Arc detection device with multi-frequency band discrimination function

Abstract

The present invention proposes an arc detection device with a multiple frequency band discrimination function that divides an arc frequency band using multiple band pass filters and detects the occurrence of an arc for each divided frequency band, thereby removing switching noise and power supply noise that mainly occur only in a specific frequency band, thereby improving the accuracy of arc detection, while minimizing the use of expensive analog / digital converters, and increasing the accuracy of arc determination by detecting overlapping bands.To this end, the present invention provides an arc detection device with a multiple frequency band discrimination function that is connected to a line and applies a low pass filter, at least one band pass filter, and a high pass filter to a frequency band in which an arc is expected to occur, thereby dividing the frequency band into multiple detection bands and detecting the arc.

Description

[Technical Field]

[0001] The present invention relates to an arc detection device provided with a multi-frequency band discrimination function, and more particularly to an arc detection device provided with a multi-frequency band discrimination function that minimizes false detection caused by switching noise or inverter noise similar to an arc by dividing an arc frequency band in which an arc occurs into a plurality of bands and detecting an arc for each of the divided frequency bands. [Background Art]

[0002] An arc is intense light and heat generated when a current flows with gas as a medium between two physically separated electrodes.

[0003] Arcs can be roughly classified into series arcs occurring within one conductor, parallel arcs occurring between two conductors, and grounding arcs occurring between the ground and one conductor.

[0004] Here, a series arc is an arc fault that occurs when the connection of a line or contact through which current should normally flow becomes weak. Since such a series arc does not form a current zero point, natural arc extinction is difficult, which not only poses high danger, but also brings difficulties in accident detection.

[0005] As described above, series arc accidents may occur due to aged deterioration of lines, poor contact of connectors, and the like. In the case of such a series arc accident, despite the occurrence of the accident, the magnitude of the accident current is within the normal operating range, so it is difficult to detect with a general overcurrent circuit breaker or residual current circuit breaker. [Summary of the Invention] [Problem to be Solved by the Invention]

[0006] The object of the present invention is to provide an arc detection device equipped with a multi-frequency band discrimination function that minimizes false detections caused by switching noise and noise generated during power conversion by dividing the arc frequency band in which an arc occurs into multiple bands and detecting whether or not the same arc is occurring in each of the divided frequency bands.

[0007] Another object of the present invention is to provide an arc detection device with a multi-frequency band discrimination function that minimizes the use of a fast and expensive ADC (Analog to Digital Converter) by detecting arcs in the arc frequency band using a band-pass filter and a comparator. [Means for solving the problem]

[0008] The above objective is achieved, according to the present invention, by an arc detection device equipped with a multi-frequency band discrimination function that detects the arc by applying a low-pass filter, at least one band-pass filter, and a high-pass filter to a frequency band connected to a power line where arc generation is expected, thereby dividing the frequency band into a plurality of detection bands. [Effects of the Invention]

[0009] According to the present invention, the quality of electricity flowing through the railway tracks can be constantly monitored.

[0010] Furthermore, according to the present invention, by dividing the arc frequency band using multiple band-pass filters and detecting the presence or absence of arcs in each divided frequency band, switching noise and power supply noise that mainly occur only in specific frequency bands can be removed, thereby improving the accuracy of arc detection.

[0011] Furthermore, according to the present invention, the use of expensive analog-to-digital converters that operate at high speed while applying band-pass filtering to multiple frequencies is minimized. This reduces the manufacturing cost of an arc detection device with overall multi-frequency band discrimination capabilities, while further improving performance by dividing the arc detection process for each frequency band. [Brief explanation of the drawing]

[0012] [Figure 1] This is a block diagram of an arc detection device equipped with a multi-frequency band discrimination function according to one embodiment of the present invention. [Figure 2] This is a reference diagram illustrating an example where the frequency bands of low-pass filters, band-pass filters, and high-pass filters are clearly distinguished. [Figure 3] This is a reference diagram illustrating an example of a band-pass filter configured so that its passband and adjacent frequency bands overlap. [Figure 4] This is a reference diagram illustrating an example of excluding arc detection in frequency bands where switching noise and impulses frequently occur. [Figure 5] This figure shows an example of a reference voltage set for a comparator connected to a band-pass filter. [Figure 6] This figure shows an example of a reference voltage set for a comparator connected to a band-pass filter. [Figure 7] This figure shows an example of the switching waveform of a power supply connected to a transmission line. [Figure 8] This figure shows an example of a signal containing both arc and inverter noise. [Modes for carrying out the invention]

[0013] The arc frequency band referred to herein may refer to all frequency bands. However, for the sake of understanding and convenience, this specification will focus primarily on embodiments from 0 Hz to 150 kHz. It should be noted that the arc frequency band is not limited to the embodiments referred to herein.

[0014] The band-pass filters mentioned in this specification may be a general term for low-pass filters, band-pass filters, and high-pass filters based on the arc frequency band. Unless otherwise specified, the term may refer to all of low-pass filters, band-pass filters, and high-pass filters; when specifically mentioned separately, low-pass filters or high-pass filters will be used instead of band-pass filters and described separately in some cases.

[0015] Hereinafter, the present invention will be described in detail with reference to the drawings.

[0016] Fig. 1 is a block conceptual diagram of an arc detection device provided with a multi-frequency band discrimination function according to an embodiment of the present invention.

[0017] Referring to Fig. 1, the arc detection device provided with a multi-frequency band discrimination function according to an embodiment may be configured to include a current sensor 50, a band detection unit 100, an arithmetic unit 200, and a circuit breaker 300, and the arithmetic unit 200 may be configured by a signal processing unit 210 and an arc determination unit 220.

[0018] The current sensor 50 may be formed of current measuring elements such as a shunt resistor, a current transformer (CT) sensor, and a Hall sensor.

[0019] The current sensor 50 is directly connected to either one of a pair of lines 10. The current sensor 50 calculates a current value flowing through the line 10 with reference to a voltage value generated by the current measuring element. Further, the current sensor 50 can provide the band detection unit 100 with a voltage value corresponding to the current generated by the current measuring element.

[0020] The band detection unit 100 detects an arc based on a voltage value corresponding to a current flowing through the line 10 via the current sensor 50. The band detection unit 100 divides an arc frequency band into a plurality of detection bands, and includes a low-pass filter 110a, band-pass filters 110b to 110n, or a high-pass filter 111) according to each detection band.

[0021] According to the embodiment, the arc frequency band can be divided into frequency bands in accordance with the items described below.

[0022] 1) Low frequency band: 0 hz to 40 khz 2) Frequency band of the band-pass filter: 40 khz to 100 khz 3) High frequency band: 100 kHz or higher

[0023] In the present embodiment, the low frequency band corresponds to the frequency band in which an arc is generated most strongly. It also corresponds to the frequency band in which the largest amount of switching noise occurs.

[0024] For the low frequency band, frequency conversion may be separately performed by an analog-to-digital converter and Fourier transform or fast Fourier transform, so as to distinguish between an arc and a non-arc impulse. A low-pass filter 110a is provided for the low frequency band, which will be described later.

[0025] The band of the band-pass filter corresponds to 40 kHz to 100 kHz, and the frequency band can be divided into one, two, or more bands. In FIG. 1, the band-pass filters correspond to reference numerals 110b to 110n.

[0026] The high frequency band corresponds to a frequency band of 100 kHz or higher, and the high-pass filter 111 is in charge of arc detection.

[0027] Arcs generated on railway tracks occur across all frequency bands, including low-frequency, high-frequency, and band-pass filter frequency bands. However, unlike switching noise and impulses, which occur only in specific frequency bands, arcs occur across the entire arc frequency band.

[0028] On the other hand, the frequency bands of the low-pass filter 110a, the band-pass filters 110b to 110n, and the high-pass filter 111 may be independent of each other or may partially overlap. This will be explained with reference to Figures 2 to 4.

[0029] Figure 2 shows an example in which the frequency bands of the low-pass filter 110a, the band-pass filters 110b to 110n, and the high-pass filter 111 are clearly distinguished.

[0030] In Figure 2, it can be seen that the frequency bands are divided such that the low-pass filter 110a passes only the frequency band from 0 Hz to 40 kHz, the band-pass filters 110b to 110n pass only the frequency band from 40 kHz to 100 kHz, and the high-pass filter 111 passes only the frequency band above 100 kHz.

[0031] The success of the method for clearly dividing the arc frequency band using the low-pass filter 110a, the band-pass filters 110b to 110n, and the high-pass filter 111 can be determined by the quality of the filter gain of the band-pass filters. The filter gain characteristics will be explained with reference to Table 1 below.

[0032] [Table 1]

[0033] As shown in Table 1, the gain of the low-pass filter 110a decreases as the frequency increases, and the gain at point a1 is reduced to about half of its maximum value. As a result, when an arc occurs in the frequency band corresponding to point a1 of the low-pass filter 110a, the maximum signal value of the generated arc can be received at approximately half its original value.

[0034] As shown in Table 1, the gain of the band-pass filters 110b to 110n decreases significantly at frequencies lower than the frequency corresponding to point a2 and higher than the frequency corresponding to point a2'. While the band-pass filters 110b to 110n can guarantee good reception gain in the frequency band between point a2 and point a2', if an arc occurs at a frequency lower than point a2 or higher than point a2', the signal value of the received arc will decrease significantly and may not be recognized as an arc.

[0035] As shown in Table 1, the high-pass filter 111 exhibits a gain characteristic where the gain at frequencies lower than point a3 is lower than the maximum value. If an arc occurs at a frequency corresponding to point a3 or lower, the maximum signal value of the generated arc may be judged as too low and may not be recognized as an arc.

[0036] Based on Table 1 above, the signal gains of the low-pass filter 110a, the band-pass filters 110b to 110n, and the high-pass filter 111 have been described. To solve this problem, the applicant of the present invention proposes a method for adjusting the frequency bands assigned to the low-pass filter, high-pass filter, and band-pass filters 110a to 111, as shown in Figures 3 and 4.

[0037] Referring also to Figure 3, the filter bandwidth for the arc frequency band can be realized in a form that overlaps with adjacent frequency bands.

[0038] As shown in Figure 3, the frequency band may be divided and assigned such that the low-pass filter 110a filters the frequency band from 0 Hz to 45 kHz, the band-pass filters 110b to 110n filter the frequency band from 35 kHz to 110 kHz, and the high-pass filter 111 filters the frequency band above 90 kHz.

[0039] The low-pass filter 110a is further extended compared to the frequency band shown in Figure 2, filtering the frequency band from 0 Hz to 45 kHz. Point a1 shown in Table 1 is extended to the right on the frequency axis, which is equivalent to widening the frequency band of the low-pass filter.

[0040] The high-pass filter 111 is extended to the lower frequency band beyond the frequency band shown in Figure 2, allowing it to pass frequencies above 90 kHz, thereby ensuring the signal gain for the 100 kHz frequency band it originally handled.

[0041] In Figure 3, bands 1 and 2 have overlapping frequency domains. The frequency band of the low-pass filter 110a is responsible for band 1 and the overlapping band b1, and the arc frequency bands are divided so that the band-pass filters 110b to 110n also receive the overlapping band b1. Similarly, the band-pass filters 110b to 110n are configured to filter the overlapping band b2 from the frequency band corresponding to band 2 and the frequency band that was handled by the high-pass filter 111. As a result, the overlapping bands b1 and b2 are filtered so as to overlap with the filters that process adjacent frequency bands, so that no frequency band is lost for arc detection and arc detection can be determined across the entire band.

[0042] On the other hand, the detection bandwidth may be configured in a way that excludes a specific frequency band, as shown in Figure 4.

[0043] Figure 4 is a reference diagram illustrating an example of excluding arc detection in a frequency band where switching noise and impulses frequently occur.

[0044] In Figure 4, the frequency band from 30kHz to 50kHz is excluded from arc detection. This is because, in electrical equipment to which the arc detection device equipped with the multi-frequency band discrimination function according to the embodiment is applied, unwanted noise is generated in the 30kHz to 50kHz frequency band that may be mistakenly detected as an arc. This is to prevent the arc detection device from making false detections by excluding the frequency band in which noise caused by the load connected to the line 10 exists from arc detection.

[0045] The method for excluding the frequency band shown in Figure 4 from the detection band is determined according to the noise characteristics of the entire electrical system, and the example frequency band (30kHz to 50kHz) may differ depending on the electrical equipment to which the arc detection device equipped with the multi-frequency band discrimination function according to this embodiment is connected.

[0046] The characteristics of the low-pass filter 110a, the band-pass filters 110b to 110n, and the high-pass filter 111 have been described above. The remaining components of the band detection unit 100 will now be described.

[0047] First, the low-pass filter 110a acquires the frequency band corresponding to the low-frequency band from the sensing value of the current sensor 50, and then transmits it to the arc detection unit 200.

[0048] The output values ​​of the band-pass filters 110b to 110n are individually provided to the signal processing unit 210. In Figure 1, the signal processing unit 210 can compare the output value of the band-pass filter 110b with a reference value set by the user and output the comparison result. It is also possible to compare the output values ​​of the band-pass filters 110b to 110n using multiple reference voltages instead of a single reference voltage and generate separate comparison values.

[0049] For the purpose of arc detection, the output value of the band-pass filter 110b may be compared with a reference voltage to determine whether or not an arc is occurring.

[0050] The signal processing unit 210 may be configured to compare the output value of the band-pass filter 110b with a reference voltage, and if a voltage greater than the reference voltage is applied from the band-pass filter 110b, it may determine that an arc is occurring and output a logical value of "1".

[0051] Similarly, the signal processing unit 210 can detect the occurrence of an arc by comparing the output value of the band-pass filter 110n with a reference voltage, and outputting a logical value "1" if the output value is greater than the reference voltage.

[0052] The same applies to the high-pass filter 111. The signal processing unit 210 compares the output value of the high-pass filter 111 with the reference voltage set for the high-pass filter 111 and outputs a logical value of "0" or "1" depending on the comparison result, thereby detecting the occurrence of an arc.

[0053] Furthermore, the signal processing unit 210 can also compare the output values ​​of each of the filters 110b to 110n that constitute the bandwidth detection unit 100 with different reference voltages, and generate power quality evaluation data for the power flowing through the transmission line 10, in addition to arc detection.

[0054] For example, the signal processing unit 210 can use the output value of the band-pass filter 110b for arc detection by comparing it with reference voltage 1, and it can also use the output value of the band-pass filter 110b for measuring the quality of power passing through the transmission line 10 by comparing it with reference voltages 2, 3, and n, respectively.

[0055] Here, the reference voltage required for arc detection (reference voltage 1) and the reference voltages used for power quality measurement (reference voltages 2 to n) may be different voltages, and it is preferable that they be set lower than the arc voltage. This will be explained with reference to Figures 5 and 6.

[0056] Figures 5 and 6 show an example of a reference voltage compared to the output value of the bandpass filter 110b.

[0057] In Figure 5, RV1 to RVn are shown as examples of reference voltages of the signal processing unit 210. The dual reference voltage RV1 is used for arc detection, and the explanation will be based on the assumption that the voltage passing through the transmission line 10 is DC (DC).

[0058] For the DC (DC) passing through the line 10, the signal processing unit 210 associates it with multiple reference voltages RV1 to RVn and determines the result of comparing it with each of the reference voltages RV1 to RVn. For example, if the DC (DC) has a waveform as shown in Figure 5, the signal processing unit 210 outputs a logical value of "1" for reference voltage RV4 at t1, t2, and t3, but outputs a logical value of "0" at t4 and t5, and outputs a logical value of "1" at t6.

[0059] The fact that the logical values ​​1, 1, 1, 1, 0, 0, 0, 1 are output at regular time intervals along the time axis t, means that the quality of the DC (DC) is not uniform, and even assuming that the DC (DC) current value is constant, it means that the quality of the power supply flowing through line 10 deteriorates in proportion to the change in DC (DC).

[0060] Next, Figure 6 shows another example of a DC waveform flowing through a railway line.

[0061] The waveform in Figure 6 shows an example that includes power supply noise generated when converting AC to DC.

[0062] Referring to Figure 6, the DC current w1 containing power supply noise exceeds the reference voltage RV1 at points P1 and P2, and is detected as a logical value of "1" when compared with the reference voltage RV1.

[0063] However, in comparisons with other reference voltages RV2~RVn, DC w1 is not detected because it is smaller than the other reference voltages RV2~RVn.

[0064] On the other hand, in Figure 6, the DC w2 is detected in the signal processing unit 210 after being compared with the reference voltages RV1 to RV3.

[0065] In other words, in DC w2, a switching noise with a high maximum value relative to the expected fundamental voltage ref is continuously detected, indicating that the quality of DC w2 is lower than that of DC w1.

[0066] The quality of DC will be explained with reference to Figures 7 and 8.

[0067] Of the two graphs shown in Figure 7, the upper graph shows the switching waveform of the power supply connected to the transmission line 10, and the lower graph shows the DC output current waveform of the power supply.

[0068] As shown in Figure 7, the power supply unit that supplies DC to the transmission line 10 has the characteristic of repeatedly generating pulses of a constant magnitude and frequency during the process of switching AC to convert it to DC when no arc is generated. Each time the AC is sliced, a triangular wave-shaped current waveform flows into the transmission line 10, and such a current waveform is characterized by being observed in a specific frequency band (mainly occurring in the 100kHz band). Such a waveform, which occurs regularly with a constant magnitude in a specific frequency band, does not need to be judged as an arc.

[0069] Figure 8 shows an example of a signal containing both arc and inverter noise.

[0070] Referring to Figure 8, it can be seen that arcs occur across the entire arc frequency band, with particularly large amplitudes in the low-frequency band.

[0071] On the other hand, switching noise generated from the inverter was observed only in the 15kHz, 33kHz, and 48kHz bandwidths, and its amplitude was similar to that of an arc.

[0072] The switching noise generated by the inverter occurs in three locations, unlike what is shown in Figure 6, because the inverter changes its switching period to maintain the output voltage.

[0073] When the quality of the voltage flowing through the transmission line 10, i.e., the quality of the power, changes drastically, the inverter maintains a constant voltage through the transmission line 10 by varying the switching noise. However, looking at the graph in Figure 7, which is defined by the relationship between frequency and amplitude, only three peak amplitudes IV1, IV2, and IV3 are observed. When defined by the time axis and amplitude, at any given time, only one of the inverter switching noises IV1, IV2, or IV3 occurs, and the other two noises do not appear.

[0074] In other words, when the band detection unit 100 detects an arc over time in the arc frequency band, only one switching noise is detected. That is, the switching noise of the inverter is considered as a single impulse and does not occur across the entire frequency band of the arc frequency band.

[0075] The arc waveform and non-arc waveform flowing through the transmission line 10 have been described above with reference to Figures 7 and 8. The arc detection unit 220 will now be described.

[0076] The arc detection unit 200 compares the filtering result value of the bandwidth detection unit 100 with a plurality of reference voltages provided in the signal processing unit 210, receives the comparison result, and counts each of the filters 110a to 111 provided in the bandwidth detection unit 100. For example, the output value of the bandwidth-pass filter 110b may be compared with a single reference voltage, but for power quality measurement, arc detection and power quality measurement can be performed simultaneously by comparing with two or more reference voltages.

[0077] The arc detection unit 200 may, after counting the number of times the voltage exceeds the reference voltage applied to each filter 110a to 111, determine that an arc is occurring if the counted value exceeds a preset reference value.

[0078] If the only determination is whether or not an arc is occurring, the arc determination unit 200 may compare the output values ​​from each filter 110a to 111 with a single reference voltage for arc determination, and determine whether or not an arc is occurring by counting the number of times the logical value "1" occurs as a result of the comparison.

[0079] On the other hand, unlike the bandpass filters 110b to 110n and the highpass filter 111, the low-pass filter 110a can be converted from analog to digital by the signal processing unit 210.

[0080] The low-bandwidth signal filtered by the low-pass filter 110a may be digitally converted via an analog-to-digital converter and then supplied to the frequency determination unit 241.

[0081] The signal processing unit 210 performs an FFT analysis on the current value sensed by the current sensor 50 to first detect an estimated signal that is predicted to be an arc signal based on the magnitude and frequency of the pulses in the arc state. It can then determine whether or not an arc is occurring based on the magnitude and frequency of the pulses generated by the device connected to the transmission line 10 (e.g., a power supply or inverter).

[0082] The reason for performing a separate FFT analysis only on the low-pass filter 110a is that 4) the signal processing unit 210, which has a comparison function, may mistakenly identify inverter noise or noise generated from the power supply as an arc, and 5) there is concern that noise generated from loads other than the power supply or inverter may be confused with an arc.

[0083] 6) In addition, depending on the load connected to the transmission line 10, periodic noise with large amplitude may occur, and a structure that simply compares the output value of the low-pass filter 110a with the reference voltage may misinterpret the noise as an arc.

[0084] The arc detection unit 220 may determine whether or not an arc is occurring by performing an FFT analysis on the signal processed by the signal processing unit 210, or by comparing and counting the output values ​​of each filter 110a to 111 with a reference voltage, or by providing multiple reference voltages to each filter 110a to 111 to create DC power quality data for the DC flowing through the line 10. Furthermore, if the arc detection unit 220 determines that an arc is occurring in the line 10, it can switch on the circuit breaker 300 to interrupt the DC flowing through the line 10.

[0085] The arc detection unit 220 determines whether an arc has occurred in the transmission line 10 if all of the comparison results from the signal processing unit 210 are identified as arc detection; if, as a result of the comparison by the signal processing unit 210, the result value determined to be an arc is greater than the result value not determined to be an arc; and if, as a result of the comparison by the signal processing unit 210, the result value determined to be an arc is less than the result value not determined to be an arc, the output value of the low-pass filter 110a is determined to be an arc. The method includes: 10) a method for determining whether an arc has occurred in the transmission line 10, and 11) a method for determining whether an arc has occurred in the transmission line 10, prioritizing the FFT analysis result when the FFT analysis result of the signal processing unit 210 is determined to be an arc and at least one of the output values ​​of filters 110a to 111 is determined to be an arc, and prioritizing the arc determination result of the high-pass filter 111, and determining whether an arc has occurred in the transmission line 10 when at least one arc has occurred in filters 110a to 110n other than the high-pass filter 111.

[0086] Here, item 11) is a method applicable when the arcs generated in the line 10 are mainly high-bandwidth, and item 9) is a method applicable when the arcs generated in the line 10 are mainly low-bandwidth.

[0087] Since the frequency band of the arc may differ depending on the line 10 to which the arc detection device according to the embodiment is connected, and the load connected to the line 10, it is desirable to use one of the items 7) to 11) above that is suitable for the entire electrical system to detect the arc.

[0088] The method according to the embodiment described above can be created as a program for execution on a computer. The program can also be stored on a computer-readable recording medium, and examples of computer-readable recording media include ROM, RAM, CD-ROM, magnetic tape, floppy disk, optical data storage device, etc.

[0089] Computer-readable recording media are distributed across a network of connected computer systems, and computer-readable code is stored and executed in a distributed manner. Functional programs, code, and code segments for realizing the above method can be easily inferred by programmers in the art to which this invention belongs.

[0090] Furthermore, although preferred embodiments of the present invention have been illustrated and described above, the present invention is not limited in any way to the specific embodiments described above, and it goes without saying that various modifications can be made by persons with ordinary skill in the art to which the invention belongs without departing from the gist of the invention claimed in the claims, and such modifications should not be understood individually from the technical idea or prospects of the present invention.

Claims

1. comprising a current sensor, a low-pass filter, a high-pass filter, and one or more band-pass filters, The low-pass filter, the one or more band-pass filters, and the high-pass filter are applied to the frequency band connected to the line where arc generation is expected to occur, thereby dividing the frequency band into multiple detection bands and detecting the arc. The output value of the band-pass filter is compared with the second reference voltage to the nth reference voltage, respectively, to generate power quality evaluation data. The second to the nth reference voltages are set to be different from each other, and are set to be different from the first reference voltage required for arc detection. The frequency bands of the low-pass filter, the one or more band-pass filters, and the high-pass filter each partially overlap with the frequency bands of other filters adjacent to each filter. In the aforementioned multiple detection bands, a specific frequency band where noise caused by a load connected to the line exists is excluded from arc detection. The signal filtered by the low-pass filter is converted into a digital signal, subjected to FFT processing, and then compared with predefined pulse size and frequency conditions for the arc state to detect the arc signal and the predicted estimated signal. The signal filtered by the aforementioned band-pass filter is compared with a reference voltage to generate a first comparison result without converting it to a digital signal or performing FFT processing. Without converting the signal filtered by the aforementioned high-pass filter to a digital signal or performing FFT processing, a second comparison result is generated by comparing it with a reference voltage. Based on the detected estimated signal, the first comparison result, and the second comparison result, it is determined whether or not an arc occurs on the line. Arc detection device equipped with multi-frequency band discrimination function.

2. For each of the aforementioned detection bands, a band detection unit compares the magnitude of the waveform detected through a band-pass filter with a preset arc reference value. A calculation unit that counts the detection results for each detection band and determines that an arc is occurring when the count value deviates from a preset reference count value, An arc detection device equipped with a multi-frequency band discrimination function according to claim 1, characterized in that it is configured to include the following.

3. The aforementioned bandwidth detection unit, Arc detection device equipped with a multi-frequency band discrimination function according to claim 2, characterized by including a combination of two or more of a low-pass filter, a band-pass filter, and a high-pass filter.

4. The aforementioned arithmetic unit, Each signal output from the bandwidth detection unit is compared with a preset first reference voltage, and the comparison result is output as the number of detections. The arc detection device with a multi-frequency band discrimination function according to claim 2, further comprising a signal processing unit for counting the number of detections.

5. The aforementioned arithmetic unit, A signal processing unit that counts arc detection results exceeding a reference value for each detection band, The arc detection device with a multi-frequency band discrimination function according to claim 4, characterized in that it includes an arc determination unit that determines that an arc is occurring when the number of arc detections counted by the signal processing unit exceeds a preset reference number of detections.

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