Electric leakage protection method, device, system and charging pile

Abstract

The application discloses a kind of electric leakage protection method, device, system and charging pile, electric leakage protection method includes: obtaining system distribution parameter;When the system distribution parameter meets electric leakage collection condition, obtain electric leakage value and electric leakage detection signal;According to the system distribution parameter, obtain load type;According to the electric leakage value, the electric leakage detection signal and the load type, carry out electric leakage analysis, obtain electric leakage result;The electric leakage protection action corresponding to the electric leakage result is executed, to further combine load type and electric leakage detection signal and carry out in-depth analysis, to pass through multiple levels of electric leakage judgment process, according to different electric leakage result executes different electric leakage protection action, not only improve the reliability of electric leakage protection, also improve the judgment timeliness and precision of electric leakage.

Description

Technical Field

[0001] This invention relates to the field of leakage current protection technology, and in particular to a leakage current protection method, device, system, and charging pile. Background Technology

[0002] Currently, electric vehicles are gaining increasing acceptance and popularity. However, with the continuous improvement of technical requirements for electric vehicle charging stations, it has been found that many charging stations have leakage protection that is either too sensitive or fails to activate when leakage occurs. For example, current leakage detection in charging stations relies on dedicated leakage sensors, which trigger leakage protection as soon as an abnormal electrical signal is detected, resulting in a very high false alarm rate. Summary of the Invention

[0003] This invention provides a leakage current protection method, device, system, and charging pile to solve the problem of high false alarm rate in existing leakage current protection systems.

[0004] A leakage current protection method includes:

[0005] Obtain system power distribution parameters;

[0006] When the system power distribution parameters meet the leakage current acquisition conditions, the leakage current value and leakage current detection signal are acquired.

[0007] Based on the system power distribution parameters, obtain the load type;

[0008] Based on the leakage current value, the leakage current detection signal, and the load type, leakage current analysis is performed to obtain the leakage current result;

[0009] Execute the leakage protection action corresponding to the leakage result.

[0010] Furthermore, the system power distribution parameters include system voltage and grounding signal; the leakage current acquisition condition is that the system voltage is greater than a preset voltage and the grounding signal is normal.

[0011] Further, obtaining the load type based on the system power distribution parameters includes:

[0012] Based on the system power distribution parameters, obtain the phase difference between the system voltage and the system current;

[0013] The load type is obtained based on the phase difference.

[0014] Furthermore, obtaining the load type based on the phase difference includes:

[0015] If the phase difference is positive, then the load type is an inductive load;

[0016] If the phase difference is zero, then the load type is a resistive load;

[0017] If the phase difference is negative, then the load type is capacitive load.

[0018] Further, the step of performing leakage current analysis and obtaining leakage current results based on the leakage current value, the leakage current detection signal, and the load type includes:

[0019] Based on the load type, determine the target leakage current threshold, leakage current time threshold, and insulation warning threshold;

[0020] When the leakage detection signal is a first-level signal and the first holding time of the leakage value being greater than the target leakage threshold is less than the leakage time threshold, the leakage result is determined to be a minor leakage.

[0021] If the leakage detection signal is a second-level signal and the second holding time of the leakage value being greater than the target leakage threshold is not less than the leakage time threshold, the leakage result is determined to be a severe leakage.

[0022] If the leakage current detection signal is a first-level signal and the third holding time of the leakage current value being greater than the insulation warning threshold is not less than the leakage current time threshold, the leakage current result is determined to be an abnormal insulation performance.

[0023] Further, based on the load type, the target leakage current threshold and leakage current time threshold are determined, including:

[0024] If the load type is a resistive load, the target leakage current threshold is a first leakage current threshold, and the leakage current time threshold is a first time threshold;

[0025] If the load type is an inductive load, the target leakage current threshold is the first leakage current threshold, the leakage current time threshold is the second time threshold, and the second time threshold is greater than the first time threshold;

[0026] If the load type is capacitive load, the target leakage threshold is the second leakage threshold, the leakage time threshold is the first time threshold, and the second leakage threshold is greater than the first leakage threshold.

[0027] A control device for implementing the above-described leakage current protection method.

[0028] A leakage current protection system includes a leakage current control unit, a power distribution parameter detection unit, and the aforementioned control device;

[0029] The power distribution parameter detection unit is connected to the control device and is used to collect system power distribution parameters and output the system power distribution parameters to the control device.

[0030] The leakage current control unit is connected to the control device and is used to output the leakage current value and the leakage current detection signal to the control device under the control of the control device.

[0031] Furthermore, the control device is used to output a calibration signal to the leakage current control unit;

[0032] The leakage current control unit is also used to calibrate the leakage current transformer according to the calibration signal, and obtain the leakage current value through the calibrated leakage current transformer;

[0033] The control device is also used to perform digital filtering on the leakage current value.

[0034] A charging station includes the aforementioned leakage protection system.

[0035] This invention provides a leakage current protection method, device, system, and charging pile. It acquires system power distribution parameters, and when these parameters meet leakage current acquisition conditions, acquires leakage current values ​​and leakage current detection signals to initially screen for leakage current states. Then, based on the system power distribution parameters, it acquires the load type. Based on the leakage current value, leakage current detection signal, and load type, it performs leakage current analysis to obtain leakage current results. It then executes leakage current protection actions corresponding to the leakage current results. Furthermore, it conducts in-depth analysis by combining load type and leakage current detection signal. Through a multi-level leakage current judgment process, different leakage current protection actions are executed based on different leakage current results, which not only improves the reliability of leakage current protection but also enhances the timeliness and accuracy of leakage current judgment. Attached Figure Description

[0036] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0037] Figure 1 This is a flowchart of a leakage current protection method according to an embodiment of the present invention;

[0038] Figure 2 This is another flowchart of a leakage current protection method in one embodiment of the present invention;

[0039] Figure 3 This is another flowchart of a leakage current protection method in one embodiment of the present invention;

[0040] Figure 4 This is another flowchart of a leakage current protection method in one embodiment of the present invention;

[0041] Figure 5This is another flowchart of a leakage current protection method in one embodiment of the present invention;

[0042] Figure 6 This is a schematic diagram of a leakage current protection system in one embodiment of the present invention. Detailed Implementation

[0043] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0044] It should be understood that the invention can be embodied in various forms and should not be construed as being limited to the embodiments set forth herein. Rather, providing these embodiments will make the disclosure thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

[0045] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention. When used herein, the singular forms “a,” “an,” and “the” are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms “compose” and “comprising,” when used in this specification, identify the presence of the stated features, integers, steps, operations, elements, and components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and groups. When used herein, the term “and” includes any and all combinations of the associated listed items.

[0046] To fully understand this invention, detailed structures and steps will be presented in the following description to illustrate the technical solution proposed by this invention. Preferred embodiments of the invention are described in detail below; however, in addition to these detailed descriptions, the invention may have other embodiments.

[0047] This embodiment provides a leakage current protection method applied in a charging pile. For example, as shown... Figure 6 As shown, the charging pile includes a leakage current protection system. Specifically, the leakage current protection system includes a leakage current control unit, a power distribution parameter detection unit, and a control device; the power distribution parameter detection unit, connected to the control device, is used to collect system power distribution parameters and output the system power distribution parameters to the control device; the leakage current control unit, connected to the control device, is used to output the leakage current value and leakage current detection signal to the control device under the control of the control device. The control device is used to implement this leakage current protection method.

[0048] This embodiment provides a leakage current protection method, applied in the above-mentioned control device, such as... Figure 1 As shown, it includes:

[0049] S101: Obtain system power distribution parameters.

[0050] S102: When the system power distribution parameters meet the leakage current acquisition conditions, acquire the leakage current value and leakage current detection signal.

[0051] S103: Obtain the load type based on the system power distribution parameters.

[0052] S104: Perform leakage current analysis based on leakage current value, leakage current detection signal, and load type to obtain leakage current results.

[0053] S105: Execute the leakage protection action corresponding to the leakage result.

[0054] The system power distribution parameters refer to the power distribution parameters of the leakage current protection system. Optionally, the system power distribution parameters include system voltage, system current, and grounding signal. Understandably, the grounding signal is a grounding continuity signal. Leakage current acquisition conditions are custom-set conditions used to determine whether to acquire leakage current signals. Load type refers to the type of electrical load connected to the charging pile. For example, load types include resistive loads, inductive loads, and capacitive loads. For example, resistive loads include purely resistive loads such as resistors and heaters. Inductive loads include compressors, relays, and inductive ballasts. Capacitive loads include filter capacitors and power system compensation devices. Leakage current protection actions include leakage current alarms, controlling the charging pile to stop charging and discharging, and warnings of abnormal insulation performance in the charging and discharging environment.

[0055] As an example, in step S101, the control device acquires system power distribution parameters. These system power distribution parameters can be obtained through a power distribution parameter detection unit. Exemplarily, this power distribution parameter detection unit includes a voltage and current measurement module and a ground continuity detection module. The voltage and current measurement module is used to measure the system voltage and system current. The ground continuity detection module is used to detect grounding signals. It is understood that the voltage and current measurement module and the ground continuity detection module can be implemented using techniques known to those skilled in the art, and are not limited herein.

[0056] As an example, in step S102, when the system power distribution parameters meet the leakage current acquisition conditions, the leakage current value and leakage current detection signal are acquired. In this example, when the control device determines that the system power distribution parameters meet the leakage current acquisition conditions, it controls the leakage current control unit to detect the leakage current value and leakage current detection signal. Exemplarily, the leakage current control unit includes a calibration module, an I / O detection module, and a communication module. The calibration module is used to calibrate the leakage current transformer. The communication module is used to acquire the current real-time leakage current value of the leakage current transformer. The I / O detection module is used to output a leakage current detection signal, for example, outputting a high-level signal when there is leakage and a low-level signal when there is no leakage. That is, when the system power distribution parameters meet the leakage current acquisition conditions, the control device controls the leakage current control unit to acquire the current real-time leakage current value of the leakage current transformer, controls it to perform preliminary leakage current detection, and sends the leakage current value and leakage current detection signal to the control device. It can be understood that the preliminary leakage current detection can be implemented by the hardware circuit in the I / O detection unit. It should be noted that the hardware circuit for the preliminary leakage current detection can adopt techniques known in the art, and is not limited here.

[0057] As an example, in step S103, the load type is obtained based on the system power distribution parameters. Exemplarily, the load type can be determined based on the system voltage and system current in the system power distribution parameters. In this example, since different load types have varying degrees of impact on leakage current values, obtaining the load type helps improve the accuracy of subsequent leakage current analysis.

[0058] As an example, in step S104, leakage current analysis is performed based on the leakage current value, leakage current detection signal, and load type to obtain the leakage current result. For instance, based on the load type, a leakage current judgment method is determined for different load types, and then the current leakage current severity is determined by combining the leakage current value and the leakage current detection signal. For example, different leakage current judgment thresholds and leakage current anomaly retention times are determined based on different load types, and then the leakage current severity and whether a false alarm has occurred are determined by combining the leakage current judgment threshold and the leakage current anomaly retention time.

[0059] As an example, in step S105, the leakage protection action corresponding to the leakage result is executed. Exemplarily, if the leakage result is not a minor leakage, an alarm is triggered but no other action is taken. If the leakage result is a severe leakage, an alarm is triggered and charging / discharging is stopped simultaneously. If the leakage result indicates abnormal insulation performance, an early warning is issued to remind the user of the abnormal insulation performance of the charging / discharging environment. Exemplarily, this alarm method can be triggered via indicator lights or audio devices.

[0060] In this embodiment, system power distribution parameters are acquired. When the system power distribution parameters meet the leakage current acquisition conditions, leakage current value and leakage current detection signal are acquired to initially screen out leakage current status. Then, based on the system power distribution parameters, the load type is acquired. Based on the leakage current value, leakage current detection signal, and load type, leakage current analysis is performed to obtain leakage current results. The leakage current protection action corresponding to the leakage current result is executed. This allows for further in-depth analysis by combining load type and leakage current detection signal. Through a multi-level leakage current judgment process, different leakage current protection actions are executed based on different leakage current results, which not only improves the reliability of leakage current protection but also enhances the timeliness and accuracy of leakage current judgment.

[0061] In one embodiment, the system power distribution parameters include system voltage and grounding signal; the leakage current acquisition condition is that the system voltage is greater than a preset voltage and the grounding signal is normal.

[0062] The preset voltage is a custom-set voltage. Preferably, the preset voltage is 85V.

[0063] For example, the control device collects the system voltage through the power distribution parameter detection unit and then makes a judgment. If the system voltage is less than or equal to 85V, it is judged that the system power supply is abnormal and leakage judgment is not performed; or, the power distribution parameter detection unit collects and detects the grounding system connection status. If the grounding signal is abnormal, leakage judgment is not performed.

[0064] In this embodiment, by using the leakage current acquisition conditions that the system voltage is greater than the preset voltage and the grounding signal is normal, the leakage current status can be initially screened to determine whether it is a hardware failure or a leakage in the power distribution system.

[0065] In one embodiment, such as Figure 2 As shown, in step S103, the load type is obtained based on the system power distribution parameters, including:

[0066] S201: Obtain the phase difference between system voltage and system current based on system power distribution parameters.

[0067] S202: Obtain the load type based on the phase difference.

[0068] As an example, in step S201, the phase difference between the system voltage and the system current is obtained based on the system power distribution parameters. The control device calculates the phase difference between the system voltage and the system current based on the system voltage and system current in the system power distribution parameters to obtain the phase difference between the system voltage and the system current. Exemplarily, the phase difference between the system voltage and the system current can be obtained by zero-crossing detection or Fourier transform.

[0069] As an example, in step S202, the load type is obtained based on the phase difference. In this embodiment, since different types of electrical loads will result in different phase differences between the system voltage and the system current, obtaining the load type based on the phase difference can ensure the accuracy of the load type.

[0070] In this embodiment, the phase difference between the system voltage and the system current is obtained based on the system power distribution parameters. S202: Based on the phase difference, the load type is obtained, ensuring the accuracy of the load type.

[0071] In one embodiment, such as Figure 3 As shown, in step S202, obtaining the load type based on the phase difference includes:

[0072] S301: If the phase difference is positive, the load type is inductive load.

[0073] S302: If the phase difference is zero, the load type is resistive load.

[0074] S303: If the phase difference is negative, the load type is capacitive load.

[0075] As an example, in step S301, if the phase difference is positive, the load type is an inductive load. When the load type is an inductive load, the phase of the system current lags behind the system voltage by 90 degrees. Therefore, the phase difference between the system voltage and the system current is positive.

[0076] As an example, in step S302, if the phase difference is zero, the load type is a resistive load. When the load type is a resistive load, the phase of the system current is equal to the system voltage. Therefore, the phase difference between the system voltage and the system current is zero.

[0077] As an example, in step S303, if the phase difference is negative, the load type is capacitive. When the load type is capacitive, the phase of the system current leads the system voltage by 90 degrees. Therefore, the phase difference between the system voltage and the system current is negative.

[0078] In this embodiment, if the phase difference is positive, the load type is inductive. If the phase difference is zero, the load type is resistive. If the phase difference is negative, the load type is capacitive, to ensure the accuracy of the load type.

[0079] In one embodiment, such as Figure 4 As shown, leakage current analysis is performed based on the leakage current value, leakage current detection signal, and load type to obtain leakage current results, including:

[0080] S401: Determine the target leakage current threshold, leakage current time threshold, and insulation warning threshold based on the load type.

[0081] S402: When the leakage detection signal is a first-level signal and the first holding time of the leakage value being greater than the target leakage threshold is less than the leakage time threshold, the leakage result is determined to be a minor leakage.

[0082] S403: When the leakage current detection signal is a second-level signal and the second holding time of the leakage current value is greater than the target leakage current threshold is not less than the leakage current time threshold, the leakage current result is determined to be a serious leakage current.

[0083] S404: When the leakage current detection signal is a first-level signal and the third holding time of the leakage current value being greater than the insulation warning threshold is not less than the leakage current time threshold, the leakage current result is determined to be an abnormal insulation performance.

[0084] As an example, in step S401, the target leakage current threshold, leakage current time threshold, and insulation warning threshold are determined according to the load type. Different target leakage current thresholds, leakage current time thresholds, and insulation warning thresholds are preset according to different load types.

[0085] As an example, in step S402, when the leakage detection signal is a first-level signal and the first holding time for the leakage value greater than the target leakage threshold is less than the leakage time threshold, the leakage result is determined to be a minor leakage. The IO detection module initially detects no leakage and outputs a low-level signal. However, if the leakage value is greater than the target leakage threshold, and the holding time for the leakage value greater than the target leakage threshold (i.e., the first holding time) is less than the leakage time threshold, the leakage result is determined to be a minor leakage. If the leakage detection signal is a low-level signal and the first holding time for the leakage value greater than the target leakage threshold is less than 5 seconds, the leakage result is determined to be a minor leakage.

[0086] As an example, in step S403, if the leakage detection signal is a second-level signal and the second holding time for the leakage value greater than the target leakage threshold is not less than the leakage time threshold, the leakage result is determined to be a severe leakage. The IO detection module initially detects leakage and outputs a high-level signal. However, if the leakage value is greater than the target leakage threshold and the holding time for the leakage value greater than the target leakage threshold (i.e., the second holding time) is not less than the leakage time threshold, the leakage result is determined to be a severe leakage. If the leakage detection signal is a high-level signal and the second holding time for the leakage value greater than the target leakage threshold is equal to or greater than 5 seconds, the leakage result is determined to be a severe leakage.

[0087] As an example, in step S404, when the leakage detection signal is a first-level signal and the third holding time for the leakage value being greater than the insulation warning threshold is not less than the leakage time threshold, the leakage result is determined to be an insulation performance abnormality. For example, the insulation warning threshold is 80% of the target leakage threshold. For example, when the IO detection module initially detects no leakage and outputs a low-level signal, if the real-time leakage value is greater than 80% of the target leakage threshold and the corresponding third duration is greater than the leakage time threshold, the control device determines the leakage result to be an insulation performance abnormality, thus providing an early warning to remind the user of an insulation performance abnormality warning during charging and discharging.

[0088] In this embodiment, a target leakage current threshold, a leakage current time threshold, and an insulation warning threshold are determined based on the load type. When the leakage current detection signal is at a first-level signal and the leakage current value is greater than the target leakage current threshold, and the first holding time is less than the leakage current time threshold, the leakage result is determined to be a minor leakage. When the leakage current detection signal is at a second-level signal and the leakage current value is greater than the target leakage current threshold, and the second holding time is not less than the leakage current time threshold, the leakage result is determined to be a severe leakage. When the leakage current detection signal is at a first-level signal and the leakage current value is greater than the insulation warning threshold, and the third holding time is not less than the leakage current time threshold, the leakage result is determined to be an insulation performance abnormality. Through a multi-level leakage current judgment process, and by performing leakage current analysis from different dimensions using the target leakage current threshold, leakage current time threshold, and insulation warning threshold, not only is the reliability of leakage current protection improved, but the timeliness and accuracy of leakage current judgment are also enhanced.

[0089] In one embodiment, such as Figure 5 As shown, in step S401, the target leakage current threshold and leakage current time threshold are determined according to the load type, including:

[0090] S501: If the load type is resistive load, the target leakage current threshold is the first leakage current threshold and the leakage current time threshold is the first time threshold.

[0091] S502: If the load type is an inductive load, the target leakage current threshold is the first leakage current threshold, the leakage current time threshold is the second time threshold, and the second time threshold is greater than the first time threshold.

[0092] S503: If the load type is capacitive load, the target leakage current threshold is the second leakage current threshold, the leakage current time threshold is the first time threshold, and the second leakage current threshold is greater than the first leakage current threshold.

[0093] As an example, the first leakage current threshold is increased by 10% to form the second leakage current threshold. The first time threshold is 5 seconds. The second time threshold is 10 seconds.

[0094] In this embodiment, the target leakage current threshold and leakage current time threshold are adjusted according to different load types to facilitate self-correction of leakage current value deviations caused by inductive and capacitive loads, thereby ensuring the accuracy of leakage current judgment.

[0095] This embodiment provides a control device for implementing the above-described leakage protection method.

[0096] This embodiment provides a leakage current protection system, including a leakage current control unit, a power distribution parameter detection unit, and the aforementioned control device; the power distribution parameter detection unit is connected to the control device and is used to collect system power distribution parameters and output system power distribution parameters to the control device; the leakage current control unit is connected to the control device and is used to output leakage current value and leakage current detection signal to the control device under the control of the control device.

[0097] Furthermore, the power distribution parameter detection unit includes a voltage and current measurement module and a grounding continuity detection module. The voltage and current measurement module is used to measure the system voltage and system current. The grounding continuity detection module is used to detect grounding signals. It is understood that the voltage and current measurement module and the grounding continuity detection module can be implemented using techniques known to those skilled in the art, and no limitations are imposed herein.

[0098] Furthermore, the leakage current control unit includes a calibration module, an I / O detection module, and a communication module. The calibration module is used to calibrate the leakage current transformer. The communication module is used to acquire the current real-time leakage current value of the leakage current transformer. The I / O detection module is used to output a leakage current detection signal.

[0099] Furthermore, the control device outputs a calibration signal to the leakage current control unit; the leakage current control unit is also used to calibrate the leakage current transformer according to the calibration signal, and obtain the leakage current value through the calibrated leakage current transformer; the control device is also used to perform digital filtering processing on the leakage current value. In this embodiment, the accuracy of leakage current detection can be further ensured through leakage current transformer calibration and digital filtering of the leakage current value.

[0100] Furthermore, the control device is also used to store leakage data to facilitate troubleshooting of leakage faults.

[0101] This embodiment provides a charging pile, including the aforementioned leakage protection system.

[0102] The above-described embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention 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 the present invention, and should all be included within the protection scope of the present invention.

Claims

1. A leakage current protection method, characterized in that, include: Obtain system power distribution parameters; the system power distribution parameters include system voltage and grounding signal; When the system power distribution parameters meet the leakage current acquisition conditions, the leakage current value and leakage current detection signal are acquired; the leakage current acquisition conditions are that the system voltage is greater than the preset voltage and the grounding signal is normal. Based on the system power distribution parameters, obtain the phase difference between the system voltage and the system current; The load type is obtained based on the phase difference; Based on the leakage current value, the leakage current detection signal, and the load type, leakage current analysis is performed to obtain the leakage current result; Execute the leakage protection action corresponding to the leakage result; The step of performing leakage current analysis and obtaining leakage current results based on the leakage current value, the leakage current detection signal, and the load type includes: Based on the load type, determine the target leakage current threshold, leakage current time threshold, and insulation warning threshold; When the leakage detection signal is a first-level signal and the first holding time of the leakage value being greater than the target leakage threshold is less than the leakage time threshold, the leakage result is determined to be a minor leakage. If the leakage detection signal is a second-level signal and the second holding time of the leakage value being greater than the target leakage threshold is not less than the leakage time threshold, the leakage result is determined to be a severe leakage. If the leakage current detection signal is a first-level signal and the third holding time of the leakage current value being greater than the insulation warning threshold is not less than the leakage current time threshold, the leakage current result is determined to be an abnormal insulation performance.

2. The leakage current protection method as described in claim 1, characterized in that, The step of obtaining the load type based on the phase difference includes: If the phase difference is positive, then the load type is an inductive load; If the phase difference is zero, then the load type is a resistive load; If the phase difference is negative, then the load type is capacitive load.

3. The leakage current protection method as described in claim 1, characterized in that, Based on the load type, the target leakage current threshold and leakage current time threshold are determined, including: If the load type is a resistive load, the target leakage current threshold is a first leakage current threshold, and the leakage current time threshold is a first time threshold; If the load type is an inductive load, the target leakage current threshold is the first leakage current threshold, the leakage current time threshold is the second time threshold, and the second time threshold is greater than the first time threshold; If the load type is capacitive load, the target leakage threshold is the second leakage threshold, the leakage time threshold is the first time threshold, and the second leakage threshold is greater than the first leakage threshold.

4. A control device, characterized in that, Used to implement the leakage current protection method as described in any one of claims 1 to 3.

5. A leakage current protection system, characterized in that, It includes a leakage current control unit, a power distribution parameter detection unit, and the control device as described in claim 4; The power distribution parameter detection unit is connected to the control device and is used to collect system power distribution parameters and output the system power distribution parameters to the control device. The leakage current control unit is connected to the control device and is used to output the leakage current value and the leakage current detection signal to the control device under the control of the control device.

6. The leakage current protection system as described in claim 5, characterized in that, The control device is used to output a calibration signal to the leakage current control unit; The leakage current control unit is also used to calibrate the leakage current transformer according to the calibration signal, and obtain the leakage current value through the calibrated leakage current transformer; The control device is also used to perform digital filtering on the leakage current value.

7. A charging pile, characterized in that, Including the leakage current protection system as described in claim 5 or 6.

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