AC grounding detection circuit, system and equipment

Abstract

The utility model relates to an AC grounding detection circuit, system and device, and the circuit comprises a current detection module, a comparator module and a main control module, carries out the voltage sampling through a voltage-to-ground detection module, obtains a first voltage signal of a zero line to a ground line, carries out the power grid voltage sampling through an AC voltage detection module, obtains a second voltage signal, and outputs the second voltage signal to the main control module. The detection processing module can carry out voltage comparison based on the second voltage signal and the first voltage signal, so as to determine an AC grounding detection result based on a voltage comparison result in combination with a preset grounding abnormal voltage difference range. Therefore, the problem that in the prior art, when the detection cost is reduced, whether grounding is good or not cannot be judged due to reverse connection of the live line and the zero line, and consequently the accuracy of alternating current grounding detection is low is solved, and the accuracy of alternating current grounding detection is further improved while the detection cost is saved.

Description

Technical Field

[0001] This application relates to the field of grounding detection technology, and in particular to an AC grounding detection circuit, system, and device. Background Technology

[0002] Currently, many AC devices are connected to the power grid. During use, the grounding status of these devices is crucial for their safety. If an AC device is not grounded or poorly grounded (manifested as excessive grounding resistance) when connected to the grid, a leakage fault in the device can cause electric shock to anyone who touches it, resulting in injury. Therefore, to ensure a good grounding status for AC devices, they must have a grounding detection function. When connected to the power grid, the grounding resistance of the earth should be measured using AC current to determine whether the AC device is properly grounded.

[0003] Specifically, the principle of existing AC grounding detection schemes is usually to measure the voltage and current values ​​of the grounding circuit and use Ohm's law to calculate the grounding resistance, and then determine whether the grounding is good based on the calculation result. This method requires a high-precision Hall current sensor to be connected in series in the grounding circuit. However, Hall current sensors are relatively expensive, and the cost of the grounding detection circuit is high, which greatly increases the cost of AC grounding detection.

[0004] Existing technologies for AC grounding detection primarily rely on obtaining the voltage value of the neutral (N) wire to ground within the equipment to determine whether the grounding is good. However, when the live (L) wire and the N wire are reversed, this detection method cannot determine whether the grounding is good, affecting the accuracy of AC grounding detection. Utility Model Content

[0005] In view of this, this application provides an AC grounding detection circuit, system, and device, which can solve the problem of low accuracy of AC grounding detection caused by the inability to determine whether the grounding is good when the live wire and neutral wire are reversed, even when the detection cost is reduced.

[0006] In a first aspect, embodiments of this application provide an AC grounding detection circuit, including: a ground voltage detection module, an AC voltage detection module, a bias power supply module, and a detection processing module;

[0007] The in-phase input detection terminal of the ground voltage detection module is electrically connected to the ground wire of the energy storage device; the inverting input detection terminal of the ground voltage detection module, the inverting input detection terminal of the AC voltage detection module, and the neutral wire are electrically connected; the output terminal of the ground voltage detection module is electrically connected to the first input terminal of the detection processing module; the in-phase input detection terminal of the AC voltage detection module is electrically connected to the live wire; the output terminal of the AC voltage detection module is electrically connected to the second input terminal of the detection processing module; and the bias power supply terminal of the AC voltage detection module, the bias power supply terminal of the ground voltage detection module, and the output terminal of the bias power supply module are electrically connected.

[0008] The ground voltage detection module is used to perform voltage sampling based on the bias voltage signal provided by the bias power supply module to obtain the first voltage signal between the neutral wire and the ground wire.

[0009] The AC voltage detection module is used to sample the grid voltage based on the bias voltage signal to obtain a second voltage signal;

[0010] The detection and processing module is used to determine the voltage difference based on the second voltage signal and the first voltage signal; if the voltage difference is within a preset grounding abnormal voltage difference range, it is determined to be a grounding abnormality; or, if the voltage difference is not within the preset grounding abnormal voltage difference range, it is determined to be a normal grounding and the connection of the live wire and the neutral wire is normal when the voltage difference is less than the first voltage threshold, and it is determined to be a normal grounding and the connection of the live wire and the neutral wire is reversed when the voltage difference is greater than the second voltage threshold.

[0011] Optionally, the voltage to ground detection module includes a first resistor, a second resistor, a third resistor, a fourth resistor, a first capacitor, a second capacitor, a third capacitor, and a first amplifier;

[0012] The first end of the first resistor, the first end of the first capacitor, and the output end of the bias power supply module are electrically connected, and the second end of the first resistor, the second end of the first capacitor, and the non-inverting input end of the first amplifier are electrically connected.

[0013] The non-inverting input terminal of the first amplifier is electrically connected to the ground wire through the second resistor, and the inverting input terminal of the first amplifier is electrically connected to the neutral wire through the third resistor. Furthermore, the inverting input terminal of the first amplifier, the first end of the fourth resistor, and the first end of the second capacitor are electrically connected. The second end of the fourth resistor and the second end of the second capacitor are also electrically connected.

[0014] The output terminal of the first amplifier and the first input terminal of the detection and processing module are electrically connected.

[0015] One end of the third capacitor is electrically connected to the second resistor, and the other end of the third capacitor is electrically connected to the third resistor.

[0016] Optionally, the voltage to ground detection module further includes a fourth capacitor, the first terminal of which is electrically connected to the power supply terminal of the first amplifier and the power supply terminal of the AC ground detection circuit, and the second terminal of which is electrically connected to the reference ground of the AC ground detection circuit.

[0017] Optionally, the AC voltage detection module includes a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, a fifth capacitor, a sixth capacitor, a seventh capacitor, and a second amplifier;

[0018] The first end of the fifth resistor, the first end of the fifth capacitor, and the output end of the bias power supply module are electrically connected; the second end of the fifth resistor, the second end of the fifth capacitor, and the non-inverting input end of the second amplifier are electrically connected.

[0019] The non-inverting input terminal of the second amplifier is electrically connected to the live wire through the sixth resistor, and the inverting input terminal of the second amplifier is electrically connected to the neutral wire through the seventh resistor. The inverting input terminal of the second amplifier, the first end of the eighth resistor, and the first end of the seventh capacitor are electrically connected. The second end of the eighth resistor, the second end of the seventh capacitor, the output terminal of the second amplifier, and the second input terminal of the detection and processing module are electrically connected.

[0020] One end of the sixth capacitor is electrically connected to the sixth resistor, and the other end of the sixth capacitor is electrically connected to the seventh resistor.

[0021] Optionally, the detection processing module includes: a controller;

[0022] The first input terminal of the controller is electrically connected to the output terminal of the ground voltage detection module, and the second input terminal of the controller is connected to the output terminal of the AC voltage detection module.

[0023] The controller is specifically used to subtract the voltage value of the first voltage signal from the voltage value of the second voltage signal to obtain the voltage difference; if the voltage difference is less than the first voltage threshold, it is determined that the grounding is normal and the connection between the live wire and the neutral wire is normal; if the voltage difference is greater than the second voltage threshold, it is determined that the grounding is normal and the live wire and the neutral wire are reversed; if the voltage difference is not less than the first voltage threshold and not greater than the second voltage threshold, it is determined that the grounding is abnormal.

[0024] Optionally, the detection processing module includes: a voltage comparator unit and a detection result output unit;

[0025] The inverting input terminal of the voltage comparator unit is electrically connected to the output terminal of the voltage to ground detection module, the non-inverting input terminal of the voltage comparator unit is connected to the output terminal of the AC voltage detection module, and the output terminal of the voltage comparator unit is electrically connected to the input terminal of the detection result output unit.

[0026] The voltage comparator unit is used to subtract the voltage value of the first voltage signal from the voltage value of the second voltage signal, and output the voltage difference;

[0027] The detection result output unit is specifically configured to: output a first detection result when the voltage difference is less than the first voltage threshold, the first detection result indicating that the grounding is normal and the live wire and the neutral wire are connected normally; or output a second detection result when the voltage difference is greater than the second voltage threshold, the second detection result indicating that the grounding is normal and the live wire and the neutral wire are reversed; or output a third detection result when the voltage difference is not less than the first voltage threshold and not greater than the second voltage threshold, the third detection result indicating that the grounding is abnormal.

[0028] Optionally, the voltage comparator unit includes a first comparator, a ninth resistor, a tenth resistor, an eleventh resistor, a twelfth resistor, a thirteenth resistor, an eighth capacitor, a ninth capacitor, a tenth capacitor, an eleventh capacitor, and a twelfth capacitor.

[0029] Specifically, the first end of the ninth resistor, the first end of the eighth capacitor, and the output end of the bias power supply module are electrically connected; the second end of the ninth resistor, the second end of the eighth capacitor, the first end of the tenth capacitor, the second end of the tenth resistor, and the non-inverting input end of the first comparator are electrically connected; the first end of the tenth resistor is electrically connected to the output end of the AC voltage detection module; the inverting input end of the first comparator, the second end of the eleventh resistor, the first end of the twelfth resistor, the second end of the tenth capacitor, and the first end of the ninth capacitor are electrically connected; the first end of the eleventh resistor is electrically connected to the output end of the voltage to ground detection module; the second end of the twelfth resistor, the second end of the ninth capacitor, the output end of the first comparator, and the first end of the thirteenth resistor are electrically connected; and the second end of the thirteenth resistor, the first end of the eleventh capacitor, and the input end of the detection result output unit are electrically connected.

[0030] The first terminal of the twelfth capacitor, the power supply terminal of the first comparator, and the power supply terminal of the AC ground detection circuit are electrically connected, and the second terminal of the twelfth capacitor, the second terminal of the eleventh capacitor, and the reference ground of the AC ground detection circuit are electrically connected.

[0031] Optionally, the detection result output unit includes a second comparator, a third comparator, a fourth comparator, a fifth comparator, a first diode, a second diode, a third diode, a fourth diode, a first pull-up resistor, a second pull-up resistor, a third pull-up resistor, a fourth pull-up resistor, a fourteenth resistor, a fifteenth resistor, a sixteenth resistor, a seventeenth resistor, a thirteenth capacitor, a fourteenth capacitor, a fifteenth capacitor, and a first transistor;

[0032] The non-inverting input of the second comparator, the inverting input of the third comparator, the non-inverting input of the fourth comparator, the inverting input of the fifth comparator, and the output of the voltage comparator unit are electrically connected. The power supply terminal of the second comparator, the first terminal of the thirteenth capacitor, the first terminal of the first pull-up resistor, the first terminal of the second pull-up resistor, the power supply terminal of the fourth comparator, the first terminal of the fourteenth capacitor, the first terminal of the third pull-up resistor, the first terminal of the fourth pull-up resistor, the first terminal of the seventeenth resistor, and the power supply terminal of the AC grounding detection circuit are electrically connected. The inverting input of the second comparator is electrically connected to the first voltage terminal. The output of the second comparator, the second terminal of the first pull-up resistor, and the anode of the first diode are electrically connected. The cathodes of the first diode, the second diode, the third diode, the fourth diode, and the first terminal of the fifteenth resistor are electrically connected. The first voltage terminal is used to provide a first reference signal corresponding to the first voltage threshold.

[0033] The non-inverting input terminal of the third comparator is electrically connected to the second voltage terminal, and the output terminal of the third comparator, the second terminal of the second pull-up resistor, and the anode of the second diode are electrically connected. The second voltage terminal is used to provide a second reference signal corresponding to the first voltage threshold, and the voltage of the first reference signal is higher than the voltage of the second reference signal.

[0034] The inverting input terminal of the fourth comparator is electrically connected to the third voltage terminal, and the output terminal of the fourth comparator, the second terminal of the third pull-up resistor, and the anode of the third diode are electrically connected. The third voltage terminal is used to provide a third reference signal corresponding to the second voltage threshold.

[0035] The non-inverting input terminal of the fifth comparator is electrically connected to the fourth voltage terminal. The output terminal of the fifth comparator, the second terminal of the fourth pull-up resistor, and the anode of the fourth diode are electrically connected. The fourth voltage terminal is used to provide a fourth reference signal corresponding to the second voltage threshold. The voltage of the fourth reference signal is higher than the voltage of the second reference signal, and the voltage of the fourth reference signal is lower than the voltage of the third reference signal.

[0036] The second terminal of the fifteenth resistor, the first terminal of the sixteenth resistor, the first terminal of the fifteenth capacitor, and the control terminal of the first transistor are electrically connected. The first terminal of the first crystal, the second terminal of the seventeenth resistor, and the output terminal of the detection result output unit are electrically connected. The second terminal of the sixteenth resistor, the second terminal of the fifteenth capacitor, the second terminal of the first transistor, the ground terminal of the second comparator, the ground terminal of the fourth comparator, and the reference ground of the AC ground detection circuit are electrically connected.

[0037] Secondly, embodiments of this application provide an AC grounding detection system, comprising an AC grounding detection circuit as described in any of the first aspects and an electrical component electrically connected to the AC grounding detection circuit.

[0038] Thirdly, embodiments of this application provide an energy storage device, which includes an AC grounding detection circuit as described in the first aspect of this application and electrical components electrically connected to the AC grounding detection circuit.

[0039] The AC grounding detection circuit, system, and device provided in this application embodiment obtain a first voltage signal between the neutral wire and the ground wire by sampling the voltage of the ground voltage detection module based on the bias voltage signal provided by the bias power supply module, and obtain a second voltage signal by sampling the grid voltage based on the bias voltage signal provided by the AC voltage detection module. This allows the detection processing module to compare the second voltage signal with the first voltage signal, and determine the AC grounding detection result based on the voltage comparison result and a preset grounding abnormal voltage difference range. This eliminates the need for existing AC grounding detection schemes that require high-precision but costly Hall current sensors to be inserted into the grounding circuit, thus achieving an accurate judgment of whether the grounding is good. This saves detection costs and further improves the accuracy of AC grounding detection. Attached Figure Description

[0040] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the present invention and, together with the description, serve to explain the principles of the present invention.

[0041] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0042] One or more embodiments are illustrated by way of example with reference numerals in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Elements with the same reference numerals in the drawings are denoted as similar elements. Unless otherwise stated, the figures in the drawings are not to be limited by scale.

[0043] Figure 1 A structural block diagram of an AC grounding detection circuit provided in an embodiment of this application;

[0044] Figure 2 This is a schematic diagram illustrating how a voltage comparison is performed by a detection processing module to determine the grounding detection result, as an example of this application.

[0045] Figure 3 A schematic diagram of the circuit structure of a ground voltage detection module provided in an optional embodiment of this application;

[0046] Figure 4 A circuit structure diagram of an AC voltage detection module provided in an optional embodiment of this application;

[0047] Figure 5 This is a schematic diagram of the structure of a detection processing module using a controller, provided in an optional embodiment of this application.

[0048] Figure 6 This is a schematic diagram of the structure of an AC grounding detection circuit provided in an optional embodiment of this application;

[0049] Figure 7 This is a schematic diagram of the structure of a detection processing module provided in an optional embodiment of this application;

[0050] Figure 8 This is a schematic diagram of the structure of an AC grounding detection system provided in an embodiment of this application;

[0051] Figure 9 This is a structural block diagram of an energy storage device provided in an embodiment of this application. Detailed Implementation

[0052] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0053] The following disclosure provides numerous different embodiments or examples for implementing various structures of the present invention. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the scope of the invention. Furthermore, reference numerals and / or letters may be repeated in different examples. Such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed.

[0054] Figure 1 This is a structural block diagram of an AC grounding detection circuit provided in an embodiment of this application. Figure 1 As shown, the AC grounding detection circuit provided in this embodiment may specifically include: a ground voltage detection module 110, an AC voltage detection module 120, a bias power supply module 130, and a detection processing module 140; wherein, the non-inverting input detection terminal of the ground voltage detection module 110 is electrically connected to the ground wire Earth of the energy storage device, the inverting input detection terminal of the ground voltage detection module 110, the inverting input detection terminal of the AC voltage detection module 120, and the neutral wire Grid_N are electrically connected, the output terminal of the ground voltage detection module 110 is electrically connected to the first input terminal of the detection processing module 140, and the bias power supply terminal of the AC voltage detection module 120, the bias power supply terminal of the ground voltage detection module 110, and the output terminal of the bias power supply module 130 are electrically connected, so that the ground voltage detection module 110 can perform voltage sampling based on the bias voltage signal Voffset provided by the bias power supply module 130 to obtain the ground voltage detection signal Voffset of the neutral wire Grid_N. The first voltage signal Vearth of the ground wire Earth can be transmitted to the first input terminal of the detection and processing module 140. The in-phase input detection terminal of the AC voltage detection module 120 is electrically connected to the live wire Grid_L, so that the AC voltage detection module 120 can sample the grid voltage based on the bias voltage signal Voffset provided by the bias power supply module 130 to obtain the second voltage signal Vgrid. The output terminal of the AC voltage detection module 120 is electrically connected to the second input terminal of the detection and processing module 140, so that the second voltage signal Vgrid can be transmitted to the second input terminal of the detection and processing module 140 through the output terminal of the AC voltage detection module 120. Thus, the detection and processing module 140 can compare the voltage based on the second voltage signal Vgrid and the first voltage signal Vearth, and determine the AC grounding detection result based on the voltage comparison result Vout and the preset grounding abnormal voltage difference range.

[0055] Among them, the voltage comparison result Vout may include the voltage difference between the second voltage signal Vgrid and the first voltage signal Vearth. For example, this voltage difference may refer to the voltage difference obtained by subtracting the voltage value of the first voltage signal Vearth from the voltage value of the second voltage signal Vgrid (Vgrid - Vearth); the abnormal grounding voltage difference range can be set according to circuit safety regulations. For example, based on the Y capacitor in the circuit and according to the circuit safety detection requirements, the first voltage threshold aV and the second voltage threshold bV are used to determine the abnormal grounding voltage difference range. Specifically, the range where the voltage difference (Vgrid - Vearth) is greater than the preset first voltage threshold aV and less than the second voltage threshold bV can be determined as the abnormal grounding voltage difference range in advance. Thus, when the voltage difference obtained by subtracting the first voltage signal Vearth from the second voltage signal Vgrid (Vgrid - Vearth) is within the abnormal grounding voltage difference range, it is considered that the grounding is abnormal. That is, when aV < (Vgrid - Vearth) < bV, it is determined that the grounding is abnormal; and when the voltage difference (Vgrid - Vearth) is less than the first voltage threshold aV or the voltage difference (Vgrid - Vearth) is greater than the second voltage threshold bV, that is, when (Vgrid - Vearth) < aV or (Vgrid - Vearth) > bV, it is determined that the grounding is normal. It can be seen that in the embodiment of the present application, when the voltage difference (Vgrid - Vearth) between the second voltage signal Vgrid and the first voltage signal Vearth is not within the abnormal grounding voltage difference range, it is determined that the grounding is normal, so that the AC node detection can be realized without using a Hall current sensor, greatly reducing the cost of AC grounding detection and solving the problem of high detection cost caused by the need to connect a Hall current sensor with high precision in series in the grounding circuit in the existing AC grounding detection scheme.

[0056] In the embodiment of the present application, the first voltage threshold aV may refer to the minimum abnormal grounding voltage difference threshold set in advance based on the Y capacitor of the circuit according to circuit safety regulations; if the voltage difference (Vgrid - Vearth) obtained by subtracting the first voltage signal Vearth from the second voltage signal Vgrid is less than the preset first voltage threshold aV, it can be considered that the grounding is normal. For example, the first voltage threshold aV can be set to 0V, so that when the voltage difference (Vgrid - Vearth) is less than the preset first voltage threshold aV, that is, when (Vgrid - Vearth) < aV, it is determined that the grounding is normal, and the live wire Grid_L and the neutral wire Grid_N of the energy storage device are connected correctly, that is, the live wire Grid_L and the neutral wire Grid_N are not reversely connected. The specific value of the first voltage threshold aV can be set based on the circuit Y capacitor according to circuit safety regulations, and the embodiment of the present application does not make specific limitations on this.

[0057] The second voltage threshold bV can refer to the maximum grounding abnormal voltage difference threshold set in advance based on the Y capacitor of the circuit according to circuit safety regulations. The second voltage threshold bV is greater than the first voltage threshold aV. If the voltage difference (Vgrid - Vearth) obtained by subtracting the first voltage signal Vearth from the second voltage signal Vgrid is less than the preset second voltage threshold bV but greater than the first voltage threshold aV, that is, when the voltage difference (Vgrid - Vearth) is within the range of grounding abnormal voltage difference, it is determined to be a grounding abnormality. If the voltage difference (Vgrid - Vearth) is greater than the preset second voltage threshold bV, it can be considered that the grounding is normal. The live wire Grid_L and neutral wire Grid_N of the energy storage device are reversed. If the first voltage threshold aV is set to 0V, the second voltage threshold bV can be set to 160V based on the Y capacitor of the circuit according to circuit safety regulations. The specific value of the second voltage threshold bV can be set according to the circuit safety detection requirements. This application embodiment does not impose specific limitations on this.

[0058] In summary, the AC grounding detection circuit provided in this application includes: a ground voltage detection module 110, an AC voltage detection module 120, a bias power supply module 130, and a detection processing module 140. The ground voltage detection module 110 is electrically connected to the ground wire (Earth) of the energy storage device via its non-inverting input detection terminal, and to the neutral wire (Grid_N) via its inverting input detection terminal. The bias power supply terminal of the ground voltage detection module 110 is electrically connected to the output terminal of the bias power supply module 130. This allows the ground voltage detection module 110 to perform voltage sampling based on the bias voltage signal Voffset provided by the bias power supply module 130, obtaining the first voltage signal Vearth of the neutral wire (Grid_N) relative to the ground wire (Earth). This first voltage signal Vearth can be transmitted to the first input terminal of the detection processing module 140. The AC voltage detection module 120 is electrically connected to the live wire (Grid_L) via its non-inverting input detection terminal, and to the AC voltage detection module 140 via its inverting input detection terminal. The detection terminal is connected to the neutral wire Grid_N, and the bias power supply terminal of the AC voltage detection module 120 is electrically connected to the output terminal of the bias power supply module 130. This allows the AC voltage detection module 120 to sample the grid voltage based on the bias voltage signal Voffset provided by the bias power supply module 130, obtaining a second voltage signal Vgrid. The output terminal of the AC voltage detection module 120 is also electrically connected to the second input terminal of the detection processing module 140, allowing the second voltage signal Vgrid to be transmitted to the second input terminal of the detection processing module 140 through the output terminal of the AC voltage detection module 120. This enables the detection processing module 140 to compare the voltage based on the second voltage signal Vgrid and the first voltage signal Vearth, and determine the AC grounding detection result based on the voltage comparison result Vout, combined with a preset grounding abnormal voltage difference range. This solves the problem of high detection cost caused by the need to insert a high-precision Hall current sensor in series in the grounding circuit in the existing AC grounding detection scheme.

[0059] Furthermore, the AC grounding detection circuit provided in this application embodiment, through the detection processing module 140, compares the voltage based on the second voltage signal Vgrid and the first voltage signal Vearth. For example, the voltage value of the second voltage signal Vgrid can be subtracted from the voltage value of the first voltage signal Vearth, and the resulting voltage difference (Vgrid - Vearth) can be used as the voltage comparison result Vout, i.e., Vout = (Vgrid - Vearth). Therefore, by determining whether the voltage difference (Vgrid - Vearth) is within a preset grounding abnormal voltage difference range, it can be determined whether the grounding is normal. Thus, even if the voltage difference (Vgrid - Vearth) is not within the preset grounding abnormal voltage difference range, i.e., when the voltage difference (Vgrid - Vearth) exceeds the preset grounding abnormal voltage difference range, such as when the voltage difference (Vgrid - Vearth) is less than the first voltage threshold aV or greater than the second voltage threshold bV, ... Figure 2 As shown, good grounding is confirmed, meaning the grounding is normal. Further confirmation is made if the voltage difference (Vgrid - Vearth) is less than the first voltage threshold aV, indicating that the live wire Grid_L and neutral wire Grid_N are correctly connected (i.e., not reversed). Conversely, if the voltage difference (Vgrid - Vearth) is greater than the second voltage threshold bV, further confirmation is made that the live wire Grid_L and neutral wire Grid_N are reversed. If the voltage difference (Vgrid - Vearth) is within the preset abnormal grounding voltage difference range, i.e., if the voltage difference (Vgrid - Vearth) is greater than the first voltage threshold aV or the voltage difference (Vgrid - Vearth) is within the preset abnormal grounding voltage difference range, then... If the voltage (Vearth) is less than the second voltage threshold bV, a grounding anomaly is determined, which in turn indicates that the device's Earth wire is not grounded, posing a safety hazard. This eliminates the need for existing AC grounding detection schemes that require a high-precision but costly Hall current sensor in the grounding circuit, achieving accurate judgment of grounding quality. It saves detection costs while further improving the accuracy of AC grounding detection. This solves the problem of low accuracy in existing related technologies due to the inability to determine whether grounding is good when the live wire Grid_L and neutral wire Grid_N are reversed, even with reduced detection costs.

[0060] As can be seen, the detection and processing module 140 in this embodiment can specifically be used to determine the voltage difference (Vgrid - Vearth) based on the second voltage signal Vgrid and the first voltage signal Vearth. If the voltage difference (Vgrid - Vearth) is within a preset grounding abnormal voltage difference range, it is determined to be a grounding abnormality. If the voltage difference (Vgrid - Vearth) is not within the preset grounding abnormal voltage difference range, it is determined to be a normal grounding and the wiring of the live wire Grid_L and the neutral wire Grid_N is normal if the voltage difference (Vgrid - Vearth) is less than the first voltage threshold aV. Conversely, it is determined to be a normal grounding and the live wire Grid_L and the neutral wire Grid_N are reversed if the voltage difference (Vgrid - Vearth) is greater than the second voltage threshold bV. Here, the first voltage threshold aV is the minimum voltage difference (Vgrid - Vearth) threshold within the grounding abnormal voltage difference range, and the second voltage threshold bV is the maximum voltage difference (Vgrid - Vearth) threshold within the grounding abnormal voltage difference range.

[0061] In an optional embodiment of this application, to reduce detection costs, the ground voltage detection module 110 may include a differential amplifier circuit to sample the voltage between the neutral line Grid_N and the protective earth (PE), thereby generating a first voltage signal Vearth based on the voltage between the neutral line Grid_N and PE. Optionally, the ground voltage detection module 110 in this embodiment may include a first resistor R1, a second resistor, a third resistor, a fourth resistor R4, a first capacitor C1, a second capacitor C2, a third capacitor, and a first amplifier A1, so that the differential amplifier circuit composed of the first resistor R1, the second resistor, the third resistor, the fourth resistor R4, the first capacitor C1, the second capacitor C2, the third capacitor, and the first amplifier A1A can realize the function of the ground voltage detection module 110. The first terminal of the first resistor R1, the first terminal of the first capacitor C1, and the output terminal of the bias power supply module 130 are electrically connected. The second terminal of the first resistor R1, the second terminal of the first capacitor C1, and the non-inverting input terminal of the first amplifier A1 are electrically connected. This allows the bias voltage signal Voffset provided by the bias power supply module 130 to be transmitted to the first amplifier A1 through the RC circuit formed by the first resistor R1 and the first capacitor C1, providing bias power to the first amplifier A1. The first amplifier A1 can then sample and amplify the voltage between the neutral line Grid_N and the ground line Earth based on this bias power, and output the sampled and amplified signal as the first voltage signal Vearth to the detection and processing module 140, thus achieving voltage acquisition between the neutral line Grid_N and the ground line Earth. The output terminal of the first amplifier A1 is used to output the first voltage signal Vearth to the detection and processing module 140.

[0062] In a specific implementation, the non-inverting input terminal of the first amplifier A1 can be electrically connected to the ground line (Earth) through a second resistor. The number of second resistors can be one or at least two. For example, if the number of second resistors is greater than one, the non-inverting input terminal of the first amplifier A1 can be electrically connected to the ground line (Earth) through second resistors connected in series. An example is given with three second resistors. Figure 3As shown, in the case where the ground voltage detection module 110 can include three second resistors connected in series, the first terminal of the first second resistor R21 is electrically connected to the ground wire Earth, the first terminal of the second second resistor R22 is electrically connected to the second terminal of the first second resistor R21, the first terminal of the third second resistor R23 is electrically connected to the second terminal of the second second resistor R22, and the second terminal of the third second resistor R23 is electrically connected to the non-inverting input terminal of the first amplifier A1. The inverting input terminal of the first amplifier A1 can be electrically connected to the neutral wire Grid_N through the third resistor; the number of third resistors can be one or at least two. For example, if the number of third resistors is greater than one, the inverting input terminal of the first amplifier A1 can be electrically connected to the neutral wire Grid_N through third resistors connected in series. Taking a number of three third resistors as an example, as... Figure 3 As shown, in the case where the voltage-to-ground detection module 110 may include three third resistors connected in series, the first terminal of the first third resistor R31 is electrically connected to the neutral line Grid_N, the first terminal of the second third resistor R32 is electrically connected to the second terminal of the first third resistor R31, the first terminal of the third third resistor R33 is electrically connected to the second terminal of the second third resistor R32, and the second terminal of the third third resistor R33 is electrically connected to the inverting input terminal of the first amplifier A1. The number of third resistors and the number of second resistors can be specifically set according to the requirements of circuit safety regulations, and this embodiment does not impose specific limitations on this.

[0063] Furthermore, the third capacitor in the ground voltage detection module 110 can be disposed between the second resistor and the third resistor. Specifically, one end of the third capacitor is electrically connected to the second resistor, and the other end of the third capacitor is electrically connected to the third resistor. The number of third capacitors can be one or at least two, and this application embodiment does not limit this.

[0064] As an example of this application, such as Figure 3 As shown, taking an example where two third capacitors are placed between the third resistor and the second resistor, one end of the first third capacitor C31 is electrically connected to the first end of the third second resistor R23 and the second end of the second second resistor R22. The other end of the first third capacitor C31 is electrically connected to the first end of the third third resistor R33 and the second end of the second third resistor R32. One end of the second third capacitor C32 is electrically connected to the second end of the third second resistor R23 and the non-inverting input terminal of the first amplifier A1. The other end of the second third capacitor C32 is electrically connected to the second end of the third third resistor R33 and the inverting input terminal of the first amplifier A1. The inverting input terminal of the first amplifier A1 can be electrically connected to the output terminal of the first amplifier A1 through the fourth resistor R4 and the second capacitor C2, as shown. Figure 3As shown, the inverting input terminal of the first amplifier A1, the first terminal of the fourth resistor R4, and the first terminal of the second capacitor C2 are electrically connected. The second terminal of the fourth resistor R4, the second terminal of the second capacitor C2, the output terminal of the first amplifier A1, and the first input terminal of the detection and processing module 140 are electrically connected, so that the voltage to ground detection module 110 can output the first voltage signal Vearth to the detection and processing module 140 through the output terminal of the first amplifier A1. The power supply terminal of the first amplifier A1 is electrically connected to the power supply terminal VCC of the AC ground detection circuit, and the ground terminal of the first amplifier A1 is electrically connected to the reference ground GND of the AC ground detection circuit.

[0065] Of course, in addition to the first resistor R1, the second resistor, the third resistor, the fourth resistor R4, the first capacitor C1, the second capacitor C2, the third capacitor, and the first amplifier A1, the ground voltage detection module 110 in this embodiment may also include other circuit devices, such as the fourth capacitor C4. The first end of the fourth capacitor C4 is electrically connected to the power supply terminal of the first amplifier A1 and the power supply terminal VCC of the AC ground detection circuit, and the second end of the fourth capacitor C4 is electrically connected to the reference ground GND of the AC ground detection circuit.

[0066] Optionally, the AC voltage detection module 120 in this embodiment may include a fifth resistor R5, a sixth resistor, a seventh resistor, an eighth resistor R8, a fifth capacitor C5, a sixth capacitor, a seventh capacitor C7, and a second amplifier A2. The differential amplifier circuit composed of the fifth resistor R5, the sixth resistor, the seventh resistor, the eighth resistor R8, the fifth capacitor C5, the sixth capacitor, the seventh capacitor C7, and the second amplifier A2A can be used to detect the voltage between the neutral wire Grid_N and the live wire Grid_L. Based on the detected voltage between the neutral wire Grid_N and the live wire Grid_L, a second voltage signal Vgrid can be output and transmitted to the detection processing module 140. The first end of the fifth resistor R5, the first end of the fifth capacitor C5, and the output terminal of the bias power supply module 130 are electrically connected. The second end of the fifth resistor R5, the second end of the fifth capacitor C5, and the non-inverting input terminal of the second amplifier A2 are electrically connected. This allows the bias voltage signal Voffset provided by the bias power supply module 130 to be transmitted to the second amplifier A2 through the RC circuit formed by the fifth resistor R5 and the fifth capacitor C5, providing bias power to the second amplifier A2. The second amplifier A2 can then sample and amplify the AC voltage between the live wire Grid_L and the neutral wire Grid_N based on this bias power, and output the sampled and amplified signal as the second voltage signal Vgrid to the detection and processing module 140, thus realizing the voltage acquisition between the live wire Grid_L and the neutral wire Grid_N. The output terminal of the second amplifier A2 is used to output the second voltage signal Vgrid to the detection and processing module 140.

[0067] In a practical implementation, the non-inverting input of the second amplifier A2 can be electrically connected to the live wire Grid_L via a sixth resistor. The number of sixth resistors can be one or at least two. If the number of sixth resistors is greater than one, the non-inverting input of the second amplifier A2 can be electrically connected to the live wire Grid_L via sixth resistors connected in series. An example using three sixth resistors will be provided. Figure 4As shown, in the case where the AC voltage detection module 120 can include three sixth resistors connected in series, the first terminal of the first sixth resistor R61 is electrically connected to the live wire Grid_L, the first terminal of the second sixth resistor R62 is electrically connected to the second terminal of the first sixth resistor R61, the first terminal of the third sixth resistor R63 is electrically connected to the second terminal of the second sixth resistor R62, and the second terminal of the third sixth resistor R63 is electrically connected to the non-inverting input terminal of the second amplifier A2. The inverting input terminal of the second amplifier A2 can be electrically connected to the neutral wire Grid_N through a seventh resistor. The number of seventh resistors can be one or at least two. When the number of seventh resistors is greater than one, the inverting input terminal of the second amplifier A2 can be electrically connected to the neutral wire Grid_N through seventh resistors connected in series. Taking a number of seven resistors of three as an example, as follows... Figure 4 As shown, in the case where the AC voltage detection module 120 may include three seventh resistors connected in series, the first terminal of the first seventh resistor R71 is electrically connected to the neutral line Grid_N, the first terminal of the second seventh resistor R72 is electrically connected to the second terminal of the first seventh resistor R71, the first terminal of the third seventh resistor R73 is electrically connected to the second terminal of the second seventh resistor R72, and the second terminal of the third seventh resistor R73 is electrically connected to the inverting input terminal of the second amplifier A2. The number of seventh resistors and the number of sixth resistors can be set according to the requirements of circuit safety regulations, and this embodiment does not impose specific limitations on this.

[0068] Furthermore, the sixth capacitor in the AC voltage detection module 120 can be positioned between the sixth and seventh resistors. Specifically, one end of the sixth capacitor is electrically connected to the sixth resistor, and the other end is electrically connected to the seventh resistor. The number of sixth capacitors can be one or at least two. For example, two sixth capacitors are positioned between the seventh and sixth resistors. Figure 4 As shown, one end of the first sixth capacitor C61 is electrically connected to the first end of the third sixth resistor R63 and the second end of the second sixth resistor R62. The other end of the first sixth capacitor C61 is electrically connected to the first end of the third seventh resistor R73 and the second end of the second seventh resistor R72. One end of the second sixth capacitor C62 is electrically connected to the second end of the third sixth resistor R63 and the non-inverting input terminal of the second amplifier A2. The other end of the second sixth capacitor C62 is electrically connected to the second end of the third seventh resistor R73 and the inverting input terminal of the second amplifier A2. The inverting input terminal of the second amplifier A2 can be electrically connected to the output terminal of the second amplifier A2 through the eighth resistor R8 and the seventh capacitor C7, as shown. Figure 3As shown, the inverting input terminal of the second amplifier A2, the first terminal of the eighth resistor R8, and the first terminal of the seventh capacitor C7 are electrically connected. The second terminal of the eighth resistor R8, the second terminal of the seventh capacitor C7, the output terminal of the second amplifier A2, and the second input terminal of the detection and processing module 140 are electrically connected, so that the second voltage signal Vgrid can be transmitted to the detection and processing module 140 through the output terminal of the second amplifier A2. The detection and processing module 140 then compares the voltage based on the second voltage signal Vgrid and the first voltage signal Vearth, and subtracts the first voltage signal Vearth from the second voltage signal Vgrid. Then, by judging whether the voltage difference (Vgrid - Vearth) is less than the first voltage difference (Vgrid - Vearth) aV and whether the voltage difference (Vgrid - Vearth) is greater than the second voltage threshold bV, it can determine whether the grounding is abnormal.

[0069] In an optional embodiment of this application, the detection processing module 140 may include a controller 1401, such as Figure 5As shown, the first input terminal of the controller 1401 is electrically connected to the output terminal of the ground voltage detection module 110, and the second input terminal of the controller 1401 is connected to the output terminal of the AC voltage detection module 120. This allows the controller 1401 to obtain a voltage difference (Vgrid - Vearth) by subtracting the voltage value of the first voltage signal Vearth from the voltage value of the second voltage signal Vgrid. The controller can then determine whether the voltage difference (Vgrid - Vearth) is within a preset grounding abnormal voltage difference range by judging whether the voltage difference (Vgrid - Vearth) is less than a first voltage threshold aV and whether the voltage difference (Vgrid - Vearth) is greater than a second voltage threshold bV. Based on the judgment result, the controller can determine whether the grounding is normal and whether the live wire Grid_L and the neutral wire Grid_N are reversed. Specifically, if the voltage difference (Vgrid - Vearth) is less than the first voltage threshold aV, it can be considered that the voltage difference (Vgrid - Vearth) is not within the preset abnormal grounding voltage difference range, and the grounding can be determined to be normal, and the connection of the live wire Grid_L and the neutral wire Grid_N is normal; if the voltage difference (Vgrid - Vearth) is greater than the second voltage threshold bV, it can be considered that the voltage difference (Vgrid - Vearth) is not within the preset abnormal grounding voltage difference range, and the grounding can be determined to be normal, and the live wire Grid_L and the neutral wire Grid_N are reversed; if the voltage difference (Vgrid - Vearth) is not less than the first voltage threshold aV and not greater than the second voltage threshold bV, it can be considered that the voltage difference (Vgrid - Vearth) is within the preset abnormal grounding voltage difference range, and the grounding can be determined to be abnormal.

[0070] As can be seen, the controller in this embodiment can be specifically used to: subtract the voltage value of the first voltage signal Vearth from the voltage value of the second voltage signal Vgrid to obtain the voltage difference (Vgrid - Vearth); if the voltage difference (Vgrid - Vearth) is less than the first voltage threshold aV, then the grounding is determined to be normal, and the live wire Grid_L and the neutral wire Grid_N are connected normally; if the voltage difference (Vgrid - Vearth) is greater than the second voltage threshold bV, then the grounding is determined to be normal, and the live wire Grid_L and the neutral wire Grid_N are reversed; if the voltage difference (Vgrid - Vearth) is not less than the first voltage threshold aV and not greater than the second voltage threshold bV, then the grounding is determined to be abnormal.

[0071] Of course, in addition to using a controller to determine whether the voltage difference (Vgrid - Vearth) between the second voltage signal Vgrid and the first voltage signal Vearth is within the preset grounding abnormal voltage difference range, this application embodiment can also use other methods to determine whether the voltage difference (Vgrid - Vearth) is within the preset grounding abnormal voltage difference range, so as to determine whether the grounding is normal based on the judgment result and whether the neutral wire Grid_N and the live wire Grid_L are reversed under the condition of normal grounding.

[0072] In another optional embodiment of this application, such as Figure 6 As shown, the detection processing module 140 includes: a voltage comparator unit 1402 and a detection result output unit 1403; the inverting input terminal of the voltage comparator unit 1402 is electrically connected to the output terminal of the ground voltage detection module 110, the non-inverting input terminal of the voltage comparator unit 1402 is connected to the output terminal of the AC voltage detection module 120, and the output terminal of the voltage comparator unit 1402 is electrically connected to the input terminal of the detection result output unit 1403, so that the voltage comparator unit 1402 can subtract the voltage value of the first voltage signal Vearth from the voltage value of the second voltage signal Vgrid, and output the voltage difference (Vgrid - Vearth) to the detection result output unit 1403, so that the detection result output can output a first detection result when the voltage difference (Vgrid - Vearth) is less than the first voltage threshold aV, the first detection result is used to indicate that the grounding is normal and the wiring of the live wire Grid_L and the neutral wire Grid_N is normal; or, when the voltage difference (Vgrid - Vearth) is less than the first voltage threshold aV, the first detection result is used to output a first detection result, which indicates that the grounding is normal and the wiring of the live wire Grid_L and the neutral wire Grid_N is normal; or, when the voltage difference (Vgrid - Vearth) is less than the first voltage threshold aV, the first detection result is used to output a first detection result, which indicates that the grounding is normal and the wiring of the live wire Grid_L and the neutral wire Grid_N is normal; If the voltage difference (Vgrid - Vearth) is greater than the second voltage threshold bV, a second detection result is output, which indicates that the grounding is normal and the live wire Grid_L and the neutral wire Grid_N are reversed; or, if the voltage difference (Vgrid - Vearth) is not less than the first voltage threshold aV and not greater than the second voltage threshold bV, a third detection result is output, which indicates that the grounding is abnormal.

[0073] As can be seen, the voltage comparator unit 1402 in this embodiment is used to subtract the voltage value of the first voltage signal Vearth from the voltage value of the second voltage signal Vgrid, and output the voltage difference (Vgrid - Vearth). Optionally, the voltage comparator unit 1402 includes a first comparator U1, a ninth resistor R9, a tenth resistor R10, an eleventh resistor R11, a twelfth resistor R12, a thirteenth resistor R13, an eighth capacitor C8, a ninth capacitor C9, a tenth capacitor C10, an eleventh capacitor C11, and a twelfth capacitor C12; wherein, the first terminal of the ninth resistor R9, the first terminal of the eighth capacitor C8, and the output terminal of the bias power supply module 130 are electrically connected; the second terminal of the ninth resistor R9, the second terminal of the eighth capacitor C8, the first terminal of the tenth capacitor C10, the second terminal of the tenth resistor R10, and the non-inverting input terminal of the first comparator U1 are electrically connected; the first terminal of the tenth resistor R10 is electrically connected to the output terminal of the AC voltage detection module 120; and the inverting input terminal of the first comparator U1, the second terminal of the eleventh resistor R11, the first terminal of the twelfth resistor R12, the second terminal of the tenth capacitor C10, and the twelfth capacitor C12 are electrically connected. The first terminal of capacitor C9 is electrically connected to the ground voltage detection module 110. The first terminal of resistor R11 is electrically connected to the output terminal of the eleventh resistor R11. The second terminal of resistor R12, the second terminal of capacitor C9, the output terminal of comparator U1, and the first terminal of resistor R13 are electrically connected. The second terminal of resistor R13, the first terminal of capacitor C11, and the input terminal of detection result output unit 1403 are electrically connected. The first terminal of capacitor C12, the power supply terminal of comparator U1, and the power supply terminal VCC of AC ground detection circuit are electrically connected. The second terminal of capacitor C12, the second terminal of capacitor C11, and the reference ground GND of AC ground detection circuit are electrically connected. Thus, voltage comparison can be performed by comparator U1 to subtract the voltage value of the first voltage signal Vearth from the voltage value of the second voltage signal Vgrid to obtain the voltage difference (Vgrid). -Vearth), and can use the voltage difference (Vgrid - Vearth) as the voltage comparison result Vout, and output it to the detection result output unit 1403. The detection result output unit 1403 can determine whether the grounding is normal based on the voltage difference (Vgrid - Vearth) and the preset grounding abnormal voltage difference range, and output the corresponding grounding detection result based on the comparison result. This allows the user to determine whether the grounding is normal through the grounding detection result, and to determine whether the neutral wire Grid_N and the live wire Grid_L are reversed under the condition that the grounding is normal, thereby further improving circuit safety.

[0074] Specifically, the grounding detection results in this embodiment can be divided into a first detection result, a second detection result, and a third detection result. The first detection result indicates that the grounding is normal and the live wire Grid_L and the neutral wire Grid_N are connected correctly. The second detection result indicates that the grounding is normal and the live wire Grid_L and the neutral wire Grid_N are reversed. The third detection result indicates that the grounding is abnormal. Therefore, the detection result output unit 1403 in this embodiment can be specifically used to: output a first detection result when the voltage difference (Vgrid - Vearth) is less than the first voltage threshold aV; or output a second detection result when the voltage difference (Vgrid - Vearth) is greater than the second voltage threshold bV; or output a third detection result when the voltage difference (Vgrid - Vearth) is not less than the first voltage threshold aV and not greater than the second voltage threshold bV.

[0075] In an optional embodiment of this application, the detection result output unit 1403 can compare the voltage difference (Vgrid - Vearth) with the maximum and minimum grounding abnormal voltage difference thresholds within the grounding abnormal voltage difference range using a comparator, so as to output the corresponding grounding detection result based on the comparison result.

[0076] Optional, such as Figure 7As shown, the detection result output unit 1403 includes a second comparator U2, a third comparator U3, a fourth comparator U4, a fifth comparator U5, a first diode D1, a second diode D2, a third diode D3, a fourth diode D4, a first pull-up resistor R41, a second pull-up resistor R42, a third pull-up resistor R43, a fourth pull-up resistor R44, a fourteenth resistor R14, a fifteenth resistor R15, a sixteenth resistor R16, a seventeenth resistor R17, a thirteenth capacitor C13, a fourteenth capacitor C14, a fifteenth capacitor C15, and a first transistor Q1; wherein, the non-inverting input terminal of the second comparator U2, the third comparator U3, the fourth comparator U4, the fifth comparator U5, the fifth comparator U5, the sixth comparator U4, the seventh comparator U5, the seventh comparator U4, the eighth comparator U5, the ninth comparator U4, the tenth comparator U5, the eleventh comparator U4, the thirteenth capacitor C13, the fourteenth capacitor C14, the fifteenth capacitor C15, and a first transistor Q1; wherein, the non-inverting input terminal of the second comparator U2, the fifth comparator U3, the sixth comparator U4, the seventh comparator U5, the tenth comparator U4, the tenth comparator U4, the tenth comparator U5, the seventh comparator U4, the tenth comparator U4, the tenth comparator U4, the tenth comparator U5 ... The inverting input of the third comparator U3, the non-inverting input of the fourth comparator U4, the inverting input of the fifth comparator U5, and the output of the voltage comparator unit 1402 are electrically connected. The power supply terminal of the second comparator U2, the first terminal of the thirteenth capacitor C13, the first terminal of the first pull-up resistor R41, the first terminal of the second pull-up resistor R42, the power supply terminal of the fourth comparator U4, the first terminal of the fourteenth capacitor C14, the first terminal of the third pull-up resistor R43, the first terminal of the fourth pull-up resistor R44, the first terminal of the seventeenth resistor R17, and the AC grounding detection circuit are also connected. The power supply terminal VCC is electrically connected. The inverting input terminal of the second comparator U2 is electrically connected to the first voltage terminal. The output terminal of the second comparator U2, the second terminal of the first pull-up resistor R41, and the anode of the first diode D1 are electrically connected. The cathodes of the first diode D1, the second diode D2, the third diode D3, the fourth diode D4, and the first terminal of the fifteenth resistor R15 are electrically connected. The first voltage terminal is used to provide the first reference signal VA1 corresponding to the first voltage threshold aV. The non-inverting input terminal of the third comparator U3 is electrically connected to the second voltage terminal. The output terminal of comparator U3, the second terminal of the second pull-up resistor R42, and the anode of the second diode D2 are electrically connected. The second voltage terminal is used to provide a second reference signal VA2 corresponding to the first voltage threshold aV. The voltage of the first reference signal VA1 is higher than the voltage of the second reference signal VA2. The inverting input terminal of the fourth comparator U4 is electrically connected to the third voltage terminal. The output terminal of the fourth comparator U4, the second terminal of the third pull-up resistor R43, and the anode of the third diode D3 are electrically connected. The third voltage terminal is used to provide a third reference signal VB1 corresponding to the second voltage threshold bV.The non-inverting input of the fifth comparator U5 is electrically connected to the fourth voltage terminal. The output of the fifth comparator U5, the second terminal of the fourth pull-up resistor R44, and the anode of the fourth diode D4 are electrically connected. The fourth voltage terminal is used to provide a fourth reference signal VB2 corresponding to the second voltage threshold bV. The voltage of the fourth reference signal VB2 is higher than the voltage of the second reference signal VA2, and the voltage of the fourth reference signal VB2 is lower than the voltage of the third reference signal VB1. The second terminal of the fifteenth resistor R15, the first terminal of the sixteenth resistor R16, the first terminal of the fifteenth capacitor C15, and the control terminal of the first transistor Q1 are electrically connected. The first terminal of the first transistor Q1, the second terminal of the seventeenth resistor R17, and the TRIP output terminal of the detection result output unit 1403 are electrically connected. The second terminal of the sixteenth resistor R16, the second terminal of the fifteenth capacitor C15, the second terminal of the first transistor Q1, the ground terminal of the second comparator U2, the ground terminal of the fourth comparator U4, and the reference ground GND of the AC ground detection circuit are electrically connected.

[0077] Wherein, the first reference signal VA1 and the second reference signal VA2 can represent the first voltage threshold aV; the third reference signal VB1 and the fourth reference signal VB2 can represent the second voltage threshold bV. In a specific implementation, the voltage at the power supply terminal VCC of the AC grounding detection circuit can be divided using three voltage-dividing resistors to generate the first reference signal VA1 and the second reference signal VA2, and the voltage at the power supply terminal VCC of the AC grounding detection circuit can be divided using another three voltage-dividing resistors to generate the third reference signal VB1 and the fourth reference signal VB2, as follows. Figure 7 As shown, voltage division can be achieved by connecting the first voltage divider resistor R101, the second voltage divider resistor R102, and the third voltage divider resistor R103 in series to generate the first reference signal VA1 and the second reference signal VA2; and voltage division can be achieved by connecting the fourth voltage divider resistor R104, the fifth voltage divider resistor R105, and the sixth voltage divider resistor R106 in series to generate the third reference signal VB1 and the fourth reference signal VB2. The resistance values ​​of the first voltage divider resistor R101, the second voltage divider resistor R102, the third voltage divider resistor R103, the fourth voltage divider resistor R104, the fifth voltage divider resistor R105, and the sixth voltage divider resistor R106 can be set according to the circuit detection requirements, and this embodiment does not impose specific limitations on this.

[0078] When the voltage difference (Vgrid - Vearth) is less than the first voltage threshold aV, or when the voltage difference (Vgrid - Vearth) is greater than the second voltage threshold bV, that is, when (Vgird - Vearth) < aV or (Vgird - Vearth) > bV, the level of the node TZ1 connected to the cathodes of the first diode D1, the second diode D2, the third diode D3, the fourth diode D4, and the first end of the fifteenth resistor R15 is high. The first transistor Q1 conducts, causing the output terminal TRIP of the detection result output unit 1403 to be grounded through the conducting first transistor Q1. At this time, the level of the output terminal TRIP of the detection result output unit 1403 is low, indicating normal grounding. At this time, it is possible to determine whether the neutral wire and the live wire are reversed by checking the lighting conditions of the four diodes, namely the first diode D1, the second diode D2, the third diode D3, and the fourth diode D4. For example, when the first diode D1, the third diode D3, and the fourth diode D4 do not emit light, and only the second diode D2 emits light, it can be determined that the connection of the neutral wire and the live wire is normal. When the first diode D1 and the third diode D3 both emit light, and the second diode D2 and the fourth diode D4 do not emit light, it is determined that the neutral wire and the live wire are reversed. When the voltage difference (Vgrid - Vearth) is not less than the first voltage threshold aV and is not greater than the second voltage threshold bV, that is, when aV < (Vgird - Vearth) < bV, the level of the output terminal TRIP of the detection result output unit 1403 is high, indicating abnormal grounding.

[0079] Such as Figure 8As shown, this application provides an AC grounding detection system 800, which includes an AC grounding detection circuit 810 and a power device 820. The power supply line of the power device 820 is electrically connected to the power supply line of the AC grounding detection circuit 810, thereby enabling AC power to supply power to the power device 820 and ensuring its normal operation. The AC grounding detection circuit 810 can be any of the AC grounding detection circuits described in the above embodiments of this application, allowing the AC grounding detection system 800 to obtain the first voltage difference between the neutral wire Grid_N and the ground wire Earth by performing voltage sampling through the ground voltage detection module 110. The voltage signal Vearth is sampled by the AC voltage detection module 120 to obtain the second voltage signal Vgrid. The detection and processing module 140 can then compare the voltage based on the second voltage signal Vgrid and the first voltage signal Vearth. Based on the voltage comparison result Vout, and combined with the preset grounding abnormal voltage difference range, the AC grounding detection result is determined. This solves the problem that existing related technologies cannot accurately determine whether the grounding is good when the obtained N-line to ground voltage value inside the equipment is reversed when the live wire Grid_L and the neutral wire Grid_N are reversed. This further improves the accuracy of AC grounding detection while saving detection costs.

[0080] In a specific implementation, the AC grounding detection circuit provided in this application can be applied to energy storage devices. The energy storage device can obtain a first voltage signal, Vearth, from the neutral wire Grid_N to the ground wire Earth by voltage sampling through the ground voltage detection module 110. It can also obtain a second voltage signal, Vgrid, by sampling the grid voltage through the AC voltage detection module 120. The detection processing module 140 can then compare the second voltage signal Vgrid with the first voltage signal Vearth. Based on the voltage comparison result Vout, and combined with a preset grounding abnormal voltage difference range, the AC grounding detection result is determined. This solves the problem in existing related technologies where the obtained N-line to ground voltage value cannot accurately determine whether the grounding is good when the live wire Grid_L and neutral wire Grid_N are reversed. This saves detection costs while further improving the accuracy of AC grounding detection.

[0081] Energy storage devices can refer to devices equipped with energy storage batteries. For example... Figure 9As shown in the illustration, this application also provides an energy storage device 900, which includes the AC grounding detection circuit 810 and the power-consuming device 820 as described in any of the above embodiments. The power supply line of the power-consuming device 820 is electrically connected to the power supply line of the AC grounding detection circuit 810, thereby enabling AC power to supply the power-consuming device 820 and ensuring its normal operation. In specific implementation, the energy storage device 900 can perform AC grounding detection through the AC grounding detection circuit 810, solving the problem in existing related technologies where the obtained N-line to ground voltage value cannot accurately determine whether the grounding is good when the live wire Grid_L and neutral wire Grid_N are reversed. This saves detection costs while further improving the accuracy of AC grounding detection.

[0082] The system and device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs.

[0083] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus a general-purpose hardware platform, or of course by hardware.

[0084] Based on this understanding, the above technical solutions, or the parts that contribute to the relevant technologies, can be embodied in the form of software products. These computer software products can be stored in computer-readable storage media, such as ROM / RAM, magnetic disks, optical disks, etc., and include several instructions to cause a computer device (which may be a personal computer, a server, or a network device, etc.) to execute the methods described in various embodiments or some parts of the embodiments.

[0085] It should be understood that the terminology used herein is for the purpose of describing particular exemplary embodiments only and is not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “described” as used herein may also include the plural forms. The terms “comprising,” “including,” “containing,” and “having” are inclusive and therefore indicate the presence of the stated features, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, elements, components, and / or combinations thereof. The method steps, processes, and operations described herein are not construed as requiring them to be performed in a particular order described or illustrated unless the order of performance is explicitly indicated. It should also be understood that additional or alternative steps may be used.

[0086] The above description is merely a specific embodiment of the present invention, enabling those skilled in the art to understand or implement the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. An AC grounding detection circuit, characterized in that, include: Ground voltage detection module, AC voltage detection module, bias power supply module, and detection processing module; The in-phase input detection terminal of the ground voltage detection module is electrically connected to the ground wire of the energy storage device; the inverting input detection terminal of the ground voltage detection module, the inverting input detection terminal of the AC voltage detection module, and the neutral wire are electrically connected; the output terminal of the ground voltage detection module is electrically connected to the first input terminal of the detection processing module; the in-phase input detection terminal of the AC voltage detection module is electrically connected to the live wire; the output terminal of the AC voltage detection module is electrically connected to the second input terminal of the detection processing module; and the bias power supply terminal of the AC voltage detection module, the bias power supply terminal of the ground voltage detection module, and the output terminal of the bias power supply module are electrically connected. The ground voltage detection module is used to perform voltage sampling based on the bias voltage signal provided by the bias power supply module to obtain the first voltage signal between the neutral wire and the ground wire. The AC voltage detection module is used to sample the grid voltage based on the bias voltage signal to obtain a second voltage signal; The detection and processing module is used to determine the voltage difference based on the second voltage signal and the first voltage signal; if the voltage difference is within a preset grounding abnormal voltage difference range, it is determined to be a grounding abnormality; or, if the voltage difference is not within the preset grounding abnormal voltage difference range, it is determined to be a normal grounding and the connection of the live wire and the neutral wire is normal when the voltage difference is less than the first voltage threshold, and it is determined to be a normal grounding and the connection of the live wire and the neutral wire is reversed when the voltage difference is greater than the second voltage threshold.

2. The AC grounding detection circuit according to claim 1, characterized in that, The voltage to ground detection module includes a first resistor, a second resistor, a third resistor, a fourth resistor, a first capacitor, a second capacitor, a third capacitor, and a first amplifier; The first end of the first resistor, the first end of the first capacitor, and the output end of the bias power supply module are electrically connected, and the second end of the first resistor, the second end of the first capacitor, and the non-inverting input end of the first amplifier are electrically connected. The non-inverting input terminal of the first amplifier is electrically connected to the ground wire through the second resistor, and the inverting input terminal of the first amplifier is electrically connected to the neutral wire through the third resistor. The inverting input terminal of the first amplifier, the first end of the fourth resistor, and the first end of the second capacitor are electrically connected. The second end of the fourth resistor, the second end of the second capacitor, the output terminal of the first amplifier, and the first input terminal of the detection and processing module are electrically connected. One end of the third capacitor is electrically connected to the second resistor, and the other end of the third capacitor is electrically connected to the third resistor.

3. The AC grounding detection circuit according to claim 2, characterized in that, The voltage to ground detection module also includes a fourth capacitor. The first end of the fourth capacitor is electrically connected to the power supply terminal of the first amplifier and the power supply terminal of the AC ground detection circuit. The second end of the fourth capacitor is electrically connected to the reference ground of the AC ground detection circuit.

4. The AC grounding detection circuit according to claim 1, characterized in that, The AC voltage detection module includes a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, a fifth capacitor, a sixth capacitor, a seventh capacitor, and a second amplifier; The first end of the fifth resistor, the first end of the fifth capacitor, and the output end of the bias power supply module are electrically connected; the second end of the fifth resistor, the second end of the fifth capacitor, and the non-inverting input end of the second amplifier are electrically connected. The non-inverting input terminal of the second amplifier is electrically connected to the live wire through the sixth resistor, and the inverting input terminal of the second amplifier is electrically connected to the neutral wire through the seventh resistor. The inverting input terminal of the second amplifier, the first end of the eighth resistor, and the first end of the seventh capacitor are electrically connected. The second end of the eighth resistor, the second end of the seventh capacitor, the output terminal of the second amplifier, and the second input terminal of the detection and processing module are electrically connected. One end of the sixth capacitor is electrically connected to the sixth resistor, and the other end of the sixth capacitor is electrically connected to the seventh resistor.

5. The AC grounding detection circuit according to any one of claims 1 to 4, characterized in that, The detection and processing module includes: a controller; The first input terminal of the controller is electrically connected to the output terminal of the ground voltage detection module, and the second input terminal of the controller is connected to the output terminal of the AC voltage detection module. The controller is specifically used to subtract the voltage value of the first voltage signal from the voltage value of the second voltage signal to obtain the voltage difference; if the voltage difference is less than the first voltage threshold, it is determined that the grounding is normal and the connection between the live wire and the neutral wire is normal; if the voltage difference is greater than the second voltage threshold, it is determined that the grounding is normal and the live wire and the neutral wire are reversed; if the voltage difference is not less than the first voltage threshold and not greater than the second voltage threshold, it is determined that the grounding is abnormal.

6. The AC grounding detection circuit according to any one of claims 1 to 4, characterized in that, The detection processing module includes: a voltage comparator unit and a detection result output unit; The inverting input terminal of the voltage comparator unit is electrically connected to the output terminal of the voltage to ground detection module, the non-inverting input terminal of the voltage comparator unit is connected to the output terminal of the AC voltage detection module, and the output terminal of the voltage comparator unit is electrically connected to the input terminal of the detection result output unit. The voltage comparator unit is used to subtract the voltage value of the first voltage signal from the voltage value of the second voltage signal, and output the voltage difference; The detection result output unit is used to output a first detection result when the voltage difference is less than the first voltage threshold, the first detection result indicating that the grounding is normal and the live wire and the neutral wire are connected normally; or, when the voltage difference is greater than the second voltage threshold, output a second detection result indicating that the grounding is normal and the live wire and the neutral wire are reversed; or, when the voltage difference is not less than the first voltage threshold and not greater than the second voltage threshold, output a third detection result indicating that the grounding is abnormal.

7. The AC grounding detection circuit according to claim 6, characterized in that, The voltage comparator unit includes a first comparator, a ninth resistor, a tenth resistor, an eleventh resistor, a twelfth resistor, a thirteenth resistor, an eighth capacitor, a ninth capacitor, a tenth capacitor, an eleventh capacitor, and a twelfth capacitor; Specifically, the first end of the ninth resistor, the first end of the eighth capacitor, and the output end of the bias power supply module are electrically connected; the second end of the ninth resistor, the second end of the eighth capacitor, the first end of the tenth capacitor, the second end of the tenth resistor, and the non-inverting input end of the first comparator are electrically connected; the first end of the tenth resistor is electrically connected to the output end of the AC voltage detection module; the inverting input end of the first comparator, the second end of the eleventh resistor, the first end of the twelfth resistor, the second end of the tenth capacitor, and the first end of the ninth capacitor are electrically connected; the first end of the eleventh resistor is electrically connected to the output end of the voltage to ground detection module; the second end of the twelfth resistor, the second end of the ninth capacitor, the output end of the first comparator, and the first end of the thirteenth resistor are electrically connected; and the second end of the thirteenth resistor, the first end of the eleventh capacitor, and the input end of the detection result output unit are electrically connected. The first terminal of the twelfth capacitor, the power supply terminal of the first comparator, and the power supply terminal of the AC ground detection circuit are electrically connected, and the second terminal of the twelfth capacitor, the second terminal of the eleventh capacitor, and the reference ground of the AC ground detection circuit are electrically connected.

8. The AC grounding detection circuit according to claim 6, characterized in that, The detection result output unit includes a second comparator, a third comparator, a fourth comparator, a fifth comparator, a first diode, a second diode, a third diode, a fourth diode, a first pull-up resistor, a second pull-up resistor, a third pull-up resistor, a fourth pull-up resistor, a fourteenth resistor, a fifteenth resistor, a sixteenth resistor, a seventeenth resistor, a thirteenth capacitor, a fourteenth capacitor, a fifteenth capacitor, and a first transistor; The non-inverting input of the second comparator, the inverting input of the third comparator, the non-inverting input of the fourth comparator, the inverting input of the fifth comparator, and the output of the voltage comparator unit are electrically connected. The power supply terminal of the second comparator, the first terminal of the thirteenth capacitor, the first terminal of the first pull-up resistor, the first terminal of the second pull-up resistor, the power supply terminal of the fourth comparator, the first terminal of the fourteenth capacitor, the first terminal of the third pull-up resistor, the first terminal of the fourth pull-up resistor, the first terminal of the seventeenth resistor, and the power supply terminal of the AC grounding detection circuit are electrically connected. The inverting input of the second comparator is electrically connected to the first voltage terminal. The output of the second comparator, the second terminal of the first pull-up resistor, and the anode of the first diode are electrically connected. The cathodes of the first diode, the second diode, the third diode, the fourth diode, and the first terminal of the fifteenth resistor are electrically connected. The first voltage terminal is used to provide a first reference signal corresponding to the first voltage threshold. The non-inverting input terminal of the third comparator is electrically connected to the second voltage terminal, and the output terminal of the third comparator, the second terminal of the second pull-up resistor, and the anode of the second diode are electrically connected. The second voltage terminal is used to provide a second reference signal corresponding to the first voltage threshold, and the voltage of the first reference signal is higher than the voltage of the second reference signal. The inverting input terminal of the fourth comparator is electrically connected to the third voltage terminal, and the output terminal of the fourth comparator, the second terminal of the third pull-up resistor, and the anode of the third diode are electrically connected. The third voltage terminal is used to provide a third reference signal corresponding to the second voltage threshold. The non-inverting input terminal of the fifth comparator is electrically connected to the fourth voltage terminal. The output terminal of the fifth comparator, the second terminal of the fourth pull-up resistor, and the anode of the fourth diode are electrically connected. The fourth voltage terminal is used to provide a fourth reference signal corresponding to the second voltage threshold. The voltage of the fourth reference signal is higher than the voltage of the second reference signal, and the voltage of the fourth reference signal is lower than the voltage of the third reference signal. The second terminal of the fifteenth resistor, the first terminal of the sixteenth resistor, the first terminal of the fifteenth capacitor, and the control terminal of the first transistor are electrically connected. The first terminal of the first crystal, the second terminal of the seventeenth resistor, and the output terminal of the detection result output unit are electrically connected. The second terminal of the sixteenth resistor, the second terminal of the fifteenth capacitor, the second terminal of the first transistor, the ground terminal of the second comparator, the ground terminal of the fourth comparator, and the reference ground of the AC ground detection circuit are electrically connected.

9. An AC grounding detection system, characterized in that, It includes an AC grounding detection circuit as described in any one of claims 1 to 8 and an electrical component electrically connected to the AC grounding detection circuit.

10. An energy storage device, characterized in that, It includes an AC grounding detection circuit as described in any one of claims 1 to 8 and an electrical component electrically connected to the AC grounding detection circuit.

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