CN218444213U - Optical fiber temperature detection device and power transmission line temperature detection system - Google Patents
Optical fiber temperature detection device and power transmission line temperature detection system Download PDFInfo
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- CN218444213U CN218444213U CN202222105304.7U CN202222105304U CN218444213U CN 218444213 U CN218444213 U CN 218444213U CN 202222105304 U CN202222105304 U CN 202222105304U CN 218444213 U CN218444213 U CN 218444213U
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Abstract
The application discloses optic fibre temperature-detecting device and transmission line temperature detecting system. The optical fiber temperature detection device includes: the continuous optical laser is used for emitting continuous optical signals, a first input end of a first optical splitter is connected with the continuous optical laser, an optical pulse modulator is connected with a first output end, a first port of an optical circulator is connected with the optical pulse modulator, the second optical splitter comprises a second input end and at least two output ports, the second input end is connected with the second port, an optical modulation module comprises at least two optical modulators, each optical modulator is connected with a corresponding output port, each optical modulator is used for connecting a corresponding detection optical fiber, an optical frequency shift modulator is connected with the second output end, a digital coherent optical receiver is respectively connected with the optical frequency shift modulator and a third port, and a sensing signal processor is connected with a digital coherent optical receiver. The detection of the multipath temperature signals can be completed by only using one digital coherent optical receiver, so that the cost of temperature detection is reduced.
Description
Technical Field
The application relates to the technical field of temperature detection, in particular to an optical fiber temperature detection device and a transmission line temperature detection system.
Background
With the development of power systems, the magnitude of transmission voltage and transmission current is greatly improved, so that the temperature change along the power transmission line needs to be measured quickly and accurately to ensure the safe and stable operation of the power transmission line. An optical fiber sensing device for online temperature detection based on the optical fiber Brillouin effect is provided in the related art, but when the optical fiber sensing device is used for detecting the temperature of a plurality of power transmission lines, a digital coherent optical receiver needs to be arranged for each power transmission line, so that the cost of temperature detection is high.
SUMMERY OF THE UTILITY MODEL
The present application is directed to solving at least one of the problems in the prior art. Therefore, the application provides an optical fiber temperature detection device which can perform multi-path temperature detection under the condition that only one digital coherent optical receiver is arranged, and the cost of temperature detection is reduced.
The application also provides a transmission line temperature detection system with the optical fiber temperature detection device.
The optical fiber temperature detection device according to the embodiment of the first aspect of the application comprises: a continuous light laser for emitting a continuous light signal; the first optical splitter comprises a first input end, a first output end and a second output end, and the first input end is connected with the continuous light laser; an optical pulse modulator connected to the first output terminal; the optical circulator comprises a first port, a second port and a third port, and the first port is connected with the optical pulse modulator; a second optical splitter comprising a second input and at least two output ports, the second input being connected to the second port; the optical modulation module comprises at least two optical modulators, each optical modulator is connected with the corresponding output port, and each optical modulator is used for connecting the corresponding detection optical fiber; the optical frequency shift modulator is connected with the second output end; a digital coherent optical receiver, which is connected to the optical frequency shift modulator and the third port, respectively; and the sensing signal processor is connected with the digital coherent light receiver.
According to some embodiments of the present application, the continuous-light laser is a narrow-linewidth fiber laser.
According to some embodiments of the application, the first optical splitter is a equipartition optical splitter.
According to some embodiments of the application, the optical pulse modulator comprises: the pulse driving signal generator is connected with the optical amplitude modulator.
According to some embodiments of the application, the optical amplitude modulator is an electro-optic modulator or an acousto-optic modulator.
According to some embodiments of the present application, the optical frequency shift modulator is configured to shift an input optical signal to a low frequency direction.
According to some embodiments of the present application, the second optical splitter comprises a first output port and a second output port, and the optical modulation module comprises a first optical modulator and a second optical modulator, the first output port is connected to the first optical modulator, and the second output port is connected to the second optical modulator.
The power transmission line temperature detection system according to the second aspect of the present application includes the optical fiber temperature detection device according to the first aspect of the present application.
According to some embodiments of the application, the transmission line temperature detection system further comprises: the optical fiber tube is internally provided with a detection optical fiber which is connected with the optical fiber temperature detection device, and the optical fiber tube is arranged in contact with the power transmission line.
According to some embodiments of the present application, a heat transfer medium is filled between the fiber tube and the transmission line.
According to the optical fiber temperature detection device and the power transmission line temperature detection system, the optical fiber temperature detection device and the power transmission line temperature detection system at least have the following beneficial effects: the optical signals output by at least two output ports of the second optical splitter are modulated by at least two corresponding optical modulators and then are respectively input into corresponding detection optical fibers for temperature detection, a digital coherent optical receiver is used for processing the multi-path optical signals, and a sensing signal processor is used for analyzing and obtaining multi-path temperature detection information. The detection of the multipath temperature signals can be completed by only using one digital coherent optical receiver, so that the cost of temperature detection is reduced.
Additional aspects and advantages of the present application will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the present application.
Drawings
The present application is further described with reference to the following figures and examples, in which:
FIG. 1 is a schematic view of an optical fiber temperature detecting device according to an embodiment of the present application;
FIG. 2 is a schematic diagram of an optical pulse modulator according to an embodiment of the present application;
fig. 3 is a schematic diagram of a second optical splitter and an optical modulation module according to an embodiment of the present application;
fig. 4 is a schematic diagram of a power transmission line layout according to an embodiment of the present application.
Reference numerals are as follows:
a continuous optical laser 100, a first optical splitter 200, an optical pulse modulator 300, and an optical circulator 400;
a second optical splitter 500, an optical modulation module 600, an optical frequency shift modulator 700, and a digital coherent optical receiver 800;
a sensing signal processor 900, a first input end 210, a first output end 220, a second output end 230;
a first port 410, a second port 420, a third port 430, a pulse drive signal generator 310;
an optical amplitude modulator 320, a second input 510, a first output port 520, a second output port 530;
a first optical modulator 610, a second optical modulator 620, a fiber tube 101, and a detection fiber 102;
a power line 103 and a heat transfer medium 104.
Detailed Description
Reference will now be made in detail to embodiments of the present application, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are exemplary only for the purpose of explaining the present application and are not to be construed as limiting the present application.
In the description of the present application, it is to be understood that the positional descriptions, such as the directions of up, down, front, rear, left, right, etc., referred to herein are based on the directions or positional relationships shown in the drawings, and are only for convenience of description and simplification of description, and do not indicate or imply that the referred device or element must have a specific direction, be constructed and operated in a specific direction, and thus, should not be construed as limiting the present application.
In the description of the present application, the meaning of a plurality is one or more, the meaning of a plurality is two or more, and the above, below, exceeding, etc. are understood as excluding the present number, and the above, below, within, etc. are understood as including the present number. If there is a description of first and second for the purpose of distinguishing technical features only, this is not to be understood as indicating or implying a relative importance or implicitly indicating the number of technical features indicated or implicitly indicating the precedence of technical features indicated.
In the description of the present application, unless otherwise expressly limited, terms such as set, mounted, connected and the like should be construed broadly, and those skilled in the art can reasonably determine the specific meaning of the terms in the present application by combining the detailed contents of the technical solutions.
Some embodiments, referring to fig. 1, the present application provides an optical fiber temperature detection apparatus, including: the optical fiber sensor comprises a continuous light laser 100, a first optical splitter 200, an optical pulse modulator 300, an optical circulator 400, a second optical splitter 500, an optical modulation module 600, an optical frequency shift modulator 700, a digital coherent optical receiver 800 and a sensing signal processor 900, wherein the continuous light laser 100 is used for emitting continuous light signals, the first optical splitter 200 comprises a first input end 210, a first output end 220 and a second output end 230, the first input end 210 is connected with the continuous light laser 100, the optical pulse modulator 300 is connected with the first output end 220, the optical circulator 400 comprises a first port 410, a second port 420 and a third port 430, the first port 410 is connected with the optical pulse modulator 300, the second optical splitter 500 comprises a second input end 510 and at least two output ports, the second input end 510 is connected with the second port 420, the optical module 600 comprises at least two optical modulators, each optical modulator is connected with a corresponding output port, each optical modulator is used for connecting a corresponding detection optical fiber, the optical frequency shift modulator 700 is connected with the second output end 230, the digital coherent optical receiver 800 is respectively connected with the frequency shift modulator 700 and the digital coherent optical signal processor 900.
In a specific example, the continuous light laser 100 is a main light source of a fiber temperature detection device, and is used for emitting a continuous light signal without any modulation. Because the detection principle of the optical fiber temperature detection device in the embodiment of the present application is based on brillouin scattering, the emitted light power of the continuous optical laser 100 is much higher than the brillouin scattering threshold of the detection optical fiber, so as to sufficiently excite the brillouin scattering effect in the detection optical fiber. The continuous-light signal emitted by the continuous-light laser 100 is sent to a first input 210 of the first optical splitter 200.
The first optical splitter 200 of the embodiment of the present application is a 1 × 2 optical splitter, i.e., has one input and two outputs. After receiving the continuous optical signal, the first input end 210 of the first optical splitter 200 splits the continuous optical signal into a first optical signal and a second optical signal according to a preset ratio, and outputs the first optical signal and the second optical signal through the first output end 220 and the second output end 230, respectively. The first optical signal is output to the optical pulse modulator 300 through the first output terminal 220, and the second optical signal is output to the optical frequency shift modulator 700 through the second output terminal 230.
The optical pulse modulator 300 is configured to receive the first optical signal and perform amplitude modulation on the first optical signal to obtain a periodic optical pulse signal. For example, the period of the periodic optical pulse signal generated by the optical pulse modulator 300 may be several kilohertz to several ten kilohertz, and the pulse width may be several hundred nanoseconds to several tens of microseconds. The periodic optical pulse signal generated by the optical pulse modulator 300 is for transmission to the first port 410 of the optical circulator 400.
The optical circulator 400 has a first port 410, a second port 420, and a third port 430. Wherein, the optical signal inputted from the first port 410 can only be transmitted to the second port 420 in one direction, and the optical signal can be isolated when transmitted in the reverse direction (at least 30dB optical isolation). The optical signal inputted from the second port 420 can only be transmitted to the third port 430 in one direction, and is isolated (optical isolation of at least 30 dB) when it is transmitted in the reverse direction. Therefore, when the first port 410 of the optical circulator 400 receives the periodic optical pulse signal from the optical pulse modulator 300, the optical pulse signal is transmitted to the second input terminal 510 of the second optical splitter 500 through the second port 420 as brillouin pump light.
The second optical splitter 500 according to the embodiment of the present application is a 1 × N optical splitter, where N is greater than or equal to 2. I.e. the second optical splitter 500 has one input and at least two outputs. The second optical splitter 500 is configured to split the optical pulse signal and transmit the split optical pulse signal to the optical modulation module 600.
The optical modulation module 600 includes at least two optical modulators, and the optical modulators are configured to be connected to the output end of the second optical splitter 500, and modulate the split optical pulse signals, and the modulated optical signals are transmitted to the detection optical fiber. The optical modulator is used for loading code modulation with orthogonal characteristic (the result of correlation operation between codes with orthogonal characteristic is 0) on an optical pulse signal entering the detection optical fiber. During modulation, a relatively small modulation depth, for example, perturbation intensity modulation with a modulation depth of 10%, may be adopted, and this coded modulation will be used as a coded label in the subsequent sensing signal demodulation process, and the coded label is used to distinguish the sensing signals reflected by different detection optical fibers. For example, code 1 corresponds to one detection fiber and code 2 corresponds to another detection fiber.
When the optical pulse signal modulated by the optical modulator is transmitted along the detection optical fiber, a brillouin scattering sensing signal is excited at each point of the optical fiber, the brillouin scattering sensing signal is opposite to the transmission direction of the periodic optical pulse signal input into the detection optical fiber and is called a brillouin scattering reflection signal, and the intensity of the reflection signal is related to the temperature at the point of the detection optical fiber. The brillouin scattering reflection signal serving as the optical sensing signal to be measured returns to the second port 420 of the optical circulator 400 after passing through the second optical splitter 500, is transmitted to the third port 430 of the optical circulator 400, and is then transmitted to the digital coherent optical receiver 800 through the third port 430.
The optical frequency shift modulator 700 is configured to shift an optical frequency of the second optical signal transmitted by the first optical splitter 200 according to a preset value, and the optical signal that is frequency-shifted by the optical frequency shift modulator 700 is transmitted to the digital coherent optical receiver 800 as local oscillation light. As a specific example, for a standard single mode fiber, the preset value in frequency shift may be set to 11GHz.
The digital coherent optical receiver 800 is configured to receive an optical sensing signal to be detected, and perform coherent reception on the optical sensing signal to be detected based on local oscillator light transmitted from the optical frequency shift modulator 700 to obtain a sensing electrical signal. After the optical sensing signal to be detected is subjected to frequency mixing with the local oscillator light and balanced light detection in the digital coherent optical receiver 800, I and Q signals of the optical sensing signal to be detected in two light polarization directions X/Y can be obtained, so that a complex expressed brillouin sensing electrical signal of the optical sensing signal to be detected can be completely reconstructed in a digital domain. Finally, the digital coherent optical receiver 800 transmits the digital domain sensing electrical signal to be measured to the sensing signal processor 900.
The sensing signal processor 900 is configured to receive the sensing electrical signal transmitted by the digital coherent optical receiver 800, and extract a frequency shift amount of the brillouin scattering reflected signal through a frequency locking tracking algorithm. It should be noted that, at this time, the obtained sensing electrical signal includes sensing signals reflected by multiple detection optical fibers, and in order to further distinguish the sensing signals of different detection optical fibers, it is necessary to perform coding correlation operation by using codes corresponding to the detection optical fibers and the sensing signals, so that the sensing signals can be decomposed into temperature distribution curves of multiple optical fiber lines corresponding to different detection optical fibers, thereby completing detection of multiple temperature signals.
The optical fiber temperature detection device provided by the embodiment of the application can distinguish the reflection signals of different detection optical fibers by arranging the light modulation module 600, the digital coherent light receiver and the sensing signal processor 900, can complete the detection of multi-path temperature signals by only using one digital coherent light receiver, and reduces the cost of temperature detection.
In some embodiments, continuous-light laser 100 is a narrow-linewidth fiber laser. Continuous optical signals output by the narrow-linewidth optical fiber laser have extremely high time coherence and extremely low phase noise, high power density is easily formed in the optical fiber, and Brillouin scattering sensing signals can be better excited.
In some embodiments, the first optical splitter 200 is a equipartition optical splitter, that is, the splitting ratio of the first optical splitter 200 is 50% to 50%, and the optical power of the first optical signal and the optical power of the second optical signal obtained by splitting at the first optical splitter 200 are the same. It will be appreciated that in some other embodiments, the splitting ratio of the first optical splitter 200 may be varied according to the number of detection fibers.
Some embodiments, referring to fig. 2, the optical pulse modulator 300 includes: a pulse driving signal generator 310 and an optical amplitude modulator 320, wherein the optical amplitude modulator 320 is connected to the first output terminal 220, and the pulse driving signal generator 310 is connected to the optical amplitude modulator 320. The pulse drive signal generator 310 is configured to generate a periodic electrical pulse drive signal, and the optical amplitude modulator 320 is configured to modulate the received electrical pulse drive signal on a first optical signal to generate a periodic optical pulse signal.
In some embodiments, the optical amplitude modulator 320 is an electro-optic modulator or an acousto-optic modulator.
In some embodiments, the optical frequency shift modulator 700 is configured to shift the frequency of an incoming optical signal to a low frequency.
Some embodiments, referring to fig. 3, the second optical splitter 500 includes a first output port 520 and a second output port 530, the optical modulation module 600 includes a first optical modulator 610 and a second optical modulator 620, the first output port 520 is connected to the first optical modulator 610, and the second output port 530 is connected to the second optical modulator 620. The optical fiber temperature detection device is used for connecting two paths of detection optical fibers and respectively detecting the temperature information of the two paths of detection optical fibers.
In some embodiments, the present application further provides a power transmission line temperature detection system, which includes the optical fiber temperature detection device in the above embodiments. The detection optical fiber is placed in the power transmission line and used for detecting temperature change of the power transmission circuit. The optical fiber temperature detection device is arranged in the main machine room and is used for connecting detection optical fibers arranged in the power transmission line.
Some embodiments, referring to fig. 4, the power transmission line temperature detection system further includes: the optical fiber tube 101, the optical fiber tube 101 is internally provided with a detection optical fiber 102, the detection optical fiber 102 is connected with an optical fiber temperature detection device, and the optical fiber tube 101 is arranged in contact with a transmission line 103. Specifically, the power transmission line according to the embodiment of the present application is a three-phase power transmission line, three power transmission lines 103 are disposed in the circuit pipe protective sheath, and the optical fiber tube 101 is in close contact with the power transmission lines 103, so as to detect temperature changes of the power transmission lines 103 more directly. In some other embodiments, the location of the detection fiber 102 can be selected based on the particular arrangement of the power line 103.
In some embodiments, a heat conducting medium 104 is filled between the fiber tube 101 and the power line 103. Through filling heat-conducting medium 104 in the circuit pipeline protective sheath, can be more timely with the heat conduction to the fiber tube 101 of power transmission line 103 for the power transmission line 103 temperature that optical fiber temperature detection device detected is more timely.
In the description of the present application, reference to the description of "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples", etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present application. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.
The embodiments of the present application have been described in detail with reference to the drawings, but the present application is not limited to the embodiments, and various changes can be made within the knowledge of those skilled in the art without departing from the gist of the present application. Furthermore, the embodiments and features of the embodiments of the present application may be combined with each other without conflict.
Claims (10)
1. Optical fiber temperature detection device, its characterized in that includes:
a continuum optical laser for emitting a continuum optical signal;
the first optical splitter comprises a first input end, a first output end and a second output end, and the first input end is connected with the continuous light laser;
an optical pulse modulator connected to the first output terminal;
the optical circulator comprises a first port, a second port and a third port, and the first port is connected with the optical pulse modulator;
a second optical splitter comprising a second input and at least two output ports, the second input being connected to the second port;
the optical modulation module comprises at least two optical modulators, each optical modulator is connected with the corresponding output port, and each optical modulator is used for connecting the corresponding detection optical fiber;
the optical frequency shift modulator is connected with the second output end;
a digital coherent optical receiver, which is connected to the optical frequency shift modulator and the third port, respectively;
and the sensing signal processor is connected with the digital coherent light receiver.
2. The fiber temperature sensing device of claim 1, wherein the continuous light laser is a narrow linewidth fiber laser.
3. The optical fiber temperature detection device according to claim 1, wherein the first optical splitter is a equipartition optical splitter.
4. The optical fiber temperature detection apparatus according to claim 1, wherein the optical pulse modulator comprises: the pulse driving signal generator is connected with the optical amplitude modulator.
5. The optical fiber temperature detection device according to claim 4, wherein the optical amplitude modulator is an electro-optic modulator or an acousto-optic modulator.
6. The optical fiber temperature detecting device according to claim 1, wherein the optical frequency shift modulator is configured to shift the frequency of the input optical signal to a low frequency direction.
7. The optical fiber temperature detection device according to any one of claims 1 to 6, wherein the second optical splitter comprises a first output port and a second output port, the optical modulation module comprises a first optical modulator and a second optical modulator, the first output port is connected to the first optical modulator, and the second output port is connected to the second optical modulator.
8. Transmission line temperature detection system, characterized in that it comprises an optical fiber temperature detection device according to any one of claims 1 to 7.
9. The power transmission line temperature detection system of claim 8, further comprising:
the optical fiber tube is internally provided with a detection optical fiber which is connected with the optical fiber temperature detection device, and the optical fiber tube is arranged in contact with the power transmission line.
10. The power transmission line temperature detection system of claim 9, wherein a heat transfer medium is filled between the optical fiber tube and the power transmission line.
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| CN202222105304.7U CN218444213U (en) | 2022-08-10 | 2022-08-10 | Optical fiber temperature detection device and power transmission line temperature detection system |
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| CN202222105304.7U CN218444213U (en) | 2022-08-10 | 2022-08-10 | Optical fiber temperature detection device and power transmission line temperature detection system |
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