KR102453119B1 - Arc detecting device of power supply system and arc detecting method using the same - Google Patents

Abstract

The arc detection device of the power system according to the present invention is a current signal measuring module that measures a current signal flowing in the power system using a current sensor, removes noise included in the current signal, and converts an analog current signal into a digital current signal a data conversion module that analyzes the digital current signal converted by the data conversion module to calculate a power spectral density, and a calculation module for deriving an average power spectral density that is an average value of the power spectral density in an effective frequency range, and the average power It includes an arc detection module that analyzes the spectral density and compares it with an arc accident reference value to detect an abnormal arc. Through this, the present invention provides the effect of improving the reliability of arc accident detection and minimizing the probability of erroneous or non-detection of the arc accident.

Description

ARC DETECTING DEVICE OF POWER SUPPLY SYSTEM AND ARC DETECTING METHOD USING THE SAME

The present invention relates to an arc detection apparatus for a power supply system and an arc detection method using the same.

In general, various loads operated using a voltage of 220V are connected in series and parallel to a power system. In addition, electricity can be safely used in a normal state, but various accidents occur due to various causes.

In particular, the most representative accidents requiring protection are short circuit accidents, ground fault accidents, and arc accidents. In case of short circuit and ground fault accidents, protective equipment such as circuit breakers are used to prepare for accidents, but in the case of arc accidents, the reliability of countermeasures is insufficient.

These arc accidents occur due to damage or aging of the converter, or loosening of connectors. When an arc accident occurs, if not taken promptly, a fire accident may occur due to the high energy generated by the arc. In addition, since this can cause serious human life and property damage, countermeasures against arc accidents are required.

Fires in traditional markets continue to occur. In addition, fire accidents have recently occurred in solar power generation systems. The cause of the fire is a fire caused by an electrical accident, and in particular, it appears to be caused by an arc.

As a countermeasure against such an arc accident, an arc can be detected through an arc detector, and various methods for detecting the arc have been proposed so far. For example, representative methods include a method of using an optical sensor, a method of using a temperature sensor, a method of detecting a change in pressure, a method of detecting an acoustic signal, a method of detecting an electric signal, and the like.

Among them, the method of detecting an electric signal is the most effective as a method of detecting an arc accident in a power system in a branched area. The method of detecting an electrical signal is a detection method based on a change in the corresponding signal by measuring the voltage or current of the power system.

However, existing methods have many problems and limitations when applied to the field due to reliability problems in detecting arc accidents. Accordingly, there is a need for an arc detection method and apparatus capable of minimizing the erroneous or non-detection rate in detecting an arc accident and further improving the reliability of the arc detection.

Matters described in this background section are prepared to promote understanding of the background of the invention, and may include matters that are not already known to those of ordinary skill in the art to which this technology belongs.

An object of the present invention is to propose an arc detection device and an arc detection method capable of effectively detecting an arc accident before a fire occurs due to an arc that may occur in a power supply system.

The arc detection device of a power system according to an embodiment of the present invention includes a current signal measuring module for measuring a current signal flowing in a power system using a current sensor, removing noise included in the current signal, and converting an analog current signal to a digital signal. A data conversion module for converting a current signal, a calculation module for analyzing the digital current signal converted by the data conversion module to calculate a power spectral density, and deriving an average power spectral density that is an average value of the power spectral density in an effective frequency range; And it analyzes the average power spectral density and compares it with an arc accident reference value and includes an arc detection module for detecting an abnormal arc.

The arc detection device of the power system analyzes the magnitude of the arc current in the effective frequency range, the time interval at which the arc current is detected, and the duration of the arc current using an arc detection algorithm to operate the power system normally. and an arc current analysis module for discriminating an abnormal arc current that may cause an arc accident by breaking the insulation of the power system.

When an abnormal power spectral density is detected in a specific frequency domain, the calculation module may calculate the average power spectral density after smoothing data in the specific frequency domain.

The arc detection unit, a reference value comparison unit for comparing the average power spectral density due to the abnormal arc current to an arc accident reference value, and arc detection in which the average power spectral density exceeds the arc accident reference value to minimize erroneous detection of arc detection It may include an arc detection number counting unit for counting the number of times.

The arc detection unit may include an arc determination unit that compares the number of times of arc detection with a set value, and determines as an arc when the number of times of arc detection is equal to or greater than a set value.

In the arc detection method of a power system according to an embodiment of the present invention, the arc detection device detects an arc generated in the power system, the method comprising the steps of measuring a current signal flowing through the power system using a current sensor, the current signal removing noise included in the , converting an analog current signal into a digital current signal, setting an effective frequency range according to a type of the power system, characteristics of the power system, and a type of load, the data conversion unit Analyzing the converted digital current signal to calculate a power spectral density, calculating an average power spectral density that is an average value of the power spectral density in an effective frequency range, and analyzing the average power spectral density to detect an arc includes

The arc detection method of the power system uses an arc detection algorithm to analyze the magnitude of the arc current in the effective frequency range, the time interval at which the arc current is detected, and the duration of the arc current to operate the power system normally. The method may further include distinguishing an abnormal arc current that may cause an arc accident by breaking the current and insulation of the power system.

The detecting of the arc may include comparing the average power spectral density caused by the abnormal arc current to an arc accident reference value, and the number of times of arc detection in which the average power spectral density exceeds the arc accident reference value to minimize malfunction of arc detection. , and comparing the number of times of arc detection with a set value, and determining as an arc when the number of times of arc detection is equal to or greater than a set value.

According to the present invention, by deriving the average power spectral density of the current signal flowing through the power supply system and detecting the arc by comparing the average power spectral density with the arc accident reference value, It provides an environment that can improve reliability.

In addition, the present invention analyzes the magnitude of the arc current, the time interval at which the arc current is detected, and the duration of the arc current in the effective frequency range using an arc detection algorithm to distinguish the normal arc current from the abnormal arc current, and the abnormal arc By detecting the arc by deriving the average power spectral density of the current, it prevents unnecessary power system shutdown and provides an environment that can provide a quick cutoff standard for arc accidents.

In addition, in the present invention, when an abnormal power spectral density is detected in a specific frequency domain, by calculating the average power spectral density after smoothing the data in the specific frequency domain, the arc accident is more accurately detected and the probability of erroneous or non-detection. environment to minimize

In addition, the present invention compares the average power spectral density caused by the abnormal arc current to the arc accident reference value, and detects the arc by counting the number of arc detections in which the average power spectral density exceeds the arc accident reference value, thereby erroneous detection of arc detection. Provide an environment that can minimize and improve the reliability of arc accident detection.

In addition, the present invention provides an environment in which the reliability of arc accident detection can be improved by differently setting the effective frequency range and the arc accident reference value of arc detection according to the type of power system, the characteristics of the power system, and the type of load. to provide.

1 is a diagram schematically illustrating an arc detection and interruption system of a power supply system according to an embodiment of the present invention.
2 is a block diagram showing a schematic configuration of an arc detection apparatus according to an embodiment of the present invention.
3 is a flowchart schematically illustrating a process of detecting an arc by measuring a current signal of a power supply system and calculating a power spectral density after data processing of the measured current signal according to an embodiment of the present invention.
4 is a graph illustrating an example of processing abnormal data generated in a specific frequency domain and smoothing the abnormal data into normal data according to an embodiment of the present invention.
5 is a graph showing the power spectrum density of an arc accident and a steady state according to an embodiment of the present invention.
6 is a process of detecting an arc by setting an effective frequency range according to another embodiment of the present invention, classifying an abnormal arc current, comparing the average power spectral density of the abnormal arc current with an arc accident reference value, and counting the number of arc detections It is a flow chart showing briefly.

Hereinafter, preferred embodiments of the present invention will be described in detail based on the accompanying drawings.

Prior to this, the configurations shown in the embodiments and drawings described in the present specification are only the most preferred embodiment of the present invention and do not represent all of the technical spirit of the present invention, so they can be substituted at the time of the present application It should be understood that various equivalents and modifications may be made.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those of ordinary skill in the art to which the present invention pertains can easily implement them. However, the present invention may be embodied in several different forms and is not limited to the embodiments described herein. And in order to clearly explain the present invention in the drawings, parts irrelevant to the description are omitted, and similar reference numerals are attached to similar parts throughout the specification.

Since the size and thickness of each component shown in the drawings are arbitrarily indicated for convenience of description, the present invention is not necessarily limited to the bar shown in the drawings, and the thickness is enlarged to clearly express various parts and regions.

Throughout the specification, when a part "includes" a certain component, it means that other components may be further included, rather than excluding other components, unless otherwise stated. In addition, terms such as “…unit”, “…group”, and “module” described in the specification mean a unit that processes at least one function or operation, which may be implemented as hardware or software or a combination of hardware and software. have.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which the embodiment belongs. Terms such as those defined in a commonly used dictionary should be interpreted as having a meaning consistent with the meaning in the context of the related art, and should not be interpreted in an ideal or excessively formal meaning unless explicitly defined in the present application. does not

In addition, in the description of the embodiment, if it is determined that the detailed description of the related known technology may unnecessarily obscure the gist of the embodiment, the detailed description thereof will be omitted.

Now, an arc detection apparatus and an arc detection method of a power system according to an embodiment of the present invention will be described in detail with reference to FIGS. 1 to 6 .

1 is a diagram schematically illustrating an arc detection and interruption system of a power supply system according to an embodiment of the present invention. At this time, the arc detection and cutoff system 10 shows only a schematic configuration necessary for description according to an embodiment of the present invention, but is not limited to this configuration.

Referring to FIG. 1 , the arc detection and cutoff system 10 according to an embodiment of the present invention is an arc detection device in advance to protect human life and property due to a fire due to an arc accident occurring in the power supply system 20 . (100) detects abnormal arc current.

Here, the arc refers to a discharge phenomenon in which some volatilization is accompanied by an electrode of the power system 20 and continuously emits light between insulators, and includes a normal arc and an abnormal arc.

And, a normal arc can occur even in the normal operation of a light switch or electric motor, which is isolated so as not to ignite the surrounding combustibles. However, an abnormal arc may occur in a deteriorated electric wire and a power distribution system, and may occur mainly in a gap between conductors, an insulator of an electric wire, etc., and may cause an arc accident by breaking the insulation of the power supply system 20 .

Then, the arc detection and interruption system 10 according to an embodiment of the present invention detects an abnormal arc current through the arc detection device 100. By blocking the arc current flowing in the circuit, it is possible to prevent arc accidents and improve the reliability of detecting arc accidents that occur in the early stage in a branched power supply system.

2 is a block diagram showing a schematic configuration of an arc detection apparatus according to an embodiment of the present invention. At this time, the arc detection apparatus 100 shows only a schematic configuration necessary for description according to an embodiment of the present invention, but is not limited to this configuration.

Referring to FIG. 2 , the arc detection apparatus 100 according to an embodiment of the present invention includes a control module 110 , a current signal measurement module 120 , a data conversion module 130 , an arc current analysis module 140 , a calculation module 150 , and an arc detection module 160 .

The control module 110 measures the current signal flowing through the power system 20 to calculate the power spectral density for each frequency section, and derives the average power spectral density that is the average value of the power spectral density in the effective frequency range, and the By analyzing the average power spectral density, it is possible to control the operation of each part to detect an arc by comparing it with an arc accident reference value.

The current signal measuring module 120 measures a current signal flowing through the power supply system 20 using the current sensor 122 . The current sensor 122 may include a current sensor in the form of a Rogowski coil. In addition, the current sensor 122 may be applied to a product having a performance ranging from a commercial frequency range to a maximum of 1 MHz. In addition, the current sensor 122 may be connected to one line of the branched power supply system 20 to detect an arc accident.

The data conversion module 130 removes noise included in the current signal in the current signal measuring module 120 and converts the analog current signal into a digital current signal.

In addition, the data conversion module 130 may include a noise removing unit 132 and a signal converting unit 134 according to an embodiment of the present invention.

The noise removing unit 132 may include a high-pass filter, and may remove noise of a high frequency component included in the current signal measured by the current sensor 122 . For example, the high-pass filter may be configured as a hardware filter using passive elements such as a resistor, an inductor, and a capacitor, and a software filter may be applied as necessary.

The signal converting unit 134 may convert the analog current signal filtered by the noise removing unit 132 into a digital current signal. This is a necessary part for Fourier transform and data processing for arc accident detection.

In addition, the signal converter 134 may convert the digital current signal in the time domain into a current signal in the frequency domain. That is, the digital current signal may be changed to a current signal in the frequency domain through Fourier transform. And, through this, the calculation module 150 may calculate the average value of the power spectral density and the power spectral density of the current signal obtained through the Fourier transform.

The arc current analysis module 140 analyzes the magnitude of the arc current in the effective frequency range, the time interval at which the arc current is detected, and the duration of the arc current by using the arc detection algorithm. And, through this, the arc current analysis module 140 can distinguish between a normal arc current that normally operates the power system and an abnormal arc current that can cause an arc accident by breaking the insulation of the power system.

In addition, the arc current analysis module 140 may include an effective frequency setting unit 142 , an arc current analysis unit 144 , and an arc current determination unit 146 according to an embodiment of the present invention.

The effective frequency setting unit 142 may set an effective frequency range for arc discrimination according to the electrical characteristics of the power system 20 . The effective frequency setting unit 142 may set the effective frequency range differently according to the type of the power system 20 , characteristics of the power system, and the type of load.

More specifically, the effective frequency setting unit 142 is the type of power system 20 (eg, AC, DC), the type of load (eg, light load, outlet load, pump, blower, elevator, It may vary depending on a power load such as an escalator or a power load for air conditioning), and characteristics of a power system (eg, transformer characteristics, overvoltage characteristics, circuit protection characteristics, insulation coordination), and the like. For example, the effective frequency range may be selected from 10 kHz to 100 kHz according to an embodiment of the present invention.

The arc current analyzer 144 may analyze the magnitude of the arc current in the effective frequency range, the time interval at which the arc current is detected, and the duration of the arc current by using the arc detection algorithm.

The arc current determining unit 146 may cause an arc accident by breaking the insulation of the power system and the normal arc current that normally operates the power system 20 using the analysis result of the arc current analyzing unit 144 . The abnormal arc current can be distinguished.

The calculation module 150 may calculate the power spectral density for each frequency section by analyzing the digital current signal converted by the data conversion module 130 for each frequency section. Also, the calculation module 150 may derive an average power spectral density that is an average value of the power spectral density in an effective frequency range.

In addition, the calculation module 150 may obtain results according to various types of arc accidents by using the average power spectral density to obtain normally distributed average value data through a probabilistic statistical technique.

And, from this result, the calculation module 150 may derive an arc accident reference value for an arc accident capable of determining whether or not an arc accident has occurred by comparing it with the average power spectral density. Here, the arc accident reference value may be set differently depending on the type of the power system, the characteristics of the power system, and the type of load.

Also, when an abnormal power spectral density is detected in a specific frequency domain, the calculation module 150 may calculate the average power spectral density after smoothing the data in the specific frequency domain.

In addition, the calculation module 150 may include a data smoothing unit 152 and a power spectral density calculation unit 154 according to an embodiment of the present invention.

When an abnormal power spectral density is detected in a specific frequency domain, the data smoothing unit 152 may smooth data of the specific frequency domain.

The power spectral density calculator 154 may calculate a power spectral density for each frequency section and derive the average power spectral density in an effective frequency range. Also, the power spectral density calculator 154 may analyze electrical characteristics of the power supply system 20 .

In addition, the power spectral density calculation unit 154 may derive the arc accident reference value to detect an abnormal arc current according to the electrical characteristics of the power system 20 .

The arc detection module 160 may analyze the average power spectral density and compare the average power spectral density with the arc accident reference value to detect an abnormal arc or an abnormal arc current.

In addition, the arc detection module 160 may include a reference value comparison unit 162 , an arc detection frequency counting unit 164 , and an arc determination unit 166 according to an embodiment of the present invention.

The reference value comparison unit 162 may compare the average power spectral density due to the abnormal arc current to an arc accident reference value. Here, the arc accident reference value may be set differently depending on the type of the power system, the characteristics of the power system, and the type of load.

The arc detection frequency counting unit 164 may count the number of arc detection times in which the average power spectral density exceeds the arc accident reference value to minimize erroneous detection of arc detection.

The arc determination unit 166 may compare the number of arc detections with a preset value, and when the number of times of arc detection is equal to or greater than a preset value, may determine an abnormal arc.

3 is a flowchart schematically illustrating a process of detecting an arc by measuring a current signal of a power supply system and calculating a power spectral density after data processing of the measured current signal according to an embodiment of the present invention. In this case, the following flowchart will be described using the same reference numerals in connection with the configuration of FIGS. 1 to 2 .

Referring to FIG. 3 , the arc detection apparatus 100 according to an embodiment of the present invention may measure a current signal of the power supply system 20 ( S102 ).

And, the arc detection apparatus 100 according to an embodiment of the present invention may primarily remove noise of a high frequency component through a filter or the like, and convert the analog current signal into a digital current signal (S104). In this case, the filter may include both hardware and software types. In addition, the filtered digital current signal in the time domain may be converted into a current signal in the frequency domain through Fourier transform.

Also, when an abnormal power spectral density is detected in a specific frequency domain, the arc detection apparatus 100 according to an embodiment of the present invention may smooth data of the specific frequency domain ( S106 ).

4 is a graph illustrating an example of processing abnormal data generated in a specific frequency domain and smoothing the abnormal data into normal data according to an embodiment of the present invention.

Referring to FIG. 4 , an effective frequency region of a power spectral density required for arc detection may be a region f1 to f3. In addition, an unnecessary signal in a specific frequency band (eg, f2) may be included in the power spectral density.

These unnecessary signals show very high power spectral density values in a very short frequency range. 4 shows a particularly high power spectral density in the frequency region f2, and this phenomenon may appear at multiple frequency values.

Since the generated power spectral density in a specific frequency region results in increasing the average value in the process of obtaining the overall average value of the power spectral density, a data processing process for this part is required.

Accordingly, the arc detection apparatus 100 according to an embodiment of the present invention may apply various data processing methods for processing the abnormal value or smoothing the data when the abnormal value occurs in the original data as described above. For example, the arc detection apparatus 100 according to an embodiment of the present invention may apply a data outlier detection method or a data smoothing method, and if necessary, apply a statistical technique to smooth or remove an outlier. can do.

As such, the arc detection apparatus 100 according to an embodiment of the present invention performs a data smoothing operation in order to remove a phenomenon in which a very high power spectral density appears in a specific frequency region, thereby improving data readability. have.

Then, the arc detection apparatus 100 according to an embodiment of the present invention may calculate an average power spectral density that is an average value of the power spectral density in an effective frequency range ( S108 ).

And, the arc detection apparatus 100 according to an embodiment of the present invention may analyze the average power spectral density and compare the average power spectral density with the arc accident reference value to detect an abnormal arc (S110). For example, if the average power spectral density is less than or equal to the arc accident reference value, the current signal is measured again, and if it exceeds the arc accident reference value, it is primarily determined as an arc accident.

5 is a graph showing the power spectrum density of an arc accident and a steady state according to an embodiment of the present invention.

Referring to FIG. 5 , the power spectral density in the frequency domain for the current signal in the case of an arc accident and in a steady state is shown. As shown in FIG. 5 , since the difference in power spectral density occurs in the effective frequency range in the case of an arc accident and in a normal state, the arc accident can be easily detected using the difference.

6 is a process of detecting an arc by setting an effective frequency range according to another embodiment of the present invention, classifying an abnormal arc current, comparing the average power spectral density of the abnormal arc current with an arc accident reference value, and counting the number of arc detections It is a flow chart showing briefly. In this case, the following flowchart will be described using the same reference numerals in connection with the configurations of FIGS. 1 to 5 .

Referring to FIG. 6 , the arc detection apparatus 100 according to an embodiment of the present invention may measure a current signal flowing through the power supply system 20 using the current sensor 122 ( S202 ).

Then, the arc detection apparatus 100 according to an embodiment of the present invention may set an effective frequency range for determining whether an abnormal arc is generated (S204). Here, the effective frequency range may be set differently according to the type of the power system 20 , the characteristics of the power system, and the type of load.

For example, the effective frequency range is the type of power system 20 (eg, AC, DC), the type of load (eg, light load, outlet load, pump, blower, elevator, escalator, etc.) load, or power load for air conditioning), and characteristics of the power system (eg, transformer characteristics, overvoltage characteristics, circuit protection characteristics, insulation coordination), and the like. In particular, the effective frequency range may be selected from 10 kHz to 100 kHz according to an embodiment of the present invention.

And, the arc detection apparatus 100 according to an embodiment of the present invention analyzes the magnitude of the arc current in the effective frequency range, the time interval at which the arc current is detected, and the duration of the arc current using an arc detection algorithm. Normal arc current and abnormal arc current may be distinguished (S206).

Then, the arc detection apparatus 100 according to an embodiment of the present invention may calculate the power spectrum density of the abnormal arc current, and may calculate the average power spectrum density in the effective frequency range (S208). Here, the average power spectral density may include an average value of the power spectral density of the abnormal arc current in the effective frequency range.

In addition, the arc detection apparatus 100 according to an embodiment of the present invention may determine whether an arc accident has occurred by comparing the average power spectral density with an arc accident reference value (S210).

Then, the arc detection apparatus 100 according to an embodiment of the present invention counts the number of arc detections when the average power spectral density exceeds the arc accident reference value, and then to minimize the arc detection erroneous detection Arc detection for the current signal of the signal is performed (S212).

And, the arc detection apparatus 100 according to an embodiment of the present invention compares the number of arc detections with a preset value, and when the number of times of arc detection exceeds the preset value, determines that it is an arc accident and detects an arc is detected (S214, S216).

As described above, the arc detection apparatus and arc detection method according to an embodiment of the present invention derive the average power spectral density of the current signal flowing in the power system, and compare the average power spectral density with the arc accident reference value to detect the arc, It provides an environment that can improve the reliability of detecting an arc accident that occurs in the early stage in a branched power system.

In addition, the present invention analyzes the magnitude of the arc current, the time interval at which the arc current is detected, and the duration of the arc current in the effective frequency range using an arc detection algorithm to distinguish the normal arc current from the abnormal arc current, and the abnormal arc By detecting the arc by deriving the average power spectral density of the current, it prevents unnecessary power system shutdown and provides an environment that can provide a quick cutoff standard for arc accidents.

In addition, in the present invention, when an abnormal power spectral density is detected in a specific frequency domain, by calculating the average power spectral density after smoothing the data in the specific frequency domain, the arc accident is more accurately detected and the probability of erroneous or non-detection. environment to minimize

In addition, the present invention compares the average power spectral density caused by the abnormal arc current to the arc accident reference value, and detects the arc by counting the number of arc detections in which the average power spectral density exceeds the arc accident reference value, thereby erroneous detection of arc detection. Provide an environment that can minimize and improve the reliability of arc accident detection.

In addition, the present invention provides an environment in which the reliability of arc accident detection can be improved by differently setting the effective frequency range and the arc accident reference value of arc detection according to the type of power system, the characteristics of the power system, and the type of load. to provide.

The embodiment of the present invention described above is not implemented only through the apparatus and method, but may be implemented through a program for realizing a function corresponding to the configuration of the embodiment of the present invention or a recording medium in which the program is recorded. Such a recording medium may be executed not only in the server but also in the user terminal.

Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto. is within the scope of the right.

Claims (8)

A current signal measurement module that measures the current signal flowing through the power system using a current sensor,
A data conversion module that removes noise included in the current signal and converts an analog current signal into a digital current signal;
The effective frequency range is set differently according to the type of power system, the characteristics of the power system, and the type of load, and the magnitude of the arc current in the effective frequency range using the arc detection algorithm, the time interval at which the arc current is detected, and , an arc current analysis module that analyzes the duration of the arc current to distinguish between a normal arc current that normally operates the power system and an abnormal arc current that can cause an arc accident by breaking the insulation of the power system;
Calculate the power spectral density by analyzing the digital current signal converted by the data conversion module, and derive the average power spectral density that is the average value of the power spectral density in the effective frequency range, but abnormal power spectral density is detected in a specific frequency region In this case, a calculation module for calculating the average power spectral density after smoothing the data in the specific frequency region, and
Arc of a power system comprising an arc detection module that analyzes the average power spectral density and detects an abnormal arc by comparing it with an arc accident reference value set differently depending on the type of the power system, the characteristics of the power system, and the type of load detection device. delete delete In claim 1,
The arc detection module,
A reference value comparison unit for comparing the average power spectral density due to the abnormal arc current to an arc accident reference value, and
and an arc detection frequency counting unit for counting the number of arc detections in which the average power spectral density exceeds the arc accident reference value to minimize erroneous detection of arc detection. In claim 4,
The arc detection module,
and an arc determination unit that compares the number of arc detections with a set value and determines that the arc is an arc when the number of times of arc detection is equal to or greater than a set value. In a method for the arc detection device to detect an arc generated in a power system,
Measuring the current signal flowing through the power system using a current sensor,
removing noise included in the current signal and converting the analog current signal into a digital current signal;
setting an effective frequency range differently according to the type of the power system, the characteristics of the power system, and the type of load;
Insulation of the power system from the normal arc current that normally operates the power system by analyzing the magnitude of the arc current, the time interval at which the arc current is detected, and the duration of the arc current in the effective frequency range using an arc detection algorithm Distinguishing an abnormal arc current that can destroy it and cause an arc accident;
Analyze the digital current signal converted by the data conversion module to calculate the power spectral density, and calculate the average power spectral density, which is the average value of the power spectral density in the effective frequency range, but when abnormal power spectral density is detected in a specific frequency range , calculating the average power spectral density after smoothing the data in the specific frequency region, and
and analyzing the average power spectral density and detecting an abnormal arc by comparing it with an arc accident reference value set differently depending on the type of the power system, the characteristics of the power system, and the type of load. . delete In claim 6,
Detecting the abnormal arc comprises:
Comparing the average power spectral density due to the abnormal arc current to an arc accident reference value;
Counting the number of arc detections in which the average power spectral density exceeds the arc accident reference value to minimize the arc detection malfunction; and
and comparing the number of arc detections with a set value, and determining that the arc is an arc when the number of arc detections is equal to or greater than a set value.

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