Overvoltage protection circuit and alternating current charging pile

Abstract

The application provides an overvoltage protection circuit and an alternating current charging pile, and belongs to the technical field of intelligent automobiles. The overvoltage protection circuit comprises a voltage sampling unit and an enable control unit. The voltage sampling unit is connected with a charging power supply end of the charging pile and the enable control unit, is used for collecting a sampling voltage of the charging power supply end, and outputs the sampling voltage to the enable control unit. The enable control unit is connected with an auxiliary power supply unit of the charging pile, is used for controlling the auxiliary power supply unit to connect the charging power supply end and a vehicle power supply end of the charging pile in the case that the sampling voltage is less than or equal to an overvoltage threshold, and is used for controlling the auxiliary power supply unit to disconnect the charging power supply end and the vehicle power supply end of the charging pile in the case that the sampling voltage is greater than the overvoltage threshold. The application can realize overvoltage protection of the circuit, and effectively guarantee the charging safety of the vehicle.

Description

Technical Field

[0001] This application relates to the field of intelligent vehicle technology, and in particular to an overvoltage protection circuit and an AC charging pile. Background Technology

[0002] With the development of electric vehicles, charging stations are becoming increasingly common. A charging station is a device used to replenish the electrical energy of electric vehicles, similar to a mobile phone charger. As an electronic device, the circuitry of a charging station has a normal operating voltage range. If the voltage in the circuit exceeds this normal operating voltage range, abnormal circuit operation or even circuit damage may occur, affecting the charging safety of the vehicle.

[0003] Currently, in order to prevent overvoltage damage to charging piles, an overvoltage protection circuit is usually added to the charging circuit that connects the vehicle to the charging pile. This circuit disconnects the voltage loop between the charging circuit and the charging pile when the power supply voltage provided by the charging pile exceeds the normal operating voltage range, thus preventing overvoltage damage to the charging pile's components.

[0004] However, overvoltage protection circuits at the vehicle end typically suffer from complexity and high losses. Furthermore, because the components need to withstand high surge voltages, their cost is usually high. Therefore, overvoltage protection circuits also suffer from high circuit cost. Summary of the Invention

[0005] This application provides an overvoltage protection circuit and an AC charging pile, which can realize overcurrent protection of the circuit and effectively ensure the charging safety of the vehicle.

[0006] In a first aspect, this application provides an overvoltage protection circuit for use in a charging pile, the overvoltage protection circuit including: a voltage sampling unit and an enable control unit;

[0007] The voltage sampling unit is connected to the charging power supply terminal of the charging pile and the enabling control unit, and is used to collect the sampling voltage of the charging power supply terminal and output the sampling voltage to the enabling control unit.

[0008] The enabling control unit is connected to the auxiliary power supply unit of the charging pile. When the sampled voltage is less than or equal to the overvoltage threshold, the auxiliary power supply unit is controlled to connect the charging power supply terminal and the vehicle power supply terminal of the charging pile. When the sampled voltage is greater than the overvoltage threshold, the auxiliary power supply unit is controlled to disconnect the charging power supply terminal and the vehicle power supply terminal of the charging pile.

[0009] Optionally, the auxiliary power supply unit is used to control the connection between the charging power supply terminal and the vehicle power supply terminal under the control of a valid enable signal, and to control the disconnection between the charging power supply terminal and the vehicle power supply terminal under the control of an invalid enable signal; the enable control unit includes: a comparison module and an enable configuration module;

[0010] The comparison module is connected to the voltage sampling unit and the enable configuration module, and is used to control the enable configuration module to output the valid enable signal to the auxiliary power supply unit when the sampled voltage is less than or equal to the overvoltage threshold; and to control the enable configuration module to output the invalid enable signal to the auxiliary power supply unit when the sampled voltage is greater than the overvoltage threshold.

[0011] Optionally, the comparison module is configured to provide a first control signal to the enable configuration module when the sampled voltage is less than or equal to the overvoltage threshold, and to provide a second control signal to the enable configuration module when the sampled voltage is greater than the overvoltage threshold;

[0012] The enable configuration module is also connected to the enable output terminal and the ground terminal of the enable control unit. The enable output terminal is connected to the auxiliary power supply unit and the first power supply terminal, and the ground terminal is grounded. The enable configuration module is used to disconnect the enable output terminal and the ground terminal under the control of the first control signal, and to connect the enable output terminal and the ground terminal under the control of the second control signal.

[0013] Optionally, the enabling configuration module includes: a first switch and a second switch;

[0014] The first switch is connected to the comparison module, the second power supply terminal and the second switch, and is used to disconnect the second power supply terminal and the second switch under the control of the first control signal, and connect the second power supply terminal and the second switch under the control of the second control signal, so as to output the conduction control signal provided by the second power supply terminal to the second switch.

[0015] The second switch is connected to the enable output terminal and the ground terminal, and is used to connect the enable output terminal and the ground terminal under the control of the conduction control signal.

[0016] Optionally, the first switching element is a first transistor, and the second switching element is a second transistor;

[0017] The control terminal of the first transistor is connected to the comparator module, the input terminal of the first transistor is connected to the second power supply terminal, the output terminal of the first transistor is connected to the control terminal of the second transistor, the input terminal of the second transistor is connected to the enable output terminal, and the output terminal of the second transistor is connected to the ground terminal.

[0018] The first transistor is used to turn off under the control of the first control signal and turn on under the control of the second control signal, so as to output the turn-on voltage signal provided by the second power supply terminal to the second transistor;

[0019] The second transistor is turned on under the control of the on-voltage signal to connect the enable output terminal and the ground terminal.

[0020] Optionally, the enabling configuration module includes: an optocoupler;

[0021] The optocoupler is connected to the comparator module, the enable output terminal, and the ground terminal, and is used to disconnect the enable output terminal and the ground terminal under the control of the first control signal, and to connect the enable output terminal and the ground terminal under the control of the second control signal.

[0022] Optionally, the optocoupler includes: a light-emitting diode and a phototransistor, one end of the phototransistor being connected to the enable output terminal, and the other end of the phototransistor being connected to the ground terminal; the enable configuration module further includes: a control element;

[0023] The control unit is connected to the comparison module and the light-emitting diode (LED), and is used to control the LED to stop working under the control of the first control signal to disconnect the enable output terminal and the ground terminal, and to control the LED to work under the control of the second control signal to connect the enable output terminal and the ground terminal.

[0024] Optionally, the control element includes: a third switching element;

[0025] The third switch is connected to the comparison module, the third power supply terminal, and one end of the light-emitting diode (LED). The other end of the LED is connected to the fourth power supply terminal. The third switch is used to disconnect the third power supply terminal and the optocoupler under the control of the first control signal to control the LED to stop working, and to connect the third power supply terminal and the optocoupler under the control of the second control signal to control the LED to work.

[0026] Optionally, the third switching element is a third transistor;

[0027] The control terminal of the third transistor is connected to the comparison module, the input terminal of the third transistor is connected to one end of the light-emitting diode, and the output terminal of the third transistor is connected to the third power supply terminal, for use in turning off under the control of the first control signal and turning on under the control of the second control signal.

[0028] Optionally, the comparison module includes: a three-way voltage regulator;

[0029] The input terminal of the three-way voltage regulator is connected to the voltage sampling unit, and the output terminal of the three-way voltage regulator is connected to the enable configuration module. The three-way voltage regulator is used to control the enable configuration module to output the valid enable signal when the sampled voltage is less than or equal to the overvoltage threshold, and to control the enable configuration module to output the invalid enable signal when the sampled voltage is greater than the overvoltage threshold.

[0030] Optionally, the comparison module includes: a Zener diode, wherein the overvoltage threshold is the breakdown voltage threshold of the Zener diode;

[0031] One end of the Zener diode is connected to the voltage sampling unit, and the other end of the Zener diode is connected to the enable configuration module. The Zener diode is used to control the enable configuration module to output the valid enable signal when the sampled voltage is less than or equal to the overvoltage threshold, and to control the enable configuration module to output the invalid enable signal when the sampled voltage is greater than the overvoltage threshold.

[0032] Optionally, the Zener diode is used to provide a first control signal when the sampled voltage is less than or equal to an overvoltage threshold, and to provide a second control signal when the sampled voltage is greater than the overvoltage threshold; the comparison module further includes: a voltage divider;

[0033] The voltage divider is connected to the Zener diode and the enable configuration module, and is used to perform voltage division processing on the signal provided by the Zener diode and output the divided signal to the enable configuration module.

[0034] Optionally, the comparison module further includes: a filter;

[0035] The filter is connected to the voltage divider and the enable configuration module, and is used to filter the signal provided by the voltage divider and output the filtered signal to the enable configuration module.

[0036] Optionally, the voltage sampling unit includes: a rectifier module and a voltage divider module;

[0037] The rectifier module is connected to the charging power supply terminal and the voltage divider module, and is used to rectify the supply voltage of the charging power supply terminal and output the rectified voltage to the voltage divider module.

[0038] The voltage divider module is connected to the enable control unit and is used to divide the rectified voltage to generate and output the sampled voltage to the enable control unit.

[0039] Optionally, the charging pile is an AC charging pile, and the rectifier module is directly connected to the neutral wire and the live wire of the charging power supply, for rectifying the supply voltage of the neutral wire and the supply voltage of the live wire, generating and outputting a rectified voltage to the voltage divider module.

[0040] Optionally, the rectifier module includes a first diode and a second diode;

[0041] The first diode is connected to the neutral wire terminal and the target node, the second diode is connected to the live wire terminal and the target node, and the target node is connected to the voltage divider module;

[0042] The rectifier module is used to rectify the power supply voltage of the live wire terminal through the first diode and to rectify the power supply voltage of the neutral wire terminal through the second diode, so as to output the rectified voltage to the voltage divider module through the target node.

[0043] Optionally, the charging pile is an AC charging pile, and the charging pile further includes a DC-DC unit. The DC-DC unit is connected to the auxiliary power supply unit, the neutral wire terminal and the live wire terminal of the charging power supply terminal, and is used to convert the power supply voltage provided by the charging power supply terminal into a DC power supply voltage and supply power to the auxiliary power supply unit.

[0044] The rectifier module is connected to the live wire output terminal of the DC-DC unit and is used to rectify the voltage after the power supply voltage at the live wire terminal is processed by the DC-DC unit, generate and output the rectified voltage to the voltage divider module.

[0045] Optionally, the rectifier module includes: a third diode;

[0046] The third diode is connected to the live wire output terminal and the voltage divider module, and is used to rectify the voltage after the power supply voltage of the live wire terminal is processed by the DC-DC unit, and generate and output the rectified voltage to the voltage divider module.

[0047] In a second aspect, a charging pile is provided, comprising: a main controller, a relay, an auxiliary power supply unit, and any of the overvoltage protection circuits described in the first aspect;

[0048] The main controller is connected to the relay and the auxiliary power supply unit. The relay is used to connect the charging power supply terminal of the charging pile and the vehicle power supply terminal under the control of the main controller when it is in the energized state.

[0049] The auxiliary power supply unit is used to supply power to the main controller when a valid enable signal is received, and to stop supplying power to the main controller when an invalid enable signal is received.

[0050] The overvoltage protection circuit is connected to the charging power supply terminal and is used to collect the sampling voltage of the power supply voltage of the charging power supply terminal. When the sampling voltage is less than or equal to the overvoltage threshold, the circuit outputs the valid enable signal to the auxiliary power supply unit. When the sampling voltage is greater than the overvoltage threshold, the circuit outputs the invalid enable signal to the auxiliary power supply unit.

[0051] Compared with prior art, this application has the following advantages:

[0052] In this embodiment, the overvoltage protection circuit applied to the charging pile may include a voltage sampling unit and an enable control unit. The voltage sampling unit is used to collect the sampling voltage of the charging power supply terminal of the charging pile. The enable control unit is used to control the auxiliary power supply unit of the charging pile to connect the charging power supply terminal of the charging pile and the vehicle power supply terminal when the sampling voltage is less than or equal to an overvoltage threshold. Furthermore, the enable control unit is also used to control the auxiliary power supply unit to disconnect the charging power supply terminal of the charging pile and the vehicle power supply terminal when the sampling voltage is greater than the overvoltage threshold.

[0053] In this technical solution, the overvoltage protection circuit can determine whether the sampling voltage of the charging pile is greater than the overvoltage threshold. If the sampling voltage exceeds the overvoltage threshold, indicating that the voltage in the circuit exceeds the normal operating voltage range, the circuit controls the auxiliary power supply unit to disconnect the charging power supply terminal of the charging pile and the vehicle power supply terminal, thus achieving overvoltage protection. This prevents circuit malfunction or even damage caused by the voltage exceeding the normal operating voltage range, effectively ensuring the charging safety of the vehicle. Furthermore, since the overvoltage protection circuit in this application can directly control the existing auxiliary power supply unit of the charging pile to disconnect the charging power supply terminal and the vehicle power supply terminal, this solution, compared to the related technology that adds an overvoltage protection circuit at the vehicle end to disconnect the voltage loop between the charging circuit and the charging pile, effectively reduces the number of devices used to disconnect the voltage loop, thereby reducing the circuit complexity of the overvoltage protection circuit at the vehicle end, and consequently reducing circuit losses and costs.

[0054] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0055] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the accompanying drawings used in the description of the embodiments will be briefly introduced below.

[0056] Figure 1 This is a schematic diagram of the structure of a charging pile provided in an embodiment of this application;

[0057] Figure 2 This is a schematic diagram of an overvoltage protection circuit provided in an embodiment of this application;

[0058] Figure 3 This is a schematic diagram of an overvoltage protection circuit provided in an embodiment of this application;

[0059] Figure 4 This is a schematic diagram of an overvoltage protection circuit provided in an embodiment of this application;

[0060] Figure 5 This is a schematic diagram of an overvoltage protection circuit provided in an embodiment of this application;

[0061] Figure 6 This is a schematic diagram of an overvoltage protection circuit provided in an embodiment of this application;

[0062] Figure 7 A timing diagram of an overvoltage protection circuit provided in an embodiment of this application;

[0063] Figure 8 This is a schematic diagram of a charging pile provided in an embodiment of this application. Detailed Implementation

[0064] Exemplary embodiments of the present application will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present application are shown in the drawings, it should be understood that the present application may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this application will be thorough and complete, and will fully convey the scope of the present application to those skilled in the art.

[0065] Please refer to Figure 1 The diagram illustrates a structural schematic of a charging pile according to an embodiment of this application. Figure 1 As shown, the charging pile 1 includes: an auxiliary power supply unit 30, and an overvoltage protection circuit 40 provided in this embodiment. The auxiliary power supply unit 30 is used to control the connection or disconnection between the charging power supply terminal and the vehicle power supply terminal.

[0066] Optionally, the auxiliary power supply unit 30 is used to connect the charging power supply terminal L / N and the vehicle power supply terminal Lout-Nout under the control of a valid enable signal, and to disconnect the charging power supply terminal L / N and the vehicle power supply terminal Lout-Nout under the control of an invalid enable signal.

[0067] Alternatively, the charging pile 1 may further include a main controller 10 and a relay 20. The main controller 10 is connected to the relay 20 and the auxiliary power supply unit 30.

[0068] Relay 20 is used to connect or disconnect the charging power supply terminal L / N and the vehicle power supply terminal Lout-Nout of the charging pile 1 under the control of the main controller 10. Specifically, relay 20 can be used to connect the charging power supply terminal L / N and the vehicle power supply terminal Lout-Nout of the charging pile 1 under the control of the main controller 10 when it is energized. Correspondingly, when the main controller 10 is not energized, relay 20 cannot be controlled to connect the charging power supply terminal L / N and the vehicle power supply terminal Lout-Nout of the charging pile 1.

[0069] The auxiliary power supply unit 30 is used to supply power to the main controller 10 when a valid enable signal VEM is received, and to stop supplying power to the main controller 10 when an invalid enable signal VEM is received. Specifically, the auxiliary power supply unit 30 is used to output the main control power supply voltage V5 to the main controller 10 when a valid enable signal VEM is received, and to stop outputting the main control power supply voltage V5 to the main controller 10 when an invalid enable signal VEM is received, thereby stopping the supply of power to the main controller 10.

[0070] Please refer to Figure 2 The diagram illustrates a structural schematic of an overvoltage protection circuit provided in an embodiment of this application. The overvoltage protection circuit is applied to a charging pile. The auxiliary power supply unit in the charging pile is used to control the connection or disconnection between the charging power supply terminal and the vehicle power supply terminal. Optionally, the charging pile can be... Figure 1 The charging station shown. Figure 2 As shown, the overvoltage protection circuit 40 includes a voltage sampling unit 401 and an enable control unit 402.

[0071] The voltage sampling unit 401 is connected to the charging power supply terminal L / N of the charging pile and the enable control unit 402. The voltage sampling unit 401 is used to collect the sampling voltage V1 of the charging power supply terminal L / N and output the sampling voltage V1 to the enable control unit 402.

[0072] The enable control unit 402 is connected to the auxiliary power supply unit 30 of the charging pile. The enable control unit 402 is used to control the auxiliary power supply unit 402 to connect the charging power supply terminal L / N of the charging pile 1 and the vehicle power supply terminal Lout-Nout when the sampled voltage V1 is less than or equal to the overvoltage threshold.

[0073] The enable control unit 402 is also used to control the disconnection of the charging power supply terminal L / N and the vehicle power supply terminal Lout-Nout of the charging pile 1 from the auxiliary power supply unit 402 when the sampled voltage V1 is greater than the overvoltage threshold.

[0074] In some embodiments, the auxiliary power supply unit 30 is used to control the connection between the charging power supply terminal L / N and the vehicle power supply terminal Lout-Nout under the control of an effective enable signal, and to control the disconnection between the charging power supply terminal L / N and the vehicle power supply terminal Lout-Nout under the control of an invalid enable signal.

[0075] Optionally, the enable control unit 402 is used to output a valid enable signal to the auxiliary power supply unit 402 when the sampled voltage V1 is less than or equal to the overvoltage threshold, so as to control the auxiliary power supply unit 402 to connect the charging power supply terminal L / N of the charging pile 1 and the vehicle power supply terminal Lout-Nout.

[0076] The enable control unit 402 is also used to output an invalid enable signal to the auxiliary power supply unit 402 when the sampled voltage V1 is greater than the overvoltage threshold, so as to control the auxiliary power supply unit 402 to disconnect the charging power supply terminal L / N and the vehicle power supply terminal Lout-Nout of the charging pile 1.

[0077] Alternatively, the auxiliary power supply unit 30 controls the main controller 10 to be connected or disconnected by whether or not it supplies power to the main controller 10.

[0078] The enable control unit 402 is used to output a valid enable signal to the auxiliary power supply unit 402 when the sampled voltage V1 is less than or equal to the overvoltage threshold, so that the auxiliary power supply unit 30 supplies power to the main controller 10, thereby energizing the main controller 10 to control the relay 20 to connect the charging power supply terminal L / N of the charging pile 1 and the vehicle power supply terminal Lout-Nout.

[0079] The enable control unit 402 is also used to output an invalid enable signal to the auxiliary power supply unit 402 when the sampled voltage V1 is greater than the overvoltage threshold, so that the auxiliary power supply unit 30 stops supplying power to the main controller 10, thereby causing the main controller 10 to disconnect and be unable to control the relay 20 to connect the charging power supply terminal L / N and the vehicle power supply terminal Lout-Nout of the charging pile 1.

[0080] In some embodiments of this application, such as Figure 1 As shown, the charging pile 1 also includes a switch control unit 50. The switch control unit 50 is connected to the main controller 10, the relay 20, and the ground terminal GND1. The ground terminal GND1 is grounded. The relay 20 is also connected to the fifth power supply terminal VCC5, which is used to provide a positive voltage to the relay 20.

[0081] The main controller 10 can output a third control signal to the switch control unit 50 when it is powered on. Upon receiving the third control signal, the switch control unit 50 connects the relay 20 and the ground terminal GND1, so that the relay 20 forms a power-on circuit and then closes, connecting the charging power supply terminal L / N of the charging pile 1 and the vehicle power supply terminal Lout-Nout.

[0082] Accordingly, the main controller 10 cannot output the third control signal to the switch control unit 50 when it is powered off. Without receiving the third control signal, the switch control unit 50 disconnects the relay 20 and the ground terminal GND1, preventing the relay 20 from forming a power circuit, and disconnects the charging power supply terminal L / N of the charging pile 1 and the vehicle power supply terminal Lout-Nout.

[0083] For example, the switch control unit 50 includes a transistor Q11, and correspondingly, the third control signal is a third on-voltage signal. The gate of transistor Q11 is connected to the main controller 10, the collector of transistor Q11 is connected to the relay 20, and the emitter of transistor Q11 is grounded through the ground terminal GND1.

[0084] The main controller 10 outputs a third conduction voltage signal to the gate of transistor Q11 when it is powered on, thereby controlling the conduction of the collector and emitter of transistor Q11, connecting relay 20 and ground terminal GND1, and forming a power-on circuit for electrical appliance 20. When the main controller 10 is powered off and cannot output the third control signal to the switch control unit 50, transistor Q11 disconnects its collector and emitter because its gate does not receive the third conduction voltage, thus disconnecting relay 20 and ground terminal GND1, preventing relay 20 from forming a power-on circuit.

[0085] In some embodiments of this application, the voltage sampling unit 401 can be used to collect the sampling voltage V1 of the supply voltage V0 of the charging power supply terminal L / N, and output a valid enable signal to the auxiliary power supply unit 402 when the sampling voltage V1 is less than or equal to the overvoltage threshold, indicating that the supply voltage V0 has not exceeded the normal voltage. At this time, the auxiliary power supply unit 30 is used to supply power to the main controller 10. The main controller 10 is used to control the relay 20 to connect the charging power supply terminal L / N of the charging pile 1 and the vehicle power supply terminal Lout-Nout.

[0086] The voltage sampling unit 401 can also be used to collect the sampling voltage V0 of the power supply voltage V0 at the charging power supply terminal L / N, and when the sampling voltage V1 is greater than the overvoltage threshold, indicating that the power supply voltage V0 exceeds the normal voltage, it outputs an enable signal to the auxiliary power supply unit 402. At this time, the auxiliary power supply unit 30 is used to stop supplying power to the main controller 10. The main controller 10 is used to control the relay 20 to disconnect the charging power supply terminal L / N of the charging pile 1 and the vehicle power supply terminal Lout-Nout.

[0087] It should be noted that in some embodiments, the charging pile can be an AC charging pile. Therefore, the charging power supply terminal L / H of the charging pile can include a neutral terminal N, a live terminal L, and a ground terminal PE. Correspondingly, the vehicle power supply terminal Lout-Hout can include: the vehicle neutral power supply terminal Nout, the vehicle live power supply terminal Lout, and the vehicle ground power supply terminal PE-out. Figure 1 The illustration uses an AC charging pile as an example. Alternatively, the main controller 10 can be a microcontroller unit (MCU).

[0088] In this embodiment, the overvoltage protection circuit applied to the charging pile may include a voltage sampling unit and an enable control unit. The voltage sampling unit is used to collect the sampling voltage of the charging power supply terminal of the charging pile. The enable control unit is used to control the auxiliary power supply unit of the charging pile to connect the charging power supply terminal of the charging pile and the vehicle power supply terminal when the sampling voltage is less than or equal to an overvoltage threshold. Furthermore, the enable control unit is also used to control the auxiliary power supply unit to disconnect the charging power supply terminal of the charging pile and the vehicle power supply terminal when the sampling voltage is greater than the overvoltage threshold.

[0089] In this technical solution, the overvoltage protection circuit can determine whether the sampling voltage of the charging pile is greater than the overvoltage threshold. If the sampling voltage exceeds the overvoltage threshold, indicating that the voltage in the circuit exceeds the normal operating voltage range, the circuit controls the auxiliary power supply unit to disconnect the charging power supply terminal of the charging pile and the vehicle power supply terminal, thus achieving overvoltage protection. This prevents circuit malfunction or even damage caused by the voltage exceeding the normal operating voltage range, effectively ensuring the charging safety of the vehicle. Furthermore, since the overvoltage protection circuit in this application can directly control the existing auxiliary power supply unit of the charging pile to disconnect the charging power supply terminal and the vehicle power supply terminal, this solution, compared to the related technology that adds an overvoltage protection circuit at the vehicle end to disconnect the voltage loop between the charging circuit and the charging pile, effectively reduces the number of devices used to disconnect the voltage loop, thereby reducing the circuit complexity of the overvoltage protection circuit at the vehicle end, and consequently reducing circuit losses and costs.

[0090] Furthermore, by directly cutting off the power supply to the main controller, the relay loses its drive signal and disconnects the charging power supply from the vehicle power supply, thus directly and effectively achieving circuit protection. Compared to using the overcurrent protection program set in the main controller to execute circuit overcurrent protection, this effectively eliminates the problem of circuit overcurrent protection failure caused by program failure, effectively ensuring the execution timeliness of circuit overcurrent protection and improving the charging safety of the vehicle.

[0091] In some embodiments of this application, such as Figure 3 As shown, the enable control unit 402 may include a comparison module 4021 and an enable configuration module 4022.

[0092] The comparison module 4021 is connected to the voltage sampling unit 401 and the enable configuration module 4022. The comparison module 4021 controls the enable configuration module 4022 to output a valid enable signal when the sampled voltage is less than or equal to an overvoltage threshold. The comparison module 4021 also controls the enable configuration module 4022 to output an invalid enable signal when the sampled voltage is greater than the overvoltage threshold.

[0093] Optionally, the comparison module 4021 provides a first control signal to the enable configuration module 4022 when the sampled voltage is less than or equal to an overvoltage threshold, and provides a second control signal to the enable configuration module 4022 when the sampled voltage is greater than the overvoltage threshold. The first control signal controls the enable configuration module 4022 to output a valid enable signal to the main controller 10. The second control signal controls the enable configuration module 4022 to output an invalid enable signal to the main controller 10.

[0094] Optionally, the enable configuration module 4022 is also connected to the enable output terminal EN-out and the ground terminal GND2 of the enable control unit. The enable output terminal EN-out is connected to the auxiliary power supply unit 30 and the first power supply terminal VCC1, and the ground terminal GND2 is grounded.

[0095] The enable configuration module 4022, under the control of the first control signal, disconnects the enable output terminal EN-out and the ground terminal GND2, so that the first power supply terminal VCC1 provides a valid enable signal VEN to the enable output terminal EN-out. The enable configuration module 4022 is also used, under the control of the second control signal, to connect the enable output terminal EN-out and the ground terminal GND2, thereby pulling the enable output terminal EN-out low, so that the enable output terminal EN-out outputs an invalid enable signal VEN. The valid enable signal VEN is a high-level signal, and the invalid enable signal VEN is a low-level signal.

[0096] In this embodiment, the enable configuration module 4022 can have various structures to support its functions. The following describes three illustrative examples of the enable configuration module 4022's structures.

[0097] In the first alternative case, such as Figure 4 As shown, the enable configuration module 4022 may include: a first switch 40221 and a second switch 40222.

[0098] The first switch 40221 is connected to the comparator module 4021, the second power supply terminal VCC2, and the second switch 40222. The first switch 40221 is also used to disconnect the second power supply terminal VCC2 and the second switch 40222 under the control of a first control signal, thereby stopping the output of the conduction control signal provided by the second power supply terminal VCC2 to the second switch 40222. The second switch 40222 is used to disconnect the enable output terminal EN-out and the ground terminal GND2 when no conduction control signal is received, so that the enable output terminal EN-out outputs the valid enable signal EN provided by the first power supply terminal VCC1.

[0099] The first switch 40221 is used to connect the second power supply terminal VCC2 and the second switch 40222 under the control of the second control signal, so as to output the conduction control signal provided by the second power supply terminal VCC2 to the second switch 40222. The second switch 40222 is connected to the enable output terminal EN-out and the ground terminal GND2. The second switch 40222 is used to connect the enable output terminal EN-out and the ground terminal GND2 under the control of the conduction control signal, so that the enable output terminal EN-out outputs an invalid enable signal EN.

[0100] Optionally, the first switching element 40221 can be a first transistor Q1, and the second switching element 40222 can be a second transistor Q2. The control terminal of the first transistor Q1 is connected to the comparator module 4021, the input terminal of the first transistor Q1 is connected to the second power supply terminal VCC2, and the output terminal of the first transistor Q1 is connected to the control terminal of the second transistor Q2. The input terminal of the second transistor Q2 is connected to the enable output terminal EN-out, and the output terminal of the second transistor Q2 is connected to the ground terminal GND2.

[0101] The first transistor Q1 is turned off under the control of the first control signal to stop outputting the conduction control signal to the control terminal of the second transistor Q2. The second transistor Q2 is turned off when no conduction control signal is received to disconnect the enable output terminal EN-out and the ground terminal GND2, so that the enable output terminal EN-out outputs the valid enable signal EN provided by the first power supply terminal VCC1.

[0102] The first transistor Q1 is also turned on under the control of the second control signal to output the turn-on voltage signal provided by the second power supply terminal VCC2 to the second transistor Q2. The second transistor Q2 is turned on under the control of the turn-on voltage signal to connect the enable output terminal EN-out and the ground terminal GND2, so that the enable output terminal EN-out outputs an invalid enable signal EN.

[0103] For example, the first transistor Q1 can be a PMOS transistor, and the second transistor Q2 can be a bipolar transistor. Alternatively, the first transistor Q1 can be a PMOS transistor, and the second transistor Q2 can be an NMOS transistor. It should be noted that the transistors involved in the technical solutions of this application (e.g., the first transistor Q1, the second transistor Q2, etc.) all conform to the following description. When the transistor is a PMOS transistor, the control terminal refers to the gate of the PMOS transistor, the input terminal refers to the source of the PMOS transistor, and the output terminal refers to the drain of the PMOS transistor. When the transistor is an NMOS transistor, the control terminal refers to the gate of the PMOS transistor, the input terminal refers to the drain of the PMOS transistor, and the output terminal refers to the source of the PMOS transistor. When the transistor is a bipolar transistor, the control terminal refers to the gate of the bipolar transistor, the input terminal refers to the collector of the bipolar transistor, and the output terminal refers to the emitter of the bipolar transistor.

[0104] As a further example, such as Figure 4 As shown, the enable configuration module 4022 also includes: a seventh resistor R7, an eighth resistor R8, and a ninth resistor R9.

[0105] The comparator module 4021 is also connected to the input terminal of the first transistor Q1 via a seventh resistor R7, and the output terminal of the first transistor Q1 is connected to the control terminal of the second transistor Q2 via an eighth resistor R8. Furthermore, the output terminal of the first transistor Q1 is also connected to the output terminal of the second transistor Q2 via an eighth resistor R8.

[0106] In the second alternative scenario, such as Figure 5 As shown, the enable configuration module 4022 may include: an optocoupler U51.

[0107] Optocoupler U51 is connected to comparator module 4021, enable output terminal EN-out, and ground terminal GND2. Optocoupler U51 is used to disconnect enable output terminal EN-out and ground terminal GND2 under the control of a first control signal, and to connect enable output terminal EN-out and ground terminal GND2 under the control of a second control signal.

[0108] Optionally, the optocoupler U51 may include a light-emitting diode (LED) and a phototransistor. The LED is connected to the comparator module 4021. One end of the phototransistor is connected to the enable output terminal EN-out, and the other end of the phototransistor is connected to the ground terminal GND2.

[0109] The LED in optocoupler U51 is used to stop operating under the control of the first control signal, so that the phototransistor will not conduct due to receiving light emitted by the LED, thus disconnecting the enable output terminal EN-out and the ground terminal GND2. The LED in optocoupler U51 is also used to operate under the control of the second control signal, so that the phototransistor can receive light emitted by the LED and conduct, thereby connecting the enable output terminal EN-out and the ground terminal GND2.

[0110] In the third alternative case, such as Figure 6 As shown, the enable configuration module 4022 may include: an optocoupler U61 and a control element 40223.

[0111] The optocoupler U61 may include a light-emitting diode (LED) and a phototransistor. One end of the phototransistor is connected to the enable output terminal EN-out, and the other end is connected to the ground terminal GND2. The control unit 40223 is connected to the comparator module 4021 and the LED.

[0112] The control unit 40223 is used to control the light-emitting diode to stop working under the control of the first control signal, so that the phototransistor will not conduct due to receiving the light emitted by the light-emitting diode, thus disconnecting the enable output terminal EN-out and the ground terminal GND2. The control unit 40223 is also used to control the light-emitting diode to work under the control of the second control signal, so that the phototransistor can receive the light emitted by the light-emitting diode and conduct, thereby connecting the enable output terminal EN-out and the ground terminal GND2.

[0113] Alternatively, please continue to refer to Figure 6 The control unit 40223 may include a third switch. The third switch is connected to the comparator module 4021, the third power supply terminal VCC3, and one end of the light-emitting diode, and the other end of the light-emitting diode is connected to the fourth power supply terminal VCC4.

[0114] The third switch is used to disconnect the third power supply terminal VCC3 and the optocoupler U61 under the control of the first control signal, so that one end of the light-emitting diode stops working because it does not receive voltage, thereby controlling the light-emitting diode to stop working and disconnecting the enable output terminal EN-out and the ground terminal GND2.

[0115] The third switching element is also used to connect the third power supply terminal VCC3 and the optocoupler U61 under the control of the second control signal, so that one end of the light-emitting diode can receive voltage and work, thereby controlling the light-emitting diode to work, and connecting the enable output terminal EN-out and the ground terminal GND2.

[0116] For example, please continue to refer to Figure 6 The third switching element can be a third transistor Q3. The control terminal of the third transistor Q3 is connected to the comparator module 4021, the input terminal of the third transistor Q3 is connected to one end of the light-emitting diode, and the output terminal of the third transistor Q3 is connected to the third power supply terminal VCC3.

[0117] The third transistor Q3 can be turned off under the control of the first control signal to disconnect the third power supply terminal VCC3 and the optocoupler U61. The third transistor Q3 can also be turned on under the control of the second control signal to connect the third power supply terminal VCC3 and the optocoupler U61. In an optional implementation, the third transistor Q3 can be a transistor or a MOSFET.

[0118] For further examples, please refer to [link / reference]. Figure 6 The enable configuration module 4022 also includes a thirteenth resistor R13. The other end of the light-emitting diode is connected to the fourth power supply terminal VCC4 through the thirteenth resistor R13.

[0119] In this embodiment of the application, similar to the enable configuration module 4022, the comparison module 4021 may also have multiple structures to support its functions. The following illustrative description uses three structures of the comparison module 4021 as examples.

[0120] In the first alternative implementation, such as Figure 4 As shown, the comparison module 4021 may include: a three-way voltage regulator U71.

[0121] The input terminal of the three-way voltage regulator U71 is connected to the voltage sampling unit 401, and the output terminal of the three-way voltage regulator U71 is connected to the enable configuration module 4022. The ground terminal of the three-way voltage regulator U71 is grounded through the ground terminal GND3.

[0122] The three-way voltage regulator U71 is used to control the enable configuration module 4022 to output a valid enable signal when the sampled voltage is less than or equal to the overvoltage threshold, and to control the enable configuration module 4022 to output an invalid enable signal when the sampled voltage is greater than the overvoltage threshold.

[0123] The input voltage range of the three-way voltage regulator U71 can be set by configuring the parameters of each component within it, with the overvoltage threshold serving as the critical value within this range. Optionally, the three-way voltage regulator U71 can output a first control signal to the enable configuration module 4022 when the sampled voltage is less than or equal to the overvoltage threshold. This causes the enable configuration module 4022 to disconnect the enable output terminal EN-out and the ground terminal GND2 under the control of the first control signal, thereby outputting a valid enable signal provided by the first power supply terminal VCC1. The three-way voltage regulator U71 can also output a second control signal to the enable configuration module 4022 when the sampled voltage is greater than the overvoltage threshold. This causes the enable configuration module 4022 to connect the enable output terminal EN-out and the ground terminal GND2 under the control of the second control signal, controlling the enable configuration module 4022 to output an invalid enable signal.

[0124] In the second alternative implementation, such as Figure 6 As shown, the comparison module 4021 may include a Zener diode ZD81. The overvoltage threshold can be the breakdown voltage threshold of the Zener diode ZD81.

[0125] One end of the Zener diode ZD81 is connected to the voltage sampling unit 401, and the other end of the Zener diode ZD81 is connected to the enable configuration module 4022.

[0126] The Zener diode ZD81 is used to enter the cutoff state when the sampled voltage is less than or equal to the overvoltage threshold, and control the enable configuration module 4022 to output a valid enable signal; when the sampled voltage is greater than the overvoltage threshold, it enters the breakdown state, and controls the enable configuration module 4022 to output an invalid enable signal.

[0127] Optionally, the anode of the Zener diode ZD81 is connected to the voltage sampling unit 401, and the cathode of the Zener diode ZD81 is connected to the enable configuration module 4022. When the Zener diode ZD81 is in the off state, the cathode voltage of the Zener diode ZD81 is low. Therefore, a first control signal with a low voltage can be provided to the enable configuration module 4022, so that the enable configuration module 4022 disconnects the enable output terminal EN-out and the ground terminal GND2 under the control of the first control signal, thereby outputting an effective enable signal provided by the first power supply terminal VCC1.

[0128] When the Zener diode ZD81 is in a breakdown state, the cathode voltage of the Zener diode ZD81 is relatively high. Therefore, a second control signal with a higher voltage can be provided to the enable configuration module 4022, so that the enable configuration module 4022 connects the enable output terminal EN-out and the ground terminal GND2 under the control of the second control signal, and controls the enable configuration module 4022 to output an invalid enable signal.

[0129] In the third alternative implementation, such as Figure 5 As shown, the comparison module 4021 may include a Zener diode ZD91 and a voltage divider 40211. The overvoltage threshold can be the breakdown voltage threshold of the Zener diode ZD91.

[0130] The anode of the Zener diode ZD91 is connected to the voltage sampling unit 401, and the cathode of the Zener diode ZD91 is connected to the voltage divider 4022 and the enable configuration module 4022. The Zener diode ZD91 is used to provide a first control signal when the sampled voltage is less than or equal to the overvoltage threshold, and to provide a second control signal when the sampled voltage is greater than the overvoltage threshold.

[0131] Specifically, when Zener diode ZD91 is in the off state, the cathode voltage of Zener diode ZD81 is low, thus providing a lower voltage first control signal to voltage divider 40211. Voltage divider 40211 divides the first control signal and outputs the divided first control signal to enable configuration module 4022. Under the control of the divided first control signal, enable configuration module 4022 disconnects the enable output terminal EN-out and the ground terminal GND2, thereby outputting a valid enable signal provided by the first power supply terminal VCC1.

[0132] When the Zener diode ZD91 is in a breakdown state, its cathode voltage is relatively high. Therefore, it can provide a higher voltage second control signal to the voltage divider 40211. The voltage divider 40211 divides the second control signal and outputs the divided second control signal to the enable configuration module 4022. Under the control of the divided second control signal, the enable configuration module 4022 connects the enable output terminal EN-out and the ground terminal GND2, controlling the enable configuration module 4022 to output an invalid enable signal.

[0133] For example, such as Figure 5 As shown, the voltage divider 40211 includes a first resistor R1 and a second resistor R2. One end of the first resistor R1 is connected to the Zener diode ZD91, and the other end of the first resistor R1 is connected to one end of the second resistor R2 and the enable configuration module 4022. The other end of the second resistor R2 is grounded. The voltage divider 40211 is used to divide the signal provided by the Zener diode ZD91 according to the resistance values ​​of the first resistor R1 and the second resistor R2, and output the divided signal to the enable configuration module 4022.

[0134] Optionally, the comparison module 4021 further includes a filter 40212. The filter 40212 is connected to the voltage divider 40211 and the enable configuration module 4022. The filter 40212 is used to filter the signal provided by the voltage divider 40211 and output the filtered signal to the enable configuration module 4022.

[0135] Specifically, filter 40212 filters the first control signal transmitted by voltage divider 40211 and outputs the filtered first control signal to enable configuration module 4022. Filter 40212 also filters the second control signal transmitted by voltage divider 40211 and outputs the filtered second control signal to enable configuration module 4022. Filter 40212 effectively filters out noise from the first and second control signals, preventing interference signals from the power grid connected to the charging pile from interfering with the overvoltage protection circuit and effectively preventing malfunctions of the overvoltage protection circuit caused by power grid interference.

[0136] For example, such as Figure 5 As shown, filter 40212 includes a first capacitor C1 and a third resistor R3. One end of the first capacitor C1 is connected to voltage divider 40211, and the other end of the first capacitor C1 is grounded. One end of the third resistor R3 is connected to voltage divider 40211, and the other end of the third resistor R3 is connected to enable configuration module 4022. The first capacitor C1 and the third resistor R3 work together to filter the signal provided by voltage divider 40211 and output the filtered signal to enable configuration module 4022.

[0137] It should be noted that the foregoing has described three structures of enable configuration modules 4022 and three structures of comparison modules 4021. Enable configuration modules 4022 and comparison modules 4021 with different structures can be combined to form enable control units 402 with different structures. The specific combination method is not limited in this embodiment, and will be described exemplarily later.

[0138] In this embodiment, similar to the enable control unit 402, the voltage sampling unit 401 can also have various structures to support its functions. The following illustrative description uses two structures of the voltage sampling unit 401 as examples.

[0139] Optionally, such as Figure 4 As shown, the voltage sampling unit 401 may include a rectifier module 4011 and a voltage divider module 4012.

[0140] The rectifier module 4011 is connected to the charging power supply terminal L / N and the voltage divider module 4012. The rectifier module 4011 rectifies the supply voltage at the charging power supply terminal L / N and outputs the rectified voltage to the voltage divider module 4012. The voltage divider module 4012 is connected to the enable control unit 402. The voltage divider module 4012 divides the rectified voltage to generate and output a sampling voltage V1 to the enable control unit 402.

[0141] In the first alternative implementation, such as Figure 4As shown, charging pile 1 is an AC charging pile. Charging pile 1 also includes a DC-DC unit 60. The DC-DC unit 60 is connected to the auxiliary power supply unit 30, the neutral terminal N and the live terminal L of the charging power supply terminal L / N. The DC-DC unit 60 is used to convert the power supply voltage provided by the charging power supply terminal L / N into a DC power supply voltage and supply power to the auxiliary power supply unit 30.

[0142] The rectifier module 4011 can be connected to the live wire output terminal of the DC-DC unit 60. The live wire output terminal of the DC-DC unit 60 is used to output the DC supply voltage after converting the supply voltage provided by the live wire terminal L. The rectifier module 4011 can be used to rectify the voltage after the supply voltage of the live wire terminal L has been processed by the DC-DC unit 60, and generate and output the rectified voltage to the voltage divider module 4012. The voltage divider module 4012 is used to divide the rectified voltage, and generate and output the sampling voltage V1 to the enable control unit 402.

[0143] Optionally, such as Figure 4 As shown, the rectifier module 4011 includes a third diode D3. The third diode D3 is connected to the live wire output of the DC-DC unit 60 and the voltage divider module 4012. The third diode D3 is used to rectify the DC voltage after the power supply voltage of the live wire terminal L is processed by the DC-DC unit 60, and generate and output the rectified voltage to the voltage divider module 4012.

[0144] Further optional, such as Figure 4 As shown, the voltage divider module 4012 includes a fourth resistor R4 and a fifth resistor R5. One end of the fourth resistor R4 is connected to the third diode D3, and the other end of the fourth resistor R4 is connected to the enable control unit 402 and one end of the fifth resistor R5. The other end of the fifth resistor R5 is grounded. The voltage divider module 4012 is used to divide the rectified voltage output by the rectifier module 4011 according to the resistance of the fourth resistor R4 and the fifth resistor R5 to obtain the sampling voltage V1.

[0145] In some embodiments, please refer to Figure 4 The voltage sampling unit 401 may further include a filter capacitor C2 and an RC filter circuit. The RC filter circuit includes a sixth resistor R6 and a third capacitor C3. One end of the filter capacitor C2 is connected to the third diode D3 and the fourth resistor R4, and the other end of the filter capacitor C2 is grounded. The filter capacitor C2 is used to filter the rectified voltage transmitted by the third diode D3 to prevent interference signals from the power grid from interfering with subsequent circuits.

[0146] The other end of the fourth resistor R4 is connected to the enable control unit 402 through the sixth resistor R6, and one end of the fifth resistor R5 is also connected to the enable control unit 402 through the sixth resistor R6. One end of the third capacitor C3 is connected to the enable control unit 402, and the other end of the third capacitor is grounded. The sixth resistor R6 and the third capacitor C3 work together to further filter the sampled voltage V1, outputting the filtered sampled voltage V1 to the enable control unit 402.

[0147] In the second alternative implementation, such as Figure 6 As shown, charging pile 1 is an AC charging pile, and the rectifier module 4011 is directly connected to the neutral wire N and the live wire L of the charging power supply terminal L / N.

[0148] The rectifier module 4011 rectifies the supply voltage at the neutral terminal N and the supply voltage at the live terminal L, generating and outputting the rectified voltage to the voltage divider module 4012. The voltage divider module 4012 divides the rectified voltage, generating and outputting the sampling voltage V1 to the enable control unit 402.

[0149] Optionally, such as Figure 6 As shown, the rectifier module 4011 includes a first diode D1 and a second diode D2. The first diode D1 is connected to the neutral terminal N and the target node O1, and the second diode D2 is connected to the live terminal L and the target node O1. The target node O1 is connected to the voltage divider module 4012.

[0150] The rectifier module 4011 is used to rectify the power supply voltage of the live wire terminal L through the first diode D1 and to rectify the power supply voltage of the neutral wire terminal N through the second diode D2, so as to output the rectified voltage to the voltage divider module 4012 through the target node O1.

[0151] Further optional, such as Figure 6 As shown, the voltage divider module 4012 includes a tenth resistor R10 and an eleventh resistor R11. One end of the tenth resistor R10 is connected to the target node O1, and the other end of the tenth resistor R10 is connected to the enable control unit 402 and one end of the eleventh resistor R11, respectively. The other end of the eleventh resistor R11 is grounded. The voltage divider module 4012 is used to divide the rectified voltage transmitted by the rectifier module 4011 according to the resistance values ​​of the tenth resistor R10 and the eleventh resistor R11, and generate and output a sampling voltage V1 to the enable control unit 402.

[0152] In some embodiments, please refer to Figure 6The voltage sampling unit 401 may further include an RC filter circuit. This RC filter circuit includes a twelfth resistor R12 and a fourth capacitor C4. One end of the twelfth resistor R12 is connected to both the tenth resistor R10 and the eleventh resistor R11, and the other end is connected to the enable control unit 402. One end of the fourth capacitor C4 is connected to the tenth resistor R10, the eleventh resistor R11, and the twelfth resistor R12, and the other end is grounded. The twelfth resistor R12 and the fourth capacitor C4 work together to further filter the sampled voltage V1, outputting the filtered sampled voltage V1 to the enable control unit 402.

[0153] In this embodiment, the overvoltage protection circuit can determine whether the supply voltage of the charging pile is greater than the overvoltage threshold. If the supply voltage is greater than the overvoltage threshold, indicating that the voltage in the circuit exceeds the normal operating voltage range, the circuit controls the auxiliary power supply unit to stop supplying power to the main controller. This causes the relay to disconnect the charging power supply terminal of the charging pile from the vehicle power supply terminal, thus achieving overvoltage protection of the circuit. This prevents abnormal circuit operation or even circuit damage caused by the voltage in the circuit exceeding the normal operating voltage range, effectively ensuring the charging safety of the vehicle. Furthermore, directly cutting off the power supply to the main controller, causing the relay to lose its drive signal and directly disconnect the charging power supply terminal and the vehicle power supply terminal, can directly and effectively achieve circuit protection. Compared to using the overvoltage protection program set in the main controller to execute the circuit overvoltage protection, this effectively eliminates the problem of circuit overvoltage protection failure caused by program failure, effectively ensuring the execution timeliness of circuit overvoltage protection and improving the charging safety of the vehicle.

[0154] For ease of understanding, the overvoltage protection circuit provided in the embodiments of this application is illustrated below with three examples. For example, as shown... Figure 4 As shown, the overvoltage protection circuit 40 includes a voltage sampling unit 401 and an enable control unit 402.

[0155] The voltage sampling unit 401 is the voltage sampling unit 401 in the first case, specifically including: a third diode D3, a fourth resistor R4, a fifth resistor R5, a filter capacitor C2, a sixth resistor R6, and a third capacitor C3. The comparator module 4021 in the enable control unit 402 is the comparator module 4021 in the first case, specifically including: a three-way regulator U71. The enable configuration module 4022 in the enable control unit 402 is the enable configuration module 4022 in the first case, specifically including: a first transistor Q1, a second transistor Q2, a seventh resistor R7, an eighth resistor R8, and a ninth resistor R9.

[0156] The anode of the third diode D3 is connected to the live wire output of the DC-DC unit 60, and the cathode of the third diode D3 is grounded through the filter capacitor C2. Furthermore, the cathode of the third diode D3 is connected to the input terminal of the three-way voltage regulator U71 in sequence through the fourth resistor R4 and the sixth resistor R6. The first end of the fifth resistor R5 is connected to the path between the fourth resistor R4 and the sixth resistor R6, and the second end of the fifth resistor R5 is grounded. One end of the third capacitor C3 is connected to the sixth resistor R6, and the other end of the third capacitor C3 is grounded. The ground terminal of the three-way voltage regulator U71 is grounded, and the output terminal of the three-way voltage regulator U71 is connected to the gate of the first transistor Q1. The output terminal of the three-way voltage regulator U71 is also connected to the input terminal of the first transistor Q1 through the seventh resistor R7. The input terminal of the first transistor Q1 is connected to the second power supply terminal VCC2. The output terminal of the first transistor Q1 is connected to the control terminal of the second transistor Q2 through the eighth resistor R8. Furthermore, the output terminal of the first transistor Q1 is also connected to the output terminal of the second transistor Q2 through the eighth resistor R8. The input terminal of the second transistor Q2 is connected to the enable output terminal EN-out, and the output terminal of the second transistor Q2 is connected to the ground terminal GND2.

[0157] exist Figure 4 In the overvoltage protection circuit shown, the power supply voltage V0 provided by the live wire L of charging pile 1 is transmitted to the third diode D3 via the induced voltage output from the DC-DC unit 60. The induced voltage received by the third diode D3 is filtered by the filter capacitor C2, and then divided by the fourth resistor R4 and the fifth resistor R5 to obtain the sampling voltage V1. The sampling voltage V1 is filtered by the sixth resistor R6 and the third capacitor C3 to obtain the sampling voltage (i.e., the comparison voltage V2). The comparison voltage V2 is input to the three-way voltage regulator U71.

[0158] The three-way voltage regulator U71 outputs a first control signal to the first transistor Q1 when the sampled voltage V2 is less than or equal to the overvoltage threshold VREF, indicating that the voltage in the circuit does not exceed the normal operating voltage range VIN-nor. This turns off the first transistor Q1, stopping the output of the conduction control signal to the control terminal of the second transistor Q2. The second transistor Q2 is turned off when no conduction control signal is received, disconnecting the enable output terminal EN-out and the ground terminal GND2, so that the enable output terminal EN-out outputs the valid enable signal EN provided by the first power supply terminal VCC1. The auxiliary power supply unit 30 supplies power to the main controller 10 when the valid enable signal EN is received. The main controller 10 controls the relay 20 to connect the charging power supply terminal L / N and the vehicle power supply terminal Lout-Nout to supply power to the vehicle.

[0159] The three-way voltage regulator U71 is also used to output a second control signal to the first transistor Q1 when the sampled voltage V2 is greater than the overvoltage threshold VREF, indicating that the voltage in the circuit exceeds the normal operating voltage range VIN-nor. This causes the second transistor Q1 to conduct, thereby outputting a conduction control signal to the control terminal of the second transistor Q2. The second transistor Q2 is used to conduct under the control of the conduction control signal to connect the enable output terminal EN-out and the ground terminal GND2, thereby pulling the enable output terminal EN-out low and outputting an invalid enable signal EN. The auxiliary power supply unit 30 is used to stop supplying power to the main controller 10 when it receives the invalid enable signal EN. The main controller 10 controls the relay 20 to disconnect the charging power terminal L / N and the vehicle power supply terminal Lout-Nout to stop supplying power to the vehicle.

[0160] Another example, such as Figure 5 As shown, the overvoltage protection circuit 40 includes a voltage sampling unit 401 and an enable control unit 402.

[0161] The voltage sampling unit 401 can multiplex the filtering and rectification units in the DC-DC unit 60 to receive the supply voltage V0 provided by the live wire, and sequentially filter and rectify the supply voltage V0 to generate a sampling signal V1 as a DC pulse signal, which is then output to the enable control unit 402. It should be noted that since the voltage sampling unit 401 multiplexes the filtering and rectification units in the DC-DC unit 60, therefore... Figure 5 The voltage sampling unit 401 is not shown.

[0162] The comparator module 4021 in the enable control unit 402 is the comparator module 4021 in the third case, specifically including: Zener diode ZD91, first resistor R1, second resistor R2, first capacitor C1, and third resistor R3. The enable configuration module 4022 in the enable control unit 402 is the enable configuration module 4022 in the second case, specifically including: optocoupler U51.

[0163] The cathode of Zener diode ZD91 is connected to voltage sampling unit 401, and the anode of Zener diode ZD91 is connected to the first terminal of first resistor R1. The second terminal of first resistor R1 is grounded through second resistor R2. Furthermore, the second terminal of first resistor R1 is also connected to the anode of light-emitting diode in optocoupler U51 through third resistor R3, and the cathode of light-emitting diode is grounded. One end of first capacitor C1 is connected to the path between first resistor R1 and third resistor R3, and the other end of first capacitor C1 is grounded. One end of phototransistor in optocoupler U51 is connected to enable output terminal EN-out, and the other end of phototransistor is connected to ground terminal GND2.

[0164] exist Figure 5In the overvoltage protection circuit shown, the power supply voltage V0 provided by the live wire terminal L of the charging pile 1 is transmitted to the Zener diode ZD91 via the sampling voltage V1 (i.e., the comparison voltage V2) output by the voltage sampling unit 401.

[0165] Zener diode ZD91 is used to enter the cutoff state when the sampled voltage V1 is less than or equal to the overvoltage threshold VREF, indicating that the voltage in the circuit does not exceed the normal operating voltage range VIN-nor. At this time, the anode of Zener diode ZD91 provides a lower voltage first control signal. The first control signal is divided by the first resistor R1 and the second resistor R2 to obtain a voltage-divided first control signal. The voltage-divided first control signal is filtered by the first capacitor C1 and the third resistor R3 to obtain a filtered first control signal. The first control signal is input to the anode of the light-emitting diode in optocoupler U51. The light-emitting diode of optocoupler U51 is used to stop working under the control of the first control signal, so that the phototransistor will not conduct due to receiving the light emitted by the light-emitting diode, thereby disconnecting the enable output terminal EN-out and the ground terminal GND2. At this time, the enable output terminal EN-out outputs the valid enable signal EN provided by the first power supply terminal VCC1. The auxiliary power supply unit 30 is used to supply power to the main controller 10 when the valid enable signal EN is received. The main controller 10 controls the relay 20 to connect the charging power supply terminal L / N and the vehicle power supply terminal Lout-Nout, thereby supplying power to the vehicle.

[0166] The Zener diode ZD91 is used to enter a breakdown state when the sampled voltage V1 exceeds the overvoltage threshold VREF, indicating that the voltage in the circuit exceeds the normal operating voltage range VIN-nor. The anode of the Zener diode ZD91 provides a higher voltage second control signal. This second control signal is divided by the first resistor R1 and the second resistor R2 to obtain a voltage-divided second control signal. This voltage-divided second control signal is then filtered by the first capacitor C1 and the third resistor R3 to obtain a filtered second control signal. This second control signal is then input to the anode of the light-emitting diode in the optocoupler U51.

[0167] The LED in optocoupler U51 operates under the control of the second control signal, allowing the phototransistor to receive the light emitted by the LED and thus conduct, connecting the enable output terminal EN-out and the ground terminal GND2. At this time, the enable output terminal EN-out is pulled low, outputting an invalid enable signal EN. The auxiliary power supply unit 30 stops supplying power to the main controller 10 upon receiving the invalid enable signal EN. The main controller 10 controls relay 20 to disconnect the charging power terminal L / N and the vehicle power supply terminal Lout-Nout to stop supplying power to the vehicle.

[0168] Another example, such as Figure 6As shown, the overvoltage protection circuit 40 includes a voltage sampling unit 401 and an enable control unit 402.

[0169] The voltage sampling unit 401 is the voltage sampling unit 401 in the second case, specifically including: a first diode D1, a second diode D2, a tenth resistor R10, an eleventh resistor R11, a twelfth resistor R12, and a fourth capacitor C4. The comparator module 4021 in the enable control unit 402 is the comparator module 4021 in the second case, specifically including: a Zener diode ZD81. The enable configuration module 4022 in the enable control unit 402 is the enable configuration module 4022 in the third case, specifically including: an optocoupler U61, a third transistor Q3, and a thirteenth resistor R13.

[0170] The first diode D1 is connected to the neutral terminal N and the target node O1. The second diode D2 is connected to the live terminal L and the target node O1. The target node O1 is grounded sequentially through the tenth resistor R10 and the eleventh resistor R11. The first end of the twelfth resistor R12 is connected to the path between the tenth resistor R10 and the eleventh resistor R11, and the second end of the twelfth resistor R12 is connected to the cathode of the Zener diode ZD81. One end of the fourth capacitor C4 is connected to the path between the tenth resistor R10 and the twelfth resistor R12, and the other end of the fourth capacitor C4 is grounded. The cathode of the Zener diode ZD81 is connected to the control terminal of the third transistor Q3. The output terminal of the third transistor Q3 is grounded, and the input terminal of the third transistor Q3 is connected to the cathode of the light-emitting diode in the optocoupler U61. The anode of the light-emitting diode is connected to the third power supply terminal VCC3 through the thirteenth resistor R13. One end of the phototransistor in the optocoupler U61 is connected to the enable output terminal EN-out, and the other end of the phototransistor is connected to the ground terminal GND2. The control unit 40223 is connected to the comparator module 4021 and the light-emitting diode.

[0171] exist Figure 6 In the overvoltage protection circuit shown, the power supply voltage V0 provided by the live wire L of charging pile 1 is directly transmitted to the first diode D1, and the power supply voltage V0 provided by the neutral wire N is directly transmitted to the second diode D2, thereby generating and outputting a rectified voltage through the target node O1. The rectified voltage is divided by the tenth resistor R10 and the eleventh resistor R11 to obtain the sampling voltage V1 (i.e., the comparison voltage V2). The sampling voltage V1 is filtered by the twelfth resistor R12 and the fourth capacitor C4 to obtain the filtered sampling voltage V1. The filtered sampling voltage V1 is input to the Zener diode ZD81.

[0172] Zener diode ZD81 is used to enter the cutoff state when the sampled voltage V1 is less than or equal to the overvoltage threshold VREF, indicating that the voltage in the circuit does not exceed the normal operating voltage range VIN-nor. At this time, the anode of Zener diode ZD91 provides a first control signal with a lower voltage to the third transistor Q3. The third transistor Q3 is used to turn off under the control of the first control signal to disconnect the third power supply terminal VCC3 and the light-emitting diode. One end of the light-emitting diode stops working because it does not receive voltage, realizing the control of the light-emitting diode to stop working, thereby disconnecting the enable output terminal EN-out and the ground terminal GND2. At this time, the enable output terminal EN-out outputs the valid enable signal EN provided by the first power supply terminal VCC1. The auxiliary power supply unit 30 is used to supply power to the main controller 10 when the valid enable signal EN is received. The main controller 10 controls the relay 20 to connect the charging power supply terminal L / N and the vehicle power supply terminal Lout-Nout to supply power to the vehicle.

[0173] Zener diode ZD81 is used to enter a breakdown state when the sampled voltage V1 is greater than the overvoltage threshold VREF, indicating that the voltage in the circuit exceeds the normal operating voltage range VIN-nor. The anode of Zener diode ZD91 provides a higher voltage second control signal to the third transistor Q3. The third transistor Q3 is turned on under the control of the second control signal to connect the third power supply terminal VCC3 and the LED. One end of the LED can receive a voltage to operate, thus controlling the LED to connect the enable output terminal EN-out and the ground terminal GND2. At this time, the enable output terminal EN-out is pulled low, outputting an invalid enable signal EN. The auxiliary power supply unit 30 is used to stop supplying power to the main controller 10 when the invalid enable signal EN is received. The main controller 10 controls relay 20 to disconnect the charging power supply terminal L / N and the vehicle power supply terminal Lout-Nout to stop supplying power to the vehicle.

[0174] Furthermore, the following are... Figure 7 The timing diagram shown is for Figures 4 to 5 The overvoltage protection circuit shown will be further explained. For example... Figure 7 As shown, when the voltage V0 in the circuit does not exceed the normal operating voltage range VIN-nor, the comparison voltage V2 is less than or equal to the overvoltage threshold VREF. The enable output terminal EN-out of the overvoltage protection circuit 40 outputs a high-level valid enable signal EM. The auxiliary power supply unit 30 supplies power to the main controller 10, and the main controller 10 outputs a high-level third control signal V3 to the switch control unit 50, so that the switch control unit 50 can connect the relay 20 and the ground terminal GND1. After the relay 20 forms an energizing circuit, it closes, connecting the charging power supply terminal L / N of the charging pile 1 and the vehicle power supply terminal Lout-Nout. The vehicle power supply terminal Lout-Nout outputs the vehicle-end power supply voltage V4 to the vehicle.

[0175] When the voltage V0 in the circuit exceeds the normal operating voltage range VIN-nor, the comparison voltage V2 is greater than the overvoltage threshold VREF. The enable output terminal EN-out of the overvoltage protection circuit 40 outputs a low-level invalid enable signal EM. The auxiliary power supply unit 30 stops supplying power to the main controller 10, and the main controller 10 stops outputting a high-level third control signal V3 to the switch control unit 50. At this time, the switch control unit 50 can be considered to have received a low-level signal V3. The switch control unit 50 is used to disconnect the relay 20 and the ground terminal GND1. The relay 20 cannot form a power-on circuit, disconnecting the charging power terminal L / N of the charging pile 1 and the vehicle power supply terminal Lout-Nout. The vehicle power supply terminal Lout-Nout stops outputting the vehicle-end power supply voltage V4 to the vehicle.

[0176] Please refer to some embodiments of this application. Figure 8 The charging pile 1 also includes a grounding detection unit 70, an input current detection unit 80, a leakage current detection unit 90, and other processing units 100. The grounding detection unit 70 is connected to the ground wire PE of the charging power supply terminal L / H and the main control unit 10, and is used to detect whether the grounding wire connected to the ground wire PE in the charging pile 1 is normal. The input current detection unit 80 is connected to the live wire L of the charging power supply terminal L / H and the main control unit 10, and is used to detect whether the grounding wire connected to the live wire L in the charging pile 1 is normal. The leakage current detection unit 90 is connected to the neutral wire N of the charging power supply terminal L / H and the main control unit 10, and is used to detect whether the grounding wire connected to the neutral wire N in the charging pile 1 is normal. The other processing units 100 are connected to the DC-DC unit 60, as well as the live wire L and the neutral wire N, and are used to preprocess the supply voltage provided by the live wire L and the neutral wire N, generating and outputting the preprocessed voltage to the DC-DC unit 60. Preprocessing includes, but is not limited to, surge protection processing, EMC filtering processing, and rectification processing.

[0177] In summary, the overvoltage protection circuit applied to the charging pile in this embodiment may include a voltage sampling unit and an enable control unit. The voltage sampling unit is used to collect the sampling voltage of the charging power supply terminal of the charging pile. The enable control unit is used to control the auxiliary power supply unit of the charging pile to connect the charging power supply terminal of the charging pile and the vehicle power supply terminal when the sampling voltage is less than or equal to the overvoltage threshold. Furthermore, the enable control unit is also used to control the auxiliary power supply unit to disconnect the charging power supply terminal of the charging pile and the vehicle power supply terminal when the sampling voltage is greater than the overvoltage threshold.

[0178] In this technical solution, the overvoltage protection circuit can determine whether the sampling voltage of the charging pile is greater than the overvoltage threshold. If the sampling voltage exceeds the overvoltage threshold, indicating that the voltage in the circuit exceeds the normal operating voltage range, the circuit controls the auxiliary power supply unit to disconnect the charging power supply terminal of the charging pile and the vehicle power supply terminal, thus achieving overvoltage protection. This prevents circuit malfunction or even damage caused by the voltage exceeding the normal operating voltage range, effectively ensuring the charging safety of the vehicle. Furthermore, since the overvoltage protection circuit in this application can directly control the existing auxiliary power supply unit of the charging pile to disconnect the charging power supply terminal and the vehicle power supply terminal, this solution, compared to the related technology that adds an overvoltage protection circuit at the vehicle end to disconnect the voltage loop between the charging circuit and the charging pile, effectively reduces the number of devices used to disconnect the voltage loop, thereby reducing the circuit complexity of the overvoltage protection circuit at the vehicle end, and consequently reducing circuit losses and costs.

[0179] Furthermore, by directly cutting off the power supply to the main controller, the relay loses its drive signal and disconnects the charging power supply from the vehicle power supply, thus directly and effectively achieving circuit protection. Compared to using the overcurrent protection program set in the main controller to execute circuit overcurrent protection, this effectively eliminates the problem of circuit overcurrent protection failure caused by program failure, effectively ensuring the execution timeliness of circuit overcurrent protection and improving the charging safety of the vehicle.

[0180] In the above embodiments, implementation can be achieved entirely or partially through software, hardware, firmware, or any combination thereof. When implemented using software, it can be implemented entirely or partially in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of this application are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that integrates one or more available media. The available medium can be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium (e.g., solid state disk (SSD)).

[0181] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0182] The various embodiments in this specification are described in a related manner. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. For embodiments of devices, electronic devices, computer-readable storage media, and computer program products containing instructions, the descriptions are relatively simple because they are basically similar to the method embodiments; relevant parts can be referred to the descriptions of the method embodiments.

[0183] The above description is merely a preferred embodiment of this application and is not intended to limit the scope of protection of this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application are included within the scope of protection of this application.

Claims

1. An overvoltage protection circuit, characterized in that, Applied to charging piles, the overvoltage protection circuit includes: a voltage sampling unit and an enable control unit; The voltage sampling unit is connected to the charging power supply terminal of the charging pile and the enabling control unit, and is used to collect the sampling voltage of the charging power supply terminal and output the sampling voltage to the enabling control unit. The enabling control unit is connected to the auxiliary power supply unit of the charging pile. When the sampled voltage is less than or equal to the overvoltage threshold, the auxiliary power supply unit is controlled to connect the charging power supply terminal and the vehicle power supply terminal of the charging pile. When the sampled voltage is greater than the overvoltage threshold, the auxiliary power supply unit is controlled to disconnect the charging power supply terminal and the vehicle power supply terminal of the charging pile.

2. The overvoltage protection circuit according to claim 1, characterized in that, The auxiliary power supply unit is used to control the connection between the charging power supply terminal and the vehicle power supply terminal under the control of a valid enable signal, and to control the disconnection between the charging power supply terminal and the vehicle power supply terminal under the control of an invalid enable signal. The enabling control unit includes: a comparison module and an enabling configuration module; The comparison module is connected to the voltage sampling unit and the enable configuration module, and is used to control the enable configuration module to output the valid enable signal to the auxiliary power supply unit when the sampled voltage is less than or equal to the overvoltage threshold; and to control the enable configuration module to output the invalid enable signal to the auxiliary power supply unit when the sampled voltage is greater than the overvoltage threshold.

3. The overvoltage protection circuit according to claim 2, characterized in that, The comparison module is used to provide a first control signal to the enable configuration module when the sampled voltage is less than or equal to the overvoltage threshold, and to provide a second control signal to the enable configuration module when the sampled voltage is greater than the overvoltage threshold. The enable configuration module is also connected to the enable output terminal and the ground terminal of the enable control unit. The enable output terminal is connected to the auxiliary power supply unit and the first power supply terminal, and the ground terminal is grounded. The enable configuration module is used to disconnect the enable output terminal and the ground terminal under the control of the first control signal, and to connect the enable output terminal and the ground terminal under the control of the second control signal.

4. The overvoltage protection circuit according to claim 3, characterized in that, The enabling configuration module includes: a first switch and a second switch; The first switch is connected to the comparison module, the second power supply terminal and the second switch, and is used to disconnect the second power supply terminal and the second switch under the control of the first control signal, and connect the second power supply terminal and the second switch under the control of the second control signal, so as to output the conduction control signal provided by the second power supply terminal to the second switch. The second switch is connected to the enable output terminal and the ground terminal, and is used to connect the enable output terminal and the ground terminal under the control of the conduction control signal.

5. The overvoltage protection circuit according to claim 4, characterized in that, The first switching element is a first transistor, and the second switching element is a second transistor; The control terminal of the first transistor is connected to the comparator module, the input terminal of the first transistor is connected to the second power supply terminal, the output terminal of the first transistor is connected to the control terminal of the second transistor, the input terminal of the second transistor is connected to the enable output terminal, and the output terminal of the second transistor is connected to the ground terminal. The first transistor is used to turn off under the control of the first control signal and turn on under the control of the second control signal, so as to output the turn-on voltage signal provided by the second power supply terminal to the second transistor; The second transistor is turned on under the control of the on-voltage signal to connect the enable output terminal and the ground terminal.

6. The overvoltage protection circuit according to claim 3, characterized in that, The enabling configuration module includes: an optocoupler; The optocoupler is connected to the comparator module, the enable output terminal, and the ground terminal, and is used to disconnect the enable output terminal and the ground terminal under the control of the first control signal, and to connect the enable output terminal and the ground terminal under the control of the second control signal.

7. The overvoltage protection circuit according to claim 6, characterized in that, The optocoupler includes a light-emitting diode and a phototransistor, one end of the phototransistor is connected to the enable output terminal, and the other end of the phototransistor is connected to the ground terminal; the enable configuration module further includes a control element. The control unit is connected to the comparison module and the light-emitting diode (LED), and is used to control the LED to stop working under the control of the first control signal to disconnect the enable output terminal and the ground terminal, and to control the LED to work under the control of the second control signal to connect the enable output terminal and the ground terminal.

8. The overvoltage protection circuit according to claim 7, characterized in that, The control component includes: a third switching component; The third switch is connected to the comparison module, the third power supply terminal, and one end of the light-emitting diode (LED). The other end of the LED is connected to the fourth power supply terminal. The third switch is used to disconnect the third power supply terminal and the optocoupler under the control of the first control signal to control the LED to stop working, and to connect the third power supply terminal and the optocoupler under the control of the second control signal to control the LED to work.

9. The overvoltage protection circuit according to claim 8, characterized in that, The third switching element is a third transistor; The control terminal of the third transistor is connected to the comparison module, the input terminal of the third transistor is connected to one end of the light-emitting diode, and the output terminal of the third transistor is connected to the third power supply terminal, for use in turning off under the control of the first control signal and turning on under the control of the second control signal.

10. The overvoltage protection circuit according to claim 2, characterized in that, The comparison module includes: a three-way voltage regulator; The input terminal of the three-way voltage regulator is connected to the voltage sampling unit, and the output terminal of the three-way voltage regulator is connected to the enable configuration module. The three-way voltage regulator is used to control the enable configuration module to output the valid enable signal when the sampled voltage is less than or equal to the overvoltage threshold, and to control the enable configuration module to output the invalid enable signal when the sampled voltage is greater than the overvoltage threshold.

11. The overvoltage protection circuit according to claim 2, characterized in that, The comparison module includes: a Zener diode, wherein the overvoltage threshold is the breakdown voltage threshold of the Zener diode; One end of the Zener diode is connected to the voltage sampling unit, and the other end of the Zener diode is connected to the enable configuration module. The Zener diode is used to control the enable configuration module to output the valid enable signal when the sampled voltage is less than or equal to the overvoltage threshold, and to control the enable configuration module to output the invalid enable signal when the sampled voltage is greater than the overvoltage threshold.

12. The overvoltage protection circuit according to claim 11, characterized in that, The Zener diode is used to provide a first control signal when the sampled voltage is less than or equal to an overvoltage threshold, and to provide a second control signal when the sampled voltage is greater than the overvoltage threshold; The comparison module further includes: a voltage divider; The voltage divider is connected to the Zener diode and the enable configuration module, and is used to perform voltage division processing on the signal provided by the Zener diode and output the divided signal to the enable configuration module.

13. The overvoltage protection circuit according to claim 12, characterized in that, The comparison module further includes: a filter; The filter is connected to the voltage divider and the enable configuration module, and is used to filter the signal provided by the voltage divider and output the filtered signal to the enable configuration module.

14. The overvoltage protection circuit according to claim 1, characterized in that, The voltage sampling unit includes: a rectifier module and a voltage divider module; The rectifier module is connected to the charging power supply terminal and the voltage divider module, and is used to rectify the supply voltage of the charging power supply terminal and output the rectified voltage to the voltage divider module. The voltage divider module is connected to the enable control unit and is used to divide the rectified voltage to generate and output the sampled voltage to the enable control unit.

15. The overvoltage protection circuit according to claim 14, characterized in that, The charging pile is an AC charging pile. The rectifier module is directly connected to the neutral and live wires of the charging power supply. It is used to rectify the supply voltage of the neutral wire and the supply voltage of the live wire, and generate and output the rectified voltage to the voltage divider module.

16. The overvoltage protection circuit according to claim 15, characterized in that, The rectifier module includes a first diode and a second diode; The first diode is connected to the neutral wire terminal and the target node, the second diode is connected to the live wire terminal and the target node, and the target node is connected to the voltage divider module; The rectifier module is used to rectify the power supply voltage of the live wire terminal through the first diode and to rectify the power supply voltage of the neutral wire terminal through the second diode, so as to output the rectified voltage to the voltage divider module through the target node.

17. The overvoltage protection circuit according to claim 14, characterized in that, The charging pile is an AC charging pile, and the charging pile also includes a DC-DC unit. The DC-DC unit is connected to the auxiliary power supply unit, the neutral wire terminal and the live wire terminal of the charging power supply terminal, and is used to convert the power supply voltage provided by the charging power supply terminal into a DC power supply voltage and supply power to the auxiliary power supply unit. The rectifier module is connected to the live wire output terminal of the DC-DC unit and is used to rectify the voltage after the power supply voltage at the live wire terminal is processed by the DC-DC unit, generate and output the rectified voltage to the voltage divider module.

18. The overvoltage protection circuit according to claim 17, characterized in that, The rectifier module includes: a third diode; The third diode is connected to the live wire output terminal and the voltage divider module, and is used to rectify the voltage after the power supply voltage of the live wire terminal is processed by the DC-DC unit, and generate and output the rectified voltage to the voltage divider module.

19. A charging pile, characterized in that, include: The main controller, relays, auxiliary power supply unit, and overvoltage protection circuit as described in any one of claims 1 to 18; The main controller is connected to the relay and the auxiliary power supply unit. The relay is used to connect the charging power supply terminal of the charging pile and the vehicle power supply terminal under the control of the main controller when it is in the energized state. The auxiliary power supply unit is used to supply power to the main controller when a valid enable signal is received, and to stop supplying power to the main controller when an invalid enable signal is received. The overvoltage protection circuit is connected to the charging power supply terminal and is used to collect the sampling voltage of the power supply voltage of the charging power supply terminal. When the sampling voltage is less than or equal to the overvoltage threshold, the circuit outputs the valid enable signal to the auxiliary power supply unit. When the sampling voltage is greater than the overvoltage threshold, the circuit outputs the invalid enable signal to the auxiliary power supply unit.

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