WO2022114543A1 - Code signal-based fiber-optic acoustic sensor - Google Patents

Code signal-based fiber-optic acoustic sensor Download PDF

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WO2022114543A1
WO2022114543A1 PCT/KR2021/015104 KR2021015104W WO2022114543A1 WO 2022114543 A1 WO2022114543 A1 WO 2022114543A1 KR 2021015104 W KR2021015104 W KR 2021015104W WO 2022114543 A1 WO2022114543 A1 WO 2022114543A1
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signal
optical fiber
unit
sensing
light source
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PCT/KR2021/015104
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French (fr)
Korean (ko)
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기송도
김영신
최지원
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주식회사 에니트
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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
    • G01N21/17—Systems in which incident light is modified in accordance with the properties of the material investigated
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N29/00—Investigating or analysing materials by the use of ultrasonic, sonic or infrasonic waves; Visualisation of the interior of objects by transmitting ultrasonic or sonic waves through the object
    • G01N29/04—Analysing solids

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  • the present invention relates to a code signal-based optical fiber acoustic sensor, and more particularly, to a code signal-based optical fiber acoustic sensor capable of improving the detection accuracy of an acoustic signal.
  • a distributed optical fiber sensor that installs and operates an optical fiber over a long distance of about 10 km has been published in various ways, such as Korean Patent Registration No. 10-1223105.
  • This distributed optical fiber sensor utilizes the scattering phenomenon within the optical fiber.
  • the distributed optical fiber sensor measures the intensity of backscattered light in the optical fiber that is reflected and returned differently depending on the physical quantity acting on a specific position of the optical fiber, and can be constructed to detect various physical quantities such as deformation in addition to temperature.
  • DAS distributed acoustic sensor
  • the optical fiber acoustic sensor is a sensor that measures the scattered light generated due to the non-uniform distribution of the density of the optical fiber from the light traveling inside the optical fiber, and can obtain backscattered light proportional to the intensity of the pulsed light.
  • the present invention was devised to solve the above requirements, and it transmits optical signals coded in different patterns and decodes the received scattered light signals to improve the signal-to-noise ratio.
  • the purpose is to provide a sensor.
  • a code signal-based optical fiber acoustic sensor comprises: a light source for emitting a pulse light having a pattern corresponding to an indicated code signal; an optical circulator outputting light emitted from the light source unit and inputted to an input terminal to a sensing terminal, and outputting light traveling backward from the sensing terminal to a detection terminal; a sensing optical fiber connected to the sensing terminal and installed to be distributed over a measurement target area; a photodetector configured to detect Rayleigh backscattered light output from the detecting end of the optical circulator; Controls the driving of the light source so that code signals belonging to a set coding length are output from the light source, and decodes the signal output from the photodetector for Rayleigh backscattered light reflected back in response to sound from the sensing optical fiber. and a control unit that analyzes and processes the sound signal for each position of the sensing optical fiber.
  • the sensing optical fiber is mounted to be disposed inside at least one of a transformer, a receiver panel, and a switchboard.
  • control unit comprises: an optical waveform coding unit for generating a coding signal belonging to a set coding length and outputting it to the light source unit; an optical waveform decoding unit for decoding and processing the coded signal from the signal output from the photodetector; Analyzes an acoustic signal from a signal output from the optical waveform decoding unit, determines whether the analyzed acoustic signal corresponds to a partial discharge, and outputs partial equation generation information through an output unit when determined to be a partial discharge, and the optical waveform coding unit and a signal processing unit which provides the coding length information set in the , and controls the optical waveform coding unit.
  • control unit determines and applies the k value to any one of 7 and 8.
  • the signal-to-noise ratio and the acoustic signal measurement speed can also be improved.
  • FIG. 1 is a view showing a code signal-based optical fiber acoustic sensor according to the present invention
  • FIG. 2 is a flowchart showing the sound signal measurement process of the control unit of FIG. 1;
  • FIG. 3 is a waveform diagram showing an example of a code signal transmitted through the light source unit of FIG. 1 and a signal received by the photodetector corresponding thereto;
  • 4 to 7 are graphs for explaining an example of a method for determining the occurrence of partial discharge in the control unit of FIG. 1 .
  • FIG. 1 is a view showing a code signal-based optical fiber acoustic sensor according to the present invention.
  • the code signal-based optical fiber acoustic sensor 100 includes a light source unit 110 , an optical circulator 120 , a sensing optical fiber 130 , a light detection unit 140 , a control unit 160 and An output unit 180 is provided.
  • the light source unit 110 emits pulsed light having a pattern corresponding to the code signal instructed by the control unit 160 .
  • the light source unit 110 is constructed of a light source 112 and a waveform generator 114 .
  • the light source 112 outputs pulsed light corresponding to the pulse waveform output from the waveform generator 114 .
  • the waveform generating unit 114 generates a pulse waveform corresponding to the code signal output from the optical waveform coding unit 161 of the control unit 160 to drive the light source 112 .
  • the optical circulator 120 outputs the light emitted from the light source unit 110 and input to the input terminal 120a to the sensing terminal 120b, and the light traveling in reverse from the sensing terminal 120b to the detection terminal 120c. print out
  • the sensing optical fiber 130 is connected to the sensing end 120b of the optical circulator 120 and is installed to be distributed over the measurement target area.
  • the sensing optical fiber 130 is mounted on the mounting target element 12 inside the housing 10 corresponding to any one of a transformer, a switchboard, and a switchboard.
  • the photodetector 140 detects the Rayleigh backscattered light output from the detection terminal 120c of the optical circulator 120 and outputs it as an electrical signal.
  • the Rayleigh backscattered light is an optical signal outputted through the sensing terminal 120b and the detection terminal 120c while being scattered to correspond to the pulsed light incident from the sensing optical fiber 130 and proceeding in the reverse direction.
  • the photodetector 140 may include a wavelength filter that filters Rayleigh backscattered light from the light output from the detection terminal 120c and a photodetector that outputs an electrical signal corresponding to the intensity of light output from the wavelength filter.
  • the control unit 160 controls the driving of the light source unit 110 so that code signals belonging to the set coding length are output from the light source unit 110, and in response to the sound from the sensing optical fiber 130 and reflected back in response to the Rayleigh reverse scattering light.
  • the signal output from the optical detection unit 140 is decoded to analyze and process the sound signal for each position of the sensing optical fiber 130 .
  • the control unit 160 includes an optical waveform coding unit 161 , an optical waveform decoding unit 162 , and a signal processing unit 170 .
  • the optical waveform coding unit 161 generates a coding signal belonging to the coding length set by the signal processing unit 170 and outputs it to the waveform generating unit 114 of the light source unit 110 .
  • the coding signal will be described later.
  • the optical waveform decoding unit 162 decodes the signal output from the optical detection unit 140 to correspond to the coded signal output from the optical waveform coding unit 161 and provides the decoded signal to the signal processing unit 170 .
  • the signal processing unit 170 analyzes the sound signal from the signal output from the optical waveform decoding unit 162 , determines whether the analyzed sound signal corresponds to the partial discharge, and when it is determined as the partial discharge, through the output unit 180 .
  • the partial discharge generation information is output, the coding length information set in the optical waveform coding unit 161 is provided, and the optical waveform coding unit 161 is controlled.
  • the output unit 180 may be a communication interface for transmitting the generation information to the transmission target destination or a display unit displaying the generation information may be applied.
  • a coding signal generation and processing process of the control unit 160 in this structure will be described with reference to FIG. 2 .
  • k is an integer greater than or equal to 1, and the coding length L may be set in advance or configured to be set by selecting it through a separate manipulation unit (not shown).
  • control unit 160 is constructed to determine and apply the k value to any one of 7 and 8.
  • an H matrix which is a Hadamard matrix of 2K length, is generated (step 220).
  • the Hadamard matrix is a matrix defined by Equation 1 below.
  • H 1 0
  • H's complement matrix That is, if A is 0 becomes 1, and if A is 1 becomes 0.
  • S is generated by deleting the first row and first column of H 2 k (step 230).
  • each row of the generated S is determined as a code signal and transmitted (step 240).
  • Equation 2 the Hadamard matrix generated from Equation 1 is obtained as shown in Equation 2 below.
  • Equation (3) S obtained by deleting the first row and first column from Equation (2) is obtained as in Equation (3).
  • ⁇ 101 ⁇ in the first row of S is determined as the first code signal
  • ⁇ 011 ⁇ in the second row is determined as the second code signal
  • ⁇ 110 ⁇ in the third row is determined as the third code signal.
  • These first to third code signals are generated as waveforms denoted by a1, b1, and c1 in FIG. 3 .
  • the determined first code signal, the second code signal, and the third code signal are sequentially transmitted according to a set transmission period.
  • control unit 160 decodes the received signal corresponding to each code signal, that is, the transmitted code signal (a1, b1, c1) corresponding to the received signal as shown in a2, b2, c2 of FIG. 3, and ( Step 250), a sound signal for each position of the sensing optical fiber 130 is calculated from the decoded signal (step 260).
  • d is an interval of bits serving as an identification unit of a code signal.
  • the signal-to-noise ratio and measurement speed can also be improved by sequentially transmitting code signals of different patterns and decoding and processing the received signals.
  • the signal processing unit 170 may be constructed to analyze the phase of the received and processed sound signal to determine the discharge type.
  • the signal processing unit 170 may be constructed to analyze the phase of the received and processed sound signal to determine the discharge type.
  • the signal processing unit 170 may be constructed to analyze the phase of the received and processed sound signal to determine the discharge type.
  • the signal processing unit 170 may be constructed to analyze the phase of the received and processed sound signal to determine the discharge type.
  • the signal processing unit 170 may be constructed to analyze the phase of the received and processed sound signal to determine the discharge type.
  • the signal processing unit 170 may be constructed to analyze the phase of the received and processed sound signal to determine the discharge type.
  • the signal processing unit 170 records information on the reference patterns for each type capable of discriminating the type of discharge according to the phase distribution of the sound signal, and determines the type of discharge by comparing the similarity with the recorded reference patterns. should be built to do so.
  • the signal-to-noise ratio and the acoustic signal measurement speed can also be improved.

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Abstract

The present invention relates to a code signal-based fiber-optic acoustic sensor comprising: a light source unit which emits pulsed light in a pattern corresponding to a designated code signal; an optical circulator which outputs, to a sensing terminal, light emitted from the light source unit and incident to an input terminal, and outputs, to a detection terminal, light traveling back from the sensing terminal; a sensing optical fiber which is connected to the sensing terminal and arranged to be distributed in a region to be measured; an optical detection unit which detects Rayleigh back scattered light output from the detection terminal of the optical circulator; and a control unit which controls driving of the light source unit such that code signals belonging to a predetermined coding length are output from the light source unit, and decodes a signal output from the optical detection unit with respect to the Rayleigh back scattered light reflected back from the sensing optical fiber in response to sounds to analyze and process a sound signal for each position of the sensing optical fiber. The code signal-based fiber-optic acoustic sensor provides an advantage in that both the signal-to-noise ratio and the sound signal measurement speed can be improved.

Description

코드신호 기반 광섬유 음향센서Code signal based fiber optic acoustic sensor
본 발명은 코드신호 기반 광섬유 음향센서에 관한 것으로서, 상세하게는 음향신호의 검출 정밀도를 향상시킬 수 있도록 된 코드신호 기반 광섬유 음향센서에 관한 것이다.The present invention relates to a code signal-based optical fiber acoustic sensor, and more particularly, to a code signal-based optical fiber acoustic sensor capable of improving the detection accuracy of an acoustic signal.
광섬유를 10 km 내외의 장거리에 걸쳐 설치하여 운영하는 분포형 광섬유 센서는 국내 등록특허 제10-1223105호 등 다양하게 게시되어 있다.A distributed optical fiber sensor that installs and operates an optical fiber over a long distance of about 10 km has been published in various ways, such as Korean Patent Registration No. 10-1223105.
이러한 분포형 광섬유 센서는 광섬유 내 산란현상을 이용한다. 분포형 광섬유센서는 광섬유의 특정 위치에 작용하는 물리량에 따라 다르게 반사되어 돌아오는 광섬유 내 후방 산란광의 세기를 측정하는 것으로 온도 이외에도 변형 등 다양한 물리량을 검출하도록 구축될 수 있다.This distributed optical fiber sensor utilizes the scattering phenomenon within the optical fiber. The distributed optical fiber sensor measures the intensity of backscattered light in the optical fiber that is reflected and returned differently depending on the physical quantity acting on a specific position of the optical fiber, and can be constructed to detect various physical quantities such as deformation in addition to temperature.
이러한 분포형 광섬유 센서 중 레일레이(Rayleigh) 산란을 이용하는 광섬유 음향센서(DAS: Distributed Acoustic Sensor)가 있다.Among these distributed optical fiber sensors, there is a distributed acoustic sensor (DAS) that uses Rayleigh scattering.
광섬유 음향센서는 광섬유 내부를 진행하는 광으로부터 광섬유의 밀도의 불균일 분포에 기인하여 발생하는 산란광을 측정하는 센서로, 펄스광의 세기에 비례하는 후방 산란광을 얻을 수 있다. The optical fiber acoustic sensor is a sensor that measures the scattered light generated due to the non-uniform distribution of the density of the optical fiber from the light traveling inside the optical fiber, and can obtain backscattered light proportional to the intensity of the pulsed light.
그런데, 단발 형태의 펄스광을 송출하는 광섬유 음향센서의 경우 잡음에 의한 측정정밀도가 떨어질 수 있어 신호대 잡음비를 더욱 향상시키면서 측정시간도 단축할 수 있는 방안이 요구되고 있다.However, in the case of an optical fiber acoustic sensor that transmits single-shot pulsed light, the measurement precision due to noise may be lowered, so a method for further improving the signal-to-noise ratio and shortening the measurement time is required.
본 발명은 상기와 같은 요구사항을 해결하기 위하여 창안된 것으로서, 상호 다른패턴으로 코드화된 광신호를 송출하고, 수신된 산란광 신호를 디코딩 하는 과정을 거쳐 신호대 잡음비를 향상시킬 수 있는 코드신호 기반 광섬유 음향센서를 제공하는데 그 목적이 있다.The present invention was devised to solve the above requirements, and it transmits optical signals coded in different patterns and decodes the received scattered light signals to improve the signal-to-noise ratio. The purpose is to provide a sensor.
상기의 목적을 달성하기 위하여 본 발명에 따른 코드신호 기반 광섬유 음향센서는 지시된 코드신호에 대응하는 패턴의 펄스광을 출사하는 광원부와; 상기 광원부에서 출사되어 입력단으로 입력된 광을 센싱단으로 출력하고, 상기 센싱단에서 역으로 진행하는 광을 검출단으로 출력하는 광써큘레이터와; 상기 센싱단에 접속되어 측정대상 영역에 분포되게 설치된 센싱광섬유와; 상기 광써큘레이터의 검출단에서 출력되는 레일레이 역산란광을 검출하는 광검출부와; 설정된 코딩길이에 속하는 코드신호들이 상기 광원부에서 출력되게 상기 광원부의 구동을 제어하고, 상기 센싱광섬유에서 음향에 대응되어 역으로 반사되는 레일레이 역산란광에 대해 상기 광검출부에서 출력되는 신호를 디코딩하여 상기 센싱광섬유의 위치별 음향신호를 분석처리하는 제어유니트;를 구비한다.In order to achieve the above object, a code signal-based optical fiber acoustic sensor according to the present invention comprises: a light source for emitting a pulse light having a pattern corresponding to an indicated code signal; an optical circulator outputting light emitted from the light source unit and inputted to an input terminal to a sensing terminal, and outputting light traveling backward from the sensing terminal to a detection terminal; a sensing optical fiber connected to the sensing terminal and installed to be distributed over a measurement target area; a photodetector configured to detect Rayleigh backscattered light output from the detecting end of the optical circulator; Controls the driving of the light source so that code signals belonging to a set coding length are output from the light source, and decodes the signal output from the photodetector for Rayleigh backscattered light reflected back in response to sound from the sensing optical fiber. and a control unit that analyzes and processes the sound signal for each position of the sensing optical fiber.
바람직하게는 상기 센싱광섬유는 변압기, 수전반 및 배전반 중 적어도 하나에 내부에 배치되게 장착된다.Preferably, the sensing optical fiber is mounted to be disposed inside at least one of a transformer, a receiver panel, and a switchboard.
또한, 상기 제어유니트는 설정된 코딩길이에 속하는 코딩신호를 생성하여 상기 광원부에 출력하는 광파형 코딩부와; 상기 광검출부에서 출력되는 신호로부터 상기 코딩신호에 대응되게 디코딩 처리하는 광파형 디코딩부와; 상기 광파형 디코딩부에서 출력되는 신호로부터 음향신호를 분석하고, 분석된 음향신호가 부분방전에 해당하는 지를 판단하고, 부분방전으로 판단되면 출력부를 통해 부분방정 발생정보를 출력하며 상기 광파형 코딩부에 설정된 코딩길이 정보를 제공하고, 상기 광파형 코딩부를 제어하는 신호처리부;를 구비한다.In addition, the control unit comprises: an optical waveform coding unit for generating a coding signal belonging to a set coding length and outputting it to the light source unit; an optical waveform decoding unit for decoding and processing the coded signal from the signal output from the photodetector; Analyzes an acoustic signal from a signal output from the optical waveform decoding unit, determines whether the analyzed acoustic signal corresponds to a partial discharge, and outputs partial equation generation information through an output unit when determined to be a partial discharge, and the optical waveform coding unit and a signal processing unit which provides the coding length information set in the , and controls the optical waveform coding unit.
바람직하게는 상기 제어유니트는 코딩길이(L)에 대해 L=2K-1로 결정하고, 2K 길이의 하다마드행렬(Hadamard matrix)인 H행렬를 생성한 후, H의 첫행과 첫열을 지운 S를 생성하고, 생성된 S의 각행을 코드신호로 결정하고, k는 1이상의 정수이다.Preferably, the control unit determines L = 2 K -1 for the coding length (L), generates an H matrix, which is a Hadamard matrix of 2 K length, and then deletes the first row and first column of H. , and each row of the generated S is determined as a code signal, and k is an integer greater than or equal to 1.
더욱 바람직하게는 상기 제어유니트는 상기 k값을 7과 8중 어느 하나로 결정하여 적용한다.More preferably, the control unit determines and applies the k value to any one of 7 and 8.
본 발명에 따른 코드신호 기반 광섬유 음향센서에 의하면, 신호대 잡음비 및 음향신호 측정속도도 향상시킬 수 있는 장점을 제공한다.According to the code signal-based optical fiber acoustic sensor according to the present invention, the signal-to-noise ratio and the acoustic signal measurement speed can also be improved.
도 1은 본 발명에 따른 코드신호 기반 광섬유 음향센서를 나타내 보인 도면이고,1 is a view showing a code signal-based optical fiber acoustic sensor according to the present invention,
도 2는 도 1의 제어유니트의 음향신호 측정과정을 나타내 보인 플로우도이고,FIG. 2 is a flowchart showing the sound signal measurement process of the control unit of FIG. 1;
도 3은 도 1의 광원부를 통해 송출되는 코드신호와 이에 대응되어 광검출부에서 수신되는 신호의 예를 나타내 보인 파형도이고,3 is a waveform diagram showing an example of a code signal transmitted through the light source unit of FIG. 1 and a signal received by the photodetector corresponding thereto;
도 4 내지 도 7은 도 1의 제어유니트에서 부분방전 발생을 판단하는 방식의 예를 설명하기 위한 그래프이다.4 to 7 are graphs for explaining an example of a method for determining the occurrence of partial discharge in the control unit of FIG. 1 .
이하, 첨부된 도면을 참조하면서 본 발명의 바람직한 실시예에 따른 코드신호 기반 광섬유 음향센서를 더욱 상세하게 설명한다.Hereinafter, a code signal-based optical fiber acoustic sensor according to a preferred embodiment of the present invention will be described in more detail with reference to the accompanying drawings.
도 1은 본 발명에 따른 코드신호 기반 광섬유 음향센서를 나타내 보인 도면이다.1 is a view showing a code signal-based optical fiber acoustic sensor according to the present invention.
도 1을 참조하면, 본 발명에 따른 코드신호 기반 광섬유 음향센서(100)는 광원부(110), 광써큘레이터(120), 센싱광섬유(130), 광검출부(140), 제어유니트(160) 및 출력부(180)를 구비한다.Referring to FIG. 1 , the code signal-based optical fiber acoustic sensor 100 according to the present invention includes a light source unit 110 , an optical circulator 120 , a sensing optical fiber 130 , a light detection unit 140 , a control unit 160 and An output unit 180 is provided.
광원부(110)는 제어유니트(160)로부터 지시된 코드신호에 대응하는 패턴의 펄스광을 출사한다.The light source unit 110 emits pulsed light having a pattern corresponding to the code signal instructed by the control unit 160 .
광원부(110)는 광원(112) 및 파형발생부(114)로 구축되어 있다.The light source unit 110 is constructed of a light source 112 and a waveform generator 114 .
광원(112)은 파형발생부(114)에서 출력되는 펄스파형에 대응되는 펄스광을 출력한다.The light source 112 outputs pulsed light corresponding to the pulse waveform output from the waveform generator 114 .
파형발생부(114)는 제어유니트(160)의 광파형 코딩부(161)에서 출력되는 코드신호에 대응되는 펄스파형을 발생하여 광원(112)을 구동한다. The waveform generating unit 114 generates a pulse waveform corresponding to the code signal output from the optical waveform coding unit 161 of the control unit 160 to drive the light source 112 .
광써큘레이터(120)는 광원부(110)에서 출사되어 입력단(120a)으로 입력된 광을 센싱단(120b)으로 출력하고, 센싱단(120b)에서 역으로 진행하는 광을 검출단(120c)으로 출력한다.The optical circulator 120 outputs the light emitted from the light source unit 110 and input to the input terminal 120a to the sensing terminal 120b, and the light traveling in reverse from the sensing terminal 120b to the detection terminal 120c. print out
센싱광섬유(130)는 광써큘레이터(120)의 센싱단(120b)에 접속되어 측정대상 영역에 분포되게 설치되어 있다.The sensing optical fiber 130 is connected to the sensing end 120b of the optical circulator 120 and is installed to be distributed over the measurement target area.
도시된 예에서 센싱광섬유(130)는 변압기, 수전반 및 배전반 중 어느 하나에 해당하는 함체(10)의 내부의 장착대상 요소(12)에 장착되어 있다.In the illustrated example, the sensing optical fiber 130 is mounted on the mounting target element 12 inside the housing 10 corresponding to any one of a transformer, a switchboard, and a switchboard.
광검출부(140)는 광써큘레이터(120)의 검출단(120c)에서 출력되는 레일레이 역산란광을 검출하여 전기적 신호로 출력한다. 여기서 레일레이 역산란광은 센싱광섬유(130)에서 입사된 펄스광에 대응되게 산란되어 역으로 진행되면서 센싱단(120b) 및 검출단(120c)을 통해 출력되는 광신호이다.The photodetector 140 detects the Rayleigh backscattered light output from the detection terminal 120c of the optical circulator 120 and outputs it as an electrical signal. Here, the Rayleigh backscattered light is an optical signal outputted through the sensing terminal 120b and the detection terminal 120c while being scattered to correspond to the pulsed light incident from the sensing optical fiber 130 and proceeding in the reverse direction.
광검출부(140)에는 검출단(120c)에서 출력되는 광으로부터 레일레이 역산란광을 필터링하는 파장필터와 파장필터에서 출력되는 광의 세기에 대응되는 전기적 신호를 출력하는 광검출기로 구축될 수 있다.The photodetector 140 may include a wavelength filter that filters Rayleigh backscattered light from the light output from the detection terminal 120c and a photodetector that outputs an electrical signal corresponding to the intensity of light output from the wavelength filter.
제어유니트(160)는 설정된 코딩길이에 속하는 코드신호들이 광원부(110)에서 출력되게 광원부(110)의 구동을 제어하고, 센싱광섬유(130)에서 음향에 대응되어 역으로 반사되는 레일레이 역산란광에 대해 광검출부(140)에서 출력되는 신호를 디코딩하여 센싱광섬유(130)의 위치별 음향신호를 분석처리한다.The control unit 160 controls the driving of the light source unit 110 so that code signals belonging to the set coding length are output from the light source unit 110, and in response to the sound from the sensing optical fiber 130 and reflected back in response to the Rayleigh reverse scattering light. In response, the signal output from the optical detection unit 140 is decoded to analyze and process the sound signal for each position of the sensing optical fiber 130 .
제어유니트(160)는 광파형 코딩부(161), 광파형 디코딩부(162) 및 신호처리부(170)를 구비한다.The control unit 160 includes an optical waveform coding unit 161 , an optical waveform decoding unit 162 , and a signal processing unit 170 .
광파형코딩부(161)는 신호처리부(170)로부터 설정된 코딩길이에 속하는 코딩신호를 생성하여 광원부(110)의 파형발생부(114)에 출력한다. 여기서 코딩신호에 대해서는 후술한다.The optical waveform coding unit 161 generates a coding signal belonging to the coding length set by the signal processing unit 170 and outputs it to the waveform generating unit 114 of the light source unit 110 . Here, the coding signal will be described later.
광파형 디코딩부(162)는 광검출부(140)에서 출력되는 신호로부터 광파형 코딩부(161)에서 출력한 코딩신호에 대응되게 디코딩 처리하여 신호처리부(170)에 제공한다.The optical waveform decoding unit 162 decodes the signal output from the optical detection unit 140 to correspond to the coded signal output from the optical waveform coding unit 161 and provides the decoded signal to the signal processing unit 170 .
신호처리부(170)는 광파형 디코딩부(162)에서 출력되는 신호로부터 음향신호를 분석하고, 분석된 음향신호가 부분방전에 해당하는 지를 판단하고, 부분방전으로 판단되면 출력부(180)를 통해 부분방전 발생정보를 출력하며 광파형 코딩부(161)에 설정된 코딩길이 정보를 제공하고, 광파형 코딩부(161)를 제어한다.The signal processing unit 170 analyzes the sound signal from the signal output from the optical waveform decoding unit 162 , determines whether the analyzed sound signal corresponds to the partial discharge, and when it is determined as the partial discharge, through the output unit 180 . The partial discharge generation information is output, the coding length information set in the optical waveform coding unit 161 is provided, and the optical waveform coding unit 161 is controlled.
여기서, 출력부(180)는 전송대상 수신처로 생성정보를 송신하는 통신인터페이스 또는 생성정보를 표시하는 표시부가 적용될 수 있다.Here, the output unit 180 may be a communication interface for transmitting the generation information to the transmission target destination or a display unit displaying the generation information may be applied.
이러한 구조에서 제어유니트(160)의 코딩신호 생성 및 처리 과정을 도 2를 참조하여 설명한다.A coding signal generation and processing process of the control unit 160 in this structure will be described with reference to FIG. 2 .
먼저, 제어유니트(160)는 코딩길이(L)에 대해 L=2K-1로 결정한다(단계 210). 여기서, k는 1이상의 정수이고, 코딩길이(L)는 미리 설정되거나 별도의 조작부(미도시)를 통해 선택하여 설정할 수 있게 구축될 수 있다.First, the control unit 160 determines that L = 2 K -1 for the coding length L (step 210). Here, k is an integer greater than or equal to 1, and the coding length L may be set in advance or configured to be set by selecting it through a separate manipulation unit (not shown).
바람직하게는 제어유니트(160)는 k값을 7과 8중 어느 하나로 결정하여 적용하도록 구축된다.Preferably, the control unit 160 is constructed to determine and apply the k value to any one of 7 and 8.
다음은 2K 길이의 하다마드행렬(hadamard matrix)인 H행렬를 생성한다(단계 220). 하다마드 행렬은 아래의 수학식 1로 정의되는 행렬이다.Next, an H matrix, which is a Hadamard matrix of 2K length, is generated (step 220). The Hadamard matrix is a matrix defined by Equation 1 below.
Figure PCTKR2021015104-appb-M000001
Figure PCTKR2021015104-appb-M000001
여기서, H1=0이고,
Figure PCTKR2021015104-appb-I000001
는 H의 보수행렬이다. 즉, A가 0인 경우
Figure PCTKR2021015104-appb-I000002
는 1이되고, A가 1인 경우
Figure PCTKR2021015104-appb-I000003
는 0이 된다.where H 1 =0,
Figure PCTKR2021015104-appb-I000001
is H's complement matrix. That is, if A is 0
Figure PCTKR2021015104-appb-I000002
becomes 1, and if A is 1
Figure PCTKR2021015104-appb-I000003
becomes 0.
이후, H2 k의 첫행과 첫열을 지운 S를 생성한다(단계 230). Thereafter, S is generated by deleting the first row and first column of H 2 k (step 230).
다음은 생성된 S의 각행을 코드신호로 결정하고 송신한다(단계 240).Next, each row of the generated S is determined as a code signal and transmitted (step 240).
이러한 과정에 대해 설명의 복잡성을 피하기 위해 k가 2인 경우에 대해 설명하면, 수학식 1로부터 생성되는 하다마드 행렬은 아래의 수학식 2와 같이 구해진다. In order to avoid the complexity of this process, if k is 2, the Hadamard matrix generated from Equation 1 is obtained as shown in Equation 2 below.
Figure PCTKR2021015104-appb-M000002
Figure PCTKR2021015104-appb-M000002
또한, 수학식2로부터 첫행과 첫열을 지운 S는 수학식 3과 같이 얻어진다.Also, S obtained by deleting the first row and first column from Equation (2) is obtained as in Equation (3).
Figure PCTKR2021015104-appb-M000003
Figure PCTKR2021015104-appb-M000003
따라서, S의 첫 행의 {101}이 제1코드신호로 결정되고, 둘째 행의 {011}이 제2코드신호로 결정되고, 셋째 행의 {110}이 제3코드신호로 결정된다. 이러한 제1 내지 제3코드신호는 도 3의 a1, b1, c1으로 표기된 파형으로 생성된다.Accordingly, {101} in the first row of S is determined as the first code signal, {011} in the second row is determined as the second code signal, and {110} in the third row is determined as the third code signal. These first to third code signals are generated as waveforms denoted by a1, b1, and c1 in FIG. 3 .
이후, 결정된 제1코드신호, 제2코드신호 및 제3코드신호를 순차적으로 설정된 송신주기에 맞춰 송신한다.Thereafter, the determined first code signal, the second code signal, and the third code signal are sequentially transmitted according to a set transmission period.
또한, 제어유니트(160)는 각 코드신호에 대응하여 수신된 신호 즉, 도 3의 a2, b2, c2와 같이 수신된 신호에 대해 송신 코드신호(a1, b1, c1)에 대응되게 디코딩하고(단계 250), 디코딩된 신호로부터 센싱광섬유(130)의 위치별 음향신호를 산출한다(단계 260). 도 3에서 d는 코드신호의 식별단위가 되는 비트의 간격이다. In addition, the control unit 160 decodes the received signal corresponding to each code signal, that is, the transmitted code signal (a1, b1, c1) corresponding to the received signal as shown in a2, b2, c2 of FIG. 3, and ( Step 250), a sound signal for each position of the sensing optical fiber 130 is calculated from the decoded signal (step 260). In FIG. 3, d is an interval of bits serving as an identification unit of a code signal.
이러한 신호처리방식에 의하면 상호 다른 패턴의 코드신호를 순차적으로 송출하고, 수신된 신호에 대해 디코딩하여 처리함으로써 신호대 잡음비 및 측정속도도 향상시킬 수 있다. According to this signal processing method, the signal-to-noise ratio and measurement speed can also be improved by sequentially transmitting code signals of different patterns and decoding and processing the received signals.
한편, 신호처리부(170)에는 수신처리된 음향신호의 위상을 분석하여 방전종류를 판별하도록 구축될 수 있다. 일 예로서, 도 4에 도시된 패턴과 같은 분포의 위상분포도를 갖는 음향이 수신된 경우 금속이 돌출된 것으로 판단하고, 도 5에 도시된 패턴과 같은 분포의 위상분포도를 갖는 음향이 수신된 경우 보이드 방전으로 판단하고, 도 6에 도시된 패턴과 같은 분포의 위상분포도를 갖는 음향이 수신된 경우 자유도체 방전으로 판단하고, 도 7에 도시된 패턴과 같은 분포의 위상분포도를 갖는 음향이 수신된 경우 부유도체 방전으로 판단한다.On the other hand, the signal processing unit 170 may be constructed to analyze the phase of the received and processed sound signal to determine the discharge type. As an example, when a sound having the same distribution as the pattern shown in FIG. 4 is received, it is determined that the metal is protruding, and when the sound having the same distribution as the pattern shown in FIG. 5 is received When it is determined as a void discharge, and when a sound having the same distribution as the pattern shown in FIG. 6 is received, it is determined as a free conductor discharge, and the sound having the same distribution as the pattern shown in FIG. 7 is received. In this case, it is judged as floating conductor discharge.
이를 위해 신호처리부(170)에는 음향신호의 위상 분포에 따른 방전유형 종류를 판별할 수 있는 종류별 기준 패턴들에 대한 정보가 기록되어 있고, 기록된 기준 패턴들과의 유사성을 비교하여 방전종류를 판단하도록 구축되면 된다.To this end, the signal processing unit 170 records information on the reference patterns for each type capable of discriminating the type of discharge according to the phase distribution of the sound signal, and determines the type of discharge by comparing the similarity with the recorded reference patterns. should be built to do so.
이상에서 설명된 코드신호 기반 광섬유 음향센서에 의하면, 신호대 잡음비 및 음향신호 측정속도도 향상시킬 수 있는 장점을 제공한다.According to the code signal-based optical fiber acoustic sensor described above, the signal-to-noise ratio and the acoustic signal measurement speed can also be improved.

Claims (5)

  1. 지시된 코드신호에 대응하는 패턴의 펄스광을 출사하는 광원부와;a light source for emitting pulsed light having a pattern corresponding to the indicated code signal;
    상기 광원부에서 출사되어 입력단으로 입력된 광을 센싱단으로 출력하고, 상기 센싱단에서 역으로 진행하는 광을 검출단으로 출력하는 광써큘레이터와;an optical circulator outputting light emitted from the light source unit and inputted to an input terminal to a sensing terminal, and outputting light traveling backward from the sensing terminal to a detection terminal;
    상기 센싱단에 접속되어 측정대상 영역에 분포되게 설치된 센싱광섬유와;a sensing optical fiber connected to the sensing terminal and installed to be distributed over a measurement target area;
    상기 광써큘레이터의 검출단에서 출력되는 레일레이 역산란광을 검출하는 광검출부와;a photodetector configured to detect Rayleigh backscattered light output from the detecting end of the optical circulator;
    설정된 코딩길이에 속하는 코드신호들이 상기 광원부에서 출력되게 상기 광원부의 구동을 제어하고, 상기 센싱광섬유에서 음향에 대응되어 역으로 반사되는 레일레이 역산란광에 대해 상기 광검출부에서 출력되는 신호를 디코딩하여 상기 센싱광섬유의 위치별 음향신호를 분석처리하는 제어유니트;를 구비하는 것을 특징으로 하는 코드신호 기반 광섬유 음향센서.Controls the driving of the light source so that code signals belonging to a set coding length are output from the light source, and decodes the signal output from the photodetector for Rayleigh backscattered light reflected back in response to sound from the sensing optical fiber. A code signal-based optical fiber acoustic sensor comprising a; a control unit that analyzes and processes the acoustic signal for each position of the sensing optical fiber.
  2. 제1항에 있어서, 상기 센싱광섬유는 변압기, 수전반 및 배전반 중 적어도 하나에 내부에 배치되게 장착된 것을 특징으로 하는 코드신호 기반 광섬유 음향센서.According to claim 1, wherein the sensing optical fiber is a code signal-based optical fiber acoustic sensor, characterized in that it is mounted to be disposed inside at least one of a transformer, a switchboard, and a switchboard.
  3. 제2항에 있어서, 상기 제어유니트는The method of claim 2, wherein the control unit
    설정된 코딩길이에 속하는 코딩신호를 생성하여 상기 광원부에 출력하는 광파형 코딩부와;an optical waveform coding unit generating a coding signal belonging to a set coding length and outputting it to the light source unit;
    상기 광검출부에서 출력되는 신호로부터 상기 코딩신호에 대응되게 디코딩 처리하는 광파형 디코딩부와;an optical waveform decoding unit for decoding and processing the coded signal from the signal output from the photodetector;
    상기 광파형 디코딩부에서 출력되는 신호로부터 음향신호를 분석하고, 분석된 음향신호가 부분방전에 해당하는 지를 판단하고, 부분방전으로 판단되면 출력부를 통해 부분방정 발생정보를 출력하며 상기 광파형 코딩부에 설정된 코딩길이 정보를 제공하고, 상기 광파형 코딩부를 제어하는 신호처리부;를 구비하는 것을 특징으로 하는 코드신호 기반 광섬유 음향센서.Analyzes an acoustic signal from a signal output from the optical waveform decoding unit, determines whether the analyzed acoustic signal corresponds to a partial discharge, and outputs partial equation generation information through an output unit when determined to be a partial discharge, and the optical waveform coding unit Code signal-based optical fiber acoustic sensor comprising a; to provide the coding length information set in the, and to control the optical waveform coding unit.
  4. 제3항에 있어서, 상기 제어유니트는 코딩길이(L)에 대해 4. The method according to claim 3, wherein the control unit controls the coding length (L).
    L=2K-1로 결정하고, 2K 길이의 하다마드행렬(Hadamard matrix)인 H행렬를 생성한 후, H의 첫행과 첫열을 지운 S를 생성하고, 생성된 S의 각행을 코드신호로 결정하고, k는 1이상의 정수인 것을 특징으로 하는 코드신호 기반 광섬유 음향센서.Determine L=2 K -1, generate H matrix, which is a Hadamard matrix with a length of 2 K , create S by deleting the first row and first column of H, and determine each generated row of S as a code signal and k is an integer greater than or equal to 1, a code signal-based optical fiber acoustic sensor.
  5. 제3항에 있어서, 상기 제어유니트는 상기 k값을 7과 8중 어느 하나로 결정하여 적용하는 것을 특징으로 하는 코드신호 기반 광섬유 음향센서.[4] The optical fiber acoustic sensor according to claim 3, wherein the control unit determines and applies the k value to any one of 7 and 8.
PCT/KR2021/015104 2020-11-27 2021-10-26 Code signal-based fiber-optic acoustic sensor WO2022114543A1 (en)

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Publication number Priority date Publication date Assignee Title
KR100641317B1 (en) * 2005-05-11 2006-10-31 이덕기 Method and apparatus for testing optical fiber by using biorthogonal codes and moore-penrose generalized inverses
KR101817295B1 (en) * 2016-07-20 2018-01-10 한국광기술원 Fiber-Optic Distributed Acoustic Sensor
KR20180134253A (en) * 2017-06-08 2018-12-18 광주과학기술원 Fiber-optic acoustic sensor module apparatus and system using coherent optical time-domain reflectormeter method
US20190226908A1 (en) * 2018-12-17 2019-07-25 University Of Electronic Science And Technology Of China Distributed acoustic sensing system based on space-division multiplexing with multi-core fiber
KR102066535B1 (en) * 2019-07-04 2020-02-11 한광전기공업주식회사 Partial discharge detection system using optical fiber ultrasonic sensor in high voltage power system

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR100641317B1 (en) * 2005-05-11 2006-10-31 이덕기 Method and apparatus for testing optical fiber by using biorthogonal codes and moore-penrose generalized inverses
KR101817295B1 (en) * 2016-07-20 2018-01-10 한국광기술원 Fiber-Optic Distributed Acoustic Sensor
KR20180134253A (en) * 2017-06-08 2018-12-18 광주과학기술원 Fiber-optic acoustic sensor module apparatus and system using coherent optical time-domain reflectormeter method
US20190226908A1 (en) * 2018-12-17 2019-07-25 University Of Electronic Science And Technology Of China Distributed acoustic sensing system based on space-division multiplexing with multi-core fiber
KR102066535B1 (en) * 2019-07-04 2020-02-11 한광전기공업주식회사 Partial discharge detection system using optical fiber ultrasonic sensor in high voltage power system

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