Alternating current charging pile and short circuit detection circuit thereof

Abstract

The utility model relates to an AC charging pile and a short circuit detection circuit thereof. The short circuit detection circuit comprises a power supply input module which is connected with a zero line-live line detection module and a live line-live line detection module and is used for transmitting accessed input voltage to the zero line-live line detection module and the live line-live line detection module; the null line-live wire detection module is connected with a null line and three live wires at the output end of the alternating current charging pile, and generates a first detection signal when the null line is in short circuit with any one live wire; the live wire-live wire detection module is connected with three live wires at the output end of the alternating current charging pile and generates a second detection signal when any two live wires are short-circuited; and the signal output module is connected with the zero line-live wire detection module and the live wire-live wire detection module, and outputs a short circuit signal based on the received first detection signal or the second detection signal. According to the utility model, comprehensive short-circuit detection can be carried out on the live wire and the zero wire at the output end of the AC charging pile, and the charging safety coefficient is improved.

Description

Technical Field

[0001] This utility model relates to the field of AC charging piles, and in particular to an AC charging pile and its short-circuit detection circuit. Background Technology

[0002] AC charging stations are used to charge electric vehicles. If the output terminal of an AC charging station is short-circuited, the station's initiation of charging may burn out, damaging the charging electric vehicle and potentially causing a serious fire or other safety accident. To provide users with a better charging experience and safety, output short-circuit detection is necessary before the AC charging station starts charging. Therefore, there is an urgent need to design an output short-circuit detection scheme that features simplified control logic, a high safety factor, and low cost. Utility Model Content

[0003] The technical problem to be solved by this utility model is to provide an AC charging pile and its short-circuit detection circuit.

[0004] The technical solution adopted by this utility model to solve its technical problem is as follows: a short-circuit detection circuit for an AC charging pile is provided, comprising: a power input module, a neutral-live wire detection module, a live wire-live wire detection module, and a signal output module; the power input module is connected to the neutral-live wire detection module and the live wire-live wire detection module, and is used to supply the input voltage to the neutral-live wire detection module and the live wire-live wire detection module; the neutral-live wire detection module is connected to the neutral wire and three live wires at the output end of the AC charging pile, and generates a first detection signal when the neutral wire is short-circuited with any one of the live wires; the live wire-live wire detection module is connected to the three live wires at the output end of the AC charging pile, and generates a second detection signal when any two live wires are short-circuited; the signal output module is connected to the neutral-live wire detection module and the live wire-live wire detection module, and outputs a short-circuit signal based on the received first detection signal or second detection signal.

[0005] Furthermore, the second detection signal includes a first detection sub-signal and a second detection sub-signal. The live wire-to-live wire detection module includes a live wire-to-live wire first detection sub-module and a live wire-to-live wire second detection sub-module. The live wire-to-live wire first detection sub-module connects three live wires and generates the first detection sub-signal when a short circuit occurs between the first and second live wires and / or between the first and third live wires. The live wire-to-live wire second detection sub-module connects the second and third live wires and generates the second detection sub-signal when a short circuit occurs between the second and third live wires.

[0006] Furthermore, the neutral-live wire detection module includes resistors R2, R3, R4, R8, R9, and R10, and rectifier diodes D5, D6, and D7. The first ends of resistors R2, R3, and R4 are all connected to the power input module and the neutral wire. The second end of resistor R2 is connected to the first live wire and the positive terminal of rectifier diode D5, and the negative terminal of rectifier diode D5 is connected to the signal output module through resistor R8. The second end of resistor R3 is connected to the second live wire and the positive terminal of rectifier diode D6, and the negative terminal of rectifier diode D6 is connected to the signal output module through resistor R9. The second end of resistor R4 is connected to the third live wire and the positive terminal of rectifier diode D7, and the negative terminal of rectifier diode D7 is connected to the signal output module through resistor R10.

[0007] The live wire-live wire first detection submodule includes resistors R5, R6, R11, R12, rectifier diode D8, and rectifier diode D9. The first ends of resistors R5 and R6 are both connected to the power input module and the first live wire. The second end of resistor R5 is connected to the second live wire and the positive terminal of rectifier diode D8, and the negative terminal of rectifier diode D8 is connected to the signal output module through resistor R11. The second end of resistor R6 is connected to the third live wire and the positive terminal of rectifier diode D9, and the negative terminal of rectifier diode D9 is connected to the signal output module through resistor R12.

[0008] The live wire-live wire second detection submodule includes resistor R7, resistor R13 and rectifier diode D10; the first end of resistor R7 is connected to the power input module and the second live wire, the second end of resistor R7 is connected to the third live wire and the positive terminal of rectifier diode D10, and the negative terminal of rectifier diode D10 is connected to the signal output module through resistor R13.

[0009] Furthermore, the short-circuit detection circuit also includes a switching unit and an anti-interference unit; the switching unit is connected to the power input module, and is connected to the neutral-live wire detection module, the live wire-live wire first detection submodule, and the live wire-live wire second detection submodule through the anti-interference unit.

[0010] Furthermore, the switching unit includes switches K2, K3, and K4, and the anti-interference unit includes rectifier diodes D2, D3, and D4. The positive terminal of rectifier diode D2 is connected to the power input module through switch K2, and the negative terminal is connected to the neutral-live wire detection module. The positive terminal of rectifier diode D3 is connected to the power input module through switch K3, and the negative terminal is connected to the live-live wire first detection submodule. The positive terminal of rectifier diode D4 is connected to the power input module through switch K4, and the negative terminal is connected to the live-live wire second detection submodule.

[0011] Further, the short-circuit signal includes a first short-circuit signal, a second short-circuit signal, and a third short-circuit signal; the signal output module includes optocoupler U1, optocoupler U2, and optocoupler U3; pin 1 of optocoupler U1 is connected to the neutral-live wire detection module, pin 2 is connected to analog ground, pin 3 is connected to power ground, and pin 4 outputs the first short-circuit signal; pin 1 of optocoupler U2 is connected to the live wire-live wire first detection submodule, pin 2 is connected to analog ground, pin 3 is connected to power ground, and pin 4 outputs the second short-circuit signal; pin 1 of optocoupler U3 is connected to the live wire-live wire second detection submodule, pin 2 is connected to analog ground, pin 3 is connected to power ground, and pin 4 outputs the third short-circuit signal.

[0012] Furthermore, the short-circuit detection circuit also includes a control module; the control module is connected to the signal output module and the output terminal of the AC charging pile, outputs a fault signal based on the received short-circuit signal, and disconnects the output terminal of the AC charging pile.

[0013] Furthermore, the power input module includes a resistor R1 and a rectifier diode D1; the positive terminal of the rectifier diode D1 is connected to an external isolation power supply to receive the input voltage; the negative terminal of the rectifier diode D1 is connected to the neutral-live wire detection module and the live wire-live wire detection module through the resistor R1.

[0014] Furthermore, the short-circuit detection circuit also includes a detection switch module; the neutral-live wire detection module and the live wire-live wire detection module are connected to the output terminal of the AC charging pile through the detection switch module.

[0015] An AC charging pile is also provided, including a short-circuit detection circuit for the AC charging pile described in any of the above claims.

[0016] The present invention has the following advantages: the neutral-live wire detection module can generate a first detection signal when the neutral wire is short-circuited with any one of the live wires, and the live wire-live wire detection module can generate a second detection signal when any two live wires are short-circuited. After receiving the first or second detection signal, the signal output module outputs a short-circuit signal, thereby enabling comprehensive short-circuit detection of the live and neutral wires at the output of the AC charging pile and improving the safety factor of charging. Attached Figure Description

[0017] The present invention will be further described below with reference to the accompanying drawings and embodiments. In the accompanying drawings:

[0018] Figure 1 This is a structural block diagram of an embodiment of the short-circuit detection circuit for an AC charging pile of this utility model;

[0019] Figure 2 This is the circuit diagram of the detection switch module of this utility model;

[0020] Figure 3 This is a circuit diagram of an embodiment of the short-circuit detection circuit for an AC charging pile according to this utility model. Detailed Implementation

[0021] To provide a clearer understanding of the technical features, objectives, and effects of this utility model, the specific embodiments of this utility model are now described in detail with reference to the accompanying drawings. In the following description, it should be understood that the terms "first," "second," etc., are used only for the convenience of describing this technical solution and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, features defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0022] like Figure 1 As shown, in one embodiment of the short-circuit detection circuit of the AC charging pile of this utility model, it includes: a power input module 10, a neutral-to-live wire detection module 20, a live wire-to-live wire detection module 30, and a signal output module 40.

[0023] The power input module 10 is connected to the neutral-live wire detection module 20 and the live wire-live wire detection module 30, and is used to supply the input voltage to the neutral-live wire detection module 20 and the live wire-live wire detection module 30. The neutral-live wire detection module 20 is connected to the neutral wire and three live wires at the output terminal of the AC charging pile, and generates a first detection signal when the neutral wire is short-circuited with any one of the live wires. The live wire-live wire detection module 30 is connected to the three live wires at the output terminal of the AC charging pile, and generates a second detection signal when any two live wires are short-circuited. The signal output module 40 is connected to the neutral-live wire detection module 20 and the live wire-live wire detection module 30, and outputs a short-circuit signal based on the received first detection signal or second detection signal.

[0024] Specifically, the power input module 10 is connected to an external DC isolated power supply VDD and supplies power to the neutral-live wire detection module 20 and the live wire-live wire detection module 30. The AC charging pile outputs three-phase AC power, including a neutral wire, phase A live wire, phase B live wire, and phase C live wire. The neutral-live wire detection module 20 is used to detect short circuits between the neutral and live wires. A first detection signal indicates a short circuit between the neutral and live wires. The live wire-live wire detection module 30 is used to detect short circuits between live wires. A second detection signal indicates a short circuit between live wires. After receiving the first or second detection signal, the signal output module 40 outputs a short circuit signal. This short circuit signal indicates a short circuit fault at the output of the AC charging pile. This embodiment can perform comprehensive short circuit detection on the live and neutral wires at the output of the AC charging pile, improving the safety of charging.

[0025] In one embodiment, the second detection signal includes a first detection sub-signal and a second detection sub-signal. The live wire-to-live wire detection module 30 includes a live wire-to-live wire first detection sub-module and a live wire-to-live wire second detection sub-module. The live wire-to-live wire first detection sub-module connects three live wires and generates a first detection sub-signal when a short circuit occurs between the first and second live wires and / or between the first and third live wires. The live wire-to-live wire second detection sub-module connects the second and third live wires and generates a second detection sub-signal when a short circuit occurs between the second and third live wires.

[0026] Specifically, the live wire-to-live wire first detection submodule is used to detect short circuits between the first live wire and the other two live wires. A first detection sub-signal indicates that a short circuit has occurred between the first live wire and the other two live wires. The live wire-to-live wire second detection submodule is used to detect short circuits between the second live wire and the third live wire. A second detection sub-signal indicates that a short circuit has occurred between the second live wire and the third live wire. The signal output module 40 outputs a short circuit signal after receiving either the first or second detection sub-signal. In this embodiment, the first live wire is phase A, the second live wire is phase B, and the third live wire is phase C. In other embodiments, the order of the three-phase live wires can be adjusted according to actual needs.

[0027] In one embodiment, the short-circuit detection circuit further includes a control module. The control module is connected to the signal output module 40 and the AC charging pile output terminal, outputs a fault signal based on the received short-circuit signal, and disconnects the AC charging pile output terminal.

[0028] In this embodiment, the control module includes an MCU. The control module receives a short-circuit signal from the signal output module 40, which directly determines that a short circuit has occurred at the charging pile's output terminal, and then outputs a charging pile fault signal. Furthermore, the control module disables the AC charging pile from charging the vehicle by disconnecting the switch between the AC charging pile's output terminal and the electric vehicle, or by adjusting the output voltage of the output terminal to 0. If no short-circuit signal is received, normal charging is allowed.

[0029] In one embodiment, the short-circuit detection circuit further includes a switching unit and an anti-interference unit. The switching unit is connected to the power input module 10, and is connected to the neutral-live wire detection module 20, the live wire-live wire first detection submodule, and the live wire-live wire second detection submodule through the anti-interference unit.

[0030] The switching unit can operate in either manual or automatic mode. In manual mode, the switching unit is manually controlled by the user to close or open. In automatic mode, the switching unit is connected to the control module, which controls its closure or opening. The switching unit connects the power input module 10 to a specific detection module or sub-module to activate the corresponding detection function. Additionally, an anti-interference unit prevents the AC voltage at the AC charging pile output from interfering with the DC voltage of the power input module 10.

[0031] In one embodiment, the short-circuit detection circuit further includes a detection switch module K1. The neutral-to-live wire detection module 20 and the live wire-to-live wire detection module 30 are connected to the output terminal of the AC charging pile via the detection switch module.

[0032] like Figure 2 As shown, the detection switch module K1 includes four channels. The input of the first channel is connected to the neutral wire Nout of the AC charging pile output, and the output of the first channel is a signal Nout_S isolated by the detection switch module. The input of the second channel is connected to the A-phase live wire Aout of the AC charging pile output, and the output of the second channel is a signal Aout_S isolated by the detection switch module. The input of the third channel is connected to the B-phase live wire Bout of the AC charging pile output, and the output of the third channel is a signal Bout_S isolated by the detection switch module. The input of the fourth channel is connected to the C-phase live wire Cout of the AC charging pile output, and the output of the third channel is a signal Cout_S isolated by the detection switch module.

[0033] The neutral-to-live wire detection module 20 connects to the output terminals of four channels, receiving signals such as Nout_S, Aout_S, Bout_S, and Cout_S. The live wire-to-live wire detection module 30 connects to the output terminals of the second, third, and fourth channels, receiving signals such as Aout_S, Bout_S, and Cout_S. The detection switch module closes before charging, connecting the charging pile's output terminal to the short-circuit detection circuit for output short-circuit detection. The detection switch module opens when not in the detection state, isolating the charging pile's output terminal from the short-circuit detection circuit, ensuring the short-circuit detection circuit is not affected by the high-voltage circuit at the charging pile's output terminal and thus operates normally.

[0034] refer to Figure 3 The following describes a short-circuit detection circuit using a specific embodiment.

[0035] In this embodiment, the power input module 10 includes a resistor R1 and a rectifier diode D1. The anode of the rectifier diode D1 is connected to an external isolated power supply to receive the input voltage. The cathode of the rectifier diode D1 is connected to the neutral-live wire detection module 20 and the live-live wire detection module 30 through the resistor R1. The input voltage is provided by an external DC isolated power supply VDD, and 12V is recommended. The resistor R1 is used for current limiting.

[0036] In this embodiment, the switching unit includes switches K2, K3, and K4, and the anti-interference unit includes rectifier diodes D2, D3, and D4. The positive terminal of rectifier diode D2 is connected to the power input module 10 via switch K2, and the negative terminal is connected to the neutral-live wire detection module 20. The positive terminal of rectifier diode D3 is connected to the power input module 10 via switch K3, and the negative terminal is connected to the live-live wire first detection submodule. The positive terminal of rectifier diode D4 is connected to the power input module 10 via switch K4, and the negative terminal is connected to the live-live wire second detection submodule. Switches K2, K3, and K4 can be optocouplers or relays for isolation.

[0037] In this embodiment, the neutral-live wire detection module 20 includes resistors R2, R3, R4, R8, R9, R10, rectifier diodes D5, D6, and D7. The first ends of resistors R2, R3, and R4 are all connected to the power input module 10 and the neutral wire. The second end of resistor R2 is connected to the first live wire and the positive terminal of rectifier diode D5, and the negative terminal of rectifier diode D5 is connected to the signal output module 40 through resistor R8. The second end of resistor R3 is connected to the second live wire and the positive terminal of rectifier diode D6, and the negative terminal of rectifier diode D6 is connected to the signal output module 40 through resistor R9. The second end of resistor R4 is connected to the third live wire and the positive terminal of rectifier diode D7, and the negative terminal of rectifier diode D7 is connected to the signal output module 40 through resistor R10. Among them, resistors R2, R3, and R4 are high-value resistors, and their resistance values ​​should meet the following requirement: when no short circuit occurs, the current output from the branch to the signal output module 40 does not exceed 1mA.

[0038] In this embodiment, the live wire-to-live wire first detection submodule includes resistors R5, R6, R11, R12, rectifier diodes D8 and D9. The first ends of resistors R5 and R6 are connected to the power input module 10 and the first live wire. The second end of resistor R5 is connected to the second live wire and the positive terminal of rectifier diode D8, and the negative terminal of rectifier diode D8 is connected to the signal output module 40 through resistor R11. The second end of resistor R6 is connected to the third live wire and the positive terminal of rectifier diode D9, and the negative terminal of rectifier diode D9 is connected to the signal output module 40 through resistor R12. Resistors R5 and R6 are high-value resistors, and their resistance values ​​should satisfy the following condition: when no short circuit occurs, the current output from their respective branches to the signal output module 40 does not exceed 1mA.

[0039] In this embodiment, the live wire-live wire second detection submodule includes resistor R7, resistor R13, and rectifier diode D10. The first end of resistor R7 is connected to the power input module 10 and the second live wire, and the second end of resistor R7 is connected to the third live wire and the positive terminal of rectifier diode D10. The negative terminal of rectifier diode D10 is connected to signal output module 40 through resistor R13. Resistor R7 is a high-value resistor, and its resistance value should satisfy the following condition: when no short circuit occurs, the current output from its branch to signal output module 40 does not exceed 1mA.

[0040] In this embodiment, the short-circuit signal includes a first short-circuit signal, a second short-circuit signal, and a third short-circuit signal. The signal output module 40 includes optocouplers U1, U2, and U3. Pin 1 of optocoupler U1 is connected to the neutral-live wire detection module 20, pin 2 is connected to analog ground AGND, pin 3 is connected to power ground GND, and pin 4 outputs the first short-circuit signal. Pin 1 of optocoupler U2 is connected to the live wire-live wire first detection submodule, pin 2 is connected to analog ground AGND, pin 3 is connected to power ground GND, and pin 4 outputs the second short-circuit signal. Pin 1 of optocoupler U3 is connected to the live wire-live wire second detection submodule, pin 2 is connected to analog ground AGND, pin 3 is connected to power ground GND, and pin 4 outputs the third short-circuit signal.

[0041] The specific working principle of the short-circuit detection circuit in this embodiment is as follows:

[0042] After the charging gun of the AC charging pile to be tested is connected to the electric vehicle, the detection switch module K1 closes.

[0043] When switch K2 is closed and switches K3 and K4 are open, a short circuit is detected between the neutral and live wires. Taking the neutral wire and phase A live wire as an example: if there is no short circuit between Nout_S and Aout_S, the current output of the branch containing resistor R2, rectifier diode D5, and resistor R8 will not exceed 1mA, and optocoupler U1 will not output a short circuit signal. If a short circuit occurs between Nout_S and Aout_S, resistor R2 is short-circuited, the current output of its branch increases, causing the LED in optocoupler U1 to operate, and simultaneously turning on the photosensitive element in optocoupler U1, causing optocoupler U1 to output a short circuit signal. The principle is the same when the neutral wire and phase B live wire, or the neutral wire and phase C live wire, occur, and will not be repeated here.

[0044] When switch K3 is closed and switches K2 and K4 are open, it detects whether there is a short circuit between phase A and the other two live wires. Taking phase A and phase B as an example: if there is no short circuit between Bout_S and Aout_S, the current output of the branch containing resistor R5, rectifier diode D8, and resistor R11 will not exceed 1mA, and optocoupler U2 will not output a short circuit signal. If a short circuit occurs between Bout_S and Aout_S, resistor R5 is short-circuited, the current output of the branch increases, causing the LED in optocoupler U2 to work, and simultaneously turning on the photosensitive element in optocoupler U2, causing optocoupler U2 to output a short circuit signal. The principle is the same when phase A and phase C are short-circuited, and will not be repeated here.

[0045] When switch K4 is closed and switches K2 and K3 are open, a short circuit is detected between phase B and phase C. If there is no short circuit between Bout_S and Cout_S, the current output of the branch containing resistor R7, rectifier diode D10, and resistor R13 will not exceed 1mA, and optocoupler U3 will not output a short circuit signal. If a short circuit occurs between Bout_S and Cout_S, resistor R7 is short-circuited, the current output of its branch increases, causing the LED in optocoupler U3 to operate and simultaneously turning on the photosensitive element in optocoupler U3, resulting in optocoupler U3 outputting a short circuit signal.

[0046] If the control module receives a short-circuit signal from any of the optocoupler outputs, it will prohibit the AC charging pile from charging external devices. If no short-circuit signal is received, the charging pile will be allowed to charge normally, and the detection switch module K1 will be disconnected. The circuit control logic of this embodiment is simple, low-cost, and highly reliable.

[0047] In another embodiment, if it is necessary to determine the two lines where a short circuit occurs, the signal output module 40 can use six optocouplers, with each branch connected to one optocoupler. The control module can then pinpoint the two lines where a short circuit occurs based on the source of the short circuit signal.

[0048] This utility model also provides an AC charging pile, including the short-circuit detection circuit of the AC charging pile disclosed in any of the above embodiments. By adopting this short-circuit detection circuit, the AC charging pile can perform short-circuit detection before charging, prohibit charging when a short circuit occurs, and allow charging when no short circuit occurs, providing users with a good charging experience and safety guarantee.

[0049] It is understood that the above embodiments only illustrate preferred embodiments of the present utility model, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the present utility model patent. It should be noted that for those skilled in the art, the above technical features can be freely combined, and several modifications and improvements can be made without departing from the concept of the present utility model, all of which fall within the protection scope of the present utility model. Therefore, all equivalent transformations and modifications made within the scope of the claims of the present utility model should fall within the coverage of the claims of the present utility model.

Claims

1. A short-circuit detection circuit for an AC charging pile, characterized in that, include: Power input module, neutral-live wire detection module, live wire-live wire detection module, and signal output module; The power input module is connected to the neutral-live wire detection module and the live wire-live wire detection module, and is used to supply the input voltage to the neutral-live wire detection module and the live wire-live wire detection module; The neutral-live wire detection module is connected to the neutral wire and three live wires at the output of the AC charging pile, and generates a first detection signal when the neutral wire is short-circuited with any one of the live wires. The live wire-live wire detection module is connected to the three live wires at the output end of the AC charging pile, and generates a second detection signal when any two live wires are short-circuited. The signal output module is connected to the neutral-live wire detection module and the live wire-live wire detection module, and outputs a short-circuit signal based on the received first detection signal or second detection signal.

2. The short-circuit detection circuit for the AC charging pile according to claim 1, characterized in that, The second detection signal includes a first detection sub-signal and a second detection sub-signal, and the live wire-to-live wire detection module includes a live wire-to-live wire first detection sub-module and a live wire-to-live wire second detection sub-module; The live wire-live wire first detection submodule connects three live wires and generates the first detection sub-signal when the first live wire and the second live wire are short-circuited and / or the first live wire and the third live wire are short-circuited. The live wire-live wire second detection submodule connects the second live wire and the third live wire, and generates the second detection sub-signal when a short circuit occurs between the second live wire and the third live wire.

3. The short-circuit detection circuit for an AC charging pile according to claim 2, characterized in that, The neutral-live wire detection module includes resistors R2, R3, R4, R8, R9, and R10, and rectifier diodes D5, D6, and D7. The first ends of resistors R2, R3, and R4 are all connected to the power input module and the neutral wire. The second end of resistor R2 is connected to the first live wire and the positive terminal of rectifier diode D5, and the negative terminal of rectifier diode D5 is connected to the signal output module through resistor R8. The second end of resistor R3 is connected to the second live wire and the positive terminal of rectifier diode D6, and the negative terminal of rectifier diode D6 is connected to the signal output module through resistor R9. The second end of resistor R4 is connected to the third live wire and the positive terminal of rectifier diode D7, and the negative terminal of rectifier diode D7 is connected to the signal output module through resistor R10. The live wire-live wire first detection submodule includes resistors R5, R6, R11, R12, rectifier diode D8, and rectifier diode D9. The first ends of resistors R5 and R6 are both connected to the power input module and the first live wire. The second end of resistor R5 is connected to the second live wire and the positive terminal of rectifier diode D8, and the negative terminal of rectifier diode D8 is connected to the signal output module through resistor R11. The second end of resistor R6 is connected to the third live wire and the positive terminal of rectifier diode D9, and the negative terminal of rectifier diode D9 is connected to the signal output module through resistor R12. The live wire-live wire second detection submodule includes resistor R7, resistor R13 and rectifier diode D10; the first end of resistor R7 is connected to the power input module and the second live wire, the second end of resistor R7 is connected to the third live wire and the positive terminal of rectifier diode D10, and the negative terminal of rectifier diode D10 is connected to the signal output module through resistor R13.

4. The short-circuit detection circuit for the AC charging pile according to claim 2, characterized in that, The short-circuit detection circuit also includes a switching unit and an anti-interference unit; The switching unit is connected to the power input module, and is connected to the neutral-live wire detection module, the live wire-live wire first detection submodule, and the live wire-live wire second detection submodule through the anti-interference unit.

5. The short-circuit detection circuit for an AC charging pile according to claim 4, characterized in that, The switching unit includes switches K2, K3 and K4, and the anti-interference unit includes rectifier diodes D2, D3 and D4. The positive terminal of the rectifier diode D2 is connected to the power input module through the switch K2, and the negative terminal is connected to the neutral-live wire detection module. The positive terminal of the rectifier diode D3 is connected to the power input module through the switch K3, and the negative terminal is connected to the live wire-to-live wire first detection submodule. The positive terminal of the rectifier diode D4 is connected to the power input module via the switch K4, and the negative terminal is connected to the live wire-to-live wire second detection submodule.

6. The short-circuit detection circuit for an AC charging pile according to claim 2, characterized in that, The short-circuit signal includes a first short-circuit signal, a second short-circuit signal, and a third short-circuit signal; the signal output module includes optocoupler U1, optocoupler U2, and optocoupler U3. Pin 1 of the optocoupler U1 is connected to the neutral-live wire detection module, pin 2 is connected to analog ground, pin 3 is connected to power ground, and pin 4 outputs the first short-circuit signal. Pin 1 of the optocoupler U2 is connected to the live wire-live wire first detection submodule, pin 2 is connected to analog ground, pin 3 is connected to power ground, and pin 4 outputs the second short-circuit signal; Pin 1 of the optocoupler U3 is connected to the second detection submodule of the live wire-live wire, pin 2 is connected to analog ground, pin 3 is connected to power ground, and pin 4 outputs the third short-circuit signal.

7. The short-circuit detection circuit for an AC charging pile according to claim 1, characterized in that, The short-circuit detection circuit also includes a control module; The control module is connected to the signal output module and the output terminal of the AC charging pile. Based on the received short circuit signal, it outputs a fault signal and disconnects the output terminal of the AC charging pile.

8. The short-circuit detection circuit for the AC charging pile according to claim 1, characterized in that, The power input module includes a resistor R1 and a rectifier diode D1; the positive terminal of the rectifier diode D1 is connected to an external isolation power supply to receive the input voltage; the negative terminal of the rectifier diode D1 is connected to the neutral-live wire detection module and the live wire-live wire detection module through the resistor R1.

9. The short-circuit detection circuit for an AC charging pile according to claim 1, characterized in that, The short-circuit detection circuit also includes a detection switch module; The neutral-live wire detection module and the live wire-live wire detection module are connected to the output terminal of the AC charging pile through the detection switch module.

10. An AC charging pile, characterized in that, The short-circuit detection circuit of the AC charging pile as described in any one of claims 1-9 is included.

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