A dynamic submarine cable settlement monitoring and analysis method based on optical fiber temperature measurement

Abstract

The present invention relates to a dynamic submarine cable settlement monitoring and analysis method based on optical fiber temperature measurement, which belongs to the field of dynamic submarine cable settlement monitoring. The method includes establishing a dynamic submarine cable optical fiber temperature data set; obtaining a dynamic submarine cable platform side water entry point according to the dynamic submarine cable optical fiber temperature data set; obtaining a dynamic submarine cable platform side mud entry point and a dynamic submarine cable fan side mud entry point according to the dynamic submarine cable optical fiber temperature data set, and defining a settlement analysis temperature observation point and a settlement analysis temperature reference point; determining the seawater temperature stratification according to the temperature difference sequence, the seawater temperature stratification includes a constant temperature layer and a linear layer; obtaining a linear layer optical fiber temperature resolution according to the linear layer depth; and obtaining a dynamic cable settlement distance based on the dynamic submarine cable optical fiber temperature data set and the linear layer optical fiber temperature resolution. The present invention realizes the judgment of whether the dynamic submarine cable has settled by temperature data, and realizes the monitoring of the settlement state of the dynamic submarine cable.

Description

Technical Field

[0001] The invention belongs to the technical field of dynamic submarine cable settlement monitoring, and in particular relates to a dynamic submarine cable settlement monitoring and analysis method based on optical fiber temperature measurement. Background Art

[0002] Offshore wind power, especially floating wind power, has become an important direction for future offshore energy utilization. Compared with traditional fixed wind power systems, floating wind power systems have greater adaptability and deployment flexibility, and are particularly suitable for deep sea areas.

[0003] Dynamic submarine cables are key media for power and communication transmission. One end of the cable is connected to the bottom of the floating wind turbine and suspended in the seawater in an S-shaped manner. The other end is connected to the fixed platform section, and the middle part of the cable is buried under the seabed. Dynamic submarine cables in floating wind power systems face more complex working environments and severe technical challenges than fixed submarine cables. In addition to the need to withstand natural environmental loads such as wind, waves, and ocean currents, factors such as the attachment of marine organisms, changes in seabed geology, and fluctuations in seawater temperature and salinity will have a significant impact on the physical form and transmission performance of the submarine cable, thereby affecting the stability and safety of the system. The settlement phenomenon will cause abnormal changes in the temperature and other related physical quantities of the dynamic submarine cable, thereby affecting the working performance of the submarine cable. If the settlement of the submarine cable is not monitored and analyzed in a timely manner, it may lead to unstable power transmission and even safety hazards such as cable damage. Therefore, timely and accurate detection of the settlement state of the dynamic submarine cable is crucial to ensure the normal operation of the wind power system.

[0004] At present, the monitoring of the operating status of dynamic submarine cables is mainly achieved by using distributed optical fiber sensing technology. Commonly used equipment includes distributed optical fiber temperature measurement systems, which can detect the real-time temperature value of the entire submarine cable, analyze the temperature characteristics before and after the submarine cable settles, and further summarize the dynamic submarine cable settlement analysis method. However, due to the many influencing factors in the marine environment, marine biological attachment, seabed geological changes, etc. have a significant impact on the linearity of dynamic submarine cables. At the same time, the ambient temperature will also cause differences in the detected dynamic submarine cable temperature curve. Therefore, there is no universal method to analyze the settlement state of dynamic submarine cables. Summary of the invention

[0005] In order to solve the above problems existing in the prior art, the present invention provides a dynamic submarine cable settlement monitoring and analysis method based on optical fiber temperature measurement.

[0006] The purpose of the present invention can be achieved through the following technical solutions:

[0007] A dynamic submarine cable settlement monitoring and analysis method based on optical fiber temperature measurement, the implementation of the dynamic submarine cable settlement monitoring and analysis method comprising the following steps:

[0008] Establish a dynamic submarine cable optical fiber temperature data set based on distributed optical fiber temperature monitors;

[0009] Acquire the water entry point on the side of the dynamic submarine cable platform according to the dynamic submarine cable optical fiber temperature data set;

[0010] According to the dynamic submarine cable optical fiber temperature data set, a dynamic submarine cable platform side mud entry point and a dynamic submarine cable fan side mud entry point are obtained, and a settlement analysis temperature observation point and a settlement analysis temperature reference point are defined;

[0011] Determining seawater temperature stratification according to the temperature difference sequence, wherein the seawater temperature stratification includes a constant temperature layer and a linear layer;

[0012] The linear layer optical fiber temperature resolution is obtained according to the linear layer depth;

[0013] A dynamic cable settlement distance is obtained based on the dynamic submarine cable optical fiber temperature data set and the linear layer optical fiber temperature resolution, and the dynamic cable settlement distance includes a dynamic cable monthly settlement distance and a dynamic cable annual settlement distance.

[0014] Preferably, the establishing of a dynamic submarine cable optical fiber temperature data set based on a distributed optical fiber temperature monitor comprises:

[0015] A target position and a target time period are preset, and a dynamic submarine cable optical fiber initial temperature set is obtained based on a distributed optical fiber temperature monitor. The dynamic submarine cable optical fiber initial temperature set is a collection of optical fiber initial temperature data of the dynamic submarine cable at the target position and the target time period. The dynamic submarine cable optical fiber initial temperature set is smoothed by a Gaussian weighted moving average filtering algorithm to obtain the dynamic submarine cable optical fiber temperature data set. The window size of the Gaussian weighted moving average filtering algorithm is set to 15, and the standard deviation of the Gaussian distribution is set to 5.

[0016] Preferably, obtaining the dynamic submarine cable platform side water entry point according to the dynamic submarine cable optical fiber temperature data set comprises:

[0017] The dynamic submarine cable optical fiber temperature data sets of the dynamic submarine cable under high current and low current are respectively obtained and regarded as continuous functions, and the temperature target function is calculated according to the continuous function. The calculation formula is: , where T s is the temperature objective function, T hs is a continuous function under low current, T ls It is a continuous function under the action of high current. The position range of the water entry point on the dynamic submarine cable platform side is located. The minimum value of the temperature objective function is obtained by using the least squares optimization algorithm within the position range. The water entry point on the dynamic submarine cable platform side is the target position corresponding to the minimum value of the temperature objective function.

[0018] Preferably, the obtaining of the dynamic submarine cable platform side mud entry point and the dynamic submarine cable fan side mud entry point according to the dynamic submarine cable optical fiber temperature data set, and defining the settlement analysis temperature observation point and the settlement analysis temperature reference point comprises:

[0019] The temperature change rate of the data points in the dynamic submarine cable optical fiber temperature data set is calculated by the finite difference method, and the calculation formula is: , where k i is the temperature change rate at the i-th target position, t i+1 is the temperature data of the dynamic submarine cable optical fiber at the i+1th target position, t i is the dynamic submarine cable optical fiber temperature data at the i-th target location, x i+1 is the i+1th target position, x i is the i-th target position, N is the number of preset target positions;

[0020] The temperature change rate difference is calculated according to the temperature change rate and a temperature change rate difference sequence is formed. The calculation formula of the temperature change rate difference is: ,in, is the temperature change rate difference at the i-th target position, k i+1 is the temperature change rate at the i+1th target position;

[0021] A temperature change rate difference threshold is preset, and after the dynamic submarine cable platform side water entry point, two data points whose temperature change rate difference is less than the temperature change rate difference threshold are sequentially searched in the temperature change rate difference sequence, and the target position corresponding to the first searched data point is used as the dynamic submarine cable platform side mud entry point, and the target position corresponding to the later searched data point is used as the dynamic submarine cable fan side mud entry point;

[0022] After the data point corresponding to the mud entry point of the dynamic submarine cable wind turbine side, use the sign change detection algorithm in the temperature change rate difference sequence to find the data point where the temperature change rate changes from positive to negative, and use the corresponding target position as the settlement analysis temperature observation point;

[0023] The data points after the settlement analysis temperature observation point in the temperature change rate difference sequence are traversed, and the data point equal to the dynamic submarine cable optical fiber temperature data of the settlement analysis temperature observation point is defined as the settlement analysis temperature reference point.

[0024] Preferably, the seawater temperature stratification is determined according to the temperature difference sequence, and the seawater temperature stratification includes a constant temperature layer and a linear layer, including:

[0025] Acquire a layered temperature set, the layered temperature set is a temperature data set of the dynamic submarine cable optical fiber between the water entry point on the dynamic submarine cable platform side and the mud entry point on the dynamic submarine cable platform side, acquire the layered temperature set under the action of the low current and extract a data point every 1m to form a temperature sequence, and calculate the difference between adjacent data points in the temperature sequence to form the temperature difference sequence;

[0026] A temperature difference threshold, a temperature difference mean square error threshold and a temperature difference mean threshold are preset. When the 1st to jth data in the temperature difference sequence are all less than or equal to the temperature difference threshold, the mean square error of the 1st to jth data is less than the temperature difference mean square error threshold, and the mean of the data after the jth data is greater than or equal to the temperature difference mean threshold, the target position corresponding to the jth data is the dividing point between the isothermal layer and the linear layer, and the seawater is divided into the isothermal layer and the linear layer based on the dividing point.

[0027] Preferably, obtaining the linear layer optical fiber temperature resolution according to the linear layer depth includes:

[0028] Acquire the linear layer depth, when the dynamic submarine cable enters the water in a vertical state, the linear layer depth is the linear layer submarine cable length;

[0029] Obtain the total temperature difference of the linear layer, and calculate the temperature resolution of the optical fiber of the linear layer based on the linear layer depth and the total temperature difference of the linear layer. The calculation formula is: , where R z is the linear layer fiber temperature resolution in the zth month, is the total temperature difference of the linear layer in the zth month, h z is the linear layer depth of the zth month.

[0030] Preferably, obtaining the dynamic cable settlement distance based on the dynamic submarine cable optical fiber temperature data set and the linear layer optical fiber temperature resolution comprises:

[0031] Obtaining a settlement analysis temperature difference, the settlement analysis temperature difference being the temperature difference between the settlement analysis temperature observation point and the settlement analysis temperature reference point, and recording the settlement analysis temperature difference of the Uth month when the dynamic cable is not initially settled in units of five days to form a settlement analysis temperature difference sequence;

[0032] Obtain the mean value of the settlement analysis temperature difference sequence and the standard deviation of the settlement analysis temperature difference sequence, and calculate the settlement temperature threshold of the dynamic submarine cable. The calculation formula is: , where Q is the temperature threshold of dynamic submarine cable settlement, is the mean value of the temperature difference series of the settlement analysis in the Uth month, is the standard deviation of the temperature difference series in the settlement analysis of month U;

[0033] When the settlement analysis temperature difference in the uth month is greater than or equal to the dynamic submarine cable settlement temperature threshold, the dynamic submarine cable settles in the uth month. The calculation formula for the dynamic cable monthly settlement distance is: , where H Y is the monthly settlement distance of the dynamic cable, is the temperature difference of the settlement analysis in the uth month, R u is the linear layer fiber temperature resolution in the uth month;

[0034] Obtain the settlement analysis temperature difference of the sth month in the Sth year and the settlement analysis temperature difference of the sth month in the S-1st year. When the settlement analysis temperature difference of the sth month in the Sth year is greater than the settlement analysis temperature difference of the sth month in the S-1st year, the dynamic submarine cable settles in the Sth year. The calculation formula for the annual settlement distance of the dynamic cable is: , where H is the annual settlement distance of the dynamic cable, is the temperature difference for the settlement analysis in the sth month of the sth year, is the temperature difference of the settlement analysis in the sth month of the sth year, R s is the linear layer fiber temperature resolution in the sth month of the sth year.

[0035] A dynamic submarine cable settlement monitoring and analysis device based on optical fiber temperature measurement, used to execute the above-mentioned dynamic submarine cable settlement monitoring and analysis method, including a data acquisition module, a key point acquisition module, a seawater stratification module and a settlement distance acquisition module;

[0036] The data acquisition module is used to establish a dynamic submarine cable optical fiber temperature data set based on a distributed optical fiber temperature monitor;

[0037] The key point acquisition module is used to acquire the water entry point on the side of the dynamic submarine cable platform according to the dynamic submarine cable optical fiber temperature data set; acquire the mud entry point on the side of the dynamic submarine cable platform and the mud entry point on the side of the dynamic submarine cable fan according to the dynamic submarine cable optical fiber temperature data set, and define the settlement analysis temperature observation point and the settlement analysis temperature reference point;

[0038] The seawater stratification module is used to determine the seawater temperature stratification according to the temperature difference sequence, and the seawater temperature stratification includes a constant temperature layer and a linear layer; and obtain the linear layer optical fiber temperature resolution according to the linear layer depth;

[0039] The settlement distance acquisition module is used to obtain the dynamic cable settlement distance based on the dynamic submarine cable optical fiber temperature data set and the linear layer optical fiber temperature resolution, and the dynamic cable settlement distance includes the dynamic cable monthly settlement distance and the dynamic cable annual settlement distance.

[0040] An electronic device comprises a memory, a processor and a computer program stored in the memory and executable on the processor, wherein the processor implements the above-mentioned dynamic submarine cable settlement monitoring and analysis method when executing the program.

[0041] A storage medium containing computer executable instructions, which are used to execute the above-mentioned dynamic submarine cable settlement monitoring and analysis method when executed by a computer processor.

[0042] The beneficial effects of the present invention are:

[0043] Through the comprehensive application of optical fiber temperature monitoring and real-time data analysis methods, targeting dynamic cables with complex working conditions in marine environments, and combining the linear characteristics of dynamic cables in seawater, the temperature difference of temperature data under high and low currents and the temperature change rate under arbitrary currents are calculated to obtain the characteristic points of settlement analysis. A method for judging the settlement state of dynamic cables by calculating the temperature difference between the observation point and the reference point is proposed. This method can eliminate the simultaneous influence of factors such as the environment and ocean currents on the suspension state, and solves the problem of monitoring the settlement state of dynamic submarine cables during online operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to facilitate understanding by those skilled in the art, the present invention is further described below with reference to the accompanying drawings.

[0045] Figure 1 The present invention is a flowchart of the steps of a dynamic submarine cable settlement monitoring and analysis method based on optical fiber temperature measurement. DETAILED DESCRIPTION

[0046] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the specific implementation methods, structures, features and effects of the present invention are described in detail below in conjunction with the accompanying drawings and preferred embodiments.

[0047] The working principle and use process of the present invention:

[0048] See also Figure 1 , a dynamic submarine cable settlement monitoring and analysis method based on optical fiber temperature measurement, comprising:

[0049] S1: Establish a dynamic submarine cable optical fiber temperature dataset based on distributed optical fiber temperature monitor;

[0050] S2: obtaining a water entry point on the dynamic submarine cable platform side according to the dynamic submarine cable optical fiber temperature data set, where the water entry point is the intersection of the dynamic submarine cable optical fiber temperature curves under the action of high current and low current when the ambient temperature is the same;

[0051] S3: According to the dynamic submarine cable optical fiber temperature data set, the mud entry point on the dynamic submarine cable platform side and the mud entry point on the dynamic submarine cable fan side are obtained, and the settlement analysis temperature observation point and the settlement analysis temperature reference point are defined. The settlement analysis temperature observation point is the highest temperature point of the dynamic submarine cable buoy section, and the settlement analysis temperature reference point is a position close to the dynamic submarine cable fan side and isothermal with the settlement analysis temperature observation point;

[0052] S4: determining the seawater temperature stratification according to the temperature difference sequence, wherein the seawater temperature stratification includes a constant temperature layer and a linear layer;

[0053] S5: Obtaining the linear layer fiber temperature resolution according to the linear layer depth;

[0054] S6: Obtain a dynamic cable settlement distance based on the dynamic submarine cable optical fiber temperature data set and the linear layer optical fiber temperature resolution, wherein the dynamic cable settlement distance includes a dynamic cable monthly settlement distance and a dynamic cable annual settlement distance.

[0055] In this embodiment, a dynamic submarine cable optical fiber temperature data set is established based on a distributed optical fiber temperature monitor, which can be implemented by the following steps:

[0056] A target position and a target time period are preset, and a dynamic submarine cable optical fiber initial temperature set is obtained based on a distributed optical fiber temperature monitor. The dynamic submarine cable optical fiber initial temperature set is a collection of optical fiber initial temperature data of the dynamic submarine cable at the target position and the target time period. The dynamic submarine cable optical fiber initial temperature set is smoothed by a Gaussian weighted moving average filtering algorithm to obtain the dynamic submarine cable optical fiber temperature data set. The window size of the Gaussian weighted moving average filtering algorithm is set to 15, and the standard deviation of the Gaussian distribution is set to 5.

[0057] In this embodiment, obtaining the dynamic submarine cable platform side water entry point according to the dynamic submarine cable optical fiber temperature data set can be specifically implemented by the following steps:

[0058] The dynamic submarine cable optical fiber temperature data sets under high current and low current of the dynamic submarine cable are respectively obtained and regarded as continuous functions, wherein the high current is a current value greater than 80% of the current carrying capacity, and the low current is a current value less than 20% of the current carrying capacity. The temperature target function is calculated according to the continuous function, and the calculation formula is: , where T s is the temperature objective function, T hs is a continuous function under low current, T ls It is a continuous function under the action of high current. The position range of the water entry point on the dynamic submarine cable platform side is located. The minimum value of the temperature objective function is obtained by using the least squares optimization algorithm within the position range. The water entry point on the dynamic submarine cable platform side is the target position corresponding to the minimum value of the temperature objective function.

[0059] In this embodiment, the dynamic submarine cable platform side mud entry point and the dynamic submarine cable fan side mud entry point are obtained according to the dynamic submarine cable optical fiber temperature data set, and the settlement analysis temperature observation point and the settlement analysis temperature reference point are defined, which can be implemented by the following steps:

[0060] S301: Calculate the temperature change rate of the data points in the dynamic submarine cable optical fiber temperature data set by the finite difference method, and the calculation formula is: , where k i is the temperature change rate at the i-th target position, t i+1 is the temperature data of the dynamic submarine cable optical fiber at the i+1th target position, t i is the dynamic submarine cable optical fiber temperature data at the i-th target location, x i+1 is the i+1th target position, x i is the i-th target position, N is the number of preset target positions;

[0061] S302: Calculate the temperature change rate difference according to the temperature change rate and form a temperature change rate difference sequence. The calculation formula of the temperature change rate difference is: ,in, is the temperature change rate difference at the i-th target position, k i+1 is the temperature change rate at the i+1th target position;

[0062] S303: Preset a temperature change rate difference threshold, and after the dynamic submarine cable platform side water entry point, sequentially search for two data points whose temperature change rate difference is less than the temperature change rate difference threshold in the temperature change rate difference sequence, and the target position corresponding to the first searched data point is used as the dynamic submarine cable platform side mud entry point, and the target position corresponding to the later searched data point is used as the dynamic submarine cable fan side mud entry point;

[0063] S304: After the data point corresponding to the mud entry point of the dynamic submarine cable wind turbine side, use a sign change detection algorithm in the temperature change rate difference sequence to find the data point where the temperature change rate changes from positive to negative, and use the corresponding target position as the settlement analysis temperature observation point;

[0064] S305: traverse the data points after the settlement analysis temperature observation point in the temperature change rate difference sequence, and define the data point equal to the dynamic submarine cable optical fiber temperature data of the settlement analysis temperature observation point as the settlement analysis temperature reference point.

[0065] In this embodiment, the seawater temperature stratification is determined according to the temperature difference sequence, and the seawater temperature stratification includes a constant temperature layer and a linear layer, which can be specifically implemented by the following steps:

[0066] S401: Acquire a layered temperature set, which is a temperature data set of the dynamic submarine cable optical fiber between the water entry point on the dynamic submarine cable platform side and the mud entry point on the dynamic submarine cable platform side, acquire the layered temperature set under the action of the low current and extract a data point every 1m to form a temperature sequence, and calculate the difference between adjacent data points in the temperature sequence to form the temperature difference sequence;

[0067] S402: Preset a temperature difference threshold, a temperature difference mean square error threshold and a temperature difference average threshold. When the 1st to jth data in the temperature difference sequence are all less than or equal to the temperature difference threshold, the mean square error of the 1st to jth data is less than the temperature difference mean square error threshold, and the mean of the data after the jth data is greater than or equal to the temperature difference average threshold, the target position corresponding to the jth data is the dividing point between the isothermal layer and the linear layer, and the seawater is divided into the isothermal layer and the linear layer based on the dividing point.

[0068] In this embodiment, the linear layer optical fiber temperature resolution is obtained according to the linear layer depth, which can be implemented by the following steps:

[0069] S501: Acquire the linear layer depth. When the dynamic submarine cable enters the water in an approximately vertical state, the linear layer depth can be regarded as the linear layer submarine cable length.

[0070] S502: Obtain the total temperature difference of the linear layer, and calculate the temperature resolution of the optical fiber of the linear layer based on the linear layer depth and the total temperature difference of the linear layer. The calculation formula is: , where R z is the linear layer fiber temperature resolution in the zth month, is the total temperature difference of the linear layer in the zth month, h z is the linear layer depth of the zth month.

[0071] In this embodiment, the dynamic cable settlement distance is obtained based on the dynamic submarine cable optical fiber temperature data set and the linear layer optical fiber temperature resolution, which can be implemented by the following steps:

[0072] S601: Obtaining a settlement analysis temperature difference, where the settlement analysis temperature difference is the temperature difference between the settlement analysis temperature observation point and the settlement analysis temperature reference point, and recording the settlement analysis temperature difference of the Uth month when the dynamic cable is not initially settled in units of five days to form a settlement analysis temperature difference sequence;

[0073] S602: Obtain the mean value of the settlement analysis temperature difference sequence and the standard deviation of the settlement analysis temperature difference sequence, and calculate the settlement temperature threshold of the dynamic submarine cable. The calculation formula is: , where Q is the temperature threshold of dynamic submarine cable settlement, is the mean value of the temperature difference series of the settlement analysis in the Uth month, is the standard deviation of the temperature difference series in the settlement analysis of month U;

[0074] S603: When the settlement analysis temperature difference in the uth month is greater than or equal to the settlement temperature threshold of the dynamic submarine cable, the dynamic submarine cable settles in the uth month. The calculation formula for the monthly settlement distance of the dynamic cable is: , where H Y is the monthly settlement distance of the dynamic cable, is the temperature difference of the settlement analysis in the uth month, R u is the linear layer fiber temperature resolution in the uth month;

[0075] S604: Obtain the settlement analysis temperature difference of the sth month in the Sth year and the settlement analysis temperature difference of the sth month in the S-1st year. When the settlement analysis temperature difference of the sth month in the Sth year is greater than the settlement analysis temperature difference of the sth month in the S-1st year, the dynamic submarine cable settles in the Sth year. The calculation formula for the annual settlement distance of the dynamic cable is: , where H is the annual settlement distance of the dynamic cable, is the temperature difference for the settlement analysis in the sth month of the sth year, is the temperature difference of the settlement analysis in the sth month of the sth year, R s is the linear layer fiber temperature resolution in the sth month of the sth year.

[0076] A dynamic submarine cable settlement monitoring and analysis device based on optical fiber temperature measurement, comprising a data acquisition module, a key point acquisition module, a seawater stratification module and a settlement distance acquisition module;

[0077] The data acquisition module is used to establish a dynamic submarine cable optical fiber temperature data set based on a distributed optical fiber temperature monitor;

[0078] The key point acquisition module is used to obtain the water entry point on the dynamic submarine cable platform side according to the dynamic submarine cable optical fiber temperature data set, and the water entry point is the intersection of the dynamic submarine cable optical fiber temperature curves under the action of high current and low current when the ambient temperature is the same; obtain the mud entry point on the dynamic submarine cable platform side and the mud entry point on the dynamic submarine cable fan side according to the dynamic submarine cable optical fiber temperature data set, and define the settlement analysis temperature observation point and the settlement analysis temperature reference point, the settlement analysis temperature observation point is the highest temperature point of the dynamic submarine cable buoy section, and the settlement analysis temperature reference point is a position close to the dynamic submarine cable fan side that is isothermal with the settlement analysis temperature observation point;

[0079] The seawater stratification module is used to determine the seawater temperature stratification according to the temperature difference sequence, and the seawater temperature stratification includes a constant temperature layer and a linear layer; and obtain the linear layer optical fiber temperature resolution according to the linear layer depth;

[0080] The settlement distance acquisition module is used to obtain the dynamic cable settlement distance based on the dynamic submarine cable optical fiber temperature data set and the linear layer optical fiber temperature resolution, and the dynamic cable settlement distance includes the dynamic cable monthly settlement distance and the dynamic cable annual settlement distance.

[0081] The computer storage medium of the embodiment of the present invention may adopt any combination of one or more computer-readable media. The computer-readable medium may be a computer-readable signal medium or a computer-readable storage medium. The computer-readable storage medium may be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, device or device, or any combination of the above. More specific examples (non-exhaustive list) of computer-readable storage media include: an electrical connection with one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In this document, a computer-readable storage medium may be any tangible medium containing or storing a program that may be used by or in combination with an instruction execution system, device or device.

[0082] Computer-readable signal media may include data signals propagated in baseband or as part of a carrier wave, which carry computer-readable program code. Such propagated data signals may take a variety of forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination of the above. Computer-readable signal media may also be any computer-readable medium other than a computer-readable storage medium, which may send, propagate, or transmit a program for use by or in conjunction with an instruction execution system, apparatus, or device.

[0083] The program code included on the computer readable medium can be transmitted with any appropriate medium, including but not limited to wireless, electric wire, optical cable, RF, etc., or any suitable combination of the above. The computer program code for performing the operation of the present invention can be written in one or more programming languages ​​or their combinations, and the programming language includes object-oriented programming languages-such as Java, Smalltalk, C++, and also includes conventional procedural programming languages-such as "C" language or similar programming languages. The program code can be executed completely on the user's computer, partially on the user's computer, as an independent software package, partially on the user's computer and partially on the remote computer, or completely on the remote computer or server. In the case of a remote computer, the remote computer can be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or it can be connected to an external computer (for example, using an Internet service provider to connect through the Internet).

[0084] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technical personnel in this field can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A method for monitoring and analyzing dynamic submarine cable settlement based on optical fiber temperature measurement, characterized in that: The implementation of the dynamic submarine cable settlement monitoring and analysis method comprises the following steps: Establish a dynamic submarine cable optical fiber temperature data set based on distributed optical fiber temperature monitors; Obtaining the water entry point on the side of the dynamic submarine cable platform according to the dynamic submarine cable optical fiber temperature data set; including respectively obtaining the dynamic submarine cable optical fiber temperature data sets of the dynamic submarine cable under the action of high current and low current and treating them as continuous functions, calculating the temperature target function according to the continuous function, and the water entry point on the side of the dynamic submarine cable platform is the target position corresponding to the minimum value of the temperature target function; According to the dynamic submarine cable optical fiber temperature data set, a dynamic submarine cable platform side mud entry point and a dynamic submarine cable fan side mud entry point are obtained, and a settlement analysis temperature observation point and a settlement analysis temperature reference point are defined; Determining seawater temperature stratification according to the temperature difference sequence, wherein the seawater temperature stratification includes a constant temperature layer and a linear layer; The linear layer optical fiber temperature resolution is obtained according to the linear layer depth; A dynamic cable settlement distance is obtained based on the dynamic submarine cable optical fiber temperature data set and the linear layer optical fiber temperature resolution, and the dynamic cable settlement distance includes a dynamic cable monthly settlement distance and a dynamic cable annual settlement distance.

2. The dynamic submarine cable settlement monitoring and analysis method according to claim 1 is characterized in that: The establishment of a dynamic submarine cable optical fiber temperature data set based on a distributed optical fiber temperature monitor comprises: A target position and a target time period are preset, and a dynamic submarine cable optical fiber initial temperature set is obtained based on a distributed optical fiber temperature monitor. The dynamic submarine cable optical fiber initial temperature set is a collection of optical fiber initial temperature data of the dynamic submarine cable at the target position and the target time period. The dynamic submarine cable optical fiber initial temperature set is smoothed by a Gaussian weighted moving average filtering algorithm to obtain the dynamic submarine cable optical fiber temperature data set. The window size of the Gaussian weighted moving average filtering algorithm is set to 15, and the standard deviation of the Gaussian distribution is set to 5.

3. The dynamic submarine cable settlement monitoring and analysis method according to claim 1 is characterized in that: The high current is a current value greater than 80% of the current carrying capacity, the low current is a current value less than 20% of the current carrying capacity, and the calculation formula of the temperature objective function is: , where T s is the temperature objective function, T hs is a continuous function under low current, T ls It is a continuous function under the action of high current. The method for obtaining the minimum value of the temperature objective function includes locating the position range of the water entry point on the side of the dynamic submarine cable platform, and obtaining the minimum value of the temperature objective function by using a least squares optimization algorithm within the position range.

4. The dynamic submarine cable settlement monitoring and analysis method according to claim 1 is characterized in that: The obtaining of the dynamic submarine cable platform side mud entry point and the dynamic submarine cable fan side mud entry point according to the dynamic submarine cable optical fiber temperature data set, and defining the settlement analysis temperature observation point and the settlement analysis temperature reference point includes: The temperature change rate of the data points in the dynamic submarine cable optical fiber temperature data set is calculated by the finite difference method, and the calculation formula is: , where k i is the temperature change rate at the i-th target position, t i+1 is the temperature data of the dynamic submarine cable optical fiber at the i+1th target position, t i is the dynamic submarine cable optical fiber temperature data at the i-th target location, x i+1 is the i+1th target position, x i is the i-th target position, N is the number of preset target positions; The temperature change rate difference is calculated according to the temperature change rate and a temperature change rate difference sequence is formed. The calculation formula of the temperature change rate difference is: ,in, is the temperature change rate difference at the i-th target position, k i+1 is the temperature change rate at the i+1th target position; A temperature change rate difference threshold is preset, and after the dynamic submarine cable platform side water entry point, two data points whose temperature change rate difference is less than the temperature change rate difference threshold are sequentially searched in the temperature change rate difference sequence, and the target position corresponding to the first searched data point is used as the dynamic submarine cable platform side mud entry point, and the target position corresponding to the later searched data point is used as the dynamic submarine cable fan side mud entry point; After the data point corresponding to the mud entry point of the dynamic submarine cable wind turbine side, use the sign change detection algorithm in the temperature change rate difference sequence to find the data point where the temperature change rate changes from positive to negative, and use the corresponding target position as the settlement analysis temperature observation point; The data points after the settlement analysis temperature observation point in the temperature change rate difference sequence are traversed, and the data point equal to the dynamic submarine cable optical fiber temperature data of the settlement analysis temperature observation point is defined as the settlement analysis temperature reference point.

5. The dynamic submarine cable settlement monitoring and analysis method according to claim 1 is characterized in that: The seawater temperature stratification is determined according to the temperature difference sequence, wherein the seawater temperature stratification includes a constant temperature layer and a linear layer, and includes: Acquire a layered temperature set, which is a temperature data set of the dynamic submarine cable optical fiber between the water entry point on the dynamic submarine cable platform side and the mud entry point on the dynamic submarine cable platform side, acquire the layered temperature set under the action of low current and extract a data point every 1m to form a temperature sequence, and calculate the difference between adjacent data points in the temperature sequence to form the temperature difference sequence; A temperature difference threshold, a temperature difference mean square error threshold and a temperature difference mean threshold are preset. When the 1st to jth data in the temperature difference sequence are all less than or equal to the temperature difference threshold, the mean square error of the 1st to jth data is less than the temperature difference mean square error threshold, and the mean of the data after the jth data is greater than or equal to the temperature difference mean threshold, the target position corresponding to the jth data is the dividing point between the isothermal layer and the linear layer, and the seawater is divided into the isothermal layer and the linear layer based on the dividing point.

6. The dynamic submarine cable settlement monitoring and analysis method according to claim 1 is characterized in that: The step of obtaining the linear layer optical fiber temperature resolution according to the linear layer depth comprises: Acquire the linear layer depth, when the dynamic submarine cable enters the water in a vertical state, the linear layer depth is the linear layer submarine cable length; Obtain the total temperature difference of the linear layer, and calculate the temperature resolution of the optical fiber of the linear layer based on the linear layer depth and the total temperature difference of the linear layer. The calculation formula is: , where R z is the linear layer fiber temperature resolution in the zth month, is the total temperature difference of the linear layer in the zth month, h z is the linear layer depth of the zth month.

7. The dynamic submarine cable settlement monitoring and analysis method according to claim 1 is characterized in that: The obtaining of the dynamic cable settlement distance based on the dynamic submarine cable optical fiber temperature data set and the linear layer optical fiber temperature resolution comprises: Obtaining a settlement analysis temperature difference, the settlement analysis temperature difference being the temperature difference between the settlement analysis temperature observation point and the settlement analysis temperature reference point, and recording the settlement analysis temperature difference of the Uth month when the dynamic cable is not initially settled in units of five days to form a settlement analysis temperature difference sequence; Obtain the mean value of the settlement analysis temperature difference sequence and the standard deviation of the settlement analysis temperature difference sequence, and calculate the settlement temperature threshold of the dynamic submarine cable. The calculation formula is: , where Q is the temperature threshold of dynamic submarine cable settlement, is the mean value of the temperature difference series of the settlement analysis in the Uth month, is the standard deviation of the temperature difference series in the settlement analysis of month U; When the settlement analysis temperature difference in the uth month is greater than or equal to the dynamic submarine cable settlement temperature threshold, the dynamic submarine cable settles in the uth month. The calculation formula for the dynamic cable monthly settlement distance is: , where H Y is the monthly settlement distance of the dynamic cable, is the temperature difference of the settlement analysis in the uth month, R u is the linear layer fiber temperature resolution in the uth month; Obtain the settlement analysis temperature difference of the sth month in the Sth year and the settlement analysis temperature difference of the sth month in the S-1st year. When the settlement analysis temperature difference of the sth month in the Sth year is greater than the settlement analysis temperature difference of the sth month in the S-1st year, the dynamic submarine cable settles in the Sth year. The calculation formula for the annual settlement distance of the dynamic cable is: , where H is the annual settlement distance of the dynamic cable, is the temperature difference for the settlement analysis in the sth month of the sth year, is the temperature difference of the settlement analysis in the sth month of the sth year, R s is the linear layer fiber temperature resolution in the sth month of the sth year.

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