CN110793665A - Submarine cable all-fiber temperature online monitoring system and monitoring method - Google Patents
Submarine cable all-fiber temperature online monitoring system and monitoring method Download PDFInfo
- Publication number
- CN110793665A CN110793665A CN201911175481.9A CN201911175481A CN110793665A CN 110793665 A CN110793665 A CN 110793665A CN 201911175481 A CN201911175481 A CN 201911175481A CN 110793665 A CN110793665 A CN 110793665A
- Authority
- CN
- China
- Prior art keywords
- submarine cable
- temperature
- conductor
- fiber
- cable
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01K—MEASURING TEMPERATURE; MEASURING QUANTITY OF HEAT; THERMALLY-SENSITIVE ELEMENTS NOT OTHERWISE PROVIDED FOR
- G01K11/00—Measuring temperature based upon physical or chemical changes not covered by groups G01K3/00, G01K5/00, G01K7/00 or G01K9/00
- G01K11/32—Measuring temperature based upon physical or chemical changes not covered by groups G01K3/00, G01K5/00, G01K7/00 or G01K9/00 using changes in transmittance, scattering or luminescence in optical fibres
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R15/00—Details of measuring arrangements of the types provided for in groups G01R17/00 - G01R29/00, G01R33/00 - G01R33/26 or G01R35/00
- G01R15/14—Adaptations providing voltage or current isolation, e.g. for high-voltage or high-current networks
- G01R15/24—Adaptations providing voltage or current isolation, e.g. for high-voltage or high-current networks using light-modulating devices
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Measuring Temperature Or Quantity Of Heat (AREA)
Abstract
The invention discloses a submarine cable all-fiber temperature online monitoring system and a submarine cable all-fiber temperature online monitoring method, wherein the submarine cable all-fiber temperature online monitoring system comprises a fiber current transformer, a fiber current transformer and a monitoring device, wherein the fiber current transformer is arranged at a submarine cable terminal position to measure and acquire current flowing through a submarine cable conductor; the distributed optical fiber sensor is used for monitoring the temperature distribution on the surface of the submarine cable in real time; and the online monitoring terminal is used for receiving the current parameters obtained by the optical fiber current transformer and the real-time temperature distribution parameters on the surface of the submarine cable obtained by the distributed optical fiber sensor, and displaying and outputting the real-time temperature distribution condition of the submarine cable conductor according to the two parameters. According to the invention, the online monitoring of the submarine cable temperature is realized by adopting an all-fiber form, so that the problem that the traditional transformer substation current transformer cannot accurately measure the short plate of the current flowing through the submarine cable conductor is avoided, and more accurate data is provided for the calculation of the submarine cable conductor temperature.
Description
Technical Field
The invention relates to the technical field of monitoring, in particular to a submarine cable all-fiber temperature online monitoring system and a submarine cable all-fiber temperature online monitoring method.
Background
Submarine cables are laid on the seabed and are mechanically protected by a landfill dam, a riprap dam, a cast iron sleeve and the like, so that the operating state of the submarine cables cannot be known by a conventional maintenance patrol means. When the submarine cable is damaged or has insulation fault, a fault point can generate heat, so that the monitoring of the temperature along the submarine cable is very important for mastering the running state of the submarine cable.
Typically, submarine cable conductor temperature monitoring is divided into two steps: calculating the surface temperature of the submarine cable through the binding optical fiber or the internal composite optical fiber of the submarine cable; and (3) building a submarine cable heating model, calculating joule heat through the current flowing through the conductor, and calculating the temperature of the conductor by combining the surface temperature according to the heat conduction model. Therefore, in the process of online monitoring the temperature of the submarine cable, the acquisition of the current flowing through the conductor of the submarine cable is very important. Conventionally, the current is obtained by current transformers on both sides of the submarine cable, but since the submarine cable terminal is close to the sea, the current transformers are usually installed at a substation at a certain distance from the terminal station, and the measured current includes the capacitance current of the overhead line, and the like. Taking the Hainan networking engineering as an example, the submarine cable crosses the Qinhua, Hainan side line current transformer is installed in a Fushan transformer substation which is 14km away from a terminal station; the current transformer of the wide east line is arranged in a slowly smelling switch station which is about 14km away from the terminal station; in addition, the transformer substations/switch stations on two sides are provided with parallel reactors for compensating the line capacitors, so that the currents measured by the current transformers on the two sides comprise capacitive currents of the lines and inductive currents of the parallel reactors, which cannot accurately represent the current flowing through the submarine cable conductor, and the submarine cable conductor current calculated and monitored by using the measured currents is not accurate any more. In addition, the conventional current transformer has some risks such as short circuit, open circuit, explosion, discharge and the like.
Disclosure of Invention
The invention provides a submarine cable all-fiber temperature online monitoring system and a submarine cable all-fiber temperature online monitoring method, aiming at solving the technical problems that the conventional submarine cable temperature monitoring is inaccurate and has potential safety hazards.
In order to achieve the purpose, the technical scheme of the invention is as follows:
in a first aspect, an embodiment of the present invention provides an all-fiber temperature online monitoring system for an undersea cable, where the undersea cable is bundled with an optical cable or internally compounded, and the monitoring system includes:
a fiber optic current transformer for installation at a submarine cable termination location for measuring and acquiring current flowing through a submarine cable conductor;
the distributed optical fiber sensor is used for monitoring the temperature distribution on the surface of the submarine cable in real time;
and the online monitoring terminal is used for receiving the current parameters obtained by the optical fiber current transformer and the real-time temperature distribution parameters on the surface of the submarine cable obtained by the distributed optical fiber sensor, and displaying and outputting the real-time temperature distribution condition of the submarine cable conductor according to the two parameters.
In a second aspect, an embodiment of the present invention provides an all-fiber temperature online monitoring method for an undersea cable, where the undersea cable is bundled with an optical cable or internally compounded with an optical fiber, and the method includes:
installing an optical fiber sensing ring of the optical fiber current transformer at a flange at the lower part of a submarine cable terminal, wherein the armor and the lead sheath of the submarine cable are stripped at the installation position before installation;
monitoring the real-time temperature distribution on the surface of the submarine cable by using a distributed optical fiber sensor to the bundled optical cable or the composite optical fiber of the submarine cable;
receiving current parameters obtained by measuring by the optical fiber current transformer and real-time temperature distribution parameters on the surface of the submarine cable obtained by monitoring by the distributed optical fiber sensor through the online monitoring terminal, and displaying and outputting the real-time temperature distribution condition of the submarine cable conductor according to the two parameters
Compared with the prior art, the invention has the beneficial effects that:
according to the invention, the online monitoring of the submarine cable temperature is realized by adopting an all-fiber form, so that the problem that the traditional transformer substation current transformer cannot accurately measure the short plate of the current flowing through the submarine cable conductor is avoided, and more accurate data is provided for the calculation of the submarine cable conductor temperature; the online monitoring is carried out in an all-fiber mode, so that direct contact with a primary high-voltage and large-current part is avoided, accidents such as electric shock and the like are avoided, short-circuit and open-circuit faults are avoided, and accidents such as discharge and explosion are avoided; the online monitoring is carried out in an all-fiber mode, so that the equipment is more miniaturized, and the installation and maintenance are more economical and more economical; maintenance of the equipment can be avoided.
The invention comprehensively applies the distributed optical fiber sensing technology, the optical fiber current transformer technology and the submarine cable heat conduction model principle to realize the submarine cable temperature on-line monitoring in the all-optical fiber form. By adopting the monitoring principle, the current error of the traditional monitoring mode is avoided, the temperature of the submarine cable conductor is more accurately monitored, and the running state of the submarine cable is more accurately evaluated. In addition, the equipment scale is smaller, the installation and later-period maintenance are more convenient, the cost is greatly shortened, and the maintenance work of oil-filled and gas-filled equipment is avoided.
Drawings
Fig. 1 is a schematic composition diagram of an all-fiber temperature online monitoring system for a submarine cable according to an embodiment of the present invention;
in the figure: 1. an optical fiber current transformer; 2. a distributed optical fiber sensor; 3. an online monitoring terminal; 11. an optical fiber sensing ring; 100. a submarine cable; 101. an optical cable; 102. binding tapes; 1001. a submarine cable termination.
Detailed Description
The present invention will be described in further detail with reference to the accompanying drawings and detailed description.
Example (b):
as shown in fig. 1, the existing submarine cable 100 is bound with optical cables 101 or optical fibers are compounded therein, and in this embodiment, the submarine cable 100 is bound with the optical cables 101 by means of a binding tape 102. The submarine cable all-fiber temperature online monitoring system provided by the embodiment mainly comprises three parts, namely, an optical fiber current transformer 1, a distributed optical fiber sensor 2 and an online monitoring terminal 3.
The optical fiber current transformer 1 is used for being installed at a position of a submarine cable terminal 1001 to measure and acquire current flowing through a submarine cable conductor; the distributed optical fiber sensor 2 is used for monitoring the temperature distribution on the surface of the submarine cable in real time; the online monitoring terminal 3 is used for receiving current parameters obtained by the optical fiber current transformer 1 and real-time temperature distribution parameters of the surface of the submarine cable obtained by the distributed optical fiber sensor 2, and displaying and outputting the real-time temperature distribution condition of the submarine cable conductor according to the two parameters.
Therefore, the system realizes the online monitoring of the submarine cable temperature by adopting the all-fiber form, avoids the problem that the traditional transformer substation current transformer cannot accurately measure the short plate of the current flowing through the submarine cable conductor, and provides more accurate data for the calculation of the submarine cable conductor temperature; the online monitoring is carried out in an all-fiber mode, so that direct contact with a primary high-voltage and large-current part is avoided, accidents such as electric shock and the like are avoided, short-circuit and open-circuit faults are avoided, and accidents such as discharge and explosion are avoided; the online monitoring is carried out in an all-fiber mode, so that the equipment is more miniaturized, and the installation and maintenance are more economical and more economical; the maintenance of the equipment can be avoided, and the complex maintenance work of the conventional oil-filled and gas-filled equipment can be avoided.
Optionally, the fiber optic current transformer 1 is installed at the flange of the lower part of the submarine cable terminal 1001 by the fiber optic sensing ring 11, where the sheath and lead sheath of the submarine cable 100 are stripped off, so as to avoid the interference of the induced power of the external metal layer and ensure the accuracy of the detection.
Specifically, the optical fiber current transformer 1 is based on the principle that the current measured by the faraday magneto-optical effect is obtained by the following formula:
in the formula, V is a Verdet constant of the optical medium and represents an optical rotation angle caused by a unit magnetic field, l is a distance of light propagating in the medium, H is a magnetic field intensity, N is the number of turns of a closed optical fiber sensing ring at a position surrounding a submarine cable terminal flange, and I is the magnitude of current flowing through a submarine cable conductor.
Because the submarine cable is bound with the laid optical cable or the internal composite optical fiber, the real-time distribution of the surface temperature of the submarine cable can be directly monitored by utilizing a distributed optical fiber sensing (DTS) principle, taking Hainan networking engineering as an example, the cable is about 31km long, a distributed optical fiber sensor based on Brillouin scattering is adopted, and the measured surface temperature of the submarine cable can be obtained according to the following formula:
νB(t)＝νB(tr)[1+Ct(t-tr)](2)
in the formula, vB(t) is the temperature-induced Brillouin frequency shift trIs a reference temperature; t is the measured temperature; v isB(tr) Is the Brillouin frequency shift at the reference temperature; ctTemperature coefficient of。
When knowing the surface temperature of the submarine cable and the current flowing through the cable conductor, the temperature of the conductor can be calculated as follows:
in the formula, vB(t) is the temperature-induced Brillouin frequency shift trIs a reference temperature; t is the measured temperature; v isB(tr) Is the Brillouin frequency shift at the reference temperature; ctTemperature coefficient. ThetacIs the temperature of the submarine cable conductor; thetaaThe temperature of the conductor on the surface of the submarine cable can be measured by the formula (2) to be distributed along the line in real time; i, obtaining the current flowing through the submarine cable conductor by the formula (1); r is the resistance of the conductor of the submarine cable in unit length; wdDielectric loss per unit length, W, of submarine cabled＝ωCU2tan δ, ω ═ 2 π f, C is the capacitance per unit length of the submarine cable, U is the conductor voltage to ground, tan δ is the dielectric loss tangent; lambda [ alpha ]1And λ1The loss coefficient of the lead alloy sheath and the loss coefficient of the armor are respectively; t is1、T2And T3Thermal resistances between the conductor and the lead alloy sheath, between the lead alloy sheath and the armor, and the outer layer, T4N is the thermal resistance of the surrounding environment of the submarine cable, the number of conductors in the submarine cable is n equal to 1, and the number of conductors in the submarine cable is n equal to 3. Except the current and the surface temperature of the submarine cable, other parameters are determined values after the submarine cable is produced, manufactured, laid and installed.
Based on the above-mentioned equipment and principle, the temperature of the submarine cable conductor can be obtained as follows:
wherein the content of the first and second substances,
is the faraday rotation angle.
Considering that the heat generated by the submarine cable conductor is joule heat and is only related to resistive current, when calculating the temperature of the submarine cable conductor, the optical fiber current transformer should correct:
the submarine cable conductor temperature can be obtained as follows:
therefore, the temperature of the conductor of the submarine cable can be accurately monitored in the mode, and the running state of the submarine cable can be more accurately evaluated. Specifically, in this embodiment, the online monitoring terminal 3 is a computer, the above calculation and solving processes are all performed in a processor of the computer, and after the calculation processing, the result can be displayed through a display screen, so that the monitoring result can be obtained by the staff.
In summary, the all-fiber temperature online monitoring system for the submarine cable provided by the embodiment comprehensively applies the distributed optical fiber sensing technology, the optical fiber current transformer technology and the submarine cable heat conduction model principle to realize the all-fiber type submarine cable temperature online monitoring. By adopting the monitoring principle, the current error of the traditional monitoring mode is avoided, the temperature of the submarine cable conductor is more accurately monitored, and the running state of the submarine cable is more accurately evaluated. In addition, the equipment scale is smaller, the installation and later-period maintenance are more convenient, the cost is greatly shortened, and the maintenance work of oil-filled and gas-filled equipment is avoided.
Example 2:
the embodiment provides an all-fiber temperature online monitoring method for an undersea cable, wherein the undersea cable is bound with an optical cable or internally compounded with optical fibers, and the method comprises the following steps:
the optical fiber sensing ring of the optical fiber current transformer is arranged at a flange at the lower part of a submarine cable terminal, and the armor and the lead sheath of the submarine cable are stripped at the installation position before installation, so that the interference of the induced power of an external metal layer is avoided, and the detection accuracy is ensured.
Monitoring the real-time temperature distribution on the surface of the submarine cable by using a distributed optical fiber sensor to the bundled optical cable or the composite optical fiber of the submarine cable;
the current parameters measured and obtained by the optical fiber current transformer and the real-time temperature distribution parameters on the surface of the submarine cable monitored and obtained by the distributed optical fiber sensor are received through the online monitoring terminal, the real-time temperature distribution condition of the conductor of the submarine cable is displayed and output according to the two parameters, and finally online monitoring is realized in an all-optical fiber mode.
Therefore, the method realizes the online monitoring of the submarine cable temperature by adopting the all-fiber form, avoids the problem that the traditional transformer substation current transformer cannot accurately measure the short plate of the current flowing through the submarine cable conductor, and provides more accurate data for the calculation of the submarine cable conductor temperature; the online monitoring is carried out in an all-fiber mode, so that direct contact with a primary high-voltage and large-current part is avoided, accidents such as electric shock and the like are avoided, short-circuit and open-circuit faults are avoided, and accidents such as discharge and explosion are avoided; the online monitoring is carried out in an all-fiber mode, so that the equipment is more miniaturized, and the installation and maintenance are more economical and more economical; the maintenance of the equipment can be avoided, and the complex maintenance work of the conventional oil-filled and gas-filled equipment can be avoided.
Specifically, the main principle of the optical fiber current transformer is based on the faraday magneto-optical effect, and the measured current is obtained by the following formula:
in the formula, V is a Verdet constant of the optical medium and represents an optical rotation angle caused by a unit magnetic field, l is a distance of light propagating in the medium, H is a magnetic field intensity, N is the number of turns of a closed optical fiber sensing ring at a position surrounding a submarine cable terminal flange, and I is the magnitude of current flowing through a submarine cable conductor.
Because the submarine cable is bound with the laid optical cable or the internal composite optical fiber, the real-time distribution of the surface temperature of the submarine cable can be directly monitored by utilizing a distributed optical fiber sensing (DTS) principle, taking Hainan networking engineering as an example, the cable is about 31km long, a distributed optical fiber sensor based on Brillouin scattering is adopted, and the measured surface temperature of the submarine cable can be obtained according to the following formula:
νB(t)＝νB(tr)[1+Ct(t-tr)](2)
in the formula, vB(t) is the temperature-induced Brillouin frequency shift trIs a reference temperature; t is the measured temperature; v isB(tr) Is the Brillouin frequency shift at the reference temperature; ctTemperature coefficient.
When knowing the surface temperature of the submarine cable and the current flowing through the cable conductor, the temperature of the conductor can be calculated as follows:
in the formula, vB(t) is the temperature-induced Brillouin frequency shift trIs a reference temperature; t is the measured temperature; v isB(tr) Is the Brillouin frequency shift at the reference temperature; ctTemperature coefficient. ThetacIs the temperature of the submarine cable conductor; thetaaThe temperature of the conductor on the surface of the submarine cable can be measured by the formula (2) to be distributed along the line in real time; i, obtaining the current flowing through the submarine cable conductor by the formula (1); r is the resistance of the conductor of the submarine cable in unit length; wdDielectric loss per unit length, W, of submarine cabled＝ωCU2tan δ, ω ═ 2 π f, C is the capacitance per unit length of the submarine cable, U is the conductor voltage to ground, tan δ is the dielectric loss tangent; lambda [ alpha ]1And λ1The loss coefficient of the lead alloy sheath and the loss coefficient of the armor are respectively; t is1、T2And T3Thermal resistances between the conductor and the lead alloy sheath, between the lead alloy sheath and the armor, and the outer layer, T4N is the thermal resistance of the surrounding environment of the submarine cable, the number of conductors in the submarine cable is n equal to 1, and the number of conductors in the submarine cable is n equal to 3. Except the current and the surface temperature of the submarine cable, other parameters are determined values after the submarine cable is produced, manufactured, laid and installed.
Based on the above-mentioned equipment and principle, the temperature of the submarine cable conductor can be obtained as follows:
wherein the content of the first and second substances,
is the faraday rotation angle.
Considering that the heat generated by the submarine cable conductor is joule heat and is only related to resistive current, when calculating the temperature of the submarine cable conductor, the optical fiber current transformer should correct:
the submarine cable conductor temperature can be obtained as follows:
therefore, the temperature of the submarine cable conductor can be accurately monitored by the method, and the running state of the submarine cable can be more accurately evaluated. Specifically, in this embodiment, the online monitoring terminal is a computer, the above-mentioned operation solving process is performed in a processor of the computer, and after the operation processing, the result can be displayed through a display screen, so that the monitoring result can be obtained by the staff.
In summary, the all-fiber temperature online monitoring method for the submarine cable provided by the embodiment comprehensively applies the distributed optical fiber sensing technology, the optical fiber current transformer technology and the submarine cable heat conduction model principle to realize the all-fiber submarine cable temperature online monitoring. By adopting the monitoring principle, the current error of the traditional monitoring mode is avoided, the temperature of the submarine cable conductor is more accurately monitored, and the running state of the submarine cable is more accurately evaluated. In addition, the equipment scale is smaller, the installation and later-period maintenance are more convenient, the cost is greatly shortened, and the maintenance work of oil-filled and gas-filled equipment is avoided.
The above embodiments are only for illustrating the technical concept and features of the present invention, and the purpose thereof is to enable those skilled in the art to understand the contents of the present invention and implement the present invention accordingly, and not to limit the protection scope of the present invention accordingly. All equivalent changes or modifications made in accordance with the spirit of the present disclosure are intended to be covered by the scope of the present disclosure.
Claims (10)
1. The utility model provides a submarine cable all-fiber temperature on-line monitoring system, submarine cable bundle has optical cable or inside complex has optic fibre, its characterized in that, monitoring system includes:
a fiber optic current transformer for installation at a submarine cable termination location for measuring and acquiring current flowing through a submarine cable conductor;
the distributed optical fiber sensor is used for monitoring the temperature distribution on the surface of the submarine cable in real time;
and the online monitoring terminal is used for receiving the current parameters obtained by the optical fiber current transformer and the real-time temperature distribution parameters on the surface of the submarine cable obtained by the distributed optical fiber sensor, and displaying and outputting the real-time temperature distribution condition of the submarine cable conductor according to the two parameters.
2. The all-fiber temperature on-line monitoring system for submarine cables according to claim 1, wherein the fiber-optic current transformer is installed at the flange of the lower part of the submarine cable terminal through its fiber-optic sensing ring, where the sheath and lead sheath of the submarine cable are stripped.
3. The submarine cable all-fiber temperature on-line monitoring system according to claim 2, wherein the measured current of said fiber-optic current transformer is obtained by:
in the formula, V is a Verdet constant of the optical medium and represents an optical rotation angle caused by a unit magnetic field, l is a distance of light propagating in the medium, H is a magnetic field intensity, N is the number of turns of a closed optical fiber sensing ring at a position surrounding a submarine cable terminal flange, and I is the magnitude of current flowing through a submarine cable conductor.
4. The all-fiber temperature online monitoring system for submarine cables according to claim 3, wherein the distributed fiber sensor is a distributed fiber sensor based on Brillouin scattering, and the measured surface temperature of the submarine cable is obtained according to the following formula:
νB(t)＝νB(tr)[1+Ct(t-tr)](2)
in the formula, vB(t) is the temperature-induced Brillouin frequency shift trIs a reference temperature; t is the measured temperature; v isB(tr) Is the Brillouin frequency shift at the reference temperature; ctTemperature coefficient.
5. The submarine cable all-fiber temperature online monitoring system according to claim 4, wherein the online monitoring terminal displays the real-time distribution of the submarine cable conductor temperature according to the two parameters in a manner that:
knowing the surface temperature of the submarine cable and the current flowing through the cable conductor, the conductor temperature is calculated as follows:
in the formula, vB(t) is the temperature-induced Brillouin frequency shift trIs a reference temperature; t is the measured temperature; v isB(tr) Is the Brillouin frequency shift at the reference temperature; ctA temperature coefficient; thetacIs the temperature of the submarine cable conductor; thetaaThe temperature of the conductor on the surface of the submarine cable can be measured by the formula (2) to be distributed along the line in real time; i, obtaining the current flowing through the submarine cable conductor by the formula (1); r is the resistance of the conductor of the submarine cable in unit length; wdDielectric loss per unit length, W, of submarine cabled＝ωCU2tan δ, ω ═ 2 π f, C is the capacitance per unit length of the submarine cable, U is the conductor voltage to ground, tan δ is the dielectric loss tangent; lambda [ alpha ]1And λ1The loss coefficient of the lead alloy sheath and the loss coefficient of the armor are respectively; t is1、T2And T3Thermal resistances between the conductor and the lead alloy sheath, between the lead alloy sheath and the armor, and the outer layer, T4The thermal resistance of the surrounding environment of the submarine cable is shown, n is the number of conductors in the submarine cable, the single-core cable n is 1, and the three-core cable n is 3; except the current and the surface temperature of the submarine cable, other parameters are determined values after the submarine cable is produced, manufactured, laid and installed;
based on the above, the obtained temperature of the submarine cable conductor is:
wherein the content of the first and second substances,
is the faraday rotation angle.
6. The all-fiber submarine cable temperature on-line monitoring system according to claim 5, wherein the means for displaying the real-time distribution of the submarine cable conductor output by the on-line monitoring terminal according to the two parameters further comprises:
correcting the optical fiber current transformer:
the conductor temperature of the submarine cable is obtained as follows:
7. an all-fiber temperature online monitoring method for an undersea cable, wherein the undersea cable is bound with an optical cable or internally compounded with optical fibers, and the method is characterized by comprising the following steps:
installing an optical fiber sensing ring of the optical fiber current transformer at a flange at the lower part of a submarine cable terminal, wherein the armor and the lead sheath of the submarine cable are stripped at the installation position before installation;
monitoring the real-time temperature distribution on the surface of the submarine cable by using a distributed optical fiber sensor to the bundled optical cable or the composite optical fiber of the submarine cable;
and receiving the current parameters measured and obtained by the optical fiber current transformer and the real-time temperature distribution parameters on the surface of the submarine cable monitored and obtained by the distributed optical fiber sensor through the online monitoring terminal, and displaying and outputting the real-time temperature distribution condition of the submarine cable conductor according to the two parameters.
8. The method for on-line monitoring the all-fiber temperature of the submarine cable according to claim 7, wherein the current measured by the fiber-optic current transformer is obtained by the following formula:
in the formula, V is a Verdet constant of the optical medium and represents an optical rotation angle caused by a unit magnetic field, l is a distance of light propagating in the medium, H is a magnetic field intensity, N is the number of turns of a closed optical fiber sensing ring at a position surrounding a submarine cable terminal flange, and I is the magnitude of current flowing through a submarine cable conductor.
9. The all-fiber temperature online monitoring system for submarine cables according to claim 8, wherein the distributed fiber sensor is a distributed fiber sensor based on brillouin scattering, and the measured surface temperature of the submarine cable is obtained according to the following formula:
νB(t)＝νB(tr)[1+Ct(t-tr)](2)
in the formula, vB(t) temperature induced BrillouinFrequency shift trIs a reference temperature; t is the measured temperature; v isB(tr) Is the Brillouin frequency shift at the reference temperature; ctTemperature coefficient.
10. The submarine cable all-fiber temperature online monitoring system according to claim 9, wherein the online monitoring terminal outputs the real-time distribution of the submarine cable conductor temperature according to the two parameters in a manner that:
knowing the surface temperature of the submarine cable and the current flowing through the cable conductor, the conductor temperature is calculated as follows:
in the formula, vB(t) is the temperature-induced Brillouin frequency shift trIs a reference temperature; t is the measured temperature; v isB(tr) Is the Brillouin frequency shift at the reference temperature; ctA temperature coefficient; thetacIs the temperature of the submarine cable conductor; thetaaThe temperature of the conductor on the surface of the submarine cable can be measured by the formula (2) to be distributed along the line in real time; i, obtaining the current flowing through the submarine cable conductor by the formula (1); r is the resistance of the conductor of the submarine cable in unit length; wdDielectric loss per unit length, W, of submarine cabled＝ωCU2tan δ, ω ═ 2 π f, C is the capacitance per unit length of the submarine cable, U is the conductor voltage to ground, tan δ is the dielectric loss tangent; lambda [ alpha ]1And λ1The loss coefficient of the lead alloy sheath and the loss coefficient of the armor are respectively; t is1、T2And T3Thermal resistances between the conductor and the lead alloy sheath, between the lead alloy sheath and the armor, and the outer layer, T4The thermal resistance of the surrounding environment of the submarine cable is shown, n is the number of conductors in the submarine cable, the single-core cable n is 1, and the three-core cable n is 3; except the current and the surface temperature of the submarine cable, other parameters are determined values after the submarine cable is produced, manufactured, laid and installed;
based on the above, the obtained temperature of the submarine cable conductor is:
wherein the content of the first and second substances,is the Faraday rotation angle;
correcting the optical fiber current transformer:
the conductor temperature of the submarine cable is obtained as follows:
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911175481.9A CN110793665A (en) | 2019-11-26 | 2019-11-26 | Submarine cable all-fiber temperature online monitoring system and monitoring method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911175481.9A CN110793665A (en) | 2019-11-26 | 2019-11-26 | Submarine cable all-fiber temperature online monitoring system and monitoring method |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN110793665A true CN110793665A (en) | 2020-02-14 |
Family
ID=69446287
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201911175481.9A Pending CN110793665A (en) | 2019-11-26 | 2019-11-26 | Submarine cable all-fiber temperature online monitoring system and monitoring method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110793665A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112986650A (en) * | 2021-01-20 | 2021-06-18 | 河南平高电气股份有限公司 | All-fiber current transformer and temperature compensation method thereof |
-
2019
- 2019-11-26 CN CN201911175481.9A patent/CN110793665A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112986650A (en) * | 2021-01-20 | 2021-06-18 | 河南平高电气股份有限公司 | All-fiber current transformer and temperature compensation method thereof |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| WO2020151032A1 (en) | High-temperature superconducting cable temperature measurement system | |
| CN110954471B (en) | Electrochemical corrosion off-line detection and evaluation method for water-blocking buffer layer of high-voltage power cable | |
| US10139433B2 (en) | Method of measuring current distribution in high and medium voltage cables | |
| CN110082636A (en) | A kind of power cable fault localization method and system | |
| Song et al. | Online multi-parameter sensing and condition assessment technology for power cables: A review | |
| CN205175574U (en) | Cable intermediate head conductor temperature measures structure | |
| CN103592054A (en) | Method and device for determining temperature of cable group cable cores and installation method of device | |
| Xu et al. | Application of temperature field modeling in monitoring of optic-electric composite submarine cable with insulation degradation | |
| CN102507042B (en) | Method for embedding optical fiber sensor in intelligent grid power cable | |
| CN110793665A (en) | Submarine cable all-fiber temperature online monitoring system and monitoring method | |
| CN202997493U (en) | Intelligent cable connector | |
| CN211234772U (en) | Submarine cable all-fiber temperature online monitoring system | |
| Chen et al. | The 500kV oil-filled submarine cable temperature monitoring system based on BOTDA distributed optical fiber sensing technology | |
| WO2009079919A1 (en) | High voltage power cable terminal | |
| CN205333812U (en) | Test system of high -voltage switch contact | |
| CN207909571U (en) | A kind of medium-pressure power cable with protection copper strips | |
| Huang et al. | Temperature Online Monitoring of Submarine Cable Based on BOTDA and FOCT | |
| CN206833970U (en) | A kind of lv power cable with protection copper strips | |
| CN202403707U (en) | Optical fiber sensor device with embedded intelligent electrical network power cable | |
| CN110726862A (en) | Integrated optical sensor probe for measuring broadband high-amplitude current | |
| Wang et al. | Fault location in the outer sheath of power cables | |
| Huang et al. | Simulation Analysis of Grounding Characteristics of Cable Based on ATP-EMTP | |
| Wang et al. | Analysis of power cable fault diagnosis and electric field detection technology based on computer control system | |
| Deng et al. | Research on the Effect of Protection Box on the Temperature of the Cable Intermediate Joint | |
| Huang et al. | Calculation and Measurement of Sequence Parameters of Three-Core Submarine Cable with Semi-conductive Sheaths |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |