KR102462081B1 - Temperature monitoring system for electrical equipment using temperature sensor of fiber optic probe type - Google Patents

Abstract

The present invention relates to a temperature degradation monitoring system for electrical equipment using a temperature sensor of a fiber optic probe type and, more specifically, to a temperature degradation monitoring system for electrical equipment using a temperature sensor of a fiber optic probe type which has a probe on an end of optical fiber to include a temperature-sensitive layer in which the characteristic curve of light changes in accordance with a temperature change to detect and monitor the internal temperature of electric equipment without the effect of vibration or fluid (insulating oil, insulating gas, etc.). To achieve the objective, according to the present invention, the temperature degradation monitoring system for electrical equipment using a temperature sensor of a fiber optic probe type comprises: a degradation detection device detecting electric equipment and the internal temperature of the electric equipment; and a monitoring device monitoring based on the temperature detected by the degradation detection device. The degradation detection device includes: an optical fiber temperature sensor part including optical fiber having a core and a clad layer enclosing the core, and a probe provided on an end of the optical fiber; a light source part outputting an optical signal; an optical circulator receiving the optical signal outputted by the light source part through a first port to allow the optical signal to enter the optical fiber temperature sensor part through a second port, and receiving the optical signal reflected from the optical fiber temperature sensor part through the second port to output the optical signal to a third port; a light detection part receiving the optical signal outputted by the optical circulator to detect a reflection optical signal; and a temperature detection part detecting temperature based on the reflection optical signal detected by the light detection part.

Description

TEMPERATURE MONITORING SYSTEM FOR ELECTRICAL EQUIPMENT USING TEMPERATURE SENSOR OF FIBER OPTIC PROBE TYPE

The present invention relates to a temperature deterioration monitoring system for electrical equipment using a temperature sensor of a fiber optic probe type, and more particularly, by including a temperature sensitive layer in which a characteristic curve of light changes according to a temperature change by configuring a probe at the end of an optical fiber. , It relates to a temperature deterioration monitoring system of electrical equipment using a temperature sensor of the optical fiber probe type that can detect and monitor the internal temperature of electrical equipment without the influence of vibrations or fluids (insulating oil, insulating gas, etc.).

Electrical equipment such as distribution boards, MCCs, transformers, switchgears and circuit breakers are mainly installed in schools, buildings, apartment complexes, factories, etc., where collective power demand is established. .

When the transformer, switchgear, circuit breaker, MOF, etc. inside the electrical equipment including these electrical equipment deteriorate or an overload condition occurs, the temperature inside the electric equipment rises. Fires or internal electrical devices are damaged, resulting in personal injury.

Accordingly, various technologies have been developed for measuring the internal temperature of power equipment such as a switchboard and determining whether there is an abnormality.

As a technology for detecting the temperature inside a switchboard using an optical fiber, an intelligent deterioration diagnosis system for a switchboard having an optical fiber temperature sensor and a method thereof are disclosed in Korean Patent Registration No. 10-1519929.

In the above technology, the optical fiber sensor is composed of two cavity surfaces spaced apart from each other and uses an optical fiber interferometer that extracts the phase difference between incident light and reflected light and the difference in optical path through light interference, the extracted phase difference and Although it is configured to detect a temperature change from a difference in optical paths, it is difficult to form two cavities at regular distances, and incident light or reflected light is lost through the formed cavities, which may cause an error in temperature detection.

In addition, Korean Patent Publication No. 10-1542538 discloses an arc monitoring system of a switchboard having a fiber optic loop sensor.

In the above technology, a scratch pattern is formed on the side of the optical fiber cable in a grid shape and a fiber optic loop sensor is configured with a plurality of light incident parts composed of a band pass filter. Otherwise, an error may occur in the temperature detection.

In addition, in the case of a temperature sensor using an optical fiber, if vibration is generated in the process of detecting the temperature, the phase difference is changed by the vibration while the incident light passes through a cavity (or scratch, etc.) configured in the optical fiber to accurately detect the temperature. An impossible problem arises.

Registered Patent Publication No. 10-1519929 (2015. 05. 07.) Registered Patent Publication No. 10-1542538 (2015. 07. 31.)

The present invention has been devised to solve the above problems, and the problem to be solved in the present invention is to configure a temperature-sensitive layer that changes the characteristic curve of light according to the temperature change at the end of the optical fiber to control the internal temperature of the electrical equipment without the influence of vibration. An object of the present invention is to provide a system for monitoring temperature deterioration of electrical equipment using a temperature sensor of an optical fiber probe type that can be detected.

The temperature deterioration monitoring system of an electrical equipment using a temperature sensor of the optical fiber probe method according to the present invention for solving the above problems is a deterioration detection device for detecting the internal temperature of the electric equipment and the electric equipment, and the deterioration detected by the deterioration detection device. and a monitoring device for monitoring based on temperature, wherein the deterioration detection device includes: an optical fiber having a core and a cladding layer surrounding the core, and an optical fiber temperature sensor unit including a probe configured at an end of the optical fiber; a light source for outputting an optical signal; The optical signal output from the light source unit is received through a first port, is incident on the optical fiber temperature sensor unit through a second port, and the optical signal reflected from the optical fiber temperature sensor unit is received through the second port and is transmitted to a third port. an optical circulator outputting; a photodetector configured to receive an optical signal output from the optical circulator and detect a reflected optical signal; and a temperature detection unit configured to detect a temperature based on the reflected light signal detected by the light detection unit.

Here, the probe includes a temperature-sensitive layer installed at the end of the optical fiber and varying the wavelength and amount of light according to temperature change; a reflective layer disposed outside the temperature-sensitive layer to reflect the light source output from the temperature-sensitive layer; and a protective layer surrounding the optical fiber, the temperature sensitive layer, and the reflective layer.

At this time, the probe removes foreign substances by polishing the surface of the temperature-sensitive layer, deposits a reflective material corresponding to the reflective layer on one surface of the temperature-sensitive layer from which the foreign substances are removed, and then peels the reflective layer deposited on the temperature-sensitive layer In order to prevent development, the coating layer is formed on the upper surface of the reflective layer, then divided into predetermined sizes, and the formed coating layer is removed.

In addition, the temperature-sensitive layer may be made of gallium arsenide (GaAs).

In addition, the refractive index of the heat dissipating adhesive bonding the end surface of the optical fiber and the temperature sensitive layer may be in the range of 1.3 to 1.6.

In addition, the photodetector includes a photodetector; an amplifier circuit for converting and amplifying the current signal of the reflected optical signal obtained by the photodetector into a voltage signal; and a noise reduction circuit for removing noise of the voltage signal amplified by the amplifier circuit.

Also, the photodetector may have a center wavelength of 915 nm and a bandwidth of 85 nm.

According to the present invention, it is possible to detect deterioration and abnormality in temperature by applying it to power equipment such as switchboards, and it is difficult to install a temperature sensor in a gas insulated switchgear (GIS) or transformer insulation oil, dust such as winding It has the advantage of being able to detect and monitor the temperature in adverse conditions such as , moisture and gas.

In addition, since the temperature is detected using the optical signal and the reflected optical signal in the process of measuring the temperature, there is an advantage in that the temperature measurement does not accompany the current, thereby preventing the explosion caused by the temperature measurement.

1 is a schematic configuration diagram in which a temperature deterioration monitoring system of an electrical equipment using a temperature sensor of a fiber optic probe type according to the present invention is applied to a switchboard of an electrical equipment;
2 is a schematic configuration diagram in which a temperature deterioration monitoring system of an electrical equipment using a temperature sensor of an optical fiber probe type according to the present invention is applied to a transformer of an electrical equipment;
3 is a configuration diagram of a deterioration detection device applied to a temperature deterioration monitoring system of an electrical equipment using a temperature sensor of an optical fiber probe method according to the present invention;
4 is a view showing the structure (a) of the optical fiber temperature sensor unit applied to the temperature deterioration monitoring system of electrical equipment using the temperature sensor of the optical fiber probe type according to the present invention and the characteristic curve (b) of the temperature-sensitive layer;
5 is a graph of reflection, absorption and transmission characteristics for a temperature sensitive layer;
6 is a graph of a deposition thickness test for reflectance of a reflective layer applied to a temperature deterioration monitoring system of an electrical equipment using a temperature sensor of an optical fiber probe type according to the present invention;
7 is a graph showing a test of the refractive index of a heat-dissipating adhesive applied to a temperature deterioration monitoring system of an electrical equipment using a temperature sensor of an optical fiber probe type according to the present invention;
8 is a flowchart of a process of manufacturing a probe applied to a temperature deterioration monitoring system of an electrical equipment using a temperature sensor of an optical fiber probe method according to the present invention;
9 is an LD driver circuit diagram of a light source unit applied to a temperature deterioration monitoring system of an electrical equipment using a temperature sensor of an optical fiber probe type according to the present invention;
10 is a TEC circuit diagram of a light source applied to a temperature deterioration monitoring system of an electrical equipment using a temperature sensor of the optical fiber probe method according to the present invention;
11 is a circuit diagram of a photodetector applied to a temperature deterioration monitoring system of an electrical equipment using a temperature sensor of an optical fiber probe type according to the present invention;
12 is a graph showing the performance evaluation graph for the temperature measurement and resolution of the photodetector applied to the temperature deterioration monitoring system of electrical equipment using the temperature sensor of the optical fiber probe method according to the present invention.

Next, a preferred embodiment of a temperature deterioration monitoring system for electrical equipment using a temperature sensor of the optical fiber probe type according to the present invention will be described in detail with reference to the drawings.

Hereinafter, the same reference numerals are used for technical elements having the same function, and repeated detailed descriptions are omitted to avoid overlapping descriptions.

In addition, the examples described below are illustratively shown in order to effectively show the preferred embodiments of the present invention, and should not be construed to limit the scope of the present invention.

The present invention configures a temperature-sensitive layer in which the characteristic curve of light changes according to the temperature change at the end of the optical fiber, thereby detecting and monitoring the temperature inside the switchboard without the influence of vibration. It is about the monitoring system.

1 is a view showing a schematic configuration of a temperature deterioration monitoring system of an electrical equipment using a temperature sensor of an optical fiber probe type according to the present invention is applied to a switchboard of an electrical equipment, and FIG. 2 is a diagram showing a schematic configuration applied to a transformer. .

1 and 2, the temperature deterioration monitoring system of an electrical equipment using a temperature sensor of an optical fiber probe type according to the present invention is a deterioration detection system that detects the temperature of an electric equipment (eg, a switchboard, a transformer, etc.) It is configured to include a device 10 and a monitoring device 20 for monitoring based on the temperature detected by the deterioration detection device 10 .

1 shows an example in which the temperature degradation monitoring system according to the present invention is installed in the switchboard 1 and FIG. 2 shows an example in which the temperature degradation monitoring system according to the present invention is installed in the transformer 2 .

As shown in the accompanying Figure 1, the temperature deterioration monitoring system according to the present invention according to the present invention is configured to detect and monitor the temperature of the internal main part of the switchboard (1).

In addition, as shown in the accompanying Figure 2, the temperature deterioration monitoring system according to the present invention according to the present invention is configured to detect and monitor the temperature of the internal main part of the transformer (2).

In particular, the temperature deterioration monitoring system according to the present invention is made of a probe made of heat-resistant and cold-resistant material in the temperature range of -200 to +260 ° C. SF6) is configured to detect temperature. Accordingly, since it is possible to detect and monitor the temperature of devices and places where temperature detection is difficult, there is an advantage that it can be used universally in electrical installations.

3 is a block diagram of a deterioration detection device applied to a temperature deterioration monitoring system of an electrical equipment using a temperature sensor of an optical fiber probe type according to the present invention.

3, the deterioration detection device applied to the temperature deterioration monitoring system of electrical equipment using the temperature sensor of the optical fiber probe method according to the present invention is an optical fiber temperature sensor unit 100 and a light source unit 200 installed inside the electric equipment. ), an optical circulator 300 , a light detection unit 400 and a temperature detection unit 500 .

4 is a view showing the structure (a) of the optical fiber temperature sensor unit applied to the temperature deterioration monitoring system of electrical equipment using the temperature sensor of the optical fiber probe type according to the present invention and the characteristic curve (b) of the temperature sensitive layer.

Attached Fig. 4 (a) shows a cross-sectional view of the optical fiber temperature sensor unit, the optical fiber temperature sensor unit 100 is the optical fiber 110 and the probe 120 configured at the tip (tip) of the optical fiber 110. consists of including

The optical fiber 110 can refract light (light) traveling in a straight line to move to a desired place by refracting it in the fiber. It consists of an inner core 111 and a cladding 112 surrounding the core 111 .

The probe 120 is installed at the end of the optical fiber 110 to detect the temperature, and is installed at a position to detect the temperature (eg, inside an electrical equipment, etc.).

The probe 120 is installed at the end of the optical fiber 110 and includes a temperature sensitive layer 121 , a reflective layer 122 , and a protective layer 123 .

The temperature-sensitive layer 121 is installed at the end of the optical fiber 110 to change the wavelength and the amount of light of the incident optical signal according to the temperature change.

The material constituting the temperature-sensitive layer 121 may be made of either gallium arsenide (GaAs) or gallium phosphide (GaP).

In the present invention, gallium arsenide (GaAs) is applied to the temperature-sensitive layer 121 .

Referring to the accompanying FIG. 4 (b), in the temperature-sensitive layer 121, the light wavelength of gallium arsenide changes according to the ambient temperature, and the temperature can be detected using the changed light wavelength.

5 shows a graph of reflection, absorption, and transmission characteristics for a temperature sensitive layer.

Referring to FIG. 5 attached, based on a graph of a complex refractive index for gallium arsenide (GaAs) applied as the temperature-sensitive layer 121 for each wavelength, an extinction coefficient indicating absorption of light is 0 is shown in the optical wavelength band of 850 nm. Accordingly, it can be seen that the optical signal passes without being absorbed in a band having a wavelength of 850 nm or more.

That is, in order for the light wavelength to pass through the temperature sensitive layer 121 made of gallium arsenide (GaAs) without being absorbed, the light wavelength (optical signal) must be at least 850 nm.

Accordingly, the optical signal wavelength is 850 nm or more, but it may be configured to minimize the optical wavelength by adjusting a reflection value capable of reflecting the optical signal.

The reflective layer 122 is disposed outside the temperature-sensitive layer 121 to reflect the light source output from the temperature-sensitive layer.

A suitable material for the reflective layer 122 may be selected from silver (Ag), copper (Cu), and gold (Au).

6 is a graph showing a test of deposition thickness for reflectance of a reflective layer applied to a temperature deterioration monitoring system of an electrical equipment using a temperature sensor of an optical fiber probe type according to the present invention.

6, as a result of testing the reflectance while increasing the deposition thickness for each of silver (Ag), copper (Cu) and gold (Au), in order for the reflective layer 122 to have a reflectance of 90% or more, the It was found that the thickness of the reflective layer 122 should be deposited at least 40 nm or more.

In the above configuration, the reflective layer 122 is deposited on the temperature sensitive layer 121 .

However, the temperature-sensitive layer 121 is attached to the end of the optical fiber 110 , and a binder is required to bond the temperature-sensitive layer 121 to the optical fiber 110 .

In the present invention, a heat-dissipating adhesive for bonding the end surface of the optical fiber and the temperature-sensitive layer is used as a binder.

In this case, the optical signal may be refracted and lost by the heat dissipation adhesive.

7 is a graph showing a test of the refractive index of a heat-dissipating adhesive applied to a temperature deterioration monitoring system of an electrical equipment using a temperature sensor of an optical fiber probe type according to the present invention.

In the attached test of FIG. 7 , the thickness of the temperature-sensitive layer 121 was 650 μm and the thickness of the reflective layer 122 made of silver was 50 nm, and the reflectance was tested by adjusting the refractive index to 1.3 to 1.9.

7, it can be seen that when the optical signal wavelength is 850 nm and the refractive index of the heat dissipating adhesive is 1.6 or less, the optical signal by the reflective layer 122 is reflected by 90% or more.

Accordingly, the refractive index of the heat dissipating adhesive bonding the end surface of the optical fiber and the temperature-sensitive layer may be set in the range of 1.3 to 1.6.

On the other hand, in a state in which the probe 120 is bonded to the end of the optical fiber 110 using a heat-dissipating adhesive, the probe (temperature-sensitive layer and reflective layer) bonded to the optical fiber 110 is prevented from detaching and noise is prevented from entering. In order to do this, the outside of the probe 120 and a part of the optical fiber 110 must be protected.

The protective layer 123 (refer to FIG. 4 ) covers and protects the outside of the end portion of the optical fiber 110, the temperature-sensitive layer 121 and the reflective layer 122, so as not to be deformed in a temperature range of -200 to +260°C. It is packaged with PTFE (Polyterafluoroethlene), which is a heat- and cold-resistant material. Accordingly, due to the configuration of the protective layer 123, it is possible to detect the temperature by depositing it in the insulating oil of the transformer or to detect the temperature by installing it inside an insulating gas, etc. Gas, water, etc.) has the advantage of being able to detect the temperature.

Here, a process of manufacturing the probe 120 of the optical fiber temperature sensor unit 100 will be described.

8 is a diagram illustrating a process of manufacturing a probe applied to a temperature deterioration monitoring system of an electrical equipment using a temperature sensor of an optical fiber probe type according to the present invention.

Referring to FIG. 8 , the manufacturing process of the probe 120 is performed in the order of temperature-sensitive layer polishing, reflective layer deposition, coating layer formation, dicing, and coating layer removal steps.

The temperature-sensitive layer polishing step is a process of removing foreign substances by polishing the surface of gallium arsenide (GaAs).

The reflective layer deposition step is a process of depositing a reflective material (eg, Ag) corresponding to the reflective layer on one surface of the temperature-sensitive layer that has been polished. At this time, the thickness of the reflective layer to be deposited is at least 50 nm.

The coating layer forming step is a process of forming a coating layer on the upper surface of the reflective layer to prevent peeling of the reflective layer deposited on the temperature sensitive layer in the dicing step.

In the coating layer forming step, the coating may be performed by spin-coating the AZ5214 material to form a photo resist (PR) pattern.

The dicing step is a step of dividing a relatively wide plate (wafer) on which the coating layer forming step has been completed into predetermined sizes.

At this time, the divided size may be divided according to the diameter of the optical fiber, but since the surface to be diced in the dicing step is rough, the dicing is made to be 2 to 3 times the diameter of the core so as to sufficiently cover the core of the optical fiber.

For example, when the diameter of the optical fiber nose is 200 mu m, the size to be diced is preferably divided into a size of approximately 400 x 400 mu m or 600 x 600 mu m.

The coating layer removing step is a step of removing the coating layer coated in the coating layer forming step.

Next, a configuration for transmitting (incident) an optical signal to the optical fiber 110 of the optical fiber temperature sensor unit 100 and detecting the temperature through the reflected optical signal reflected from the optical fiber 110 will be described.

The light source unit 200 (refer to FIG. 3 ) generates and outputs an optical signal, and the generated optical signal is incident on the probe 120 through the optical fiber 110 of the optical fiber temperature sensor unit 100 .

The optical signal is configured to have a wavelength of 850 to 900 nm so that the optical signal incident to the probe 120 is not absorbed by the probe 120 and can be reflected.

Accordingly, the light source unit 200 includes an LD driver circuit for outputting an optical signal through the light source and a TEC circuit for outputting a stable optical signal output from the LD driver circuit through temperature control.

9 is a circuit diagram of an LD driver of a light source unit applied to a temperature deterioration monitoring system of an electrical equipment using a temperature sensor of an optical fiber probe type according to the present invention.

9, the LD driver circuit 210 includes a bias circuit 211 to supply stable power to maintain the optical wavelength and bandwidth of the optical signal output from the LD (Laser Diode, 213).

The bias circuit 211 determines an operating point of a voltage or current in advance, and the LD 213 maintains a wavelength and a bandwidth based on the operating point.

In addition, the LD driver circuit 210 is configured with a monitoring circuit 212 as a feedback circuit for monitoring the validity of the optical signal reflected from the probe based on the wavelength and bandwidth of the output optical signal.

On the other hand, when the LD is operated for a long time, the optical wavelength and optical power of the optical signal due to the temperature increase effect generated in the LD is changed and the function of the laser for measurement is deteriorated, which is highlighted as a cause of significant error in temperature detection. In addition, due to the temperature rise of the LD, the optical signal output from the LD is output as an elliptical optical signal, which causes astigmatism. In order to solve this problem, in the present invention, a cooling system is developed to control the temperature of the LD using a TEC (ThermoI Electric Cooler) circuit, and the optical signal emitted from the LD is changed in a circular shape to output a uniform Gaussian distribution. It is configured to prevent the change value of the wavelength and output optical power due to the temperature of the LD.

10 is a TEC circuit diagram of a light source applied to the temperature deterioration monitoring system of an electrical equipment using a temperature sensor of the optical fiber probe type according to the present invention.

10, the TEC circuit 220 is a current blocking circuit 222 for blocking the TEC (Thermol electric cooler) element 221 not to exceed the rated current and a circuit for preventing the TEC loop from oscillating. was composed That is, when the external temperature rises, the resistance of the thermistor decreases, the voltage of TH-V (temperature-voltage relationship) rises, and the output voltage of the IC increases.

Therefore, as the output voltage of the IC increases, a current flows from the (+) side of the TEC element to the (-) side of the TEC element as the temperature increases, causing a cooling action of the TEC element 221. is stabilized with

The optical circulator 300 (refer to FIG. 3 ) receives the optical signal output from the light source unit 200 through a first port and enters it into the optical fiber temperature sensor unit 100 through a second port, and the optical fiber temperature sensor unit It performs a function of receiving the optical signal reflected from (100) to the second port and outputting it to the third port.

As the optical circulator 300 may have a known configuration, a detailed description thereof will be omitted.

The photodetector 400 (refer to FIG. 3 ) receives the optical signal output from the optical circulator 300 and detects the reflected light source, and the optical signal output from the third port of the optical circulator 300, that is, The reflected optical signal reflected from the optical fiber temperature sensor unit 100 is detected.

11 is a circuit diagram of a photodetector applied to a temperature deterioration monitoring system for electrical equipment using a temperature sensor of an optical fiber probe type according to the present invention.

11 , the photodetector 400 includes a photodetector 410 that receives a reflected optical signal output from the optical circulator 300 , an amplifier circuit 420 , and a noise reduction circuit 430 . is composed by

The photodetector 410 is a diode that receives a reflected light signal, and may be formed of a Si-based photodiode having a band of light wavelength of 850 nm or more.

12 is a graph showing the performance evaluation graph for the temperature measurement and resolution of the photodetector applied to the temperature deterioration monitoring system of electrical equipment using the temperature sensor of the optical fiber probe method according to the present invention.

Attached Fig. 12 (a) is a performance evaluation graph of temperature measurement and resolution using a photodetector having a center wavelength of 890 nm and a bandwidth of 70 nm, and (b) of FIG. 12 is a photodetecting device having a center wavelength of 915 nm and a bandwidth of 85 nm. It is a performance evaluation graph of temperature measurement and resolution.

Referring to (a) of FIG. 12 , in the case of a photodetector having a center wavelength of 890 nm and a bandwidth of 70 nm, a non-linear section exists and temperature detection is ambiguous in a low temperature (around -30 ° C) section and a high temperature (110 ~ 150 ° C) section. was derived That is, it can be seen that the measurement resolution is lowered in the low-temperature section and the high-temperature section.

On the other hand, referring to (b) of FIG. 12 , in the case of a photodetector having a central wavelength of 915 nm and a bandwidth of 85 nm, it can be seen that the overall linear shape is shown and the overall measurement resolution is excellent from low to high temperature.

Accordingly, the photodetector 410 may be formed of a photodiode having a center wavelength of 915 nm and a bandwidth of 85 nm.

The amplifying circuit 420 converts the current signal of the optical signal obtained by the photodetector 410 into a voltage signal and amplifies it.

The reflected optical signal received by the photodetector 410 is received as a signal in the form of a current, and the current signal is converted into a voltage signal in the amplifier circuit 420 and amplified.

The photodetector 400 shown in FIG. 11 is a circuit diagram for receiving two reflected optical signals to amplify and remove noise. When a voltage input to the (+) terminal of the amplifier is continuously connected, a plurality of reflected optical signals It is possible to configure the photodetector 400 that can receive the .

In addition, in the amplifier circuit 420, the amplifier, the resistor R301, and the capacitor C300 are connected in parallel to prevent a phase shift of the feedback signal.

The noise reduction circuit 430 removes noise from the voltage signal amplified by the amplifier circuit 420 .

The temperature detector 500 detects a temperature based on the reflected light signal detected by the photodetector 400 .

The temperature detection unit 500 detects the temperature using the principle that the optical signal incident to the temperature sensitive layer 121 is reflected in response to a change in temperature, and the optical wavelength is shifted during the incident and reflected process to change the characteristics. .

The monitoring device 20 (refer to FIGS. 1 and 2 ) displays the temperature of the corresponding electrical equipment based on the detected temperature transmitted from the deterioration detection device 10 and outputs an abnormal signal when it is determined that the temperature is abnormal.

In this case, the monitoring device 20 may be configured to monitor the temperature or degradation of the entire power facility in connection with a plurality of degradation detection devices 10 in a centralized manner.

That is, the monitoring device 20 receives the temperature transmitted from the deterioration detection device 10 and analyzes the received temperature to determine whether there is an abnormality in the electrical equipment. The monitoring device 20 monitors the temperature of the electrical equipment, compares it with a reference temperature or obtains a temperature rise value to determine whether there is an abnormality in the whole or in each equipment configuration.

In addition, the monitoring device 20 displays the measured internal or facility temperature as an image on the display, or when detecting the presence or absence of an abnormality, notifies the manager of the detected matter as an alarm.

That is, the monitoring device 20 makes a diagnosis by inferring the deterioration state inside the electrical equipment based on the internal temperature detected by the deterioration detection device 10 and the temperature of each equipment, and the diagnosed deterioration state information in the housing Controls the internal state of the housing or generates an alarm signal.

According to the present invention, it is possible to detect deterioration and abnormality in temperature by applying it to power equipment such as switchboards, and it is difficult to install a temperature sensor in a gas insulated switchgear (GIS) or transformer insulation oil, dust such as winding It has the advantage of being able to detect and monitor the temperature in adverse conditions such as , moisture and gas.

In addition, since the temperature is detected using the optical signal and the reflected optical signal in the process of measuring the temperature, there is an advantage in that the temperature measurement does not accompany the current, thereby preventing the explosion caused by the temperature measurement.

In the above, a preferred embodiment of the temperature deterioration monitoring system for electrical equipment using the temperature sensor of the optical fiber probe type according to the present invention has been described, but the present invention is not limited thereto, and the claims and description of the invention, It is possible to carry out various modifications within the scope, and this also falls within the scope of the present invention.

1: Switchgear 2: Transformer
10: deterioration detection device 20: monitoring device
100: optical fiber temperature sensor unit 110: optical fiber
111: core 112: clad
120: probe 121: temperature sensitive layer
122: reflective layer 123: protective layer
200: light source unit 300: optical circulator
400: light detection unit 500: temperature detection unit

Claims (7)

Comprising a deterioration detection device for detecting the internal temperature of the electrical equipment and the electrical equipment, and a monitoring device for monitoring based on the temperature detected by the deterioration detection device,
The deterioration detection device,
an optical fiber having a core and a cladding layer surrounding the core, and an optical fiber temperature sensor unit including a probe configured at an end of the optical fiber;
a light source for outputting an optical signal;
The optical signal output from the light source unit is received through a first port, is incident on the optical fiber temperature sensor unit through a second port, and the optical signal reflected from the optical fiber temperature sensor unit is received through the second port and is transmitted to a third port. an optical circulator outputting;
a photodetector configured to receive an optical signal output from the optical circulator and detect a reflected optical signal; and
a temperature detection unit configured to detect a temperature based on the reflected light signal detected by the light detection unit;
including,
The probe is
a temperature-sensitive layer installed at the end of the optical fiber and varying the wavelength and amount of light according to temperature change;
a reflective layer disposed outside the temperature-sensitive layer to reflect the light source output from the temperature-sensitive layer; and
a protective layer surrounding the outside of the optical fiber, the temperature sensitive layer and the reflective layer;
includes,
The light source unit,
an LD driver circuit outputting an optical signal through a light source; and
a TEC circuit for outputting an optical signal output from the LD driver circuit through temperature control;
including,
The LD driver circuit comprises:
a bias circuit for supplying power to maintain an optical wavelength and bandwidth of an optical signal output from a laser diode (LD); and
a monitoring circuit as a feedback circuit for monitoring the effectiveness of the optical signal reflected from the probe;
consists of,
The TEC circuit is
A current blocking circuit for controlling the temperature of the LD using a TEC (ThermoI Electric Cooler) device, but blocking the TEC device from exceeding the rated current;
includes,
The photodetector,
photodetector;
an amplifier circuit in which an amplifier, a resistor and a capacitor are connected in parallel to convert and amplify the current signal of the reflected optical signal obtained from the photodetector into a voltage signal; and
a noise reduction circuit for removing noise from the voltage signal amplified by the amplifier circuit;
including,
The photodetector is
A temperature deterioration monitoring system for electrical equipment using a temperature sensor of the optical fiber probe method, characterized in that the central wavelength is 915 nm and the bandwidth is 85 nm.
delete The method according to claim 1,
The probe is
After the surface of the temperature-sensitive layer is polished to remove foreign substances, and a reflective material corresponding to the reflective layer is deposited on one surface of the temperature-sensitive layer from which the foreign substances are removed, to prevent peeling of the reflective layer deposited on the temperature-sensitive layer After forming a coating layer on the upper surface of the reflective layer, dividing it into predetermined sizes, and removing the formed coating layer.
The method according to claim 1,
The temperature sensitive layer,
A temperature degradation monitoring system for electrical equipment using a temperature sensor of an optical fiber probe method, characterized in that it is gallium arsenide (GaAs).
The method according to claim 1,
The temperature deterioration monitoring system of electrical equipment using a temperature sensor of the optical fiber probe method, characterized in that the refractive index of the heat-dissipating adhesive bonding the end face of the optical fiber and the temperature-sensitive layer is in the range of 1.3 to 1.6. delete delete

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