Electric leakage detection method, device, equipment, medium and program product

Abstract

The embodiment of the invention discloses an electric leakage detection method, device and equipment, a medium and a program product. Comprising the steps of obtaining a to-be-processed signal in an electric leakage judgment period; determining every two adjacent peak left edge points as a peak left edge point group, and determining waveform peak points in each peak left edge point group and a relative position relationship between the waveform peak points and the corresponding peak left edge points and the corresponding peak right edge points; determining a slope value corresponding to the peak left edge point group according to the relative position relationship between the waveform peak point in each peak left edge point group and the corresponding peak left edge point and the corresponding peak right edge point, and the analog-to-digital conversion value of each sampling point in the peak left edge point group; according to each slope value and a preset slope threshold value, determining a leakage waveform from the correction waveform corresponding to each peak left edge point group; and determining an electric leakage detection result according to the distribution condition of each electric leakage waveform in the electric leakage judgment period. And the stability and universality of electric leakage detection are improved.

Description

Technical Field

[0001] This invention relates to the field of electricity monitoring technology, and in particular to a leakage current detection method, device, equipment, medium, and program product. Background Technology

[0002] A DC-AC inverter is a power conversion device that converts direct current (DC) into alternating current (AC). During operation, due to equipment aging or operational errors, the AC output live wire (L line) or neutral wire (N line) of the DC-AC inverter may be short-circuited to ground, leading to leakage current and endangering equipment and personal safety. Therefore, leakage current detection of DC-AC inverters is necessary to detect leakage current in a timely manner. Summary of the Invention

[0003] This invention provides a leakage current detection method, device, equipment, medium, and program product. By directly detecting the signal output by the DC-AC inverter during the leakage current determination period, and determining the possible leakage current waveform during the leakage current determination period based on the detected characteristic parameters, the invention achieves the detection of leakage current in the DC-AC inverter.

[0004] In a first aspect, embodiments of the present invention provide a leakage current detection method, comprising:

[0005] Acquire the signals to be processed within the leakage current determination period;

[0006] The peak points of the waveform within the leakage current determination period are determined based on the signal to be processed, as well as the left and right edge points of the peaks corresponding to each peak point.

[0007] Each pair of adjacent left edge points of the peak is defined as a group of left edge points of the peak. The peak points of the waveform within each group of left edge points of the peak are determined, as well as the relative positional relationship between the peak points of the waveform and the corresponding left and right edge points of the peak.

[0008] Based on the relative positional relationship between the waveform peak points and the corresponding left and right edge points within each peak left edge point group, and the analog-to-digital conversion value of each sampling point in the peak left edge point group, determine the slope value corresponding to the peak left edge point group.

[0009] Based on each slope value and the preset slope threshold, the leakage current waveform is determined from the corrected waveform corresponding to the left edge point group of each peak;

[0010] The leakage detection result is determined based on the distribution of each leakage waveform within the leakage determination period.

[0011] Optionally, based on each slope value and a preset slope threshold, the leakage current waveform is determined from the corrected waveform corresponding to the left edge point group of each peak, including:

[0012] The corrected waveform corresponding to the left edge point group of the peak whose slope value meets the preset slope judgment condition is determined as the leakage current waveform.

[0013] Optionally, the peak points of the waveform within the leakage current determination period are determined based on the signal to be processed, as well as the left and right edge points of each peak point, including:

[0014] The analog-to-digital conversion value of each sampling point within the leakage current determination period is determined based on the signal to be processed, and the analog-to-digital conversion difference between each adjacent sampling point is determined; the analog-to-digital conversion difference is the difference between the analog-to-digital conversion value of the sampling point with the later sampling time and the analog-to-digital conversion value of the sampling point with the earlier sampling time among adjacent sampling points;

[0015] When the sign of two adjacent analog-to-digital conversion differences changes from positive to negative, and the sign of the first preset number of analog-to-digital conversion differences after the two adjacent analog-to-digital conversion differences is negative, the overlapping sampling points among the sampling points corresponding to the two adjacent analog-to-digital conversion differences are determined as candidate waveform peak points.

[0016] If the peak value of the candidate waveform peak point is greater than the preset effective peak value threshold, then the candidate waveform peak point is determined as the waveform peak point within the leakage current determination period;

[0017] For each waveform peak point, a first target analog-to-digital conversion difference corresponding to the waveform peak point is determined, and the sampling point with the later sampling time among the sampling points corresponding to the first target analog-to-digital conversion difference is determined as the left edge point of the peak corresponding to the waveform peak point; the first target analog-to-digital conversion difference is the first analog-to-digital conversion difference that is greater than the preset difference threshold located before the waveform peak point;

[0018] For each waveform peak point, determine the second target analog-to-digital conversion difference corresponding to the waveform peak point, and determine the sampling point with the earlier sampling time among the sampling points corresponding to the second target analog-to-digital conversion difference as the right edge point of the peak corresponding to the waveform peak point; the second target analog-to-digital conversion difference is the first analog-to-digital conversion difference located after the waveform peak point whose absolute value is greater than the preset difference threshold.

[0019] Optionally, based on the relative positional relationship between the waveform peak points and the corresponding left and right edge points within each peak left edge point group, and the analog-to-digital conversion value of each sampling point in the peak left edge point group, the slope value corresponding to the peak left edge point group is determined, including:

[0020] When the distance between the peak point of the waveform and the corresponding left edge point within the left edge point group is less than the distance between the peak point and the corresponding right edge point, the slope value corresponding to the left edge point group is determined based on the analog-to-digital conversion values ​​of each sampling point between the peak point and the right edge point; where the slope value corresponding to the left edge point group is negative.

[0021] When the distance between the peak point of the waveform and the corresponding left edge point in the left edge point group is greater than the distance between the peak point and the corresponding right edge point, the slope value corresponding to the left edge point group is determined based on the analog-to-digital conversion value of each sampling point between the left edge point and the peak point of the waveform; wherein, the slope value corresponding to the left edge point group is a positive value.

[0022] Optionally, when the slope value is negative, the preset slope determination condition is that the slope value is less than a preset slope threshold;

[0023] When the slope value is positive, the preset slope determination condition is that the slope value is greater than the preset slope threshold;

[0024] The preset slope threshold takes different values ​​depending on the sign value corresponding to the slope value.

[0025] Optionally, the leakage current detection result is determined based on the distribution of each leakage current waveform within the leakage current determination period, including at least one of the following:

[0026] When the number of consecutive occurrences of each leakage waveform within the leakage judgment period exceeds the second preset number, the existence of leakage phenomenon will be determined as a leakage detection result.

[0027] When the number of occurrences of each leakage waveform within the leakage judgment period exceeds the third preset number, the existence of leakage phenomenon will be determined as a leakage detection result.

[0028] Optionally, the signal to be processed is the AC voltage output by the inverter, which is rectified and converted to obtain a correction wave signal; the leakage current determination period includes multiple correction wave periods.

[0029] Optionally, the signal to be processed is constructed from multiple sampling points obtained by sampling at fixed sampling intervals.

[0030] Secondly, embodiments of the present invention also provide a leakage current detection device, including a processor and a memory connected to the processor. The memory stores signal acquisition program code, key point determination program code, position relationship determination program code, slope value determination program code, leakage current waveform determination program code, and detection result determination program code.

[0031] The processor is configured to execute signal acquisition program code to acquire signals to be processed within the leakage current determination period;

[0032] The processor is also configured to execute key point determination code to determine the waveform peak points within the leakage current determination period based on the signal to be processed, as well as the left and right edge points of each waveform peak point.

[0033] The processor is also configured to execute positional relationship determination code to determine every two adjacent left edge points of the peak as a group of left edge points of the peak, determine the peak points of the waveform within each group of left edge points of the peak, and the relative positional relationship between the peak points of the waveform and the corresponding left and right edge points of the peak.

[0034] The processor is also configured to execute slope value determination code to determine the slope value corresponding to the left edge point group based on the relative positional relationship between the waveform peak point and the corresponding left and right edge points within each left edge point group, and the analog-to-digital conversion value of each sampling point in the left edge point group.

[0035] The processor is also configured to execute leakage waveform determination program code to determine the leakage waveform from the corrected waveform corresponding to each peak left edge point group based on each slope value and a preset slope threshold.

[0036] The processor is also configured to execute detection result determination code to determine the leakage detection result based on the distribution of each leakage waveform within the leakage determination period.

[0037] Thirdly, embodiments of the present invention also provide a leakage current detection device, comprising:

[0038] At least one processor;

[0039] and a memory communicatively connected to at least one processor; wherein,

[0040] The memory stores a computer program that can be executed by at least one processor, such that the at least one processor is able to perform the leakage current detection method of any embodiment of the present invention.

[0041] Fourthly, embodiments of the present invention also provide a storage medium containing computer-executable instructions, which, when executed by a computer processor, are used to perform the leakage current detection method provided in any of the above embodiments.

[0042] Fifthly, embodiments of the present invention also provide a computer program product, including a computer program that, when executed by a processor, implements the leakage current detection method provided in any of the above embodiments.

[0043] This invention provides a leakage current detection method, apparatus, device, medium, and program product. The method involves: acquiring a signal to be processed within a leakage current determination period; determining the waveform peak points within the leakage current determination period based on the signal to be processed, as well as the corresponding left and right edge points of each waveform peak point; defining each pair of adjacent left edge points as a left edge point group; determining the waveform peak points within each left edge point group, and the relative positional relationship between the waveform peak points and their corresponding left and right edge points; determining the slope value corresponding to the left edge point group based on the relative positional relationship between the waveform peak points within each left edge point group and their corresponding left and right edge points, and the analog-to-digital conversion value of each sampling point in the left edge point group; determining the leakage current waveform from the corrected waveform corresponding to each left edge point group based on each slope value and a preset slope threshold; and determining the leakage current detection result based on the distribution of each leakage current waveform within the leakage current determination period. By adopting the above technical solution, the signal to be processed output by the DC-AC inverter is directly collected during the leakage current determination period. Based on the characteristic parameters such as the peak point, left edge point and right edge point of the waveform determined by the collected signal to be processed, the leakage current waveform that may exist during the leakage current determination period is determined. Then, based on the distribution of each leakage current waveform during the leakage current determination period, the leakage current in the DC-AC inverter can be detected.

[0044] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of this application, nor is it intended to limit the scope of this application. Other features of this application will become readily apparent from the following description. Attached Figure Description

[0045] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying 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.

[0046] Figure 1 A flowchart of a leakage current detection method provided in an embodiment of the present invention;

[0047] Figure 2 An example diagram of the AC port output voltage waveform of a DC-AC inverter provided in an embodiment of the present invention;

[0048] Figure 3 An example waveform diagram of a correction wave signal during normal operation of a DC-AC inverter provided in an embodiment of the present invention;

[0049] Figure 4This is an example waveform diagram of a correction wave signal when leakage current exists in a DC-AC inverter, provided by an embodiment of the present invention.

[0050] Figure 5 This is an example diagram of the correction wave signal waveform when leakage current exists in another DC-AC inverter provided by an embodiment of the present invention;

[0051] Figure 6 This is an example diagram of the correction wave signal waveform when leakage current exists in another DC-AC inverter provided by an embodiment of the present invention;

[0052] Figure 7 This is a flowchart illustrating an embodiment of the present invention for determining the waveform peak point within a leakage current determination period based on the signal to be processed.

[0053] Figure 8 A flowchart illustrating a leakage current detection method provided in an embodiment of the present invention;

[0054] Figure 9 A flowchart illustrating a leakage current detection method provided in an embodiment of the present invention;

[0055] Figure 10 A flowchart illustrating a leakage current detection method provided in an embodiment of the present invention;

[0056] Figure 11 A flowchart illustrating a leakage current detection method provided in an embodiment of the present invention;

[0057] Figure 12 This is a schematic diagram of a leakage current detection device provided in an embodiment of the present invention;

[0058] Figure 13 This is a schematic diagram of a leakage current detection device provided in an embodiment of the present invention. Detailed Implementation

[0059] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0060] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0061] In one exemplary implementation Figure 1 This is a flowchart illustrating a leakage current detection method provided by an embodiment of the present invention. This embodiment is applicable to detecting potential leakage current faults in DC-AC inverters. The method can be executed by a leakage current detection device, which can be implemented using software and / or hardware, and can be configured within a leakage current detection equipment. Optionally, the leakage current detection device can be an electronic device, such as a laptop, desktop computer, or smart tablet, etc. This embodiment of the present invention does not impose any limitations on this.

[0062] like Figure 1 As shown in the figure, the leakage current detection method provided by the embodiment of the present invention specifically includes the following steps:

[0063] S101. Obtain the signal to be processed within the leakage current determination period.

[0064] In this embodiment, the leakage current determination period can be specifically understood as a period of time during which the processed signal output by the DC-AC inverter is collected when it is necessary to determine whether a leakage current problem exists in the DC-AC inverter. The signal to be processed can be specifically understood as the signal output by the DC-AC inverter collected within the leakage current determination period, which can be used to reflect whether a leakage current problem exists in the DC-AC inverter. Optionally, the signal to be processed can be constructed from multiple sampling points obtained by sampling at fixed sampling intervals. Optionally, the signal to be processed is the AC voltage output by the inverter, rectified and voltage converted to obtain a corrected wave signal. Specifically, the corrected wave signal can be understood as the voltage signal obtained after adjusting and correcting the AC voltage output by the inverter. Optionally, the leakage current determination period includes multiple corrected wave periods; that is, the signal to be processed acquired in one leakage current determination period will contain multiple corrected waves.

[0065] It is understandable that the AC port of a DC-AC inverter outputs an AC voltage. Although the live and neutral wires between the digital ground and the AC output port are electrically isolated, there will be a weak leakage current between the AC output port and the digital ground due to parasitic parameters in the circuit. This leakage current can be collected by the power acquisition circuit to obtain the corresponding signal. The signal to be processed proposed in this embodiment is the AC voltage signal output by the inverter relative to the digital ground, which is obtained after rectification and voltage conversion. It belongs to the corrected wave signal within the effective voltage range that the leakage current detection device can detect.

[0066] It is understood that a single point can be taken from the leakage protection circuit of the DC-AC inverter as a voltage acquisition point, and the acquisition of the signal to be processed in this embodiment of the invention can be completed using this voltage acquisition point. Since DC-AC inverters are often equipped with leakage protection circuits, this embodiment of the invention can achieve leakage detection in DC-AC inverters without the need for additional leakage detection circuits, reducing the complexity of the circuits and the amount of data processing required for leakage detection, improving the stability and versatility of leakage detection, and enabling leakage detection of DC-AC inverters to meet the detection needs under different computing power scenarios.

[0067] For example, Figure 2 An example diagram of the AC port output voltage waveform of a DC-AC inverter provided in an embodiment of the present invention is shown below. Figure 2 As shown, it presents an AC voltage signal in the form of a square wave, with alternating positive and negative half-cycles. After rectification and voltage conversion of the AC voltage signal, the negative half-cycle of the AC output waveform will be rectified to the positive half-cycle. If no leakage current problem occurs, the resulting corrected waveform will look like this. Figure 3 As shown, Figure 3 This is an example diagram of the corrected wave signal waveform during normal operation of a DC-AC inverter, provided as an embodiment of the present invention.

[0068] by Figure 3 Taking the corrected wave signal waveform during normal operation as an example, assuming the half-period of the corrected wave signal is represented by T, and assuming the corrected wave signal is constructed from multiple sampling points obtained by sampling at a fixed sampling interval, then, with a fixed sampling interval, there can be a certain correspondence between the period of the corrected wave signal and the number of sampling points. Assuming the sampling interval is represented by d, the number of sampling points between the left edges of two adjacent square waves is represented by N, and the number of sampling points at the trough is represented by H, then... Figure 3 The corrected wave signal waveform shown has the following relationship: H×d <T;N×d≈T。

[0069] Specifically, when it is necessary to detect whether there is a leakage problem in a DC-AC inverter, a period of time during the operation of the DC-AC inverter can be selected as the leakage judgment period. The AC output voltage and digital ground AC voltage signals in the DC-AC inverter are collected during the leakage judgment period. After processing the AC voltage signal, including rectification and voltage conversion, the signal to be processed during the leakage judgment period is obtained.

[0070] It is understandable that the above... Figure 3 The waveform of the corrected wave signal shown is the waveform that the corrected wave signal can present under normal operation of a DC-AC inverter. However, if the live wire or neutral wire of the inverter is shorted to ground, resulting in leakage current, the waveform output by the DC-AC inverter will change, thus altering the waveform of the processed corrected wave signal. For example, as the leakage resistance of the short circuit decreases, the slope of the wave within half a cycle will gradually increase, and the difference between adjacent peaks will also gradually increase. The specific changes in the corrected wave signal waveform are shown in the following figures. Figure 4 This is an example waveform diagram of a correction wave signal when leakage current exists in a DC-AC inverter, provided by an embodiment of the present invention. Figure 5 This is an example diagram of the correction wave signal waveform when leakage current exists in another DC-AC inverter provided by an embodiment of the present invention; Figure 6 This is an example waveform diagram of a correction wave signal when leakage current exists in another DC-AC inverter provided in an embodiment of the present invention. Wherein, Figure 4 The waveform corresponding to the slope anomaly is shown in the image. Figure 5 The waveform corresponding to this is an abnormal waveform with an excessively large difference between adjacent peaks. Figure 6 The waveform corresponding to this is an abnormal waveform with a missing half-cycle peak.

[0071] Due to such Figures 4-6 The characteristics of the abnormal correction wave signal waveform that may occur during leakage shown can be displayed by the peak point of the waveform corresponding to the correction wave signal waveform, the left edge point of the peak corresponding to the peak point, and the difference between two adjacent peak points, based on the distribution of each sampling point in the waveform. Therefore, the above information that can be used to indicate the characteristics of the abnormal correction wave signal can be extracted from the signal to be processed, and based on this, it can be determined whether there is an abnormality in each correction wave signal waveform corresponding to the signal to be processed.

[0072] S102. Based on the signal to be processed, determine at least one of the following: the peak point of the waveform within the leakage current determination period, the left edge point of each peak point, the difference between adjacent peaks, the total number of samples between adjacent left edge points, the number of samples between adjacent left edge points, the relative positional relationship between the peak point and its corresponding left and right edge points, and the analog-to-digital conversion value of each sampling point in the left edge point group.

[0073] In this embodiment, the waveform peak point can be specifically understood as the maximum value point reached by the waveform corresponding to the signal to be processed within a certain period of time during the leakage current determination period. It is understood that the leakage current determination period may contain multiple waveform peak points. If the DC-AC inverter does not have a leakage current problem, then each of the multiple correction wave periods corresponding to the leakage current determination period should contain two waveform peak points. However, in the case of a leakage current problem, the position and corresponding value of the waveform peak points may change accordingly, which can be used to determine the leakage current waveform.

[0074] In this embodiment, the left edge of the peak can be specifically understood as the point where the sampling point difference changes abruptly within the transition region to the left of the peak point during the waveform's rise from a low level to the peak point. Correspondingly, the point where the sampling point difference changes abruptly within the transition region to the right of the peak point during the waveform's fall from the peak point to a low level can be called the right edge of the peak.

[0075] In this embodiment, the relative positional relationship between the waveform peak point and its corresponding left and right edges can be understood as information indicating whether the waveform peak point is closer to its corresponding left or right edge. It can be understood that if the waveform peak point is closer to its corresponding left edge, the waveform in a descending state corresponding to the peak point is considered longer, and the slope of the waveform between the peak point and the right edge needs to be determined as the slope of that waveform. Conversely, if the waveform peak point is closer to its corresponding right edge, the waveform in an ascending state corresponding to the peak point is considered longer, and the slope of the waveform between the peak point and the left edge needs to be determined as the slope of that waveform.

[0076] In this embodiment, the analog-to-digital conversion value can be specifically understood as the value obtained by converting the voltage value, which exists in the form of an analog signal, collected at a sampling point on the left edge of the peak, into the form of a discrete digital signal.

[0077] In this embodiment, the difference between adjacent peaks can be specifically understood as the difference obtained by subtracting the values ​​corresponding to the peak points of two adjacent waveforms. The total number of samples between the left edges of adjacent peaks can be specifically understood as the total number of sampling points included when the waveform corresponding to the left edges of two adjacent waveform peaks is converted into a waveform constructed from sampling points obtained by sampling at a fixed sampling interval. The number of trough samples between adjacent left edges of adjacent peaks can be specifically understood as the number of sampling points corresponding to the trough portion of the waveform when the waveform corresponding to the left edges of two adjacent waveform peaks is converted into a waveform constructed from sampling points obtained by sampling at a fixed sampling interval. It can be understood that every two adjacent left edges of peaks can form a group of left edges of peaks, that is, each group of left edges of peaks can correspond to a total number of samples and a number of trough samples.

[0078] S103. Determine the leakage current waveform in the signal to be processed based on the peak points of each waveform, the left edge points of the peak points corresponding to each peak point, the difference between each adjacent peak, the total number of samples between each adjacent left edge points, the number of samples between each adjacent left edge points, the relative positional relationship between each peak point and its corresponding left and right edge points, and the analog-to-digital conversion value of each sampling point in each left edge point group.

[0079] Specifically, due to, as Figures 4-6 The abnormal correction wave signal waveform that may occur during leakage current, as shown, has its corresponding waveform display characteristics. These characteristics can be represented by at least one of the following: waveform peak points, the left edge points corresponding to each peak point, the difference between adjacent peaks, the total number of samples between adjacent left edge points, the number of trough samples between adjacent left edge points, the relative positional relationship between the waveform peak points and their corresponding left and right edge points, and the analog-to-digital conversion values ​​of each sample point in the left edge point group. Therefore, after clarifying the waveform peak points within the leakage current determination period, the left edge points corresponding to each peak point, the difference between adjacent peaks, the total number of samples between adjacent left edge points, the number of trough samples between adjacent left edge points, the relative positional relationship between each waveform peak point and its corresponding left and right edge points, and the analog-to-digital conversion values ​​of each sample point in each left edge point group, the above parameters can be compared with those shown below. Figures 4-6 By comparing the waveform display characteristics of the abnormal correction wave signal waveform that may occur during leakage as shown, the waveform that matches the waveform display characteristics of the waveforms corresponding to the above parameters is determined as the leakage waveform.

[0080] S104. Determine the leakage detection result based on the distribution of each leakage waveform within the leakage judgment period.

[0081] Specifically, the waveform of the signal to be processed is affected by various external factors. Some of these factors may cause occasional leakage waveforms to appear in the waveform corresponding to the signal, but this does not necessarily mean that the DC-AC inverter actually has a leakage problem during the leakage determination period. To avoid the impact of occasional or single leakage waveforms on the accuracy of leakage detection, this embodiment of the invention analyzes the distribution of multiple leakage waveforms identified during the leakage determination period to determine the final leakage detection result. That is, only when multiple leakage waveforms exist during the leakage determination period, and the distribution of each leakage waveform during the leakage determination period meets the judgment rules preset according to the actual situation, is it determined that the DC-AC inverter has a leakage problem, thus making the determined leakage detection result more accurate.

[0082] The technical solution of this embodiment directly collects the signal to be processed output by the DC-AC inverter during the leakage current determination period. Based on the characteristic parameters such as the peak point, left edge point of the peak, and number of samples determined from the collected signal, the possible leakage waveforms within the leakage current determination period are identified. Then, based on the distribution of each leakage waveform within the leakage current determination period, leakage current detection in the DC-AC inverter is achieved. During this detection process, the characteristic parameters directly extracted from the collected signal are comprehensively judged. Leakage current determination for the DC-AC inverter is achieved without adding new circuitry for leakage current detection, reducing the complexity of the circuitry and the amount of data computation required for leakage current detection. This improves the stability and versatility of leakage current detection, enabling leakage current detection for DC-AC inverters to meet the detection needs of different computing power scenarios.

[0083] Optionally, since false waveform peaks may be generated in the waveform corresponding to the signal to be processed due to environmental influences, in order to ensure the effectiveness of the waveform peak points used for abnormal waveform identification, the false waveform peaks that may be generated can be screened out when determining the waveform peak points within the leakage current determination period based on the signal to be processed. Figure 7 This is a flowchart illustrating an embodiment of the present invention for determining the waveform peak point within a leakage current determination period based on the signal to be processed. Figure 7 As shown, this can be achieved in the following way:

[0084] S201. Determine the analog-to-digital conversion value of each sampling point within the leakage current determination period based on the signal to be processed, and determine the analog-to-digital conversion difference between adjacent sampling points.

[0085] The analog-to-digital conversion difference is the difference between the analog-to-digital conversion value of the sampling point with a later sampling time and the analog-to-digital conversion value of the sampling point with a earlier sampling time among adjacent sampling points.

[0086] In this embodiment, the analog-to-digital conversion value can be specifically understood as the value obtained by converting the voltage value, which exists in the form of an analog signal, collected at a sampling point in the leakage current determination period into the form of a discrete digital signal.

[0087] Specifically, the signal to be processed acquired within the leakage current determination period can be considered as a collection of voltage signals obtained by sampling multiple times at fixed sampling intervals, with each sampling point corresponding to a sampling point. For ease of data processing and computation, the signal to be processed acquired within the leakage current determination period undergoes analog-to-digital conversion (ADC) to obtain the ADC value corresponding to each sampling point. Then, based on the sampling time corresponding to each sampling point, the difference between two adjacent sampling points with adjacent sampling times can be calculated to determine the waveform change trend between adjacent sampling points, thus obtaining the ADC difference value between adjacent sampling points. Optionally, to better reflect the waveform change trend over time, when determining the ADC difference value, the ADC value of the sampling point with the later sampling time in two adjacent sampling points can be subtracted from the ADC value of the sampling point with the earlier sampling time to obtain the corresponding ADC difference value.

[0088] S202. When the sign of two adjacent analog-to-digital conversion differences changes from positive to negative, and the sign of the first preset number of analog-to-digital conversion differences after the two adjacent analog-to-digital conversion differences is negative, the overlapping sampling points among the sampling points corresponding to the two adjacent analog-to-digital conversion differences are determined as candidate waveform peak points.

[0089] In this embodiment, the first preset quantity can be understood as a threshold number set in advance according to the actual situation, used to determine the number of sampling points whose corresponding analog-to-digital conversion values ​​continuously decrease after the peak, satisfying the waveform change pattern after the peak. Candidate waveform peak points can be understood as points in the waveform that initially meet the condition of reaching their maximum value within a certain period, but whose existence has not yet been determined as false peaks.

[0090] Specifically, based on the characteristics of waveform peaks, the analog-to-digital conversion (ADC) values ​​corresponding to each sampling point will continuously increase until the waveform peak is reached. That is, the sign of each ADC difference before the waveform peak should be positive. After reaching the waveform peak, the ADC values ​​corresponding to each sampling point will continuously decrease, exhibiting a continuous downward trend for a period of time along the falling edge of the waveform. That is, the sign of each ADC difference after the waveform peak should be negative, and a waveform peak can only be identified when multiple consecutive ADC differences are negative. Therefore, a waveform peak can be understood as the sampling point corresponding to the change of sign between two adjacent ADC differences. In other words, when the sign of two adjacent ADC differences changes from positive to negative, and the sign of the first preset number of ADC differences after the two adjacent ADC differences is negative, the sampling point that is a component of the two adjacent ADC differences is determined as a candidate waveform peak.

[0091] S203. Determine whether the peak value of the candidate waveform peak point is greater than the preset effective peak value threshold. If yes, execute S204; otherwise, execute S205.

[0092] In this embodiment, since the peak value caused by interference is often smaller than the peak value that the DC-AC inverter output voltage can reach, a value that indicates that the peak point of the waveform belongs to the peak point brought by the output voltage can be preset as a preset effective peak threshold according to the actual situation of the DC-AC inverter output AC voltage.

[0093] Specifically, by comparing the peak value of the candidate waveform peak point with a preset effective peak value threshold, it is determined whether the candidate waveform peak point belongs to the peak value brought by the DC-AC inverter output voltage. If the peak value of the candidate waveform peak point is greater than the preset effective peak value threshold, it can be considered that the candidate waveform peak point belongs to the peak value brought by the DC-AC inverter output voltage and belongs to the effective peak value in the waveform corresponding to the signal to be processed that should be considered as the basis for subsequent leakage waveform determination. At this time, S204 is executed. If the peak value of the candidate waveform peak point is not greater than the preset effective peak value threshold, it can be considered that the candidate waveform peak point does not belong to the peak value brought by the DC-AC inverter output voltage and belongs to the invalid peak value in the waveform corresponding to the signal to be processed due to interference. At this time, S205 is executed, and the interference peak value can be ignored after S205 to prevent the interference peak value from being taken into account in the subsequent leakage waveform determination process due to external factors, thus affecting the accuracy of the determination result.

[0094] S204. The peak point of the candidate waveform is determined as the peak point of the waveform within the leakage current determination period.

[0095] S205. The peak point of the candidate waveform is determined as the interference peak value within the leakage current determination period.

[0096] Optionally, after identifying multiple waveform peak points within the leakage current determination period, the left and right edge points corresponding to the waveform peak points can be determined based on the position of each peak point and the analog-to-digital conversion difference between sampling points before and after that peak point. The method for determining the left edge point is as follows:

[0097] For each waveform peak point, a first target analog-to-digital conversion difference corresponding to the waveform peak point is determined, and the sampling point with the later sampling time among the sampling points corresponding to the first target analog-to-digital conversion difference is determined as the left edge point of the peak corresponding to the waveform peak point; wherein, the first target analog-to-digital conversion difference is the first analog-to-digital conversion difference that is greater than the preset difference threshold located before the waveform peak point.

[0098] In this embodiment, the preset difference threshold can be understood as a threshold set in advance according to the actual situation, used to distinguish whether one of the two adjacent sampling points can be used as the edge point of the waveform peak point for analog-to-digital conversion difference.

[0099] Specifically, for each waveform peak, the analog-to-digital conversion (ADC) differences preceding that peak can be sequentially acquired, and the first ADC difference exceeding a preset threshold is identified as the first target ADC difference corresponding to that peak. Since the first target ADC difference is obtained by subtracting the ADC values ​​of two adjacent sampling points, the sampling point with the later sampling time among the two sampling points corresponding to the first target ADC difference can be identified as the left edge of the peak. In other words, among the two sampling points corresponding to the first target ADC difference, the sampling point with a sampling time closer to the waveform peak is identified as the left edge of the peak.

[0100] The method for determining the right edge point of the peak is as follows:

[0101] For each waveform peak point, determine the second target analog-to-digital conversion difference corresponding to the waveform peak point, and determine the sampling point with the earlier sampling time among the sampling points corresponding to the second target analog-to-digital conversion difference as the right edge point of the peak corresponding to the waveform peak point; the second target analog-to-digital conversion difference is the first analog-to-digital conversion difference located after the waveform peak point whose absolute value is greater than the preset difference threshold.

[0102] Specifically, similar to the method for determining the left edge of the peak, for each waveform peak point, the analog-to-digital conversion differences following that peak point can be obtained sequentially. The first analog-to-digital conversion difference whose absolute value is greater than a preset difference threshold is determined as the second target analog-to-digital conversion difference corresponding to that peak point. Since the second target analog-to-digital conversion difference is obtained by subtracting the analog-to-digital conversion values ​​of two adjacent sampling points, the sampling point with the earlier sampling time among the two sampling points corresponding to the second target analog-to-digital conversion difference can be determined as the right edge of the peak. In other words, among the two sampling points corresponding to the second target analog-to-digital conversion difference, the sampling point with a sampling time closer to the waveform peak point is determined as the right edge of the peak.

[0103] Understandable, Figures 4-6 The waveforms shown are all abnormal correction signals that may occur during leakage. The shapes of these abnormal correction signals differ, and the methods for determining leakage waveforms vary depending on waveform characteristics such as peak points, the left edge point corresponding to each peak point, the difference between adjacent peaks, the total number of samples between adjacent left edge points, and the number of trough samples between adjacent left edge points. A single waveform corresponding to a group of left edge points is used as the unit for determining a leakage waveform. The following sections will discuss whether the waveforms corresponding to a group of left edge points belong to... Figures 4-6 The methods for determining the waveforms of different abnormal correction wave signals are introduced below:

[0104] For example Figure 4 As shown, when the abnormal correction wave signal waveform exhibits an abnormal slope, it can be determined based on the relative positional relationship between the peak point and its corresponding left and right edge points, the analog-to-digital conversion value of each sampling point in the left edge point group, the total number of samples in the left edge point group, and the difference between adjacent peaks. To ensure the validity of the slope value determined in the waveform corresponding to the left edge point group, the slope of the waveform between the adjacent left and right edge points of the peak point is determined as the slope of the waveform. At this point, based on the relative position of the peak point and its corresponding left and right edge points, it can be determined whether the peak point is closer to the left or right edge of the waveform. If it is closer to the left edge, the waveform in a descending state is considered longer, and the slope of the waveform between the peak point and the right edge point is determined as the slope of the waveform. This can be achieved by using the analog-to-digital conversion values ​​of each sampling point from the peak point to the right edge point in the left edge point group to determine the slope value corresponding to the left edge point group. Conversely, if it is closer to the right edge, the waveform in an ascending state is considered longer, and the slope of the waveform between the left edge point and the peak point is determined as the slope of the waveform. This can also be achieved by using the analog-to-digital conversion values ​​of each sampling point from the left edge point to the peak point in the left edge point group to determine the slope value corresponding to the left edge point group.

[0105] In some examples, the slope value can be represented by the difference between the analog-to-digital conversion values ​​of each sampling point. For example, the difference between the analog-to-digital conversion values ​​of adjacent sampling points can be calculated, and the minimum difference between the analog-to-digital conversion values ​​within the range of the sampling points used to calculate the slope value can be counted and used as the slope value corresponding to the left edge point group of the peak; or the average value of the difference between the analog-to-digital conversion values ​​of each sampling point can be used as the slope value corresponding to the left edge point group of the peak. The present invention does not limit the method of determining the slope value.

[0106] Optionally, whether the waveform corresponding to the left edge point group of the peak has an abnormal slope can be determined based on its corresponding slope value and a preset slope threshold. When the corresponding slope value meets the preset slope judgment condition between the preset slope value and the preset slope threshold, the abnormal correction wave signal waveform corresponding to the left edge point group of the peak can be considered as a leakage current waveform with an abnormal slope.

[0107] Specifically, the preset slope threshold can be understood as a slope threshold pre-set according to the actual situation, used to determine whether the waveform slope is abnormal. It can be understood that if the slope value corresponding to the left edge point group of the peak is the slope value of the waveform between the left edge point of the peak and the peak point, the slope value is positive, and the corresponding preset slope threshold should also be positive; if the slope value corresponding to the left edge point group of the peak is the slope value of the waveform between the peak point and the right edge point, the slope value is negative, and the corresponding preset slope threshold should also be negative.

[0108] Accordingly, the preset slope determination conditions may include the following two cases:

[0109] When the slope value is negative, the preset slope determination condition is that the slope value is less than a preset slope threshold; when the slope value is positive, the preset slope determination condition is that the slope value is greater than the preset slope threshold. The preset slope threshold takes different values ​​depending on the sign of the slope value.

[0110] Specifically, the method for determining whether the corrected waveform corresponding to the left edge point group of the peak is a leakage waveform, based on the slope value, preset slope threshold, and preset slope judgment condition, can be as follows: When the slope value is negative, the slope value is compared with the preset slope threshold. If the slope value is less than the preset slope threshold, the preset slope judgment condition is considered met, and the corrected waveform corresponding to the left edge point group of the peak is determined to be a leakage waveform. When the slope value is positive, the slope value is compared with the preset slope threshold. If the slope value is greater than the preset slope threshold, the preset slope judgment condition is considered met, and the corrected waveform corresponding to the left edge point group of the peak is determined to be a leakage waveform.

[0111] It needs to be clarified that in a detection process that includes multiple cycles, if the leakage waveform needs to be determined based on the slope value corresponding to the left edge point group of the peak, only the slope will be taken for leakage waveform determination, or only the slope will be taken for leakage waveform determination, so that leakage waveform determination will only be performed once within the same waveform cycle consisting of positive half-cycle and negative half-cycle.

[0112] Furthermore, due to such Figure 4 The abnormal correction wave signal waveform shown is a waveform with an abnormal slope. It refers to the abnormality of the waveform within half a cycle of the correction wave signal, which means that... Figure 4 The total number of samples corresponding to the abnormal correction wave signal shown should be less than the preset number of samples per correction wave period, and should be greater than or equal to the preset threshold for the number of samples per half-cycle of the correction wave, in order to ensure that it is used to determine the presence of Figure 4 The abnormal correction wave signal waveform shown is a half-cycle signal waveform. For further definition... Figure 4 The waveform used for slope anomaly detection is a half-cycle signal waveform without other anomalies. Based on the slope value corresponding to the determined left-side edge point group of the peak, it is determined whether the corrected waveform corresponding to that left-side edge point group exists. Figure 4 When an anomaly is shown, the following can be determined first: based on the pre-defined lower limit of the number of samples for the corrected waveform period, the upper limit of the number of samples for the corrected waveform period, the threshold of the number of samples for the corrected waveform half-period, and the threshold of the peak difference, as well as the total number of samples, the number of samples at the trough, and the difference between adjacent peaks corresponding to the left edge point group of the peak, it can be determined that the waveform does not exist as shown. Figure 5 and Figure 6 The anomaly shown.

[0113] Specifically, the preset lower limit for the number of samples in the corrected wave period can be understood as a value pre-set according to the actual situation, indicating the lower limit of the number of sampling points that can be included in one corrected wave period. Optionally, the preset lower limit for the number of samples in the corrected wave period can be a value that is 4%-10% lower than the number of samples in one corrected wave period.

[0114] Specifically, the preset upper limit of the number of samples in the corrected wave period can be understood as a value pre-set according to the actual situation, indicating the upper limit of the number of sampling points that can be included in one corrected wave period. Optionally, the preset upper limit of the number of samples in the corrected wave period can be a value that is 4%-10% higher than the number of samples in one corrected wave period.

[0115] The preset threshold for the number of samples in a half-cycle of the corrected wave can be understood as a value that is preset according to the actual situation, indicating the number of sampling points that can be included in a half-cycle of the corrected wave.

[0116] The preset peak difference threshold can be understood as a threshold set in advance according to the actual situation, which determines whether the waveform is abnormal based on the peak difference between two adjacent peaks.

[0117] Specifically, if the total number of samples corresponding to the corrected waveform of the left edge point group of the peak is not within the range formed by the lower limit and the upper limit of the preset corrected waveform period sampling number, or if the number of samples of the trough is less than or equal to the preset corrected waveform half-cycle sampling number threshold, it can be considered that the corrected waveform corresponding to the left edge point group of the peak does not exist. Figure 6 The anomaly shown; however, if the difference between adjacent peaks corresponding to the waveform at the left edge of the peak is less than or equal to the preset peak difference threshold, it can be considered that the corrected waveform corresponding to the left edge of the peak does not exist. Figure 5 The abnormality shown can be used to determine whether the corrected waveform corresponding to the left edge point group of the peak is a leakage waveform, based on the slope value, preset slope threshold and preset slope judgment condition obtained above.

[0118] Optionally, whether there is an abnormal peak difference in the waveform corresponding to the left edge point group of the peak can be determined based on the difference between its adjacent peaks and a preset peak difference threshold. When the difference between its adjacent peaks is greater than the preset peak difference threshold, the abnormal correction wave signal waveform corresponding to the left edge point group of the peak can be considered as a leakage waveform with an abnormal peak difference.

[0119] For example Figure 5 As shown, the abnormal correction waveform exhibits an abnormal situation where the difference between adjacent peaks is too large. This can be determined based on the difference between adjacent peaks between two waveform peaks corresponding to the left edge point group and the total number of samples in the left edge point group. Meanwhile, due to... Figure 5 The abnormal correction wave signal waveform shown refers to the anomaly between two adjacent waveform peaks within a correction wave signal period. Therefore, the presence of such an anomaly is determined by the difference between adjacent peaks between the two waveform peaks corresponding to the left edge point group. Figure 5 When the anomaly shown is detected, it can be determined first by using the pre-defined lower limit of the number of samples in the corrected wave period, the upper limit of the number of samples in the corrected wave period, the threshold of the number of samples in the corrected wave half-cycle, and the total number of samples and the number of samples corresponding to the left edge point group of the peak, to determine whether the corrected wave waveform does not exist. Figure 6 The anomaly shown.

[0120] Specifically, if the total number of samples corresponding to the corrected waveform of the left edge point group of the peak is not within the range formed by the lower limit and the upper limit of the preset corrected waveform period sampling number, or if the number of samples of the trough is less than or equal to the preset corrected waveform half-cycle sampling number threshold, it can be considered that the corrected waveform corresponding to the left edge point group of the peak does not exist. Figure 6 The anomaly shown can be used to determine whether the corrected waveform corresponding to the left edge point group is a leakage current waveform based on the difference between adjacent peaks of the two peaks corresponding to the left edge point group and a preset peak difference threshold. Specifically, the two peaks corresponding to the left edge point group are the peaks within the left edge point group itself, and the peaks within the adjacent left edge point group; that is, the two peaks can be the peaks within the left edge point group and the peaks in the next left edge point group following the left edge point group; or they can be the peaks within the left edge point group and the peaks in the previous left edge point group preceding the left edge point group. In other words, if the difference between adjacent peaks is greater than the preset peak difference threshold, the corrected waveform corresponding to the left edge point group is considered to be a leakage current waveform. Figure 5 The waveform shown is abnormal in terms of peak difference.

[0121] For example Figure 6 As shown, the abnormal correction wave signal waveform represents the abnormal situation of the peak of a certain half-cycle. Based on the total number of samples and the number of samples corresponding to the left edge point group of the peak, as well as the pre-given lower limit, upper limit, and lower limit of the number of samples in the pre-defined correction wave period, it can be determined whether the correction wave waveform corresponding to the left edge point group of the peak exhibits the abnormality. Figure 6 The anomaly shown.

[0122] Specifically, the preset trough sampling threshold can be understood as a threshold set in advance based on the actual situation, indicating the number of sampling points required to indicate that a trough in a corrected waveform may be too long and there may be a problem of missing half-cycle peaks. Optionally, the preset trough sampling threshold can be the number of half-cycle samples of the corrected waveform.

[0123] Specifically, when such as Figure 6 The abnormal corrected wave signal waveform shown indicates that half a cycle of the corrected wave signal peak is missing within a cycle. In other words, the length of the corrected wave waveform corresponding to a group of points on the left edge of the peak will change from half a cycle to the entire corrected wave cycle. At this point, the range of sampling points within a corrected wave cycle can be limited by setting an upper limit and a lower limit for the number of samples in the corrected wave cycle. When the total number of samples corresponding to the group of points on the left edge of the peak falls within this range, it can be preliminarily considered that the corrected wave waveform corresponding to the group of points on the left edge of the peak has a missing half-cycle peak. To further confirm this anomaly, based on the following... Figure 6 The waveform example shown illustrates that when a missing half-cycle peak occurs, the trough length in the corrected waveform corresponding to the left edge point group of the peak will exceed the length of the corrected half-cycle. In this case, the number of trough samples corresponding to the left edge point group of the peak can be compared with the number of samples corresponding to the half-cycle of the corrected wave, or a preset threshold for the number of trough samples. If the number of trough samples is greater than the preset threshold, then the corrected waveform corresponding to the left edge point group of the peak is considered as follows: Figure 6 The waveform shown is an abnormal leakage current waveform with missing half-cycle peaks.

[0124] It is understandable that the above refers to, for example Figures 4-6 The determination of abnormal leakage waveforms can be performed in any order or simultaneously, and the embodiments of the present invention do not impose any restrictions on this.

[0125] Optionally, the leakage current detection result is determined based on the distribution of each leakage current waveform within the leakage current determination period, including at least one of the following:

[0126] When the number of consecutive occurrences of each leakage waveform within the leakage determination period exceeds the second preset number, the existence of leakage phenomenon is determined as a leakage detection result.

[0127] When the number of occurrences of each leakage waveform within the leakage judgment period exceeds the third preset number, the existence of leakage phenomenon will be determined as a leakage detection result.

[0128] In this embodiment, the second preset quantity and the third preset quantity can be understood as being preset according to the actual situation, and are used to indicate the distribution of each leakage waveform within the leakage determination period, indicating the threshold number of leakage phenomena within the leakage determination period.

[0129] Specifically, to avoid inaccurate leakage detection results caused by assuming a single leakage waveform indicates a leakage problem in the DC-AC inverter, this embodiment of the invention considers the distribution of multiple leakage waveforms within the leakage determination period to comprehensively determine whether a leakage problem has occurred. In some examples, the number of consecutive leakage waveforms within the leakage determination period can be given priority. That is, when the number of consecutive leakage waveforms exceeds a second preset number, it can be considered that the AC voltage waveforms continuously output by the DC-AC inverter over a period of time all have problems, and the presence of leakage can be determined as a leakage detection result. In some examples, the total number of leakage waveforms within the leakage determination period can be considered, without limiting whether these leakage waveforms appear consecutively. That is, when the number of leakage waveforms within the leakage determination period exceeds a third preset number, it can be considered that the DC-AC inverter has experienced too many abnormal AC voltage waveforms over a period of time, possibly reflecting a leakage problem, and the presence of leakage can be determined as a leakage detection result.

[0130] In some examples, taking the leakage current detection method of half-cycle peak missing anomaly as an example, Figure 8 This is a flowchart illustrating a leakage current detection method provided in an embodiment of the present invention, which can be implemented through the following steps:

[0131] S301, Obtain the signal to be processed within the leakage current determination period.

[0132] S302. Determine the peak points of the waveform within the leakage current determination period based on the signal to be processed, as well as the left edge points of the peaks corresponding to each peak point.

[0133] Optionally, determining the peak points of the waveform within the leakage current determination period, and the corresponding left edge points of each peak point, based on the signal to be processed, can be achieved in the following way:

[0134] The analog-to-digital conversion value of each sampling point within the leakage current determination period is determined based on the signal to be processed, and the analog-to-digital conversion difference between each adjacent sampling point is determined; the analog-to-digital conversion difference is the difference between the analog-to-digital conversion value of the sampling point with the later sampling time and the analog-to-digital conversion value of the sampling point with the earlier sampling time among adjacent sampling points;

[0135] When the sign of two adjacent analog-to-digital conversion differences changes from positive to negative, and the sign of the first preset number of analog-to-digital conversion differences after the two adjacent analog-to-digital conversion differences is negative, the overlapping sampling points among the sampling points corresponding to the two adjacent analog-to-digital conversion differences are determined as candidate waveform peak points.

[0136] If the peak value of the candidate waveform peak point is greater than the preset effective peak value threshold, then the candidate waveform peak point is determined as the waveform peak point within the leakage current determination period;

[0137] For each waveform peak point, determine the first target analog-to-digital conversion difference corresponding to the waveform peak point, and determine the sampling point with the later sampling time among the sampling points corresponding to the first target analog-to-digital conversion difference as the left edge point of the peak corresponding to the waveform peak point;

[0138] The first target analog-to-digital conversion difference is the first analog-to-digital conversion difference that is greater than the preset difference threshold, located before the peak point of the waveform.

[0139] S303. Determine each pair of adjacent left edge points of a peak as a group of left edge points of a peak, and count the total number of samples and the number of trough samples corresponding to each group of left edge points of a peak.

[0140] S304. Based on the total number of samples, the number of samples in each trough, the lower limit of the preset correction wave period sampling number, the upper limit of the preset correction wave period sampling number, and the preset trough sampling number threshold, determine the leakage waveform from the correction wave waveform corresponding to the left edge point group of each peak.

[0141] Optionally, the leakage current waveform can be determined from the corrected waveform corresponding to each peak's left edge point group based on the total number of samples, the number of samples at each trough, the lower limit of the preset corrected waveform period sampling number, the upper limit of the preset corrected waveform period sampling number, and the preset trough sampling number threshold. This can be achieved in the following way:

[0142] The corrected waveform corresponding to the left edge point group of the peak where the total number of samples is within the range formed by the lower limit of the preset corrected waveform period sampling number and the upper limit of the preset corrected waveform period sampling number, and the number of trough samples is greater than the preset trough sampling number threshold, is determined as the leakage waveform.

[0143] S305. Determine the leakage detection result based on the distribution of each leakage waveform within the leakage judgment period.

[0144] Optionally, the leakage current detection result can be determined based on the distribution of each leakage current waveform within the leakage current determination period, and can be determined by at least one of the following methods:

[0145] When the number of consecutive occurrences of each leakage waveform within the leakage judgment period exceeds the second preset number, the existence of leakage phenomenon will be determined as a leakage detection result.

[0146] When the number of occurrences of each leakage waveform within the leakage judgment period exceeds the third preset number, the existence of leakage phenomenon will be determined as a leakage detection result.

[0147] Optionally, the signal to be processed is the AC voltage output by the inverter, which is rectified and converted to obtain a correction wave signal; the leakage current determination period includes multiple correction wave periods.

[0148] Optionally, the signal to be processed is constructed from multiple sampling points obtained by sampling at fixed sampling intervals.

[0149] In some examples, taking the leakage current detection method that detects abnormally large differences between adjacent peaks as an example, Figure 9 This is a flowchart illustrating a leakage current detection method provided in an embodiment of the present invention, which can be implemented through the following steps:

[0150] S401, Obtain the signal to be processed within the leakage current determination period.

[0151] S402. Determine the peak points of the waveform within the leakage current determination period based on the signal to be processed, as well as the left edge points of the peaks corresponding to each peak point.

[0152] Optionally, determining the peak points of the waveform within the leakage current determination period, and the corresponding left edge points of each peak point, based on the signal to be processed, can be achieved in the following way:

[0153] The analog-to-digital conversion value of each sampling point within the leakage current determination period is determined based on the signal to be processed, and the analog-to-digital conversion difference between each adjacent sampling point is determined; the analog-to-digital conversion difference is the difference between the analog-to-digital conversion value of the sampling point with the later sampling time and the analog-to-digital conversion value of the sampling point with the earlier sampling time among adjacent sampling points;

[0154] When the sign of two adjacent analog-to-digital conversion differences changes from positive to negative, and the sign of the first preset number of analog-to-digital conversion differences after the two adjacent analog-to-digital conversion differences is negative, the overlapping sampling points among the sampling points corresponding to the two adjacent analog-to-digital conversion differences are determined as candidate waveform peak points.

[0155] If the peak value of the candidate waveform peak point is greater than the preset effective peak value threshold, then the candidate waveform peak point is determined as the waveform peak point within the leakage current determination period;

[0156] For each waveform peak point, determine the first target analog-to-digital conversion difference corresponding to the waveform peak point, and determine the sampling point with the later sampling time among the sampling points corresponding to the first target analog-to-digital conversion difference as the left edge point of the peak corresponding to the waveform peak point;

[0157] The first target analog-to-digital conversion difference is the first analog-to-digital conversion difference that is greater than the preset difference threshold, located before the peak point of the waveform.

[0158] S403. Determine each pair of adjacent left-side edge points of a peak as a group of left-side edge points, and determine the adjacent peak difference between the two waveform peak points corresponding to the group of left-side edge points. Among them, the two waveform peak points corresponding to the group of left-side edge points are the waveform peak points within the group of left-side edge points, and the waveform peak points within the group of left-side edge points adjacent to the group of left-side edge points.

[0159] S404. Based on the difference between each adjacent peak and the preset peak difference threshold, determine the leakage waveform from the corrected waveform corresponding to the left edge point group of each peak.

[0160] Optionally, the leakage current waveform can be determined from the corrected waveform corresponding to the left edge point group of each peak based on the difference between each adjacent peak and a preset peak difference threshold. This can be achieved in the following way:

[0161] The corrected waveform corresponding to the left edge point group of the peak where the difference between adjacent peaks is greater than the preset peak difference threshold is determined as the leakage current waveform.

[0162] S405. Determine the leakage detection result based on the distribution of each leakage waveform within the leakage judgment period.

[0163] Optionally, the leakage current detection result can be determined based on the distribution of each leakage current waveform within the leakage current determination period, and can be determined by at least one of the following methods:

[0164] When the number of consecutive occurrences of each leakage waveform within the leakage judgment period exceeds the second preset number, the existence of leakage phenomenon will be determined as a leakage detection result.

[0165] When the number of occurrences of each leakage waveform within the leakage judgment period exceeds the third preset number, the existence of leakage phenomenon will be determined as a leakage detection result.

[0166] Optionally, the signal to be processed is the AC voltage output by the inverter, which is rectified and converted to obtain a correction wave signal; the leakage current determination period includes multiple correction wave periods.

[0167] Optionally, the signal to be processed is constructed from multiple sampling points obtained by sampling at fixed sampling intervals.

[0168] In some examples, taking leakage current detection methods with abnormal slopes as an example, Figure 10 This is a flowchart illustrating a leakage current detection method provided in an embodiment of the present invention, which can be implemented through the following steps:

[0169] S501, Obtain the signal to be processed within the leakage current determination period.

[0170] S502. Determine the peak points of the waveform within the leakage current determination period based on the signal to be processed, as well as the left and right edge points of the peaks corresponding to each peak point.

[0171] Optionally, the peak points of the waveform within the leakage current determination period, as well as the left and right edge points corresponding to each peak point, can be determined based on the signal to be processed in the following way:

[0172] The analog-to-digital conversion value of each sampling point within the leakage current determination period is determined based on the signal to be processed, and the analog-to-digital conversion difference between each adjacent sampling point is determined; the analog-to-digital conversion difference is the difference between the analog-to-digital conversion value of the sampling point with the later sampling time and the analog-to-digital conversion value of the sampling point with the earlier sampling time among adjacent sampling points;

[0173] When the sign of two adjacent analog-to-digital conversion differences changes from positive to negative, and the sign of the first preset number of analog-to-digital conversion differences after the two adjacent analog-to-digital conversion differences is negative, the overlapping sampling points among the sampling points corresponding to the two adjacent analog-to-digital conversion differences are determined as candidate waveform peak points.

[0174] If the peak value of the candidate waveform peak point is greater than the preset effective peak value threshold, then the candidate waveform peak point is determined as the waveform peak point within the leakage current determination period;

[0175] For each waveform peak point, a first target analog-to-digital conversion difference corresponding to the waveform peak point is determined, and the sampling point with the later sampling time among the sampling points corresponding to the first target analog-to-digital conversion difference is determined as the left edge point of the peak corresponding to the waveform peak point; the first target analog-to-digital conversion difference is the first analog-to-digital conversion difference that is greater than the preset difference threshold located before the waveform peak point;

[0176] For each waveform peak point, determine the second target analog-to-digital conversion difference corresponding to the waveform peak point, and determine the sampling point with the earlier sampling time among the sampling points corresponding to the second target analog-to-digital conversion difference as the right edge point of the peak corresponding to the waveform peak point; the second target analog-to-digital conversion difference is the first analog-to-digital conversion difference located after the waveform peak point whose absolute value is greater than the preset difference threshold.

[0177] S503. Determine each pair of adjacent left-side peak points as a group of left-side peak points. For each group of left-side peak points, determine the slope value corresponding to the group of left-side peak points based on the relative positional relationship between the waveform peak points and the corresponding left-side and right-side peak points within the group of left-side peak points, as well as the analog-to-digital conversion value of each sampling point in the group of left-side peak points.

[0178] Optionally, the slope value corresponding to the left edge point group can be determined based on the relative positional relationship between the waveform peak point and the corresponding left and right edge points within the left edge point group, as well as the analog-to-digital conversion value of each sampling point in the left edge point group. This can be achieved in the following way:

[0179] When the distance between the peak point of the waveform and the corresponding left edge point within the left edge point group is less than the distance between the peak point and the corresponding right edge point, the slope value corresponding to the left edge point group is determined based on the analog-to-digital conversion values ​​of each sampling point between the peak point and the right edge point; where the slope value corresponding to the left edge point group is negative.

[0180] When the distance between the peak point of the waveform and the corresponding left edge point in the left edge point group is greater than the distance between the peak point and the corresponding right edge point, the slope value corresponding to the left edge point group is determined based on the analog-to-digital conversion value of each sampling point between the left edge point and the peak point of the waveform; wherein, the slope value corresponding to the left edge point group is a positive value.

[0181] S504. Based on each slope value and the preset slope threshold, determine the leakage current waveform from the corrected waveform corresponding to the left edge point group of each peak.

[0182] Optionally, based on each slope value and a preset slope threshold, the leakage current waveform can be determined from the corrected waveform corresponding to the left edge point group of each peak. This can be achieved in the following way:

[0183] The corrected waveform corresponding to the left edge point group of the peak whose slope value meets the preset slope judgment condition is determined as the leakage current waveform.

[0184] Optionally, when the slope value is negative, the preset slope determination condition is that the slope value is less than a preset slope threshold;

[0185] When the slope value is positive, the preset slope determination condition is that the slope value is greater than the preset slope threshold;

[0186] The preset slope threshold takes different values ​​depending on the sign value corresponding to the slope value.

[0187] S505. Determine the leakage detection result based on the distribution of each leakage waveform within the leakage judgment period.

[0188] Optionally, the leakage current detection result can be determined based on the distribution of each leakage current waveform within the leakage current determination period, and can be determined by at least one of the following methods:

[0189] When the number of consecutive occurrences of each leakage waveform within the leakage judgment period exceeds the second preset number, the existence of leakage phenomenon will be determined as a leakage detection result.

[0190] When the number of occurrences of each leakage waveform within the leakage judgment period exceeds the third preset number, the existence of leakage phenomenon will be determined as a leakage detection result.

[0191] Optionally, the signal to be processed is the AC voltage output by the inverter, which is rectified and converted to obtain a correction wave signal; the leakage current determination period includes multiple correction wave periods.

[0192] Optionally, the signal to be processed is constructed from multiple sampling points obtained by sampling at fixed sampling intervals.

[0193] In some examples, taking the leakage current detection method that first checks for half-cycle peak missing anomalies, then for excessively large differences between adjacent peaks, and finally for slope anomalies as an example, the entire leakage current detection process can be divided into two parts: a detection stage and a judgment stage. Figure 11 This is a flowchart illustrating a leakage current detection method provided in an embodiment of the present invention, which can be implemented through the following steps:

[0194] S601, Obtain the signal to be processed within the leakage current determination period.

[0195] S602. Determine at least one of the following based on the signal to be processed: the peak point of the waveform within the leakage current determination period, the left edge point of the peak corresponding to each peak point, the difference between adjacent peaks, the total number of samples between adjacent left edge points, and the number of samples between adjacent left edge points.

[0196] S603. For a group of left-side edge points determined based on the left-side edge points of adjacent peaks within the leakage current determination period, determine whether the total number of samples N corresponding to the group of left-side edge points is within the interval [A1, A2] and whether the number of samples H of the valleys corresponding to the group of left-side edge points is greater than the threshold B; if yes, then execute S607; if no, then execute S604.

[0197] Wherein, A1 can be understood as the lower limit of the number of preset corrected wave period samples defined above; A2 can be understood as the upper limit of the number of preset corrected wave period samples defined above; threshold B can be understood as the threshold of the number of preset valley samples defined above.

[0198] S604. Determine whether the difference M between adjacent peaks is greater than the threshold C; if yes, proceed to S607; if no, proceed to S605.

[0199] Here, threshold C can be understood as the preset peak difference threshold defined above.

[0200] Understandably, the threshold C needs to be selected based on the actual situation, and its setting should not be too small to prevent false triggering of leakage current detection. For example, assuming that the value of the peak point of the sampled waveform is 3000, the selected threshold C can be 1000.

[0201] S605. Based on the relative positional relationship between the peak point and the left and right edge points of the waveform within the left edge point group, and the analog-to-digital conversion value of each sampling point in the left edge point group, determine the slope value corresponding to the left edge point group.

[0202] S606. Determine if the slope value is greater than the threshold D; if yes, execute S607; if no, return to execute S603.

[0203] Here, threshold D can be understood as the preset slope threshold defined above. For example, threshold D can be set as the minimum slope within the leakage current determination period when the maximum leakage resistance is shorted.

[0204] S607, A leakage waveform has been detected.

[0205] S608. Determine whether E leakage waveforms have been detected consecutively, or whether the number of occurrences of leakage waveforms is greater than F; if yes, execute S609; if no, return to execute S603.

[0206] Where E can be understood as the second preset quantity defined above; F can be understood as the third preset quantity defined above.

[0207] It is understandable that when S606 and S608 return to execute S603, they will select another group of left-side peak points determined based on the left-side peak points of adjacent peaks within the leakage current determination cycle to determine the leakage current waveform. The other group of left-side peak points selected should be the group of left-side peak points that has not been used to determine the leakage current waveform before.

[0208] S609. The leakage current detection result is confirmed to indicate the presence of leakage current.

[0209] Optionally, when a leakage current is detected in the DC-AC inverter, leakage protection can be triggered to shut down the inverter's output; conversely, when the leakage current detection result indicates that there is no leakage current, the inverter's normal output can be maintained.

[0210] In this embodiment of the invention, by combining three abnormal waveform judgment methods—half-cycle peak missing, adjacent peak difference, and slope—leakage detection is covered for most different load conditions of DC-AC inverters, thereby improving the accuracy of leakage detection.

[0211] In one exemplary implementation Figure 12 This is a schematic diagram of a leakage current detection device provided in an embodiment of the present invention, as shown below. Figure 12 As shown, the leakage current detection device includes a processor 71 and a memory 72 connected to the processor 71. The memory 72 stores signal acquisition program code, key point determination program code, sample number determination program code, peak difference determination program code, slope value determination program code, leakage current waveform determination program code, and detection result determination program code.

[0212] The processor 71 is configured to execute signal acquisition program code to acquire signals to be processed within the leakage current determination period.

[0213] The processor 71 is also configured to execute key point determination code to determine the waveform peak points within the leakage current determination period, and the corresponding left edge points of each waveform peak point, based on the signal to be processed. Alternatively, it may determine the waveform peak points within the leakage current determination period, and the corresponding left and right edge points of each waveform peak point, based on the signal to be processed.

[0214] The processor 71 is also configured to execute sample number determination code to determine every two adjacent left edge points of the peak as a group of left edge points of the peak, and to count the total number of samples and the number of trough samples corresponding to each group of left edge points of the peak.

[0215] The processor 71 is also configured to execute peak difference determination code to define every two adjacent left-side edge points of a peak as a group of left-side edge points, and to determine the adjacent peak difference between two waveform peak points corresponding to the group of left-side edge points. The two waveform peak points corresponding to the group of left-side edge points are the waveform peak points within the group of left-side edge points, and the waveform peak points within the group of left-side edge points adjacent to the group of left-side edge points.

[0216] The processor 71 is also configured to execute slope value determination code to determine every two adjacent left-side peak points as a group of left-side peak points, and for each group of left-side peak points, determine the slope value corresponding to the group of left-side peak points based on the relative positional relationship between the waveform peak points in the group of left-side peak points and the corresponding left-side and right-side peak points, as well as the analog-to-digital conversion value of each sampling point in the group of left-side peak points.

[0217] The processor 71 is also configured to execute leakage current waveform determination program code to determine the leakage current waveform from the corrected waveform corresponding to each peak left edge point group based on the total number of samples, the number of samples for each trough, a preset lower limit for the number of samples for the corrected waveform period, a preset upper limit for the number of samples for the corrected waveform period, and a preset trough sampling threshold. Alternatively, it can be used to determine the leakage current waveform from the corrected waveform corresponding to each peak left edge point group based on the difference between each adjacent peak and a preset peak difference threshold. Alternatively, it can be used to determine the leakage current waveform from the corrected waveform corresponding to each peak left edge point group based on each slope value and a preset slope threshold.

[0218] The processor 71 is also configured to execute detection result determination code to determine the leakage detection result based on the distribution of each leakage waveform within the leakage determination period.

[0219] In one exemplary implementation Figure 13 This is a schematic diagram of a leakage current detection device provided in an embodiment of the present invention. The leakage current detection device 80 can represent various forms of digital computers, such as laptop computers, desktop computers, workbenches, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The leakage current detection device 80 can also represent various forms of mobile devices, such as personal digital assistants, cellular phones, smartphones, wearable devices (such as helmets, glasses, watches, etc.), and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely illustrative and are not intended to limit the implementation of the invention described and / or claimed herein.

[0220] like Figure 13As shown, the leakage current detection device 80 includes at least one processor 81 and a memory, such as a read-only memory (ROM) 82 or a random access memory (RAM) 83, communicatively connected to the at least one processor 81. The memory stores computer programs executable by the at least one processor. The processor 81 can perform various appropriate actions and processes based on the computer program stored in the ROM 82 or loaded from storage unit 88 into the RAM 83. The RAM 83 can also store various programs and data required for the operation of the leakage current detection device 80. The processor 81, ROM 82, and RAM 83 are interconnected via a bus 84. An input / output (I / O) interface 85 is also connected to the bus 84.

[0221] Multiple components in the leakage current detection device 80 are connected to the I / O interface 85, including: an input unit 86, such as a keyboard, mouse, etc.; an output unit 87, such as various types of displays, speakers, etc.; a storage unit 88, such as a disk, optical disk, etc.; and a communication unit 89, such as a network card, modem, wireless transceiver, etc. The communication unit 89 allows the leakage current detection device 80 to exchange information / data with other devices through computer networks such as the Internet and / or various telecommunications networks.

[0222] Processor 81 can be a variety of general-purpose and / or special-purpose processing components with processing and computing capabilities. Some examples of processor 81 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various special-purpose artificial intelligence (AI) computing chips, various processors running machine learning model algorithms, a digital signal processor (DSP), and any suitable processor, controller, microcontroller, etc. Processor 81 performs the various methods and processes described above, such as leakage current detection methods.

[0223] In some embodiments, the leakage current detection method may be implemented as a computer program tangibly contained in a computer-readable storage medium, such as storage unit 88. In some embodiments, part or all of the computer program may be loaded and / or installed on the leakage current detection device 80 via ROM 82 and / or communication unit 89. When the computer program is loaded into RAM 83 and executed by processor 81, one or more steps of the leakage current detection method described above may be performed. Alternatively, in other embodiments, processor 81 may be configured to perform the leakage current detection method by any other suitable means (e.g., by means of firmware).

[0224] Optionally, embodiments of the present invention also provide a computer program product, including a computer program that, when executed by a processor, implements the leakage current detection method as provided in any embodiment of the present invention.

[0225] Various embodiments of the systems and techniques described above herein can be implemented in digital electronic circuit systems, integrated circuit systems, field-programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), application-specific standard products (ASSPs), systems-on-a-chip (SoCs), payload-programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various embodiments may include implementations in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which may be a dedicated or general-purpose programmable processor, capable of receiving data and instructions from a storage system, at least one input device, and at least one output device, and transmitting data and instructions to the storage system, the at least one input device, and the at least one output device.

[0226] Computer programs used to implement the methods of the present invention may be written in any combination of one or more programming languages. These computer programs may be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device, such that when executed by the processor, the computer programs cause the functions / operations specified in the flowcharts and / or block diagrams to be performed. The computer programs may be executed entirely on a machine, partially on a machine, or as a standalone software package, partially on a machine and partially on a remote machine, or entirely on a remote machine or server.

[0227] In the context of this invention, a computer-readable storage medium can be a tangible medium that may contain or store a computer program for use by or in conjunction with an instruction execution system, apparatus, or device. A computer-readable storage medium may include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination thereof. Alternatively, a computer-readable storage medium may be a machine-readable signal medium. More specific examples of machine-readable storage media include electrical connections based on one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fibers, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof.

[0228] To provide user interaction, the systems and techniques described herein can be implemented on a leakage current detection device, which includes: a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to the user; and a keyboard and pointing device (e.g., a mouse or trackball) through which the user provides input to the leakage current detection device. Other types of devices can also be used to provide user interaction; for example, the feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user can be received in any form (including sound input, voice input, or tactile input).

[0229] The systems and technologies described herein can be implemented in computing systems that include backend components (e.g., as data servers), or middleware components (e.g., application servers), or frontend components (e.g., user computers with graphical user interfaces or web browsers through which users can interact with implementations of the systems and technologies described herein), or any combination of such backend, middleware, or frontend components. The components of the system can be interconnected via digital data communication of any form or medium (e.g., communication networks). Examples of communication networks include local area networks (LANs), wide area networks (WANs), blockchain networks, and the Internet.

[0230] A computing system can include clients and servers. Clients and servers are generally located far apart and typically interact through communication networks. The client-server relationship is created by computer programs running on the respective computers and having a client-server relationship with each other. The server can be a cloud server, also known as a cloud computing server or cloud host, which is a hosting product within the cloud computing service system to address the shortcomings of traditional physical hosts and VPS services, such as high management difficulty and weak business scalability.

[0231] It should be understood that the various forms of processes shown above can be used, with steps reordered, added, or deleted. For example, the steps described in this invention can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this invention can be achieved, and this is not limited herein.

[0232] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A leakage current detection method, characterized in that, include: Acquire the signals to be processed within the leakage current determination period; Based on the signal to be processed, determine the peak points of the waveform within the leakage current determination period, as well as the left and right edge points of the peaks corresponding to each peak point; Each pair of adjacent left edge points of the peak is defined as a group of left edge points of the peak. The peak point of the waveform within each group of left edge points of the peak is determined, as well as the relative positional relationship between the peak point of the waveform and the corresponding left edge point and right edge point of the peak. Based on the relative positional relationship between the waveform peak point and the corresponding left and right edge points in each left edge point group, and the analog-to-digital conversion value of each sampling point in the left edge point group, the slope value corresponding to the left edge point group is determined. Based on the slope values ​​and the preset slope threshold, the leakage current waveform is determined from the corrected waveform corresponding to the left edge point group of each peak; The leakage detection result is determined based on the distribution of each leakage waveform within the leakage determination period.

2. The leakage current detection method according to claim 1, characterized in that, The step of determining the leakage current waveform from the corrected waveform corresponding to each of the left edge point groups of the peaks based on each slope value and a preset slope threshold includes: The corrected waveform corresponding to the left edge point group of the peak whose slope value and the preset slope threshold satisfy the preset slope determination condition is determined as the leakage current waveform.

3. The leakage current detection method according to claim 1, characterized in that, The step of determining the waveform peak points within the leakage current determination period based on the signal to be processed, and the left and right edge points corresponding to each waveform peak point, includes: The analog-to-digital conversion value of each sampling point within the leakage current determination period is determined based on the signal to be processed, and the analog-to-digital conversion difference between adjacent sampling points is determined; the analog-to-digital conversion difference is the difference between the analog-to-digital conversion value of the sampling point with a later sampling time and the analog-to-digital conversion value of the sampling point with a earlier sampling time among the adjacent sampling points; When the sign of two adjacent analog-to-digital conversion differences changes from positive to negative, and the sign of the first preset number of analog-to-digital conversion differences after the two adjacent analog-to-digital conversion differences is negative, the overlapping sampling points among the sampling points corresponding to the two adjacent analog-to-digital conversion differences are determined as candidate waveform peak points. If the peak value of the candidate waveform peak point is greater than the preset effective peak value threshold, then the candidate waveform peak point is determined as the waveform peak point within the leakage current determination period; For each waveform peak point, a first target analog-to-digital conversion difference corresponding to the waveform peak point is determined, and the sampling point with the later sampling time among the sampling points corresponding to the first target analog-to-digital conversion difference is determined as the left edge point of the peak corresponding to the waveform peak point; the first target analog-to-digital conversion difference is the first analog-to-digital conversion difference that is greater than a preset difference threshold located before the waveform peak point; For each waveform peak point, a second target analog-to-digital conversion difference corresponding to the waveform peak point is determined, and the sampling point with the earlier sampling time among the sampling points corresponding to the second target analog-to-digital conversion difference is determined as the right edge point of the peak corresponding to the waveform peak point; the second target analog-to-digital conversion difference is the first analog-to-digital conversion difference located after the waveform peak point whose absolute value is greater than a preset difference threshold.

4. The leakage current detection method according to claim 1, characterized in that, The step of determining the slope value corresponding to the left edge point group based on the relative positional relationship between the waveform peak point and the corresponding left and right edge points within each left edge point group, and the analog-to-digital conversion value of each sampling point in the left edge point group, includes: When the distance between the waveform peak point and the corresponding left edge point in the left edge point group is less than the distance between the peak point and the corresponding right edge point, the slope value corresponding to the left edge point group is determined based on the analog-to-digital conversion value of each sampling point between the waveform peak point and the right edge point; wherein, the slope value corresponding to the left edge point group is negative. When the distance between the peak point of the waveform and the corresponding left edge point in the left edge point group is greater than the distance between the peak point and the corresponding right edge point, the slope value corresponding to the left edge point group is determined based on the analog-to-digital conversion value of each sampling point between the left edge point and the peak point of the waveform; wherein, the slope value corresponding to the left edge point group is a positive value.

5. The leakage current detection method according to claim 2, characterized in that, When the slope value is negative, the preset slope determination condition is that the slope value is less than the preset slope threshold. When the slope value is positive, the preset slope determination condition is that the slope value is greater than the preset slope threshold. The preset slope threshold takes different values ​​when the sign value corresponding to the slope value is different.

6. The leakage current detection method according to any one of claims 1-5, characterized in that, The determination of the leakage current detection result based on the distribution of each leakage current waveform within the leakage current determination period includes at least one of the following: When the number of consecutive occurrences of each of the aforementioned leakage waveforms within the leakage determination period exceeds the second preset number, the existence of leakage phenomenon will be determined as a leakage detection result. When the number of occurrences of each of the aforementioned leakage waveforms within the leakage determination period exceeds a third preset number, the existence of leakage phenomenon is determined as a leakage detection result.

7. The leakage current detection method according to any one of claims 1-5, characterized in that, The signal to be processed is the AC voltage output by the inverter, which is a corrected wave signal obtained after rectification and voltage conversion; the leakage current determination period includes multiple corrected wave periods.

8. The leakage current detection method according to any one of claims 1-5, characterized in that, The signal to be processed is constructed from multiple sampling points obtained by sampling at a fixed sampling interval.

9. A leakage current detection device, characterized in that, It includes a processor and a memory connected to the processor, wherein the memory stores signal acquisition program code, key point determination program code, position relationship determination program code, slope value determination program code, leakage waveform determination program code, and detection result determination program code; The processor is configured to execute the signal acquisition program code to acquire the signal to be processed within the leakage current determination period; The processor is further configured to execute the key point determination program code to determine the waveform peak point within the leakage current determination period based on the signal to be processed, as well as the left and right edge points of each waveform peak point. The processor is further configured to execute the positional relationship determination program code to determine every two adjacent left edge points of the peak as a group of left edge points of the peak, determine the waveform peak points within each group of left edge points of the peak, and the relative positional relationship between the waveform peak points and the corresponding left and right edge points of the peak. The processor is further configured to execute the slope value determination program code to determine the slope value corresponding to the left edge point group based on the relative positional relationship between the waveform peak point and the corresponding left edge point and right edge point in each left edge point group, and the analog-to-digital conversion value of each sampling point in the left edge point group. The processor is further configured to execute the leakage waveform determination program code to determine the leakage waveform from the corrected waveform corresponding to each of the peak left edge point groups based on each of the slope values ​​and a preset slope threshold. The processor is also configured to execute the detection result determination program code to determine the leakage detection result based on the distribution of each leakage waveform within the leakage determination period.

10. A leakage current detection device, characterized in that, include: At least one processor; and a memory communicatively connected to the at least one processor; The memory stores a computer program that can be executed by the at least one processor, which is then executed by the at least one processor to enable the at least one processor to perform the leakage current detection method according to any one of claims 1-8.

11. A storage medium containing computer-executable instructions, characterized in that, The computer-executable instructions, when executed by a computer processor, are used to perform the leakage current detection method as described in any one of claims 1-8.

12. A computer program product, characterized in that, It includes a computer program that, when executed by a processor, implements the leakage current detection method as described in any one of claims 1-8.

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