AC charging pile grounding detection device and AC charging pile

Abstract

This invention provides an AC charging pile grounding detection device and an AC charging pile. The AC charging pile grounding detection device includes a hybrid voltage divider network based on Y5P and X7R, an optocoupler isolation module, and a control module. The input end of the hybrid voltage divider network is connected to the power grid to which the AC charging pile is connected, and the output end is connected to the optocoupler isolation module. The optocoupler isolation module is also connected to the control module. The hybrid voltage divider network is used to acquire voltage detection signals; the optocoupler isolation module is used to optically isolate the voltage detection signals and input them to the control module. This invention solves the problem of voltage division anomalies caused by temperature drift and voltage fluctuations through the hybrid voltage divider network and optocoupler isolation module, improving the accuracy of grounding detection.

Description

Technical Field

[0001] This utility model relates to the field of AC charging pile technology, and in particular to an AC charging pile grounding detection device and an AC charging pile. Background Technology

[0002] The grounding detection circuit of a charging pile is a crucial component for ensuring its safe operation. Its primary function is to detect whether the grounding of the charging pile is normal, preventing safety issues caused by faults such as leakage. However, existing grounding detection circuits in TT / TN power grid systems have the following shortcomings under extreme operating conditions: ambient temperature -30~85℃, grid voltage fluctuation of 184~276Vac, and neutral point offset of 30Vac.

[0003] (1) Temperature drift effect: The capacitance value of the front-end safety capacitor will change drastically with temperature. Under different temperature conditions, the capacitance value will decrease by up to 82% (e.g., the capacitance value is only 18% at low temperature -30℃), which will cause the voltage divider network to be unbalanced, the PE fault detection signal to be abnormal, and the system's missed detection rate to be as high as 68%.

[0004] (2) Impact of voltage fluctuations: When the grid voltage fluctuations exceed the design threshold range (±20%), PE faults are missed, with a typical missed rate of up to 25%.

[0005] (3) Neutral point offset interference: The 30Vac N-PE voltage difference is directly superimposed on the detection signal, causing the system to misjudge it as a ground fault, with a false alarm rate as high as 40%;

[0006] (4) Risk of multiple factors: When temperature drift, voltage fluctuation and neutral point shift work together, the conflict of decision logic leads to a sharp increase in the system misjudgment rate (e.g., the misjudgment rate reaches 80% in the high temperature + low voltage fluctuation scenario).

[0007] In summary, the existing grounding detection circuits in TT / TN power grid systems are prone to false alarms or failure to report under extreme operating conditions. Utility Model Content

[0008] In view of the shortcomings of the prior art described above, the technical problem to be solved by this utility model is to provide an AC charging pile grounding detection device and an AC charging pile, so as to solve the problem of high false detection rate of grounding detection circuit in the prior art.

[0009] To address the aforementioned technical problems, this utility model provides an AC charging pile grounding detection device, comprising: a hybrid voltage divider network based on Y5P and X7R, an optocoupler isolation module, and a control module; wherein, the input end of the hybrid voltage divider network is connected to the power grid to which the AC charging pile is connected, and the output end is connected to the optocoupler isolation module; the optocoupler isolation module is also connected to the control module; the hybrid voltage divider network is used to acquire voltage detection signals; the optocoupler isolation module is used to perform optocoupler isolation on the voltage detection signals and input them to the control module.

[0010] In one embodiment of the present invention, the input terminals of the hybrid voltage divider network include: a live wire input terminal, a ground wire input terminal, and a neutral wire input terminal; wherein, the live wire input terminal is connected to the live wire of the power grid, the ground wire input terminal is connected to the ground wire of the power grid, and the neutral wire input terminal is connected to the neutral wire of the power grid.

[0011] In one embodiment of this utility model, the hybrid voltage divider network includes: a first Y5P capacitor, a first Y5V capacitor, an X2 capacitor, and a common-mode inductor; wherein, one end of the first Y5P capacitor is connected to the neutral wire input terminal, and the other end is connected to one end of the first Y5V capacitor; the other end of the first Y5V capacitor is connected to the live wire input terminal; the ground wire input terminal is connected between the first Y5P capacitor and the first Y5V capacitor; one end of the first Y5P capacitor is also connected to one end of the X2 capacitor, and the other end of the first Y5V capacitor is also connected to the other end of the X2 capacitor; one end of the X2 capacitor is also connected to the first end of the common-mode inductor, and the other end of the X2 capacitor is also connected to the second end of the common-mode inductor through the first inductor.

[0012] In one embodiment of this utility model, the hybrid voltage divider network further includes: a second Y5P capacitor and a second Y5V capacitor; wherein, one end of the second Y5V capacitor is connected to the third end of the common-mode inductor, the other end of the second Y5V capacitor is connected to one end of the second Y5P capacitor, and the other end of the second Y5P capacitor is connected to the fourth end of the common-mode inductor; a grounding point is provided between the second Y5P capacitor and the second Y5V capacitor, the grounding point being used to connect to the ground wire; a connection point is provided between the second Y5P capacitor and the fourth end of the common-mode inductor.

[0013] In one embodiment of this utility model, the hybrid voltage divider network further includes: a first series structure and a second series structure; wherein, one end of the first series structure is connected to the ground wire, and the other end is the first output terminal of the hybrid voltage divider network; the first series structure includes: a first X7R capacitor, a first optocoupler pre-stage input resistor, and a second optocoupler pre-stage input resistor connected in sequence; one end of the second series structure is connected to the connection point, and the other end is the second output terminal of the hybrid voltage divider network; the second series structure includes: a second X7R capacitor, a third optocoupler pre-stage input resistor, and a fourth optocoupler pre-stage input resistor connected in sequence.

[0014] In one embodiment of this utility model, the optocoupler isolation module includes: a VCC power supply, a first resistor, a third X7R capacitor, an optocoupler, and an RC filter structure; wherein, the RC filter structure includes: a second resistor and a fourth X7R capacitor; the VCC power supply, the first resistor, and the third X7R capacitor are connected in sequence; the first end of the main side of the optocoupler is connected to the first output end of the hybrid voltage divider network, and the second end of the main side is connected to the second output end of the hybrid voltage divider network; the third end of the secondary side of the optocoupler, one end of the third X7R capacitor, and one end of the fourth X7R capacitor are connected together and grounded; the fourth end of the secondary side of the optocoupler is connected between the first resistor and the third X7R capacitor; one end of the second resistor and one end of the fourth X7R capacitor are connected together and connected to the control module, and the other end of the second resistor is connected between the first resistor and the third X7R capacitor.

[0015] In one embodiment of this utility model, a fuse is provided between the first Y5V capacitor and the live wire connection terminal.

[0016] In one embodiment of the present invention, the hybrid voltage divider network further has a third output terminal; the third output terminal is connected between the second Y5V capacitor C112 and the third terminal of the common mode inductor.

[0017] In one embodiment of this utility model, the control module is an MCU.

[0018] Similar to the above embodiments, this utility model also provides an AC charging pile, which is equipped with the AC charging pile grounding detection device as described above.

[0019] As described above, the AC charging pile grounding detection device and AC charging pile of this utility model have the following beneficial effects:

[0020] This invention solves the problem of abnormal voltage division caused by temperature drift and voltage fluctuation by using a hybrid voltage divider network and an optocoupler isolation module, thereby improving the accuracy of grounding detection. Attached Figure Description

[0021] Figure 1 The diagram shown is a schematic block diagram of the AC charging pile grounding detection device of this utility model;

[0022] Figure 2 The diagram shown is a structural schematic of the AC charging pile grounding detection device of this utility model. Detailed Implementation

[0023] The following specific embodiments illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification.

[0024] It should be understood that the structures, proportions, sizes, etc., depicted in the accompanying drawings of this specification are merely for illustrative purposes and to aid those skilled in the art in understanding and reading the content disclosed herein. They are not intended to limit the implementation conditions of this utility model and therefore have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to the size, without affecting the effects and objectives achieved by this utility model, should still fall within the scope of the technical content disclosed herein. Furthermore, the terms such as "upper," "lower," "left," "right," "middle," and "one" used in this specification are merely for clarity of description and are not intended to limit the scope of implementation of this utility model. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of implementation of this utility model.

[0025] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," "fixing," and "holding" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0026] Furthermore, as used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context indicates otherwise. It should be further understood that the terms “comprising,” “including,” indicate the presence of the stated feature, operation, element, component, item, kind, and / or group, but do not preclude the presence, occurrence, or addition of one or more other features, operations, elements, components, items, kinds, and / or groups. The terms “or” and “and / or” as used herein are interpreted as inclusive, or mean any one or any combination thereof. Thus, “A, B, or C” or “A, B, and / or C” means “any one of: A; B; C; A and B; A and C; B and C; A, B, and C.” Exceptions to this definition arise only when combinations of elements, functions, or operations are inherently mutually exclusive in some manner.

[0027] like Figure 1 as well as Figure 2 As shown, this utility model provides an AC charging pile grounding detection device.

[0028] The AC charging pile grounding detection device 1 in this embodiment includes:

[0029] A hybrid voltage divider network 11 based on Y5P and X7R, an optocoupler isolation module 12, and a control module 13;

[0030] The input end of the hybrid voltage divider network 11 is connected to the power grid to which the AC charging pile is connected, and the output end is connected to the optocoupler isolation module 12; the optocoupler isolation module is also connected to the control module 13.

[0031] The hybrid voltage divider network 11 is used to acquire the voltage detection signal; the optocoupler isolation module 12 is used to optocouple the voltage detection signal and input it to the control module 13.

[0032] In one embodiment, the power grid connected to the AC charging pile is a TT grid or a TN grid. The TT grid or TN grid is used to supply power to the AC charging pile. It should be understood that a TT grid refers to a power supply terminal having a point directly grounded, and the exposed conductive parts of the electrical device being connected to a grounding electrode that has no electrical connection to the power supply terminal grounding via a protective grounding wire. A TN grid refers to a power supply terminal having a point directly grounded, and the exposed conductive parts of the electrical device having a direct electrical connection to the power supply terminal grounding via a protective conductor.

[0033] In one embodiment, the control module is an MCU.

[0034] In one embodiment, such as Figure 2 As shown, the input terminals of the hybrid voltage divider network include: live wire input terminal L, ground wire input terminal PE, and neutral wire input terminal N; wherein, the live wire input terminal L is connected to the live wire (L line) of the power grid, the ground wire input terminal PE is connected to the ground wire (PE line) of the power grid, and the neutral wire input terminal N is connected to the neutral wire (N line) of the power grid.

[0035] In one embodiment, such as Figure 2 As shown, the hybrid voltage divider network includes: a first Y5P capacitor C108, a first Y5V capacitor C111, an X2 capacitor C110, and a common-mode inductor L5; wherein, one end of the first Y5P capacitor C108 is connected to the neutral wire input terminal, and the other end is connected to one end of the first Y5V capacitor C111; the other end of the first Y5V capacitor C111 is connected to the live wire input terminal; the ground wire input terminal is connected between the first Y5P capacitor C108 and the first Y5V capacitor C111; one end of the first Y5P capacitor C108 is also connected to one end of the X2 capacitor C110, and the other end of the first Y5V capacitor C111 is also connected to the other end of the X2 capacitor C110; one end of the X2 capacitor C110 is also connected to the first end of the common-mode inductor L5, and the other end of the X2 capacitor C110 is also connected to the second end of the common-mode inductor L5 through the first inductor L6.

[0036] In one embodiment, such as Figure 2 As shown, a fuse F1 is provided between the other end of the first Y5V capacitor C111 and the live wire connection terminal L. It should be understood that a fuse is a circuit protection device, the main function of which is to protect circuits and electrical equipment from damage caused by overcurrent.

[0037] In one embodiment, such as Figure 2 As shown, the hybrid voltage divider network further includes: a second Y5P capacitor C109 and a second Y5V capacitor C112; wherein, one end of the second Y5V capacitor C112 is connected to the third end of the common-mode inductor L5, the other end of the second Y5V capacitor C112 is connected to one end of the second Y5P capacitor C109, and the other end of the second Y5P capacitor C109 is connected to the fourth end of the common-mode inductor L5; a grounding point A is provided between the second Y5P capacitor C109 and the second Y5V capacitor C112, and the grounding point A is used to connect the ground wire (PE wire). A connection point B is provided between the second Y5P capacitor C109 and the fourth end of the common-mode inductor L5.

[0038] In one embodiment, such as Figure 2 As shown, the hybrid voltage divider network further includes: a first series structure and a second series structure; wherein, one end of the first series structure is connected to the ground line (PE line), and the other end is the first output terminal of the hybrid voltage divider network; the first series structure includes: a first X7R capacitor C118, a first optocoupler preamp input resistor R134, and a second optocoupler preamp input resistor R135 connected in sequence; one end of the second series structure is connected to connection point B, and the other end is the second output terminal of the hybrid voltage divider network; the second series structure includes: a second X7R capacitor C121, a third optocoupler preamp input resistor R137, and a fourth optocoupler preamp input resistor R136 connected in sequence.

[0039] Specifically, one end of the first X7R capacitor C118 is connected to the ground line (PE line). The other end of the input resistor R135 of the second optocoupler preamp is the first output terminal of the hybrid voltage divider network. One end of the second X7R capacitor C121 is connected to the connection point. The other end of the input resistor R136 of the fourth optocoupler preamp is the second output terminal of the hybrid voltage divider network. The voltage signals output from the first and second output terminals of the hybrid voltage divider network are voltage detection signals.

[0040] In one embodiment, such as Figure 2 As shown, the hybrid voltage divider network also has a third output terminal; one end of the second Y5V capacitor C112 is between the third terminal of the common-mode inductor L5 (located at point C).

[0041] It should be noted that the models of the first optocoupler preamplifier input resistor R134, the second optocoupler preamplifier input resistor R135, the third optocoupler preamplifier input resistor R137, and the fourth optocoupler preamplifier input resistor R136 can be selected according to actual needs, and this utility model does not limit them in this regard.

[0042] It should be noted that the safety capacitors (such as Y5V capacitors) used in existing grounding detection devices exhibit significant capacitance decay at extreme temperatures. For example, at -30℃, the capacitance of a traditional Y5V capacitor decays by up to 82%, leading to an imbalance in the voltage divider network and abnormal grounding detection results. Furthermore, at high temperatures of 85℃, capacitor aging accelerates, further exacerbating capacitance drift (e.g., capacitance decay reaches 20%). Y5P capacitors, within a temperature range of -55℃ to 125℃, exhibit capacitance fluctuations of ≤±15% (a significant improvement compared to the ±82% of Y5V capacitors, and possess excellent low-temperature stability). X7R capacitors have a temperature coefficient of ≤±15% (-55℃ to 125℃), and their capacitance stability is superior to conventional capacitors. It should also be noted that the hybrid voltage divider network of this invention utilizes the low-frequency response characteristics of capacitors and the high-precision voltage dividing capability of resistors to form a dynamic compensation mechanism.

[0043] In one specific embodiment, the output stability of the voltage divider network is improved by 85% at -30°C (compared to only 32% in existing testing devices); and the capacitance fluctuation is no more than ±8% at 85°C (compared to ±60% in existing testing devices).

[0044] To better illustrate the hybrid voltage divider network, a specific embodiment is provided below:

[0045] Example 1: A hybrid voltage divider network.

[0046] The capacitance of both the first Y5P capacitor and the second Y5P capacitor is 220pF. The capacitance of both the first Y5V capacitor and the second Y5V capacitor is 4.7nF. The capacitance of both the first X7R capacitor and the second X7R capacitor is 10nF.

[0047] In one embodiment, the optocoupler isolation module includes: a VCC power supply, a first resistor R133, a third X7R capacitor C119, an optocoupler U16, and an RC filter structure; wherein, the RC filter structure includes: a second resistor R167 and a fourth X7R capacitor C120; the VCC power supply, the first resistor R133, and the third X7R capacitor C119 are connected in sequence; the first end of the main side of the optocoupler is connected to the first output end of the hybrid voltage divider network, and the second end of the main side is connected to the second output end of the hybrid voltage divider network; the third end of the secondary side of the optocoupler, one end of the third X7R capacitor C119, and one end of the fourth X7R capacitor C120 are connected and grounded; the fourth end of the secondary side of the optocoupler is connected between the first resistor R133 and the third X7R capacitor C119; one end of the second resistor R167 and one end of the fourth X7R capacitor C120 are connected and connected to the control module, and the other end of the second resistor R167 is connected between the first resistor R133 and the third X7R capacitor C119.

[0048] It should be noted that the optocoupler isolation module increases the insulation resistance, power frequency withstand voltage, and pulse withstand voltage capabilities between strong and weak electrical signals, while blocking the interference of neutral point offset on the detection signal. The RC filter structure suppresses high-frequency noise. The main side of the optocoupler refers to the circuit section containing the light-emitting element, and the secondary side refers to the circuit section containing the photosensitive element.

[0049] In one embodiment, the resistance values ​​of the first optocoupler preamplifier input resistor R134, the second optocoupler preamplifier input resistor R135, the third optocoupler preamplifier input resistor R137, the fourth optocoupler preamplifier input resistor R136, and the first resistor R133 are related to the parameters of optocoupler U16. When the parameters of the optocoupler change, the resistance values ​​of the first optocoupler preamplifier input resistor R134, the second optocoupler preamplifier input resistor R135, the third optocoupler preamplifier input resistor R137, the fourth optocoupler preamplifier input resistor R136, and the first resistor R133 will also be adjusted accordingly. The parameters of optocoupler U16 include: CTR (Current Transfer Ratio), on-state voltage drop, and on-state current. It should be understood that the resistance values ​​of the first optocoupler preamp input resistor R134, the second optocoupler preamp input resistor R135, the third optocoupler preamp input resistor R137, the fourth optocoupler preamp input resistor R136, and the first resistor R133 can be obtained through experimental debugging and combined with the whole pile power frequency withstand voltage test.

[0050] To better illustrate the optocoupler isolation module, a specific embodiment is provided below:

[0051] Example 2: An optocoupler isolation module.

[0052] The CTR of the optocoupler is 50%-140%, and the forward voltage drop V of the optocoupler's front-end is... f The voltage is 0.8-1.1V, and the conduction current I is... f The current is 5mA, and the VCC power supply voltage is 3.3V. The first resistor R133 has a resistance of 240KΩ, the first optocoupler preamp input resistor R134, the second optocoupler preamp input resistor R135, the third optocoupler preamp input resistor R137, and the fourth optocoupler preamp input resistor R136 all have a resistance of 51KΩ, the second resistor R167 has a resistance of 1KΩ, and the fourth X7R capacitor C120 has a capacitance of 0.1μF.

[0053] Electrical isolation characteristics: insulation resistance ≥7MΩ, power frequency withstand voltage AC 2860V (>1 minute), pulse withstand voltage 6000V.

[0054] It should be noted that in TT / TN systems, when the three phases are unbalanced or the load is asymmetrical, the neutral point offset can reach 30Vac. This voltage difference is directly superimposed on the detection signal, causing the system to misjudge it as a ground fault and trigger unnecessary alarms. For example, when the neutral point offset is 30Vac, the false alarm rate is 40%. This invention uses optocoupler isolation technology to reduce the false alarm rate to zero. When temperature drift, voltage fluctuation, and neutral point offset work together, the detection circuit's decision logic conflicts. For example, when low temperature causes capacitance decay and voltage fluctuations are superimposed, the system misjudges it as a PE disconnection, and the neutral point offset further exacerbates the risk of false alarms, creating a vicious cycle. In scenarios where multiple factors are superimposed, the false judgment rate can be as high as 80%. However, the detection device of this invention reduces the false judgment rate to 0%. The existing ground fault detection circuit has a PE disconnection detection rate of 32%, while the detection device of this invention has a PE disconnection detection rate of 100%. It can operate for 1000 hours at 85℃+85%RH with a capacitance fluctuation of ≤±8% (compared to ±60% for traditional solutions), and can run continuously for 2000 hours without failure.

[0055] In one embodiment, the control module performs a grounding detection operation based on a preset voltage detection threshold and the voltage value corresponding to the received optocoupler-isolated voltage detection signal, thereby obtaining a corresponding grounding detection result. Specifically, if the preset voltage detection threshold is greater than the voltage value corresponding to the optocoupler-isolated voltage detection signal, a grounding detection result indicating a PE fault is obtained; if the preset voltage detection threshold is not greater than the voltage value corresponding to the optocoupler-isolated voltage detection signal, a grounding detection result indicating no PE fault is obtained. It should be noted that the voltage value obtained from the voltage detection signal and the threshold determination both employ existing methods, and this invention does not involve any algorithm improvement. The voltage detection threshold can be set according to actual needs, and this invention does not limit it in this regard.

[0056] This utility model also provides an AC charging pile, which is equipped with the AC charging pile grounding detection device as described above. It should be noted that the AC charging pile grounding detection device has been described in the above embodiments and will not be repeated here.

[0057] In summary, this utility model provides an AC charging pile grounding detection device and an AC charging pile. The AC charging pile grounding detection device includes a hybrid voltage divider network based on Y5P and X7R, an optocoupler isolation module, and a control module. The input end of the hybrid voltage divider network is connected to the power grid to which the AC charging pile is connected, and the output end is connected to the optocoupler isolation module. The optocoupler isolation module is also connected to the control module. The hybrid voltage divider network is used to acquire voltage detection signals; the optocoupler isolation module is used to optically isolate the voltage detection signals and input them to the control module. This utility model solves the problem of voltage division anomalies caused by temperature drift and voltage fluctuations through the hybrid voltage divider network and optocoupler isolation module, improving the accuracy of grounding detection. Therefore, this utility model effectively overcomes the various shortcomings of the prior art and has high industrial application value.

[0058] The above embodiments are merely illustrative of the principles and effects of this utility model and are not intended to limit the scope of this utility model. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this utility model. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this utility model should still be covered by the claims of this utility model.

Claims

1. An alternating current charging pile ground detection device, characterized in that, include: Hybrid voltage divider network, optocoupler isolation module and control module based on Y5P and X7R; The input end of the hybrid voltage divider network is connected to the power grid to which the AC charging pile is connected, and the output end is connected to the optocoupler isolation module; the optocoupler isolation module is also connected to the control module. The hybrid voltage divider network is used to acquire the voltage detection signal; the optocoupler isolation module is used to optically isolate the voltage detection signal and input it to the control module.

2. The AC charging pile ground detection device according to claim 1, characterized in that, The input terminals of the hybrid voltage divider network include: a live wire input terminal, a ground wire input terminal, and a neutral wire input terminal; wherein, the live wire input terminal is connected to the live wire of the power grid, the ground wire input terminal is connected to the ground wire of the power grid, and the neutral wire input terminal is connected to the neutral wire of the power grid.

3. The AC charging pile ground detection device according to claim 2, characterized in that, The hybrid voltage divider network includes: a first Y5P capacitor, a first Y5V capacitor, an X2 capacitor, and a common-mode inductor; Specifically, one end of the first Y5P capacitor is connected to the neutral wire input terminal, and the other end is connected to one end of the first Y5V capacitor; the other end of the first Y5V capacitor is connected to the live wire input terminal; the ground wire input terminal is connected between the first Y5P capacitor and the first Y5V capacitor; one end of the first Y5P capacitor is also connected to one end of the X2 capacitor, and the other end of the first Y5V capacitor is also connected to the other end of the X2 capacitor; one end of the X2 capacitor is also connected to the first end of the common mode inductor, and the other end of the X2 capacitor is also connected to the second end of the common mode inductor through the first inductor.

4. The AC charging pile ground detection device according to claim 3, characterized in that, The hybrid voltage divider network also includes: a second Y5P capacitor and a second Y5V capacitor; One end of the second Y5V capacitor is connected to the third end of the common-mode inductor, the other end of the second Y5V capacitor is connected to one end of the second Y5P capacitor, and the other end of the second Y5P capacitor is connected to the fourth end of the common-mode inductor; a grounding point is provided between the second Y5P capacitor and the second Y5V capacitor, and the grounding point is used to connect to the ground wire; a connection point is provided between the second Y5P capacitor and the fourth end of the common-mode inductor.

5. The AC charging pile ground detection device according to claim 4, characterized in that, The hybrid voltage divider network further includes: a first series structure and a second series structure; In this configuration, one end of the first series structure is connected to the ground wire, and the other end is the first output terminal of the hybrid voltage divider network. The first series structure includes a first X7R capacitor, a first optocoupler preamp input resistor, and a second optocoupler preamp input resistor connected in sequence. One end of the second series structure is connected to the connection point, and the other end is the second output terminal of the hybrid voltage divider network. The second series structure includes a second X7R capacitor, a third optocoupler preamp input resistor, and a fourth optocoupler preamp input resistor connected in sequence.

6. The AC charging pile ground detection device according to claim 5, characterized in that, The optocoupler isolation module includes: VCC power supply, first resistor, third X7R capacitor, optocoupler, and RC filter structure; The RC filter structure includes: a second resistor and a fourth X7R capacitor; the VCC power supply, the first resistor, and the third X7R capacitor are connected in sequence; the first end of the main side of the optocoupler is connected to the first output end of the hybrid voltage divider network, and the second end of the main side is connected to the second output end of the hybrid voltage divider network; the third end of the secondary side of the optocoupler, one end of the third X7R capacitor, and one end of the fourth X7R capacitor are connected and grounded; the fourth end of the secondary side of the optocoupler is connected between the first resistor and the third X7R capacitor; one end of the second resistor and one end of the fourth X7R capacitor are connected and connected to the control module, and the other end of the second resistor is connected between the first resistor and the third X7R capacitor.

7. The AC charging pile ground detection device according to claim 3, characterized in that, A fuse is provided between the first Y5V capacitor and the live wire connection terminal.

8. The AC charging pile ground detection device according to claim 4, characterized in that, The hybrid voltage divider network also has a third output terminal; the third output terminal is connected between the second Y5V capacitor C112 and the third terminal of the common mode inductor.

9. The AC charging pile ground detection device according to claim 1, characterized in that, The control module is an MCU.

10. An AC charging pile, characterized in that, The AC charging pile is equipped with an AC charging pile grounding detection device as described in any one of claims 1 to 9.

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