An alternating current charging pile control guide signal driving circuit and alternating current charging pile

Abstract

The application is suitable for the electric vehicle charging technical field, and provides a control guide signal driving circuit of an alternating current charging pile and the alternating current charging pile. The method comprises a signal control circuit, a signal interface circuit and a signal sampling circuit. The signal control circuit is connected with a controller of the alternating current charging pile, is used for driving the signal interface circuit according to a pulse width modulation signal generated by the controller; the signal interface circuit is connected with the signal control circuit, is used for carrying out filtering processing on the pulse width modulation signal, obtaining a control guide signal, and sending the control guide signal to a target vehicle; the signal sampling circuit is connected with the signal control circuit and the signal interface circuit, is used for collecting a voltage amplitude in the control guide signal, and sending the voltage amplitude to the controller of the alternating current charging pile, so that the controller of the alternating current charging pile judges a connection state of the alternating current charging pile and the target vehicle and a charging state of the target vehicle according to the voltage amplitude, and the charging safety and reliability of the system can be improved.

Description

Technical Field

[0001] This application belongs to the field of electric vehicle charging technology, and in particular relates to a control and guidance signal drive circuit for an AC charging pile and an AC charging pile. Background Technology

[0002] With the rapid popularization of electric vehicles, AC charging piles, as core infrastructure, need to meet the requirements of high compatibility, high stability, and intelligence. The control guidance signal drive circuit (CP drive circuit) is the core module for communication, status detection, and safety control between electric vehicles and AC charging piles. The CP signal is mainly used to monitor the interaction between the electric vehicle and the AC charging pile power supply equipment (charging pile). It is the only communication signal between the electric vehicle and the charging pile, achieving "handshake" communication between them through pulse width modulation (PWM) signal modulation and amplitude alternation. The role of the CP drive circuit is crucial throughout the entire charging process, and its performance directly determines the safety, efficiency, and user experience of charging.

[0003] However, in the existing technology, the CP drive circuit uses a push-pull output method to output the PWM signal waveform. This output method is non-isolated and has unreliable factors, which affects the safety and reliability of the charging process. Summary of the Invention

[0004] This application provides a control guidance signal driving circuit for an AC charging pile and an AC charging pile, which can solve the technical problems of poor charging safety and reliability caused by the non-isolated output of pulse width modulation waveforms by the existing control guidance signal driving circuits for AC charging piles.

[0005] In a first aspect, embodiments of this application provide a control guidance signal driving circuit for an AC charging pile, the circuit comprising: The circuit consists of a signal control circuit, a signal interface circuit, and a signal sampling circuit. The signal control circuit is connected to the controller of the AC charging pile and is used to drive the signal interface circuit according to the pulse width modulation signal generated by the controller. The signal interface circuit is connected to the signal control circuit and is used to filter the pulse width modulation signal to obtain a control guidance signal, and send the control guidance signal to the target vehicle; wherein, the control guidance signal represents the connection status between the AC charging pile and the target vehicle and the charging status of the target vehicle during the charging process through voltage amplitude; The signal sampling circuit, connected to the signal control circuit and the signal interface circuit, is used to collect the voltage amplitude in the control guidance signal and send the voltage amplitude to the controller of the AC charging pile, so that the controller of the AC charging pile can determine the connection status between the AC charging pile and the target vehicle and the charging status of the target vehicle based on the voltage amplitude.

[0006] In one possible implementation of the first aspect, the signal control circuit includes: a transistor circuit, an optocoupler, a first resistor, a second resistor, a voltage divider circuit, and a circuit power supply; wherein, The input terminal of the transistor circuit is connected to the controller of the AC charging pile, and the output terminal of the transistor circuit is connected to the input terminal of the first resistor and the first input terminal of the optocoupler, respectively. The second input terminal of the optocoupler is connected to the output terminal of the first resistor, the first resistor is connected to the power supply of the circuit via the second resistor, the output terminal of the optocoupler is connected to the input terminal of the voltage divider circuit, and the output terminal of the voltage divider circuit is connected to the input terminal of the signal interface circuit. The circuit power supply provides power to the optocoupler.

[0007] In one possible implementation of the first aspect, the transistor circuit includes: a third resistor, a fourth resistor, and a transistor; wherein, The input terminal of the third resistor is connected to the first signal port of the controller of the AC charging pile, the output terminal of the third resistor is connected to the input terminal of the fourth resistor and the base terminal of the transistor, and the collector terminal of the transistor is connected to the first input terminal of the optocoupler. The output terminal of the fourth resistor and the emitter terminal of the transistor are grounded.

[0008] In one possible implementation of the first aspect, the voltage divider circuit includes: a first voltage divider resistor, a second voltage divider resistor, a third voltage divider resistor, a fifth resistor, a sixth resistor, a first filter circuit, and a second filter circuit; wherein, The output terminal of the optocoupler is connected to the input terminal of the fifth resistor and the input terminal of the first voltage divider resistor, respectively, and the output terminal of the fifth resistor is grounded. The output terminal of the first voltage divider resistor is connected to the input terminal of the second voltage divider resistor and the input terminal of the first filter circuit, respectively. The output terminal of the first filter circuit is grounded. The first filter circuit includes a first filter resistor and a first capacitor. The output terminal of the second voltage divider resistor is connected to the input terminal of the third voltage divider resistor and the input terminal of the second filter circuit, respectively. The output terminal of the second filter circuit is grounded. The second filter circuit includes a second filter resistor and a second capacitor. The output terminal of the third voltage divider resistor is connected to the input terminal of the sixth resistor, and the output terminal of the sixth resistor is connected to the input terminal of the signal interface circuit and the input terminal of the signal sampling circuit.

[0009] In one possible implementation of the first aspect, the signal interface circuit includes: a third filter circuit, a transient voltage suppression diode, and a thermistor, wherein, The input terminal of the third filter circuit is connected to the output terminal of the signal control circuit, and the output terminal of the third filter circuit is connected to the input terminal of the transient voltage suppression diode and the input terminal of the thermistor, respectively, for filtering high-frequency ripple in the pulse width modulation signal. The output terminal of the transient voltage suppression diode is grounded, and the output terminal of the thermistor is connected to the interface resistor of the target vehicle. The third filter circuit includes a first wire-wound inductor, a second wire-wound inductor, a third capacitor, and a fourth capacitor, wherein... The input terminal of the first wire-wound inductor is connected to the input terminal of the third capacitor, and the output terminal of the first wire-wound inductor is connected to the input terminal of the fourth capacitor and the input terminal of the second wire-wound inductor, respectively. The output terminals of the third capacitor and the fourth capacitor are grounded. The output terminal of the second wire-wound inductor is connected to the input terminal of the transient voltage suppression diode and the input terminal of the thermistor, respectively.

[0010] In one possible implementation of the first aspect, the signal sampling circuit includes: a dual operational amplifier circuit, a clamping diode, and a circuit power supply; wherein, The input terminal of the dual operational amplifier circuit is connected to the output terminal of the signal control circuit; The output terminal of the dual operational amplifier circuit is connected to the input terminal of the clamping diode; The first output terminal of the clamping diode is connected to the second signal port of the controller of the AC charging pile; The input terminal of the clamping diode is connected to the power supply of the circuit, and the second output terminal of the clamping diode is grounded.

[0011] In one possible implementation of the first aspect, the dual-channel operational amplifier circuit includes: a first-stage operational amplifier circuit, a second-stage operational amplifier circuit, a first sampling resistor, a second sampling resistor, a first sampling capacitor, and a second sampling capacitor; wherein, The first input terminal of the first-stage operational amplifier circuit is connected to the output terminal of the signal control circuit, and the second input terminal of the first-stage operational amplifier circuit is grounded. The output terminal of the first-stage operational amplifier circuit is connected to the input terminal of the first sampling resistor, the output terminal of the first sampling resistor is connected to the first input terminal of the second-stage operational amplifier circuit and the input terminal of the first sampling capacitor, and the output terminal of the first sampling capacitor is grounded. The output terminal of the second-stage operational amplifier circuit is connected to the input terminal of the second sampling resistor, and the output terminal of the second sampling resistor is connected to the input terminal of the second sampling capacitor and the first output terminal of the clamping diode.

[0012] In one possible implementation of the first aspect, the first-stage operational amplifier circuit includes: a first operational amplifier, a first feedback resistor, a second feedback resistor, a third amplification resistor, a first compensation capacitor, and a first filter capacitor; wherein, The input terminal of the first feedback resistor is connected to the output terminal of the signal control circuit, the output terminal of the first feedback resistor is connected to the negative input terminal of the first operational amplifier, and the second feedback resistor and the first compensation capacitor are connected in parallel to form a first parallel circuit. The input terminal of the first parallel circuit is connected to the negative input terminal of the first operational amplifier, and the output terminal of the first parallel circuit is connected to the output terminal of the first operational amplifier. The third amplifying resistor and the first filtering capacitor form a second parallel circuit. The output terminal of the second parallel circuit is grounded, and the input terminal of the second parallel circuit is connected to the positive input terminal of the first operational amplifier. The output terminal of the first operational amplifier is connected to the input terminal of the first sampling resistor.

[0013] In one possible implementation of the first aspect, the second-stage operational amplifier circuit includes: a second operational amplifier, a fourth feedback resistor, a fifth feedback resistor, a sixth amplification resistor, a seventh amplification resistor, a second compensation capacitor, and a second filter capacitor; wherein, The input terminal of the fourth feedback resistor is connected to the output terminal of the first sampling resistor, the output terminal of the fourth feedback resistor is connected to the negative input terminal of the second operational amplifier, and the fifth feedback resistor and the second compensation capacitor are connected in parallel to form a third parallel circuit. The input terminal of the third parallel circuit is connected to the negative input terminal of the second operational amplifier, and the output terminal of the third parallel circuit is connected to the output terminal of the second operational amplifier. The sixth amplifying resistor and the second filtering capacitor form a fourth parallel circuit. The output terminal of the fourth parallel circuit is grounded, and the input terminal of the fourth parallel circuit is connected to the positive input terminal of the second operational amplifier. The power supply of the circuit is connected to the positive input terminal of the second operational amplifier through the seventh amplifying resistor. The output terminal of the second operational amplifier is connected to the input terminal of the second sampling resistor.

[0014] Secondly, embodiments of this application provide an AC charging pile, including: a controller and a control guidance signal driving circuit for the AC charging pile as described in any one of the first aspects above, wherein the controller is communicatively connected to the control guidance signal driving circuit.

[0015] The beneficial effects of the embodiments in this application compared with the prior art are: This application provides a control guidance signal driving circuit for an AC charging pile, including a signal control circuit, a signal interface circuit, and a signal sampling circuit. The signal control circuit is connected to the controller of the AC charging pile and drives the signal interface circuit based on a pulse width modulation (PWM) signal generated by the controller. The signal interface circuit is connected to the signal control circuit and filters the PWM signal to obtain a control guidance signal, which is then sent to the target vehicle. The control guidance signal represents the connection status between the AC charging pile and the target vehicle, as well as the charging status of the target vehicle during charging, through its voltage amplitude. The signal sampling circuit is connected to the signal control circuit and the signal interface circuit and collects the voltage amplitude from the control guidance signal. It then sends the voltage amplitude to the controller of the AC charging pile, enabling the controller to determine the connection status between the AC charging pile and the target vehicle, as well as the charging status of the target vehicle, based on the voltage amplitude. This control guidance signal driving circuit for the AC charging pile improves system stability by using the signal control circuit as isolation between the control guidance signal and the output, and reduces system interference and enhances surge protection through the signal interface circuit, thereby improving the charging safety and reliability of the system. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the structure of a control guidance signal driving circuit provided in an embodiment of this application; Figure 2This is a schematic diagram of a signal control circuit provided in one embodiment of this application; Figure 3 This is a schematic diagram of a signal interface circuit provided in one embodiment of this application; Figure 4 This is a schematic diagram of a signal sampling circuit provided in one embodiment of this application; Figure 5 This is a schematic diagram of the structure of an AC charging pile provided in one embodiment of this application. Detailed Implementation

[0018] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of this application. However, those skilled in the art will understand that this application may also be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods have been omitted so as not to obscure the description of this application with unnecessary detail.

[0019] It should be understood that, when used in this application specification and the appended claims, the term "comprising" indicates the presence of the described features, integrals, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or a collection thereof.

[0020] It should also be understood that the term “and / or” as used in this application specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0021] As used in this application specification and the appended claims, the term "if" may be interpreted, depending on the context, as "when," "once," "in response to determination," or "in response to detection." Similarly, the phrase "if determined" or "if detected [the described condition or event]" may be interpreted, depending on the context, as meaning "once determined," "in response to determination," "once detected [the described condition or event]," or "in response to detection [the described condition or event]."

[0022] Furthermore, in the description of this application and the appended claims, the terms "first," "second," "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0023] References to "one embodiment" or "some embodiments" as described in this specification mean that one or more embodiments of this application include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized.

[0024] Please see Figure 1 , Figure 1 This is a schematic diagram of the structure of a control guidance signal driving circuit for an AC charging pile according to an embodiment of this application. The control guidance signal driving circuit 1 for the AC charging pile includes: a signal control circuit 10, a signal interface circuit 20, and a signal sampling circuit 30, wherein... The signal control circuit 10 is connected to the controller 2 of the AC charging pile and is used to drive the signal interface circuit 20 according to the pulse width modulation signal generated by the controller 2. The signal interface circuit 20 is connected to the signal control circuit 10 and is used to filter the pulse width modulation signal to obtain a control guidance signal, and send the control guidance signal to the target vehicle 3; wherein, the control guidance signal represents the connection status between the AC charging pile and the target vehicle 3 and the charging status of the target vehicle 3 during the charging process through the voltage amplitude. The signal sampling circuit 30 is connected to the signal control circuit 10 and the signal interface circuit 20. It is used to collect the voltage amplitude in the control guidance signal and send the voltage amplitude to the controller 2 of the AC charging pile so that the controller 2 of the AC charging pile can determine the connection status between the AC charging pile and the target vehicle 3 and the charging status of the target vehicle 3 based on the voltage amplitude.

[0025] It should be noted that the control guidance signal drive circuit 1 of this AC charging pile is used in the AC charging pile and is a circuit module for generating, processing, and transmitting control guidance signals (CP signals). The function of the control guidance signal drive circuit 1 of this AC charging pile is to ensure that the AC charging pile can effectively communicate with the target vehicle (usually an electric vehicle), thereby realizing accurate control and status monitoring of the charging process.

[0026] The control guidance signal drive circuit 1 of the AC charging pile consists of three parts: signal control circuit 10, signal interface circuit 20, and signal sampling circuit 30. By working in conjunction with the controller 2 of the AC charging pile, it realizes the full-process control of CP signal generation, transmission, and status feedback.

[0027] The signal control circuit 10 is connected to the controller 2 of the AC charging pile, and also to the signal interface circuit 20 and the signal sampling circuit 30. The signal control circuit 10 can convert the pulse width modulation signal (PWM signal) output by the controller 2 into a level signal to drive the signal interface circuit 20, thereby driving the signal interface circuit 20. The pulse width modulation signal is a signal that transmits information by changing the pulse width. During the charging process of the AC charging pile, the controller 2 transmits different control commands to the signal control circuit 10 by adjusting the pulse width of the pulse width modulation signal. This causes the signal control circuit 10 to convert the pulse width modulation signal into a level signal to drive the signal interface circuit 20, thereby controlling the entire charging process.

[0028] The signal interface circuit 20 is connected to the signal control circuit 10 and the signal sampling circuit 30. It can filter the PWM signal to generate a CP signal that matches the target vehicle 3, and then send the CP signal to the target vehicle 3. The CP signal transmits information through voltage amplitude, which can indicate the connection status between the AC charging pile and the target vehicle 3 (such as whether it is connected) and the charging status of the target vehicle 3 during the charging process (such as whether charging has started, whether it is fully charged, etc.).

[0029] The signal sampling circuit 30 can collect the voltage amplitude in the CP signal in real time, and then feed the voltage amplitude back to the controller 2 to determine whether the AC charging pile and the target vehicle 3 have been connected, and to determine the charging status of the target vehicle 3, etc.

[0030] Specifically, during the charging process of the target vehicle, if the signal sampling circuit 30 measures a voltage of 12V, it indicates that the AC charging pile and the target vehicle 3 are not currently connected; if the signal sampling circuit 30 measures a voltage of 9V, it indicates that the AC charging pile and the target vehicle 3 are currently connected but not started; if the signal sampling circuit 30 measures a PWM waveform with a voltage of 9V, it indicates that the AC charging pile is currently in the starting state and the target vehicle 3 is not ready; if the signal sampling circuit 30 measures a PWM waveform with a voltage of 6V, it indicates that the target vehicle 3 is ready and the switch on the side of the target vehicle 3 is closed. At this time, the AC charging pile control power relay closes to start charging.

[0031] In some examples, such as Figure 2 As shown, Figure 2 This is a schematic diagram of a signal control circuit according to an embodiment of this application. Figure 2The signal control circuit 10 includes: a transistor circuit 101, an optocoupler U, a first resistor R11, a second resistor R12, a voltage divider circuit 102, and a circuit power supply 103. The input terminal of the transistor circuit 101 is connected to the controller 2 of the AC charging pile. The output terminal of the transistor circuit 101 is connected to the input terminal of the first resistor R11 and the first input terminal U1 of the optocoupler U. The second input terminal U2 of the optocoupler U is connected to the output terminal of the first resistor R11. The first resistor R11 is connected to the circuit power supply 103 via the second resistor R12. The output terminal U3 of the optocoupler U is connected to the input terminal of the voltage divider circuit 102, and the output terminal of the voltage divider circuit 102 is connected to the input terminal of the signal interface circuit 20. The circuit power supply 103 provides power to the optocoupler U.

[0032] It should be noted that the signal control circuit 10 can realize the level conversion of the PWM signal output by the controller of the AC charging pile and enhance its driving capability.

[0033] In this embodiment, transistor circuit 101 is used for signal amplification and level conversion. The input terminal of optocoupler U is controlled by transistor circuit 101 to switch on and off, and the output terminal transmits the PWM signal to voltage divider circuit 102, which can achieve electrical isolation and prevent high-voltage interference between the AC charging pile controller 2 and subsequent circuits. The first resistor R11 is a current-limiting resistor. The second resistor R12 is a pull-up resistor to ensure the voltage stability of the optocoupler and avoid false triggering caused by floating input. Voltage divider circuit 102 is used to adjust the output voltage of optocoupler U to the level required by signal interface circuit 20. Circuit power supply 103 supplies power to the input terminal of optocoupler U, such as 3.3V. The PWM signal generated by the controller drives optocoupler U through transistor circuit 101, and optocoupler U outputs ±12V voltage, which achieves isolation of signal interface circuit 20. Figure 2 As shown, the ±12V voltage output by optocoupler U needs to be filtered by two capacitors C71 and C72 to obtain a more stable voltage signal.

[0034] like Figure 2 As shown, the first signal port of the controller 2 of the AC charging pile is the port for generating PWM signals, used to output PWM signals, that is... Figure 2 The A-CP-PWM port. The A-CP-1 port represents the signal output port of the signal control circuit 10.

[0035] It should be understood that introducing an optocoupler into the signal control circuit serves as isolation between the CP signal and the output, avoiding interference and improving system stability.

[0036] In some examples, such as Figure 2In the circuit, transistor circuit 101 includes a third resistor R13, a fourth resistor R14, and a transistor Q. The input terminal of the third resistor R13 is connected to the first signal port of the controller 2 of the AC charging pile. The output terminal of the third resistor R13 is connected to the input terminal of the fourth resistor R14 and the base terminal Q1 of the transistor Q. The collector terminal Q2 of the transistor Q is connected to the first input terminal U1 of the optocoupler U. The output terminal of the fourth resistor R14 and the emitter terminal Q3 of the transistor Q are grounded.

[0037] In this embodiment, the transistor circuit 101 consists of a third resistor R13, a fourth resistor R14, and a transistor Q, forming a switch driving circuit.

[0038] After the A-CP-PWM port outputs a PWM signal, it is current-limited by the third resistor R13 and then drives the base terminal Q1 of transistor Q. When the signal is high, transistor Q is turned on, pulling the first input terminal U1 of optocoupler U low through the fourth resistor R14; when the signal is low, transistor Q is turned off, and the first input terminal U1 of optocoupler U is pulled up to the voltage of the circuit power supply 103 through the first resistor R11 and the second resistor R12. The fourth resistor R14 acts as a pull-down resistor, ensuring a stable state for transistor Q and preventing malfunctions.

[0039] In some examples, such as Figure 2 In the circuit, the voltage divider circuit 102 includes: a first voltage divider resistor R21, a second voltage divider resistor R22, a third voltage divider resistor R23, a fifth resistor R15, a sixth resistor R16, a first filter circuit, and a second filter circuit.

[0040] The output terminal U3 of the optocoupler U is connected to the input terminal of the fifth resistor R15 and the input terminal of the first voltage divider resistor R21, respectively, and the output terminal of the fifth resistor R15 is grounded.

[0041] The output of the first voltage divider resistor R21 is connected to the input of the second voltage divider resistor R22 and the input of the first filter circuit. The output of the first filter circuit is grounded. The first filter circuit includes a first filter resistor R31 and a first capacitor C31. The output of the second voltage divider resistor R22 is connected to the input of the third voltage divider resistor R23 and the input of the second filter circuit. The output of the second filter circuit is grounded. The second filter circuit includes a second filter resistor R32 and a second capacitor C32. The output of the third voltage divider resistor R23 is connected to the input of the sixth resistor R16. The output of the sixth resistor R16 is connected to the input of the signal interface circuit 20 and the input of the signal sampling circuit 30.

[0042] It should be noted that the voltage divider circuit 102 is used to adjust the voltage amplitude of the output signal of the optocoupler U to meet the input requirements of the signal interface circuit 20. In this embodiment, the voltage divider circuit 102 is equipped with multiple voltage divider resistors, such as the first voltage divider resistor R21, the second voltage divider resistor R22, and the third voltage divider resistor R23. Through these multiple voltage divider resistors, the voltage amplitude of the output signal of the optocoupler U is proportionally attenuated to the logic level required by the signal interface circuit 20. The first voltage divider resistor R21 can be a pull-up resistor to ensure that the output voltage is stable when the optocoupler U is turned off, avoiding fluctuations; the second voltage divider resistor R22 can be an intermediate voltage divider resistor to adjust the voltage attenuation slope; and the third voltage divider resistor R23 can be a critical voltage divider resistor, directly determining the output voltage amplitude.

[0043] The input terminal of the fifth resistor R15 is connected to the output terminal U3 of the optocoupler U, and the output terminal of the fifth resistor R15 is grounded, which can serve as the DC bias path for the output terminal U3 of the optocoupler to prevent the output voltage from drifting due to leakage current. At the same time, the fifth resistor R15 and the first voltage divider resistor R21 form a static voltage divider, which can ensure that the output voltage can be a fixed value when there is no signal.

[0044] The first and second filter circuits can be used to suppress high-frequency noise, eliminate signal distortion, ensure signal stability, and improve signal quality. The first and second filter circuits can be RC low-pass filters. The first filter circuit includes a first filter resistor R31 and a first capacitor C31, positioned at the junction of the first voltage divider resistor R21 and the second voltage divider resistor R22, which can filter out switching noise from the optocoupler U. The second filter circuit includes a second filter resistor R32 and a second capacitor C32, positioned at the junction of the second voltage divider resistor R22 and the third voltage divider resistor R23, which can further smooth the signal. It should be understood that by setting up two stages of filter circuits, high-frequency interference can be suppressed more effectively.

[0045] The sixth resistor R16 can be used for current limiting protection. It is connected to the output terminal (i.e., the A-CP-1 port) of the signal control circuit 10 to prevent excessive current caused by the low input impedance of the signal interface circuit 20 or the signal sampling circuit 30. It can also form a voltage divider with the input impedance of the signal interface circuit 20 or the signal sampling circuit 30 to ensure the stability of the signal amplitude.

[0046] It should be understood that the voltage divider circuit 102 achieves precise attenuation, noise suppression, and level conversion of the output signal of the optocoupler, providing a stable and reliable input signal for the subsequent signal interface circuit 20 or signal sampling circuit 30.

[0047] In one possible implementation, such as Figure 3 As shown, Figure 3 This is a schematic diagram of a signal interface circuit provided in one embodiment of this application. Figure 3 In the signal interface circuit 20, there are: a third filter circuit 105, a transient voltage suppression diode (TVS), and a thermistor (PTC).

[0048] The input terminal of the third filter circuit 105 is connected to the output terminal of the signal control circuit 10. The output terminal of the third filter circuit 105 is connected to the input terminals of the transient voltage suppressor diode (TVS) and the thermistor (PTC), respectively, to filter high-frequency ripple in the pulse width modulation signal. The output terminal of the transient voltage suppressor diode (TVS) is grounded, and the output terminal of the thermistor (PTC) is connected to the interface resistor of the target vehicle 3.

[0049] It should be noted that, Figure 3 In the signal interface circuit 20, a third filter circuit 105, a transient voltage suppressor diode (TVS), and a thermistor (PTC) are used. The TVS can clamp transient overvoltages (such as electrostatic discharge and lightning surges) in the signal interface circuit 20, protecting downstream circuits (such as vehicle interfaces) from damage. The PTC is connected to the interface resistor of the target vehicle 3. Figure 3 In the diagram, A-CP represents the port of target vehicle 3. It can be used for overcurrent protection. When the signal interface circuit 20 is short-circuited or the load is abnormal, the resistance of the thermistor PTC will increase sharply with the temperature, limiting the current to a safe range. At the same time, after the fault is cleared, the thermistor PTC cools down and returns to a low-resistance state, without the need for manual replacement. The third filter circuit 105 is connected to the output terminal (A-CP-1 port) of the signal control circuit 10. It can filter out high-frequency ripple in the CP signal, reduce signal interference, improve the stability of CP signal sampling, and also improve electromagnetic compatibility.

[0050] In some examples, such as Figure 3 As shown, the third filter circuit 105 includes a first wire-wound inductor L1, a second wire-wound inductor L2, a third capacitor C33, and a fourth capacitor C34.

[0051] The input terminal of the first wire-wound inductor L1 is connected to the input terminal of the third capacitor C33. The output terminal of the first wire-wound inductor L1 is connected to the input terminals of the fourth capacitor C34 and the second wire-wound inductor L2, respectively. The output terminals of the third capacitor C33 and the fourth capacitor C34 are grounded. The output terminal of the second wire-wound inductor L2 is connected to the input terminals of the transient voltage suppressor diode (TVS) and the thermistor (PTC), respectively.

[0052] Figure 3In this circuit, the first winding inductor L1, the third capacitor C33, and the fourth capacitor C34 form a Π-type LC filter circuit, which is then connected to the second winding inductor L2. The first winding inductor L1 presents high impedance to the high-frequency ripple in the CP signal, preventing the high-frequency signal from passing through. The second winding inductor L2 further suppresses the remaining high-frequency ripple, thereby obtaining a low-noise signal.

[0053] It should be understood that by introducing wire-wound inductors and transient voltage suppression diodes into the signal interface circuit, system interference is reduced, surge protection is improved, and system safety and reliability are enhanced.

[0054] In one possible implementation, such as Figure 4 As shown, Figure 4 This is a schematic diagram of a signal sampling circuit provided in one embodiment of this application. Figure 4 In the circuit, the signal sampling circuit 30 includes: a dual-channel operational amplifier circuit 106, a clamping diode D, and a circuit power supply 103.

[0055] The input terminal of the dual operational amplifier circuit 106 is connected to the output terminal of the signal control circuit 10. The output terminal of the dual operational amplifier circuit 106 is connected to the input terminal of the clamping diode D. The first output terminal of the clamping diode D is connected to the second signal port of the controller 2 of the AC charging pile. The input terminal of the clamping diode D is connected to the circuit power supply 103, and the second output terminal of the clamping diode D is grounded.

[0056] It should be noted that, Figure 4 In the process, the signal sampling circuit 30 can acquire the voltage amplitude in the CP signal in real time, and then feed this voltage amplitude back to the controller 2. The second signal port of the controller 2 of the AC charging pile is the signal sampling port, that is... Figure 4 The A-CP-CHECK port in the middle.

[0057] The signal sampling circuit 30 consists of a dual operational amplifier circuit 106, a clamping diode D, and a circuit power supply 103. The dual operational amplifier circuit 106 comprises two stages of operational amplifiers and is connected to the output terminal (A-CP-1 port) of the signal control circuit 10. It is used to inversely amplify the CP signal before inputting it to the A-CP-CHECK port of the controller 2. The clamping diode D is used to clamp the sampling voltage within a safe range (e.g., limiting the voltage to 0~3.3V) to prevent damage to the A-CP-CHECK port due to the input voltage exceeding the maximum input voltage. The circuit power supply 103 is connected to the input terminal of the clamping diode D, providing power to the clamping diode D.

[0058] In some examples, such as Figure 4In the middle, the dual-channel operational amplifier circuit 106 includes: a first-stage operational amplifier circuit 107, a second-stage operational amplifier circuit 108, a first sampling resistor R41, a second sampling resistor R42, a first sampling capacitor C41, and a second sampling capacitor C42.

[0059] In this circuit, the first input terminal of the first-stage operational amplifier circuit 107 is connected to the output terminal of the signal control circuit 10, and the second input terminal of the first-stage operational amplifier circuit 107 is grounded. The output terminal of the first-stage operational amplifier circuit 107 is connected to the input terminal of the first sampling resistor R41, and the output terminal of the first sampling resistor R41 is connected to the first input terminal of the second-stage operational amplifier circuit 108 and the input terminal of the first sampling capacitor C41, with the output terminal of the first sampling capacitor C41 grounded. The output terminal of the second-stage operational amplifier circuit 108 is connected to the input terminal of the second sampling resistor R42, and the output terminal of the second sampling resistor R42 is connected to the input terminal of the second sampling capacitor C42 and the first output terminal of the clamping diode D.

[0060] Figure 4 In this circuit, the dual-channel operational amplifier circuit 106 includes a first-stage operational amplifier circuit 107 and a second-stage operational amplifier circuit 108. The first-stage operational amplifier circuit 107 is an inverse proportional operational amplifier circuit with a 1:1 amplification ratio, effectively inverting the sampled signal. The second-stage operational amplifier circuit 108 amplifies the sampled signal before inputting it to the A-CP-CHECK port of the controller.

[0061] The first sampling resistor R41 is used to convert the current output by the first-stage operational amplifier circuit 107 into a voltage signal for processing by the second-stage operational amplifier circuit 108. The first sampling resistor R41 and the first sampling capacitor C41 form an RC feedback network, which can adjust the frequency response of the second-stage operational amplifier circuit 1008, attenuate high-frequency noise, and smooth the output signal. The first sampling resistor R41 isolates the two operational amplifier circuits, reducing mutual interference.

[0062] The second sampling resistor R42 converts the current output from the second-stage operational amplifier circuit 108 into a voltage signal for processing by the downstream circuitry. The second sampling resistor R42 and the second sampling capacitor C42 form an RC feedback network, which further suppresses high-frequency noise and stabilizes the output sampling signal. The second sampling resistor R42 limits the output current to prevent excessive current when the clamping diode D is conducting. The second sampling capacitor C42 filters noise in the CP signal, reducing interference with the output signal.

[0063] It should be understood that the dual-channel operational amplifier circuit 106 achieves signal directional reduction, filtering, and protection, thereby stabilizing circuit performance.

[0064] In one possible implementation, the first-stage operational amplifier circuit 107 includes: a first operational amplifier F1, a first feedback resistor R51, a second feedback resistor R52, a third amplification resistor R53, a first compensation capacitor C51, and a first filter capacitor C61.

[0065] In this circuit, the input terminal of the first feedback resistor R51 is connected to the output terminal of the signal control circuit 10, and the output terminal of the first feedback resistor R51 is connected to the negative input terminal of the first operational amplifier F1. The second feedback resistor R52 and the first compensation capacitor C51 are connected in parallel to form a first parallel circuit. The input terminal of the first parallel circuit is connected to the negative input terminal of the first operational amplifier F1, and the output terminal of the first parallel circuit is connected to the output terminal of the first operational amplifier F1. The third amplification resistor R53 and the first filter capacitor C61 form a second parallel circuit. The output terminal of the second parallel circuit is grounded, and the input terminal of the second parallel circuit is connected to the positive input terminal of the first operational amplifier F1. The output terminal of the first operational amplifier F1 is connected to the input terminal of the first sampling resistor R41.

[0066] It should be noted that in this embodiment, the first-stage operational amplifier circuit 107 is an inverse proportional operational amplifier circuit with a 1:1 amplification ratio, thus achieving the inversion of the sampled signal. For example... Figure 4 In this circuit, the first feedback resistor R51 and the second feedback resistor R52 are the feedback resistors of the first operational amplifier F1. The first compensation capacitor C51 is a compensation capacitor. The first compensation capacitor C51 and the second feedback resistor R52 form a first parallel circuit, which is connected in parallel across the negative input terminal and the output terminal of the first operational amplifier F1. The first filter capacitor C61 is used for filtering, and the third amplification resistor R53 is used for pull-down. The third amplification resistor R53 and the first filter capacitor C61 form a second parallel circuit. The input terminal of the second parallel circuit is connected to the positive input terminal of the first operational amplifier F1, and the output terminal of the second parallel circuit is grounded.

[0067] In one possible implementation, the second-stage operational amplifier circuit 108 includes: a second operational amplifier F2, a fourth feedback resistor R54, a fifth feedback resistor R55, a sixth amplification resistor R56, a seventh amplification resistor R57, a second compensation capacitor C52, and a second filter capacitor C62.

[0068] In this circuit, the input of the fourth feedback resistor R54 is connected to the output of the first sampling resistor R41, and the output of the fourth feedback resistor R54 is connected to the negative input of the second operational amplifier F2. The fifth feedback resistor R55 and the second compensation capacitor C52 are connected in parallel to form the third parallel circuit. The input of the third parallel circuit is connected to the negative input of the second operational amplifier F2, and the output of the third parallel circuit is connected to the output of the second operational amplifier F2. The sixth amplification resistor R56 and the second filter capacitor C62 form the fourth parallel circuit. The output of the fourth parallel circuit is grounded, and the input of the fourth parallel circuit is connected to the positive input of the second operational amplifier F2. The circuit power supply 103 is connected to the positive input of the second operational amplifier F2 via the seventh amplification resistor R57. The output of the second operational amplifier F2 is connected to the input of the second sampling resistor R42.

[0069] It should be noted that, as Figure 4 In this circuit, the second-stage operational amplifier circuit 108 reduces the sampled signal before inputting it to the A-CP-CHECK port of the controller. The fourth feedback resistor R54 and the fifth feedback resistor R55 are the feedback resistors for the second operational amplifier F2. The second compensation capacitor C52 is a compensation capacitor. The second compensation capacitor C52 and the fifth feedback resistor R55 form a third parallel circuit, connected in parallel across the negative input and output terminals of the second operational amplifier F2. The second filter capacitor C62 provides filtering. The sixth amplification resistor R56 and the second filter capacitor C62 form a fourth parallel circuit. The input terminal of the fourth parallel circuit is connected to the positive input terminal of the second operational amplifier F2, and the output terminal of the second parallel circuit is grounded. The circuit power supply 103 is connected to the positive input terminal of the second operational amplifier F2 via the seventh amplification resistor R57, providing voltage to the second operational amplifier F2. Among them, the sixth amplification resistor R56 and the seventh amplification resistor R57 are voltage divider resistors that provide a reference voltage to the second operational amplifier F2. After the voltage is divided by the sixth amplification resistor R56 and the seventh amplification resistor R57, it is input to the non-inverting input terminal of the second operational amplifier F2, shifting the sampling signal to a positive voltage, which facilitates signal sampling at the A-CP-CHECK port of the controller.

[0070] It should be noted that, in the embodiments of this application, the parameter range of each component is not limited, and each component can be selected according to the specific actual situation.

[0071] It should be noted that the control and guidance signal drive circuit for AC charging piles provided in this application embodiment can be applied to the CP control and guidance circuit of portable charging piles or fixed charging piles.

[0072] It is understood that this application provides a control guidance signal driving circuit for an AC charging pile, including: a signal control circuit, a signal interface circuit, and a signal sampling circuit. The signal control circuit is connected to the controller of the AC charging pile and is used to drive the signal interface circuit according to a pulse width modulation signal generated by the controller. The signal interface circuit is connected to the signal control circuit and is used to filter the pulse width modulation signal to obtain a control guidance signal, and then send the control guidance signal to the target vehicle. The control guidance signal represents the connection status between the AC charging pile and the target vehicle, as well as the charging status of the target vehicle during the charging process, through its voltage amplitude. The signal sampling circuit is connected to the signal control circuit and the signal interface circuit and is used to collect the voltage amplitude in the control guidance signal and send the voltage amplitude to the controller of the AC charging pile, so that the controller of the AC charging pile can determine the connection status between the AC charging pile and the target vehicle, as well as the charging status of the target vehicle, based on the voltage amplitude. This control guidance signal driving circuit for the AC charging pile improves system stability by using the signal control circuit as isolation between the control guidance signal and the output, and reduces system interference and enhances surge resistance through the signal interface circuit, thereby improving the charging safety and reliability of the system.

[0073] It should be understood that the sequence number of each step in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0074] A control and guidance signal drive circuit for an AC charging pile, corresponding to the above embodiment, Figure 5 A schematic diagram of an AC charging pile according to an embodiment of this application is shown. For ease of explanation, only the parts related to the embodiment of this application are shown.

[0075] Reference Figure 5 The AC charging pile 4 in this embodiment includes: a controller 2 and a control guidance signal drive circuit 1 for the AC charging pile as described above, wherein the controller 2 is communicatively connected to the control guidance signal drive circuit 1.

[0076] Controller 2 plays a core control and management role in the operation of AC charging pile 4, controlling its operation. Controller 2 is responsible for generating pulse width modulation (PWM) signals, inputting these signals into the control guidance signal drive circuit 1 to drive the circuit to generate control guidance signals. Based on the voltage amplitude information fed back from the control guidance signal drive circuit 1, controller 2 determines the connection status between AC charging pile 4 and target vehicle 3, as well as the charging status of target vehicle 3, to ensure safe and efficient charging. Control guidance signal drive circuit 1 is responsible for generating and driving control guidance signals to ensure safe and effective communication and charging operations between AC charging pile 4 and electric vehicle.

[0077] The controller 2 and the control guidance signal drive circuit 1 are connected through a specific communication interface. The controller 2 can obtain the voltage amplitude of the sampling signal of the control guidance signal drive circuit 1 in real time, and determine the connection status and charging status between the AC charging pile and the electric vehicle based on the voltage amplitude, thereby achieving precise control of the entire charging process.

[0078] It should be noted that the information interaction and execution process between the modules in the AC charging pile 4 mentioned above are based on the same concept as the method embodiment of this application. For details on their specific functions and technical effects, please refer to the method embodiment section, and they will not be repeated here.

[0079] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, all or part of the processes in the methods of the above embodiments of this application can be implemented by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium, and when executed by a processor, it can implement the steps of the various method embodiments described above. The computer program includes computer program code, which can be in the form of source code, object code, executable files, or certain intermediate forms. A computer-readable medium can include at least: any entity or device capable of carrying computer program code to a photographic device / terminal device, a recording medium, a computer memory, a read-only memory (ROM), a random access memory (RAM), an electrical carrier signal, a telecommunication signal, and a software distribution medium. Examples include USB flash drives, portable hard drives, magnetic disks, or optical disks. In some jurisdictions, according to legislation and patent practice, computer-readable media cannot be electrical carrier signals or telecommunication signals.

[0080] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail or recorded in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0081] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0082] In the embodiments provided in this application, it should be understood that the disclosed apparatus / network devices and methods can be implemented in other ways. For example, the apparatus / network device embodiments described above are merely illustrative. For instance, the division of modules or units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0083] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0084] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A control and guidance signal drive circuit for an AC charging pile, characterized in that, include: The circuit consists of a signal control circuit, a signal interface circuit, and a signal sampling circuit. The signal control circuit is connected to the controller of the AC charging pile and is used to drive the signal interface circuit according to the pulse width modulation signal generated by the controller. The signal interface circuit is connected to the signal control circuit and is used to filter the pulse width modulation signal to obtain a control guidance signal, and send the control guidance signal to the target vehicle; wherein, the control guidance signal represents the connection status between the AC charging pile and the target vehicle and the charging status of the target vehicle during the charging process through voltage amplitude; The signal sampling circuit is connected to the signal control circuit and the signal interface circuit. It is used to collect the voltage amplitude in the control guidance signal and send the voltage amplitude to the controller of the AC charging pile, so that the controller of the AC charging pile can determine the connection status between the AC charging pile and the target vehicle and the charging status of the target vehicle based on the voltage amplitude. The signal control circuit includes: a transistor circuit, an optocoupler, a first resistor, a second resistor, a voltage divider circuit, and a circuit power supply. The input terminal of the transistor circuit is connected to the controller of the AC charging pile; the output terminal of the transistor circuit is connected to the input terminal of the first resistor and the first input terminal of the optocoupler; the second input terminal of the optocoupler is connected to the output terminal of the first resistor; the first resistor is connected to the circuit power supply via the second resistor; the output terminal of the optocoupler is connected to the input terminal of the voltage divider circuit; the output terminal of the voltage divider circuit is connected to the input terminal of the signal interface circuit; and the circuit power supply provides power to the optocoupler. The signal interface circuit includes a third filter circuit, a transient voltage suppression diode, and a thermistor. The input terminal of the third filter circuit is connected to the output terminal of the signal control circuit, and the output terminal of the third filter circuit is connected to the input terminals of the transient voltage suppression diode and the thermistor, respectively, for filtering high-frequency ripple in the pulse width modulation signal. The output terminal of the transient voltage suppression diode is grounded, and the output terminal of the thermistor is connected to the interface resistor of the target vehicle. The third filter circuit includes a first wire-wound inductor, a second wire-wound inductor, a third capacitor, and a fourth capacitor. The input terminal of the first wire-wound inductor is connected to the input terminal of the third capacitor, and the output terminal of the first wire-wound inductor is connected to the input terminals of the fourth capacitor and the second wire-wound inductor, respectively. The output terminals of the third capacitor and the fourth capacitor are grounded. The output terminal of the second wire-wound inductor is connected to the input terminals of the transient voltage suppression diode and the thermistor, respectively.

2. The control and guidance signal drive circuit for an AC charging pile as described in claim 1, characterized in that, The transistor circuit includes: a third resistor, a fourth resistor, and a transistor; wherein, The input terminal of the third resistor is connected to the first signal port of the controller of the AC charging pile, the output terminal of the third resistor is connected to the input terminal of the fourth resistor and the base terminal of the transistor, and the collector terminal of the transistor is connected to the first input terminal of the optocoupler. The output terminal of the fourth resistor and the emitter terminal of the transistor are grounded.

3. The control and guidance signal drive circuit for an AC charging pile as described in claim 2, characterized in that, The voltage divider circuit includes: a first voltage divider resistor, a second voltage divider resistor, a third voltage divider resistor, a fifth resistor, a sixth resistor, a first filter circuit, and a second filter circuit; wherein, The output terminal of the optocoupler is connected to the input terminal of the fifth resistor and the input terminal of the first voltage divider resistor, respectively, and the output terminal of the fifth resistor is grounded. The output terminal of the first voltage divider resistor is connected to the input terminal of the second voltage divider resistor and the input terminal of the first filter circuit, respectively. The output terminal of the first filter circuit is grounded. The first filter circuit includes a first filter resistor and a first capacitor. The output terminal of the second voltage divider resistor is connected to the input terminal of the third voltage divider resistor and the input terminal of the second filter circuit, respectively. The output terminal of the second filter circuit is grounded. The second filter circuit includes a second filter resistor and a second capacitor. The output terminal of the third voltage divider resistor is connected to the input terminal of the sixth resistor, and the output terminal of the sixth resistor is connected to the input terminal of the signal interface circuit and the input terminal of the signal sampling circuit.

4. The control and guidance signal drive circuit for an AC charging pile as described in claim 3, characterized in that, The signal sampling circuit includes: a dual-channel operational amplifier circuit, a clamping diode, and a circuit power supply; wherein... The input terminal of the dual operational amplifier circuit is connected to the output terminal of the signal control circuit; The output terminal of the dual operational amplifier circuit is connected to the input terminal of the clamping diode; The first output terminal of the clamping diode is connected to the second signal port of the controller of the AC charging pile; The input terminal of the clamping diode is connected to the power supply of the circuit, and the second output terminal of the clamping diode is grounded.

5. The control and guidance signal drive circuit for an AC charging pile as described in claim 4, characterized in that, The dual-channel operational amplifier circuit includes: a first-stage operational amplifier circuit, a second-stage operational amplifier circuit, a first sampling resistor, a second sampling resistor, a first sampling capacitor, and a second sampling capacitor; wherein... The first input terminal of the first-stage operational amplifier circuit is connected to the output terminal of the signal control circuit, and the second input terminal of the first-stage operational amplifier circuit is grounded. The output terminal of the first-stage operational amplifier circuit is connected to the input terminal of the first sampling resistor, the output terminal of the first sampling resistor is connected to the first input terminal of the second-stage operational amplifier circuit and the input terminal of the first sampling capacitor, and the output terminal of the first sampling capacitor is grounded. The output terminal of the second-stage operational amplifier circuit is connected to the input terminal of the second sampling resistor, and the output terminal of the second sampling resistor is connected to the input terminal of the second sampling capacitor and the first output terminal of the clamping diode.

6. The control and guidance signal drive circuit for an AC charging pile as described in claim 5, characterized in that, The first-stage operational amplifier circuit includes: a first operational amplifier, a first feedback resistor, a second feedback resistor, a third amplification resistor, a first compensation capacitor, and a first filter capacitor; wherein, The input terminal of the first feedback resistor is connected to the output terminal of the signal control circuit, the output terminal of the first feedback resistor is connected to the negative input terminal of the first operational amplifier, and the second feedback resistor and the first compensation capacitor are connected in parallel to form a first parallel circuit. The input terminal of the first parallel circuit is connected to the negative input terminal of the first operational amplifier, and the output terminal of the first parallel circuit is connected to the output terminal of the first operational amplifier. The third amplifying resistor and the first filtering capacitor form a second parallel circuit. The output terminal of the second parallel circuit is grounded, and the input terminal of the second parallel circuit is connected to the positive input terminal of the first operational amplifier. The output terminal of the first operational amplifier is connected to the input terminal of the first sampling resistor.

7. The control and guidance signal drive circuit for an AC charging pile as described in claim 6, characterized in that, The second-stage operational amplifier circuit includes: a second operational amplifier, a fourth feedback resistor, a fifth feedback resistor, a sixth amplification resistor, a seventh amplification resistor, a second compensation capacitor, and a second filter capacitor; wherein, The input terminal of the fourth feedback resistor is connected to the output terminal of the first sampling resistor, the output terminal of the fourth feedback resistor is connected to the negative input terminal of the second operational amplifier, and the fifth feedback resistor and the second compensation capacitor are connected in parallel to form a third parallel circuit. The input terminal of the third parallel circuit is connected to the negative input terminal of the second operational amplifier, and the output terminal of the third parallel circuit is connected to the output terminal of the second operational amplifier. The sixth amplifying resistor and the second filtering capacitor form a fourth parallel circuit. The output terminal of the fourth parallel circuit is grounded, and the input terminal of the fourth parallel circuit is connected to the positive input terminal of the second operational amplifier. The power supply of the circuit is connected to the positive input terminal of the second operational amplifier through the seventh amplifying resistor. The output terminal of the second operational amplifier is connected to the input terminal of the second sampling resistor.

8. An AC charging pile, characterized in that, include: The controller and the control guidance signal drive circuit of the AC charging pile as described in any one of claims 1 to 7 are communicatively connected.

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