Grounding current sampling device

Abstract

The utility model discloses a grounding current sampling device, which relates to the technical field of electronic circuits and comprises a signal processing module, a first voltage regulation module, a first comparison module, a second voltage regulation module and a second comparison module. The signal processing module is used for summing the three-phase current signals; the first voltage regulation module is used for generating a total signal source for current comparison; the second voltage regulation module is used for generating an upper limit voltage signal and a lower limit voltage signal for current comparison; the first comparison module is used for carrying out high-level comparison on the current signals; and the second comparison module is used for carrying out low-level comparison on the current signals. According to the utility model, rapid sampling and judgment of the grounding current are realized by adopting a hardware sampling and comparison method.

Description

Technical Field

[0001] The utility model relates to the field of electronic circuits, and particularly to a grounding current sampling device. Background Art

[0002] This section aims to provide background or context for the embodiments of the utility model described in the claims. The description herein is not admitted to be prior art merely by virtue of its inclusion in this section.

[0003] During the existing grounding three-phase current sampling process, a resistor voltage division method is adopted to implement current signal sampling, a voltage follower is used to achieve the tracking between the input voltage and the output current, reduce the load effect of the subsequent circuit, and utilize the simple load resistance characteristics to implement the current output function. After the software samples 3 current signals, summation calculation and comparison are performed. However, since the grounding current is a pulsed current, the existing method cannot capture the current after sampling the current and performing software summation and judgment, and cannot correctly complete the judgment and processing. Summary of the Utility Model

[0004] In an embodiment of the utility model, a grounding current sampling device is proposed, which uses a hardware sampling and comparison method to achieve fast sampling and judgment of the grounding current, ensuring the stability and low variation of the grounding current sampling and judgment. The grounding current sampling device includes: a signal processing module 1, a first voltage regulation module 2, a first comparison module 3, a second voltage regulation module 4, and a second comparison module 5;

[0005] Among them, the signal processing module 1 includes three input terminals: the first input terminal receives a first current signal, the second input terminal receives a second current signal, and the third input terminal receives a third current signal; the output terminal of the signal processing module 1 is respectively connected to the first input terminal of the first comparison module 3, the second input terminal of the second comparison module 5, and the first output terminal of the first voltage regulation module 2; the signal processing module 1 is used to sum the first current signal, the second current signal, and the third current signal;

[0006] The input terminal of the first voltage regulation module 2 is connected to a first voltage source, the first output terminal of the first voltage regulation module 2 is connected to the first input terminal of the first comparison module 3, the second input terminal of the second comparison module 5, and the output terminal of the signal processing module 1, and the second output terminal of the first voltage regulation module 2 is connected to the output terminals of the first comparison module 3 and the second comparison module 5; the first voltage regulation module 2 is used to generate a total signal source for current comparison;

[0007] The input terminal of the second voltage regulation module 4 is connected to the second voltage source. The first output terminal of the second voltage regulation module 4 is connected to the second input terminal of the first comparison module 3. The second output terminal of the second voltage regulation module 4 is connected to the first input terminal of the second comparison module 5. The third output terminal of the second voltage regulation module 4 is grounded. The second voltage regulation module 4 is used to generate an upper limit voltage signal and a lower limit voltage signal for current comparison.

[0008] The output terminal of the first comparison module 3 is connected to the output terminal of the second comparison module 5. The first comparison module 3 is used to perform a high-level comparison of the current signal. The second comparison module 5 is used to perform a low-level comparison of the current signal.

[0009] Further, the signal processing module 1 includes a first resistor, a second resistor, and a third resistor.

[0010] Wherein, the first end of the first resistor is the first input terminal of the signal processing module 1. The first end of the first resistor receives a first current signal. The first end of the second resistor is the second input terminal of the signal processing module 1. The first end of the second resistor receives a second current signal. The first end of the third resistor is the third input terminal of the signal processing module 1. The first end of the third resistor receives a third current signal. After the second ends of the first resistor, the second resistor, and the third resistor are connected, it is the output terminal of the signal processing module 1.

[0011] Further, the resistance value of the first resistor is 10 kΩ, the resistance value of the second resistor is 10 kΩ, and the resistance value of the third resistor is 10 kΩ.

[0012] Further, the first voltage regulation module 2 includes a fourth resistor and an eleventh resistor.

[0013] Wherein, the first end of the fourth resistor is the input terminal of the first voltage regulation module 2. The first end of the fourth resistor is connected to the first voltage source and the first end of the eleventh resistor. The second end of the fourth resistor is the first output terminal of the first voltage regulation module 2. The second end of the fourth resistor is connected to the output terminal of the signal processing module 1, the first input terminal of the first comparison module 3, and the second input terminal of the second comparison module 5. The second end of the eleventh resistor is the second output terminal of the first voltage regulation module 2. The second end of the eleventh resistor is connected to the output terminal of the first comparison module 3 and the output terminal of the second comparison module 5.

[0014] Further, the resistance value of the fourth resistor is 10 kΩ, and the resistance value of the eleventh resistor is 2 kΩ.

[0015] Further, the first comparison module 3 includes a sixth resistor and a first operational amplifier.

[0016] Among them, the first end of the sixth resistor is the first input end of the first comparison module 3. The first end of the sixth resistor is connected to the first output end of the first voltage regulation module 2 and the output end of the signal processing module 1. The second end of the sixth resistor is connected to the negative input end of the first operational amplifier; the positive input end of the first operational amplifier is the second input end of the first comparison module 3, and the positive input end of the first operational amplifier is connected to the first output end of the second voltage regulation module 4; the output end of the first operational amplifier is the output end of the first comparison module 3; the output end of the first operational amplifier is connected to the second output end of the first voltage regulation module 2 and the output end of the second comparison module 5.

[0017] Further, the resistance value of the sixth resistor is 1 kΩ.

[0018] Further, the second voltage regulation module 4 includes a fifth resistor, a seventh resistor, a ninth resistor, a tenth resistor, a twelfth resistor, a first capacitor, and a second capacitor;

[0019] Among them, the first end of the fifth resistor is the input end of the second voltage regulation module 4. The first end of the fifth resistor is connected to the second voltage source, and the second end of the fifth resistor is connected to the first end of the twelfth resistor; the second end of the twelfth resistor is the first output end of the second voltage regulation module 4, and the second end of the twelfth resistor is connected to the first end of the seventh resistor and the second input end of the first comparison module 3; the first end of the second capacitor is connected to the second end of the twelfth resistor, and the second end of the second capacitor is grounded; the second end of the seventh resistor is the second output end of the second voltage regulation module 4, and the second end of the seventh resistor is connected to the first end of the ninth resistor and the first input end of the second comparison module 5. The second end of the ninth resistor is connected to the first end of the tenth resistor; the first end of the tenth resistor is connected to the first end of the first capacitor, and the second end of the tenth resistor and the second end of the first capacitor are grounded.

[0020] Further, the resistance value of the fifth resistor is 10 kΩ, the resistance value of the seventh resistor is 1 kΩ, the resistance value of the ninth resistor is 2 kΩ, the resistance value of the tenth resistor is 2 kΩ, the resistance value of the twelfth resistor is 3 kΩ, the capacitance value of the first capacitor is 0.1 uF, and the capacitance value of the second capacitor is 0.1 uF.

[0021] Further, the second comparison module 5 includes an eighth resistor and a second operational amplifier;

[0022] Among them, the first end of the eighth resistor is the second input end of the second comparison module 5. The first end of the eighth resistor is connected to the output end of the signal processing module 1 and the first output end of the first voltage regulation module 2. The second end of the eighth resistor is connected to the positive input end of the first operational amplifier. The negative input end of the second operational amplifier is the first input end of the second comparison module 5. The negative input end of the second operational amplifier is connected to the second output end of the second voltage regulation module 4. The output end of the second operational amplifier is the output end of the second comparison module 5. The output end of the second operational amplifier is connected to the second output end of the first voltage regulation module 2 and the output end of the first comparison module 3.

[0023] Furthermore, the resistance value of the eighth resistor is 1 kΩ.

[0024] In the embodiment of the present utility model, the grounding current sampling device includes a signal processing module, a first voltage regulation module, a first comparison module, a second voltage regulation module, and a second comparison module. Among them, the signal processing module includes three input ends: the first input end receives a first current signal, the second input end receives a second current signal, and the third input end receives a third current signal. The output end of the signal processing module is respectively connected to the first input end of the first comparison module, the second input end of the second comparison module, and the first output end of the first voltage regulation module. The signal processing module is used to sum the first current signal, the second current signal, and the third current signal. The input end of the first voltage regulation module is connected to a first voltage source. The first output end of the first voltage regulation module is connected to the first input end of the first comparison module, the second input end of the second comparison module, and the output end of the signal processing module. The second output end of the first voltage regulation module is connected to the output end of the first comparison module and the output end of the second comparison module. The first voltage regulation module is used to generate a total signal source for current comparison. The input end of the second voltage regulation module is connected to a second voltage source. The first output end of the second voltage regulation module is connected to the second input end of the first comparison module. The second output end of the second voltage regulation module is connected to the first input end of the second comparison module. The third output end of the second voltage regulation module is grounded. The second voltage regulation module is used to generate an upper limit voltage signal and a lower limit voltage signal for current comparison. The output end of the first comparison module is connected to the output end of the second comparison module. The first comparison module is used to perform a high-level comparison of the current signal. The second comparison module is used to perform a low-level comparison of the current signal. The embodiment of the present utility model realizes the fast sampling and judgment of the grounding current by using a hardware sampling and comparison method, and further can solve the technical problem that since the grounding current is a pulsed current, in the prior art, after the current is collected, software summation and judgment are performed, and the current cannot be captured, and the judgment and processing cannot be correctly completed. Description of the Drawings

[0025] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings. In the drawings:

[0026] Figure 1 It is a schematic diagram of a grounding current sampling device provided in an embodiment of the present invention;

[0027] Figure 2 It is a circuit diagram of a grounding current sampling device provided in an embodiment of the present invention. Detailed implementation manners

[0028] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer and more understandable, the following further details the embodiments of the present invention with reference to the drawings. Herein, the illustrative embodiments of the present invention and their descriptions are used to explain the present invention, but not to limit the present invention.

[0029] The term "and / or" in this article only describes an associated relationship, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the term "at least one" in this article means any one or any combination of at least two of a plurality. For example, including at least one of A, B, and C can represent including any one or more elements selected from the set composed of A, B, and C.

[0030] In the description of this specification, the terms "include", "comprise", "have", "contain", etc. are all open-ended terms, that is, they are meant to include but not be limited to. The description with reference to terms such as "an embodiment", "a specific embodiment", "some embodiments", "for example", etc. means that the specific features, structures or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of this application. In this specification, the schematic descriptions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. The order of the steps involved in each embodiment is used to schematically illustrate the implementation of this application, and the order of the steps is not limited and can be adjusted appropriately as needed.

[0031] Figure 1 It is a schematic diagram of a grounding current sampling device provided in an embodiment of the present invention, as Figure 1 shown, the grounding current sampling device includes:

[0032] A signal processing module 1, a first voltage regulation module 2, a first comparison module 3, a second voltage regulation module 4, and a second comparison module 5;

[0033] Among them, the signal processing module 1 includes three input terminals: the first input terminal receives a first current signal, the second input terminal receives a second current signal, and the third input terminal receives a third current signal; the output terminal of the signal processing module 1 is respectively connected to the first input terminal of the first comparison module 3, the second input terminal of the second comparison module 5, and the first output terminal of the first voltage regulation module 2; the signal processing module 1 is used to sum the first current signal, the second current signal, and the third current signal;

[0034] The input terminal of the first voltage regulation module 2 is connected to a first voltage source, the first output terminal of the first voltage regulation module 2 is connected to the first input terminal of the first comparison module 3, the second input terminal of the second comparison module 5, and the output terminal of the signal processing module 1, and the second output terminal of the first voltage regulation module 2 is connected to the output terminal of the first comparison module 3 and the output terminal of the second comparison module 5; the first voltage regulation module 2 is used to generate a total signal source for current comparison;

[0035] The input terminal of the second voltage regulation module 4 is connected to a second voltage source, the first output terminal of the second voltage regulation module 4 is connected to the second input terminal of the first comparison module 3, the second output terminal of the second voltage regulation module 4 is connected to the first input terminal of the second comparison module 5, and the third output terminal of the second voltage regulation module 4 is grounded; the second voltage regulation module 4 is used to generate an upper limit voltage signal and a lower limit voltage signal for current comparison;

[0036] The output terminal of the first comparison module 3 is connected to the output terminal of the second comparison module 5; the first comparison module 3 is used to perform a high-level comparison of the current signal; the second comparison module 5 is used to perform a low-level comparison of the current signal.

[0037] Figure 2 This is a circuit diagram of a ground current sampling device provided in an embodiment of the present invention.

[0038] In one embodiment, referring to Figure 2 , the signal processing module 1 includes a first resistor R1, a second resistor R2, and a third resistor R3;

[0039] Among them, the first end of the first resistor R1 is the first input end of the signal processing module 1. The first end of the first resistor R1 receives the first current signal. The first end of the second resistor R2 is the second input end of the signal processing module 1. The first end of the second resistor R2 receives the second current signal. The first end of the third resistor R3 is the third input end of the signal processing module 1. The first end of the third resistor R3 receives the third current signal. After the second ends of the first resistor R1, the second resistor R2, and the third resistor R3 are connected, it is the output end of the signal processing module 1.

[0040] In one embodiment, the resistance value of the first resistor is 10 kΩ, the resistance value of the second resistor is 10 kΩ, and the resistance value of the third resistor is 10 kΩ.

[0041] Specifically, the first input end of the signal processing module 1 receives the first current signal Iu, the second input end receives the second current signal Iv, and the third input end receives the third current signal Iw. There is no mutual influence among the current signals Iu, Iv, and Iw, nor is there a load effect. The current signal Iu passes through the first resistor R1, Iv passes through the second resistor R2, and Iw passes through the third resistor R3 and then is summed and enters the first comparison module and the second comparison module.

[0042] In one embodiment, refer to Figure 2 , the first voltage regulation module 2 includes a fourth resistor R4 and an eleventh resistor R11;

[0043] Among them, the first end of the fourth resistor is the input end of the first voltage regulation module 2. The first end of the fourth resistor is connected to the first voltage source and the first end of the eleventh resistor. The second end of the fourth resistor is the first output end of the first voltage regulation module 2. The second end of the fourth resistor is connected to the output end of the signal processing module 1, the first input end of the first comparison module 3, and the second input end of the second comparison module 5. The second end of the eleventh resistor is the second output end of the first voltage regulation module 2. The second end of the eleventh resistor is connected to the output end of the first comparison module 3 and the output end of the second comparison module 5.

[0044] In one embodiment, the resistance value of the fourth resistor is 10 kΩ, and the resistance value of the eleventh resistor is 2 kΩ.

[0045] Specifically, the voltage of the first voltage source is 3V. After being divided by the fourth resistor R4, the total signal source Vo for current comparison is generated.

[0046] In the embodiment of the present invention, a filter circuit is further included. The filter circuit includes a third capacitor C3. The first end of the third capacitor C3 is connected to the first output end of the first voltage regulation module. The second end of the third capacitor C3 is grounded. The third capacitor C3 is used to filter the voltage signal Vo output from the first output end of the first voltage regulation module. The capacitance value of C3 is 0.1 Uf.

[0047] In one embodiment, referring to Figure 2 , the second voltage regulation module 4 includes a fifth resistor R5, a seventh resistor R7, a ninth resistor R9, a tenth resistor R10, a twelfth resistor R12, a first capacitor C1, and a second capacitor C2;

[0048] Among them, the first end of the fifth resistor is the input end of the second voltage regulation module 4. The first end of the fifth resistor is connected to the second voltage source, and the second end of the fifth resistor is connected to the first end of the twelfth resistor; the second end of the twelfth resistor is the first output end of the second voltage regulation module 4. The second end of the twelfth resistor is connected to the first end of the seventh resistor and the second input end of the first comparison module 3; the first end of the second capacitor is connected to the second end of the twelfth resistor, and the second end of the second capacitor is grounded; the second end of the seventh resistor is the second output end of the second voltage regulation module 4. The second end of the seventh resistor is connected to the first end of the ninth resistor and the first input end of the second comparison module 5, and the second end of the ninth resistor is connected to the first end of the tenth resistor; the first end of the tenth resistor is connected to the first end of the first capacitor, and the second end of the tenth resistor and the second end of the first capacitor are grounded.

[0049] In one embodiment, the resistance value of the fifth resistor is 10 kΩ, the resistance value of the seventh resistor is 1 kΩ, the resistance value of the ninth resistor is 2 kΩ, the resistance value of the tenth resistor is 2 kΩ, the resistance value of the twelfth resistor is 3 kΩ, the capacitance value of the first capacitor is 0.1 uF, and the capacitance value of the second capacitor is 0.1 uF.

[0050] Specifically, the second voltage regulation module uses the power supply voltage of 3V as the reference source. First, after voltage division by R5 and R12, the upper limit voltage signal Vh for current comparison is generated. After the upper limit voltage signal Vh for current comparison is filtered by the capacitor C2, a stable comparison point is formed as the input signal of the first operational amplifier; then, after voltage division by R7, R9, and R10, the lower limit voltage signal Vl for current comparison is generated. After the lower limit voltage signal Vl for current comparison is filtered by the capacitor C1, it is used as the input signal of the second operational amplifier.

[0051] In one embodiment, referring to Figure 2 , the first comparison module 3 includes a sixth resistor R6 and a first operational amplifier A;

[0052] Among them, the first end of the sixth resistor is the first input end of the first comparison module 3. The first end of the sixth resistor is connected to the first output end of the first voltage regulation module 2 and the output end of the signal processing module 1. The second end of the sixth resistor is connected to the negative input end of the first operational amplifier. The positive input end of the first operational amplifier is the second input end of the first comparison module 3, and the positive input end of the first operational amplifier is connected to the first output end of the second voltage regulation module 4. The output end of the first operational amplifier is the output end of the first comparison module 3. The output end of the first operational amplifier is connected to the second output end of the first voltage regulation module 2 and the output end of the second comparison module 5.

[0053] In one embodiment, the resistance value of the sixth resistor is 1 kΩ.

[0054] In one embodiment, referring to Figure 2 , the second comparison module 5 includes an eighth resistor R8 and a second operational amplifier B;

[0055] Among them, the first end of the eighth resistor is the second input end of the second comparison module 5. The first end of the eighth resistor is connected to the output end of the signal processing module 1 and the first output end of the first voltage regulation module 2. The second end of the eighth resistor is connected to the positive input end of the first operational amplifier. The negative input end of the second operational amplifier is the first input end of the second comparison module 5. The negative input end of the second operational amplifier is connected to the second output end of the second voltage regulation module 4. The output end of the second operational amplifier is the output end of the second comparison module 5. The output end of the second operational amplifier is connected to the second output end of the first voltage regulation module 2 and the output end of the first comparison module 3.

[0056] In one embodiment, the resistance value of the eighth resistor is 1 kΩ.

[0057] Specifically, the first comparison module 3 is used for high-level comparison of current signals; the second comparison module 5 is used for low-level comparison of current signals. The current signals Iu, Iv, and Iw are summed after passing through the signal processing module, and then connected to the negative input end of the first operational amplifier A after passing through the R6 current-limiting resistor, serving as the input signal for overcurrent upper limit judgment. At the same time, after passing through the current-limiting resistor R8, it is connected to the positive input end of the second operational amplifier B, serving as the input signal for overcurrent lower limit judgment. Then, after the judgment of the first operational amplifier A and the second operational amplifier B, the judgment result Do is output.

[0058] In this way, through Figure 2 the 2 operational amplifiers, 3 capacitors and 12 resistors shown, the sampling and judgment of three-phase current signals under the grounded condition can be realized.

[0059] In addition, in the embodiments of the present utility model, by means of the form of integrated resistors and by mounting two operational amplifiers on the same circuit board, the characteristics of the operational amplifiers are ensured to be exactly the same. At the same time, the drift of the resistance value caused by temperature is further reduced, ensuring the stability and low variation of the grounding current sampling and judgment of this solution.

[0060] To sum up, in the embodiments of the present utility model, the grounding current sampling device includes a signal processing module, a first voltage regulation module, a first comparison module, a second voltage regulation module, and a second comparison module; wherein, the signal processing module includes three input terminals: the first input terminal receives a first current signal, the second input terminal receives a second current signal, and the third input terminal receives a third current signal; the output terminal of the signal processing module is respectively connected to the first input terminal of the first comparison module, the second input terminal of the second comparison module, and the first output terminal of the first voltage regulation module; the signal processing module is used to sum the first current signal, the second current signal, and the third current signal; the input terminal of the first voltage regulation module is connected to a first voltage source, the first output terminal of the first voltage regulation module is connected to the first input terminal of the first comparison module, the second input terminal of the second comparison module, and the output terminal of the signal processing module, and the second output terminal of the first voltage regulation module is connected to the output terminal of the first comparison module and the output terminal of the second comparison module; the first voltage regulation module is used to generate a total signal source for current comparison; the input terminal of the second voltage regulation module is connected to a second voltage source, the first output terminal of the second voltage regulation module is connected to the second input terminal of the first comparison module, the second output terminal of the second voltage regulation module is connected to the first input terminal of the second comparison module, and the third output terminal of the second voltage regulation module is grounded; the second voltage regulation module is used to generate an upper limit voltage signal and a lower limit voltage signal for current comparison; the output terminal of the first comparison module is connected to the output terminal of the second comparison module; the first comparison module is used to perform a high-level comparison of the current signal; the second comparison module is used to perform a low-level comparison of the current signal. The embodiments of the present utility model adopt a hardware sampling and comparison method to achieve rapid sampling and judgment of the grounding current, thereby solving the technical problem that since the grounding current is a pulsed current, the prior art cannot capture the current and cannot correctly complete the judgment and processing after collecting the current and performing software summation and judgment.

[0061] In the specific embodiments described above, the purpose, technical solution, and beneficial effects of the present utility model have been further described in detail. It should be understood that the above description is only for the specific embodiments of the present utility model and is not used to limit the protection scope of the present utility model. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present utility model shall be included in the protection scope of the present utility model.

Claims

1. A grounding current sampling device, characterized in that Including: A signal processing module (1), a first voltage regulation module (2), a first comparison module (3), a second voltage regulation module (4), and a second comparison module (5); Among them, the signal processing module (1) includes three input terminals: the first input terminal receives a first current signal, the second input terminal receives a second current signal, and the third input terminal receives a third current signal; the output terminal of the signal processing module (1) is respectively connected to the first input terminal of the first comparison module (3), the second input terminal of the second comparison module (5), and the first output terminal of the first voltage regulation module (2); the signal processing module (1) is used to sum the first current signal, the second current signal, and the third current signal; The input terminal of the first voltage regulation module (2) is connected to a first voltage source, the first output terminal of the first voltage regulation module (2) is connected to the first input terminal of the first comparison module (3), the second input terminal of the second comparison module (5), and the output terminal of the signal processing module (1), and the second output terminal of the first voltage regulation module (2) is connected to the output terminal of the first comparison module (3) and the output terminal of the second comparison module (5); the first voltage regulation module (2) is used to generate a total signal source for current comparison; The input terminal of the second voltage regulation module (4) is connected to a second voltage source, the first output terminal of the second voltage regulation module (4) is connected to the second input terminal of the first comparison module (3), the second output terminal of the second voltage regulation module (4) is connected to the first input terminal of the second comparison module (5), and the third output terminal of the second voltage regulation module (4) is grounded; the second voltage regulation module (4) is used to generate an upper limit voltage signal and a lower limit voltage signal for current comparison; The output terminal of the first comparison module (3) is connected to the output terminal of the second comparison module (5); the first comparison module (3) is used to perform high-level comparison of current signals; the second comparison module (5) is used to perform low-level comparison of current signals.

2. The grounding current sampling device according to claim 1, characterized in that The signal processing module (1) includes a first resistor, a second resistor, and a third resistor; Among them, the first end of the first resistor is the first input terminal of the signal processing module (1), the first end of the second resistor is the second input terminal of the signal processing module (1), and the first end of the third resistor is the third input terminal of the signal processing module (1); after the second ends of the first resistor, the second resistor, and the third resistor are connected, it is the output terminal of the signal processing module (1).

3. The grounding current sampling device according to claim 2, characterized in that, The resistance value of the first resistor is 10 kΩ, the resistance value of the second resistor is 10 kΩ, and the resistance value of the third resistor is 10 kΩ.

4. The grounding current sampling device according to claim 1, characterized in that, The first voltage regulation module (2) includes a fourth resistor and an eleventh resistor; Among them, the first end of the fourth resistor is the input end of the first voltage regulation module (2). The first end of the fourth resistor is connected to the first voltage source and the first end of the eleventh resistor. The second end of the fourth resistor is the first output end of the first voltage regulation module (2). The second end of the fourth resistor is connected to the output end of the signal processing module (1), the first input end of the first comparison module (3), and the second input end of the second comparison module (5). The second end of the eleventh resistor is the second output end of the first voltage regulation module (2). The second end of the eleventh resistor is connected to the output end of the first comparison module (3) and the output end of the second comparison module (5).

5. The grounding current sampling device according to claim 4, wherein The resistance value of the fourth resistor is 10 kΩ, and the resistance value of the eleventh resistor is 2 kΩ.

6. The grounding current sampling device according to claim 1, characterized in that, The first comparison module (3) includes a sixth resistor and a first operational amplifier; Among them, the first end of the sixth resistor is the first input end of the first comparison module (3). The first end of the sixth resistor is connected to the first output end of the first voltage regulation module (2) and the output end of the signal processing module (1). The second end of the sixth resistor is connected to the negative input end of the first operational amplifier. The positive input end of the first operational amplifier is the second input end of the first comparison module (3). The positive input end of the first operational amplifier is connected to the first output end of the second voltage regulation module (4). The output end of the first operational amplifier is the output end of the first comparison module (3). The output end of the first operational amplifier is connected to the second output end of the first voltage regulation module (2) and the output end of the second comparison module (5).

7. The grounding current sampling device according to claim 6, characterized in that, The resistance value of the sixth resistor is 1 kΩ.

8. The grounding current sampling device according to claim 1, wherein The second voltage regulation module (4) includes a fifth resistor, a seventh resistor, a ninth resistor, a tenth resistor, a twelfth resistor, a first capacitor, and a second capacitor; Among them, the first end of the fifth resistor is the input end of the second voltage regulation module (4). The first end of the fifth resistor is connected to the second voltage source. The second end of the fifth resistor is connected to the first end of the twelfth resistor. The second end of the twelfth resistor is the first output end of the second voltage regulation module (4). The second end of the twelfth resistor is connected to the first end of the seventh resistor and the second input end of the first comparison module (3). The first end of the second capacitor is connected to the second end of the twelfth resistor. The second end of the second capacitor is grounded. The second end of the seventh resistor is the second output end of the second voltage regulation module (4). The second end of the seventh resistor is connected to the first end of the ninth resistor and the first input end of the second comparison module (5). The second end of the ninth resistor is connected to the first end of the tenth resistor. The first end of the tenth resistor is connected to the first end of the first capacitor. The second end of the tenth resistor and the second end of the first capacitor are grounded.

9. The grounding current sampling device according to claim 8, wherein The resistance value of the fifth resistor is 10 kΩ, the resistance value of the seventh resistor is 1 kΩ, the resistance value of the ninth resistor is 2 kΩ, the resistance value of the tenth resistor is 2 kΩ, the resistance value of the twelfth resistor is 3 kΩ, the capacitance value of the first capacitor is 0.1 uF, and the capacitance value of the second capacitor is 0.1 uF.

10. The grounding current sampling device according to claim 1, wherein The second comparison module (5) includes an eighth resistor and a second operational amplifier; Among them, the first end of the eighth resistor is the second input end of the second comparison module (5). The first end of the eighth resistor is connected to the output end of the signal processing module (1) and the first output end of the first voltage regulation module (2). The second end of the eighth resistor is connected to the positive input end of the first operational amplifier. The negative input end of the second operational amplifier is the first input end of the second comparison module (5). The negative input end of the second operational amplifier is connected to the second output end of the second voltage regulation module (4). The output end of the second operational amplifier is the output end of the second comparison module (5). The output end of the second operational amplifier is connected to the second output end of the first voltage regulation module (2) and the output end of the first comparison module (3).

11. The grounding current sampling device according to claim 10, characterized in that, The resistance value of the eighth resistor is 1 kΩ.

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