Direct current system ground fault detection device and system

Abstract

The utility model discloses a DC system ground fault detection device and system, the DC system ground fault detection device is used for being connected with a grounded bus in a DC system, and the DC system ground fault detection device comprises a main control unit, a current detection unit, a voltage detection unit and an excitation signal generation unit; the current detection unit, the voltage detection unit and the excitation signal generation unit are connected with the main control unit; the current detection unit, the voltage detection unit and the excitation signal generation unit are connected with a bus; wherein the excitation signal generation unit comprises at least two stages of signal amplification circuits. The method can be widely applied to the technical field of grounding test.

Description

Technical Field

[0001] This application relates to the field of grounding test technology, and in particular to a grounding fault detection device and system for DC systems. Background Technology

[0002] In related technologies, existing DC system grounding fault detection devices include voltage acquisition units and current acquisition units. These units can acquire the voltage and current of the grounded bus to determine whether a DC system grounding fault has occurred. However, because the voltage and current of the bus fluctuate significantly during a grounding fault, low voltage and current levels directly affect the testing accuracy of the DC system grounding fault detection device. Therefore, there are still technical problems that need to be solved in these related technologies. Utility Model Content

[0003] The purpose of this application is to at least partially solve one of the technical problems existing in the prior art.

[0004] Therefore, one objective of this application is to provide a DC system grounding fault detection device and a semiconductor device, which can improve the testing accuracy.

[0005] To achieve the above-mentioned technical objectives, the technical solution adopted in the embodiments of this application includes: a DC system grounding fault detection device, used to connect to a grounded bus in a DC system, the device comprising:

[0006] The system includes a main control unit, a current detection unit, a voltage detection unit, and an excitation signal generation unit.

[0007] The current detection unit, the voltage detection unit, and the excitation signal generation unit are connected to the main control unit;

[0008] The current detection unit, the voltage detection unit, and the excitation signal generation unit are connected to the bus; wherein the excitation signal generation unit includes at least two stages of signal amplification circuit.

[0009] In addition, the DC system grounding fault detection device according to the above embodiments of this utility model may also have the following additional technical features:

[0010] Furthermore, in this embodiment of the application, the excitation signal generating unit includes a first signal amplification circuit and a second signal amplification circuit; the first signal amplification circuit is connected to the main control unit; the first signal amplification circuit and the bus are connected to the second signal amplification circuit.

[0011] Furthermore, in this embodiment of the application, the first signal amplification circuit includes a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a first capacitor, a second capacitor, a third capacitor, a fourth capacitor, a fifth capacitor, a sixth capacitor, a first chip, and a first inductor.

[0012] One end of the first resistor is connected to the main control unit; the other end of the first resistor is connected to one end of the second resistor; the other end of the second resistor and one end of the third capacitor are connected to the third pin of the first chip; one end of the third resistor is connected to the first power supply; one end of the fourth resistor and one end of the fifth resistor are connected to the other end of the third resistor; one end of the fourth resistor and one end of the second capacitor are connected to the second pin of the first chip; one end of the first capacitor and one end of the first inductor are connected to the first pin of the first chip; one end of the fourth capacitor is connected to the eighth pin of the first chip; one end of the fifth capacitor is connected to the seventh pin of the first chip; one end of the sixth capacitor is connected to the sixth pin of the first chip.

[0013] The other ends of the first capacitor, the second capacitor, the third capacitor, and the fifth resistor are connected to the first ground line; the other ends of the fifth capacitor, the sixth capacitor, and the fifth pin of the first chip are connected to the second ground line; the other ends of the first inductor and the eighth pin of the first chip are connected to the second power supply; the other end of the fourth capacitor is connected to the third power supply.

[0014] The sixth pin of the first chip is connected to the second signal amplifier circuit as the first output terminal of the first signal amplifier circuit, and the seventh pin of the first chip is connected to the second signal amplifier circuit as the second output terminal of the first signal amplifier circuit.

[0015] Furthermore, in this embodiment, the second signal amplification circuit includes a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor, a tenth resistor, an eleventh resistor, a twelfth resistor, a seventh capacitor, a first diode, a second diode, a third diode, a fourth diode, a first transistor, a second transistor, and a second chip.

[0016] One end of the seventh resistor is connected to the second output terminal of the first signal amplifier circuit, and one end of the eighth resistor is connected to the first output terminal of the first signal amplifier circuit; one end of the sixth resistor and the other end of the seventh resistor are connected to the positive input terminal of the second chip; the other end of the sixth resistor is connected to the third power supply; one end of the ninth resistor, one end of the seventh capacitor, and the other end of the eighth resistor are connected to the negative input terminal of the second chip; one end of the tenth resistor is connected to the output terminal of the second chip; the tenth resistor, the cathode of the first diode, and the cathode of the second diode are connected; the cathode of the first diode and one end of the eleventh resistor are connected to the base of the first transistor; the emitter of the first transistor is connected to the emitter of the second transistor; one end of the twelfth resistor and the anode of the second diode are connected to the base of the second transistor; the anode of the third diode is connected to the cathode of the fourth diode.

[0017] The other end of the eleventh resistor, the collector of the first transistor, the cathode of the third diode, and the first power supply terminal of the second chip are connected to the fourth power supply; the other end of the twelfth resistor, the collector of the second transistor, the anode of the fourth diode, and the second power supply terminal of the second chip are connected to the fifth power supply; the other end of the ninth resistor and the other end of the seventh capacitor are connected to the emitter of the first transistor; the emitter of the first transistor is connected to the bus as the output terminal of the second signal amplification circuit.

[0018] Furthermore, in this embodiment, the current detection unit includes a third amplification circuit and a fourth amplification circuit; the third amplification circuit is connected to the bus; the third amplification circuit is connected to the main control unit and the fourth amplification circuit.

[0019] Furthermore, in this embodiment of the application, the third amplification circuit includes a thirteenth resistor, a fourteenth resistor, a fifteenth resistor, a sixteenth resistor, an eighth capacitor, a ninth capacitor, and a third chip;

[0020] One end of the thirteenth resistor, one end of the eighth capacitor, and the busbar are connected to the negative input terminal of the third chip; one end of the thirteenth resistor, one end of the eighth capacitor, and one end of the sixteenth resistor are connected to the output terminal of the third chip; the other end of the sixteenth resistor serves as the output terminal of the third amplifier circuit.

[0021] One end of the fourteenth resistor and one end of the fifteenth resistor are connected to the positive input terminal of the third chip;

[0022] One end of the ninth capacitor and the first power supply terminal of the third chip are connected to the sixth power supply.

[0023] The other end of the fourteenth resistor is connected to the first power supply; the other end of the fifteenth resistor, the other end of the ninth capacitor, and the second power supply terminal of the third chip are all grounded.

[0024] Furthermore, in this embodiment of the application, the fourth amplification circuit includes a seventeenth resistor, an eighteenth resistor, a nineteenth resistor, a twentieth resistor, a tenth capacitor, an eleventh capacitor, a twelfth capacitor, and a fourth chip;

[0025] One end of the seventeenth resistor, one end of the tenth capacitor, and the output terminal of the third amplifier circuit are connected to the negative input terminal of the fourth chip; one end of the seventeenth resistor, one end of the tenth capacitor, and one end of the twentieth resistor are connected to the output terminal of the fourth chip; the other end of the twentieth resistor is connected to one end of the twelfth capacitor; the other end of the twentieth resistor serves as the output terminal of the fourth amplifier circuit.

[0026] One end of the eighteenth resistor, one end of the nineteenth resistor, and one end of the eleventh capacitor are connected to the positive input terminal of the fourth chip;

[0027] The other end of the eighteenth resistor is connected to the main control unit; the other end of the nineteenth resistor, the other end of the eleventh capacitor, the other end of the twelfth capacitor, and the second power supply terminal of the fourth chip are all grounded.

[0028] Furthermore, in the embodiments of this application, the main control unit includes one or more STM32 series microcontrollers.

[0029] Furthermore, in this embodiment, the voltage detection unit includes a voltage acquisition circuit and a voltage amplification circuit; the voltage acquisition circuit and the main control unit are connected to the voltage amplification circuit.

[0030] On the other hand, embodiments of this application also provide a DC system grounding fault location system, including the DC system grounding fault detection device described in any of the preceding claims.

[0031] The advantages and beneficial effects of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application:

[0032] This application can generate a signal after a bus grounding fault by adding an excitation signal generation unit including a two-stage signal amplification circuit. This signal can then be detected to determine whether a bus grounding fault has occurred. This reduces the impact of voltage and current fluctuations during a grounding fault on the detection results and improves test accuracy. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the structure of a DC system grounding fault detection device in a specific embodiment of the present invention;

[0034] Figure 2 This is a schematic diagram of the structure of a DC system grounding fault detection device in another specific embodiment of the present invention;

[0035] Figure 3 This is a schematic diagram of the structure of a DC system grounding fault detection device in another specific embodiment of the present invention;

[0036] Figure 4 This is a schematic diagram of the structure of a DC system grounding fault detection device in another specific embodiment of the present invention;

[0037] Figure 5 This is a schematic diagram of the voltage acquisition circuit in the voltage detection unit of this utility model;

[0038] Figure 6 This is a schematic diagram of the voltage amplification circuit in the voltage detection unit of this utility model. Detailed Implementation

[0039] The following detailed description, in conjunction with the accompanying drawings, illustrates the principle and process of the DC system grounding fault detection device according to the present invention.

[0040] Reference Figure 1 This application provides a grounding fault detection device for a DC system. (Refer to...) Figure 2 This DC system grounding fault detection device can be used to connect to a grounded bus in a DC system. The device may include at least a main control unit 1, a current detection unit 2, a voltage detection unit 3, and an excitation signal generation unit 4; the current detection unit 2, voltage detection unit 3, and excitation signal generation unit 4 can be connected to the main control unit 1; the current detection unit 2, voltage detection unit 3, and excitation signal generation unit 4 can be connected to the bus; wherein the excitation signal generation unit 4 may include at least two stages of signal amplification circuitry.

[0041] Furthermore, in this embodiment of the application, the excitation signal generating unit 4 may include a first signal amplification circuit 41 and a second signal amplification circuit 42; the first signal amplification circuit 41 may be connected to the main control unit 1; the first signal amplification circuit 41 and the bus may be connected to the second signal amplification circuit 42.

[0042] Furthermore, referring to Figure 3In this embodiment of the application, the first signal amplification circuit 41 may include a first resistor R88, a second resistor R92, a third resistor R87, a fourth resistor R99, a fifth resistor R96, a first capacitor C99, a second capacitor C104, a third capacitor C105, a fourth capacitor C100, a fifth capacitor C102, a sixth capacitor C103, a first chip U15, and a first inductor L23.

[0043] One end of the first resistor R88 can be connected to the main control unit 1; the other end of the first resistor R88 can be connected to one end of the second resistor R92; the other end of the second resistor R92 and one end of the third capacitor C105 can be connected to the third pin of the first chip U15; one end of the third resistor R87 can be connected to the first power supply 2.5V; one end of the fourth resistor R99 and one end of the fifth resistor R96 can be connected to the other end of the third resistor R87; one end of the fourth resistor R99 and one end of the second capacitor C104 can be connected to the second pin of the first chip U15; one end of the first capacitor C99 and one end of the first inductor L23 can be connected to the first pin of the first chip U15; one end of the fourth capacitor C100 can be connected to the eighth pin of the first chip U15; one end of the fifth capacitor C102 can be connected to the seventh pin of the first chip U15; one end of the sixth capacitor C103 can be connected to the sixth pin of the first chip U15.

[0044] The other ends of the first capacitor C99, the second capacitor C104, the third capacitor C105, and the fifth resistor R96 can be connected to the first ground line; the other ends of the fifth capacitor C102, the sixth capacitor C103, and the fifth pin of the first chip U15 can be connected to the second ground line; the other ends of the first inductor L23 and the eighth pin of the first chip U15 can be connected to the second power supply VCC1; the other end of the fourth capacitor C100 can be connected to the third power supply RAD T11.

[0045] The sixth pin of the first chip U15 serves as the first output terminal of the first signal amplifier circuit 41 and can be connected to the second signal amplifier circuit 42. The seventh pin of the first chip U15 serves as the second output terminal of the first signal amplifier circuit 41 and can be connected to the second signal amplifier circuit 42.

[0046] Furthermore, referring to Figure 3 In this embodiment of the application, the second signal amplification circuit 42 may include a sixth resistor R80, a seventh resistor R90, an eighth resistor R93, a ninth resistor R102, a tenth resistor R91, an eleventh resistor R81, a twelfth resistor R99, a seventh capacitor C109, a first diode D13, a second diode D14, a third diode D15, a fourth diode D16, a first transistor T1, a second transistor T2, and a second chip U16;

[0047] One end of the seventh resistor R90 can be connected to the second output terminal of the first signal amplifier circuit 41; one end of the eighth resistor R93 can be connected to the first output terminal of the first signal amplifier circuit 41; one end of the sixth resistor R80 and the other end of the seventh resistor R90 can be connected to the positive input terminal of the second chip U16; the other end of the sixth resistor R80 can be connected to the third power supply RAD. T11 is connected; one end of the ninth resistor R102, one end of the seventh capacitor C109, and the other end of the eighth resistor R93 can be connected to the negative input terminal of the second chip U16; one end of the tenth resistor R91 can be connected to the output terminal of the second chip U16; the tenth resistor R91 and the cathode of the first diode D13 can be connected to the cathode of the second diode D14; the cathode of the first diode D13 and one end of the eleventh resistor R81 can be connected to the base of the first transistor T1; the emitter of the first transistor T1 can be connected to the emitter of the second transistor T2; one end of the twelfth resistor R99 and the anode of the second diode D14 can be connected to the base of the second transistor T2; the anode of the third diode D15 can be connected to the cathode of the fourth diode D16.

[0048] The other end of the eleventh resistor R81, the collector of the first transistor T1, the cathode of the third diode D15, and the first power supply terminal of the second chip U16 can be connected to the fourth power supply T11+; the other end of the twelfth resistor R99, the collector of the second transistor T2, the anode of the fourth diode D16, and the second power supply terminal of the second chip U16 can be connected to the fifth power supply T11-; the other end of the ninth resistor R102 and the other end of the seventh capacitor C109 can be connected to the emitter of the first transistor T1; the emitter of the first transistor T1, as the output terminal of the second signal amplifier circuit 42, can be connected to the bus.

[0049] Furthermore, in this embodiment, the current detection unit 2 may include a third amplifier circuit 21 and a fourth amplifier circuit 22; the third amplifier circuit 21 may be connected to the bus; the third amplifier circuit 21 may be connected to the main control unit 1 and the fourth amplifier circuit 22.

[0050] Furthermore, in the embodiments of this application, reference is made to Figure 4 The third amplifier circuit 21 may include a thirteenth resistor R16, a fourteenth resistor R24, a fifteenth resistor R25, a sixteenth resistor R19, an eighth capacitor C31, a ninth capacitor C36, and a third chip U4A.

[0051] One end of the thirteenth resistor R16, one end of the eighth capacitor C31, and the bus can be connected to the negative input terminal of the third chip U4A; one end of the thirteenth resistor R16, one end of the eighth capacitor C31, and one end of the sixteenth resistor R19 can be connected to the output terminal of the third chip U4A; the other end of the sixteenth resistor R19 serves as the output terminal of the third amplifier circuit 21.

[0052] One end of the fourteenth resistor R24 ​​and one end of the fifteenth resistor R25 can be connected to the positive input terminal of the third chip U4A;

[0053] One end of the ninth capacitor C36 and the first power supply terminal of the third chip U4A can be connected to the sixth power supply 3.3V;

[0054] The other end of the fourteenth resistor R24 ​​can be connected to the first power supply 2.5V; the other end of the fifteenth resistor R25, the other end of the ninth capacitor C36, and the second power supply terminal of the third chip U4A are all grounded.

[0055] Furthermore, in the embodiments of this application, reference is made to Figure 4 The fourth amplifier circuit 22 may include the seventeenth resistor R18, the eighteenth resistor R22, the nineteenth resistor R23, the twentieth resistor R20, the tenth capacitor C33, the eleventh capacitor C35, the twelfth capacitor C34, and the fourth chip U4B.

[0056] One end of the seventeenth resistor R18, one end of the tenth capacitor C33, and the output of the third amplifier circuit 21 can be connected to the negative input of the fourth chip U4B; one end of the seventeenth resistor R18, one end of the tenth capacitor C33, and one end of the twentieth resistor R20 can be connected to the output of the fourth chip U4B; the other end of the twentieth resistor R20 can be connected to one end of the twelfth capacitor C34; the other end of the twentieth resistor R20 serves as the output of the fourth amplifier circuit 22.

[0057] One end of the eighteenth resistor R22, one end of the nineteenth resistor R23, and one end of the eleventh capacitor C35 can be connected to the positive input terminal of the fourth chip U4B.

[0058] The other end of the eighteenth resistor R22 can be connected to the main control unit 1; the other end of the nineteenth resistor R23, the other end of the eleventh capacitor C35, the other end of the twelfth capacitor C34, and the second power supply terminal of the fourth chip U4B are all grounded.

[0059] Furthermore, in the embodiments of this application, the main control unit 1 may include one or more STM32 series microcontrollers.

[0060] Furthermore, in the embodiments of this application, reference is made to Figure 5 as well as Figure 6The voltage detection unit 3 may include a voltage acquisition circuit and a voltage amplification circuit; the voltage acquisition circuit and the main control unit 1 may be connected to the voltage amplification circuit.

[0061] The specific calculation principle of this application is explained below with reference to the accompanying drawings:

[0062] In this embodiment, to locate a DC ground fault, a signal source is first used to test the insulation status of the DC system. If no ground fault is found, the ground fault investigation can be completed. If a ground fault is found, after the signal source completes the characteristic signal loading, a single detector can be used to locate the ground fault (or multiple detectors can be used simultaneously to measure different lines—improving the search efficiency). In single-detector mode, the ground fault can be located and resolved, and the ground fault can also be resolved. If the single detector cannot find the ground fault, it is necessary to determine whether the characteristic signal indicates a branch reporting a ground fault and the search signal is gradually weakening or whether there is no branch indicating a ground fault. First, set the multi-detector to online working mode and pair addresses. For cases where the branch reporting a ground fault signal disappears, use multiple detectors to test different ground faults on the branch simultaneously and analyze the ground fault situation in the interval based on the differential signal. For cases where there are no branch reporting a ground fault, use multiple detectors to test simultaneously in the same direction on the branch with a characteristic signal trend, so that the signal is superimposed and amplified, and the high impedance insulation decrease is found.

[0063] Furthermore, embodiments of this application also provide a DC system ground fault location system. This system may include any of the DC system ground fault detection devices described above.

[0064] It should be noted that the contents of the above-described DC system grounding fault detection device embodiments are all applicable to this semiconductor device embodiment. The specific functions implemented by this semiconductor device embodiment are the same as those of the above-described DC system grounding fault detection device embodiments, and the beneficial effects achieved are also the same as those achieved by the above-described DC system grounding fault detection device embodiments.

[0065] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the term "switching" should be interpreted broadly, for example, it can mean transformation or conversion; for those skilled in the art, the specific meaning of the above term in this utility model can be understood according to the specific circumstances.

[0066] In this specification, the description of referenced terms refers to a specific structure or feature described in connection with an embodiment or example that is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0067] Although embodiments of the present invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the claims and their equivalents.

[0068] The above is a detailed description of the preferred embodiments of this application, but this application is not limited to the embodiments described. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of this application, and these equivalent modifications or substitutions are all included within the scope defined by the claims of this application.

Claims

1. A grounding fault detection device for a DC system, characterized in that, For connection to a grounded busbar in a DC system, the device includes: The system includes a main control unit, a current detection unit, a voltage detection unit, and an excitation signal generation unit. The current detection unit, the voltage detection unit, and the excitation signal generation unit are connected to the main control unit; The current detection unit, the voltage detection unit, and the excitation signal generation unit are connected to the bus; wherein the excitation signal generation unit includes at least two stages of signal amplification circuit.

2. The DC system grounding fault detection device according to claim 1, characterized in that, The excitation signal generating unit includes a first signal amplification circuit and a second signal amplification circuit; the first signal amplification circuit is connected to the main control unit; the first signal amplification circuit and the bus are connected to the second signal amplification circuit.

3. The DC system grounding fault detection device according to claim 2, characterized in that, The first signal amplification circuit includes a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a first capacitor, a second capacitor, a third capacitor, a fourth capacitor, a fifth capacitor, a sixth capacitor, a first chip, and a first inductor; One end of the first resistor is connected to the main control unit; the other end of the first resistor is connected to one end of the second resistor; the other end of the second resistor and one end of the third capacitor are connected to the third pin of the first chip; one end of the third resistor is connected to the first power supply; one end of the fourth resistor and one end of the fifth resistor are connected to the other end of the third resistor; one end of the fourth resistor and one end of the second capacitor are connected to the second pin of the first chip; one end of the first capacitor and one end of the first inductor are connected to the first pin of the first chip; one end of the fourth capacitor is connected to the eighth pin of the first chip; one end of the fifth capacitor is connected to the seventh pin of the first chip. One end of the sixth capacitor is connected to the sixth pin of the first chip; The other end of the first capacitor, the other end of the second capacitor, the other end of the third capacitor, and the other end of the fifth resistor are connected to the first ground wire; The other end of the fifth capacitor, the other end of the sixth capacitor, and the fifth pin of the first chip are connected to the second ground line; The other end of the first inductor and the eighth pin of the first chip are connected to the second power supply; the other end of the fourth capacitor is connected to the third power supply. The sixth pin of the first chip is connected to the second signal amplifier circuit as the first output terminal of the first signal amplifier circuit, and the seventh pin of the first chip is connected to the second signal amplifier circuit as the second output terminal of the first signal amplifier circuit.

4. The DC system grounding fault detection device according to claim 2, characterized in that, The second signal amplification circuit includes a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor, a tenth resistor, an eleventh resistor, a twelfth resistor, a seventh capacitor, a first diode, a second diode, a third diode, a fourth diode, a first transistor, a second transistor, and a second chip; One end of the seventh resistor is connected to the second output terminal of the first signal amplifier circuit, and one end of the eighth resistor is connected to the first output terminal of the first signal amplifier circuit; one end of the sixth resistor and the other end of the seventh resistor are connected to the positive input terminal of the second chip; the other end of the sixth resistor is connected to the third power supply; one end of the ninth resistor, one end of the seventh capacitor, and the other end of the eighth resistor are connected to the negative input terminal of the second chip; one end of the tenth resistor is connected to the output terminal of the second chip; the tenth resistor, the cathode of the first diode, and the cathode of the second diode are connected; the cathode of the first diode and one end of the eleventh resistor are connected to the base of the first transistor; the emitter of the first transistor is connected to the emitter of the second transistor; one end of the twelfth resistor and the anode of the second diode are connected to the base of the second transistor; the anode of the third diode is connected to the cathode of the fourth diode. The other end of the eleventh resistor, the collector of the first transistor, the cathode of the third diode, and the first power supply terminal of the second chip are connected to the fourth power supply; the other end of the twelfth resistor, the collector of the second transistor, the anode of the fourth diode, and the second power supply terminal of the second chip are connected to the fifth power supply; the other end of the ninth resistor and the other end of the seventh capacitor are connected to the emitter of the first transistor; the emitter of the first transistor is connected to the bus as the output terminal of the second signal amplification circuit.

5. The DC system grounding fault detection device according to claim 2, characterized in that, The current detection unit includes a third amplifier circuit and a fourth amplifier circuit; the third amplifier circuit is connected to the bus; the third amplifier circuit is connected to the main control unit and the fourth amplifier circuit.

6. The DC system grounding fault detection device according to claim 5, characterized in that, The third amplifier circuit includes a thirteenth resistor, a fourteenth resistor, a fifteenth resistor, a sixteenth resistor, an eighth capacitor, a ninth capacitor, and a third chip; One end of the thirteenth resistor, one end of the eighth capacitor, and the busbar are connected to the negative input terminal of the third chip; one end of the thirteenth resistor, one end of the eighth capacitor, and one end of the sixteenth resistor are connected to the output terminal of the third chip; the other end of the sixteenth resistor serves as the output terminal of the third amplifier circuit. One end of the fourteenth resistor and one end of the fifteenth resistor are connected to the positive input terminal of the third chip; One end of the ninth capacitor and the first power supply terminal of the third chip are connected to the sixth power supply. The other end of the fourteenth resistor is connected to the first power supply; the other end of the fifteenth resistor, the other end of the ninth capacitor, and the second power supply terminal of the third chip are all grounded.

7. The DC system grounding fault detection device according to claim 5, characterized in that, The fourth amplifier circuit includes a seventeenth resistor, an eighteenth resistor, a nineteenth resistor, a twentieth resistor, a tenth capacitor, an eleventh capacitor, a twelfth capacitor, and a fourth chip; One end of the seventeenth resistor, one end of the tenth capacitor, and the output terminal of the third amplifier circuit are connected to the negative input terminal of the fourth chip; one end of the seventeenth resistor, one end of the tenth capacitor, and one end of the twentieth resistor are connected to the output terminal of the fourth chip; the other end of the twentieth resistor is connected to one end of the twelfth capacitor; the other end of the twentieth resistor serves as the output terminal of the fourth amplifier circuit. One end of the eighteenth resistor, one end of the nineteenth resistor, and one end of the eleventh capacitor are connected to the positive input terminal of the fourth chip; The other end of the eighteenth resistor is connected to the main control unit; the other end of the nineteenth resistor, the other end of the eleventh capacitor, the other end of the twelfth capacitor, and the second power supply terminal of the fourth chip are all grounded.

8. The DC system grounding fault detection device according to claim 1, characterized in that, The main control unit includes one or more STM32 series microcontrollers.

9. The DC system grounding fault detection device according to claim 1, characterized in that, The voltage detection unit includes a voltage acquisition circuit and a voltage amplification circuit; the voltage acquisition circuit and the main control unit are connected to the voltage amplification circuit.

10. A DC system grounding fault location system, characterized in that, It includes one or more of the DC system grounding fault detection devices as described in any one of claims 1-9.

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