Power cable non-intrusive load and partial discharge synchronous monitoring method

Abstract

The invention relates to a non-intrusive load and partial discharge synchronous monitoring method for a power cable. The method comprises the steps that S1, a distributed optical fiber high-speed demodulation modulator based on an anti-Stokes fast representation algorithm collects the surface temperature of a cable body; s2, verifying a power cable heat-load inversion calculation model based on a finite element multi-physical field simulation method; s3, passive Fabry-Perot resonance monitoring for cable partial discharge monitoring is carried out; s4, development and engineering application of a power cable load and partial discharge comprehensive monitoring system; compared with a conventional distributed optical fiber sensing system, the power cable transient temperature rapid change monitoring system comprehensively considers cable specifications and external environment variables according to power cable transient temperature rapid change monitoring requirements, is different from a traditional cable current-carrying capacity analysis system, and has the advantages that the power cable transient temperature rapid change monitoring system is simple in structure and convenient to use. The power cable load and partial discharge integrated monitoring system can monitor the partial discharge, temperature rise and load characteristic change of the cable at the same time.

Description

Technical Field

[0001] The present invention belongs to the technical field of non-intrusive load and partial discharge synchronous monitoring of cables, and specifically relates to a method for non-intrusive load and partial discharge synchronous monitoring of power cables; Background Art

[0002] At present, the main way to obtain cable load is still based on current transformers. As a primary power device, current transformers are invasive monitoring technologies with large size, inconvenient installation and maintenance, and are not suitable for underground cable applications. The emerging distributed fiber optic sensing technology uses optical fiber to monitor the surface temperature of power cables in real time, and uses the temperature load inversion algorithm to calculate the load state of the cable. However, there are two technical constraints in the latter. One is that the time response speed of the distributed fiber optic sensing system is very slow, reaching the order of minutes, but the short-circuit fault current will cause the cable temperature to rise rapidly in a short time, so there is a certain gap in time response; second, most of the existing load inversion models use temperature-load comparison tables. For different cable body structures and operating environments, the calculation results have large errors, which is not conducive to obtaining accurate cable loads. On the other hand, the conventional power cable temperature monitoring method is to place discrete temperature sensing devices such as thermocouples in places where cables are prone to failure for temperature monitoring; or to use infrared thermal imaging sensors to detect power cables one by one. Obviously, the traditional method is not only time-consuming and labor-intensive, but also the electrical sensors have poor anti-electromagnetic interference ability and low insulation performance. The partial discharge monitoring of power cables generally adopts ultrasonic detection method, pulse current detection method, differential method, etc. In actual work, this method has many limiting factors such as low accuracy and difficulty in obtaining power on site. Summary of the invention

[0003] A non-intrusive load and partial discharge synchronous monitoring method for power cables, characterized in that: finite element multi-physics field simulation technology is used to construct heat-load inversion models of power cables of different types in different application scenarios, and the surface temperature of the cable body is obtained by distributed optical fiber sensors to calculate the load state of the cable, providing an effective basis for power load scheduling; effective monitoring of cable partial discharge is achieved by FP optical fiber sensors, and the specific work content includes the following:

[0004] S1: Distributed optical fiber high-speed demodulator based on anti-Stokes fast characterization algorithm collects the surface temperature of the cable body;

[0005] a. The principle of optical fiber high-speed demodulator is based on the anti-Stokes fast characterization algorithm model and verification;

[0006] b. Fiber optic high-speed demodulator includes distributed fiber optic sensor demodulation system software and distributed fiber optic high-speed demodulator;

[0007] S2: Verification of the power cable heat-load inverse calculation model based on the finite element multi-physics field simulation method;

[0008] a. Establishment of finite element multi-physics field simulation physical model;

[0009] b. Selection of electrical and thermal parameters in multiple models / complex environments;

[0010] c. Practical verification of the power cable heat-load inversion calculation model;

[0011] S3: Passive Fabry-Perot resonance monitoring for cable partial discharge monitoring;

[0012] a. Fabry-Perot resonance characteristic test;

[0013] b. Partial discharge monitoring based on Fabry-Perot resonance sensor;

[0014] S4: Development and engineering application of comprehensive monitoring system for power cable load and partial discharge:

[0015] a. Development of comprehensive monitoring system for power cable load and partial discharge;

[0016] b. Pilot application of comprehensive monitoring system for power cable load and partial discharge.

[0017] Beneficial effects: Compared with conventional distributed optical fiber sensing systems, the present invention is aimed at monitoring the rapid changes in transient temperature of power cables. There is a large error in the correspondence between the surface temperature and load of traditional cables. The present invention will comprehensively consider the cable specifications and external environmental variables, and perform cable heat-load inversion calculation based on finite element multi-physics field simulation technology, which can effectively improve the accuracy of load calculation. By utilizing the sensitivity of FP resonance technology to sound waves, the present invention is different from traditional cable current-carrying capacity analysis systems in that it can simultaneously monitor changes in cable local discharge, temperature rise and load characteristics. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 : Flow chart of the steps of the present invention;

[0019] Figure 2 : Schematic diagram of the structure of the FP optical fiber sensor of the present invention;

[0020] Figure 3 : Module connection diagram;

[0021] Figure 4 ; Software organization diagram. DETAILED DESCRIPTION

[0022] A non-intrusive load and partial discharge synchronous monitoring method for power cables, characterized in that: finite element multi-physics field simulation technology is used to construct heat-load inversion models of power cables of different types in different application scenarios, and the surface temperature of the cable body is obtained by distributed optical fiber sensors to calculate the load state of the cable, providing an effective basis for power load scheduling; effective monitoring of cable partial discharge is achieved by FP optical fiber sensors, and the specific work content includes the following:

[0023] S1: Distributed optical fiber high-speed demodulator based on anti-Stokes fast characterization algorithm collects the surface temperature of the cable body;

[0024] Firstly, the relationship between anti-Stokes light intensity and ambient temperature is used to expand the characterization algorithm, and the fiber optic temperature measurement under the new algorithm is calibrated using a high and low temperature chamber to optimize and verify the effectiveness of the algorithm. Secondly, the constraint relationship between the characteristic parameters of the distributed fiber optic temperature sensing system is theoretically analyzed. Under the clear target requirement of high-speed response, the parameters are readjusted and a new hardware system is built. Finally, the loss and temperature resistance of the optical fiber are tested to complete the test of the overall temperature measurement error and response time.

[0025] a. The principle of optical fiber high-speed demodulator is based on the anti-Stokes fast characterization algorithm model and verification;

[0026] b. Fiber optic high-speed demodulator includes distributed fiber optic sensor demodulation system software and distributed fiber optic high-speed demodulator;

[0027] S2: Verification of the power cable heat-load inverse calculation model based on the finite element multi-physics field simulation method;

[0028] Firstly, the physical structure models of various types of XLPE cables are constructed using COMSOL multi-physics field simulation software. In the mathematical model, the heating characteristics of the cable are obtained based on the conductor loss, insulation loss and metal sheath loss, and the mathematical models of the temperature field and fluid field under steady-state and transient conditions are further constructed. Then, according to the underground cable operation links and the cable body structure, appropriate simulation parameters are selected according to the results of literature research. Finally, the algorithm is packaged into load analysis software, and the effectiveness test of the third party is carried out.

[0029] a. Establishment of finite element multi-physics field simulation physical model;

[0030] b. Selection of electrical and thermal parameters in multiple models / complex environments;

[0031] c. Practical verification of the power cable heat-load inversion calculation model;

[0032] S3: Passive Fabry-Perot resonance monitoring for cable partial discharge monitoring;

[0033] Firstly, the vibration response range and minimum response capacity of the FP cavity are tested on a high-speed vibration platform. Based on the existing expression characteristics of the relationship between discharge and acoustics, the discharge signal range that the FP cavity can obtain is clarified. On this basis, the FP cavity and optical fiber are packaged as a whole to form a vibration sensor, and a corresponding signal demodulator is developed.

[0034] a. Fabry-Perot resonance characteristic test;

[0035] b. Partial discharge monitoring based on Fabry-Perot resonance sensor;

[0036] S4: Development and engineering application of comprehensive monitoring system for power cable load and partial discharge:

[0037] Firstly, the above research results are effectively integrated to form a comprehensive monitoring system for power cable load and partial discharge. The monitoring layer of the system includes three subsystems: cable temperature, load, and partial discharge monitoring. The communication method mainly adopts 485 bus and Ethernet on the physical link, and follows standard communication protocols on the data link, such as 101 / 104 / IEC61850; the data layer includes data collection, analysis and database establishment; the application layer is based on the above research results to realize partial discharge and load monitoring; the system function adopts an intuitive guided interface to guide the hierarchical management mode; the interactive interface is written in C / C++ language; finally, the present invention will select a pilot to conduct a pilot application of the comprehensive monitoring system for power cable load and partial discharge.

[0038] a. Development of comprehensive monitoring system for power cable load and partial discharge;

[0039] b. Pilot application of comprehensive monitoring system for power cable load and partial discharge;

[0040] S1: Distributed optical fiber high-speed demodulator based on anti-Stokes fast characterization algorithm collects the surface temperature of the cable body; the specific method is: Optical time domain reflectometry (OTDR) measurement technology can obtain information such as the length, loss, and breakage of the optical fiber by detecting the scattered signal in the optical fiber, and is widely used in the field of optical fiber communication; assuming that the distance from the position of the scattered light to the incident end of the optical fiber is L, then

[0041]

[0042] Where c is the speed of light in vacuum, which is 3×10 8 m / s; n is the effective refractive index of the optical fiber, △t is the time required for the light signal to travel from the incident end of the optical fiber to the scattered signal at L and return to the incident end, V g is the group velocity of the transmitted light; the total light intensity at the optical fiber L is:

[0043] Pt (L) = P i exp(-αL)2

[0044] Among them, P i is the incident light intensity, α is the total transmission loss, and α is the scattering loss s and absorption loss α a Composition; the scattered light intensity at this time is:

[0045] P ts (L) = α i P t (L)V g w 3

[0046] Where w is the pulse width of the incident light; the intensity of the backscattered light is:

[0047]

[0048] Here, NA is the numerical aperture of the optical fiber, which is used to measure the ability of the optical fiber incident end to collect light, and its calculation method is:

[0049]

[0050] n1 and n2 are the refractive indices of the core and cladding, respectively;

[0051] Raman-type distributed optical fiber sensing system is based on OTDR, which demodulates the intensity of Raman scattering signal in optical fiber to obtain the temperature distribution information of optical fiber. In Raman-type distributed optical fiber sensing system, Raman ratio is used to calculate the temperature on optical fiber. Raman ratio is the intensity of anti-Stokes light (I as ) and the intensity of Stokes light (I s ) ratio; the light intensities of the two can be expressed by equations 3-6 and 3-7:

[0052]

[0053]

[0054] In the formula, h is Planck's constant, which is 6.63×10 -34 J·s; k is the Boltzmann constant, which is 1.38×10 -23 J / K; △v is the Raman frequency shift; K s and K as are the position-dependent scattering loss factors of Stokes light and anti-Stokes light respectively; the scattering loss factor is the superposition of the losses caused by non-temperature factors such as optical fiber transmission loss and bending loss;

[0055] Furthermore, the Raman ratio is:

[0056]

[0057] Then the temperature at any position along the measuring optical fiber is:

[0058]

[0059] In the formula, T0 is the reference temperature measured by the reference optical fiber; it can be seen that the Raman distributed optical fiber sensing system is only sensitive to temperature, and the strain of the optical fiber has no effect on the temperature measurement of the system;

[0060] During the temperature characterization process, the calculation of the Raman ratio will consume a large amount of system resources of the demodulation equipment, which will reduce the overall temperature response speed of the system. If the optical fiber can better shield the external environmental stress, the anti-Stokes method can be directly used for rapid temperature characterization.

[0061] S2: Verification of the power cable heat-load inverse calculation model based on the finite element multi-physics field simulation method; the specific method is:

[0062] According to the basic laws of thermodynamics, when there is a temperature difference in a system, a heat exchange process from high temperature to low temperature will occur inside the system; the heat exchange methods are divided into three types: heat conduction, heat convection, and heat radiation;

[0063] The heat exchange mode of heat conduction is mostly the transfer of heat from a higher temperature to a lower temperature. The heat exchange law of heat conduction can be expressed by Fourier's law, as shown in formula 3-10;

[0064]

[0065] In the formula, q c is the conduction heat flux density; k is the thermal conductivity; is the temperature gradient per unit area;

[0066] During the operation of the cable, air flows over the cable surface and takes away some heat. This heat transfer mode is called convective heat transfer. According to different causes, convective heat transfer can be divided into natural convection and forced convection. Natural convection is caused by different internal temperatures of the fluid and has nothing to do with external forces. Forced convection is the flow of fluid caused by external forces such as fans. For cable tunnels with fans turned on, the convective heat transfer mode is forced convection, and the heat flux density is shown in formula 11.

[0067] q d =h(T1-T2)11

[0068] In the formula, h is the convection heat transfer coefficient; T1 is the fluid temperature; T2 is the surface temperature of the object;

[0069] Thermal radiation refers to the heat transfer process in which an object has temperature and generates radiated electromagnetic waves, and the higher the temperature, the greater the thermal radiation;

[0070] There are three ways of heat transfer in underground cables: heat conduction, convection and radiation. Heat conduction occurs inside the cable body, between the underground pipe gallery and the surrounding soil. Since ventilation devices are installed in the cable tunnel, the heat transfer process between the air and the cable surface is mainly forced convection. Compared with convection heat transfer, heat radiation between the cable surface and the tunnel wall has less effect on temperature.

[0071] S3: Passive Fabry-Perot resonance monitoring for cable partial discharge monitoring; the specific method is:

[0072] The optical fiber sensor used for partial discharge monitoring adopts the FP (Fabry-Perot) interference principle. The light emitted by the broadband light source enters the sensor through optical fiber coupling, and is reflected on the silicon wafer and reflective layer surface of the sensor FP cavity to form double-beam interference. When the mechanical wave vibration generated by the local discharge acts on the surface of the silicon film to deform it, the air gap of the FP cavity changes, that is, the cavity length d changes, resulting in changes in the spectrum of the interference signal. The cavity length d can be obtained through the optical fiber white light interferometric demodulation technology, thereby obtaining the partial discharge characteristics.

[0073] According to the white light interferometry technique, the sensor cavity length λ1 and λ2 are the wavelengths of adjacent peaks in the spectrum (phase difference 2π), n is the refractive index of the medium; the reflected light intensity I in the reflection spectrum r With the projected light intensity I t They are:

[0074]

[0075]

[0076] In the formula, the optical path difference λ is the wavelength of light in vacuum (m); n is the refractive index of the medium of the FP cavity; d is the length of the FP cavity (nm) is the fineness, which is related to the reflectivity R. The higher the reflectivity, the higher the fineness;

[0077] The deformation formula of the elastic diaphragm of the optical fiber FP sensor is:

[0078]

[0079] Where, ω(l) is the deflection of the diaphragm; P is the pressure on the diaphragm (N); μ is the Poisson's ratio; E is the Young's modulus; h is the thickness of the diaphragm (nm); r is the effective radius of the film (nm); l is the radius of any part of the silicon membrane (nm);

[0080] At the center point of the diaphragm, i.e., l=0, the pressure sensitivity Y expression can be obtained as:

[0081]

[0082] The change in pressure can be calculated based on the change in the FP cavity length and the pressure sensitivity Y, and the pressure value at the current moment can be further calculated.

[0083] Figure 3 A schematic diagram of a non-intrusive load and partial discharge synchronous monitoring device for a power cable provided in an embodiment of the present application is shown in FIG. Figure 3 As shown, the device comprises:

[0084] The temperature acquisition module 11 is used to collect the surface temperature of the cable body using a distributed optical fiber sensor;

[0085] A model building module 22, used to build a power cable heat-load inversion calculation model based on a finite element multi-physics field simulation method;

[0086] The partial discharge detection module 33 is used to monitor the partial discharge of the cable based on optical fiber sensing.

[0087] The above device can execute the non-intrusive load and partial discharge synchronous monitoring method of power cable in the above embodiment, wherein the temperature acquisition module 11 executes step S1; the model building module 22 executes step S2; and the partial discharge detection module 33 executes step S3.

[0088] Based on the same inventive concept, an electronic device is also provided in an embodiment of the present application, and the method corresponding to the electronic device may be the model training method and the traffic screening method for traffic screening in the aforementioned embodiment, and its principle of solving the problem is similar to that of the method. The electronic device provided in an embodiment of the present application includes: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor can execute the methods and / or technical solutions of the aforementioned multiple embodiments of the present application.

[0089] The electronic device may be a user device, or a device formed by integrating a user device and a network device through a network, or may be an application running on the above device. The user device includes but is not limited to various terminal devices such as computers, mobile phones, tablet computers, smart watches, and bracelets. The network device includes but is not limited to network hosts, single network servers, multiple network server sets, or cloud computing-based computer sets, which can be used to implement some processing functions when setting an alarm. Here, the cloud is composed of a large number of hosts or network servers based on cloud computing, where cloud computing is a type of distributed computing, a virtual computer composed of a group of loosely coupled computer sets.

[0090] Figure 4 The structure of a device suitable for implementing the method and / or technical solution in the embodiment of the present application is shown, and the device 1200 includes a central processing unit (CPU, Central Processing Unit) 1201, which can perform various appropriate actions and processes according to the program stored in the read-only memory (ROM, Read Only Memory) 1202 or the program loaded from the storage part 1208 to the random access memory (RAM, Random Access Memory) 1203. In RAM1203, various programs and data required for system operation are also stored. CPU 1201, ROM 1202 and RAM 1203 are connected to each other through bus 1204. Input / output (I / O, Input / Output) interface 1205 is also connected to bus 1204.

[0091] The following components are connected to the I / O interface 1205: an input section 1206 including a keyboard, a mouse, a touch screen, a microphone, an infrared sensor, etc.; an output section 1207 including a cathode ray tube (CRT), a liquid crystal display (LCD), an LED display, an OLED display, etc., and a speaker, etc.; a storage section 1208 including one or more computer-readable media such as a hard disk, an optical disk, a magnetic disk, a semiconductor memory, etc.; and a communication section 1209 including a network interface card such as a LAN (Local Area Network) card, a modem, etc. The communication section 1209 performs communication processing via a network such as the Internet.

[0092] In particular, the methods and / or embodiments in the embodiments of the present application may be implemented as computer software programs. For example, the embodiments disclosed in the present application include a computer program product, which includes a computer program carried on a computer-readable medium, and the computer program includes program code for executing the method shown in the flowchart. When the computer program is executed by the central processing unit (CPU) 1201, the above functions defined in the method of the present application are executed.

[0093] Another embodiment of the present application further provides a computer-readable storage medium having computer program instructions stored thereon, wherein the computer program instructions can be executed by a processor to implement the methods and / or technical solutions of any one or more embodiments of the present application described above.

[0094] Specifically, the present embodiment can adopt any combination of one or more computer-readable media. Computer-readable media can be computer-readable signal media or computer-readable storage media. Computer-readable storage media can be, for example, but not limited to, electrical, magnetic, optical, electromagnetic, infrared, or semiconductor systems, devices or devices, or any combination of the above. More specific examples (non-exhaustive lists) of computer-readable storage media include: electrical connections with one or more wires, portable computer disks, hard disks, random access memories (RAM), read-only memories (ROM), erasable programmable read-only memories (EPROM or flash memory), optical fibers, portable compact disk read-only memories (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination of the above. In this document, computer-readable storage media can be any tangible medium containing or storing programs, which can be used by instruction execution systems, devices or devices or used in combination with them.

[0095] 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.

[0096] The program code embodied on the computer readable medium may be transmitted using any appropriate medium, including but not limited to wireless, wireline, optical fiber cable, RF, etc., or any suitable combination of the foregoing.

[0097] The computer program code for performing the operation of the present application can be written in one or more programming languages ​​or a combination thereof, including object-oriented programming languages ​​such as Java, Smalltalk, C++, and also conventional procedural programming languages ​​such as "C" language or similar programming languages. The program code can be executed entirely 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 a remote computer, or completely on a 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 can be connected to an external computer (e.g., using an Internet service provider to connect through the Internet).

[0098] The flow chart or block diagram in the accompanying drawings shows the possible architecture, function and operation of the equipment, method and computer program product according to various embodiments of the present application. In this regard, each square box in the flow chart or block diagram can represent a module, a program segment or a part of a code, and the module, the program segment or a part of the code contains one or more executable instructions for realizing the specified logical function. It should also be noted that in some implementations as replacements, the functions marked in the square box can also occur in a sequence different from that marked in the accompanying drawings. For example, two square boxes represented in succession can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each square box in the block diagram and / or flow chart, and the combination of the square boxes in the block diagram and / or flow chart can be implemented with a dedicated system for hardware that performs a specified function or operation, or can be implemented with a combination of dedicated hardware and computer instructions.

[0099] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0100] In the several embodiments provided in the present application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation. For example, multiple units or page components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interfaces, devices or units, which can be electrical, mechanical or other forms.

[0101] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0102] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of hardware plus software functional units.

[0103] The above-mentioned integrated unit implemented in the form of a software functional unit can be stored in a computer-readable storage medium. The above-mentioned software functional unit is stored in a storage medium, including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) or a processor to perform some steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (Read-Only Memory, ROM), random access memory (Random Access Memory, RAM), disk or optical disk and other media that can store program codes.

[0104] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

[0105] In addition, it is clear that the word "comprising" does not exclude other units or steps, and the singular does not exclude the plural. Multiple units or devices stated in a device claim can also be implemented by one unit or device through software or hardware. The words first, second, etc. are used to indicate names, and do not indicate any particular order.

Claims

1. A method for synchronously monitoring non-intrusive load and partial discharge of power cables, characterized in that: include: S1: Use distributed optical fiber sensors to collect the surface temperature of the cable body; S2: Construct a heat-load inversion calculation model for power cables based on finite element multi-physics field simulation method; S3: Monitoring partial discharge in cables based on optical fiber sensing.

2. A method for synchronously monitoring non-intrusive load and partial discharge of a power cable according to claim 1, characterized in that: S1: Collecting the cable body surface temperature using a distributed optical fiber sensor further includes: Construct a model based on anti-Stokes fast characterization algorithm; Establishing a distributed optical fiber high-speed demodulation system, wherein the distributed optical fiber high-speed demodulation system is provided with the anti-Stokes-based fast characterization algorithm model; A distributed optical fiber sensor is configured, wherein the distributed optical fiber high-speed demodulation system is arranged in the distributed optical fiber sensor.

3. A method for synchronously monitoring non-intrusive load and partial discharge of power cables according to claim 2, characterized in that: The construction of the anti-Stokes fast characterization algorithm model further includes: Detect the scattered signal in the optical fiber and obtain the length, loss, and breakage information of the optical fiber. Assuming the distance from the position of the scattered light to the incident end of the optical fiber is L, we have Where c is the speed of light in vacuum, which is 3×10 8 m / s; n is the effective refractive index of the optical fiber, △t is the time required for the light signal to travel from the incident end of the optical fiber to the scattered signal at L and return to the incident end, V g is the group velocity of the transmitted light; the total light intensity at the optical fiber L is: P t (L)=P i exp(-αL)2 Among them, P i is the incident light intensity, α is the total transmission loss, and α is the scattering loss s and absorption loss α a Composition; the scattered light intensity at this time is: P ts (L)=α i P t (L)V g w 3 Where w is the pulse width of the incident light; the intensity of the backscattered light is: Here, NA is the numerical aperture of the optical fiber, which is used to measure the ability of the optical fiber incident end to collect light, and its calculation method is: n1 and n2 are the refractive indices of the core and cladding, respectively; Based on optical time domain reflectometry, the intensity of the Raman scattering signal in the optical fiber is demodulated, and the temperature on the optical fiber is calculated using the Raman ratio; the Raman ratio is the intensity of the anti-Stokes light (I as ) and the intensity of Stokes light (I s ) ratio; the light intensity of the two is: In the formula, h is Planck's constant, which is 6.63×10 -34 J·s; k is the Boltzmann constant, which is 1.38×10 - 23 J / K; △v is the Raman frequency shift; K s and K as are the position-dependent scattering loss factors of Stokes light and anti-Stokes light respectively; the scattering loss factor is the superposition of the losses caused by non-temperature factors such as optical fiber transmission loss and bending loss; The Raman ratio is: Then the temperature at any position along the measuring optical fiber is: Where T0 is the reference temperature measured by the reference optical fiber.

4. The method for synchronously monitoring non-intrusive load and partial discharge of a power cable according to claim 1, characterized in that: S2: The heat-load inversion calculation model of power cables based on the finite element multi-physics field simulation method further includes: Construct finite element multi-physics field simulation physical model; Calculate electrical and thermal parameters in multiple models / complex environments; Construct a heat-load inversion calculation model for power cables.

5. A method for synchronously monitoring non-intrusive load and partial discharge of power cables according to claim 4, characterized in that: The construction of the power cable heat-load inversion calculation model further includes: The heat exchange method of heat conduction is that heat is transferred from a higher temperature to a lower temperature. The heat exchange law of heat conduction is described by Fourier's law: In the formula, q c is the conduction heat flux density; k is the thermal conductivity; is the temperature gradient per unit area; The cable generates convection heat transfer during operation, which includes natural convection and forced convection. For the cable tunnel with the fan started, the convection heat transfer mode is forced convection, and the heat flux density is: q d =h(T1-T2)11 In the formula, h is the convection heat transfer coefficient; T1 is the fluid temperature; T2 is the surface temperature of the object; The heat transfer modes of underground cables include heat conduction, convection and heat radiation.

6. A method for synchronously monitoring non-intrusive load and partial discharge of a power cable according to claim 1, characterized in that: S3: Monitoring of partial discharge in cables based on optical fiber sensing further includes: The Fabry-Perot interference principle is used to test the cable resonance characteristics; The configuration is based on a Fabry-Perot resonant sensor for partial discharge monitoring of cables.

7. A method for synchronously monitoring non-intrusive load and partial discharge of a power cable according to claim 5, characterized in that: The cable resonance characteristic test using the Fabry-Perot interference principle further includes: Using the Fabry-Perot interference principle, the light emitted by the broadband light source enters the sensor through optical fiber coupling, and is reflected on the silicon chip and reflective layer surface of the sensor FP cavity to form double-beam interference; The cavity length d can be obtained by optical fiber white light interferometric demodulation technology, and the local discharge characteristics can be obtained; According to the white light interferometry technique, the sensor cavity length λ1 and λ2 are the wavelengths of adjacent peaks in the spectrum (phase difference 2π), n is the refractive index of the medium; the reflected light intensity I in the reflection spectrum r With the projected light intensity I t They are: In the formula, the optical path difference λ is the wavelength of light in vacuum (m); n is the refractive index of the medium of the FP cavity; d is the length of the FP cavity (nm) is the fineness, which is related to the reflectivity R. The higher the reflectivity, the higher the fineness; The deformation formula of the elastic diaphragm of the optical fiber FP sensor is: Where, ω(l) is the deflection of the diaphragm; P is the pressure on the diaphragm (N); μ is the Poisson's ratio; E is the Young's modulus; h is the thickness of the diaphragm (nm); r is the effective radius of the film (nm); l is the radius of any part of the silicon membrane (nm); At the center point of the diaphragm, i.e., l=0, the pressure sensitivity Y expression can be obtained as: The change in pressure can be calculated based on the change in the FP cavity length and the pressure sensitivity Y, and the pressure value at the current moment can be further calculated.

8. The method for synchronously monitoring non-intrusive load and partial discharge of a power cable according to claim 1, characterized in that: The method further comprises: according to steps S1, S2 and S3, forming a comprehensive monitoring system for power cable load and partial discharge to monitor the power cable load and partial discharge.

9. A non-intrusive load and partial discharge synchronous monitoring device for power cables, characterized in that: include: A temperature acquisition module is used to collect the surface temperature of the cable body using a distributed optical fiber sensor; Model building module, used to build a power cable heat-load inversion calculation model based on finite element multi-physics field simulation method; Partial discharge detection module, used to monitor partial discharge in cables based on optical fiber sensing.

10. An electronic device for synchronous monitoring of non-intrusive load and partial discharge of power cables, characterized in that: The electronic device includes: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor can execute the method described in any one of claims 1 to 7.

11. A computer readable medium having computer program instructions stored thereon, characterized in that: The computer program instructions can be executed by a processor to implement the method according to any one of claims 1-7.

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