltage of amplifier Op follows the input voltage of its positive input. Since the positive input of amplifier Op is connected to one end of relay K, amplifier Op can follow the voltage at the first end of relay K and output the following voltage to sampling chip X. Sampling chip X then outputs a first sampled voltage to microcontroller unit 11 based on the following voltage.

[0146] If the switch Q1 or the isolation element G is abnormal, the signal generator F is not connected to one end of the relay K. In this case, the positive input terminal of the amplifier Op is also not connected to one end of the relay K, and the voltage tracking of one end of the relay K cannot be performed. The sampling chip X will output an abnormal voltage to the micro-control voltage.

[0147] In the above embodiment, the voltage sampling circuit includes an amplifier, a sampling chip and a filter circuit; in the technical solution provided in the embodiment of the present application, the amplifier and the sampling chip can realize voltage sampling at one end of the relay to obtain a sampled voltage, which provides a basis for subsequently judging whether the relay is normal according to the sampled voltages at both ends of the relay, thereby helping to locate the fault.

[0148] In some embodiments, reference Figure 7 The filtering circuit 1231 includes a filtering resistor R9, a first capacitor C1, and a second capacitor C2; the positive input terminal of the amplifier Op is respectively connected to the first end of the filtering resistor R9, the first end of the first capacitor C1, and the first end of the second capacitor C2; the second end of the filtering resistor R9 is respectively connected to the second end of the second capacitor C2 and the sampling chip X; the second end of the first capacitor C1 is grounded GND; and the second end of the third capacitor C3 is grounded GND.

[0149] In the embodiment of the present application, the voltage sampling circuit 123 includes an amplifier Op, a sampling chip X, a filter resistor R9, a first capacitor C1, a second capacitor C2, and a third capacitor C3; the positive input terminal of the amplifier Op is respectively connected to the sampling feedback circuit 122, and the negative input terminal of the amplifier Op is respectively connected to the output terminal of the amplifier Op and the sampling chip X.

[0150] During the fault location process, the micro control unit 11 outputs a control signal to the relay K to control the relay K to be turned on; the micro control unit 11 also outputs a drive signal to the first resistor R1, and the drive signal is transmitted to the control electrode of the switch tube Q1 through the first resistor R1.

[0151] If both switch Q1 and isolation element G are functioning properly, one end of relay K can be connected to the first end of signal generator F. After signal generator F is connected to one end of relay K, it outputs a feedback signal and connects one end of relay K to the positive input of amplifier Op. Because the negative input of amplifier Op is connected to its output, a voltage follower circuit is formed, whereby the output voltage of amplifier Op follows the input voltage of its positive input. Since the positive input of amplifier Op is connected to one end of relay K, amplifier Op can follow the voltage at the first end of relay K and output the following voltage to sampling chip X. Sampling chip X then outputs a first sampled voltage to microcontroller unit 11 based on the following voltage.

[0152] If the switch Q1 or the isolation element G is abnormal, the signal generator F is not connected to one end of the relay K. In this case, the positive input terminal of the amplifier Op is also not connected to one end of the relay K, and the voltage tracking of one end of the relay K cannot be performed. The sampling chip X will output an abnormal voltage to the micro-control voltage.

[0153] The first capacitor C1 acts as an energy storage device, stabilizing the voltage at the positive input of the amplifier Op at the voltage across the first capacitor C1. The filter resistor R9 and the second capacitor C2 act as filters, reducing signals that interfere with the voltage at the positive input of the amplifier Op. The third capacitor C3 also acts as a filter, reducing signals that interfere with the normal operation of the amplifier Op.

[0154] It should be noted that the device connected to the positive input terminal of the amplifier Op and the device connected to the positive power supply terminal of the amplifier Op can be set according to actual conditions.

[0155] In some embodiments, the voltage of the second power terminal VCC2 is 12V.

[0156] In the above embodiment, the voltage sampling circuit includes an amplifier, a sampling chip, a filter resistor, a first capacitor, a second capacitor, and a third capacitor; the amplifier forms a follower circuit that follows the voltage at the first terminal of the relay so that the sampling chip can sample the voltage at the first terminal of the relay. In the technical solution provided in the embodiment of the present application, the amplifier and the sampling chip can sample the voltage at one terminal of the relay to obtain a first sampled voltage, which provides a basis for subsequently determining whether the relay is normal based on the first and second sampled voltages, thereby facilitating fault location.

[0157] According to some embodiments of the present application, referring to Figure 8, provides a fault location circuit, the fault location circuit 10 includes a micro control unit 11 and two high-voltage sampling circuits 12 as in the above embodiment; the two high-voltage sampling circuits 12 respectively sample the voltages at both ends of the relay K; the micro control unit 11 obtains a fault location result based on the self-test signals of the two high-voltage sampling circuits 12 and the two sampled voltages; the fault location result is used to indicate whether each high-voltage sampling circuit 12 is normal and whether the relay is normal.

[0158] In the embodiment of the present application, relay K typically includes a drive coil and two contacts. One contact of relay K is connected to the positive terminal of the battery, and the other contact of relay K is connected to the load. When a control signal is input to the drive coil, the drive coil generates a magnetic field that attracts the two contacts, causing relay K to connect the battery and the load. If relay K fails to conduct, the battery will not be able to power the load.

[0159] The high-voltage sampling circuit 12 includes a microcontroller unit 11 and two high-voltage sampling circuits 12. The microcontroller unit 11 is connected to each of the two high-voltage sampling circuits 12. The two high-voltage sampling circuits 12 have the same internal structure, but differ in that one high-voltage sampling circuit 12 is connected to one end (one contact) of the relay K, while the other high-voltage sampling circuit 12 is connected to the second end (the other contact) of the relay K.

[0160] During fault location, the microcontroller unit 11 sends a control signal to relay K, turning it on. The microcontroller unit 11 then outputs drive signals to two high-voltage sampling circuits 12. The high-voltage sampling circuits 12 receive the drive signals, perform self-tests based on the drive signals, and output self-test signals indicating whether they are functioning properly. Furthermore, the high-voltage sampling circuit 12 samples the voltage at one end of relay K and outputs the sampled voltage.

[0161] The microcontroller unit 11 receives two self-test signals and two sampled voltages. Based on each self-test signal, the microcontroller unit 11 determines whether the corresponding high-voltage sampling circuit 12 is functioning properly. If at least one high-voltage sampling circuit 12 is abnormal, the microcontroller unit 11 directly outputs a fault location result indicating the sampling circuit is abnormal.

[0162] If both high-voltage sampling circuits 12 are normal, the microcontroller unit 11 calculates the voltage difference between the two sampled voltages and compares this difference with a preset voltage threshold. If the voltage difference is less than the preset voltage threshold, it indicates that relay K is normal, and the fault location result is obtained: both the sampling circuits and relay K are normal. In this case, it is necessary to search for other fault causes. If the voltage difference is greater than or equal to the preset voltage threshold, it indicates that relay K is abnormal, and the fault location result is obtained: the sampling circuits are normal, but relay K is abnormal.

[0163] In the above embodiment, the high-voltage sampling circuit includes a microcontroller unit and two high-voltage sampling circuits. The high-voltage sampling circuit can perform self-tests and sample the voltage at one end of the relay, outputting a self-test signal and a sampled voltage. The microcontroller unit determines whether each high-voltage sampling circuit is normal based on the two self-test signals. If both high-voltage sampling circuits are normal, the microcontroller unit determines whether the relay is normal based on the two sampled voltages. It can be seen that the technical solution provided by the embodiment of the present application, through the cooperation between the microcontroller unit and the two high-voltage sampling circuits, can distinguish whether the sampling circuit or the relay itself is abnormal, thereby accurately locating the cause of the relay's inability to conduct, and thus providing a basis for repairing the battery pack.

[0164] According to some embodiments of the present application, referring to Figure 9 , provides an electrical device comprising a relay, a battery and a fault locating circuit as in the above embodiment.

[0165] In this embodiment of the present application, the electrical device includes a relay K, a battery B, and a fault location circuit 10. One end of the relay K is connected to the positive terminal of the battery B, the second end of the relay K is connected to the first terminal of the load R0, and the negative terminal of the battery B is connected to the second terminal of the load R0. When the relay K is turned on, the battery B can power the load R0.

[0166] The fault location circuit 10 includes a microcontroller unit, a first high-voltage sampling circuit, and a second high-voltage sampling circuit. The first high-voltage sampling circuit can perform self-test and sample the voltage of the first end of the relay, and output a first self-test signal and a first sampling voltage; the second high-voltage sampling circuit can also perform self-test and sample the voltage of the second end of the relay, and output a second self-test signal and a second sampling voltage; the microcontroller unit determines whether the first high-voltage sampling circuit is normal based on the first self-test signal, and determines whether the second high-voltage sampling circuit is normal based on the second self-test signal. When both the first high-voltage sampling circuit and the second high-voltage sampling circuit are normal, whether the relay is normal is determined based on the first sampling voltage and the second sampling voltage.

[0167] The technical solution provided in the embodiment of the present application can distinguish whether the abnormality lies in the sampling circuit or the relay itself, thereby accurately locating the cause of the relay failure, and providing a basis for the maintenance of the battery pack.

[0168] According to some embodiments of the present application, referring to Figure 10 A fault location method is provided, which is described by taking the method applied to the above-mentioned fault location circuit as an example. The high-voltage sampling circuit includes a microcontroller unit, a first high-voltage sampling circuit, and a second high-voltage sampling circuit. The method may include the following steps:

[0169] Step 201 : Perform a self-test through a first high-voltage sampling circuit and sample the voltage of a first end of a relay to obtain a first self-test signal and a first sampled voltage.

[0170] During fault location, the microcontroller sends a control signal to the relay, turning it on. The microcontroller outputs a drive signal to the first high-voltage sampling circuit, which performs a self-test based on the drive signal and outputs a first self-test signal indicating whether it is normal. Furthermore, the first high-voltage sampling circuit samples the voltage at the first terminal of the relay and outputs a first sampled voltage.

[0171] Step 202 : Perform a self-test through a second high-voltage sampling circuit and sample the voltage of the second end of the relay to obtain a second self-test signal and a second sampled voltage.

[0172] The microcontroller unit outputs a driving signal to the second high-voltage sampling circuit. The second high-voltage sampling circuit performs self-test according to the driving signal and outputs a second self-test signal indicating whether it is normal. In addition, the second high-voltage sampling circuit also samples the voltage of the second end of the relay and outputs a second sampled voltage.

[0173] Step 203 : The microcontroller obtains a fault location result based on the first self-test signal, the second self-test signal, the first sampling voltage, and the second sampling voltage. The fault location result is used to indicate whether the sampling circuit and the relay are normal.

[0174] The microcontroller unit receives a first self-test signal, a second self-test signal, a first sampling voltage, and a second sampling voltage. The microcontroller unit then determines whether the high-voltage sampling circuit is functioning properly based on the first self-test signal and whether the second high-voltage sampling circuit is functioning properly based on the second self-test signal. If the high-voltage sampling circuit and / or the second high-voltage sampling circuit are determined to be abnormal, the microcontroller unit directly outputs a fault location result indicating the sampling circuit is abnormal.

[0175] If both the first and second high-voltage sampling circuits are functioning normally, the microcontroller unit calculates the voltage difference between the first and second sampled voltages and compares this voltage difference with a preset voltage threshold. If this voltage difference is less than the preset voltage threshold, indicating that the relay is functioning normally, a fault location result is obtained indicating that both the sampling circuit and the relay are functioning normally, assisting maintenance personnel in locating the fault from other perspectives. If this voltage difference is greater than or equal to the preset voltage threshold, indicating that the relay is abnormal, a fault location result is obtained indicating that the sampling circuit is functioning normally but the relay is abnormal.

[0176] In the above embodiment, a first high-voltage sampling circuit performs a self-test and samples the voltage of the first end of the relay to obtain a first self-test signal and a first sampling voltage; a second high-voltage sampling circuit performs a self-test and samples the voltage of the second end of the relay to obtain a second self-test signal and a second sampling voltage; a microcontroller unit obtains a fault location result based on the first self-test signal, the second self-test signal, the first sampling voltage and the second sampling voltage; and the fault location result is used to characterize whether the sampling circuit is normal and whether the relay is normal. In the technical solution provided in the embodiment of the present application, the microcontroller unit, the first high-voltage sampling circuit and the second high-voltage sampling circuit cooperate with each other to realize the self-test of the sampling circuit and the voltage sampling of the two ends of the relay. It is possible to accurately determine whether the failure of the relay to conduct is caused by an abnormality in the sampling circuit or an abnormality in the relay itself based on the self-test condition and the sampling voltage, that is, the cause of the fault can be accurately located, providing a basis for the maintenance of the battery pack.

[0177] In some embodiments, the first high-voltage sampling circuit includes a sampling drive circuit, a sampling feedback circuit, and a voltage sampling circuit; performing self-testing by the first high-voltage sampling circuit and sampling the voltage of the first end of the relay to obtain a first self-test signal and a first sampled voltage includes:

[0178] The sampling drive circuit receives the driving signal output by the micro control unit, outputs a first self-test signal indicating whether the first high-voltage sampling circuit is normal to the micro control unit through the sampling feedback circuit, and outputs a first sampling voltage to the micro control unit through the voltage sampling circuit.

[0179] In one case, referring to Figure 11 , receiving a driving signal output by a microcontroller unit through a sampling driving circuit, outputting a first self-test signal indicating whether a first high-voltage sampling circuit is normal to the microcontroller unit through a sampling feedback circuit, and outputting a first sampling voltage to the microcontroller unit through a voltage sampling circuit, may include the following steps:

[0180] Step 301 : receiving a driving signal outputted by a micro control unit through a sampling driving circuit, and connecting a first terminal of a relay to a sampling feedback circuit.

[0181] During the fault location process, the microcontroller outputs a control signal to the relay to control the relay to be turned on; the microcontroller also outputs a drive signal to the sampling drive circuit.

[0182] When the sampling drive circuit is normal, after receiving the drive signal, the sampling drive circuit connects the first end of the relay to the sampling feedback circuit, that is, connects the first end of the relay to the sampling feedback circuit.

[0183] Step 302: output a first self-test signal indicating that the first high-voltage sampling circuit is normal to the micro control unit through the sampling feedback circuit, and connect the first end of the relay to the voltage sampling circuit.

[0184] After the sampling feedback circuit is connected to the first end of the relay, it outputs a first self-test signal to the microcontroller unit, which indicates that the first high-voltage sampling circuit is normal. In addition, the sampling feedback circuit connects the first end of the relay to the voltage sampling circuit.

[0185] Step 303: Output the first sampling voltage to the micro control unit through the voltage sampling circuit.

[0186] The first sampling voltage is the voltage at the first end of the relay.

[0187] After the voltage sampling circuit is connected to the first end of the relay, it samples the voltage of the first end of the relay and outputs a first sampling voltage to the micro control unit.

[0188] In the above-described embodiment, a sampling drive circuit receives a drive signal output by a microcontroller unit, thereby connecting the first terminal of the relay to the sampling feedback circuit; the sampling feedback circuit outputs a first self-test signal to the microcontroller unit, thereby connecting the first terminal of the relay to the voltage sampling circuit; and the voltage sampling circuit outputs a first sampled voltage to the microcontroller unit. In the technical solution provided in the embodiments of the present application, the sampling drive circuit, the sampling feedback circuit, and the voltage sampling circuit cooperate with each other to achieve self-testing of the high-voltage sampling circuit and voltage sampling at the first terminal of the relay, providing a basis for subsequently accurately locating the cause of the fault.

[0189] According to some embodiments of the present application, the sampling drive circuit includes a switching circuit and an isolation element. In the above embodiment, "receiving the drive signal output by the micro control unit through the sampling drive circuit and connecting the first end of the conductive relay to the sampling feedback circuit" may include: when the drive signal output by the micro control unit is turned on, the switching circuit grounds the first end of the isolation element, and the isolation element connects the first end of the conductive relay to the sampling feedback circuit.

[0190] During the fault location process, the microcontroller outputs a control signal to the relay to control the relay to be turned on; the microcontroller also outputs a drive signal to the first resistor, and the drive signal is transmitted to the control electrode of the switch tube through the first resistor.

[0191] If the switch circuit is functioning properly, the first end of the isolation element is grounded, and the first end of the sampling feedback circuit is grounded. If the isolation element is functioning properly, the first end of the relay can be connected to the second end of the sampling feedback circuit. The first end of the sampling feedback circuit is grounded, and the second end of the sampling feedback circuit is connected to the first end of the relay. The sampling feedback circuit then outputs a first self-test signal to the microcontroller unit. This first self-test signal indicates that the first high-voltage sampling circuit is functioning properly. Furthermore, the sampling feedback circuit connects the first end of the relay to a voltage sampling circuit. The voltage sampling circuit samples the voltage at the first end of the relay and outputs a first sampled voltage to the microcontroller unit.

[0192] In the above embodiment, when the drive signal output by the microcontroller unit is turned on, the switch circuit grounds the first end of the isolation element, thereby connecting the first end of the relay to the sampling feedback circuit. In the technical solution provided in the embodiments of the present application, the switch tube and the isolation element cooperate to drive the sampling feedback circuit to perform self-test feedback and the voltage sampling circuit to perform voltage sampling, providing a basis for subsequently accurately locating the cause of the fault.

[0193] According to some embodiments of the present application, referring to Figure 12 The sampling feedback circuit includes a signal generator and a signal receiver. In the above embodiment, "outputting a first self-test signal indicating that the first high-voltage sampling circuit is normal to the microcontroller unit through the sampling feedback circuit, and connecting the first end of the relay to the voltage sampling circuit" may include the following steps:

[0194] Step 401: After being connected to the first end of the relay, the signal generator switches on the connection between the voltage sampling circuit and the first end of the relay, and outputs a feedback signal.

[0195] During the fault location process, the microcontroller outputs a control signal to the relay to control the relay to be turned on; the microcontroller also outputs a drive signal to the first resistor, and the drive signal is transmitted to the control electrode of the switch tube through the first resistor.

[0196] If the switch tube and the isolation element are normal, the first end of the relay can be connected to the first end of the signal generator. After the signal generator is connected to the first end of the relay, it outputs a feedback signal and connects the first end of the relay to the voltage sampling circuit.

[0197] Step 402: Receive a feedback signal through a signal receiver and output a first self-test signal to a micro control unit.

[0198] The signal receiver receives the feedback signal and outputs a first self-test signal to the micro control unit. At this time, the first self-test signal indicates that the high-voltage sampling circuit is normal.

[0199] In the above embodiment, after being connected to the first terminal of the relay, the signal generator connects the voltage sampling circuit to the first terminal of the relay and outputs a feedback signal. The feedback signal is received by the signal receiver, which then outputs a first self-test signal to the microcontroller unit. In the technical solution provided in the embodiment of the present application, the signal generator and signal receiver cooperate to implement self-test feedback, providing support for determining whether the sampling circuit is functioning properly and helping to accurately locate the cause of the fault.

[0200] According to some embodiments of the present application, referring to Figure 13 The voltage sampling circuit includes an amplifier and a sampling chip; in the above embodiment, "outputting the first sampling voltage to the micro control unit through the voltage sampling circuit" may include the following steps:

[0201] Step 501: Follow the voltage of the first terminal of the relay through an amplifier and output a following voltage.

[0202] During the fault location process, the microcontroller outputs a control signal to the relay to control the relay to be turned on; the microcontroller also outputs a drive signal to the first resistor, and the drive signal is transmitted to the control electrode of the switch tube through the first resistor.

[0203] If the switching tube and isolation element are functioning properly, the first end of the relay can be connected to the first end of the signal generator. After the signal generator is connected to the first end of the relay, it outputs a feedback signal and connects the first end of the relay to the positive input of the amplifier. Since the negative input of the amplifier is connected to the output, a voltage follower circuit is formed, where the output voltage of the amplifier follows the input voltage of the amplifier's positive input. In this way, the amplifier follows the voltage of the first end of the relay and inputs the following voltage into the sampling chip.

[0204] Step 502: Sample the follower voltage through a sampling chip and output a first sampled voltage to a micro control unit.

[0205] The sampling chip samples the follower voltage and outputs a first sampling voltage to the micro control unit.

[0206] In the above embodiment, an amplifier follows the voltage at the first terminal of the relay and outputs a following voltage; a sampling chip samples the following voltage and outputs a first sampled voltage to a microcontroller unit. In the technical solution provided in the embodiment of the present application, the amplifier forms a following circuit that can follow the voltage at the first terminal of the relay, thereby enabling the sampling chip to sample the voltage at the first terminal of the relay to obtain a first sampled voltage. This provides support for subsequently determining whether the relay is functioning properly based on the first sampled voltage, and can help accurately locate the cause of the fault.

[0207] In another case, according to some embodiments of the present application, referring to Figure 14, receiving a driving signal output by a microcontroller unit through a sampling driving circuit, outputting a first self-test signal indicating whether a first high-voltage sampling circuit is normal to the microcontroller unit through a sampling feedback circuit, and outputting a first sampling voltage to the microcontroller unit through a voltage sampling circuit, may include the following steps:

[0208] Step 601: Receive a driving signal through a sampling driving circuit, and disconnect the first end of the relay from the sampling feedback circuit.

[0209] During the fault location process, the microcontroller outputs a control signal to the relay to control the relay to be turned on; the microcontroller also outputs a drive signal to the sampling drive circuit.

[0210] In the case of an abnormality in the sampling drive circuit, after receiving the drive signal, the sampling drive circuit cannot connect the first end of the relay to the sampling feedback circuit, that is, disconnects the first end of the relay from the sampling feedback circuit.

[0211] Step 602: Output a first self-test signal indicating an abnormality in a first high-voltage sampling circuit to a micro control unit through a sampling feedback circuit.

[0212] When the connection with the first end of the relay is disconnected, the sampling feedback circuit outputs a first self-test signal to the micro control unit. At this time, the first self-test signal indicates that the high-voltage sampling circuit is abnormal.

[0213] Step 603: Output a first sampling voltage to the micro control unit through the voltage sampling circuit; wherein the first sampling voltage is an abnormal voltage.

[0214] Since the sampling feedback circuit is disconnected from the first end of the relay, the voltage sampling circuit is also disconnected from the first end of the relay. In this case, the first sampling voltage output by the voltage sampling circuit to the micro control unit is an abnormal voltage.

[0215] In the above-described embodiment, a sampling drive circuit receives a drive signal, disconnecting the first terminal of the relay from the sampling feedback circuit; a first self-test signal indicating an abnormality in the first high-voltage sampling circuit is output to the microcontroller unit via the sampling feedback circuit; and a first sampled voltage is output to the microcontroller unit via the voltage sampling circuit. In the technical solution provided in the embodiments of the present application, the sampling drive circuit, the sampling feedback circuit, and the voltage sampling circuit cooperate to implement self-testing of the high-voltage sampling circuit and voltage sampling at the first terminal of the relay, providing a basis for subsequently accurately locating the cause of the fault.

[0216] According to some embodiments of the present application, the sampling feedback circuit includes a signal generator and a signal receiver. In the above embodiment, "outputting a first self-test signal representing an abnormality of the first high-voltage sampling circuit to the microcontroller unit through the sampling feedback circuit" may include: when the signal generator is not connected to the first end of the relay, the signal receiver outputs the first self-test signal representing an abnormality of the first high-voltage sampling circuit to the microcontroller unit.

[0217] The sampling feedback circuit is disconnected from the first terminal of the relay, that is, the signal generator is disconnected from the first terminal of the relay. In this case, the signal generator cannot output a feedback signal, and the signal receiver does not receive the feedback signal. Therefore, it outputs a first self-test signal to the microcontroller unit. In this case, the first self-test signal indicates an abnormality in the high-voltage sampling circuit.

[0218] In the above embodiment, when the signal generator is not connected to the first terminal of the relay, the signal receiver outputs a first self-test signal to the microcontroller unit indicating an abnormality in the first high-voltage sampling circuit. In the technical solution provided in the embodiments of the present application, the signal generator and signal receiver cooperate to provide self-test feedback, providing support for determining whether the sampling circuit is functioning properly and helping to accurately locate the cause of the fault.

[0219] It should be understood that, although the various steps in the flowcharts involved in the various embodiments described above are displayed in sequence according to the instructions of the arrows, these steps are not necessarily performed in sequence in the order indicated by the arrows. Unless clearly stated herein, the execution of these steps is not strictly limited in order, and these steps can be performed in other orders. Moreover, at least a portion of the steps in the flowcharts involved in the various embodiments described above may include multiple steps or multiple stages, and these steps or stages are not necessarily performed at the same time, but can be performed at different times, and the execution order of these steps or stages is not necessarily performed in sequence, but can be performed in turn or alternately with at least a portion of the steps or stages in other steps or other steps. It is understandable that the various steps in different embodiments can be freely combined as needed, and the various non-contradictory schemes formed by the combination all fall within the scope of protection of this application.

[0220] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0221] The embodiments described above only express several implementation methods of the present application, which are convenient for understanding the technical solutions of the present application in a specific and detailed manner, but they cannot be understood as limiting the scope of protection of the invention patent. It should be pointed out that for ordinary technicians in this field, without departing from the concept of the present application, several variations and improvements can be made, which all fall within the scope of protection of the present application. It should be understood that the technical solutions obtained by those skilled in the art through logical analysis, reasoning or limited experiments on the basis of the technical solutions provided in the present application are all within the scope of protection of the attached claims described in the present application. Therefore, the scope of protection of the patent of this application shall be based on the content of the attached claims, and the description and drawings can be used to interpret the content of the claims.

Claims

1. A high voltage sampling circuit, characterized in that: The high-voltage sampling circuit includes a sampling drive circuit, a sampling feedback circuit and a voltage sampling circuit; The microcontrol unit outside the high-voltage sampling circuit is connected to the sampling drive circuit, the sampling feedback circuit and the voltage sampling circuit respectively; the voltage sampling circuit is used to collect the voltage at one end of the relay; The sampling drive circuit is also connected to one end of the relay and the sampling feedback circuit respectively, and is used to turn on the high-voltage sampling loop according to the drive signal output by the micro control unit; The sampling feedback circuit is also connected to the voltage sampling circuit, and is used to output a self-test signal to the micro control unit; wherein the self-test signal is used to indicate whether the high-voltage sampling circuit is normal; Wherein, the sampling drive circuit includes a switching circuit and an isolation element; The first end of the switch circuit is connected to the micro control unit, and the second end of the switch circuit is connected to the first end of the isolation element and the first end of the sampling feedback circuit respectively; The second end of the isolation element is connected to one end of the relay, the third end of the isolation element is connected to the second end of the sampling feedback circuit, and the fourth end of the isolation element is connected to the first power supply end.

2. The high-voltage sampling circuit according to claim 1, characterized in that: When the self-test signal indicates that the high-voltage sampling circuit is normal, the sampling drive circuit conducts the connection between one end of the relay and the sampling feedback circuit, and the sampling feedback circuit conducts the connection between one end of the relay and the voltage sampling circuit, and the sampling voltage is the voltage at one end of the relay; When the self-test signal indicates that the high-voltage sampling circuit is abnormal, the sampling drive circuit disconnects one end of the relay from the sampling feedback circuit, and the sampling voltage is an abnormal voltage.

3. The high-voltage sampling circuit according to claim 2, characterized in that: The switch circuit is turned on according to the driving signal output by the micro control unit, and the first end of the isolation element is grounded; the isolation element conducts the connection between one end of the relay and the sampling feedback circuit; Alternatively, the isolation element disconnects one end of the relay from the sampling feedback circuit.

4. The high-voltage sampling circuit according to claim 3, characterized in that: The switch circuit includes a first resistor, a second resistor and a switch tube; The first end of the first resistor is connected to the micro control unit, and the second end of the first resistor is connected to the first end of the second resistor and the control electrode of the switch tube respectively; The second end of the second resistor is grounded; The first electrode of the switch tube is connected to the first end of the isolation element and the first end of the sampling feedback circuit respectively.

5. The high-voltage sampling circuit according to claim 4, characterized in that: The sampling drive circuit further includes a plurality of voltage dividing resistors, wherein the plurality of voltage dividing resistors are connected in series to form a series circuit; The second end of the isolation element is connected to the first end of the series circuit, and the second end of the series circuit is connected to one end of the relay.

6. The high-voltage sampling circuit according to claim 2, characterized in that: The sampling feedback circuit includes a signal generator and a signal receiver; The first end of the signal generator is connected to the sampling drive circuit, and the second end of the signal generator is connected to the voltage sampling circuit; The first end of the signal receiver is connected to the sampling drive circuit, the second end of the signal receiver is connected to the micro control unit, and the third end of the signal receiver is connected to the first power supply end; If the sampling drive circuit conducts the connection between the signal generator and one end of the relay, the signal generator conducts the connection between the voltage sampling circuit and one end of the relay and outputs a feedback signal; the signal receiver receives the feedback signal and outputs a self-test signal indicating that the high-voltage sampling circuit is normal to the micro control unit; If the sampling drive circuit fails to conduct the connection between the signal generator and one end of the relay, the signal receiver outputs a self-test signal indicating that the high-voltage sampling circuit is abnormal to the micro control unit.

7. The high-voltage sampling circuit according to claim 2, characterized in that: The voltage sampling circuit includes an amplifier, a sampling chip and a filter circuit; The positive input terminal of the amplifier is connected to the sampling feedback circuit and the filtering circuit respectively, the negative input terminal of the amplifier is connected to the output terminal of the amplifier and the sampling chip respectively, the positive power supply terminal of the amplifier is connected to the second power supply terminal, and the negative power supply terminal of the amplifier is grounded.

8. The high-voltage sampling circuit according to claim 7, characterized in that: The filter circuit includes a filter resistor, a first capacitor and a second capacitor; The positive input terminal of the amplifier is connected to the first end of the filter resistor, the first end of the first capacitor, and the first end of the second capacitor respectively; The second end of the filter resistor is connected to the second end of the second capacitor and the sampling chip respectively; The second terminal of the first capacitor is grounded.

9. A fault location circuit, characterized in that: The fault location circuit comprises a microcontroller unit and two high-voltage sampling circuits according to any one of claims 1 to 8; The two high-voltage sampling circuits respectively sample the voltage at both ends of the relay; The micro control unit obtains a fault location result based on the self-test signals of the two high-voltage sampling circuits and the two sampling voltages; the fault location result is used to indicate whether each of the high-voltage sampling circuits is normal and whether the relay is normal.

10. An electrical device, characterized in that: The electrical device includes a relay, a battery and the fault locating circuit according to claim 9.

11. A fault location method, characterized in that: Applied to the fault locating circuit of claim 9, the fault locating circuit comprising a microcontroller unit, a first high-voltage sampling circuit and a second high-voltage sampling circuit; the method comprising: Performing self-test by the first high-voltage sampling circuit and sampling the voltage of the first end of the relay to obtain a first self-test signal and a first sampling voltage; Performing self-test by the second high-voltage sampling circuit and sampling the voltage of the second end of the relay to obtain a second self-test signal and a second sampling voltage; The microcontroller obtains a fault location result based on the first self-test signal, the second self-test signal, the first sampling voltage and the second sampling voltage; the fault location result is used to indicate whether the sampling circuit is normal and whether the relay is normal.

12. The method according to claim 11, characterized in that The first high-voltage sampling circuit includes a sampling drive circuit, a sampling feedback circuit, and a voltage sampling circuit; the self-testing and voltage sampling of the first end of the relay by the first high-voltage sampling circuit to obtain a first self-test signal and a first sampling voltage include: The driving signal output by the micro control unit is received through the sampling driving circuit, a first self-test signal indicating whether the first high-voltage sampling circuit is normal is output to the micro control unit through the sampling feedback circuit, and the first sampling voltage is output to the micro control unit through the voltage sampling circuit.

13. The method according to claim 12, characterized in that The step of receiving the driving signal output by the micro control unit through the sampling driving circuit, outputting a first self-test signal indicating whether the first high-voltage sampling circuit is normal to the micro control unit through the sampling feedback circuit, and outputting the first sampling voltage to the micro control unit through the voltage sampling circuit includes: Receiving the driving signal output by the micro control unit through the sampling driving circuit, and conducting the connection between the first end of the relay and the sampling feedback circuit; Outputting a first self-test signal indicating that the first high-voltage sampling circuit is normal to the micro control unit through the sampling feedback circuit, and conducting a connection between the first end of the relay and the voltage sampling circuit; The first sampling voltage is output to the micro control unit through the voltage sampling circuit; wherein the first sampling voltage is the voltage of the first end of the relay.

14. The method according to claim 13, characterized in that The step of receiving the driving signal output by the micro control unit through the sampling driving circuit and conducting the connection between the first end of the relay and the sampling feedback circuit includes: In a case where the drive signal output by the micro control unit is turned on, the switch circuit connects the isolation element to the ground, and the isolation element conducts the connection between the first end of the relay and the sampling feedback circuit.

15. The method according to claim 12, characterized in that The sampling feedback circuit includes a signal generator and a signal receiver, and outputting a first self-test signal indicating that the first high-voltage sampling circuit is normal to the micro control unit through the sampling feedback circuit, and conducting a connection between the first end of the relay and the voltage sampling circuit, including: After being connected to the first end of the relay, the signal generator switches on the connection between the voltage sampling circuit and the first end of the relay and outputs a feedback signal; The feedback signal is received by the signal receiver, and the first self-test signal is output to the micro control unit.

16. The method according to claim 12, characterized in that The voltage sampling circuit includes an amplifier and a sampling chip; and outputting the first sampling voltage to the micro control unit through the voltage sampling circuit includes: Following the voltage of the first end of the relay through the amplifier and outputting a following voltage; The following voltage is sampled by the sampling chip, and the first sampling voltage is output to the micro control unit.

17. The method according to claim 12, wherein: The step of receiving the driving signal output by the micro control unit through the sampling driving circuit, outputting a first self-test signal indicating whether the first high-voltage sampling circuit is normal to the micro control unit through the sampling feedback circuit, and outputting the first sampling voltage to the micro control unit through the voltage sampling circuit includes: receiving a driving signal through the sampling driving circuit, and disconnecting the first end of the relay from the sampling feedback circuit; Outputting a first self-test signal indicating an abnormality of the first high-voltage sampling circuit to the micro control unit through the sampling feedback circuit; The first sampling voltage is output to the micro control unit through the voltage sampling circuit; wherein the first sampling voltage is an abnormal voltage.

18. The method according to claim 17, characterized in that The sampling feedback circuit includes a signal generator and a signal receiver, and the first self-test signal indicating an abnormality of the first high-voltage sampling circuit is output to the micro control unit through the sampling feedback circuit, including: In a case where the signal generator is not connected to the first end of the relay, the signal receiver outputs a first self-test signal indicating that the first high-voltage sampling circuit is abnormal to the micro control unit.

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