High-voltage sampling circuit, fault location circuit, electrical equipment, and fault location method

Abstract

This application relates to a high-voltage sampling circuit, a fault location circuit, electrical equipment, and a fault location method. The high-voltage sampling circuit includes a sampling drive circuit, a sampling feedback circuit, and a voltage sampling circuit. A microcontroller unit external to 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 acquire the voltage at one end of a relay. 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 circuit according to the drive signal output by the microcontroller unit. The sampling feedback circuit is also connected to the voltage sampling circuit and is used to output a self-test signal to the microcontroller unit. The self-test signal is used to characterize whether the high-voltage sampling circuit is functioning correctly. Using this application, the cause of a fault can be accurately located.

Description

Technical Field

[0001] This application relates to the field of battery technology, specifically to a high-voltage sampling circuit, a fault location circuit, an electrical device, and a fault location method. Background Technology

[0002] With the development of new energy technologies, batteries are being used in increasingly wider fields. For example, new energy vehicles, intelligent robots, and drones all use battery power. A battery pack typically includes a relay, a battery management system, and the battery itself. When the relay is turned on, the battery can supply power to the load; when the relay is turned 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 originates from a sampling circuit malfunction or a relay malfunction, resulting in inaccurate fault location. Summary of the Invention

[0004] To address the aforementioned issues, this 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 a fault.

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

[0006] The microcontroller 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 acquire 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 turn on the high voltage sampling circuit according to the drive signal output by the microcontroller unit;

[0008] The sampling feedback circuit is also connected to the voltage sampling circuit to output a self-test signal to the microcontroller unit; the self-test signal is used to characterize whether the high-voltage sampling circuit is functioning properly.

[0009] The sampling drive circuit includes a switching circuit and an isolation component;

[0010] The first terminal of the switching circuit is connected to the microcontroller unit, and the second terminal of the switching circuit is connected to the first terminal of the isolation element and the first terminal 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 terminal.

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

[0013] When the self-test signal indicates an abnormality in the high-voltage sampling circuit, the sampling drive circuit disconnects the connection between one end of the relay and the sampling feedback circuit, and the sampling voltage becomes an abnormal voltage.

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

[0015] In some embodiments, the switching circuit is turned on according to the drive signal output by the microcontroller unit, grounding the first terminal of the isolation element; the isolation element turns on the connection between one terminal 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 switching circuit includes a first resistor, a second resistor, and a switching transistor;

[0018] The first end of the first resistor is connected to the microcontroller 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 switching transistor, respectively.

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

[0020] The first terminal of the switching transistor is connected to the first terminal of the isolation element and the first terminal of the sampling feedback circuit, respectively.

[0021] In the technical solution provided in this application embodiment, by cooperating with the switching transistor and the isolation element, the sampling feedback circuit can be driven to perform self-test feedback, and the voltage sampling circuit can be driven to perform voltage sampling, which provides support for accurately locating faults.

[0022] In some embodiments, the sampling drive circuit further includes a plurality of voltage divider resistors, which 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 this application embodiment, the current of the input isolation element can be reduced by using a voltage divider resistor, which further reduces the current of the input sampling feedback circuit and the voltage sampling circuit, and can protect 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 terminal of the signal generator is connected to the sampling drive circuit, and the second terminal 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 microcontroller unit, and the third end of the signal receiver is connected to the first power supply terminal.

[0028] If the sampling drive circuit connects the signal generator to one end of the relay, the signal generator will connect the voltage sampling circuit to one end of the relay and output 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 microcontroller.

[0029] If the sampling drive circuit fails to connect the signal generator to one end of the relay, the signal receiver will output a self-test signal indicating an abnormality in the high-voltage sampling circuit to the microcontroller unit.

[0030] In the technical solution provided in this application embodiment, the signal generator and the signal receiver cooperate with each other to realize the feedback of the self-test results of the sampling circuit, which provides 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 filtering circuit;

[0032] The positive input terminal of the amplifier is connected to the sampling feedback circuit and the filter 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 this application embodiment, the amplifier and sampling chip can perform voltage sampling on one end of the relay to obtain a first sampling voltage, which provides a basis for 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 terminal of the filter resistor is connected to the second terminal of the second capacitor and the sampling chip, respectively.

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

[0038] Secondly, this application also provides a fault location circuit, which includes 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 across the two ends of the relay.

[0040] The microcontroller unit obtains the 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 characterize whether each high-voltage sampling circuit is normal and whether the relay is normal.

[0041] Thirdly, this application also provides an electrical device that includes a relay, a battery, and a fault location circuit as described in the second aspect.

[0042] Fourthly, this application also provides a fault location method applied to the fault location circuit described in the second aspect, the fault location circuit including a microcontroller unit, a first high-voltage sampling circuit, and a second high-voltage sampling circuit; the method includes:

[0043] The first high-voltage sampling circuit performs a self-test and samples the voltage at the first terminal of the main positive relay to obtain the first self-test signal and the first sampling voltage.

[0044] The second high-voltage sampling circuit performs a self-test and samples the voltage at the second terminal of the main positive relay to obtain the second self-test signal and the second sampling voltage.

[0045] The microcontroller obtains the 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 characterize whether the sampling circuit is normal and whether the main positive relay is normal.

[0046] In the technical solution provided in this application embodiment, 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 at both ends of the main positive relay. Based on the self-test results and the sampling voltage, it can be accurately determined whether the failure of the main positive relay to conduct is caused by an abnormality in the sampling circuit or by an abnormality in the main positive relay itself. In other words, 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 and sampling the voltage at the first terminal of the relay through the first high-voltage sampling circuit to obtain a first self-test signal and a first sampling voltage includes:

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

[0049] In some embodiments, a driving signal output by a microcontroller is received via a sampling driving circuit, a first self-test signal characterizing whether the first high-voltage sampling circuit is functioning correctly is output to the microcontroller via a sampling feedback circuit, and a first sampling voltage is output to the microcontroller via a voltage sampling circuit, including:

[0050] The sampling drive circuit receives the drive signal output by the microcontroller and connects the first terminal of the main positive relay to the sampling feedback circuit.

[0051] The sampling feedback circuit outputs a first self-test signal, indicating that the first high-voltage sampling circuit is normal, to the microcontroller unit, and connects the first terminal of the main positive relay to the voltage sampling circuit.

[0052] The voltage sampling circuit outputs a first sampling voltage to the microcontroller unit; wherein, the first sampling voltage is the voltage at the first terminal of the main positive relay.

[0053] In the technical solution provided in this application embodiment, the sampling drive circuit, sampling feedback circuit and voltage sampling circuit cooperate with each other to realize the self-test of the first sampling circuit and the voltage sampling of the first terminal of the main positive relay, which provides a basis for accurately locating the cause of the fault.

[0054] In some embodiments, receiving a drive signal output by the microcontroller through a sampling drive circuit to turn on the connection between the first terminal of the relay and the sampling feedback circuit includes:

[0055] When the drive signal output by the microcontroller is turned on, the switching circuit grounds the isolation element, and the isolation element turns on the connection between the first terminal of the relay and the sampling feedback circuit.

[0056] In the technical solution provided in this application embodiment, the switching transistor and the isolation element work together 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 accurately locating the cause of the fault.

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

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

[0059] The system receives feedback signals through a signal receiver and outputs a first self-test signal to the microcontroller unit.

[0060] In the technical solution provided in this application embodiment, the signal generator and signal receiver cooperate with each other to achieve self-test feedback, which provides support for judging whether the sampling circuit is normal and can help to 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 sampled voltage to the microcontroller unit through the voltage sampling circuit includes:

[0062] The voltage at the first terminal of the relay is followed by an amplifier, and the following voltage is output.

[0063] The sampling chip samples the follower voltage and outputs the first sampled voltage to the microcontroller unit.

[0064] In the technical solution provided in this application embodiment, the amplifier forms a follower circuit, which can follow 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 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 to accurately locate the cause of the fault.

[0065] In some embodiments, a driving signal output by a microcontroller is received via a sampling driving circuit, a first self-test signal characterizing whether the first high-voltage sampling circuit is functioning correctly is output to the microcontroller via a sampling feedback circuit, and a first sampling voltage is output to the microcontroller via a voltage sampling circuit, including:

[0066] The drive signal is received through the sampling drive circuit, and the connection between the first terminal of the relay and the sampling feedback circuit is disconnected.

[0067] The sampling feedback circuit outputs a first self-test signal, representing an abnormality in the first high-voltage sampling circuit, to the microcontroller unit.

[0068] The voltage sampling circuit outputs a first sampling voltage to the microcontroller unit; the first sampling voltage is an abnormal voltage.

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

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

[0071] 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.

[0072] In the technical solution provided in this application embodiment, the signal generator and signal receiver cooperate with each other to achieve self-test feedback, which provides support for judging whether the sampling circuit is normal and can help to accurately locate the cause of the fault. Attached Figure Description

[0073] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the alternative embodiments below. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

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

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

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

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

[0078] Figure 5 This is the fifth schematic diagram of the high-voltage sampling circuit according to an embodiment of this application;

[0079] Figure 6 This is the sixth schematic diagram of the high-voltage sampling circuit according to an embodiment of this application;

[0080] Figure 7 This is the seventh schematic diagram of the high-voltage sampling circuit according to an embodiment of this application;

[0081] Figure 8This is a schematic diagram of the structure of a fault location circuit according to an embodiment of this application;

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

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

[0084] Figure 11 This is a flowchart illustrating the self-test and voltage sampling steps according to an embodiment of this application;

[0085] Figure 12 This is a flowchart illustrating the self-test feedback and conduction connection steps according to an embodiment of this application;

[0086] Figure 13 This is a flowchart illustrating the step of outputting the first sampled voltage according to an embodiment of this application;

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

[0088] Explanation of reference numerals in the attached figures:

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

[0090] K, Relay; 121, Sampling drive circuit; 1211, Switching circuit; 1231, Filtering circuit;

[0091] 122. Sampling feedback circuit; 123. Voltage sampling circuit; R1. First resistor;

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

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

[0096] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0097] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0098] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

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

[0100] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0101] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0102] In the description of the embodiments of this application, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0103] With the development of new energy technologies, batteries are being used in increasingly wider fields. For example, new energy vehicles, intelligent robots, and drones all use battery power. A battery pack typically includes a relay, a battery management system, and the battery itself. When the relay is turned on, the battery can supply power to the load; when the relay is turned off, the battery stops supplying power.

[0104] In practical use, a fault occurs where the relay fails to conduct, and the fault cannot be reproduced when the battery pack is returned for repair. Currently, the main method for locating the fault in a relay that fails to conduct is 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's failure to conduct is caused by a faulty sampling circuit or a faulty relay itself, making it difficult to accurately pinpoint the cause of the fault.

[0105] To address the aforementioned problems, this 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 acquires the voltage at one end of a 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. This self-test signal is used to characterize whether the high-voltage sampling circuit is functioning correctly. In the technical solution of this application, the high-voltage sampling circuit can perform a self-test to determine whether it is functioning correctly. Therefore, during fault location, it can accurately distinguish whether the fault lies with the sampling circuit or the relay itself, thereby accurately locating the cause of the relay's inability to conduct, and providing a basis for battery pack repair.

[0106] According to some embodiments of this application, refer 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. An external microcontroller unit 11 is 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 acquire the voltage at one end of the relay K. The sampling drive circuit 121 is also connected to one end of the relay K and the sampling feedback circuit 122, and is used to activate the high-voltage sampling circuit according to the drive 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 drive signal output by the microcontroller unit 11 and outputs a self-test signal to the microcontroller unit 11. The self-test signal is used to characterize whether the high-voltage sampling circuit 12 is functioning correctly.

[0107] When the self-test signal indicates that the high-voltage sampling circuit is normal, the sampling drive circuit 121 connects one end of the relay K to the sampling feedback circuit 122, and the sampling feedback circuit 122 connects one end of the relay K to 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 one end of the relay K from the sampling feedback circuit 122, and the sampling voltage is the abnormal voltage.

[0108] In this embodiment, 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 microcontroller unit 11 outputs a control signal to the relay K to control the relay K to conduct; the microcontroller unit 11 also outputs a drive signal to the sampling drive circuit 121.

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

[0111] When the sampling drive circuit 121 malfunctions, after receiving the drive signal, it cannot connect one end of relay K to the sampling feedback circuit 122; that is, it cannot connect one end of relay K to the sampling feedback circuit 122. In this case, the sampling feedback circuit 122 outputs a self-test signal to the microcontroller unit 11, indicating that the high-voltage sampling circuit 12 is malfunctioning. Furthermore, since the sampling feedback circuit 122 is not connected to one end of relay K, the voltage sampling circuit 123 cannot be connected to one end of the relay, and the sampled voltage output by the voltage sampling circuit 123 to the microcontroller unit 11 is an abnormal voltage.

[0112] The microcontroller unit 11 receives a self-test signal and a sampling voltage. If the self-test signal indicates that the high-voltage sampling circuit 12 is normal, then the high-voltage sampling circuit 12 is confirmed to be normal. Subsequently, if the other high-voltage sampling circuit 12 is also confirmed to be normal, the fault location result is obtained by determining whether the relay K is normal based on the two sampling voltages. If the self-test signal indicates that the high-voltage sampling circuit 12 is abnormal, then the fault location result of the sampling circuit abnormality is directly obtained. This fault location result can be used as a basis for battery pack repair.

[0113] In the above embodiments, 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 line outputs a self-test signal indicating that the high-voltage sampling circuit is normal to the microcontroller unit, and the voltage sampling circuit outputs the sampling voltage corresponding to one end of the relay to the microcontroller unit. When the sampling drive circuit is abnormal, the sampling feedback line outputs a self-test signal indicating that the high-voltage sampling circuit is abnormal to the microcontroller unit, and the voltage sampling circuit outputs an abnormal voltage to the microcontroller unit. In the technical solution provided by this application, the sampling drive circuit, sampling feedback circuit, and voltage sampling circuit cooperate with each other, which not only enables the self-test of the high-voltage sampling circuit but also allows voltage sampling at one end of the relay, providing a basis for accurately locating the cause of the relay's inability to conduct.

[0114] In some embodiments, refer to Figure 2 The sampling drive circuit 121 includes a switching circuit 1211 and an isolation element G. The first terminal of the switching circuit 1211 is connected to the microcontroller unit 11, and the second terminal of the switching circuit 1211 is connected to the first terminal of the isolation element G and the first terminal of the sampling feedback circuit 122. The second terminal of the isolation element G is connected to one terminal of the relay K, the third terminal of the isolation element G is connected to the second terminal of the sampling feedback circuit 122, and the fourth terminal of the isolation element G is connected to the first power supply terminal VCC1. The switching circuit 1211 is turned on according to the drive signal output by the microcontroller unit 11, grounding the first terminal of the isolation element G; the isolation element G turns on the connection between one terminal of the relay K and the sampling feedback circuit 122; or, the isolation element G disconnects the connection between one terminal of the relay K and the sampling feedback circuit 122.

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

[0116] During the fault location process, the microcontroller unit 11 outputs a control signal to the relay K to control the relay K to conduct; the microcontroller unit 11 also outputs a drive signal to the switching circuit 1211.

[0117] If the switching circuit 1211 is normal, 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 normal, with its first terminal grounded to GND and its fourth terminal connected to the first power supply terminal VCC1, the isolation element G can connect one end of the relay K to the second terminal of the sampling feedback circuit 122. With the first terminal of the sampling feedback circuit 122 grounded to GND and connected to one end 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 normal. Furthermore, the sampling feedback circuit 122 connects one end of the relay K to the voltage sampling circuit 123; the voltage sampling circuit 123 samples the voltage at one end of the relay K and outputs the sampled voltage to the microcontroller unit 11.

[0118] If the switching circuit 1211 is functioning normally, 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. However, if the isolation element G malfunctions, it cannot connect one end of the relay K to the second terminal of the sampling feedback circuit 122; that is, the isolation element G disconnects the connection between one end of the relay K and the sampling feedback circuit 122. In this case, the sampling feedback circuit 122 outputs a self-test signal to the microcontroller unit 11, indicating a malfunction in the high-voltage sampling circuit 12. Simultaneously, the sampling feedback circuit 122 also cannot connect one end of the relay K to the voltage sampling circuit 123; therefore, the voltage sampling circuit 123 outputs an abnormal voltage to the microcontroller unit 11.

[0119] If the switching circuit 1211 malfunctions, the first terminal of the isolation element G is not grounded to GND. In this case, the isolation element G cannot function properly, nor can it connect one end of the relay K to the second terminal of the sampling feedback circuit 122; that is, the isolation element G disconnects the connection between one end of the relay K and the sampling feedback circuit 122. Based on this, the sampling feedback circuit 122 outputs a self-test signal to the microcontroller unit 11, which indicates a malfunction in the high-voltage sampling circuit 12. Simultaneously, the sampling feedback circuit 122 also cannot connect one end of the relay K to the voltage sampling circuit 123; therefore, the voltage sampling circuit 123 outputs an abnormal voltage to the microcontroller unit 11.

[0120] In the above embodiments, the sampling drive circuit includes a switching circuit and an isolation element. In the technical solution provided by this application, the switching circuit and the isolation element work together to drive the sampling feedback circuit for self-test feedback and to drive the voltage sampling circuit for voltage sampling, thus providing support for accurate fault location.

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

[0122] In this embodiment, the switching circuit 1211 includes a first resistor R1, a second resistor R2, and a switching transistor Q1. The first end of the first resistor R1 is connected to the microcontroller unit 11, and the second end of the first resistor R1 is connected to the first end of the second resistor R2 and the control electrode of the switching transistor Q1. The second end of the second resistor R2 is grounded (GND). The first electrode of the switching transistor Q1 is connected to the first end of the isolation element G and the first end of the sampling feedback circuit 122. The second end of the isolation element G is connected to one end of the relay K, the third end of the isolation element G is connected to the second end of the sampling feedback circuit 122, and the fourth end of the isolation element G is connected to the first power supply terminal VCC1.

[0123] During the fault location process, the microcontroller unit 11 outputs a control signal to the relay K to control the relay K to conduct; the microcontroller unit 11 also outputs a drive signal to the first resistor R1, and the drive signal is transmitted to the control electrode of the switching transistor Q1 through the first resistor R1.

[0124] If the switching transistor Q1 is functioning correctly, the drive signal can turn it on, grounding the first terminal of the isolation element G to GND, and the first terminal of the sampling feedback circuit 122 to GND. If the isolation element G is functioning correctly, with its first terminal grounded to GND and its fourth terminal connected to the first power supply terminal VCC, the isolation element G can connect one end of the relay K to the second terminal of the sampling feedback circuit 122. With its first terminal grounded to GND and connected to one end 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 correctly. Furthermore, the sampling feedback circuit 122 connects one end of the relay K to the voltage sampling circuit 123; the voltage sampling circuit 123 samples the voltage at one end of the relay K and outputs a first sampled voltage to the microcontroller unit 11.

[0125] If the switching transistor Q1 is functioning normally, the drive signal can turn it on, grounding the first terminal of the isolation element G to GND, and also grounding the first terminal of the sampling feedback circuit 122 to GND. However, if the isolation element G malfunctions, it cannot connect one end of the relay K to the second terminal of the sampling feedback circuit 122; that is, the isolation element G disconnects the connection between one end of the relay K and the sampling feedback circuit 122. In this case, the sampling feedback circuit 122 outputs a self-test signal to the microcontroller unit 11, indicating a malfunction in the high-voltage sampling circuit 12. Simultaneously, the sampling feedback circuit 122 also cannot connect one end of the relay K to the voltage sampling circuit 123; therefore, the voltage sampling circuit 123 outputs an abnormal voltage to the microcontroller unit 11.

[0126] If the switching transistor Q1 malfunctions, the drive signal cannot turn it on, and the first terminal of the isolation element G is not grounded to GND. In this case, the isolation element G cannot function properly and cannot connect one end of the relay K to the second terminal of the sampling feedback circuit 122; that is, the isolation element G disconnects the connection between one end of the relay K and the sampling feedback circuit 122. Based on this, the sampling feedback circuit 122 outputs a self-test signal to the microcontroller unit 11, indicating that the high-voltage sampling circuit 12 is malfunctioning. Simultaneously, the sampling feedback circuit 122 also cannot connect one end of the relay K to the voltage sampling circuit 123; therefore, the voltage sampling circuit 123 outputs an abnormal voltage to the microcontroller unit 11.

[0127] The first resistor R1 can limit current, preventing excessive current from the drive signal from damaging the switching transistor Q1. The second resistor R2 can shunt the drive signal, reducing the current flowing into the control electrode of the switching transistor and protecting it. On the other hand, the second resistor R2 can also stabilize the voltage, i.e., the gate-source voltage of the switching transistor Q1 is stabilized based on the current flowing through the second resistor R2 and the resistance value of the second resistor R2.

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

[0129] In the above embodiments, the switching circuit includes a first resistor, a second resistor, and a switching transistor. When both the switching transistor and the isolation element are functioning normally, the switching transistor is turned on according to the drive signal output by the microcontroller unit, grounding the first terminal of the isolation element. The isolation element then connects one end of the relay to the sampling feedback circuit. In the event of a switch malfunction and / or an isolation element malfunction, the isolation element disconnects one end of the relay from the sampling feedback circuit. In the technical solution provided by this application, the switching transistor and the isolation element work together to drive the sampling feedback circuit for self-test feedback and to drive the voltage sampling circuit for voltage sampling, providing support for accurate fault location.

[0130] According to some embodiments of this application, refer to Figure 4 The sampling drive circuit 121 also includes multiple voltage divider 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 this embodiment, the sampling drive 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 through a 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 of the input isolation element G and reduce the current of the input isolation element G, thus protecting the isolation element G.

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

[0134] In the above embodiments, the sampling drive circuit also includes multiple voltage divider resistors. In the technical solution provided by this application embodiment, the current of the input isolation element can be reduced by using voltage divider resistors, which further reduces the current of the input sampling feedback circuit and the voltage sampling circuit, and can protect the sampling drive circuit, the sampling feedback circuit and the voltage sampling circuit.

[0135] According to some embodiments of this application, refer to Figure 5The sampling feedback circuit 122 includes a signal generator F and a signal receiver J. The first terminal of the signal generator F is connected to the sampling drive circuit 121, and the second terminal of the signal generator F is connected to the voltage sampling circuit 123. The first terminal of the signal receiver J is connected to the sampling drive circuit 121, the second terminal of the signal receiver J is connected to the microcontroller unit 11, and the third terminal 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 indicating that the high-voltage sampling circuit 12 is normal to the microcontroller unit 11. 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 indicating that the high-voltage sampling circuit 12 is abnormal to the microcontroller unit 11.

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

[0137] During the fault location process, the microcontroller unit 11 outputs a control signal to the relay K to control the relay K to conduct; the microcontroller unit 11 also outputs a drive signal to the first resistor R1, and the drive signal is transmitted to the control electrode of the switching transistor Q1 through the first resistor R1.

[0138] If both the switching transistor Q1 and the isolation element G are functioning correctly, one end of the relay K can be connected to the first terminal 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 then connects one end of the relay K 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. At this time, the self-test signal indicates that the high-voltage sampling circuit 12 is functioning correctly.

[0139] If the switching transistor Q1 or the isolation element G malfunctions, and the signal generator F is not connected to one end of the relay K, no feedback signal will be output. Since the signal receiver J does not receive a feedback signal, it outputs a self-test signal to the microcontroller unit 11. This self-test signal indicates a malfunction in the high-voltage sampling circuit 12. Because the signal generator F is not connected to one end of the relay K, the voltage sampling circuit 123 is also not connected to one end of the relay K, and therefore 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 using an infrared emitting tube. An infrared receiver is a device that can receive infrared signals and independently complete the process from infrared reception to outputting TTL frequency signals.

[0141] In the above embodiments, 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 microcontroller. 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 microcontroller. When the sampling drive circuit is abnormal, the signal generator cannot send a feedback signal, and the signal receiver, having not received a feedback signal, outputs a self-test signal indicating that the high-voltage sampling circuit is abnormal to the microcontroller. In the technical solution provided by this application, the signal generator and signal receiver cooperate to realize the feedback of the sampling circuit's self-test results, providing a basis for accurately locating the cause of the fault.

[0142] According to some embodiments of this application, refer 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 to GND.

[0143] In this embodiment, 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 microcontroller unit 11 outputs a control signal to the relay K to control the relay K to conduct; the microcontroller unit 11 also outputs a drive signal to the first resistor R1, and the drive signal is transmitted to the control electrode of the switching transistor Q1 through the first resistor R1.

[0145] If both the switching transistor Q1 and the isolation element G are functioning correctly, one end of the relay K can be connected to the first terminal 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 connects the other end of the relay K to the positive input terminal of the amplifier Op. Since the negative input terminal of the amplifier Op is connected to its output terminal, a voltage follower circuit is formed, meaning that the output voltage of the amplifier Op follows the input voltage at the positive input terminal of the amplifier Op. Because the positive input terminal of the amplifier Op is connected to one end of the relay K, the amplifier Op can follow the voltage at the first terminal of the relay K and output the followed voltage to the sampling chip X. The sampling chip X outputs a first sampling voltage to the microcontroller unit 11 based on the followed voltage.

[0146] If the switching transistor Q1 or the isolation element G malfunctions, the signal generator F will not be connected to one end of the relay K. In this case, the positive input terminal of the amplifier Op will also not be connected to one end of the relay K, so voltage following of one end of the relay K cannot be performed, and the sampling chip X will output an abnormal voltage to the microcontroller.

[0147] In the above embodiments, the voltage sampling circuit includes an amplifier, a sampling chip, and a filtering circuit. In the technical solution provided by this application embodiment, the amplifier and the sampling chip can sample the voltage at one end of the relay to obtain the sampled voltage, which provides a basis for judging whether the relay is normal based on the sampled voltage at both ends of the relay, thereby helping to locate the fault.

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

[0149] In this embodiment, 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 connected to the sampling feedback circuit 122, and the negative input terminal of the amplifier Op is connected to the output terminal of the amplifier Op and the sampling chip X.

[0150] During the fault location process, the microcontroller unit 11 outputs a control signal to the relay K to control the relay K to conduct; the microcontroller unit 11 also outputs a drive signal to the first resistor R1, and the drive signal is transmitted to the control electrode of the switching transistor Q1 through the first resistor R1.

[0151] If both the switching transistor Q1 and the isolation element G are functioning correctly, one end of the relay K can be connected to the first terminal 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 connects the other end of the relay K to the positive input terminal of the amplifier Op. Since the negative input terminal of the amplifier Op is connected to its output terminal, a voltage follower circuit is formed, meaning that the output voltage of the amplifier Op follows the input voltage at the positive input terminal of the amplifier Op. Because the positive input terminal of the amplifier Op is connected to one end of the relay K, the amplifier Op can follow the voltage at the first terminal of the relay K and output the followed voltage to the sampling chip X. The sampling chip X outputs a first sampling voltage to the microcontroller unit 11 based on the followed voltage.

[0152] If the switching transistor Q1 or the isolation element G malfunctions, the signal generator F will not be connected to one end of the relay K. In this case, the positive input terminal of the amplifier Op will also not be connected to one end of the relay K, so voltage following of one end of the relay K cannot be performed, and the sampling chip X will output an abnormal voltage to the microcontroller.

[0153] The first capacitor C1 mentioned above serves as an energy storage unit, stabilizing the input voltage at the positive input terminal of amplifier Op at the voltage across the first capacitor C1. The filter resistor R9 and the second capacitor C2 mentioned above serve as filters, reducing signal interference and ensuring the normal operation of amplifier Op.

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

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

[0156] In the above embodiments, 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 to follow 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 by this application embodiment, the amplifier and the sampling chip can sample the voltage at one terminal of the relay to obtain a first sampling voltage, which provides a basis for subsequently determining whether the relay is normal based on the first sampling voltage and the second sampling voltage, thereby helping to locate the fault.

[0157] According to some embodiments of this application, refer to Figure 8A fault location circuit is provided. The fault location circuit 10 includes a microcontroller unit 11 and two high-voltage sampling circuits 12 as described in the above embodiment. The two high-voltage sampling circuits 12 respectively sample the voltage across the two ends of the relay K. The microcontroller unit 11 obtains the 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 characterize whether each high-voltage sampling circuit 12 is normal and whether the relay is normal.

[0158] In this embodiment, 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 is connected to the load. After 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 supply power to 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 the two high-voltage sampling circuits 12 respectively. The two high-voltage sampling circuits 12 have the same internal structure. The difference between them is that one high-voltage sampling circuit 12 is connected to one end (one contact) of the relay K, and 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 to turn it on. The microcontroller unit 11 also outputs drive signals to the two high-voltage sampling circuits 12. Each high-voltage sampling circuit 12 receives the drive signals, performs a self-test based on the signals, and outputs a self-test signal indicating whether it is functioning correctly. Additionally, 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 sampling voltages. Then, the microcontroller unit 11 determines whether the corresponding high-voltage sampling circuit 12 is functioning correctly based on each self-test signal. If at least one high-voltage sampling circuit 12 is determined to be faulty, the microcontroller unit 11 directly outputs the fault location result for the sampling circuit.

[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 it 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 that both the sampling circuit and relay K are normal. In this case, other fault causes need to be investigated. 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 that the sampling circuit is normal but relay K is abnormal.

[0163] In the above embodiments, the high-voltage sampling circuit includes a microcontroller unit and two high-voltage sampling circuits. Each high-voltage sampling circuit can perform a self-test 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 functioning correctly based on the two self-test signals. If both high-voltage sampling circuits are functioning correctly, the microcontroller unit determines whether the relay is functioning correctly based on the two sampled voltages. Therefore, the technical solution provided in this application, through the cooperation between the microcontroller unit and the two high-voltage sampling circuits, can distinguish whether the fault lies in the sampling circuit or the relay itself, thereby accurately locating the cause of the relay's inability to conduct, and thus providing a basis for battery pack maintenance.

[0164] According to some embodiments of this application, refer to Figure 9 An electrical device is provided. The electrical device includes a relay, a battery, and a fault location circuit as described in the above embodiments.

[0165] In this embodiment, 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 supply power to 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 a self-test and sample the voltage at the first terminal of the relay, outputting a first self-test signal and a first sampling voltage. The second high-voltage sampling circuit can also perform a self-test and sample the voltage at the second terminal of the relay, outputting 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 whether the second high-voltage sampling circuit is normal based on the second self-test signal. If both the first and second high-voltage sampling circuits are normal, the microcontroller unit determines whether the relay is normal based on the first sampling voltage and the second sampling voltage.

[0167] The technical solution provided in this application can distinguish whether the fault is due to a sampling circuit malfunction or a relay malfunction, thereby accurately locating the cause of the relay's inability to conduct, and thus providing a basis for battery pack repair.

[0168] According to some embodiments of this application, refer to Figure 10 A fault location method is provided, and the method is illustrated by taking its application in 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 self-test through the first high-voltage sampling circuit and sample the voltage at the first terminal of the relay to obtain the first self-test signal and the first sampling voltage.

[0170] During fault location, the microcontroller sends a control signal to the relay to turn it on. The microcontroller also outputs a drive signal to the first high-voltage sampling circuit. The first high-voltage sampling circuit performs a self-test based on the drive signal and outputs a first self-test signal indicating whether it is functioning correctly. 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 self-test through the second high-voltage sampling circuit and sample the voltage at the second terminal of the relay to obtain the second self-test signal and the second sampling voltage.

[0172] The microcontroller outputs a drive signal to the second high-voltage sampling circuit. The second high-voltage sampling circuit performs a self-test based on the drive signal and outputs a second self-test signal indicating whether it is functioning correctly. In addition, the second high-voltage sampling circuit also samples the voltage at the second terminal of the relay and outputs a second sampling voltage.

[0173] Step 203: The microcontroller obtains the 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 characterize whether the sampling circuit is normal and whether the relay is normal.

[0174] The microcontroller receives a first self-test signal, a second self-test signal, a first sampling voltage, and a second sampling voltage. Then, the microcontroller determines whether the high-voltage sampling circuit is functioning correctly based on the first self-test signal, and whether the second high-voltage sampling circuit is functioning correctly 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 faulty, the microcontroller directly outputs the fault location result for the sampling circuit malfunction.

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

[0176] In the above embodiments, a first high-voltage sampling circuit performs a self-test and samples the voltage at the first terminal 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 at the second terminal of the relay to obtain a second self-test signal and a second sampling voltage; the microcontroller unit obtains the 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 characterize whether the sampling circuit and the relay are functioning correctly. In the technical solution provided by this application embodiment, the microcontroller unit, the first high-voltage sampling circuit, and the second high-voltage sampling circuit cooperate to realize the self-test of the sampling circuit and the voltage sampling at both ends of the relay. Based on the self-test results and the sampling voltage, it is possible to accurately determine whether the relay's inability to conduct is caused by an abnormality in the sampling circuit or by an abnormality in the relay itself, thus accurately locating the cause of the fault and providing a basis for battery pack maintenance.

[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 and sampling the voltage at the first terminal of the relay through the first high-voltage sampling circuit to obtain a first self-test signal and a first sampling voltage includes:

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

[0179] In one case, refer to Figure 11 The process includes receiving a drive signal from the microcontroller via a sampling drive circuit, outputting a first self-test signal indicating whether the first high-voltage sampling circuit is functioning correctly to the microcontroller via a sampling feedback circuit, and outputting a first sampling voltage to the microcontroller via a voltage sampling circuit. This process may include the following steps:

[0180] Step 301: Receive the drive signal output by the microcontroller through the sampling drive circuit, and connect the first terminal of the relay with the sampling feedback circuit.

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

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

[0183] Step 302: The sampling feedback circuit outputs a first self-test signal indicating that the first high-voltage sampling circuit is normal to the microcontroller unit, and connects the first terminal of the relay to the voltage sampling circuit.

[0184] After the sampling feedback circuit is connected to the first terminal of the relay, it 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 normally. Furthermore, the sampling feedback circuit connects the first terminal of the relay to the voltage sampling circuit.

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

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

[0187] After the voltage sampling circuit is connected to the first terminal of the relay, it samples the voltage at the first terminal of the relay and outputs the first sampled voltage to the microcontroller unit.

[0188] In the above embodiments, the sampling drive circuit receives the drive signal output by the microcontroller unit and connects 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 and connects the first terminal of the relay to the voltage sampling circuit; the voltage sampling circuit outputs a first sampling voltage to the microcontroller unit. In the technical solution provided by this application, the sampling drive circuit, sampling feedback circuit, and voltage sampling circuit cooperate to achieve self-testing of the high-voltage sampling circuit and voltage sampling at the first terminal of the relay, providing a basis for accurately locating the cause of the fault.

[0189] According to some embodiments of this application, the sampling drive circuit includes a switching circuit and an isolation element. In the above embodiments, "receiving the drive signal output by the microcontroller through the sampling drive circuit and turning on the connection between the first terminal of the relay and the sampling feedback circuit" may include: when the relay is turned on according to the drive signal output by the microcontroller, the switching circuit grounds the first terminal of the isolation element, and the isolation element turns on the connection between the first terminal of the relay and the sampling feedback circuit.

[0190] During the fault location process, the microcontroller outputs a control signal to the relay to control the relay to conduct; the microcontroller also outputs a drive signal to the first resistor, and the drive signal is transmitted to the control electrode of the switching transistor through the first resistor.

[0191] If the switching circuit is normal, the first terminal of the isolation element is grounded, and the first terminal of the sampling feedback circuit is also grounded. If the isolation element is normal, the first terminal of the relay can be connected to the second terminal of the sampling feedback circuit. With the first terminal of the sampling feedback circuit grounded and the second terminal of the sampling feedback circuit connected to the first terminal of the relay, the sampling feedback circuit outputs a first self-test signal to the microcontroller unit. This first self-test signal indicates that the first high-voltage sampling circuit is normal. Furthermore, the sampling feedback circuit connects the first terminal of the relay to the voltage sampling circuit, which samples the voltage at the first terminal of the relay and outputs a first sampled voltage to the microcontroller unit.

[0192] In the above embodiments, when the drive signal output by the microcontroller unit is turned on, the switching circuit grounds the first terminal of the isolation element, and the isolation element connects the first terminal of the relay to the sampling feedback circuit. In the technical solution provided by this application, the switching transistor and the isolation element work together 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 accurately locating the cause of the fault.

[0193] According to some embodiments of this application, refer 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 characterizing the normal operation of the first high-voltage sampling circuit to the microcontroller through the sampling feedback circuit, and connecting the first terminal of the relay with the voltage sampling circuit" may include the following steps:

[0194] Step 401: After connecting to the first terminal of the relay, the signal generator turns on the connection between the voltage sampling circuit and the first terminal 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 conduct; the microcontroller also outputs a drive signal to the first resistor, and the drive signal is transmitted to the control electrode of the switching transistor through the first resistor.

[0196] If the switching transistor and isolation components are functioning correctly, the first terminal of the relay can be connected to the first terminal of the signal generator. After the signal generator is connected to the first terminal of the relay, it outputs a feedback signal, and then connects the first terminal of the relay to the voltage sampling circuit.

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

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

[0199] In the above embodiments, after being connected to the first terminal of the relay, the signal generator conducts the connection between the voltage sampling circuit and the first terminal of the relay and outputs a feedback signal; the feedback signal is received by the signal receiver, and a first self-test signal is output to the microcontroller unit. In the technical solution provided by this application embodiment, the signal generator and the signal receiver cooperate to realize self-test feedback, which provides support for judging whether the sampling circuit is normal and can help accurately locate the cause of the fault.

[0200] According to some embodiments of this application, refer 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 microcontroller unit through the voltage sampling circuit" may include the following steps:

[0201] Step 501: The voltage at the first terminal of the relay is followed by an amplifier, and the following voltage is output.

[0202] During the fault location process, the microcontroller outputs a control signal to the relay to control the relay to conduct; the microcontroller also outputs a drive signal to the first resistor, and the drive signal is transmitted to the control electrode of the switching transistor through the first resistor.

[0203] If the switching transistor and isolation components are functioning correctly, the first terminal of the relay can be connected to the first terminal of the signal generator. After the signal generator is connected to the first terminal of the relay, it outputs a feedback signal and connects the first terminal of the relay to the positive input terminal of the amplifier. Since the negative input terminal of the amplifier is connected to the output terminal, a voltage follower circuit is formed, meaning the amplifier's output voltage follows the input voltage at the positive input terminal. In this way, the amplifier performs voltage following on the first terminal of the relay and inputs the followed voltage to the sampling chip.

[0204] Step 502: The following voltage is sampled by the sampling chip and the first sampled voltage is output to the microcontroller unit.

[0205] The sampling chip samples the following voltage and outputs the first sampled voltage to the microcontroller unit.

[0206] In the above embodiments, the voltage at the first terminal of the relay is followed by an amplifier, and a following voltage is output. The following voltage is sampled by a sampling chip, and a first sampled voltage is output to the microcontroller unit. In the technical solution provided by this application embodiment, the amplifier forms a following circuit, which can follow the voltage at the first terminal of the relay. This allows the sampling chip to sample the voltage at the first terminal of the relay to obtain a first sampled voltage, providing support for subsequent judgment of whether the relay is normal based on the first sampled voltage, and helping to accurately locate the cause of the fault.

[0207] In another case, according to some embodiments of this application, refer to Figure 14The process includes receiving a drive signal from the microcontroller via a sampling drive circuit, outputting a first self-test signal indicating whether the first high-voltage sampling circuit is functioning correctly to the microcontroller via a sampling feedback circuit, and outputting a first sampling voltage to the microcontroller via a voltage sampling circuit. This process may include the following steps:

[0208] Step 601: Receive the drive signal through the sampling drive circuit and disconnect the connection between the first terminal of the relay and the sampling feedback circuit.

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

[0210] In the event of an abnormality in the sampling drive circuit, after receiving the drive signal, the sampling drive circuit cannot connect the first terminal of the relay to the sampling feedback circuit, that is, it disconnects the connection between the first terminal of the relay and the sampling feedback circuit.

[0211] Step 602: Output a first self-test signal, representing an abnormality in the first high-voltage sampling circuit, to the microcontroller unit through the sampling feedback circuit.

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

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

[0214] Because the sampling feedback circuit is disconnected from the first terminal of the relay, the voltage sampling circuit is also disconnected from the first terminal of the relay. In this situation, the first sampled voltage output by the voltage sampling circuit to the microcontroller unit is an abnormal voltage.

[0215] In the above embodiments, a driving signal is received through a sampling driving circuit, disconnecting the connection between the first terminal of the relay and 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 through the sampling feedback circuit; and a first sampling voltage is output to the microcontroller unit through the voltage sampling circuit. In the technical solution provided by this application, the sampling driving circuit, sampling feedback circuit, and voltage sampling circuit cooperate to achieve self-testing of the high-voltage sampling circuit and voltage sampling at the first terminal of the relay, providing a basis for accurately locating the cause of the fault.

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

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

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

[0219] It should be understood that although the steps in the flowcharts of the embodiments described above are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the embodiments described above may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the steps or stages in other steps. It is understood that the steps in different embodiments can be freely combined as needed, and all non-contradictory solutions formed by such combinations are within the scope of protection of this application.

[0220] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above 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 merely illustrate several implementation methods of this application to facilitate a detailed understanding of the technical solutions of this application, but should not be construed as limiting the scope of protection of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the scope of protection of this application. It should be understood that technical solutions obtained by those skilled in the art based on the technical solutions provided in this application through logical analysis, reasoning, or limited experimentation are all within the scope of protection of the appended claims. Therefore, the scope of protection of this patent application should be determined by the content of the appended claims, and the specification 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 microcontroller 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 acquire 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 circuit according to the drive signal output by the microcontroller unit; The sampling feedback circuit is also connected to the voltage sampling circuit and is used to output a self-test signal to the microcontroller unit; wherein, the self-test signal is used to characterize whether the high-voltage sampling circuit is normal. The sampling drive circuit includes a switching circuit and an isolation element; The first terminal of the switching circuit is connected to the microcontroller unit, and the second terminal of the switching circuit is connected to the first terminal of the isolation element and the first terminal 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 terminal. The sampling drive circuit also includes multiple voltage divider resistors, which 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.

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 connects one end of the relay to the sampling feedback circuit, and the sampling feedback circuit connects one end of the relay to the voltage sampling circuit, and the sampling voltage is the voltage at one end of the relay. When the self-test signal indicates an abnormality in the high-voltage sampling circuit, the sampling drive circuit disconnects one end of the relay from the sampling feedback circuit, and the sampling voltage becomes an abnormal voltage.

3. The high-voltage sampling circuit according to claim 2, characterized in that, The switching circuit is turned on according to the drive signal output by the microcontroller unit, grounding the first terminal of the isolation element; the isolation element connects one terminal of the relay to 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 switching circuit includes a first resistor, a second resistor, and a switching transistor; The first end of the first resistor is connected to the microcontroller 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 switching transistor, respectively. The second terminal of the second resistor is grounded; The first terminal of the switching transistor is connected to the first terminal of the isolation element and the first terminal of the sampling feedback circuit, respectively.

5. 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 terminal of the signal generator is connected to the sampling drive circuit, and the second terminal 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 microcontroller unit, and the third end of the signal receiver is connected to the first power supply terminal. If the sampling drive circuit connects the signal generator to one end of the relay, the signal generator connects the voltage sampling circuit to 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 microcontroller. If the sampling drive circuit fails to connect the signal generator to one end of the relay, the signal receiver will output a self-test signal indicating an abnormality in the high-voltage sampling circuit to the microcontroller unit.

6. The high-voltage sampling circuit according to claim 2, characterized in that, The voltage sampling circuit includes an amplifier, a sampling chip, and a filtering 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.

7. The high-voltage sampling circuit according to claim 6, 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 terminal of the filter resistor, the first terminal of the first capacitor, and the first terminal of the second capacitor, respectively. The second terminal of the filter resistor is connected to the second terminal of the second capacitor and the sampling chip, respectively. The second terminal of the first capacitor is grounded.

8. A fault location circuit, characterized in that, The fault location circuit includes a microcontroller and two high-voltage sampling circuits as described in any one of claims 1-7; The two high-voltage sampling circuits respectively sample the voltage across the two ends of the relay; The microcontroller unit obtains the 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 characterize whether each of the high-voltage sampling circuits is normal and whether the relay is normal.

9. An electrical appliance, characterized in that, The electrical equipment includes a relay, a battery, and a fault location circuit as described in claim 8.

10. A fault location method, characterized in that, Applied to the fault location circuit as described in claim 8, the fault location circuit includes a microcontroller unit, a first high-voltage sampling circuit, and a second high-voltage sampling circuit; the method includes: The first high-voltage sampling circuit performs a self-test and samples the voltage at the first terminal of the relay to obtain a first self-test signal and a first sampling voltage. The second high-voltage sampling circuit performs a self-test and samples the voltage at the second terminal of the relay to obtain a second self-test signal and a second sampling voltage. The microcontroller unit obtains the 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 characterize whether the sampling circuit is normal and whether the relay is normal.

11. The method according to claim 10, characterized in that, The first high-voltage sampling circuit includes a sampling drive circuit, a sampling feedback circuit, and a voltage sampling circuit; the step of performing self-testing through the first high-voltage sampling circuit and sampling the voltage at the first terminal of the relay to obtain a first self-test signal and a first sampling voltage includes: The sampling drive circuit receives the drive signal output by the microcontroller unit, the sampling feedback circuit outputs a first self-test signal to the microcontroller unit indicating whether the first high-voltage sampling circuit is normal, and the voltage sampling circuit outputs the first sampling voltage to the microcontroller unit.

12. The method according to claim 11, characterized in that, The steps include receiving the drive signal output by the microcontroller through the sampling drive circuit, outputting a first self-test signal indicating whether the first high-voltage sampling circuit is normal to the microcontroller through the sampling feedback circuit, and outputting the first sampling voltage to the microcontroller through the voltage sampling circuit, including: The sampling drive circuit receives the drive signal output by the microcontroller unit and connects the first terminal of the relay to the sampling feedback circuit. The sampling feedback circuit outputs a first self-test signal indicating that the first high-voltage sampling circuit is normal to the microcontroller, and connects the first terminal of the relay to the voltage sampling circuit. The voltage sampling circuit outputs the first sampled voltage to the microcontroller unit; wherein the first sampled voltage is the voltage at the first terminal of the relay.

13. The method according to claim 12, characterized in that, The step of receiving the drive signal output by the microcontroller through the sampling drive circuit and connecting the first terminal of the relay with the sampling feedback circuit includes: When the drive signal output by the microcontroller is turned on, the switching circuit grounds the isolation element, which in turn connects the first terminal of the relay to the sampling feedback circuit.

14. The method according to claim 11, characterized in that, The sampling feedback circuit includes a signal generator and a signal receiver. The step of outputting a first self-test signal indicating that the first high-voltage sampling circuit is normal to the microcontroller through the sampling feedback circuit, and connecting the first terminal of the relay to the voltage sampling circuit, includes: After being connected to the first terminal of the relay, the signal generator activates the connection between the voltage sampling circuit and the first terminal 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 microcontroller unit.

15. The method according to claim 11, characterized in that, The voltage sampling circuit includes an amplifier and a sampling chip; the step of outputting the first sampled voltage to the microcontroller unit through the voltage sampling circuit includes: The amplifier tracks the voltage at the first terminal of the relay and outputs a tracking voltage. The sampling chip samples the following voltage and outputs the first sampled voltage to the microcontroller unit.

16. The method according to claim 11, characterized in that, The steps include receiving the drive signal output by the microcontroller through the sampling drive circuit, outputting a first self-test signal indicating whether the first high-voltage sampling circuit is normal to the microcontroller through the sampling feedback circuit, and outputting the first sampling voltage to the microcontroller through the voltage sampling circuit, including: The sampling drive circuit receives a drive signal and disconnects the connection between the first terminal of the relay and the sampling feedback circuit. The sampling feedback circuit outputs a first self-test signal, representing an abnormality in the first high-voltage sampling circuit, to the microcontroller unit. The voltage sampling circuit outputs the first sampled voltage to the microcontroller unit; wherein the first sampled voltage is an abnormal voltage.

17. The method according to claim 16, characterized in that, The sampling feedback circuit includes a signal generator and a signal receiver. The step of outputting a first self-test signal, indicating an abnormality in the first high-voltage sampling circuit, to the microcontroller unit via the sampling feedback circuit includes: 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.

Images