Charging circuit and charging pile

Abstract

The utility model provides a charging circuit and a charging pile. The charging circuit comprises a signal circuit used for outputting a square wave signal with an adjustable duty ratio, the square wave signal is output to a to-be-charged load through a charging gun on the charging pile, and the time of a rising edge of the square wave signal is within 2 microseconds; the first end of the energy storage circuit is connected with the output end of the signal circuit, and the second end of the energy storage circuit is grounded; the first end of the filter circuit is used for being connected with a power supply, the power supply is connected with the load to be charged through a charging gun on the charging pile, and the second end of the filter circuit is grounded; and when the to-be-charged load receives the square wave signal, the maximum charging current value is determined based on the square wave signal, and electric energy provided by the power supply is obtained through a charging gun on the charging pile according to the maximum charging current value. The rising edge time of the square wave signal can be delayed, and the problem of conduction disturbance is avoided.

Description

Technical Field

[0001] This application relates to the field of electric vehicle charging technology, and in particular to a charging circuit and a charging pile. Background Technology

[0002] According to GB / T18487 AC Charging Control Guidance Circuit and Control Principle issued by the National Standardization Management Committee, the charging status guidance between AC charging piles and electric vehicles relies on the CP (Control Confirmation) line signal status. The CP line is one of the signal lines in the charging gun.

[0003] During charging, the CP line sends a PWM wave with a certain duty cycle to the vehicle from the charging pile, based on the charging pile's design power. The vehicle then adjusts the maximum charging current according to this duty cycle. Since the CP line and the power line are both inside the charging gun, the CP signal continuously sends PWM waves during charging. The frequency of these PWM waves couples to the power line of the charging gun, causing conducted interference during charging. Summary of the Invention

[0004] Therefore, it is necessary to provide a charging circuit and a charging pile to address the aforementioned technical problems.

[0005] A charging circuit, applied to a charging pile, the charging circuit comprising:

[0006] The signal circuit is used to output a square wave signal with an adjustable duty cycle. The square wave signal is output to the load to be charged through the charging gun on the charging pile. The rise time of the square wave signal is within 2 microseconds.

[0007] An energy storage circuit, wherein a first terminal of the energy storage circuit is connected to the output terminal of the signal circuit, and a second terminal of the energy storage circuit is grounded; and

[0008] A filter circuit, wherein the first terminal of the filter circuit is used to connect to a power source, the power source is connected to the load to be charged through a charging gun on the charging pile, and the second terminal of the filter circuit is grounded;

[0009] When the load to be charged receives the square wave signal, it determines the maximum charging current value based on the square wave signal, and obtains the power supplied by the power source through the charging gun on the charging pile according to the maximum charging current value.

[0010] In one embodiment, the energy storage circuit includes:

[0011] The first capacitor has its first terminal connected to the output terminal of the signal circuit, and its second terminal grounded. The capacitance of the first capacitor ranges from 300pF to 1600pF.

[0012] In one embodiment, the capacitance of the first capacitor is 1000pF.

[0013] In one embodiment, the power supply is a single-phase power supply, and the filter circuit includes:

[0014] The second capacitor has its first terminal connected to the neutral wire of the single-phase power supply and its second terminal grounded.

[0015] The third capacitor has its first terminal connected to the live wire of the single-phase power supply, and its second terminal grounded.

[0016] In one embodiment, the power supply is a three-phase power supply, and the filter circuit includes:

[0017] The second capacitor has its first terminal connected to the neutral wire of the three-phase power supply and its second terminal grounded.

[0018] The third capacitor has its first terminal connected to the first phase line of the three-phase power supply, and its second terminal grounded.

[0019] The fourth capacitor has its first terminal connected to the second phase line of the three-phase power supply, and its second terminal grounded.

[0020] The fifth capacitor has its first terminal connected to the third phase line of the three-phase power supply, and its second terminal grounded.

[0021] In one embodiment, the capacitance of the second capacitor and the third capacitor is 22nF.

[0022] In one embodiment, the signal circuit includes:

[0023] A pulse signal source is connected to the first terminal of the energy storage circuit. The pulse signal source is used to output a PWM signal with an adjustable duty cycle. The transmission frequency of the pulse signal source is 1KHz.

[0024] A charging station includes:

[0025] The charging pile itself;

[0026] A charging gun, connected to the charging pile body, is used to charge the load to be charged; and

[0027] A charging circuit is disposed within the charging pile body;

[0028] The charging circuit includes:

[0029] The signal circuit is used to output a square wave signal with an adjustable duty cycle. The square wave signal is output to the load to be charged through the charging gun. The rise time of the square wave signal is within 2 microseconds.

[0030] An energy storage circuit, wherein a first terminal of the energy storage circuit is connected to the output terminal of the signal circuit, and a second terminal of the energy storage circuit is grounded;

[0031] A filter circuit, wherein the first terminal of the filter circuit is used to connect to a power source, the power source is connected to the load to be charged through the charging gun, and the second terminal of the filter circuit is grounded;

[0032] When the load to be charged receives the square wave signal, it determines the maximum charging current value based on the square wave signal, and obtains the electrical energy provided by the power source through the charging gun according to the maximum charging current value.

[0033] In one embodiment, the energy storage circuit includes:

[0034] The first capacitor has its first terminal connected to the output terminal of the signal circuit, and its second terminal grounded. The capacitance of the first capacitor ranges from 300pF to 1600pF.

[0035] In one embodiment, the power supply is a single-phase power supply, and the filter circuit includes:

[0036] The second capacitor has its first terminal connected to the neutral wire of the single-phase power supply and its second terminal grounded.

[0037] The third capacitor has its first terminal connected to the live wire of the single-phase power supply, and its second terminal grounded.

[0038] Compared with existing technologies, the aforementioned charging circuit and charging pile include: a signal circuit for outputting a square wave signal with an adjustable duty cycle, the square wave signal being output to the load to be charged via a charging gun on the charging pile, the rise time of the square wave signal being within 2 microseconds; an energy storage circuit, the first terminal of which is connected to the output terminal of the signal circuit, and the second terminal of which is grounded; and a filter circuit, the first terminal of which is connected to a power supply, the power supply being connected to the load to be charged via a charging gun on the charging pile, and the second terminal of which is grounded; when the load to be charged receives the square wave signal, it determines a maximum charging current value based on the square wave signal, and obtains electrical energy provided by the power supply through the charging gun on the charging pile according to the maximum charging current value. This application, through the combination of the energy storage circuit and the filter circuit in the above circuit, can delay the rise time of the square wave signal, which not only avoids the problem of conducted interference but also improves the anti-interference capability of the signal during transmission. Attached Figure Description

[0039] To more clearly illustrate the technical solutions in the embodiments of this application or the conventional technology, the drawings used in the description of the embodiments or the conventional technology 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.

[0040] Figure 1 A circuit schematic diagram of a charging circuit provided in an embodiment of this application;

[0041] Figure 2 A circuit schematic diagram of a charging circuit provided in another embodiment of this application;

[0042] Figure 3 The circuit diagram of a charging pile provided in one embodiment of this application is shown.

[0043] Explanation of reference numerals in the attached figures:

[0044] 10. Charging circuit; 100. Signal circuit; 101. Load to be charged; 110. Pulse signal source; 20. Charging pile; 21. Charging gun; 22. Charging pile body; 200. Energy storage circuit; 210. First capacitor; 300. Filtering circuit; 301. Power supply; 310. Second capacitor; 320. Third capacitor; 330. Fourth capacitor; 340. Fifth capacitor. Detailed Implementation

[0045] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0046] The serial numbers assigned to components in this document, such as "first" and "second," are used solely to distinguish the objects being described and do not have any sequential or technical meaning. The terms "connection" and "linkage" used in this application, unless otherwise specified, include both direct and indirect connections (linkages). It should be understood that the terms "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used solely for the convenience of describing this application and for simplification, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0047] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0048] It should be noted that when a component is said to be "fixed to" another component, it can be directly attached to the other component or there may be an intervening component. When a component is said to be "connected to" another component, it can be directly connected to the other component or there may be an intervening component.

[0049] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the specification of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0050] Please see Figure 1 and Figure 2This application provides a charging circuit 10 in one embodiment. The charging circuit 10 is applied to a charging pile 20. The charging circuit 10 includes a signal circuit 100, an energy storage circuit 200, and a filter circuit 300. The signal circuit 100 is used to output a square wave signal with an adjustable duty cycle. The square wave signal is output to the load 101 to be charged through the charging gun 21 on the charging pile 20. The rise time of the square wave signal is within 2 microseconds. The first terminal of the energy storage circuit 200 is connected to the output terminal of the signal circuit 100. The second terminal of the energy storage circuit 200 is grounded. The first terminal of the filter circuit 300 is used to connect to a power supply 301. The power supply 301 is connected to the load 101 to be charged through the charging gun 21 on the charging pile 20. The second terminal of the filter circuit 300 is grounded. When the load 101 receives the square wave signal, it determines the maximum charging current value based on the square wave signal, and obtains the electrical energy provided by the power supply 301 through the charging gun 21 on the charging pile 20 according to the maximum charging current value.

[0051] In some embodiments, the specific circuit topology of the signal circuit 100 is not limited, as long as it has the function of outputting a square wave signal with an adjustable duty cycle. For example, the signal circuit 100 can be a PWM signal source or a rectangular wave signal source.

[0052] In some embodiments, the specific circuit topology of the energy storage circuit 200 is not limited, as long as it has the function of delaying the rising edge time of the square wave signal. For example, the energy storage circuit 200 can be a capacitor or an inductor. In this embodiment, the energy storage circuit 200 can adjust the rising edge time of the square wave signal, thereby avoiding the problem of conducted interference caused by an excessively fast rising edge time of the square wave signal. It should be noted that the rising edge time of the square wave signal needs to be controlled within 2 microseconds, that is, the rising edge time of the square wave signal in a single cycle needs to be controlled within 2 microseconds. This can avoid affecting subsequent operations and improve reliability.

[0053] In some embodiments, the specific circuit topology of the filter circuit 300 is not limited, as long as it has the filtering function. For example, the filter circuit 300 can use capacitor filtering or a combination of capacitor and resistor for filtering. In this embodiment, by adding the filter circuit 300 to the output side of the power supply, low-frequency interference can be absorbed, improving the anti-interference capability of the signal during transmission.

[0054] In practical use, the charging pile 20 transmits the square wave signal to the load 101 to be charged through the charging gun. This process can be achieved by adjusting the rise time of the square wave signal through the energy storage circuit 200, thereby avoiding conducted interference caused by an excessively fast rise time. The load 101 to be charged determines the maximum charging current value based on the duty cycle of the square wave signal and obtains the electrical energy provided by the power supply 301 transmitted from the charging gun 21 based on the maximum charging current value. During charging, the low-frequency interference transmitted from the output side of the power supply can be absorbed by the filter circuit 300, thereby improving the anti-interference capability of the charging process.

[0055] In some embodiments, the load to be charged 101 may be a new energy electric vehicle or a power battery of a new energy electric vehicle battery swapping station.

[0056] In some embodiments, the energy storage circuit 200 includes a first capacitor 210. A first terminal of the first capacitor 210 is connected to the output terminal of the signal circuit 100. A second terminal of the first capacitor 210 is grounded. The capacitance of the first capacitor 210 ranges from 300pF to 1600pF.

[0057] In some embodiments, the connection method between the first capacitor 210 and the output terminal of the signal circuit 100 is not limited. For example, the first capacitor 210 and the output terminal of the signal circuit 100 can be electrically connected by a wire. Specifically, the wire can be selected according to actual needs. For example, the wire can be made of copper wire or aluminum wire, etc., and no specific limitation is made here.

[0058] When the signal circuit 100 starts transmitting a square wave signal, it prioritizes charging the first capacitor 210. The square wave signal's rising edge reaches its maximum value when the first capacitor 210 is fully charged. Thus, by selecting different capacitance values ​​for the first capacitor 210, the rising edge time of the square wave signal can be adjusted. Preferably, the capacitance of the first capacitor 210 can be 1000pF.

[0059] In some embodiments, the power supply 301 is single-phase, and the filter circuit 300 includes a second capacitor 310 and a third capacitor 320. The first terminal of the second capacitor 310 is connected to the neutral wire of the single-phase power supply. The second terminal of the second capacitor 310 is grounded. The first terminal of the third capacitor 320 is connected to the live wire of the single-phase power supply. The second terminal of the third capacitor 320 is grounded.

[0060] In some embodiments, the connection method between the first terminal of the second capacitor 310 and the neutral wire of the single-phase power supply is not limited. For example, the first terminal of the second capacitor 310 and the neutral wire of the single-phase power supply can be electrically connected through a wire. Specifically, the wire can be selected according to actual needs. For example, the wire can be copper wire or aluminum wire, etc., and no specific limitation is made here.

[0061] In some embodiments, the connection method between the first terminal of the third capacitor 320 and the live wire of the single-phase power supply is not limited. For example, the first terminal of the third capacitor 320 and the live wire of the single-phase power supply can be electrically connected by a wire. Specifically, the wire can be selected according to actual needs. For example, the wire can be copper wire or aluminum wire, etc., and no specific limitation is made here.

[0062] In some embodiments, during use, the single-phase power supply can absorb low-frequency interference through the second capacitor 310 and the third capacitor 320, specifically absorbing harmonics introduced by 1kHz, thereby improving the anti-interference capability of the single-phase power supply during charging. In some embodiments, a 22nF second capacitor 310 can be added between the neutral wire and ground, and a 22nF third capacitor 320 can be added between the live wire and ground. This can further improve the anti-interference capability of the single-phase power supply during charging.

[0063] In some embodiments, the power supply 301 is a three-phase power supply, and the filter circuit 300 includes: a second capacitor 310, a third capacitor 320, a fourth capacitor 330, and a fifth capacitor 340. The first terminal of the second capacitor 310 is connected to the neutral line of the three-phase power supply. The second terminal of the second capacitor 310 is grounded. The first terminal of the third capacitor 320 is connected to the first phase line of the three-phase power supply. The second terminal of the third capacitor 320 is grounded. The first terminal of the fourth capacitor 330 is connected to the second phase line of the three-phase power supply. The second terminal of the fourth capacitor 330 is grounded. The first terminal of the fifth capacitor 340 is connected to the third phase line of the three-phase power supply. The second terminal of the fifth capacitor 340 is grounded.

[0064] In some embodiments, the connection method between the first terminal of the second capacitor 310 and the neutral wire of the three-phase power supply is not limited. For example, the first terminal of the second capacitor 310 and the neutral wire of the three-phase power supply can be electrically connected through a wire. Specifically, the wire can be selected according to actual needs. For example, the wire can be copper wire or aluminum wire, etc., and no specific limitation is made here.

[0065] In some embodiments, the connection method between the first terminal of the third capacitor 320 and the first phase line of the three-phase power supply is not limited. For example, the first terminal of the third capacitor 320 and the first phase line of the three-phase power supply can be electrically connected by a wire. Specifically, the wire can be selected according to actual needs. For example, the wire can be copper wire or aluminum wire, etc., and no specific limitation is made here.

[0066] In some embodiments, the connection method between the first terminal of the fourth capacitor 330 and the second phase line of the three-phase power supply is not limited. For example, the first terminal of the fourth capacitor 330 and the second phase line of the three-phase power supply can be electrically connected by a wire. Specifically, the wire can be selected according to actual needs. For example, the wire can be copper wire or aluminum wire, etc., and no specific limitation is made here.

[0067] In some embodiments, the connection method between the first terminal of the fifth capacitor 340 and the third phase line of the three-phase power supply is not limited. For example, the first terminal of the fifth capacitor 340 and the third phase line of the three-phase power supply can be electrically connected by a wire. Specifically, the wire can be selected according to actual needs. For example, the wire can be copper wire or aluminum wire, etc., and no specific limitation is made here.

[0068] In some embodiments, during use, the three-phase power supply can absorb low-frequency interference through the second capacitor 310, the third capacitor 320, the fourth capacitor 330, and the fifth capacitor 340, specifically absorbing harmonics introduced by 1kHz, thereby improving the anti-interference capability of the three-phase power supply during charging. In some embodiments, the second capacitor 310 with a capacity of 22nF can be added to the neutral wire to ground, and the third capacitor 320, the fourth capacitor 330, and the fifth capacitor 340 with a capacity of 22nF can be added to the three phase wires of the three-phase power supply to ground respectively. This can improve the anti-interference capability of the three-phase power supply during charging.

[0069] In some embodiments, the signal circuit 100 includes a pulse signal source 110. The pulse signal source 110 is connected to a first terminal of the energy storage circuit 200. The pulse signal source 110 is used to output a PWM signal with an adjustable duty cycle. The transmission frequency of the pulse signal source 110 is 1 kHz.

[0070] In some embodiments, the connection method between the pulse signal source 110 and the first terminal of the energy storage circuit 200 is not limited. For example, the pulse signal source 110 and the first terminal of the energy storage circuit 200 can be electrically connected by a wire. Specifically, the wire can be selected according to actual needs. For example, the wire can be made of copper wire or aluminum wire, etc., and no specific limitation is made here.

[0071] Please see Figure 3This application provides a charging pile 20 according to one embodiment. The charging pile 20 includes a charging gun 21, a charging pile body 22, and a charging circuit 10. The charging gun 21 is connected to the charging pile body 22. The charging gun 21 is used to charge a load 101 to be charged. The charging circuit 10 is disposed within the charging pile body 22.

[0072] The charging circuit 10 includes a signal circuit 100, an energy storage circuit 200, and a filter circuit 300. The signal circuit 100 outputs a square wave signal with an adjustable duty cycle. The square wave signal is output to the load 101 to be charged via the charging gun 21. The rise time of the square wave signal is within 2 microseconds. The first terminal of the energy storage circuit 200 is connected to the output terminal of the signal circuit 100. The second terminal of the energy storage circuit 200 is grounded. The first terminal of the filter circuit 300 is connected to a power supply 301. The power supply 301 is connected to the load 101 to be charged via the charging gun 21. The second terminal of the filter circuit 300 is grounded. When the load 101 receives the square wave signal, it determines the maximum charging current value based on the square wave signal and obtains the electrical energy provided by the power supply 301 through the charging gun 21 according to the maximum charging current value.

[0073] In some embodiments, the connection method between the charging gun 21 and the charging pile body 22 is not limited. For example, the charging gun 21 and the charging pile body 22 can be electrically connected via a standard charging gun wire. Specifically, the wire can be selected according to actual needs; for example, the wire can be made of copper wire, etc., and no specific limitation is made here.

[0074] In some embodiments, the fixing method of the charging circuit 10 within the charging pile body 22 is not limited. For example, the charging circuit 10 can be fixed within the charging pile body 22 by a fixing element that secures the circuit board printed with the charging circuit 10. Specifically, the fixing element can be selected according to actual needs; for example, the fixing element can be a screw or a clip, etc., and no specific limitation is made here. In some embodiments, the specific circuit topology of the signal circuit 100 can be referred to the above embodiments, and will not be repeated here.

[0075] In practical use, the charging pile body 22 transmits the square wave signal to the load 101 to be charged through the charging gun 21. This process allows the energy storage circuit 200 to adjust the rise time of the square wave signal, thereby avoiding conducted interference caused by an excessively fast rise time. The load 101 to be charged determines the maximum charging current value based on the duty cycle of the square wave signal, and obtains the electrical energy provided by the power supply 301 transmitted from the charging pile body 22 through the charging gun 21 based on the maximum charging current value. During charging, the low-frequency interference transmitted from the output side of the power supply can be absorbed by the filter circuit 300, thereby improving the anti-interference capability of the charging process.

[0076] In some embodiments, the energy storage circuit 200 includes a first capacitor 210. A first terminal of the first capacitor 210 is connected to the output terminal of the signal circuit 100. A second terminal of the first capacitor 210 is grounded. The capacitance of the first capacitor 210 ranges from 300pF to 1600pF. When the signal circuit 100 starts transmitting a square wave signal, it prioritizes charging the first capacitor 210. When the first capacitor 210 is fully charged, the rising edge of the square wave signal reaches its maximum value. Thus, by selecting the first capacitor 210 with different capacitance values, the rising edge time of the square wave signal can be adjusted. Preferably, the capacitance of the first capacitor 210 can be 1000pF.

[0077] In some embodiments, the power supply 301 is a single-phase power supply. The filter circuit 300 includes a second capacitor 310 and a third capacitor 320. The first terminal of the second capacitor 310 is connected to the neutral wire of the single-phase power supply. The second terminal of the second capacitor 310 is grounded. The first terminal of the third capacitor 320 is connected to the live wire of the single-phase power supply. The second terminal of the third capacitor 320 is grounded. In some embodiments, during use, the single-phase power supply can absorb low-frequency interference through the second capacitor 310 and the third capacitor 320, that is, absorb the harmonics introduced by 1KHz, thereby improving the anti-interference capability of the single-phase power supply during charging. In some embodiments, the second capacitor 310 with a neutral wire connected to ground and the third capacitor 320 with a live wire connected to ground can be added with a 22nF connection. This can improve the anti-interference capability of the single-phase power supply during charging.

[0078] In summary, by using the energy storage circuit 200 in conjunction with the filter circuit 300, this application can not only adjust the rise time of the square wave signal to avoid the problem of conducted interference caused by the rise time of the square wave signal being too fast, but also absorb the low-frequency interference transmitted from the output side of the power supply, thereby improving the anti-interference capability of the charging process.

[0079] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0080] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A charging circuit, characterized in that, The charging circuit, used in charging piles, includes: The signal circuit is used to output a square wave signal with an adjustable duty cycle. The square wave signal is output to the load to be charged through the charging gun on the charging pile. The rise time of the square wave signal is within 2 microseconds. An energy storage circuit, wherein a first terminal of the energy storage circuit is connected to the output terminal of the signal circuit, and a second terminal of the energy storage circuit is grounded; and A filter circuit, wherein the first terminal of the filter circuit is used to connect to a power source, the power source is connected to the load to be charged through a charging gun on the charging pile, and the second terminal of the filter circuit is grounded; When the load to be charged receives the square wave signal, it determines the maximum charging current value based on the square wave signal, and obtains the power supplied by the power source through the charging gun on the charging pile according to the maximum charging current value.

2. The charging circuit as described in claim 1, characterized in that, The energy storage circuit includes: The first capacitor has its first terminal connected to the output terminal of the signal circuit, and its second terminal grounded. The capacitance of the first capacitor ranges from 300pF to 1600pF.

3. The charging circuit as described in claim 2, characterized in that, The capacitance of the first capacitor is 1000pF.

4. The charging circuit as described in claim 1, characterized in that, The power supply is a single-phase power supply, and the filter circuit includes: The second capacitor has its first terminal connected to the neutral wire of the single-phase power supply and its second terminal grounded. The third capacitor has its first terminal connected to the live wire of the single-phase power supply, and its second terminal grounded.

5. The charging circuit as described in claim 1, characterized in that, The power supply is a three-phase power supply, and the filter circuit includes: The second capacitor has its first terminal connected to the neutral wire of the three-phase power supply and its second terminal grounded. The third capacitor has its first terminal connected to the first phase line of the three-phase power supply, and its second terminal grounded. The fourth capacitor has its first terminal connected to the second phase line of the three-phase power supply, and its second terminal grounded. The fifth capacitor has its first terminal connected to the third phase line of the three-phase power supply, and its second terminal grounded.

6. The charging circuit as described in claim 4 or 5, characterized in that, The capacitance of the second capacitor and the third capacitor is 22nF.

7. The charging circuit as described in claim 1, characterized in that, The signal circuit includes: A pulse signal source is connected to the first terminal of the energy storage circuit. The pulse signal source is used to output a PWM signal with an adjustable duty cycle. The transmission frequency of the pulse signal source is 1KHz.

8. A charging pile, characterized in that, include: The charging pile itself; A charging gun is connected to the charging pile body and is used to charge the load to be charged. as well as A charging circuit is disposed within the charging pile body; The charging circuit includes: The signal circuit is used to output a square wave signal with an adjustable duty cycle. The square wave signal is output to the load to be charged through the charging gun. The rise time of the square wave signal is within 2 microseconds. An energy storage circuit, wherein a first terminal of the energy storage circuit is connected to the output terminal of the signal circuit, and a second terminal of the energy storage circuit is grounded; A filter circuit, wherein the first terminal of the filter circuit is used to connect to a power source, the power source is connected to the load to be charged through the charging gun, and the second terminal of the filter circuit is grounded; When the load to be charged receives the square wave signal, it determines the maximum charging current value based on the square wave signal, and obtains the electrical energy provided by the power source through the charging gun according to the maximum charging current value.

9. The charging pile as described in claim 8, characterized in that, The energy storage circuit includes: The first capacitor has its first terminal connected to the output terminal of the signal circuit, and its second terminal grounded. The capacitance of the first capacitor ranges from 300pF to 1600pF.

10. The charging pile as described in claim 8, characterized in that, The power supply is a single-phase power supply, and the filter circuit includes: The second capacitor has its first terminal connected to the neutral wire of the single-phase power supply and its second terminal grounded. The third capacitor has its first terminal connected to the live wire of the single-phase power supply, and its second terminal grounded.

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