KR102002606B1 - Arc detecting apparatus of power distribution system and the method thereof - Google Patents

Abstract

 The present invention relates to a current sensor for sensing a first current flowing in a first line of a system in which an influence of noise due to operation is detected in a first frequency band; A first frequency data generator for processing the sensing value for the first current in each of the first time interval and the second time interval to generate first frequency data and second frequency data for the first frequency band; And an arc determination unit for determining an arc occurrence possibility of the system in accordance with first comparison data of the first frequency data and the second frequency data, wherein the first determination unit determines a first load variation time point Wherein the first time period is a time period before the first load change time point and the second time period is a time period after the first load change time point.

Description

TECHNICAL FIELD [0001] The present invention relates to an arc detection apparatus and an arc detection method for a power distribution system. [0002] ARC DETECTING APPARATUS OF POWER DISTRIBUTION SYSTEM AND THE METHOD THEREOF [

The present invention relates to a technique for detecting an arc. Specifically, the present invention relates to a technique for detecting an arc in a power distribution system.

Arc is the flow of current between two electrodes that are either in contact with each other or are incompletely in contact with each other.

Arcs can be largely classified into series arcs that occur in one conductor, parallel arcs that occur between two conductors, ground arcs that occur between one conductor and ground, and cross arcs that occur between other networks.

Such arcing in the distribution system can cause some devices to fail. Particularly, when such an arc is left to be generated continuously, it is necessary to interrupt the distribution system so as to detect an arc at an early stage and prevent further arcing because an electric fire may occur due to deterioration due to an arc discharge .

When an arc occurs, a component of a specific frequency band (for example, several tens of kHz) is generated in the line of the power distribution system, so that it is possible to detect the arc by analyzing the components of this frequency band. However, recent power distribution systems often include power conversion devices using switching devices. In many cases, the switching noise generated during normal operation of the power conversion device is similar to the frequency band due to the arc, so that the switching noise and the arc are distinguished There is a problem that it is difficult. Accordingly, there may arise a problem that the noise of the power converter occurring in a normal operating state may be recognized as an arc.

In recent years, there are many cases in which power distribution systems perform control functions through switching operation in a commercial frequency band (for example, 50 Hz to 60 Hz) or twice the frequency band using a thyristor (SCR) It is necessary to precisely detect whether or not an arc is generated in consideration of the switching operation.

In this context, it is an object of the present invention to provide a technique for detecting an arc.

In another aspect, an object of the present invention is to provide a technique for distinguishing between noise and arc that arises in normal operation.

In another aspect, an object of the present invention is to provide a technique for precisely detecting whether or not an arc is generated, even when there is a low-frequency operation by a thyristor or the like as well as a high-frequency switching operation of the power conversion apparatus.

According to an aspect of the present invention, there is provided a method of operating a semiconductor device including a current sensor for sensing a first current flowing in a first line of a system in which an influence of noise due to operation is detected in a first frequency band; A first frequency data generator for processing the sensing value for the first current in each of the first time interval and the second time interval to generate first frequency data and second frequency data for the first frequency band; And an arc determination unit for determining an arc occurrence possibility of the system in accordance with first comparison data of the first frequency data and the second frequency data, wherein the first determination unit determines a first load variation time point Wherein the first time period is a time period before the first load change time point and the second time period is a time period after the first load change time point.

In the arc detection apparatus, the arc detection device processes the sensing value for the first current in each of a third time interval and a fourth time interval having a longer time interval than the first time interval and the second time interval Further comprising a second frequency data generator for generating third frequency data and fourth frequency data for a second frequency band including a frequency band lower than the first frequency band, And the second comparison data of the fourth frequency data may be further considered to determine the possibility of arcing the system.

In the arc detection device, the third time period and the fourth time period may be 10 times or more times, respectively, between the first time period and the second time period.

In the arc detection device, the third time period is a time period before the first load change time point, and the fourth time period is a time period after the first load change time point based on the first load change time point have.

In the arc detection apparatus, the second frequency band may include a commercial frequency of the power system or a frequency twice the commercial frequency of the power system.

In the arc detection apparatus, when it is determined that there is an arc possibility as a result of analysis of the first comparison data, the second frequency data generation unit generates the third frequency data and the fourth frequency data, It is possible to finally determine whether or not an arc is generated in consideration of the second comparison data.

In the arc detection apparatus, the first frequency data generator may generate the first frequency data and the second frequency data for the first frequency band through a Fourier transform.

In the arc detection apparatus, the second frequency data generator may generate the third frequency data and the fourth frequency data for the second frequency band through a Fourier transform.

The arc detection device comprising: a high-pass filter for passing a high-frequency component with respect to a sensing value for the first current; And a preprocessor for changing a frequency component in the second frequency band with respect to a sensing value passed through the high-pass filter.

In the arc detection apparatus, the pre-processing unit may toggle the first value and the second value alternately at every point where the sensing value crossing the high-pass filter crosses the preprocess reference value while raising or lowering the pre-processing reference value.

According to another aspect of the present invention, there is provided a method of operating a system, comprising: a first step of sensing a first current flowing in a first line of a system in which an influence of noise due to operation is detected in a first frequency band; A second step of processing a sensing value for the first current in each of a first time interval and a second time interval to generate first frequency data and second frequency data for the first frequency band; A third step of determining an arc occurrence possibility of the system according to first comparison data of the first frequency data and the second frequency data; Wherein when it is determined that there is an arcing possibility in the third step, a sensing value for the first current in each of a third time interval and a fourth time interval having a longer time interval than the first time interval and the second time interval, A fourth step of generating third frequency data and fourth frequency data for a second frequency band including a frequency band lower than the first frequency band by processing the fourth frequency data; And a fifth step of secondarily determining an arc occurrence possibility of the system in consideration of second comparison data of the third frequency data and the fourth frequency data.

In the arc detection method, the first time period and the third time period are time periods before the first load change time point based on a first load change time point at which the load amount fluctuates beyond a predetermined size, The fourth time period may be a time period after the first load change time point.

In the arc detection method, the third time period and the fourth time period may be 10 times or more times, respectively, between the first time period and the second time period.

In the arc detection method, the second frequency band may include a frequency of the power system or a frequency twice the frequency of the power system.

In the arc detection method, the first frequency data, the second frequency data, the third frequency data, and the fourth frequency data may be generated through a Fourier transform.

In the arc detection method, a pre-processing step of changing a frequency component in the second frequency band with respect to a sensing value for the first current may be performed before the fourth step.

In the arc detection method, the preprocessing step may be performed in such a manner that the sensing value for the first current is toggled so as to alternate between the first value and the second value at every point where the preprocessing reference value crosses while raising or lowering the reference value .

 As described above, according to the present invention, an arc generated in the power system can be detected and the power system can be stably interrupted based on the detected arc. In addition, according to the present invention, there is an effect that the frequency of arc detection can be reduced by distinguishing noise and arc generated in normal operation. Further, according to the present invention, it is possible to accurately detect whether or not an arc is generated in spite of a low-frequency operation by a thyristor or the like as well as a high-frequency switching operation of the power conversion apparatus.

1 is a configuration diagram of a power system according to an embodiment of the present invention.
2 is a block diagram of an arc detection apparatus 110 according to an embodiment of the present invention.
3 is a diagram showing a first frequency band waveform of a first current when an arc occurs.
4 is a diagram showing a switching noise waveform of the power converter detected at the first current.
5 is a diagram showing a reference frequency waveform and a comparison frequency waveform.
6 is a diagram showing the first time period and the second time period in the waveform of the first current.
FIG. 7 is a chart showing the quantization of the probability similarity by frequency.
8 is a diagram for explaining an example of determining the first time period and the second time period from the inflection point.
9 is a block diagram of an arc detection apparatus further including an edge data generation unit.
10 is a diagram showing an example in which edge detection processing is applied.
11 is a diagram for explaining the differential convolution process.
12 is a flowchart of an arc detection method according to another embodiment of the present invention.
13 is a block diagram of an arc detection apparatus according to another embodiment of the present invention.
14 is a block diagram of an arc detection apparatus according to another embodiment of the present invention.
FIG. 15 illustrates a waveform obtained by filtering a sensed current using a high-pass filter and a current waveform by an arc.
FIG. 16 illustrates a waveform when pre-processing is performed on the sensing current value when no arc is generated.
FIG. 17 illustrates a result of analyzing the second frequency band after pre-processing the sensing current value when no arc is generated.
18 illustrates waveforms when pre-processing is performed on a sensing current value when an arc occurs.
FIG. 19 illustrates a result of analyzing a second frequency band after pre-processing a sensing current value when an arc occurs.
20 is a flowchart of an arc detection method according to another embodiment of the present invention.

Hereinafter, some embodiments of the present invention will be described in detail with reference to exemplary drawings. It should be noted that, in adding reference numerals to the constituent elements of the drawings, the same constituent elements are denoted by the same reference numerals whenever possible, even if they are shown in different drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

In describing the components of the present invention, terms such as first, second, A, B, (a), and (b) may be used. These terms are intended to distinguish the constituent elements from other constituent elements, and the terms do not limit the nature, order or order of the constituent elements. When a component is described as being "connected", "coupled", or "connected" to another component, the component may be directly connected to or connected to the other component, It should be understood that an element may be "connected," "coupled," or "connected."

1 is a configuration diagram of a power system according to an embodiment of the present invention.

Referring to FIG. 1, a power system 100 includes a plurality of devices 110, 120, 130, and 140, and these devices 110, 120, 130, and 140 may be connected by lines. One line 154 is provided between the first device 120 and the second device 130 and another line 152 is provided between the second device 130 and the third device 140 have. For convenience of explanation, the latter is referred to as a first line 152 and the former is referred to as a second line 154. [

Arcs may occur in these lines 152 and 154 of the power system 100. [ In FIG. 1, an arc is generated in the second line 154, but an arc may be generated in another position.

The power system 100 includes an arc detection device 110 for sensing the first current i1 of the first line 152 to detect such an arc and analyzing the sensed value to determine whether the arc is arc.

The arc detecting apparatus 110 can detect an arc generated in the second line 154 by analyzing the first current i1 flowing through the first line 152. [ 1, the first line 152 and the second line 154 are shown at different positions, but the first line 152 and the second line 154 may be the same line. In other words, the arc detection device 110 can detect the arc generated in the first line 152 by analyzing the first current i1 flowing through the first line 152. [

Although not shown in FIG. 1, the arc detecting apparatus 110 analyzes the first current i1 flowing through the first line 152 and outputs the first current i1 to the other line or the first device 120, the second device 130, 3 device 140 can also be detected.

2 is a block diagram of an arc detection apparatus 110 according to an embodiment of the present invention.

2, the arc detection apparatus 110 may include a current sensor 210, a frequency data generation unit 220, an arc determination unit 230, and the like. Although not shown in FIG. 2, the arc detection apparatus 110 may further include an additional configuration according to an embodiment.

The current sensor 210 can sense the current flowing in one line of the power system (100 in Fig. 1). According to the embodiment shown in Fig. 1, the current sensor 210 can sense the first current i1 flowing through the first line 152 shown in Fig.

The frequency data generating unit 220 may digitally process the sensed value of the current sensor 210 to generate frequency data.

The arc determining unit 230 may analyze the frequency data generated by the frequency data generating unit 220 to determine the possibility of arcing of the power system 100 in FIG.

Reference is made to FIGS. 3 to 8 to describe additional embodiments of the frequency data generator 220 and the arc determiner 230.

3 is a diagram showing a first frequency band waveform of a first current when an arc occurs.

Referring to FIG. 3, it can be seen that the waveform 310 of the first current i1 rises in the first frequency band FB1. It has been confirmed by a number of experiments that the waveform of a specific frequency band (the frequency band corresponding to FB1 in Fig. 3) is raised when an arc is generated.

Based on this fact, the frequency data generating unit 220 may generate frequency data including the first frequency band FB1 information for the first current i1. The arc determining unit 230 may analyze the first frequency band FB1 included in the frequency data to determine the possibility of arcing.

For example, the frequency data generator 220 may generate the frequency data to include frequency-dependent size information of the first frequency band FB1 with respect to the first current i1. The arc determining unit 230 may compare the magnitude of the frequency of the first frequency band FB1 included in the frequency data with the first arc reference value 320 to determine the possibility of arcing. Specifically, the arc determining unit 230 compares the magnitude of the frequency of the first frequency band FB1 with the first arc reference value 320, and outputs the frequency band of frequencies larger than the first arc reference value 320 to the first frequency band (FB1) is larger than the first reference ratio, it can be judged that the possibility of arcing is high.

Here, the first arc reference value 320, which serves as a reference for arc determination, may have different values for different frequencies. The first arc reference value 320 may have a different value depending on the setting. For example, depending on the characteristics of the power system 100 including the arc detection device 110, the first arc reference value 320 may have a different value, such that the first arc reference value 320 is measured off-line It can be set differently according to the input of the user.

The power system 100 shown in FIG. 1 may include a power conversion device 130. The switching noise generated in the power conversion device 130 may be applied to the first frequency band FB1 shown in FIG. . ≪ / RTI >

4 is a diagram showing a switching noise waveform of the power converter detected at the first current.

Referring to FIG. 4, the switching frequency fsw of the power inverter 130 corresponds to the first frequency band FB1. Accordingly, the switching noise of the power converter 130 appears in the first frequency band FB1 waveform 410 of the first current i1. The switching noise of the power converter 130 may vary depending on the load. In a specific load condition, the first frequency band FB1 of the first current i1 due to the influence of the switching noise 410 may exceed the first arc reference value 320.

Accordingly, when the arc determining unit 230 compares the first arc reference value 320 with the first frequency band FB1 waveform 410 of the first current i1 to determine the possibility of arcing, In case of not operating (normal operating condition), it can be detected that an arc has occurred.

In order to solve the problem of false detection, the frequency data generator 220 may generate a variable value without fixing the first arc reference value 320, which is a reference of comparison, to one value. For example, the frequency data generating unit 220 may generate frequency data based on data measured in a normal operating state of the power system 100, and may generate the frequency data as reference frequency data. The reference frequency data is a substitute for the first arc reference value 320. The arc determination unit 230 may compare the reference frequency data with the comparison frequency data generated at each time point to determine the possibility of arcing.

More specifically, the reference frequency data generated by the frequency data generation unit 220 may include switching noise generated in a normal operating state. The arc determination unit 230 can solve the problem of the arc error due to the influence of the switching noise by comparing the reference frequency data with the comparison frequency data generated at each time point.

5 is a diagram showing a reference frequency waveform and a comparison frequency waveform.

Referring to FIG. 5, reference frequency waveform 510 and comparison frequency waveform 520 are shown. The reference frequency waveform 510 is a first frequency band FB1 waveform of the first current i1 measured in the normal operating state of the power system 100 and the comparison frequency waveform 520 is a waveform 1 < / RTI > current i1.

The arc determination unit 230 includes reference frequency data including the reference frequency waveform 510 and comparison frequency waveform 520 information measured at each point in time It is possible to determine the possibility of arcing irrespective of the influence of the switching noise.

In the foregoing description, it has been described that the switching noise may affect the first frequency band FB1 when the switching frequency fsw of the power conversion apparatus 130 is located in the first frequency band FB1. However, The harmonics of the frequency fsw may correspond to the first frequency band FB1.

In addition to the switching noise of the power conversion device 130, the power system 100 may have other sources of noise sources, such that noise from the noise source sources also affects the first frequency band FB1, It can cause the same problem.

The switching noise of the power inverter 130 may vary in size depending on the load. For example, when the conduction noise is largely generated in the power conversion apparatus 130, the switching noise can be reduced when the load is reduced. Accordingly, when the load is reduced, the influence of the switching noise detected in the first frequency band FB1 can also be reduced.

On the other hand, the frequency data generator 220 generates reference frequency data using the first current i1 sensed in the first time period, and generates the reference frequency data using the first current i1 sensed in the second time period, Data can be generated. The arc determining unit 230 may determine the possibility of arcing of the power system 100 according to the comparison data of the reference frequency data and the comparison frequency data.

6 is a diagram showing the first time period and the second time period in the waveform of the first current with respect to time.

When an arc occurs in the power system 100, a constant inflection point may occur in the current waveform. The arc detection apparatus 110 can distinguish the first time interval TI1 and the second time interval TI2 based on the inflection point.

Referring to Fig. 6, an inflection point occurs at the first point P1 in the waveform of the first current i1. Accordingly, the arc detecting apparatus 110 can set the first time interval TI1 in the section before the inflection point P1 and the second time interval TI2 in the section after the inflection point P1. The end point of the first time period TI1 or the start point of the second time period TI2 may be located within a predetermined time from the point of time when the inflection point P1 appears. Such an inflection point may be caused by the occurrence of an arc, but may occur as the load is reduced or increased to a certain size or more.

On the other hand, the frequency data generating unit 220 can generate the first frequency data in the first time period TI1, and the first frequency data can be used as the above-described reference frequency data. The frequency data generating unit 220 may generate the second frequency data in the second time period TI2, and the second frequency data may be used as the above-described comparison frequency data.

The first time interval TI1 may be further divided into detailed time periods. Referring to FIG. 6, the first time interval TI1 is a time interval between the first time period TI11, the first time period TI12, the first time period TI13, (TI14) and the 1-5th time zone (TI15). The frequency data generator 220 may generate the sub data of the first frequency data in these subdivided time periods. For example, the frequency data generation unit 220 may generate the first sub data of the first frequency data in the first-time interval TI11. In the same manner, the frequency data generation unit 220 may also generate the 1-2 th to the 1-5 th sub data. The frequency data generation unit 220 may generate the first frequency data using the 1-1 to 1-5 sub data. When frequency data is generated by using such sub data, the frequency data generator 220 may generate probability distribution data such as a variance of frequency-dependent magnitudes as well as an average of frequency-dependent magnitudes.

The arc determining unit 230 may determine the possibility of arcing according to the comparison data of the first frequency data and the second frequency data, and the comparison data may indicate the probability similarity with respect to the first frequency data of the second frequency data. Lt; / RTI >

For example, the first frequency data and the second frequency data may include frequency-specific magnitudes, and the first frequency data may include a mean, variance, and standard deviation of the frequency-dependent magnitudes using the time- And the like. Accordingly, the arc determining unit 230 can check whether the frequency of the second frequency data is within the standard deviation of N (N is a positive real number) times the average of the frequency-dependent sizes of the first frequency data , The probability similarity can be calculated according to the N value. The arc determination unit 230 may generate the comparison data by calculating the probability similarity for each frequency. If the degree of similarity is high and the probability of occurrence of arc is low and the degree of similarity is low, it can be judged that the possibility of arcing is high.

More specifically, the arc determination unit 230 may generate comparison data by quantizing the probability similarities between the first frequency data and the second frequency data for each frequency. For example, the arc determination unit 230 determines whether the frequency-dependent size of the second frequency data falls within the standard deviation range of N (N is a positive real number) times the average of the frequency-dependent sizes of the first frequency data by 1 Or 0 to generate comparison data. Here, N may be a fixed value.

FIG. 7 is a chart showing the quantization of the probability similarity by frequency.

Referring to FIG. 7, the arc determination unit 230 divides the first frequency band FB1 into frequency intervals (1 KHz) of a predetermined size, compares the first frequency data with the second frequency data for each frequency, Whether or not the frequency-dependent size of the data corresponds to the N-fold standard deviation of the frequency-dependent size of the first frequency data can be expressed as a probability similarity of 1 or 0.

Here, the frequency-dependent magnitude can represent the magnitude of each frequency by the Fourier-transformed value. For example, the frequency data generating unit 220 generates first frequency data and second frequency data according to digital processing including Fourier transform, wherein the frequency-dependent magnitudes included in the first frequency data and the second frequency data are May be a frequency-dependent magnitude obtained by Fourier transforming the sensing value of the first current i1.

7, the arc determination unit 230 generates comparison data and calculates the sum of the probabilistic similarities. If the sum of the probabilistic similarities exceeds the first reference value or exceeds the first reference value, Lt; RTI ID = 0.0 > arc < / RTI > If the first arc variable is equal to or greater than the second reference value or exceeds the second reference value, the arc determining unit 230 may determine that an arc has occurred in the power system 100. [

In order to increase the first arc parameter, the arc determination unit 230 repeats the process of generating the comparison data of the first frequency data and the second frequency data. 6, the frequency data generation unit 220 generates sub data by subdividing the second time period TI2, and the arc determination unit 230 generates comparison data for each of the sub data Can be generated to determine the possibility of arcing. For example, referring again to FIG. 6, the second time period TI2 is subdivided into the second-first time period TI21 and the second-second time period TI22. The frequency data generator 220 may generate frequency-specific size data for the first frequency band FB1 in the 2-1th time interval TI21 and the 2-2 hour time interval TI22, respectively. The arc determining unit 230 then outputs frequency-dependent magnitude data for the first frequency band FB1 generated in the second-time period TI21 and the second-time period TI22 to the first frequency data FB1, The comparison data can be generated.

On the other hand, there may be various embodiments for determining the start time and the end time of the first time interval TI1 and the second time interval TI2.

8 is a diagram for explaining an example of determining the first time period and the second time period from the inflection point.

Referring to FIG. 8, the end point t3 of the first time period TI1 may be located a certain time before the point of time t1 when the inflection point P1 appears. The start time t2 of the second time period TI2 may be located after a certain time from the time point t1 when the inflection point P1 appears.

Although not shown in FIG. 8, the start time of the first time slot TI1 may be equal to the normal operating start time of the power system 100. [

On the other hand, the first time interval TI1 may not be constituted by a continuous time period but may be composed of a combination of several time points. For example, if it is determined that an arc has not occurred at the end of the second time period TI2, the first time period TI1 may be restarted from the end time point of the second time period TI2 or after a certain time from the end time point You can extend it. Since the first time interval TI1 can correspond to the time periods normally operated by the power system 100, all the time periods other than the second time period TI2, except for the time periods to be excluded, May be included in the liver TI1.

On the other hand, in order to distinguish the first time period TI1 from the second time period TI2, it is important to set an inflection point P1 that distinguishes between the first time period TI1 and the second time period TI2. An embodiment for setting such an inflection point P1 will be further described.

9 is a block diagram of an arc detection apparatus further including an edge data generation unit.

9, the arc detection apparatus 910 includes an arc detection unit 210, a frequency data generation unit 220, and an arc determination unit 230, which are included in the arc detection apparatus 110 described with reference to FIG. And may further include a data generation unit 940.

The edge data generation unit 940 generates digital current data by digitizing the sensed value for the first current i1 and generates current edge data through edge detection processing on the digital current data have. The first time period TI1 and the second time period TI2 described above can be determined according to such current edge data.

The edge detection process is a process of finding a discontinuity point of a specific value. The edge detection process is a process of finding a discontinuity at specific values representing successive data under normal circumstances.

10 is a diagram showing an example in which edge detection processing is applied.

An image 1010 on the left side in FIG. 10 is an image obtained by a video device such as a camera. Since the objects (clouds, sky, trees, and mountains) shown in the image 1010 each have a continuous surface, the image data of the inner surface of each object has a continuous or relatively similar data value. On the other hand, each object has different image data, so that a discontinuity point of the image data appears at the boundary of each object. This discontinuity point is an image 1020 on the right side of FIG. When the discontinuity point of the specific image 1010 is displayed in this manner, it is possible to acquire the image 1020 in which only the boundary is displayed as shown in the right image 1020 in FIG.

On the other hand, when an arc is generated in the power system 100, a discontinuity point as described above appears in the current measurement value. The arc detection apparatus 910 according to the embodiment of the present invention can recognize such a discontinuity point and distinguish the first time interval TI1 and the second time interval TI2 before and after the discontinuity point.

The edge detection processing may use a Laplacian filter processing for differentiating data, and a difference convolution processing for calculating a difference of data may be used.

11 is a diagram for explaining the differential convolution process.

Referring to FIG. 11, the time-dependent measurements of the first current i1 may be stored in the first array 1110. In FIG. 11, the first graph 1112 shown on the right side of the first array 1110 is a graph in which the first array 1110 is represented by a time axis and a size axis. Referring to the first graph 1112, it can be seen that the first current i1 varies discontinuously or largely at the inflection point P2.

11, the second arrangement 1120 is an arrangement in which differential convolution is performed by multiplying three consecutive values in the first array 1110 by {-1, 0, 1}. As can be seen from the second arrangement 1120, the data of the specific portion (the fourth data in the second array) is higher than the data of the other portions, which can be the inflection point P2. In FIG. 11, the second graph 1122 shown on the right side of the second array 1120 is a graph showing the second array 1120 in terms of time and magnitude axes. Referring to the second graph 1120, it is confirmed that the inflection point P2 at the first current i1 occurs at time t4.

The values of the first array 1110 described with reference to FIG. 11 are examples of the digital current data described above, and the second array 1120 may be an example of current edge data.

The frequency data generation unit 220 may determine the change time point by comparing the current edge data with the first edge reference value and determine the first time period TI1 and the second time period TI2 based on the change time point .

11, the frequency data generator 220 compares the current edge data stored in the second array 1120 with a first edge reference value (a value corresponding to 1130 in FIG. 11) If it is larger than the edge reference value (the value corresponding to 1130 in FIG. 11), the time corresponding to the current edge data can be determined as the change time point t4.

On the other hand, the frequency data generation unit 220 may determine the change time point using only the negative (-) value of the current edge data, or may determine the change time point using only the positive (+) value. For example, if the frequency data generation unit 220 only recognizes the change time point in a situation where the first current i1 is sharply reduced, the change time point can be determined using only the negative value, and the first current i1 ), The change point may be determined using only a positive value if the change point is to be recognized.

In the case of a parallel arc, the current rapidly increases. Therefore, a positive (+) value of the current edge data is used, May be used to determine the point of change.

Meanwhile, the frequency data generator 220 generates a first edge reference value according to the average and standard deviation of the current edge data when determining the variation time point using the current edge data. Based on the first edge reference value, You can decide. At this time, when the frequency data generation unit 220 determines the change time point only by using a negative value, the current edge data of the current edge data obtained in the specific time period (the third time interval) The mean and standard deviation can be calculated using only data. Here, the first edge reference value can be determined by adding the standard deviation of M (M is a real number) times to the previously calculated average. On the other hand, the frequency data generation unit 220 may determine the variation time point or generate the first edge reference value based on the absolute value of the current edge data.

The mean and standard deviation of the current edge data can be continuously updated, e.g., the average and standard deviation are updated according to the current edge data where the absolute value of the current edge data is less than or equal to the first edge reference value .

Since the edge detection process may be sensitive to the noise of the data, the edge data generation unit 940 may generate the edge current data by using the Gaussian convolution such as Gaussian convolution in the process of digitizing the sensing value for the first current i1. Filter processing can be applied.

12 is a flowchart of an arc detection method according to another embodiment of the present invention.

The arc detection method of FIG. 12 can be performed by the above-described arc detection device, but is not limited thereto and may be performed by other types of hardware.

Referring to FIG. 12, a sensing value of a current flowing in a line, such as the example of the first line 152 in FIG. 1, is digitally converted to generate digital current data (S1202).

Current edge data is generated by the edge detection processing on the digital current data (S1204).

The current edge data is compared with the first edge reference value (S1206). If the current edge data is smaller than the first edge reference value, the digital current data is stored in the first buffer (S1208). The digital current data stored in the first buffer is subjected to Fourier transform processing to generate first frequency data (S1210). Thereafter, the digital current data generation step (S1202) is repeated. The fact that the current edge data is smaller than the first edge reference value means that there is no abrupt change of the current, so that the first frequency data is generated by being classified into the normal operation state. Through this process, the first frequency data can be generated several times. In this case, the first frequency data can be processed by a statistical method and used as reference data for a normal situation.

If the current edge data is equal to or greater than the first edge reference value or exceeds the first edge reference value, the digital current data is stored in the second buffer (S1212), and the digital current data stored in the second buffer The second frequency data is generated through the Fourier transform processing (S1214). The second frequency data is compared with the first frequency data to determine the possibility of arcing (S1216).

On the other hand, in the step of generating the current edge data (S1204), after the Gaussian filter processing is performed on the digital current data, the current edge data is stored in the third buffer, Data can be generated.

Here, the third buffer may be a first in first out (FIFO) buffer in which three pieces of digital current data are stored. In the step of generating current edge data (S1204), current edge data may be generated by multiplying a third buffer storing three digital current data by a differential convolution vector.

The first buffer and the second buffer may also be first in first out (FIFO) buffers.

The arc detecting apparatus described above has been based on a method of judging that an arc is generated when there is a sudden change in current and a component in a high frequency band is increased through various embodiments. Here, the high-frequency band capable of detecting the arc generation is a range similar to the frequency at which the switching noise of the power conversion apparatus occurs, and may range usually from several kHz to several tens of kHz.

This method of determining the arc in accordance with whether there is a sudden change in current using current edge data in addition to the high frequency component has the advantage that the arc occurrence can be detected more accurately even in the presence of the switching noise of the power converter have.

In recent years, the power distribution system has been developed not only in the high frequency switching operation in the range of several kHz to several hundred kHz using the high speed switching device such as MOSFET, IGBT, etc., but also the low frequency switching device such as the thyristor (SCR) To 60 Hz) or twice the frequency of the power supply. In this case, sudden change of current and noise may occur due to the operation of the thyristor or the like. In the case of the arc detecting apparatus of the above-described embodiment, a sudden change in current due to a normal low frequency switching operation or the like and switching noise may be erroneously detected as an arc. Hereinafter, another embodiment will be described in which erroneous detection of an arc occurrence can be reduced even in the presence of a low frequency switching operation. In the embodiments described below with reference to Figs. 13 to 20, the above-described contents, particularly the setting of the arc reference value described in Figs. 3 to 12, the setting between the current inflection point and the time point, and the generation of edge data The related contents can be utilized in the same or similar manner.

13 is a block diagram of an arc detection apparatus according to another embodiment of the present invention. 13, the arc detection apparatus 1300 includes a current sensor 1310, a first frequency data generation unit 1320, an arc determination unit 1330, an edge data generation unit 1340, A high-pass filter 1350 and a high-pass filter 1360, and the like.

The current sensor 1310 can sense the current flowing in one line of the power system. The current sensor 1310 can sense the first current i1 flowing through the line 152 illustrated in Fig.

The first frequency data generator 1320 may digitally process the sensed value of the current sensor 1310 to generate frequency data. The first frequency data generator 1320 processes the sensing value for the first current in the first time interval to generate the first frequency data for the first frequency band, Value to generate second frequency data for the first frequency band. The first frequency data generator 1320 may generate the first frequency data and the second frequency data for the first frequency band through the Fourier transform process. As described above, the first time period and the second time period are based on the first load change time point at which the load fluctuates beyond a predetermined size, the first time period is a time period before the first load change time point, The time period may be a time period after the first load change time point.

The second frequency data generator 1350 may digitally process the sensed value of the current sensor 1310 to generate frequency data. The second frequency data generator 1350 processes the sensing value for the first current in the third time interval to generate third frequency data for the second frequency band, Value to generate fourth frequency data for the second frequency band. The second frequency data generator 1350 may generate the third frequency data and the fourth frequency data for the second frequency band through the Fourier transform process.

As in the first and second time periods, the third time period and the fourth time period are based on the first load change time point at which the load changes over a certain size, and the third time period is before the first load change time point And the fourth time zone may be a time zone after the first load change time point. The third time interval before the first load variation time point is for obtaining reference data in normal operation and the fourth time interval after the first load variation time point can be utilized as comparison data for arc occurrence judgment.

Here, the third time interval and the fourth time interval may be intervals having longer time periods than the first time interval and the second time interval, respectively. Considering that the first time interval and the second time interval are for detecting a frequency component in the range of, for example, several kHz to several tens of kHz, and the third time interval and the fourth time interval are for detecting the components of the commercial frequency band, The 3-hour and 4-hour periods are preferably 10 times or more times longer than the 1-hour and 2-hour periods. For example, the first time interval and the second time interval may be 2 ms, and the third time interval and the fourth time interval may be 20 ms.

The second frequency band includes a lower frequency range than the first frequency band, and the second frequency band may range from 50 Hz to 60 Hz, which is a commercial frequency of the power system, or may be a range including a commercial frequency and its harmonics . That is, the first frequency data generator 1320 analyzes the high frequency band of the first current and the second frequency data generator 1350 analyzes the low frequency band including the commercial frequency of the first current. To this end, the first frequency data generator 1320 samples and analyzes relatively short time periods (the first time interval and the second time interval), and the second frequency data generation unit 1350 samples and analyzes the relatively short time periods (Between the third time interval and the fourth time interval) longer than that of the second time interval 1320 can be sampled and analyzed. The second frequency data generator 1350 may analyze the low frequency band including the commercial frequency and determine that it is a normal switching operation by the thyristor when the commercial frequency and its harmonic components are analyzed to be high.

On the other hand, the second frequency data generator 1350 analyzes the low frequency band including the commercial frequency band. However, the second frequency data generator 1350 may analyze not only the low frequency band but also the high frequency band. The second frequency data generation unit 1350 samples a relatively long time interval and analyzes the high frequency band. The first frequency data generation unit 1320 samples a relatively short time interval and analyzes the high frequency band. And can be utilized to improve the accuracy of arc detection. When the first frequency data generator 1320 samples a relatively short time interval and analyzes frequency components, the first frequency data generator 1320 tends to show an increase in its size in the entire frequency band than the actual frequency band. As a result, There is a possibility that a problem of erroneously detecting that an arc has occurred may occur. The second frequency data generation unit 1350 samples a relatively long time interval and analyzes the high frequency band. The first frequency data generation unit 1320 samples a relatively short time interval and analyzes the high frequency band. The possibility of erroneous detection can be reduced.

The arc determination unit 1330 may analyze the frequency data generated by the first frequency data generation unit 1320 and the second frequency data generation unit 1350 to determine the arc generation possibility of the system. The arc determination unit 1330 samples the relatively short time interval and samples the comparison data of the first frequency data and the second frequency data as a result of analyzing the high frequency band and a relatively long time interval to generate a low frequency band and / It is possible to determine the possibility of arcing by considering the comparison data of the third frequency data and the fourth frequency data which are the result of analyzing the high frequency band together. By analyzing the low frequency band using the comparison data of the third frequency data and the fourth frequency data, it is examined whether or not there is a change in the low frequency band, thereby reducing the possibility of erroneously judging the normal low frequency switching operation by the thyristor, etc. . For example, if the current detected in the normal operation state is analyzed for the high frequency band in the first frequency data generation unit 1320, the high frequency component can be detected due to the waveform of the pulse shape generated by the switching operation of the thyristor or the like Therefore, it can be judged that there is an arc possibility in the first place. In this case, if the second frequency data generator 1350 analyzes the low frequency band and the commercial frequency and its harmonic components are remarkably revealed compared to other frequency components, the second frequency data generator 1350 determines normal operation by the thyristor or the like, have. When the second frequency data generator 1350 analyzes the high frequency band using the comparison data of the third frequency data and the fourth frequency data, sampling is performed in a relatively short time interval (between the first time interval and the second time interval) There is an advantage that the change in the high frequency band can be more accurately determined by supplementing the result of analyzing the high frequency band with one data (the first frequency data and the second frequency data).

Alternatively, the first frequency data generator 1320 and the second frequency data generator 1350 may operate simultaneously. However, unlike the first frequency data generator 1320 and the second frequency data generator 1350, The second frequency data generator 1350 may be operated to compare the third frequency data and the fourth frequency data to determine whether an arc is finally generated. In this case, when the load fluctuates more than a predetermined magnitude and the high frequency bands are compared using the first frequency data and the second frequency data, the third frequency data and the fourth frequency data are generated only when the arc probability is predicted, It is preferable because it is possible to reduce the number of analysis times and time for a relatively long time interval (the third time interval and the fourth time interval), and reduce the consumption of hardware resources.

The arc detection apparatus 1300 may include an edge data generation unit 1340 as a method for determining whether there is a sudden change in current. The edge data generation unit 1340 can be used to determine whether the current is abruptly changed in the manner described above.

The arc detection apparatus 1300 may include a high-pass filter 1360 (HPF) to perform filtering on the sensed current and generate the first frequency data and the second frequency data using the filtered current values . When the magnitude of the current in a normal situation is much larger than the amount of change in the current due to the arc generation, when the frequency components are analyzed by the first frequency data generation unit and the second frequency data generation unit by a method such as Fourier transform, The current component may not be detected effectively. The high-pass filter 1360 can be selectively used to enable the current component due to arc generation to be efficiently detected in this situation.

As described above, the arc detection apparatus 1300 analyzes the components of the low frequency band (which can selectively include a high frequency band) generated by the second frequency data generation unit 1350 and uses it for arc determination, And a case where the arc is erroneously determined to have arisen despite the arc not being caused by the noise can be reduced.

On the other hand, the arc detection apparatus 1300 illustrated in FIG. 13 can be used in a power system including a power conversion apparatus that converts and supplies power, and in particular, in a power distribution system to detect whether or not an arc is generated. The present invention can include a power system or an electrical distribution system including an arc detection device as well as an arc detection device.

14 is a block diagram of an arc detection apparatus according to another embodiment of the present invention. The arc detecting apparatus 1400 shown in FIG. 14 differs from the arc detecting apparatus 1300 shown in FIG. 13 in that it further includes a preprocessing section 1470. The preprocessor 1470 can be added to allow the second frequency data generator 1360 to more accurately distinguish whether the second frequency band component is due to operation of a thyristor or the like. Hereinafter, the operation of the preprocessor 1470 will be described in detail.

First, the reason why the forwarding unit 1470 is necessary will be described with reference to FIG. 15A shows a sensing current waveform 1510, FIG. 15B shows a filtered current waveform 1530 after a sensing current waveform 1510 passes through a high-pass filter, FIG. 15C shows an arc generated when an arc occurs, The current waveforms 1550 and (d) illustrate the synthesized current waveform 1570 which is a combination of the filtered current waveform 1530 and the arc current waveform 1550.

The sensing current waveform 1510 may be a waveform having a frequency of a commercial frequency or a frequency component thereof twice or more by a low-frequency switching operation such as a thyristor. For example, when a thyristor or the like operates as a phase control rectifier to perform a dimming function, a current waveform in which a part of the phase of a commercial frequency is cut off can be sensed as shown in FIG. 15 (a). When the sensing current waveform 1510 passes through the high-pass filter HPF, a waveform in which a pulse is generated in a portion where the sensing current waveform 1510 is abruptly changed as in the filtered current waveform 1530 in Fig. 15 (b) Lt; / RTI > FIG. 15 (c) illustrates the arc current waveform 1550, and FIG. 15 (d) illustrates the combined current waveform 1570 of the filtered current waveform 1530 and the arc current waveform 1550. That is, FIG. 15B shows a waveform to be subjected to frequency analysis in a normal operation state, and FIG. 15D shows a waveform to be analyzed when an arc occurs.

When the first frequency data generator 1530 analyzes the filtered current waveform 1530, which is a frequency analysis target waveform in a normal operation state, not only a sudden change in current occurs but also a high frequency component is detected due to a pulse waveform It can be judged that there is an arc possibility in the first place. In this case, if a relatively long section is sampled with respect to the current waveform 1530 filtered by the second frequency data generation section and analysis is performed on the low frequency band, if the commercial frequency and its harmonic component are significantly exposed to other frequency components, It is possible to prevent the detection of an arc fault.

However, since the filtered current waveform 1530 is in the form of a pulse as illustrated in FIG. 15 (b), it may have a component of a commercial frequency band but may not be large in size. In this case, even if the low frequency band of the current waveform 1530 filtered by the second frequency data generation unit is analyzed, the commercial frequency and its harmonic components are not clearly revealed, and it is difficult to accurately determine whether the current frequency is due to the normal operation by the thyristor Lt; / RTI > That is, the second frequency data generator generates a waveform 1530 in the normal situation illustrated in FIG. 15 (b) and a synthesized current waveform 1570 in which the arc illustrated in FIG. 15 (d) If the filtered current waveform 1530 has a small pulse width, the commercial frequency and its harmonic components are not so large, and it may be difficult to distinguish the components. This phenomenon may be more problematic as the pulse width of the filtered current waveform 1530 is smaller as the commercial frequency and the harmonic component thereof become smaller.

The preprocessor 1470 in FIG. 14 is for enabling the filtered current waveform 1530 in the case where an arc is not generated and the synthesized current waveform 1570 in the case where an arc occurs in such a situation to be distinguishable in a low frequency band, 15 (b), the waveform of the pulse-shaped signal generated periodically at the commercial frequency, such as the filtered current waveform 1530 illustrated in FIG. 15 (b) ), It is possible to perform a function of detecting a relatively small frequency component of the commercial frequency. Hereinafter, the operation of the preprocessing unit will be described with reference to FIGS. 16 and 17. FIG.

FIG. 16 illustrates a waveform when pre-processing is performed on the sensing current value when no arc is generated. 16 (a) illustrates a sensing current waveform 1510, FIG. 16 (b) illustrates a filtered current waveform 1530, and FIG. 16 (c) illustrates a waveform 1630 after preprocessing, . Reference numeral 1620 in FIG. 16 (b) illustrates a pre-processing reference value.

The preprocessing unit compares the filtered current waveform 1530 with the preprocessing reference value 1620 and outputs a first value (e.g., '0') each time the filtered current waveform 1530 crosses the preprocessing reference value 1620, ) And a value of a second value (for example, '1') alternately. That is, if the filtered current waveform 1530 crosses the pre-processing reference value 1620 while the pre-processed waveform 1630 has a value of '0', the preprocessed waveform 1630 is changed to '1' When the filtered current waveform 1530 crosses the preprocess reference value 1620, the preprocessed waveform 1630 is changed to '0'. Here, the filtered current waveform 1530 is shown toggling when crossing while rising the preprocessing reference value 1620, but conversely, it may be toggled each time the crossing is performed while descending. The preprocessed waveform 1630 illustrated in Fig. 16 (c) can then be generated. In the case of the pre-processed waveform 1630, the frequency component is the same as the filtered current waveform 1530, but is not in the form of a pulse, so that the frequency component of the commercial frequency can be significantly displayed compared to the filtered current waveform 1530. Analysis of the components of the low frequency band with respect to the waveform 1630 after the preprocessing clearly reveals the commercial frequency and its harmonic components as shown in FIG.

18 illustrates waveforms when pre-processing is performed on a sensing current value when an arc occurs. 18 (a) illustrates a sensing current waveform, FIG. 18 (b) illustrates a filtered current waveform 1870, and FIG. 18 (c) illustrates a pre-processing waveform 1830 after pre- . The sensing current waveform includes a current waveform 1810 by a thyristor or the like and a current waveform 1850 by an arc. Reference numeral 1820 denotes a pre-processing reference value.

The preprocessing unit compares the filtered current waveform 1870 with the preprocessing reference value 1820 so that the filtered sensing current waveform alternates between '0' and '1' each time it crosses the preprocessing reference value 1820 Toggle. Then, a pre-processed waveform 1830 of Fig. 18 (c) can be generated. In the case of the pre-processed waveform 1830 illustrated in FIG. 18 (c), the current component due to the thyristor or the like is also toggled, but the component due to the arc also becomes a toggle so that the commercial frequency and its harmonic components are relatively reduced, The component is relatively increased. Analysis of the components of the low frequency band with respect to the preprocessed waveform 1830 illustrated in FIG. 18 (c) shows that the frequency of the commercial frequency (for example, 60 Hz) It can be seen that they appear mixed.

17 and 19, the pre-processor changes the frequency component of the filtered current waveform. For the pulse waveform of the commercial frequency occurring in the normal operating condition, In case of arcing, it is possible to distinguish between the normal operation and the arc generation by analyzing whether the commercial frequency component and the harmonic component thereof are remarkably revealed compared with the other frequency components.

20 is a flowchart of an arc detection method according to another embodiment of the present invention. The arc detection method of FIG. 20 can be performed by the above-described arc detection device, but is not limited thereto, and may be performed by other types of hardware.

Referring to FIG. 20, it is possible to detect a current flowing in a line like the example of the first line 152 of FIG. 1 (S2002). The detected current can be digitally converted and processed in the form of digital current data.

Next, it can be determined whether or not the detected current involves a sudden change (S2004). The abrupt change of the current can be performed in such a manner that the current edge data is generated by the edge detection process as described above, and the current edge data is compared with the edge reference value.

If it is determined in step S2004 that there is a sudden change in the current, the process proceeds to step S2006, and if it is determined that there is no abrupt change in the current, the process may return to step S2002.

If it is determined in step S2004 that there is a sudden change in the current, the first frequency data and the second frequency data may be generated and compared (S2006). The first frequency data and the second frequency data may be data obtained by analyzing the first frequency band which is a relatively high frequency band by sampling the first time interval and the second time interval described above.

Next, based on the comparison result between the first frequency data and the second frequency data, the arc probability can be determined first (S2008). The method of determining the arc probability by using the first frequency data and the second frequency data has been described above, so that a duplicate explanation will be omitted.

If it is determined in step S2008 that the arc possibility is low or not, the process may return to step S2002 and return to the next current detection step. Through this process, the first frequency data acquired many times can be accumulated and statistically processed and used as reference data in a normal operation situation.

If it is determined in step S2008 that there is an arc possibility as a result of the first determination on the arc possibility, the third frequency data and the fourth frequency data may be generated and compared (S2012) through a preprocessing process on the current data (S2010).

The preprocessing of the current data performed in step S2010 may be performed by toggling the values of '0' and '1' alternately at every point where the current crosses the preprocessing reference value as described above.

The third frequency data and the fourth frequency data may be data obtained by analyzing a second frequency band including a relatively low frequency range by sampling the third time interval and the fourth time interval which are relatively long time periods as described above. The third frequency data and the fourth frequency data may be data for a low frequency band including a commercial frequency or a double frequency thereof as described above, or data including both a low frequency band and a high frequency band. The third time zone and the fourth time zone are based on the first load change time point at which the load changes over a predetermined size, the third time zone is before the first load change time, the fourth time zone is the first load change time And may be a section after the time point. The third and fourth time zones may be at least 10 times greater than the first and second zones, respectively.

Next, whether or not an arc is generated can be finally determined by integrating the abrupt change in the current, the comparison result between the first frequency data and the second frequency data, and the comparison result between the third frequency data and the fourth frequency data (S2014) . If it is determined that the arc is not generated finally, the third frequency data may be accumulated and statistically processed and utilized as reference data in a normal operation state.

Analysis of the third frequency data and the fourth frequency data with respect to the third time interval and the fourth time interval, which are relatively long time intervals each time a sudden change in the current is detected, consumes a lot of time for analyzing the data, The first frequency data and the second frequency data between the first time interval and the second time interval which are relatively short time periods and the abrupt change of the current and the second frequency data as shown in Fig. 20 are analyzed first, and as a result, Analyzing the third frequency data and the fourth frequency data only when the probability of occurrence is predicted reduces consumption of unnecessary hardware resources and data analysis time while reducing erroneous detection and accurate detection of arc occurrence.

As described above, according to the present invention, an arc generated in the power system can be detected and the power system can be stably interrupted based on the detected arc. In addition, according to the present invention, there is an effect that the frequency of arc detection can be reduced by distinguishing noise and arc generated in normal operation. According to the present invention, not only the switching noise in the high frequency band but also the operation of the thyristor in the low frequency band and the arc occurrence are distinguished from each other, thereby improving the accuracy of the arc detection.

It is to be understood that the terms "comprises", "comprising", or "having" as used in the foregoing description mean that the constituent element can be implanted unless specifically stated to the contrary, But should be construed as further including other elements. All terms, including technical and scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs, unless otherwise defined. Commonly used terms, such as predefined terms, should be interpreted to be consistent with the contextual meanings of the related art, and are not to be construed as ideal or overly formal, unless expressly defined to the contrary.

The foregoing description is merely illustrative of the technical idea of the present invention, and various changes and modifications may be made by those skilled in the art without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are intended to illustrate rather than limit the scope of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention should be construed according to the following claims, and all technical ideas within the scope of equivalents should be construed as falling within the scope of the present invention.

Claims (17)

A current sensor for sensing a first current flowing in a first line of the system in which the influence of noise due to the operation is detected in a first frequency band including a switching frequency of the power inverter;
A first frequency data generator for processing the sensing value for the first current in each of the first time interval and the second time interval to generate first frequency data and second frequency data for the first frequency band;
An arc determination unit for determining an arc occurrence possibility of the system according to first comparison data of the first frequency data and the second frequency data; And
Processing a sensed value for the first current in each of a third time interval and a fourth time interval having a longer time interval than the first time interval and the second time interval to include a frequency band lower than the first frequency band And a second frequency data generator for generating third frequency data and fourth frequency data for the second frequency band,
The first time period is a time period before the first load change time point and the second time period is a time period after the first load change time point based on a first load change time point at which the load changes to a predetermined size or more ,
Wherein the arc determining unit determines an arc occurrence possibility of the system by further considering second comparison data of the third frequency data and the fourth frequency data. delete The method according to claim 1,
Wherein the third time period and the fourth time period are respectively 10 times or more times longer than the first time period and the second time period. The method of claim 3,
Wherein the third time period is a time period before the first load change time point and the fourth time period is a time period after the first load change time point based on the first load change time point. The method according to claim 1,
Wherein the second frequency band comprises a commercial frequency of the power system or a frequency twice the commercial frequency of the power system. The method according to claim 1,
Wherein the second frequency data generator generates the third frequency data and the fourth frequency data when it is determined that there is an arc possibility as a result of the analysis of the first comparison data, And an arc determination unit for determining whether or not an arc is generated. The method according to claim 1,
Wherein the first frequency data generator generates the first frequency data and the second frequency data for the first frequency band through a Fourier transform. The method according to claim 1,
Wherein the second frequency data generator generates the third frequency data and the fourth frequency data for the second frequency band through a Fourier transform. The method according to claim 1,
A high-frequency pass filter for passing a high-frequency component with respect to a sensing value for the first current; And
And a preprocessor for changing a frequency component in the second frequency band with respect to a sensing value passed through the high-pass filter. 10. The method of claim 9,
Wherein the preprocessing unit operates in such a manner that the sensing value crossing the high-pass filter toggles so that the first value and the second value alternate with each other at a point where the preprocessing reference value crosses while the preprocessing reference value rises or falls. An arc detection method performed by an arc detection device,
A first step of sensing a first current flowing in a first line of the system in which an influence of noise due to the operation is detected in a first frequency band including a switching frequency of the power conversion device;
A second step of processing a sensing value for the first current in each of a first time interval and a second time interval to generate first frequency data and second frequency data for the first frequency band;
A third step of determining an arc occurrence possibility of the system according to first comparison data of the first frequency data and the second frequency data;
Wherein when it is determined that there is an arcing possibility in the third step, a sensing value for the first current in each of a third time interval and a fourth time interval having a longer time interval than the first time interval and the second time interval, A fourth step of generating third frequency data and fourth frequency data for a second frequency band including a frequency band lower than the first frequency band by processing the fourth frequency data; And
A fifth step of secondarily determining an arc generation possibility of the system in consideration of second comparison data of the third frequency data and the fourth frequency data;
≪ / RTI > ◈ Claim 12 is abandoned due to registration fee. 12. The method of claim 11,
The first time period and the third time period are time periods before the first load change time point and the second time period and the fourth time period are time periods before the first load change time point, And a time period after the first load change time point. ◈ Claim 13 is abandoned due to registration fee. 13. The method of claim 12,
Wherein the third time period and the fourth time period are respectively 10 times or more times longer than the first time period and the second time period. ◈ Claim 14 is abandoned due to registration fee. 12. The method of claim 11,
Wherein the second frequency band comprises a frequency of the power system or a frequency twice the frequency of the power system. ◈ Claim 15 is abandoned due to registration fee. 12. The method of claim 11,
Wherein the first frequency data, the second frequency data, the third frequency data, and the fourth frequency data are generated through Fourier transform. ◈ Claim 16 is abandoned due to registration fee. 12. The method of claim 11, wherein a pre-processing step of changing a frequency component in the second frequency band with respect to a sensing value for the first current is performed before the fourth step. ◈ Claim 17 is abandoned due to registration fee. 17. The method of claim 16, wherein the preprocessing step is performed by toggling the sensing value for the first current so that the sensing value for the first current alternates between the first value and the second value at each crossing point, Arc detection method.

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