Arc fault rapid detection method, system and storage medium

Abstract

The application discloses an arc fault rapid detection method, system and medium, and the method comprises the following steps: sampling a current differential signal in a to-be-detected line; calculating a fractal dimension of the current differential signal every 100 mu s in real time through sequentially recursive sampling points; comparing the real-time fractal dimension with an arc determination threshold DThld which is set based on an average value of the fractal dimension when the to-be-detected line is in normal operation; and if the real-time fractal dimension of ten consecutive times is all less than the arc determination threshold DThld set based on the average value of the fractal dimension when the to-be-detected line is in normal operation, it is determined that the to-be-detected line has an arc fault. Compared with the prior art, the application improves the arc fault detection speed, detection accuracy and anti-interference ability.

Description

Technical Field

[0001] This invention relates to the field of arc fault detection technology, and in particular to a rapid arc fault detection method, system and storage medium. Background Technology

[0002] In electrical systems of aircraft, ships, photovoltaic systems, and spacecraft, arcing can occur due to factors such as aging wiring, corrosion, loose connections, wear and degradation of switching devices over long-term operation, or environmental influences. Arcing poses a significant threat to the entire system; if the arc is not extinguished promptly, it can easily spread, burn out system components, and in severe cases, cause the entire system to fail. Spacecraft power systems are also affected by the space environment. Components exposed to the plasma environment, such as solar arrays and their conductive slip rings connected to the satellite, are susceptible to space charging and discharging effects, leading to space arcing and severely jeopardizing the safety of the entire satellite.

[0003] Currently, scholars both domestically and internationally have proposed various arc detection methods utilizing the characteristics of acoustic, optical, thermal, electromagnetic radiation, and electrical parameter changes accompanying arc discharge. These include remote detection methods based on electromagnetic radiation, detection methods based on the time-domain or frequency-domain characteristics of arc fault current, and high-precision intelligent detection methods. Each of these arc fault detection methods has its own advantages, is suitable for different application scenarios, and meets diverse detection needs. For arc faults in power supply and distribution lines, patent CN103163353A proposes an arc fault detection method based on current waveform phase space reconstruction and fractal theory. This method distinguishes fault current signals by reconstructing the phase space of the complete current cycle signal and calculating the box-counting dimension of the phase space trajectory diagram.

[0004] Among the methods described above, remote detection is significantly affected by environmental factors, limiting its application scenarios. Methods based on current or voltage time-domain thresholds offer the fastest detection time but are prone to false positives. While intelligent algorithms and phase-space reconstruction methods improve detection accuracy, their detection speed is slow, taking milliseconds or longer. None of these methods can simultaneously meet the requirements of both speed and accuracy, making them unsuitable for applications requiring rapid arc extinguishing. For example, in spacecraft, an arc fault in the conductive slip rings, if not extinguished within microseconds, can cause the fault to spread along each slip ring, affecting energy transfer in the solar array and potentially even burning out the solar panels, leading to complete satellite power loss in severe cases. Therefore, while maintaining high detection accuracy and strong anti-interference capabilities, a faster arc fault detection technology is needed. Summary of the Invention

[0005] The main objective of this invention is to propose a method, system, and storage medium for rapid detection of electric arc faults, aiming to achieve rapid detection of electric arc faults and improve detection accuracy and anti-interference capability.

[0006] To achieve the above objectives, the present invention provides a rapid detection method for electric arc faults, the method comprising the following steps:

[0007] Step S10: Sample the differential current signal in the circuit under test;

[0008] Step S20: Calculate the fractal dimension of the current differential signal every 100μs in real time by recursively calculating one sampling point at a time.

[0009] Step S30: The real-time fractal dimension is compared with the arc determination threshold DThld, which is pre-set based on the average value of the fractal dimension when the circuit under test is working normally.

[0010] Step S40: If ten consecutive real-time fractal dimensions are all less than the arc determination threshold DThld set based on the average value of the fractal dimensions when the line under test is working normally, then the line under test is determined to have an arc fault.

[0011] A further technical solution of the present invention is that, after step S30, it further includes:

[0012] If the ten consecutive real-time fractal dimensions are not all less than the arc determination threshold DThld set based on the average value of the fractal dimensions when the circuit under test is working normally, then return to execute step S30.

[0013] A further technical solution of the present invention is that, after step S20 and before step S30, the following is included:

[0014] The arc detection threshold DThld is pre-set based on the average value of the fractal dimension when the circuit under test is working normally.

[0015] A further technical solution of the present invention is that the arc determination threshold DThld is set according to the configuration parameters of the circuit under test and the safety level of the arc fault.

[0016] To achieve the above objectives, the present invention also proposes a rapid arc fault detection system, the system comprising a memory, a processor, and a rapid arc fault detection program stored on the processor, wherein the rapid arc fault detection program is executed by the processor to perform the following steps:

[0017] Step S10: Sample the differential current signal in the circuit under test;

[0018] Step S20: Calculate the fractal dimension of the current differential signal every 100μs in real time by recursively calculating one sampling point at a time.

[0019] Step S30: The real-time fractal dimension is compared with the arc determination threshold DThld, which is pre-set based on the average value of the fractal dimension when the circuit under test is working normally.

[0020] Step S40: If ten consecutive real-time fractal dimensions are all less than the arc determination threshold DThld set based on the average value of the fractal dimensions when the line under test is working normally, then the line under test is determined to have an arc fault.

[0021] A further technical solution of the present invention is that, when the arc fault rapid detection program is run by the processor, it further performs the following steps:

[0022] If the ten consecutive real-time fractal dimensions are not all less than the arc determination threshold DThld set based on the average value of the fractal dimensions when the circuit under test is working normally, then return to execute step S30.

[0023] A further technical solution of the present invention is that, when the arc fault rapid detection program is run by the processor, it further performs the following steps:

[0024] The arc detection threshold DThld is pre-set based on the average value of the fractal dimension when the circuit under test is working normally.

[0025] A further technical solution of the present invention is that the arc determination threshold DThld is set according to the configuration parameters of the circuit under test and the safety level of the arc fault.

[0026] To achieve the above objectives, the present invention also proposes a computer-readable storage medium storing an arc fault rapid detection program, wherein the arc fault rapid detection program is executed by a processor to perform the steps described in the above embodiments.

[0027] The beneficial effects of the rapid arc fault detection method, system, and storage medium of the present invention are:

[0028] 1. The significant difference between the fractal dimension values ​​of the current differential signal during normal system operation and the fractal dimension values ​​of the fault current differential signal is used as the basis for arc judgment. Compared with a single time-domain criterion, this reduces misjudgments and improves detection accuracy.

[0029] 2: By calculating the fractal dimension of equally spaced sampling points in real time, arc faults are identified, which greatly improves the detection speed and can detect arc faults in microseconds.

[0030] 3: By improving the fractal dimension threshold determination algorithm, this real-time fast detection method can be applied to arc detection in AC systems. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0032] Figure 1 This is a flowchart illustrating a preferred embodiment of the rapid arc fault detection method of the present invention;

[0033] Figure 2 This is a diagram of the hardware architecture for the rapid detection method for electric arc faults of the present invention.

[0034] Figure 3 This is a schematic diagram of parallel arc sampling points;

[0035] Figure 4 This is a schematic diagram of the series arc sampling points;

[0036] Figure 5 This is a schematic diagram of the overall process of the rapid detection method for electric arc faults of the present invention;

[0037] Figure 6 This is a schematic diagram of the continuous dimension determination result in a preferred embodiment of the rapid arc fault detection method of the present invention;

[0038] Figure 7 This is a schematic diagram of the CT sampling time domain points in a preferred embodiment of the rapid arc fault detection method of the present invention;

[0039] Figure 8 This is a schematic diagram of the continuous dimension determination results in arc fault detection of AC systems;

[0040] Figure 9 This is a schematic diagram of the time-domain sampling points of the CT in the arc fault detection of an AC system.

[0041] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0042] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0043] This invention proposes a rapid arc fault detection method, which is applicable to the detection of arc faults that may occur in various electrical systems, such as inverters, relays, sockets, and power supplies. It is particularly relevant to power supply systems in the aerospace field, where both fault detection accuracy and speed are extremely important.

[0044] like Figure 1 As shown, a preferred embodiment of the rapid arc fault detection method of the present invention includes the following steps:

[0045] Step S10: Sample the differential current signal in the circuit under test.

[0046] Specifically, in this embodiment, the differential current signal in the circuit under test can be sampled using a current transformer.

[0047] Step S20: The fractal dimension of the current differential signal per 100μs is calculated in real time by recursively calculating one sampling point at a time.

[0048] Fractal geometry is a branch of mathematics that describes complex forms in nature; it is a mathematical method used to describe irregularly shaped objects. Fractal dimension is used to represent different fractal characteristics, and the box dimension is used for calculation. Its definition is as follows: Let F be a representation of R... n Given a bounded subset of a set, take a box with side length ε and cover it with a fractal function F. Calculate the number of boxes that fill the set: N. ε (F); Further reduce the volume of the box, at this time the quantity (N) ε (F) will gradually increase, and when ε gradually approaches 0, the calculated fractal dimension is obtained, denoted as D. B :

[0049]

[0050] In practice, by calculating a series of ε and N ε (F), each performs logarithmic calculations, and fits a linear relationship using the least squares method through a series of coordinates. The slope value is the fractal dimension.

[0051] During normal system operation, the fractal dimension of the measured line current differential signal remains within a stable range over the same period. However, the fractal dimension of the arc fault current differential signal exhibits significant differences over the same period. Based on this characteristic, the fractal dimension of the current differential signal every 100μs can be calculated in real time by sequentially iterating through each sampling point. By detecting real-time changes in the fractal dimension, arc faults can be quickly identified, significantly reducing arc detection time.

[0052] Step S30: The real-time fractal dimension is compared with the arc determination threshold DThld, which is pre-set based on the average value of the fractal dimension when the circuit under test is working normally.

[0053] Step S40: If ten consecutive real-time fractal dimensions are all less than the arc determination threshold DThld set based on the average value of the fractal dimensions when the line under test is working normally, then the line under test is determined to have an arc fault.

[0054] In this embodiment, the method further includes the following after step S30:

[0055] If the ten consecutive real-time fractal dimensions are not all less than the arc determination threshold DThld set based on the average value of the fractal dimensions when the circuit under test is working normally, then return to execute step S30.

[0056] In this embodiment, the steps after S20 and before S30 include:

[0057] The arc detection threshold DThld is pre-set based on the average value of the fractal dimension when the circuit under test is working normally.

[0058] The arc detection threshold DThld is set based on the configuration parameters of the circuit under test and the safety level of the arc fault. Generally, it is the average value of the fractal dimension Davg within 1 ms when the circuit under test is working normally, multiplied by the threshold coefficient A, i.e., DThld = A * Davg.

[0059] As a preferred embodiment, in this embodiment, the arc determination threshold DThld is 93% of the average value of 1000 consecutive fractal dimensions when the circuit under test is working normally.

[0060] The following combination Figures 2 to 9 The rapid detection method for electric arc faults of the present invention will be further described in detail.

[0061] Figure 2 This is a diagram of the operational hardware architecture of the rapid arc fault detection method of the present invention. The operational hardware architecture of the rapid arc fault detection method of the present invention includes the circuit under test (detection points for series arcs and parallel arcs, such as...) Figure 3 and Figure 4 As shown), a current transformer and an FPGA signal processing module are used. The current sensor is used to detect the AC differential signal of the circuit in the system under test. The sampling data is then processed by the signal processing module to calculate the fractal dimension value of the current differential signal every 100μs in real time, and the arc fault is determined by the fractal dimension threshold.

[0062] The implementation process of the rapid arc fault detection method of the present invention is as follows (please refer to...). Figure 5 ):

[0063] Step 1: Use a current transformer to sample the differential current signal in the circuit under test;

[0064] Step 2: Calculate the fractal dimension of the current differential signal every 100μs in real time by iteratively calculating one sampling point at a time.

[0065] Step 3: Set the arc detection threshold based on the average fractal dimension when the system is working normally, such as... Figure 6 and Figure 7 As shown, Figure 6 and Figure 7 The threshold DThld is set to 93% of the average of 1000 consecutive fractal dimensions;

[0066] Step 4: Determine the arc fault based on the threshold DThld. If 10 consecutive dimension values ​​are lower than the threshold, the system is determined to have an arc fault.

[0067] It should be noted that the rapid arc fault detection method of the present invention, through an improved fractal dimension threshold determination algorithm, can be applied to arc fault detection in AC systems, such as... Figure 8 and Figure 9 As shown.

[0068] The beneficial effects of the rapid arc fault detection method of the present invention are:

[0069] 1. The significant difference between the fractal dimension values ​​of the current differential signal during normal system operation and the fractal dimension values ​​of the fault current differential signal is used as the basis for arc judgment. Compared with a single time-domain criterion, this reduces misjudgments and improves detection accuracy.

[0070] 2: By calculating the fractal dimension of equally spaced sampling points in real time, arc faults are identified, which greatly improves the detection speed and can detect arc faults in microseconds.

[0071] 3: By improving the fractal dimension threshold determination algorithm, this real-time fast detection method can be applied to arc detection in AC systems.

[0072] To achieve the above objectives, the present invention also proposes a rapid arc fault detection system, the system comprising a memory, a processor, and a rapid arc fault detection program stored on the processor, wherein the rapid arc fault detection program is executed by the processor to perform the following steps:

[0073] Step S10: Sample the differential current signal in the circuit under test.

[0074] Step S20: The fractal dimension of the current differential signal per 100μs is calculated in real time by recursively calculating one sampling point at a time.

[0075] Step S30: The real-time fractal dimension is compared with the arc determination threshold DThld, which is pre-set based on the average value of the fractal dimension when the circuit under test is working normally.

[0076] Step S40: If ten consecutive real-time fractal dimensions are all less than the arc determination threshold DThld set based on the average value of the fractal dimensions when the line under test is working normally, then the line under test is determined to have an arc fault.

[0077] Furthermore, when the arc fault rapid detection program is run by the processor, it also performs the following steps:

[0078] If the ten consecutive real-time fractal dimensions are not all lower than the arc determination threshold DThld set based on the average value of the fractal dimensions when the circuit under test is working normally, then return to execute step S30.

[0079] Furthermore, when the arc fault rapid detection program is run by the processor, it also performs the following steps:

[0080] The arc detection threshold DThld is pre-set based on the average value of the fractal dimension when the circuit under test is working normally.

[0081] Furthermore, the arc detection threshold DThld is set according to the configuration parameters of the circuit under test and the safety level of the arc fault.

[0082] The beneficial effects of the arc fault rapid detection system of the present invention are:

[0083] 1. The significant difference between the fractal dimension values ​​of the current differential signal during normal system operation and the fractal dimension values ​​of the fault current differential signal is used as the basis for arc judgment. Compared with a single time-domain criterion, this reduces misjudgments and improves detection accuracy.

[0084] 2: By calculating the fractal dimension of equally spaced sampling points in real time, arc faults are identified, which greatly improves the detection speed and can detect arc faults in microseconds.

[0085] 3: By improving the fractal dimension threshold determination algorithm, this real-time fast detection method can be applied to arc detection in AC systems.

[0086] To achieve the above objectives, the present invention also proposes a computer-readable storage medium storing an arc fault rapid detection program. When the arc fault rapid detection program is run by a processor, it executes the steps described in the above embodiments, which will not be repeated here.

[0087] The above description is only a preferred embodiment of the present invention and does not limit the patent scope of the present invention. All equivalent structural transformations made under the concept of the present invention using the contents of the present invention specification and drawings, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A method of arc fault rapid detection, comprising: The method comprises the following steps: Step S10, sampling the current differential signal in the to-be-tested line through a current transformer; Step S20, calculating the fractal dimension of the current differential signal every 100 μs in real time by sequentially extrapolating one sampling point; Step S30, comparing the real-time fractal dimension with an arc determination threshold DThld set in advance based on the average value of the fractal dimension when the to-be-tested line is in normal operation; Step S40, if the ten consecutive real-time fractal dimensions are all less than the arc determination threshold DThld set based on the average value of the fractal dimension when the to-be-tested line is in normal operation, determining that the to-be-tested line has an arc fault; if the ten consecutive real-time fractal dimensions are not all less than the arc determination threshold DThld set based on the average value of the fractal dimension when the to-be-tested line is in normal operation, returning to execute the step S30.

2. The arc fault rapid detection method of claim 1, wherein, After the step S20 and before the step S30, the following step is included: Setting the arc determination threshold DThld in advance based on the average value of the fractal dimension when the to-be-tested line is in normal operation.

3. The arc fault fast detection method of claim 2, wherein, The arc determination threshold DThld is set according to the configuration parameters of the to-be-tested line and the safety level of the arc fault.

4. An arc fault rapid detection system characterized by, The system comprises a memory, a processor, and an arc fault rapid detection program stored on the processor, and the arc fault rapid detection program performs the following steps when executed by the processor: Step S10, sampling the current differential signal in the to-be-tested line through a current transformer; Step S20, calculating the fractal dimension of the current differential signal every 100 μs in real time by sequentially extrapolating one sampling point; Step S30, comparing the real-time fractal dimension with an arc determination threshold DThld set in advance based on the average value of the fractal dimension when the to-be-tested line is in normal operation; Step S40, if the ten consecutive real-time fractal dimensions are all less than the arc determination threshold DThld set based on the average value of the fractal dimension when the to-be-tested line is in normal operation, determining that the to-be-tested line has an arc fault; if the ten consecutive real-time fractal dimensions are not all less than the arc determination threshold DThld set based on the average value of the fractal dimension when the to-be-tested line is in normal operation, returning to execute the step S30.

5. The arc fault fast detection system of claim 4, wherein, The arc fault rapid detection program executed by the processor further performs the following step: Setting the arc determination threshold DThld in advance based on the average value of the fractal dimension when the to-be-tested line is in normal operation.

6. The arc fault rapid detection system according to claim 5, wherein the arc determination threshold DThld is set according to the configuration parameters of the to-be-tested line and the safety level of the arc fault.

7. A computer readable storage medium characterized in that, The computer readable storage medium stores an arc fault rapid detection program, and the arc fault rapid detection program performs the steps of the method according to any one of claims 1 to 3 when executed by a processor.

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