SoC-based series ac arc fault detection method, positioning method and device

Abstract

The application discloses a series AC arc fault detection method, positioning method and device based on SoC. Firstly, the voltage signal and the current signal in the low-voltage power distribution system are acquired through an arc fault detection SoC chip, then the wavelet decomposed voltage signal and current signal are compared with the set threshold value, whether the arc fault occurs is determined according to the current domain comparison result, and the fault branch is discriminated according to the voltage domain comparison result. When the arc fault is determined to occur, the voltage signal and the current signal of the source end and the load end of the power distribution line are collected and recorded through the SoC chip, and the FFT transformation is performed, then the positioning equation of the series arc fault position and the voltage signal and the current signal is substituted, the fault interval is quickly determined by successive approximation, and finally the fault point is determined according to the set searching fault point accuracy. The application has the characteristics of low cost and high integration, and can be used for realizing the automation of complex low-voltage power distribution system.

Description

Technical Field

[0001] This application relates to the field of terminal technology, and in particular to a method, method and device for detecting and locating series AC arc faults based on SoC. Background Technology

[0002] Traditional circuit breakers cannot effectively and promptly identify series fault arcs. If arc faults in power systems are not detected, located, and isolated in a timely manner, they can cause significant damage to equipment, and even lead to electrical fires and personal injury. Currently, there is a wealth of research on arc fault detection, with most studies focusing on detection algorithms. These systems utilize existing arc fault signal front-end acquisition circuits and board-level processors to perform calculations and data processing, resulting in high costs and poor portability for the entire arc fault detection system. Furthermore, traditional methods for fault location based on physical phenomena such as ultrasound and electromagnetic radiation are limited to fixed electrical installations and are unsuitable for low-voltage power distribution systems. Traveling wave methods suffer from transmission distortion and require sophisticated equipment, further increasing the cost of arc fault location systems. Summary of the Invention

[0003] In view of this, embodiments of this application provide a series AC arc fault detection method, location method and device based on SoC, which can detect series AC arc faults in low-voltage power distribution systems in real time and determine the fault branches, and locate the fault point in a timely manner. It has the characteristics of low cost and high integration, and can be used to realize the automation of complex low-voltage power distribution systems.

[0004] According to a first aspect of the embodiments of this application, a series AC arc fault detection method based on SoC is provided, comprising:

[0005] The voltage and current signals of different branches in the low-voltage power distribution system are obtained through an arc fault detection SoC chip.

[0006] Wavelet decomposition is performed on the voltage and current signals of the different branches to obtain the high-frequency components of the voltage and current signals after wavelet decomposition.

[0007] The high-frequency components of the voltage signal and the high-frequency components of the current signal are compared with their respective set thresholds;

[0008] The comparison results in the current domain are used to determine whether an arc fault has occurred. At the same time, the comparison results in the voltage domain are used to determine the fault branch.

[0009] Further, the step of performing wavelet decomposition on the voltage and current signals of the different branches to obtain the high-frequency components of the voltage and current signals after wavelet decomposition includes:

[0010] Perform discrete wavelet transforms on the voltage and current signals of the different branches respectively;

[0011] The high-frequency components of the voltage signal and the high-frequency components of the current signal after the first layer of decomposition are used as the high-frequency components of the voltage signal and the high-frequency components of the current signal after wavelet decomposition.

[0012] Furthermore, the determination of whether an arc fault has occurred is based on the comparison results in the current domain, and the judgment of the fault branch is also made in conjunction with the comparison results in the voltage domain, including:

[0013] When the peak value of the high-frequency component of the current signal exceeds a set threshold, an arc fault is determined to have occurred.

[0014] When the peak value of the high-frequency component of the voltage signal also exceeds the set threshold, it is determined that the arc fault occurred outside the branch.

[0015] If only the high-frequency component of the current signal exceeds the set threshold, it is determined that the arc fault occurred in that branch.

[0016] According to a second aspect of the embodiments of this application, a method for locating a series AC arc fault is provided, comprising:

[0017] Perform the SoC-based series AC arc fault detection method described in the first aspect;

[0018] After the SoC-based series AC arc fault detection method is completed, the voltage and current signals at the source and load ends of the power distribution line are collected and recorded by the arc fault detection SoC chip, wherein the source end is the first fault distance in the power distribution line and the load end is the second fault distance in the power distribution line.

[0019] Perform FFT transformation on the voltage and current signals at the source and load ends respectively to obtain the frequency domain voltage and current signals at the source and load ends.

[0020] Substituting the first fault distance, the second fault distance, and the frequency domain voltage and current signals at the source and load ends into the location equation for the series arc fault location with respect to the voltage and current signals, the difference between the first and second fundamental frequency components of the fault current is obtained. The first fundamental frequency component difference of the fault current is obtained by substituting the first fault distance into the location equation for the series arc fault location with respect to the voltage and current signals, and the second fundamental frequency component difference of the fault current is obtained by substituting the second fault distance into the location equation for the series arc fault location with respect to the voltage and current signals.

[0021] The fault range is determined by successively approximating the difference between the first fundamental frequency component and the second fundamental frequency component of the fault current.

[0022] Within the defined fault range, the location of the arc fault point is determined based on the set accuracy of the fault point search.

[0023] Furthermore, the step of successively approximating the fault interval based on the difference between the first fundamental frequency component and the difference between the second fundamental frequency component of the fault current includes:

[0024] When the product of the difference between the first fundamental frequency component and the difference between the second fundamental frequency component of the fault current is less than zero, it is determined that the actual arc fault point is located between the first fault distance and the second fault distance.

[0025] Assume the arc fault point is half the distance between the first and second faults, and substitute it together with the frequency domain voltage and current signals of the source and load ends into the localization equation of the series arc fault location and the voltage and current signals to obtain the fundamental frequency component difference of the fault point.

[0026] If the product of the fundamental frequency component difference at the fault point and the second fundamental frequency component difference is less than zero, then the actual arc fault point is located between the assumed arc fault point and the second fault distance. Then, the value of the assumed fault point is assigned to the first fault distance, and the first fundamental frequency component difference is recalculated. If the product of the fundamental frequency component difference at the fault point and the first fundamental frequency component difference is less than zero, then the actual arc fault point is located between the first fault distance and the assumed arc fault point. Then, the value of the assumed arc fault point is assigned to the second fault distance, and the second fundamental frequency component difference is recalculated.

[0027] If the product of the difference between the first fundamental frequency component and the difference between the second fundamental frequency component remains less than zero, continue iterating and assume that the arc fault point is half of the first fault distance and the second fault distance.

[0028] Furthermore, determining the location of the arc fault point within the defined fault range according to a set fault point search accuracy includes:

[0029] When the difference between the first fault distance and the second fault distance is less than the set accuracy of the fault point search during the process of successively approximating the fault range, the actual arc fault point is obtained as half of the first fault distance and the second fault distance at this time.

[0030] According to a third aspect of the embodiments of this application, a series AC arc fault detection device based on a SoC is provided, comprising:

[0031] The signal acquisition unit is used to acquire voltage and current signals of different branches in the low-voltage power distribution system through the arc fault detection SoC chip;

[0032] The signal decomposition unit is used to perform wavelet decomposition on the voltage signals and current signals of the different branches respectively, to obtain the high-frequency components of the voltage signal and the high-frequency components of the current signal after wavelet decomposition.

[0033] The comparison unit is used to compare the high-frequency components of the voltage signal and the high-frequency components of the current signal with their respective preset thresholds;

[0034] The fault determination unit is used to determine whether an arc fault has occurred based on the comparison results in the current domain, and at the same time, to determine the fault branch by combining the comparison results in the voltage domain.

[0035] According to a fourth aspect of the embodiments of this application, a series AC arc fault location device is provided, comprising:

[0036] An arc fault detection unit is used to execute the SoC-based series AC arc fault detection method described in the first aspect;

[0037] The signal acquisition unit is used to acquire and record voltage and current signals at the source and load ends of the power distribution line through the arc fault detection SoC chip after the SoC-based series AC arc fault detection method is completed. The source end is the first fault distance in the power distribution line, and the load end is the second fault distance in the power distribution line.

[0038] The signal transformation unit is used to perform FFT transformation on the voltage signal and current signal at the source end and the load end respectively to obtain the frequency domain voltage signal and frequency domain current signal at the source end and the load end.

[0039] The difference calculation unit is used to substitute the first fault distance, the second fault distance, and the frequency domain voltage and current signals of the source and load ends into the positioning equation of the series arc fault location with the voltage and current signals to obtain the difference between the first fundamental frequency component and the second fundamental frequency component of the fault current; wherein, the difference between the first fundamental frequency component of the fault current is obtained by substituting the first fault distance into the positioning equation of the series arc fault location with the voltage and current signals, and the difference between the second fundamental frequency component of the fault current is obtained by substituting the second fault distance into the positioning equation of the series arc fault location with the voltage and current signals.

[0040] The successive approximation unit is used to successively approximate the fault range based on the difference between the first fundamental frequency component and the second fundamental frequency component of the fault current.

[0041] The fault point determination unit is used to determine the location of the arc fault point within a defined fault range, based on a set fault point search accuracy.

[0042] According to a fifth aspect of the embodiments of this application, an electronic device is provided, comprising:

[0043] One or more processors;

[0044] Memory, used to store one or more programs;

[0045] When the one or more programs are executed by the one or more processors, the one or more processors perform the method as described in the first aspect or the second aspect.

[0046] According to a sixth aspect of the embodiments of this application, a computer-readable storage medium is provided, having stored thereon computer instructions that, when executed by a processor, implement the steps of the method as described in the first or second aspect.

[0047] The technical solutions provided by the embodiments of this application may include the following beneficial effects:

[0048] As can be seen from the above embodiments, this application improves the integration and portability of the arc fault detection system by integrating the fault signal acquisition and fault signal determination units into the same SoC chip; at the same time, thanks to the proposed dual-channel arc fault detection method in voltage domain and current domain, this invention can determine the fault branch on the basis of realizing arc fault detection.

[0049] Because the fault location is based on the equivalent model of the series AC arc fault distribution line, it does not require expensive equipment and is not limited to fixed equipment location scenarios, which has the advantage of low cost; at the same time, the successive approximation fault location method can quickly determine the fault point.

[0050] This application enables the detection and location of series AC arc faults in complex low-voltage power distribution systems with multiple branches. It also features low system cost and high integration, making it suitable for automating complex low-voltage power distribution systems.

[0051] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

[0052] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0053] Figure 1 This is a flowchart of a series AC arc fault detection method based on SoC disclosed in an embodiment of the present invention;

[0054] Figure 2 This is a schematic diagram of a series AC arc fault detection circuit based on SoC disclosed in an embodiment of the present invention;

[0055] Figure 3 This is a flowchart of a series AC arc fault location method disclosed in an embodiment of the present invention;

[0056] Figure 4This is an equivalent model diagram of a series AC arc fault power distribution line disclosed in an embodiment of the present invention;

[0057] Figure 5 This is a schematic diagram of a SoC-based series AC arc fault detection device disclosed in an embodiment of the present invention;

[0058] Figure 6 This is a schematic diagram of a series AC arc fault location device based on SoC disclosed in an embodiment of the present invention;

[0059] Figure 7 This is a schematic diagram of an application scenario for series arc fault detection and location in a complex low-voltage power distribution system with multiple branches, as disclosed in an embodiment of the present invention. Detailed Implementation

[0060] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0061] The terminology used in this application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The singular forms “a,” “the,” and “the” used in this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any or all possible combinations of one or more of the associated listed items.

[0062] It should be understood that although the terms first, second, third, etc., may be used in this application to describe various information, such information should not be limited to these terms. These terms are only used to distinguish information of the same type from one another. For example, without departing from the scope of this application, first information may also be referred to as second information, and similarly, second information may also be referred to as first information. Depending on the context, the word "if" as used herein may be interpreted as "when," "when," or "in response to determination."

[0063] Figure 1 This is a flowchart illustrating a SoC-based series AC arc fault detection method according to an exemplary embodiment, such as... Figure 1 As shown, the method may include the following steps:

[0064] S101. Obtain voltage and current signals of different branches in the low-voltage power distribution system through the arc fault detection SoC chip.

[0065] In the method provided by the embodiments of the present invention, the voltage and current signals of different branches in the low-voltage power distribution system are acquired by using a device for acquiring voltage and current signals based on an arc fault detection SoC chip.

[0066] S102. Perform wavelet decomposition on the voltage and current signals of the different branches to obtain the high-frequency components of the voltage and current signals after wavelet decomposition.

[0067] In the method provided by the embodiments of the present invention, after obtaining the voltage and current signals of different branches in the low-voltage power distribution system, the voltage and current signals of different branches are subjected to discrete wavelet transform for multi-level decomposition, and then the high-frequency components of the voltage signal and the high-frequency components of the current signal after the first level of decomposition are used as the high-frequency components of the voltage signal and the high-frequency components of the current signal after wavelet decomposition.

[0068] S103. Compare the high-frequency components of the voltage signal and the high-frequency components of the current signal with their respective set thresholds.

[0069] S104. Determine whether an arc fault has occurred based on the comparison results in the current domain. At the same time, combine the comparison results in the voltage domain to judge the fault branch.

[0070] Specifically, in the method provided by the embodiments of the present invention, when the peak value of the high-frequency component of the current signal after wavelet decomposition exceeds a set threshold, an arc fault is determined to have occurred.

[0071] When the peak value of the high-frequency component of the voltage signal also exceeds the set threshold, it is determined that the arc fault occurred outside the branch.

[0072] When only the peak value of the high-frequency component of the current signal exceeds the set threshold, it is determined that the arc fault occurs in that branch.

[0073] In another embodiment of the present invention, a series AC arc fault detection circuit 230 based on a SoC is provided, such as... Figure 2 As shown, it may include:

[0074] An external arc fault signal processing circuit 210 and an arc fault detection SoC chip 220 are included. The external arc fault signal processing circuit 210 is connected to the live wire and neutral wire in the low-voltage power distribution system to generate a fault voltage signal V and a fault current signal ΔV. The arc fault detection SoC chip 220 is connected to the external arc fault signal processing circuit 210 to acquire and process the fault voltage signal V and the fault current signal ΔV.

[0075] The off-chip arc fault signal processing circuit 210 includes a voltage signal processing circuit 211 and a current signal processing circuit 212. In the current signal processing circuit 212, a current sensor is used to sense the current in the main circuit and reduce the current proportionally according to the turns ratio. A common-mode voltage generation circuit is used to provide the common-mode voltage required by the circuit. A first resistor R1 and a second resistor R2 are connected in series on the left and right ends of the common-mode voltage point, respectively, and finally convert the current signal into a differential voltage signal ΔV. In the voltage signal processing circuit 211, a third resistor R3 and a fourth resistor R4 are connected in series between the live wire and the neutral wire to obtain a proportionally scaled voltage signal V.

[0076] The arc fault detection SoC chip 220 includes a dual-channel voltage and current front-end acquisition circuit 221 and an arc fault detection algorithm 222. The dual-channel voltage and current front-end acquisition circuit 221 includes a current signal acquisition circuit channel and a voltage signal acquisition circuit channel. The analog circuit portion of each channel consists of a PGA and a SARADC. The PGA is used to amplify and filter small signals, and then the SARADC samples the amplified and filtered signals and converts them into digital signals. The SARADC controller controls the SARADC's sampling mode, gating channel, sampling rate, etc., and transmits and processes the sampled data. The arc fault detection algorithm 222 includes a wavelet transform module and a fault analysis module. The digital signal output by the SARADC is decomposed by the wavelet transform module to obtain the high-frequency components of the voltage signal and the high-frequency components of the current signal. The fault analysis module compares the high-frequency components of the voltage signal and the high-frequency components of the current signal with their respective set thresholds. An arc fault is determined to have occurred when the peak value of the high-frequency component of the current signal after wavelet decomposition exceeds a set threshold. When a series arc fault occurs outside the load, the peak values ​​of both the high-frequency components of the voltage and current signals exceed the set thresholds. When a series arc fault occurs inside the load, only the peak value of the high-frequency component of the current signal exceeds the set threshold. Therefore, based on anomalies in the voltage and current domains, the arc fault branch can be identified; that is, the branch where an arc fault occurs only generates a fault alarm signal in the current domain.

[0077] Based on the arc fault detection method described above, this embodiment of the invention also provides a series AC arc fault location method, see [link to relevant documentation]. Figure 3 Specifically, it includes:

[0078] S101-S104 are used for arc fault detection and arc fault branch determination. By acquiring voltage and current signals from different branches in the low-voltage power distribution system, wavelet decomposition is performed on each signal to obtain high-frequency components of the voltage and current signals. These high-frequency components are then compared to their respective set thresholds. If the peak value of the high-frequency component of the current signal exceeds the set threshold, an arc fault is determined to have occurred. If the peak value of the high-frequency component of the voltage signal also exceeds the set threshold, the arc fault is determined to have occurred outside that branch. If only the peak value of the high-frequency component of the current signal exceeds the set threshold, the arc fault is determined to have occurred within that branch.

[0079] It should be noted that after the arc fault detection is completed, the arc fault location method is implemented based on the equivalent model of the series AC arc fault distribution line.

[0080] Optionally, in another embodiment of the present invention, such as Figure 4 The figure shown is an equivalent model diagram of a series AC arc fault distribution line.

[0081] The power distribution lines adopt a T-type equivalent model. The impedance per unit length of the power distribution line is Z. s Z s = r + jωl, where r is the resistance per unit length of the distribution line, and l is the inductance per unit length of the distribution line. The admittance per unit length of the distribution line is Z. p Z p =g + jωc, where g is the conductance per unit length of the distribution line, and c is the capacitance per unit length of the distribution line. Assume the total length of the distribution line from the power source to the load is d meters, the fault location is x meters from the source, and the equivalent series impedance during a series arc fault is Z. arc V1 and I1 represent the source voltage and current values, respectively; V2 and I2 represent the load voltage and current values, respectively. 1a and I 2a These represent the current values ​​flowing into and out of the fault point, respectively. Based on Kirchhoff's voltage and current laws, the location equation for a series arc fault, relating the current and voltage signals, is established as follows:

[0082] I 1a =-Z p xV1+(1+Z s Z p x 2 )I1

[0083] I 2a =Z p (dx)V2+(1+Z s Z p (dx) 2 )I2

[0084] S105. After the SoC-based series AC arc fault detection method is completed, the arc fault detection SoC chip collects and records the voltage and current signals at the source and load ends of the power distribution line; wherein, the source end is the first fault distance in the power distribution line, and the load end is the second fault distance in the power distribution line.

[0085] The method provided in the embodiments of the present invention utilizes, for example... Figure 2 The SoC-based arc fault detection circuit shown collects voltage signal V1 and current signal I1 at the source end of the power distribution line and voltage signal V2 and current signal I2 at the load end; wherein, the source end is the first fault distance in the power distribution line and the load end is the second fault distance in the power distribution line.

[0086] S106. Perform FFT transformation on the source voltage signal V1 and current signal I1, and the load voltage signal V2 and current signal I2 respectively to obtain the frequency domain voltage signal and frequency domain current signal of the source and load.

[0087] S107. Substitute the first fault distance, the second fault distance, and the frequency domain voltage and current signals of the source and load ends into the positioning equation of the series arc fault location with the voltage and current signals to obtain the difference between the first fundamental frequency component and the second fundamental frequency component of the fault current; wherein, the difference between the first fundamental frequency component of the fault current is obtained by substituting the first fault distance into the positioning equation of the series arc fault location with the voltage and current signals, and the difference between the second fundamental frequency component of the fault current is obtained by substituting the second fault distance into the positioning equation of the series arc fault location with the voltage and current signals.

[0088] It should be noted that in the method of this embodiment, the fundamental frequency is the power frequency of 50Hz, and the difference in fundamental frequency components is the current value I flowing into the fault point. 1a With the fault point current value I 2a difference.

[0089] S108. Based on the difference between the first fundamental frequency component and the second fundamental frequency component of the fault current, the fault range is determined successively by approximation.

[0090] Optionally, the method provided in this embodiment of the invention specifically includes:

[0091] When the product of the difference between the first fundamental frequency component and the difference between the second fundamental frequency component of the fault current is less than zero, it is determined that the actual arc fault point is located between the first fault distance and the second fault distance.

[0092] Assume the arc fault point is half the distance between the first and second faults, and substitute it together with the frequency domain voltage and current signals of the source and load ends into the localization equation of the series arc fault location and the voltage and current signals to obtain the fundamental frequency component difference of the fault point.

[0093] If the product of the fundamental frequency component difference at the fault point and the second fundamental frequency component difference is less than zero, then the actual arc fault point is located between the assumed arc fault point and the second fault distance. Then, the value of the assumed fault point is assigned to the first fault distance, and the first fundamental frequency component difference is recalculated. If the product of the fundamental frequency component difference at the fault point and the first fundamental frequency component difference is less than zero, then the actual arc fault point is located between the first fault distance and the assumed arc fault point. Then, the value of the assumed arc fault point is assigned to the second fault distance, and the second fundamental frequency component difference is recalculated.

[0094] If the product of the difference between the first fundamental frequency component and the difference between the second fundamental frequency component remains less than zero, continue iterating and assume that the arc fault point is half of the first fault distance and the second fault distance.

[0095] S109. Within the determined fault range, determine the location of the arc fault point according to the set fault point search accuracy.

[0096] In the method provided by the embodiments of the present invention, when the difference between the first fault distance and the second fault distance is less than the set accuracy of searching for the fault point during the process of successively approximating the fault interval, the iterative process of determining the fault interval ends, and the actual arc fault point is obtained as half of the first fault distance and the second fault distance at this time.

[0097] Corresponding to the aforementioned embodiments of the SoC-based series AC arc fault detection method, this application also provides embodiments of the SoC-based series AC arc fault detection device.

[0098] refer to Figure 5 This invention also provides a SoC-based series AC arc fault detection device, comprising:

[0099] The signal acquisition unit is used to acquire voltage and current signals of different branches in the low-voltage power distribution system through the arc fault detection SoC chip;

[0100] The signal decomposition unit is used to perform wavelet decomposition on the voltage signals and current signals of the different branches respectively, to obtain the high-frequency components of the voltage signal and the high-frequency components of the current signal after wavelet decomposition.

[0101] The comparison unit is used to compare the high-frequency components of the voltage signal and the high-frequency components of the current signal with their respective preset thresholds;

[0102] The fault determination unit is used to determine whether an arc fault has occurred based on the comparison results in the current domain, and at the same time, to determine the fault branch by combining the comparison results in the voltage domain.

[0103] Corresponding to the aforementioned embodiments of the series AC arc fault location method, this application also provides embodiments of the series AC arc fault location device.

[0104] refer to Figure 6 This invention also provides a series AC arc fault location device, comprising:

[0105] An arc fault detection unit is used to execute the above-mentioned SoC-based series AC arc fault detection method.

[0106] The signal acquisition unit is used to acquire and record voltage and current signals at the source and load ends of the power distribution line through the arc fault detection SoC chip after the SoC-based series AC arc fault detection method is completed. The source end is the first fault distance in the power distribution line, and the load end is the second fault distance in the power distribution line.

[0107] The signal transformation unit is used to perform FFT transformation on the voltage signal and current signal at the source end and the load end respectively to obtain the frequency domain voltage signal and frequency domain current signal at the source end and the load end.

[0108] The difference calculation unit is used to substitute the first fault distance, the second fault distance, and the frequency domain voltage and current signals of the source and load ends into the positioning equation of the series arc fault location with the voltage and current signals to obtain the difference between the first fundamental frequency component and the second fundamental frequency component of the fault current; wherein, the difference between the first fundamental frequency component of the fault current is obtained by substituting the first fault distance into the positioning equation of the series arc fault location with the voltage and current signals, and the difference between the second fundamental frequency component of the fault current is obtained by substituting the second fault distance into the positioning equation of the series arc fault location with the voltage and current signals.

[0109] The successive approximation unit is used to successively approximate the fault range based on the difference between the first fundamental frequency component and the second fundamental frequency component of the fault current.

[0110] The fault point determination unit is used to determine the location of the arc fault point within a defined fault range, based on a set fault point search accuracy.

[0111] Regarding the apparatus in the above embodiments, the specific manner in which each module performs its operation has been described in detail in the embodiments related to the method, and will not be elaborated upon here.

[0112] For the device embodiments, since they basically correspond to the method embodiments, the relevant parts can be referred to in the description of the method embodiments. The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this application according to actual needs. Those skilled in the art can understand and implement this without creative effort.

[0113] Accordingly, this application also provides an electronic device, including: one or more processors; a memory for storing one or more programs; when the one or more programs are executed by the one or more processors, the one or more processors implement the SoC-based series AC arc fault detection method or series AC arc fault location method as described above.

[0114] Accordingly, this application also provides a computer-readable storage medium storing computer instructions thereon, which, when executed by a processor, implement the SoC-based series AC arc fault detection method or series AC arc fault location method as described above.

[0115] like Figure 7 The diagram illustrates an application scenario of SoC-based series AC arc fault detection and location in a complex low-voltage power distribution system with multiple branches, as provided in an embodiment of the present invention. F1-F4 in the diagram represent potential arc fault points. Such devices are installed in both the electricity meter and the household load. Figure 2 The SoC-based series AC arc fault detection structure 230 shown in the figure has an SoC chip located in the meter box that is always in working state to realize real-time monitoring of arc faults, while the SoC located in the load is waiting to be woken up.

[0116] Firstly, according to Figure 1 The illustrated embodiment of the arc fault detection method involves a SoC chip located in the meter box that collects and processes current signals I and voltage signals U from four channels. If abnormalities are detected in the voltage and current signals of all four branches, the arc fault occurs outside these four branches. If an abnormality is found only in the current signal of branch 3, the arc fault is determined to occur in branch 3, and a warning signal is issued. Simultaneously with the warning signal, the SoC chip located in load 3 is activated. The SoC chip in load 3 samples the voltage and current signals on the load side, while the SoC chip in the meter box collects the source voltage and current signals of branch 3. The collected source and load voltage and current signals are then simultaneously recorded in the host computer, and then... Figure 3 The specific execution process of S105 and subsequent steps quickly determines the location of the arc fault point in branch 3.

[0117] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the disclosure herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein. The specification and embodiments are to be considered exemplary only, and the true scope and spirit of this application are indicated by the claims.

[0118] It should be understood that this application is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this application is limited only by the appended claims.

Claims

1. A method for locating series AC arc faults, characterized in that, include: Implement a SoC-based method for detecting series AC arc faults; After the SoC-based series AC arc fault detection method is completed, the voltage and current signals at the source and load ends of the power distribution line are collected and recorded by the arc fault detection SoC chip, wherein the source end is the first fault distance in the power distribution line and the load end is the second fault distance in the power distribution line. Perform FFT transformation on the voltage and current signals at the source and load ends respectively to obtain the frequency domain voltage and current signals at the source and load ends. Substituting the first fault distance, the second fault distance, and the frequency domain voltage and current signals at the source and load ends into the location equation for the series arc fault location with respect to the voltage and current signals, the difference between the first and second fundamental frequency components of the fault current is obtained. The first fundamental frequency component difference of the fault current is obtained by substituting the first fault distance into the location equation for the series arc fault location with respect to the voltage and current signals, and the second fundamental frequency component difference of the fault current is obtained by substituting the second fault distance into the location equation for the series arc fault location with respect to the voltage and current signals. The fault range is determined by successively approximating the difference between the first fundamental frequency component and the second fundamental frequency component of the fault current. Within the defined fault range, the location of the arc fault point is determined according to the set accuracy of the fault point search. The SoC-based series AC arc fault detection method includes: The voltage and current signals of different branches in the low-voltage power distribution system are obtained through an arc fault detection SoC chip. Wavelet decomposition is performed on the voltage and current signals of the different branches to obtain the high-frequency components of the voltage and current signals after wavelet decomposition. The high-frequency components of the voltage signal and the high-frequency components of the current signal are compared with their respective set thresholds; The comparison results in the current domain are used to determine whether an arc fault has occurred. At the same time, the comparison results in the voltage domain are used to determine the fault branch.

2. The method according to claim 1, characterized in that, The step of performing wavelet decomposition on the voltage and current signals of the different branches to obtain the high-frequency components of the voltage and current signals after wavelet decomposition includes: Perform discrete wavelet transforms on the voltage and current signals of the different branches respectively; The high-frequency components of the voltage signal and the high-frequency components of the current signal after the first layer of decomposition are used as the high-frequency components of the voltage signal and the high-frequency components of the current signal after wavelet decomposition.

3. The method according to claim 1, characterized in that, The determination of whether an arc fault has occurred is based on the comparison results in the current domain. Simultaneously, the fault branch is judged by combining the comparison results in the voltage domain, including: When the peak value of the high-frequency component of the current signal exceeds a set threshold, an arc fault is determined to have occurred. When the peak value of the high-frequency component of the voltage signal also exceeds the set threshold, it is determined that the arc fault occurred outside the branch. If only the high-frequency component of the current signal exceeds the set threshold, it is determined that the arc fault occurred in that branch.

4. The method according to claim 1, characterized in that, The step of successively approximating the fault interval based on the difference between the first fundamental frequency component and the second fundamental frequency component of the fault current includes: When the product of the difference between the first fundamental frequency component and the difference between the second fundamental frequency component of the fault current is less than zero, it is determined that the actual arc fault point is located between the first fault distance and the second fault distance. Assume the arc fault point is half the distance between the first and second faults, and substitute it together with the frequency domain voltage and current signals of the source and load ends into the localization equation of the series arc fault location and the voltage and current signals to obtain the fundamental frequency component difference of the fault point. If the product of the fundamental frequency component difference at the fault point and the second fundamental frequency component difference is less than zero, then the actual arc fault point is located between the assumed arc fault point and the second fault distance. Then, the value of the assumed fault point is assigned to the first fault distance, and the first fundamental frequency component difference is recalculated. If the product of the fundamental frequency component difference at the fault point and the first fundamental frequency component difference is less than zero, then the actual arc fault point is located between the first fault distance and the assumed arc fault point. Then, the value of the assumed arc fault point is assigned to the second fault distance, and the second fundamental frequency component difference is recalculated. If the product of the difference between the first fundamental frequency component and the difference between the second fundamental frequency component remains less than zero, continue iterating and assume that the arc fault point is half of the first fault distance and the second fault distance.

5. The method according to claim 1, characterized in that, The step of determining the location of the arc fault point within a defined fault range, based on a set fault point search accuracy, includes: When the difference between the first fault distance and the second fault distance is less than the set accuracy of the fault point search during the process of successively approximating the fault range, the actual arc fault point is obtained as half of the first fault distance and the second fault distance at this time.

6. A series AC arc fault location device, characterized in that, include: An arc fault detection unit is used to execute a SoC-based series AC arc fault detection method. The signal acquisition unit is used to acquire and record voltage and current signals at the source and load ends of the power distribution line through the arc fault detection SoC chip after the SoC-based series AC arc fault detection method is completed. The source end is the first fault distance in the power distribution line, and the load end is the second fault distance in the power distribution line. The signal transformation unit is used to perform FFT transformation on the voltage signal and current signal at the source end and the load end respectively to obtain the frequency domain voltage signal and frequency domain current signal at the source end and the load end. The difference calculation unit is used to substitute the first fault distance, the second fault distance, and the frequency domain voltage and current signals of the source and load ends into the positioning equation of the series arc fault location with the voltage and current signals to obtain the difference between the first fundamental frequency component and the second fundamental frequency component of the fault current; wherein, the difference between the first fundamental frequency component of the fault current is obtained by substituting the first fault distance into the positioning equation of the series arc fault location with the voltage and current signals, and the difference between the second fundamental frequency component of the fault current is obtained by substituting the second fault distance into the positioning equation of the series arc fault location with the voltage and current signals. The successive approximation unit is used to successively approximate the fault range based on the difference between the first fundamental frequency component and the second fundamental frequency component of the fault current. The fault point determination unit is used to determine the location of the arc fault point within a defined fault range, based on a set fault point search accuracy. The SoC-based series AC arc fault detection method includes: The voltage and current signals of different branches in the low-voltage power distribution system are obtained through an arc fault detection SoC chip. Wavelet decomposition is performed on the voltage and current signals of the different branches to obtain the high-frequency components of the voltage and current signals after wavelet decomposition. The high-frequency components of the voltage signal and the high-frequency components of the current signal are compared with their respective set thresholds; The comparison results in the current domain are used to determine whether an arc fault has occurred. At the same time, the comparison results in the voltage domain are used to determine the fault branch.

7. An electronic device, characterized in that, include: One or more processors; Memory, used to store one or more programs; When the one or more programs are executed by the one or more processors, the one or more processors implement the method as described in any one of claims 1-5.

8. A computer-readable storage medium storing computer instructions thereon, characterized in that, When executed by the processor, this instruction implements the steps of the method as described in any one of claims 1-5.

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