Grounding detection circuit and charging pile

Abstract

The utility model provides a grounding detection circuit and a charging pile. The grounding detection circuit comprises a first module which is connected with a grounding sampling end; the second module is connected to the first module and used for forming a direct-current voltage signal at the grounding sampling end, and the grounding sampling end is in a first voltage state under the superposition effect of the direct-current voltage signal and the alternating-current voltage signal of the first module when the charging pile is in a grounding state; and the grounding sampling end presents a second voltage state under the action of the direct-current voltage signal when the charging pile is in a non-grounding state. In the scheme, the DC voltage signal is formed at the grounding sampling end through the second module, the voltage signal is prevented from floating, and the detection precision is improved.

Description

Technical Field

[0001] The present application relates to the technical field of charging piles, and in particular to a ground detection circuit and a charging pile. Background Art

[0002] Currently, all AC charging piles need to be grounded. Only well-grounded charging piles can effectively avoid the risk of electric shock when users come into contact with the metal shell of the charging pile or the metal shell of the vehicle during charging.

[0003] In the prior art, the grounding detection system usually converts the AC voltage signal into a DC voltage signal after sorting and filtering, and determines whether it is grounded by detecting the DC voltage signal, thereby achieving detection. However, the existing grounding detection system will be affected by signal floating, resulting in inaccurate grounding detection results. Utility Model Content

[0004] In view of this, the purpose of the present application is to provide a ground detection circuit and a charging pile, which form a DC voltage signal at the ground sampling end through a second module to avoid the voltage signal floating and improve the detection accuracy.

[0005] In a first aspect, the present application provides a ground detection circuit, comprising:

[0006] The first module is connected to the first module and connected to the ground sampling terminal;

[0007] The second module is connected to the first module and is used to form a DC voltage signal at the grounded sampling end. When the charging pile is in a grounded state, the grounded sampling end is acted upon by the DC voltage signal and the AC voltage signal of the first module to present a first voltage state. When the charging pile is in a non-grounded state, the grounded sampling end is acted upon by the DC voltage signal to present a second voltage state.

[0008] The grounding detection circuit provided in the present application includes a first module and a second module. When the charging pile is in a grounded state, the grounding sampling end is superimposed with the AC voltage signal of the first module and the DC voltage signal of the second module to present a first voltage state. The second module is used to form a DC voltage signal at the grounding sampling end, so that the grounding sampling end is acted upon by the DC voltage signal to present a second voltage state when the charging pile is not in a grounded state, thereby avoiding the voltage signal of the grounding sampling end from floating and improving the detection accuracy.

[0009] In combination with the first aspect, in a possible implementation, the first module includes a plurality of circuit devices connected in series, the plurality of circuit devices are connected between the ground sampling terminal and the AC-L port; the plurality of circuit devices include at least one isolation device to isolate the DC voltage component of the ground sampling terminal from the AC-L port. It can be understood that the first module isolates the DC voltage signal of the AC-L port from the ground sampling terminal through at least one isolation device, thereby avoiding the influence of the DC voltage signal of the AC-L port on the detection circuit and improving the accuracy of the detection result.

[0010] In combination with the first aspect, in a possible implementation, the multiple circuit devices include a first capacitor and a second capacitor, the first capacitor is used to divide the AC voltage signal of the AC-L port, and the second capacitor is used to isolate the DC voltage component of the AC-L port from the ground terminal. It can be understood that the first capacitor in the multiple circuit devices is used to isolate the DC voltage signal from the AC-L port, and is also used to step down and divide the AC voltage signal of the AC-L port to protect the circuit, and the DC voltage signal between the AC-L port and the ground terminal of the charging pile is isolated by the second capacitor in the multiple circuit devices. Avoid the ground sampling terminal of the detection circuit from being affected by the DC voltage signal, and improve the accuracy of the detection result.

[0011] In combination with the first aspect, in a possible implementation, the plurality of circuit components further include a first resistor and a second resistor; the first capacitor, the first resistor, the second resistor and the second capacitor are connected in series in sequence, an end of the first capacitor away from the first resistor is used to connect to the AC-L port, and an end of the second capacitor away from the second resistor is used to connect to the ground terminal. It can be understood that the first capacitor, the first resistor, the second resistor and the second capacitor cooperate to step down and divide the AC voltage signal of the AC-L port, and the DC voltage signal of the AC-L port is isolated by the first capacitor, thereby improving the accuracy of the detection result.

[0012] In combination with the first aspect, in a possible implementation, the second module includes a DC power supply and a third resistor; the DC power supply is connected to the first end of the third resistor, and the second end of the third resistor is connected to the circuit between the first resistor and the second resistor. It can be understood that, through the cooperation of the DC power supply and the third resistor of the second module and the step-down voltage divider circuit of the first module, a DC voltage signal of the second voltage value is formed at the grounded sampling end, so as to avoid the voltage signal from floating and improve the detection accuracy.

[0013] In combination with the first aspect, in a possible implementation, the voltage value of the AC voltage signal formed by the first module at the ground sampling end is a first voltage value; the voltage value of the DC voltage signal formed by the second module at the ground sampling end is a second voltage value; when the grounding state of the charging pile is grounded, the second voltage value is greater than or equal to the first voltage value. It can be understood that the second voltage value is greater than or equal to the first voltage value, so that the voltage signal collected at the ground sampling end is a fully positive sinusoidal voltage signal, thereby increasing the detected voltage signal range.

[0014] In combination with the first aspect, in a possible implementation, the ground detection circuit further includes a third module, the third module is connected to the ground sampling terminal, and is used to collect the voltage signal of the ground sampling terminal, and determine the grounding state of the charging pile according to the collected first voltage state and the second voltage state. It can be understood that the ground detection circuit further includes a third module, and the voltage signal of the ground sampling terminal is collected by the third module, and the grounding state of the charging pile is determined according to the collected voltage signal, so as to improve the determination efficiency.

[0015] In combination with the first aspect, in a possible implementation, the third module includes a sampling chip, and the sampling chip is connected to the grounded sampling terminal and the digital ground. It can be understood that the voltage signal of the grounded sampling terminal is collected by the sampling chip and processed to improve the efficiency and accuracy of the detection result.

[0016] In combination with the first aspect, in a possible implementation, the ground detection circuit further includes a fourth module; the fourth module is connected to the ground sampling terminal, the ground terminal and the digital ground, and is used to suppress the instantaneous high voltage caused by the surge, so as to prevent the instantaneous high voltage from damaging the pins of the sampling chip. It is understandable that the ground detection circuit further includes a fourth module, and the fourth module is used to prevent the instantaneous high voltage caused by the surge from damaging the components in the third module, thereby extending the service life of the equipment.

[0017] In combination with the first aspect, in a possible implementation, the fourth module includes a transient voltage suppression diode, a first connection end of the transient voltage suppression diode is connected to the ground sampling end, and a second connection end of the transient voltage suppression diode is connected to the ground end and the digital ground. It can be understood that the transient voltage suppression diode prevents the instantaneous high voltage caused by the surge from damaging the components in the third module, thereby extending the service life of the equipment.

[0018] In a second aspect, an embodiment of the present application provides a charging pile, comprising a grounding detection circuit as provided in the first aspect and any one of its possible implementations. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0020] Figure 1 It is a structural schematic diagram of a ground detection circuit provided in an embodiment of the present application;

[0021] Figure 2 It is a structural schematic diagram of another ground detection circuit provided in an embodiment of the present application;

[0022] Figure 3 is a structural schematic diagram of a ground detection circuit including a third module provided in an embodiment of the present application;

[0023] Figure 4 is a structural schematic diagram of a ground detection circuit including a fourth module provided in an embodiment of the present application;

[0024] Figure 5 It is a waveform diagram of a voltage signal detected by the detection unit provided in the embodiment of the present application;

[0025] Figure 6 is another waveform diagram of a voltage signal detected by the detection unit provided in an embodiment of the present application;

[0026] Figure 7 It is a structural schematic diagram of a charging pile provided in an embodiment of the present application.

[0027] The following are the descriptions of the reference numerals:

[0028] 1- ground detection circuit; 2- charging pile; 10- first module; 20- second module; 30- third module;

[0029] 301-microcontroller unit; 40-fourth module; 401-first connection terminal; 402-second connection terminal; 50-AC-L port; 60-ground sampling terminal; 70-ground terminal; C1-first capacitor; C2-second capacitor; R1-first resistor; R2-second resistor; R3-third resistor; TVS-transient voltage suppression diode; DGND-digital ground; VCC-power supply; Voffset-DC power supply; PE-grounding point. DETAILED DESCRIPTION

[0030] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0031] The terms "first", "second", etc. in the specification and claims of this application and the above drawings are used to distinguish different objects rather than to describe a specific order. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusions.

[0032] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0033] The embodiments of the present application are described below with reference to the accompanying drawings.

[0034] See also Figure 1 and Figure 2 , Figure 1 is a structural diagram of a ground detection circuit provided in an embodiment of the present application, Figure 2 FIG. 1 is a schematic diagram of another ground detection circuit provided in an embodiment of the present application. Figure 1 and Figure 2 As shown, a ground detection circuit 1 includes:

[0035] The first module 10 is connected to the grounded sampling terminal 60;

[0036] The second module 20 is connected to the first module 10 and is used to form a DC voltage signal at the grounding sampling terminal 60. When the charging pile 2 is in a grounded state, the grounding sampling terminal 60 is superimposed with the DC voltage signal and the AC voltage signal of the first module 10 to present a first voltage state. When the charging pile 2 is in a non-grounded state, the grounding sampling terminal 60 is acted upon by the DC voltage signal to present a second voltage state.

[0037] Please combine Figure 7 The ground detection circuit 1 is arranged in the charging pile 2, and the charging pile 2 is an AC charging pile 2.

[0038] Among them, the second module 20 is connected to the first module 10 to form an AC voltage signal at the grounding sampling terminal 60 connected to the first module 10. When the charging pile 2 is grounded, an effective AC voltage signal will be formed at the grounding sampling terminal 60, so the grounding sampling terminal 60 is superimposed by the AC voltage signal and the DC voltage signal to present a first voltage state; when not grounded, no effective AC voltage signal can be formed at the grounding sampling terminal 60, and the grounding sampling terminal 60 is acted on by the DC voltage signal of the second module 20 to present a second voltage state. Therefore, according to the comparison result of the voltage signal collected at the grounding sampling terminal 60 and the voltage state, it can be judged whether the charging pile 2 is grounded.

[0039] For example, the distribution characteristic of the voltage signal collected at the ground sampling terminal 60 can be the first difference between the maximum amplitude and the minimum amplitude of the voltage signal, and then the second difference between the maximum amplitude and the minimum amplitude of the first voltage state and the third difference between the maximum amplitude and the minimum amplitude of the second voltage state can be obtained. If the first difference is close to the second difference, that is, the phase difference between the first difference and the second difference is less than the phase difference between the first difference and the third difference, it is close to the first voltage state, so it is determined that the grounding state of the charging pile 2 is grounded. If the first difference is close to the third difference, that is, the phase difference between the first difference and the second difference is greater than the phase difference between the first difference and the third difference, it is close to the second voltage state, so it is determined that the grounding state of the charging pile 2 is not grounded.

[0040] It can be seen that in this example, the second module 20 forms a DC voltage signal at the grounding sampling terminal 60, so that when the charging pile 2 is grounded, the grounding sampling terminal 60 is superimposed by the AC voltage signal and the DC voltage signal to present a first voltage state; when not grounded, the grounding sampling terminal 60 is acted on by the DC voltage signal in the non-grounding state of the charging pile 2 to present a second voltage state, so that the grounding state of the charging pile 2 can be determined according to the voltage signal and voltage state collected by the grounding sampling terminal 60, thereby improving the accuracy of the detection result. And by providing a DC voltage signal through the second module 20, the voltage signal is prevented from floating, thereby improving the detection accuracy.

[0041] In one possible example, see again Figure 2 The first module 10 includes a plurality of circuit devices connected in series, and the plurality of circuit devices are connected between the ground sampling terminal 60 and the AC-L port 50; the plurality of circuit devices include at least one isolation device to isolate the DC voltage component between the ground sampling terminal 60 and the AC-L port 50.

[0042] The AC-L port 50 of the charging pile 2 is an output port for outputting an AC voltage signal in the charging pile 2. The AC voltage signal output by the AC-L port 50 comes from an energy storage station or a mains supply. Specifically, the AC-L port 50 can output a 220V AC voltage signal or a 380V AC voltage signal, which is not limited here.

[0043] The device types of the multiple circuit devices may be resistors and capacitors. The resistance characteristics of the capacitors in the AC power grid can play a role in dividing and reducing the voltage signal. The resistors as voltage-reducing elements can also play a role in dividing and reducing the voltage.

[0044] It can be seen that in this example, multiple circuit devices connected in series can effectively step down and divide the voltage signal of the AC-L port 50, so that the sampled voltage signal of the ground sampling terminal 60 is covered within the effective detection range as much as possible. At the same time, at least one isolation device isolates the DC voltage signal between the AC-L port 50 and the ground sampling terminal 60, which can avoid the problem of misidentification of the ground detection result caused by the DC voltage signal and improve the detection accuracy.

[0045] In a possible example, the multiple circuit devices include a first capacitor C1 and a second capacitor C2, the first capacitor C1 is used to divide the AC voltage signal of the AC-L port 50, and the second capacitor C2 is used to isolate the DC voltage component of the AC-L port 50 and the ground terminal 70.

[0046] The plurality of circuit components include a first capacitor C1 and a second capacitor C2. The first capacitor C1 is a component in at least one isolation component. While the first capacitor C1 divides the AC voltage signal of the AC-L port 50, the first capacitor C1 can also isolate possible DC voltage signals of the AC-L port 50. The ground terminal 70 is a ground terminal of the charging pile 2 that can be connected to the ground point PE.

[0047] It can be seen that the first capacitor C1 divides the AC voltage signal of the AC-L port 50, and can isolate the influence of the DC voltage signal on the ground sampling terminal 60 through the first capacitor C1, and isolate the influence of the DC voltage signal on the ground terminal 70 through the second capacitor C2, thereby improving the detection accuracy.

[0048] In one possible example, see again Figure 2 , the multiple circuit devices also include a first resistor R1 and a second resistor R2; the first capacitor C1, the first resistor R1, the second resistor R2 and the second capacitor C2 are connected in series in sequence, the end of the first capacitor C1 away from the first resistor R1 is used to connect to the AC-L port 50, and the end of the second capacitor C2 away from the second resistor R2 is used to connect to the ground terminal 70.

[0049] Among them, the first capacitor C1, the first resistor R1, the second resistor R2 and the second capacitor C2 are connected in series, and the ground sampling terminal 60 is connected between the second resistor R2 and the second capacitor C2. The first capacitor C1 cooperates with the first resistor R1, the second resistor R2 and the second capacitor C2 to step down and divide the AC voltage of the AC-L port 50. In the circuit connection relationship of the multiple circuit components, the voltage signal of the ground sampling terminal 60 can be characterized as the potential of the end of the second capacitor C2 away from the ground end of the charging pile 2.

[0050] It can be seen that in this example, the first capacitor C1, the first resistor R1, the second resistor R2 and the second capacitor C2 connected in series can effectively reduce the voltage signal of the AC-L port 50 to improve the effectiveness of signal detection, and the first capacitor C1 can effectively isolate the DC voltage component of the AC-L port 50 to improve the detection accuracy.

[0051] In one possible example, see Figure 2 .like Figure 2 As shown, the second module 20 includes a DC power supply Voffset and a third resistor R3; the DC power supply Voffset is connected to a first end of the third resistor R3, and a second end of the third resistor R3 is connected to a circuit between the first resistor R1 and the second resistor R2.

[0052] Among them, the first module 10 includes a first capacitor C1, a first resistor R1, a second resistor R2 and a second capacitor C2 connected in series in sequence; the AC-L port 50 is connected to the first capacitor C1, and the second capacitor C2 is connected to the ground terminal 70 of the charging pile 2; the second end of the third resistor R3 is connected to the circuit between the first resistor R1 and the second resistor R2. Since the equivalent resistance of the second capacitor C2 in the DC circuit is much greater than the resistance of the third resistor R3 and the second resistor R2, the DC voltage signal of the DC power supply Voffset is directly divided across the second capacitor C2, so a DC voltage signal is formed at the ground sampling terminal 60.

[0053] It can be seen that in this example, the second module 20 forms a DC voltage signal at the ground sampling terminal 60, which can prevent the voltage signal of the ground sampling terminal 60 from floating and improve the detection accuracy.

[0054] In a possible example, the voltage value of the AC voltage signal formed by the first module 10 at the ground sampling terminal 60 is a first voltage value; the voltage value of the DC voltage signal formed by the second module 20 at the ground sampling terminal 60 is a second voltage value; when the grounding state of the charging pile 2 is grounded, the second voltage value is greater than or equal to the first voltage value.

[0055] Among them, the grounding state of the charging pile 2 includes grounding and ungrounding. By judging whether the grounding sampling terminal 60 is in the first voltage state or the second voltage state, it can be determined whether the charging pile 2 is grounded or ungrounded. Specifically, the voltage state of the grounding sampling terminal 60 can be determined by collecting the voltage signal of the grounding sampling terminal 60. That is, if the grounding state of the charging pile 2 is a grounded state, the voltage signal formed by the grounding sampling terminal 60 includes an AC voltage signal and a DC voltage signal, wherein the voltage value of the AC voltage signal is a first voltage value, the voltage value of the DC voltage signal is a second voltage value, and the second voltage value is greater than or equal to the first voltage value. The negative half of the AC voltage signal can be raised to the positive voltage signal range, so that a full positive sinusoidal wave voltage signal can be collected at the grounding sampling terminal 60, thereby increasing the detection range of the voltage signal and improving the accuracy of the detection result.

[0056] If the grounding state of the charging pile 2 is a non-grounded state, an effective AC voltage signal cannot be formed at the grounding sampling terminal 60. However, since the second module 20 provides a DC voltage signal, the voltage signal collected at the grounding sampling terminal 60 is a DC voltage signal, which avoids the voltage signal from floating and improves the detection accuracy.

[0057] It can be seen that in this example, the first module 10 can form an AC voltage signal of a first voltage value at the ground sampling terminal 60, and the second module 20 can form a DC voltage signal of a second voltage value at the ground sampling terminal 60, and the second voltage value is greater than the first voltage value, so as to improve the detection range of the effective voltage signal in the positive interval, thereby improving the accuracy of the detection result.

[0058] In one possible example, see Figure 3 , Figure 3 FIG. 1 is a schematic diagram of a ground detection circuit including a third module provided in an embodiment of the present application. Figure 3 As shown, the ground detection circuit 1 also includes a third module 30, which is connected to the ground sampling terminal 60, for collecting the voltage signal of the ground sampling terminal 60, and determining the grounding state of the charging pile 2 according to the collected first voltage state and the second voltage state.

[0059] Among them, after the third module 30 collects the voltage signal, the maximum amplitude and the minimum amplitude of the collected voltage signal are obtained, and the difference between the maximum amplitude and the minimum amplitude is calculated, and whether to be grounded is determined based on the comparison result of the difference with the first voltage state and the second voltage state.

[0060] Alternatively, since the voltage signal includes multiple sampled values ​​that are distributed over time and not absolutely uniformly distributed, the first amplitude of the peak and the second amplitude of the trough of the collected voltage signal are determined, the third amplitude of the peak and the fourth amplitude of the trough of the first voltage state are determined, and the single value corresponding to the second voltage state is determined. The first similarity between the first amplitude and the third amplitude is calculated, the second similarity between the second amplitude and the fourth amplitude is calculated, and the first average value of the first similarity and the second similarity is calculated; the third similarity between the first amplitude and the single value is calculated, the fourth similarity between the second amplitude and the single value is calculated, and the second average value of the third similarity and the fourth similarity is calculated. If the first average value is greater than the second average value, the grounding state is determined to be grounded, and if the second average value is greater than the first average value, the grounding state is determined to be non-grounded. It can be understood that multiple amplitudes of the voltage signal can be determined according to actual needs, and the similarity is compared with the multiple amplitudes of the first state value, and the similarity is compared with the single value of the second state value, so as to improve the accuracy of the comparison result.

[0061] For example, please combine Figure 5 , Figure 5 It is a waveform diagram of the voltage signal detected by the detection unit provided in the embodiment of the present application. If the charging pile 2 is grounded, and the AC-L port 50 outputs a 220V AC voltage signal, the first capacitor C1 is preset to be 22 nanofarads, the first resistor R1 is 4.4 megohms, the second resistor R2 is 1 kiloohm, the second capacitor C2 is 10 nanofarads, and the third resistor R3 is 10 kiloohms. At this time, the AC voltage signal is stepped down and divided by the first capacitor C1, the first resistor R1, the second resistor R2 and the second capacitor C2. The 220V AC voltage signal is stepped down to a ±1.65V sinusoidal AC voltage signal by the first capacitor C1 and the first resistor R1, and then divided by the second resistor R2 and the second capacitor C2; at the same time, a 1.65V DC voltage signal is provided by the DC power supply Voffset, the third resistor R3 and the second resistor R2, so as to completely raise the AC signal to a positive sinusoidal voltage signal. The third module 30 collects voltage signals, such as Figure 5 As shown, the voltage signal collected by the third module 30 is a full positive sinusoidal voltage signal. Figure 5 The horizontal axis of the coordinate is the period T, and the vertical axis is the voltage amplitude V. Since the second module 20 provides a 1.65V DC voltage signal, a waveform diagram of a voltage signal fluctuating at 1.65V is obtained. The difference ΔV between the maximum amplitude and the minimum amplitude in the voltage signal is obtained. If ΔV is close to the preset value corresponding to the first voltage state, it is determined that the charging pile 2 is grounded. The preset value can be an empirical value, which is not limited here.

[0062] If the charging pile 2 is not grounded, no effective AC voltage signal can be formed at the grounded sampling terminal 60, and only a DC voltage signal is collected at the grounded sampling terminal 60. Therefore, the difference between the maximum amplitude and the minimum amplitude corresponding to the second voltage state is preset to be 0V. Figure 6 , Figure 6 is another waveform diagram of the voltage signal detected by the detection unit provided in the embodiment of the present application, such as Figure 6 As shown, if the charging pile 2 is not grounded, and the DC power supply, the third resistor R3 and the second resistor R2 cooperate to provide a DC voltage signal of 1.65V, the waveform of the voltage signal collected by the third module 30 is as follows Figure 6 As shown, Figure 6 The horizontal axis of the coordinate is the period T, and the vertical axis is the voltage amplitude V. A waveform of a DC voltage close to 1.65V is obtained. Therefore, the voltage signal amplitude ΔV is close to 0V, which means that it is determined that the ground is not connected.

[0063] In addition, the third module 30 is also connected to the digital ground DGND and the power supply VCC, and the power supply VCC independently supplies power to the third module 30 to improve detection stability.

[0064] It is understandable that if the charging pile 2 inputs other levels of voltage, such as 380V, the parameters of the electronic components in the ground detection circuit 1 can be changed and adjusted according to actual needs, and the specific parameters of the electronic components in the ground detection circuit 1 are not limited here.

[0065] It can be seen that, in this example, the detection result is determined by the third module 30, which improves the credibility of the determination result.

[0066] In a possible example, the third module 30 includes a sampling chip, and the sampling chip is connected to the ground sampling terminal 60 and a digital ground DGND.

[0067] The third module 30 includes a sampling chip, which is connected to the ground sampling terminal 60, the digital ground DGND and the power supply VCC. The sampling chip collects the voltage signal of the ground sampling terminal 60 to determine whether the charging pile 2 is grounded according to the collected voltage signal. It can be understood that the sampling chip can be a microcontroller unit 301 (MCU).

[0068] It can be seen that in this example, the collected voltage signal is processed by the sampling chip to output the detection result, thereby improving the acquisition efficiency, and the sampling chip is powered by an independent power supply to improve the stability of the processing process.

[0069] In one possible example, see Figure 4 , Figure 4 FIG. 1 is a schematic diagram of a ground detection circuit including a fourth module provided in an embodiment of the present application. Figure 4As shown, the ground detection circuit 1 also includes a fourth module 40; the fourth module 40 is connected to the ground sampling terminal 60, the ground terminal 70 and the digital ground DGND, and is used to suppress the instantaneous high voltage caused by surge to avoid the instantaneous high voltage from damaging the pins of the sampling chip.

[0070] The fourth module 40 includes a transient voltage suppression diode TVS, a first connection terminal 401 of the transient voltage suppression diode TVS is connected to the ground sampling terminal 60, and a second connection terminal 402 of the transient voltage suppression diode TVS is connected to the ground terminal 70 and the digital ground DGND.

[0071] It is understandable that the fourth module 40 may also include other devices for preventing instantaneous high voltage, so as to prevent the sampling chip in the third module 30 from being damaged by instantaneous high voltage caused by lightning strike or other surges.

[0072] It can be seen that, in this example, the sampling chip in the third module 30 is protected by the fourth module 40, thereby extending the service life of the circuit.

[0073] See also Figure 7 , Figure 7 Schematic diagram of the structure of a charging pile provided in an embodiment of the present application. Based on the same concept, the present application also provides a charging pile 2, the charging pile 2 comprising the grounding detection circuit 1 in any of the above embodiments.

[0074] The embodiments of the present application are introduced in detail above. Specific examples are used in this article to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method of the present application and its core idea. At the same time, for those skilled in the art, according to the idea of ​​the present application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

[0075] Although the present application is disclosed as above, the present application is not limited thereto. Any person skilled in the art can easily think of changes or substitutions without departing from the spirit and scope of the present application, and can make various changes and modifications, including the combination of the above-mentioned different functions and implementation steps, including software and hardware implementation methods, all of which are within the scope of protection of the present application.

Claims

1. A ground detection circuit, characterized in that: include: The first module is connected to the ground sampling terminal; The second module is connected to the first module and is used to form a DC voltage signal at the grounded sampling end. When the charging pile is in a grounded state, the grounded sampling end is acted upon by the DC voltage signal and the AC voltage signal of the first module to present a first voltage state. When the charging pile is in a non-grounded state, the grounded sampling end is acted upon by the DC voltage signal to present a second voltage state.

2. The ground detection circuit according to claim 1, characterized in that: The first module includes a plurality of circuit devices connected in series, and the plurality of circuit devices are connected between the ground sampling terminal and the AC-L port; The plurality of circuit devices include at least one isolation device to isolate the ground sampling terminal from a DC voltage component of the AC-L port.

3. The ground detection circuit according to claim 2, characterized in that: The plurality of circuit components include a first capacitor and a second capacitor, wherein the first capacitor is used to divide the AC voltage signal of the AC-L port, and the second capacitor is used to isolate a DC voltage component between the AC-L port and a ground terminal.

4. The ground detection circuit according to claim 3, characterized in that: The plurality of circuit devices further include a first resistor and a second resistor; The first capacitor, the first resistor, the second resistor and the second capacitor are connected in series in sequence, an end of the first capacitor away from the first resistor is used to connect to the AC-L port, and an end of the second capacitor away from the second resistor is used to connect to the ground terminal.

5. The ground detection circuit according to claim 4, characterized in that: The second module includes a DC power supply and a third resistor; The DC power supply is connected to a first end of the third resistor, and a second end of the third resistor is connected to a circuit between the first resistor and the second resistor.

6. The ground detection circuit according to any one of claims 1 to 4, characterized in that: The voltage value of the AC voltage signal formed by the first module at the ground sampling end is a first voltage value; The voltage value of the DC voltage signal formed by the second module at the ground sampling end is a second voltage value; When the charging pile is in a grounded state, the second voltage value is greater than or equal to the first voltage value.

7. The ground detection circuit according to claim 3 or 4, characterized in that: The ground detection circuit also includes a third module, which is connected to the ground sampling terminal and is used to collect a voltage signal from the ground sampling terminal and determine a grounding state of the charging pile according to the collected first voltage state and the second voltage state.

8. The ground detection circuit according to claim 7, characterized in that: The third module includes a sampling chip, and the sampling chip is connected to the ground sampling terminal and the digital ground.

9. The ground detection circuit according to claim 8, characterized in that: The ground detection circuit also includes a fourth module; The fourth module is connected to the ground sampling terminal, the ground terminal and the digital ground, and is used to suppress the instantaneous high voltage caused by surge to prevent the instantaneous high voltage from damaging the pins of the sampling chip.

10. The ground detection circuit according to claim 9, characterized in that: The fourth module includes a transient voltage suppression diode, a first connection end of the transient voltage suppression diode is connected to the ground sampling end, and a second connection end of the transient voltage suppression diode is connected to the ground end and the digital ground.

11. A charging pile, characterized in that: The invention comprises a ground detection circuit as claimed in any one of claims 1 to 10.

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